# October 2006

EPA/600/R-05/144bF



# Air Quality Criteria for Lead

Volume II of II

# EPA/600/R-05/144bF

October 2006



# Air Quality Criteria for Lead

Volume II

National Center for Environmental Assessment-RTP Division
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, NC

# PREFACE

National Ambient Air Quality Standards (NAAQS ) are promulgated by the United States

Environm ental Protection Agency (EPA) to meet requirements set forth in Sections 108 and 109

of the U.S. Clean Air Act. Those two Clean Air Act sections require the EPA Administrator

(1) to list widespread air pollutants that reasonabl y m ay be expected to endanger public health or

welfare; (2) to issue air qualit y criteria for them that assess the latest available scientific

information on nature and effects of ambient e xposure to them; (3) to set “primary” NAAQS to

protect human health with ade quate margin of safety and to set “secondary” NAAQS to protect

against welfare effects (e.g., effects on vegeta tion, ecosystems, visibility, climate, manmade

materials, etc); and (5) to peri odically review and revise, as appropriate, the criteria and NAAQS

for a given listed pollutant or class of pollutants.

Lead was first listed in the mid-1970’s as a “criteria air pollutant” requiring NAAQS

regulation. The scientific inform ation pertinent to Pb NAAQS de velopment available at the time

was assessed in the EPA document Air Quality Criteria for Lead ; published in 1977. Based on

the scientific assessments contained in that 1977 lead air quality criteria document (1977 Lead

AQCD), EPA established a 1.5 μg/m 3 

# (maximum quarterly calendar average) Pb NAAQS in

1978.

To meet Clean Air Act requirements noted above for periodic review of criteria and

NAAQS, ne w scientific information published si nce the 1977 Lead AQCD was later assessed in

a revised Lead AQCD and Addendum published in 1986 and in a Supplement to the 1986

AQCD/Addendum published by EPA in 1990. A 1990 L ead Staff Paper, prepared by EPA’s

Office of Air Quality Planning and Standards (OPQPS), drew upon key findings and conclusions

from the 1986 Lead AQCD/Addendum and 1990 Supplement (as well as other OAQPSsponsored lead exposure/risk analyses) in posing options for the EPA Administrator to consider

with regard to possible revision of the Pb NAAQS . However, EPA chose not to revise the Pb

NAAQS at that time. Rather , as part of implementing a broad 1991 U.S. EPA Strategy for

Reducing Lead Exposure, the Agency focused primarily on regulatory and remedial clean-up

efforts to reduce Pb exposure from a variety of non-air sources that posed more extensive public

health risks, as well as other actions to reduce air emissions.

The purpose of this revised Lead AQCD is to critically assess the latest scientific

inform ation that has become available sin ce the literature asse ssed in the 1986 Lead

II-iii

# AQCD/Addendum and 1990 Supplement, with the main focus being on pertinent new

information useful in evaluating health and enviro nmental effects of ambien t air lead exposures.

This includes discussion in this document of information rega rding: the nature, sources,

distribution, measurement, and c oncentrations of lead in the environment; multimedia lead

exposure (via air, food, water, et c.) and biokinetic modeling of c ontributions of such exposures

to concentrations of lead in brain, kidney, a nd other tissues (e.g., blood and bone concentrations,

as key indices of lead exposure).; characterization of l ead health effects and associated exposureresponse relationships; and delineation of environmen tal (ecological) effects of lead. This final

version of the revised Lead AQCD mainly assesses pertinent literature published or accepted for

publication through December 2005.

The First External Review Draft (dated Decem ber 2005) of the revised Lead AQCD

underwent public comment and was reviewed by the Clean Air Scientific Advisory Committee

(CASAC) at a public meeting held in Durham , NC on February 28-March 1, 2006. The public

comments and CASAC recommendations receiv ed were taken into account in making

appropriate revisions and incorporating them in to a Second External Review Draft (dated May,

2006) which was released for further public co mment and CASAC review at a public meeting

held June 28-29, 2006. In addition, still further revised drafts of the Integrative Synthesis

chapter and the Executive Summary were then issued and discussed during an August 15, 2006

CASAC teleconference call. Public commen ts and CASAC advice received on these latter

materials, as well as Second External Review Draf t materials, were taken into account in making

and incorporating further revisions into this fi nal version of this Lead AQCD, which is being

issued to meet an October 1, 2006 court-ordered d eadline. Evaluations c ontained in the present

document provide inputs to an associated Lead Staff Paper prepared by EPA’s Office of Air

Quality Planning and Standards (OAQPS), which poses options for consideration by the EPA

Administrator with regard to proposal and, ul timately, promulgation of decisions on potential

retention or revision, as appropriate, of the current Pb NAAQS.

Preparation of this document has been coordi nated by staff of EPA’s Nat ional Center for

Environmental Assessment in Research Triangl e Park (NCEA-RTP). NCEA-RTP scientific

staff, together with experts from academia, contri buted to writing of docum ent chapters. Earlier

drafts of document materials were reviewed by scientists from other EPA units and by non-EPA

experts in several public peer consultation workshops held by EPA in July/August 2005.

II-iv

# NCEA acknowledges the valuab le contributions provided by authors, contributors, and

reviewers and the diligence of its staff and contractors in the prep aration of this document. The

constructive comments provided by public comment ers and CASAC that served as valuable

inputs contributing to improved scientific and editorial quality of the document are also

acknowledged by NCEA.

DISCLAIMER

Mention of trade names or commercial produc ts in this docum ent does not constitute

endorsement or recommendation for use.

.

II-v

# Air Quality Criteria for Lead (Second External Review Draft)

VOLUME I

EXECUTIVE SUMMARY

......................................................................................................... E-1

1. INTRODUCTION

........................................................................................................... 1-1

2. CHEMISTRY, SOURCES, AN D TRANSPORT OF LEAD

.......................................... 2-1

3. ROUTES OF HUMAN EXPOSURE TO LEAD AND OBSERVED

ENVIRONMENTAL CONCENTRATIONS

.................................................................. 3-1

4. TOXICOKINETICS, BIOLOGICAL MARKERS, AND MODELS OF LEAD

BURDEN I N HUMANS

.................................................................................................. 4-1

5. TOXICOLOGICAL EFFECTS OF LEAD IN LABORATORY ANIMALS

AND IN VITRO TE ST SYSTEMS

................................................................................. 5-1

6. EPIDEMIOLOGIC STUDIES OF HUMAN HEALTH EFFECTS

ASSOCIATED W ITH LEAD EXPOSURE

.................................................................... 6-1

7. ENVIRONMENTAL EFFECTS OF LEAD

................................................................... 7-1

8. INTEGRATIVE SYNTHESIS OF LEAD EXPOSURE/HEALTH

EFFECTS INFORM ATION

............................................................................................ 8-1



# VOLUME II

CHAPTER 4 ANNEX (TOXICOKINETICS , BIOLOGICAL MARKERS, AND
MODELS OF LEAD BURDEN IN HUMANS) ............................................. AX4-1

CHAPTER 5 ANNEX (TOXICOLOGICAL EFFECTS OF LEAD IN

LABORATORY ANIM ALS AND IN VITRO TEST SYSTEMS) ................ AX5-1

CHAPTER 6 ANNEX (EPIDEMIOLOGIC ST UDIES OF HUMAN HEALTH

EFFECTS ASSOCIATED WITH LEAD EXPOSURE) ................................. AX6-1

CHAPTER 7 ANNEX (ENVIRONMENTA L E FFECTS OF LEAD).................................. AX7-1

II-vi

# Table of Contents

Page

PREFACE ........................................................................................................................

.......... II- iii

D I SCLAIMER

..................................................................................................................... ....... II-v

List of Tables

................................................................................................................. ............. II-x

Authors, Contributors, and Reviewers..................................................................................... II-xxi

U.S. Environmental Protection Agency Project Team for Development of Air
Quality Criteria for Lead................................................................................................. II-xx vii

U.S. Environmental Protection Agency Science Advisory Board (SAB) Staff
Office Clean Air Scientific Advisory Committee (CASAC)........................................... II-xxix

Abbreviatio ns and Acronyms ................................................................................................ II-xx xi

AX4. CHAPTER 4 ANNEX (TOXICOKIN ETICS, BI OLOGICAL MARKERS,
AND MODELS OF LEAD BURDEN IN HUMANS) ................................... AX4-1

REFERENCES ...................................................................................................... AX4-44

II-vii

# List of Tables

Page

AX4-1 Analytical Methods for Determini ng Lead in Blood, Urine, and Hair ............ AX4-2

AX4-2 Summary of Selected Measurements of PbB Levels in Humans .................... AX4-4

AX4-3 Bone Lead Measurements in Cadavers............................................................ AX4-7

AX4-4 Bone Lead Measurements in Environmentally-Exposed Subjects .................. AX4-9

AX4-5 Bone Lead Measurements in Occupationally-Exposed Subjects................... AX4-12

AX4-6 Bone Lead Contribution to PbB..................................................................... AX4-19

AX4-7 Bone Lead Studies in Pregna nt and Lactating Subjects................................. AX4-22

AX4-8 Bone Lead Studies of Menopausal a nd Middle-aged to Elderly Subjects..... AX4-30

AX4-9 Lead in Deciduous Teeth from Urban and Remote Environments................ AX4-36

AX4-10 Lead in Deciduous Teeth from Polluted Environments................................. AX4-38

AX4-11 Summary of Selected Measurements of Urine Lead Levels in Humans ....... AX4-39

AX4-12 Summary of Selected Measurements of Hair Lead Levels in Humans ......... AX4-42

II-x

# Authors, Contributors, and Reviewers

CHAPTER 4 ANNEX (TOXICOKINETIC S, BIOLOGICAL MARKERS, AND
MODELS OF LEAD BURDEN IN HUMANS)

Chapter Managers/Editors

Dr. James Brown—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Principal Authors

Dr. Brian Gulson—Graduate School of the Environm ent, Macquarie University
Sydney, NSW 2109, Australia

Contributors and Reviewers

Dr. Lester D. Grant—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. John Vandenberg—National Center for Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

CHAPTER 5 ANNEX (TOXICOLOGICAL EFFECT S OF LEAD IN HUMANS
AND LABORATORY ANIMALS)

Chapter Managers/Editors

Dr. Anuradha Mudipalli—National Center for E nvironmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Srikanth Nadadur—National Center for Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Lori W hite—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Principal Authors

Dr. Anuradha Mudipalli—National Center for E nvironmental Assessment (B243-01),

U.S. Environmental Protection Agency, Resear ch Triangle Park, NC 27711 (Sections 5-2, 5-10)

II-xxi

# Authors, Contributors, and Reviewers

(cont’d)

Principal Authors
(cont’d)

Dr. Stephen Lasley—Dept. of Biomedical and Ther apeu tic Sciences, Univ. of Illinois College of

Medicine, PO Box 1649, Pe oria, IL 61656 (Section 5.3)

Dr. Lori White—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Re search Triangle Park, NC 27711 (Section 5.3)

Dr. Gary Diamond— Syracuse Research Co rporation, 8191 Cedar Street, Akron, NY 14001
(Section 5.4)

Dr. N.D. Vaziri—Division of Nephrology and Hype rtension, University of California – Irvine
Medical Center, 101, The City Drive, Bldg 53, Room #125. Orange, CA 92868 (Section 5.5)

Dr. John Pierce Wise, Sr.—Maine Center fo r Toxicology and Environmental Health,
Departm ent of Applied Medical Sciences, 96 Falmouth Street, PO Box 9300, Portland, ME
04104-9300 (Section 5.6)

Dr. Harvey C. Gonick—David Geffen School of Medicine, University of California at
Los Angeles, 201 Tavistock Ave, Los Angeles, CA 90049 (Sections 5.7, 5.11)

Dr. Gene E. Watson—University of Rocheste r Medical Center, Box 705, Rochester, NY 14642
(Section 5.8)

Dr. Rodney Dietert—Institute for Comparativ e and Environ mental Toxicology, College of
Veterinary Medicine, Cornell Univ ersity, Ithaca, NY 14853 (Section 5.9 )

Contributors and Reviewers

Dr. Lester D. Grant—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Paul Reinhart—Nationa l Center for Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Michael Davis—Nationa l Center for Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. David A. Lawrence—Dept of Environmental and Clinical Imm unology, Empire State Plaza

P.O. Box 509, Albany, NY 12201

II-xxii

# Authors, Contributors, and Reviewers

(cont’d)

Contributors and Reviewers
(cont’d)

Dr. Michael J. McCabe, Jr.—Dept of Environm e ntal Medicine, University of Rochester,

575 Elmwood Avenue, Rochester, NY 14642

Dr. Theodore I. Lidsky—New York State Inst itute for Basic Research, 1050 Forest RD,

Staten Island, NY 10314

Dr. Mark H. Follansbee—Syracuse Research Corporation, 8191 Cedar St. Akron, NY 14001

Dr. William K. Boyes—National Health and En v ironmental Effects Research Laboratory,

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Philip J. Bushnell—National Health and Environmental Effects Research Laboratory,

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Ms. Beth Hassett-Sipple—Office of Air Quality Planning and Standards, U.S. Environm ental
Protection Agency, Research Triangle Park, NC 27711

Dr. Zachary Pekar—Office of Air Quality Pla nning and Standards, U.S. Environm ental
Protection Agency, Research Triangle Park, NC 27711

Dr. John Vandenberg—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

CHAPTER 6 ANNEX (EPIDEMIOLOGICA L STUDIES OF AMBI ENT LEAD
EXPOSURE EFFECTS)

Chapter Managers/Editors

Dr. Jee Young Kim—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Dennis Kotchmar—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. David Svendsgaard—National Center for E nvironmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

II-xxiii

# Authors, Contributors, and Reviewers

(cont’d)

Principal Authors

Dr. David Bellinger—Children’s Hospital, Fa rley Basem ent, Box 127, 300 Longwood Avenue,
Boston, MA 02115 (Section 6.10)

Dr. Margit Bleecker—Center for Occupational and Environ mental Neurology, 2 Hamill Road,
Suite 225, Baltimore, MD 21210 (Section 6.3)

Dr. Gary Diamond— Syracuse Resear ch Corporation, 8191 Cedar Street.

Akron, NY 14001 (Section 6.8, 6.9)

Dr. Kim Dietrich—University of Cincinnati College of Medicine, 3223 E den Avenue,
Kettering Laboratory, Room G31, Cincinnati, OH 45267 (Section 6.2)

Dr. Pam Factor-Litvak—Columbia University Mailm an School of Public Health, 722 West
168th Street, Room 1614, New York, NY 10032 (Section 6.6)

Dr. Vic Hasselblad—Duke University Medica l Center, Durham, NC 27713 (Section 6.10)

Dr. Stephen J. Rothenberg—CINVESTAV-IPN, Mé rida, Yuc atán, México & National Institute
of Public Health, Cuernavaca, Morelos, Mexico (Section 6.5)

Dr. Neal Simonsen—Louisiana State University Hea lth Sciences Center, School of Public Health
& Stanley S Scott Cancer Center, 1600 Cana l Street, Suite 800, New Orleans, LA 70112
(Section 6.7)

Dr. Kyle Steenland—Rollins School of Public Health, Em ory University, 1518 Clifton Road,
Room 268, Atlanta, GA 30322 (Section 6.7)

Dr. Virginia Weaver—Johns Hopkins Bloomberg School of Public Health, 615 North W olfe
Street, Room 7041, Baltimore, MD 21205 (Section 6.4)

Contributors and Reviewers

Dr. J. Michael Davis—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Lester D . Grant—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Kazuhiko Ito—Nelson Institute of Environmental Medicine, Ne w York University School of

Medicine, Tuxedo, NY 10987

II-xxiv

# Authors, Contributors, and Reviewers

(cont’d)

Contributors and Reviewers
(cont’d)

Dr. Kathryn Mahaffey—Office of Prevention, Pesticides and Toxic Substances,

U.S. Environmental Protection Agency, Washington, DC 20460

Dr. Karen Martin—Office of Air Quality Pl anning and Standards, U.S. Environm ental Protection Agency, Research Triangle Park, NC 27711

Dr. Zachary Pekar—Office of Air Quality Pla nning and Standards, U.S. Environm ental
Protection Agency, Research Triangle Park, NC 27711

Ms. Beth Hassett-Sipple—Office of Air Quality Planning and Standards, U.S. Environm ental
Protection Agency, Research Triangle Park, NC 27711

Dr. John Vandenberg—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

CHAPTER 7 ANNEX (ENVIRONME NTAL EFFECTS OF LEAD)

Chapter Manager/Editor

Dr. Timothy Lewis—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Principle Authors

Dr. Ruth Hull—Cantox Environmental Inc., 190 0 Minnesota Court, Suite 130, Mississauga,

Ontario, L5N 3C9 Cana da (Section 7.1)

Dr. James Kaste—Department of Earth Sciences , Dartm outh College, 352 Main Street, Hanover,
NH 03755 (Section 7.1)

Dr. John Drexler—Department of Geological Sc iences, Univ ersity of Colorado, 1216 Gillespie
Drive, Boulder, CO 80305 (Section 7.1)

Dr. Chris Johnson—Department of Civil and Envir onm ental Engineering, Syracuse University,
365 Link Hall, Syracuse, NY 13244 (Section 7.1)

Dr. William Stubblefield—Parametrix, Inc. 3397 2 Texas St. SW, Albany, OR 97321
(Section 7.2)

II-xxv

# Authors, Contributors, and Reviewers

(cont’d)

Principle Authors
(cont’d)

Dr. Dwayne Moore—Cantox Environmental, Inc., 1550A Laperriere Avenue, Suite 103,
Ottawa, Ontario, K1Z 7T2 Canada (Section 7.2)

Dr. David Mayfield—Parametrix, Inc., 411 108th Ave NE, Suite 1800, Bellevue, WA 98004
(Section 7.2)

Dr. Barbara Southworth—Menzie-Cura & Associ ates, Inc., 8 W inchester Place, Suite 202,
Winchester, MA 01890 (Section 7.3)

Dr. Katherine Von Stackleberg—Menzie-Cura & A ssociates, Inc., 8 W inchester Place, Suite
202, Winchester, MA 01890 (Section 7.3)

Contributors and Reviewers

Dr. Jerome Nriagu—Department of Environmenta l Health S ciences, 109 South Observatory,
University of Michigan, Ann Arbor, MI 48109

Dr. Judith Weis—Department of Biol ogy, Rutgers University, Newark, NJ 07102

Dr. Sharon Harper—National Exposure Research Laboratory (D205-05), U.S. Environm ental
Protection Agency, Research Triangle Park, NC 27711

Dr. Karen Bradham—National Research Exposur e Laboratory (D205-05), U.S. Environm ental
Protection Agency, Research Triangle Park, NC 27711

Dr. Ginger Tennant—Of fice of Air Quality Plan ning and Standards, U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711

Ms. Gail Lacey—Office of Air Quality Planning a nd Standards, U.S. Environmental Protection
Agency, Research Triangle Park, NC 27711

Dr. John Vandenberg—National Center for Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

II-xxvi

# U.S. Environmental Protecti on Agency Project Team
for Development of Air Quality Criteria for Lead

Executive Direction

Dr. Lester D. Grant (Director)—National Cent er for Environm ental Assessment-RTP Division,
(B243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Scientific Staff

Dr. Lori White (Lead Team Leader)—Nati onal Center for E nvironmental Assessment
(B243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. James S. Brown—National Center fo r Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Robert Elias—Nationa l Center for Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Re search Triangle Park, NC 27711 (Retired)

Dr. Brooke Hemming—National Center for Environmental Assessment (B243-01), U.S.

Environm ental Protection Agency, Research Triangle Park, NC 27711

Dr. Jee Young Kim—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Dennis Kotchmar—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Timothy Lewis—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Anuradha Muldipalli—National Center for E nvironmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Srikanth Nadadur—National Center for Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Paul Reinhart—Nationa l Center for Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Mary Ross— National Center for Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. David Svendsgaard—National Center for E nvironmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

II-xxvii

# U.S. Environmental Protecti on Agency Project Team

for Dev elopment of Air Quality Criteria for Lead

(cont’d)

Technical Support Staff

Mr. Douglas B. Fennell—Technical Information Sp ecialist, National Center for Environmental

Assessm ent (B243-01), U.S. Environmental Prot ection Agency, Research Triangle Park, NC
27711 (Retired)

Ms. Emily R. Lee—Management Analyst, Natio nal Center for Environm ental Assessment
(B243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Ms. Diane H. Ray—Program Specialist, Natio nal Center for Environm ental Assessment
(B243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Ms. Donna Wicker—Administrative Officer, National Center for Environmental Assessment
(B243-01), U.S. Environm ental Protection Agenc y, Research Triangle Park, NC 27711 (Retired)

Mr. Richard Wilson—Clerk, National Center fo r Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Document Production Staff

Ms. Carolyn T. Perry—Task Order Manager, Com puter Sciences Corpor ation, 2803 Slater Road,

Suite 220, Morrisville, NC 27560

Mr. John A. Bennett—Technical Information Sp ecialist, Library Asso ciates of Maryland,

11820 Parklawn Drive, Suite 400, R ockville, MD 20852

Mr. William Ellis—Records Management Technician, InfoPro, Inc., 8200 Greensboro Drive,

Suite 1450, McLean, VA 22102

Ms. Sandra L. Hughey—Technical Information Sp ecialist, Library Associates of Maryland,

11820 Parklawn Drive, Suite 400, R ockville, MD 20852

Dr. Barbara Liljequist—Technical Editor, Comp uter Sciences Corporation, 2803 Slater Road,

Suite 220, Morrisville, NC 27560

Ms. Michelle Partridge-Doerr—Publications/Gra phics Specialist, TEK System s, 1201 Edwards
Mill Road, Suite 201, Raleigh, NC 27607

Mr. Carlton Witherspoon—Graphic Artist, Comput er Sciences Corporation, 2803 Slater Road,

Suite 220, Morrisville, NC 27560

II-xxviii

# U.S. Environmental Protection Agency
Science Advisory Board (SAB) Staff Office

Clean Air Scientific Advi sory Committee ( CASAC)

Chair

Dr. Rogene Henderson*—Scientist Emeritus, Lovelace Respiratory Research Institute,
Albuquerque, NM

Members

Dr. Joshua Cohen—Faculty, Center for the Evaluati on of Value and Risk, Institute for Clinical
Research and Health Policy Studies, Tuft s New England Medical Center, Boston, MA

Dr. Deborah Cory-Slechta—Director, University of Medicine and Dentistry of New Je rsey and
Rutgers State University, Piscataway, NJ

Dr. Ellis Cowling*—University Distinguished Professor-at-L arge, North Carolina State
University, Colleges of Natural Resources and Agriculture and Life Sciences, North Carolina
State University, Raleigh, NC

Dr. James D. Crapo [M.D.]*—Professor, Departme nt of Me dicine, National Jewish Medical and

Research Center, Denver, CO

Dr. Bruce Fowler—Assistant Director for Scien ce, Division of Toxicology and Environm ental Medicine, Office of the Director, Agency for Toxic Substances and Disease Registry, U.S.

Centers for Disease Control and Pr evention (ATSDR/CDC), Chamblee, GA

Dr. Andrew Friedland—Professo r and Chair, Environmental Studies Program, Dartmouth
College, Hanover, NH

Dr. Robert Goyer [M.D.]—Emeritu s Professor of Pathology, Faculty of Medicine, University of
Western Ontario (Canada), Chapel Hill, NC

Mr. Sean Hays—President, Summ it Toxicology, Allenspark, CO

Dr. Bruce Lanphear [M.D.]—Sloan Professor of Children’s E nvironmental Health, and the

Director of the Cincinnati Ch ildren’s Environmental Health Ce nter at Cincinnati Children’s
Hospital Medical Center and the Univer sity of Cincinnati, Cincinnati, OH

Dr. Samuel Luoma—Senior Research Hydr ologist, U.S. Geological Survey (USGS),

Menlo Park, CA

II-xxix

# U.S. Environmental Protection Agency
Science Advisory Board (SAB) Staff Office

Clean Air Scientific Advi sory Committee ( CASAC)

(cont’d)

Members
(cont’d)

Dr. Frederick J. Miller*—Consultant, Cary, NC

Dr. Paul Mushak—Principal, PB A ssociates, and Visiting P rofessor, Albert Einstein College of
Medicine (New York, NY), Durham, NC

Dr. Michael Newman—Professor of Marine Science, School of Marine S ciences, Virginia
Institute of Marine Science, College of William & Mary, Gloucester Point, VA

Mr. Richard L. Poirot*—Environmental Analyst, Air Pollution Control Di vision, Departm ent of
Environmental Conservation, Vermont Agency of Natural Resources, Waterbury, VT

Dr. Michael Rabinowitz—Geochemist, Marine B iological Laboratory, Woods Hole, MA

Dr. Joel Schwartz—Professor, Environmental H ealth, Harvard University School of Public

Health, Boston, MA

Dr. Frank Speizer [M.D.]*—Edward Kass Professo r of Medicine, Channing Laboratory, Harvard

Medical School, Boston, MA

Dr. Ian von Lindern—Senior Scientist, TerraG raphics Environm enta l Engineering, Inc.,

Moscow, ID

Dr. Barbara Zielinska*—Research Professor, Divi sion of Atmospheric S cience, Desert Research

Institute, Reno, NV

SCIENCE ADVISORY BOARD STAFF

Mr. Fred Butterfield—CASAC Designated Fede ral Officer, 1200 Pennsyl vania Avenue, N.W

., Washington, DC, 20460, Phone: 202-343-9994, Fax: 202-233-0643 (butterfield.fred@epa.gov ) (Physical/Courier/FedEx Address: Fred A. Butterf ield, III, EPA Science Advisory Board Staff
Office (Mail Code 1400F), Woodies Building, 1025 F Street, N.W., Room 3604, Washington,
DC 20004, Telephone: 202-343-9994)

*Members of the statutory Clean Air Scientific Advisory Committee (CASAC) appointed by the

U.S. EPA Administrator



# II-xxx

# Abbreviations and Acronyms

α FGF α -fibroblast growth factor

AA arachidonic acid

AAL active avoidance learning

AAS atomic absorption spectroscopy

ABA β -aminoisobutyric acid

ACBP Achenbach Child Behavior Profile

ACE angiotensin converting enzyme

ACh acetylcholine

AChE acetylcholinesterase

ACR acute-chronic ratio

AD adult

ADC analog digital converter

ADP adenosine diphosphate

AE anion exchange

AEA N -arachidonylethanolamine

AFC antibody forming cells

2-AG 2-arachidonylglycerol

A horizon uppermost layer of soil (litter and humus)

AHR aryl hydrocarbon receptor

AI angiotensin I

ALA * -aminolevulinic acid

ALAD * -aminolevulinic acid dehydratase

ALAS aminolevulinic acid synthetase

ALAU urinary δ -aminolevulinic acid

ALD aldosterone

ALS amyotrophic lateral sclerosis

ALT alanine aminotransferase

ALWT albumin weight

AMEM Alpha Minimal Essential Medium

AMP adenosine monophosphate

ANCOVA analysis of covariance

ANF atrial natriuretic factor

Ang II angiotensin II

ANOVA analysis of variance

II-xxxi

# ANP atrial natriuretic peptide

AP alkaline phosphatase

AP-1 activated protein-1

ApoE apolipoprotein E

AQCD Air Quality Criteria Document

Arg arginine

AS52 cells derived from the CHO cell line

ASGP-R aceyl glycoprotein receptor

AST aspartate aminotransferase

ASV anode stripping voltammetry

3-AT 3-aminotriazole; 3-amino triazide

ATP adenosine triphosphate

ATP1A2 sodium-potassium adenosine triphosphase α 2

ATPase adenosine triphosphatase

ATSDR Agency for Toxic Substances and Disease Research

AVCD atrioventricular conduction deficit

AVS acid volatile sulfide

AWQC ambient water quality criteria

$ beta-coefficient; slope of an equation

$ FGF $ -fibroblast growth factor

17 $ –HS 17 $ -hydroxysteriod

3 $ -HSD 3 $ -hydroxysteriod dehydrogenase

17 $ -HSDH 17 $ -hydroxysteriod dehydrogenase

6 $ -OH-cortisol 6- $ -hydroxycortisol

B both

BAEP brainstem auditory-evoked potentials

BAER brainstem audito ry-evoked responses

BAF bioaccumulation factor

B cell B lymphocyte

BCFs bioconcentration factors

BCS bovine calf serum

BDNF brain derived neurotrophic factor

BDWT body weight changes

BEI biological exposure index

BFU-E blood erythroid progenitor

II-xxxii

# BLL blood lead level

BLM biotic ligand m odel

BM basement mem brane

BMI body m ass index

BDNF brain-derived ne urotrophic factor

BOTMP Bruinicks-Oseretsky Test of Motor Proficiency

BP blood pressure

BPb blood lead concentration

BSA bovine serum albumin

BSI Brief Symptom Inventory

BTQ Boston Teacher Questionnaire

BUN blood urea nitrogen

bw, b. wt., BW body weight

C3H10T/12 mouse embryo cell line

C3, C4 complement proteins

CA chromosome aberration

CA3 cornu ammonis 3 region of hippocampus

45 

# Ca calcium-45 radionuclide

Ca-ATP calcium-dependent adenosine triphosphate

Ca-ATPase calcium-dependent adenosine triphosphatase

CaCO 3 

# calcium carbonate

CaEDTA calcium disodium ethylenediaminetetraacetic acid

CAL calcitonin

CaM calmodulin

Ca-Mg-ATPase calcium-magnesium-dependent adenosine triphosphatase

cAMP cyclic adenosinem onophosphate

CaNa 2 

# EDTA calcium disodium ethyl enediam inetetraacetic acid

CANTAB Cambridge Neuropsychologi ca l Testing Automated Battery

CAT catalase; Cognitive Abilities Test

CBCL Achenbach Child Behavior Checklist

CBCL-T Total Behavior Problem Score

CBL cumulative blood lead

CBLI cumulative blood lead index

CCB cytochalasin B

CCD charge-coupled device

II-xxxiii

# CCE Coordination Center for Effects

CCL carbon tetrachloride

CCS cosmic calf serum

C-CV RSA 

# coefficient of component va riance of respiratory sinus
arrhythmia

Cd cadm ium

109 

# Cd cadmium-109 radionuclide

CdU urinary cadmium

CEC cation exchange capacity

CESD, CES-D Center for Epidemio logic Studies Depression (scale)

GFAP glial fibrillary acidic protein

CFU-E colony forming unit blood-er ythroid progenitor (cell count)

CFU-GEMM colony forming unit blood- pluripotent progen itor (cell count)

CFU-GM blood granulocyte/macro phage progenitor (cell count)

cGMP cyclic guanosine-3',5'-monophosphate

ChAT choline acetyltransferase

CHD coronary heart disease

CHO Chinese hamster ovary cell line

CI confidence interval

CLE-SV competitive ligand-exchange/stripping voltammetry

CLRTAP Convention on Long-Range Transboundary of Air Pollution

CLS Cincinnati Lead Study

CMC criterion maximum concentration

CMI cell-mediated immunity

CNS central nervous system

COH cation-osmotic hemolysis

ConA concanavalin A

COR cortisol

CoTx cotreatment

COX-2 cyclooxygenase-2

CP coproporphryn

CPT current perception threshold

cr creatinine

CRAC calcium release activated calcium reflux

CREB cyclic AMP-response element binding protein

CRF chronic renal failure

II-xxxiv

# CV CRI chronic renal insufficien cy

CSF cerebrospinal fluid

CuZn-SOD copper and zinc-dependent superoxide dismutase

conduction velocity

CVLT California V erbal Learning Test

CV R-R 

# coefficient of variation of the R-R interval

CYP cytochrome (e.g., CYP1A, CYP-2A6, CYP3A4, CYP450)

CYP3a11 cytochrome P450 3a11

D D-statistic

DA dopamine; dopaminergic

dbcAMP dibutyryl cyclic ad enosine-3',5'-monophosphate

DCV distribution of conduction velocities

DEAE diethylaminoet hyl (chromatography)

DET diffusive equilibrium thin films

DEYO death of young

DFS decayed or filled surfaces, permanent teeth

dfs covariate-adjusted number of caries

DG dentate gyrus

DGT diffusive gradient thin films

DL DL-statistic

DMEM Dulbecco’s Minimal Essential Medium

DMEM/F12 Dulbecco’s Minimal Essential Medium/Ham’s F12

DMFS decayed, missing, or filled surfaces, permanent teeth

DMPS 2,3-dimercaptopropane 1-sulfonate

DMSA 2,3-dimercaptosuccinic acid

DMT Donnan membrane technique

DMTU dimethylthiourea

DNA deoxyribonucleic acid

DO distraction osteogenesis

DOC dissolved organic carbon

DOM dissolved organic carbon

DOPAc 3,4-dihydroxyphenylacetic acid

DPASV differential pulse anod ic stripping voltammetry

dp/dt rate of left ventri cular isovolumetric pressure

DPPD N

- N -diphenyl- p -phynylene-diamine

II-xxxv

# DR drinking water

DSA delayed spatial alternation

DTC diethyl dithiocarbomate complex

DTH delayed type hypersensitivity

DTPA diethylenetriaminepentaacetic acid

DTT dithiothreitol

dw dry weight

E embryonic day

E 2 

# estradiol

EBE early biological effect

EBV Epstein-Barr virus

EC European Community

EC 50 

# effect concentration fo r 50% of test population

eCB endocannabinoid

ECG electrocardiogram

Eco-SSL ecological soil screening level

EDS energy dispersive spectrometers

EDTA ethylenediaminetetraacetic acid

EEDQ N -ethoxycarbonyl-2-eth oxy-1,2-dihydroquinone

EEG electroencephalogram

EG egg

EGF epidermal growth factor

EGG effects on eggs

EGPN egg production

EKG electrocardiogram

electro electrophysiological stimulation

EM/CM experimental medium-to-control medium (ratio)

EMEM Eagle’s Minimal Essential Medium

eNOS endothelial nitr ic oxide synthase

EP erythrocyte protoporphyrin

EPA U.S. Environmental Protection Agency

Epi epinephrine

EPMA electron probe microanalysis

EPO erythropoietin

EPSC excitatory postsynaptic currents

II-xxxvi

# EPT macroinvertebrates from the Ephemeroptera (mayflies),
Plecoptera (stoneflies), and Trichoptera (caddisflies) group

ERG electroretinogram ; electroretinographic

ERL effects rang e – low

ERM effects rang e – median

EROD ethoxyresorufin- O -deethylase

ESCA electron spectroscopy for chem ical analysis

ESRD end-stag e renal disease

EST estrad iol

ESTH eggshell thinning

ET endothelein; essential tremor

ETOH ethyl alcohol

EXAFS extended X-ray absorption fine structure

EXANES extended X-ray absorp tion near edge spectroscopy

F F-statistic

F344 Fischer 344 (rat)

FAV f inal acute value

FBS fetal bovine serum

FCS f etal calf serum

FCV final chronic value

FD food

FEF forced expiratory flow

FEP free erythrocyte protoporphyrin

FERT f ertility

FEV 1 

# forced expiratory volume in one second

FGF fibroblast growth factor (e.g., β FGF, α FGF)

FI f ixed interval (operant conditioning)

FIAM free ion activity m odel

FMLP N -for myl-L-methionyl-L-l eucyl-L-phenylalanine

fMRI functional m agnetic resonance imaging

FR fixed-ratio operant conditioning

FSH f ollicle stimulating hormone

FT3 free triiodothyronine

FT4 free thyroxine

FTES free testosterone

II-xxxvii

# FTII Fagan Test of Infant Intelligence

FTPLM flow-through permeation liquid membranes

FURA-2 1-[6-amino-2-(5-carboxy- 2-oxazolyl)-5-benzofuranyloxy]-2-
(2-amino-5-methylphenoxy) ethane- N

, N

, N'

, N' -tetraacetic acid

FVC forced vital capacity

( -GT ( -glutamyl transferase

G gestational day

GABA gamma aminobutyric acid

GAG glycosaminoglycan

G12 CHV79 cells derived from the V79 cell line

GCI General Cognitive Index

GD gestational day

GDP guanosine diphosphate

GEE generalized estimating equations

GFAAS graphite furnace atomic absorption spectroscopy

GFR glomerular filtration rate

GGT ( -glutamyl transferase

GH growth hormone

GI gastrointestinal

GIME-VIP gel integrated microelect rodes combined with voltammetric
in situ profiling

GIS geographic infor mation system

GLU glutamate

GMAV genus mean acute value

GMCV genus mean chronic value

GMP guanosine monophosphate

GMPH general morphology

GnRH gonadotropin releasing hormone

GOT aspartate aminotransferase

GP gross productivity

G6PD, G6PDH glucose-6- phosphate dehydrogenase

GPEI glutathione S -transferase P enhancer element

gp91 phox 

# NAD(P)H oxidase

GPT glutamic-pyruvic transaminase

GPx glutathione peroxidase

GRO growth

II-xxxviii

# GRP78 glucose-regulated protein 78

GSD geometric standard deviation

GSH reduced glutathione

GSIM gill surface interaction model

GSSG glutathione disulfide

GST glutathione- S -transferase

GSTP placental glutathione transferase

GTP guanosine triphosphate

GV gavage

H + 

# acidity

3 

# H hydrogen-3 radionuclide (tritium)

HA humic acid; hydroxyapatite

Hb hemoglobin

HBEF Hubbard Brook Experimenatl Forest

HBSS Hank’s Balanced Salt Solution

HCG; hCG human chorionic gonadotropin

Hct hematocrit

HDL high-density lipopr otein (cholesterol)

HEP habitat evaluation procedure

HET Binghamton heterogeneous stock

HFPLM hollow fiber permeation liquid membranes

Hgb hemoglobin

HGF hepatocyte growth factor

HH hydroxylamine hydrochloride

H-H high-high

HHANES Hispanic Health and Nutrition Examination Survey

H-L high-low

HLA human leukocyte antigen

H-MEM minimum essential medium/nutrient mixture–F12-Ham

HMP hexose monophosphate shunt pathway

HNO 3 

# nitric acid

H 2 

# O 2 

# hydrogen peroxide

HOME Home Observation for Measurement of Environment

HOS TE human osteosarcoma cells

HPLC high-pressure liquid chromatography

II-xxxix

# H 3 

# PO 4 

# phosphoric acid

HPRT hypoxanthine phosphoribosyltransferase (gene)

HR heart rate

HSI habitat suitability indices

H 2 

# SO 4 

# sulfuric acid

HSPG heparan sulfate proteoglycan

Ht hematocrit

HTC hepatoma cells

hTERT catalytic subunit of human telomerase

HTN hypertension

IBL integrated blood lead index

IBL H WRAT-R integrated blood lead index H Wide Range Achievement

Test-Revised (interaction)

ICD Intern ational Classification of Diseases

ICP inductively coupled plasma

ICP-AES inductively coupled plas ma atomic emission spectroscopy

ICP-MS, ICPMS inductively coupl ed plasma mass spectrometry

ID-MS isotope dilution mass spectrometry

IFN interferon (e.g., IFN- ( )

Ig immunoglobulin (e.g., IgA, IgE, IgG, IgM)

IGF-1 insulin-like growth factor 1

IL interleukin (e.g., IL-1, IL-1 $ , IL-4, IL-6, IL-12)

ILL incipient lethal level

immuno immunohistochemical staining

IMP inosine monophosphate

iNOS inducible nitric oxide synthase

i.p., IP intraperitoneal

IPSC inhibitory postsynaptic currents

IQ intelligence quotient

IRT interresponse time

ISEL in situ end labeling

ISI interstimulus interval

i.v., IV intravenous

IVCD intraventricular conduction deficit

JV juvenile

II-xl

# KABC Kaufman Assessment Battery for Children

KTEA Kaufman Test of Educational Achievement

KXRF, K-XRF K-shell X-ray fluorescence

LA lipoic acid

LB laying bird

LC lactation

LC 50 

# lethal concentration at which 50% of exposed animals die

LC 74 

# lethal concentration at which 74% of exposed animals die

LD 50 

# lethal dose at which 50% of exposed animals die

LDH lactate dehydrogenase

LDL low-density lipoprotein (cholesterol)

L-dopa 3,4-dihydroxyphenylalanine (precursor of dopamine)

LE Long Evans (rat)

LET linear energy transfer (radiation)

LH luteinizing hormone

LHRH luteinizing hormone releasing hormone

LN lead nitrate

L-NAME L- N G 

# -nitroarginine methyl ester

LOAEL lowest-observed adverse effect level

LOEC lowest-observed-effect concentration

LOWESS locally weighted scatter plot smoother

LPO lipoperoxide

LPP lipid peroxidation potential

LPS lipopolysaccharide

LT leukotriene

LT 50 

# time to kill 50%

LTER Long-Term Ecological Research (sites)

LTP long term potentiation

LVH left ventricular hypertrophy

μPIXE microfocused particle induced X-ray emission

μSXRF microfocused synchrotron-based X-ray fluorescence

MA mature

MA-10 mouse Leydig tumor cell line

MANCOVA multivariate analysis of covariance

MAO monoamine oxidase

II-xli

# MATC maximum acceptable threshold concentration

MDA malondialdehyde

MDA-TBA malondialdehyde-thiobarbituric acid

MDCK kidney epithelial cell line

MDI Mental Development Index (score)

MDRD Modification of Diet in Renal Disease (study)

MEM Minimal Essential Medium

MG microglobulin

Mg-ATPase magnesium-dependent adenosine triphosphatase

MiADMSA monoisamyl dimercaptosuccinic acid

Mi-DMSA mi monoisoamyl dimercaptosuccinic acid

MK-801 NMDA receptor antagonist

MLR mixed lymphocyte response

MMSE Mini-Mental State Examination

MMTV murine mammary tumor virus

MN micronuclei formation

MND motor neuron disease

MNNG N -methyl- N' -nitro- N -nitrosoguanidine

MPH morphology

MRI magnetic resonance imaging

mRNA messenger ribonucleic acid

MROD methoxyresorufin- O -demethylase

MRS magnetic resonance spectroscopy

MS mass spectrometry

MSCA McCarthy Scales of Children’s Abiltities

mSQGQs mean sediment quality guideline quotients

MT metallothionein

MVV maximum voluntary ventilation

MW molecular weight (e.g., high-MW, low-MW)

N, n number of observations

N/A not available

NAAQS National Ambient Air Quality Standards

NAC N -acetyl cysteine

NAD nicotinamide adenine dinucleotide

NADH reduced nicotinamide adenine dinucleotide

II-xlii

# NADP nicotinamide adenine dinucleotide phosphate

NAD(P)H, NADPH reduced nicotinamide adenine dinucleotide phosphate

NADS nicotinamide adenine dinucleotide synthase

NAF nafenopin

NAG N -acety l- $ -D-glucosaminidase

Na-K-ATPase sodium-potassium-dep endent adenosine triphosphatase

NAWQA National W ater-Quality Assessment

NBT nitro blue tetrazolium

NCBP National Contaminant Biomonitoring Program

NCD nuclear chromatin decondensation (rate)

NCS newborn calf serum

NCTB Neurobehavioral Core Test Battery

NCV nerve conduction velocity

ND non-detectable; not detected

NDI nuclear divison index

NE norepinephrine

NES Neurobehavioral Evaluation System

NF- κ B nuclear transcription factor- κ B

NGF nerve growth factor

NHANES National Health and Nutrition Examination Survey

NIOSH National Institute for Occupational Safety and Health

NIST National Institute for Standards and Technology

NK natural kille r

NMDA N -m ethyl-D-aspartate

NMDAR N -m ethyl-D-aspartate receptor

NMR nuclear m agnetic resonance

NO nitric oxide

NO 2 

# nitrogen dioxide

NO 3 

# nitrate

NOAEC no-observed-adverse- effect concentration

NOAEL no-observed-adverse-effect level

NOEC no-observed-effect concentration

NOEL no-observed-effect level

NOM natural organic matter

NORs nucleolar organizing regions

II-xliii

# NOS nitric oxide synthase ; not otherwise specified

NO

x 

# nitrogen oxides

NP net productivity

NPSH nonprotein sulfhydryl

NR not reported

NRC National Research Council

NRK normal rat kidney

NS nonsignificant

NSAID non-steroidal anti-inflammatory agent

NT neurotrophin

NTA nitrilotriacetic ac id

O 2 

# oxygen

ODVP offspring developm ent

OH hydroxyl

7-OH-coumarin 7-hydroxy-coumarin

1,25-(OH) 2 

# -D, 1,25-(OH) 2 

# D 3 

# 1,25-dihydroxyvitamin D

24,25-(OH) 2 

# -D 3 

# 24,25-dihydroxyvitamin D

25-OH-D 3 

# 25-hydroxyvitamin D

8-OHdG 8-hydroxy-2'-deoxyguanosine

O horizon forest floor

OR odds ratio; other oral

OSWER Office of Solid Waste and Emergency Response

P, p probability value

P300 event-related potential

P450 1A1 cytochrome P450 1A1

P450 1A2 cytochrome P450 1A2

P450 CYP3a11 cytochrome P450 3a11

PAD peripheral arterial d isease

PAH polycyclic aromatic hydrocarbon

PAI-1 plasminogen activator inhibitor-1

PAR population attributable risk

Pb lead

203 

# Pb lead-203 radionuclide

204 

# Pb, 206 

# Pb, 207 

# Pb, 208 

# Pb stable isotopes of lead-204, -206, -207, -208, respectively

210 

# Pb lead-210 radionuclide

II-xliv

# Pb(Ac) 2 

# lead acetate

PbB blood lead concentration

PbCl 2 

# lead chloride

Pb(ClO 4 

# ) 2 

# lead chlorate

PBG-S porphobilinogen synthase

PBMC peripheral bl ood mononuclear cells

Pb(NO 3 

# ) 2 

# lead nitrate

PbO lead oxides (or litharge)

PBP progressive bulbar paresis

PbS galena

PbU urinary lead

PC12 pheochromocytoma cell

PCR polymerase chain reaction

PCV packed cell volume

PDE phosphodiesterase

PDGF platelet-derived growth factor

PDI Psychomotor Development Index

PEC probable effect concentration

PEF expiratory peak flow

PG prostaglandin (e.g., PGE 2 

# , PGF 2 

# ); prostate gland

PHA phytohemagglutinin A

Pi inorganic phosphate

PIXE particle induced X-ray emission

PKC protein kinase C

pl NEpi plasma norepinephrine

PMA progressive muscular atrophy

PMN polymorphonuclear leucocyte

PMR proportionate mortality ratio

PN postnatal (day)

P5N pyrimidine 5'-nucleotidase

PND postnatal day

p.o., PO per os (oral administration)

POMS Profile of Mood States

ppb parts per billion

ppm parts per million

II-xlv

# PPVT-R Peabody Picture Vocabulary Test-Revised

PRA plasma renin activity

PRL prolactin

PROG progeny counts or numbers

PRR prevalence rate ratio

PRWT progeny weight

PST percent transferrin saturation

PTH parathyroid hormone

PTHrP parathyroid hor mone-related protein

PVC polyvinyl chloride

PWM pokeweed mitogen

PRWT progeny weight

QA/QC quality assura nce/quality control

Q/V flux of air (Q) divided by volume of culture (V)

r Pearson correlation coefficient

R 2 

# multiple correlation coefficient

2 

# r correlation coefficient

226 

# Ra most stable isotope of radium

R/ALAD ratio of ALAD activity be fore and after reactivation

RAVLT Rey Auditory Verbal Learning Test

86 

# Rb rubidium-86 radionuclide

RBA relative bioavailablity

RBC red blood cell; erythrocyte

RBF renal blood flow

RBP retinol binding protein

RBPH reproductive behavior

RCPM Ravens Colored Progressive Matrices

REL rat epithelial (cells)

REP reproduction

RHIS reproductive organ histology

222 

# Rn most stable isotope of radon

RNA ribonucleic acid

ROS reactive oxygen species

ROS 17.2.8 rat osteosarcoma cell line

RPMI 1640 Roswell Park Memorial In stitute basic cell culture medium

II-xlvi

# RR

RT

RSEM

RSUC

RT

∑ SEM

SA7

SAB

SAM

SBIS-4

s.c., SC

SCAN

SCE

SCP

SD

SDH

SDS

SE

SEM

SES

sGC

SH

SHBG

SHE

SIMS

SIR

SLP

SM

SMAV

SMR

SNAP

SNP

SO 2



# SOD relative risk; rate ratio

reaction time

resorbed embryos

reproductive success (general)

reproductive tissue

sum of the molar concentrations of simultaneously extracted

metal

sim ian adenovirus

Science Advisory Board

S -adenosyl-L-methionine

Stanford-Binet Intelligence Scale-4th edition

subcutaneous

Test for Auditory Processing Disorders

selective chemical extraction; sister chromatid exchange

stripping chronopotentiometry

Spraque-Dawley (rat); standard deviation

succinic acid dehydrogenase

sodium dodecyl sulfate; Symbol Digit Substitution

standard error; standard estimation

standard error of the mean

socioeconomic status

soluble guanylate cyclase

sulfhydryl

sex hormone binding globulin

Syrian hamster embryo cell line

secondary ion mass spectrometry

standardized incidence ratio

synthetic leaching procedure

sexually mature

species mean acute value

standardized mortality ratio

Schneider Neonatal Assessment for Primates

sodium nitroprusside

sulfur dioxide

superoxide dismutase

II-xlvii

# SOPR sperm-oocyte penetration rate

SPCL sperm cell counts

SPCV sperm cell viability

SQGs sediment quality guidelines

SRA Self Reported Antisocial Behavior scale

SRD Self Report of Delinquent Behavior

SRIF somatostatin

SRM Standard Reference Material

SRT simple reaction time

SSADMF Social Security Admini stration Death Master File

SSB single-strand breaks

SSEP somatosensory-evoked potential

StAR steroidogenic acute regulatory protein

STORET STOrage and RETrieval

SVC sensory conduction velocity

SVRT simple visual reaction time

T testosterone

TA tail

TABL time-averaged blood lead

T&E threatened and endangered (species)

TAT tyrosine aminotransferase

TB tibia

TBARS thiobarbituric acid-reactive species

TBPS Total Behavior Problem Score

TCDD methionine-choline-deficient diet

T cell T lymphocyte

TCLP toxic characteristic leaching procedure

TE testes

TEC threshold effect concentration

TEDG testes degeneration

TEL tetraethyl lead

TES testosterone

TEWT testes weight

TF transferrin, translocation factor

TG 6-thioguanine

II-xlviii

# TGF transforming growth factor

TH tyrosine hydroxylase

232 

# Th stable isotope of thorium-232

TLC Treatment of Lead-exposed Children (study)

TNF tumor necrosis factor (e.g., TNF- α )

TOF time-of-flight

tPA plasminogen activator

TPRD total production

TRH thyroid releasing hormone

TRV toxicity reference value

TSH thyroid stimulating hormone

TSP triple-super phosphate

TT3 total triiodothyronine

TT4 serum total thyroxine

TTES total testosterone

TTR transthyretin

TU toxic unit

TWA time-weighted average

TX trom boxane (e.g., TXB 2 

# )

U uriniary

235 

# U, 238 

# U uranium-234 and -238 radionuclides

UCP urinary coproporphyrin

UDP uridine diphosphate

UNECE United Nations Economic Comm ission for Europe

Ur urinary

USFWS U.S. Fish and Wildlife Service

USGS United States Geological Survey

UV ultraviolet

V79 Chinese hamster lung cell line

VA Veterans Administration

VC vital capacity; vitamin C

VDR vitamin D receptor

VE vitamin E

VEP visual-evoked potential

variable-interval

II-xlix VI

# vit C vitamin C

vit E vitamin E

VMA vanilmandelic acid

VMI Visual-Motor Integration

VSM vascular smooth muscle (cells)

VSMC vascular smooth muscle cells

WAIS Wechsler Adult Intelligence Scale

WDS wavelength dispersive spectrometers

WHO World Health Organization

WISC Wechsler Intelligence Scale for Children

WISC-R Wechsler Intelligence Scale for Children-Revised

WO whole organism

WRAT-R Wide Range Achievement Test-Revised

WT wild type

WTHBF-6 human liver cell line

ww wet weight

XAFS X-ray absorption fine structure

XANES X-ray absorption near edge spectroscopy

XAS X-ray absorption spectroscopy

XPS X-ray photoelectron spectroscopy

X-rays synchrotron radiation

XRD X-ray diffraction

XRF X-ray fluorescence

ZAF correction in reference to thre e components of matrix effects:
atomic number (Z), absorpti on (A), and fluorescence (F)

ZnNa 2 

# DTPA zinc disodium diet hylenetriaminepentaacetic acid

ZnNa 2 

# EDTA zinc disodium ethyl enediaminetetraacetic acid

ZPP zinc protoporphyrin

II-l

# AX4-1 

# AX4. CHAPTER 4 ANNEX

ANNEX TABLES AX4

# AX4-2Table AX4-1. Analytical Methods for Determining Lead in Blood, Urine, and HairSampleMatrixPreparation Method Analytical MethodSampleDetection LimitAccuracy(percent recovery)ReferenceBlood Wet ashing with acid mixtures; residue dissolution indilute HClO4ASV with mercury-graphite electrode(NIOSH Method 195)40 μg/L95B105NIOSH (1977b)Blood Wet ashing with HNO3; residue dissolution in diluteHNO3GFAAS(NIOSH Method 214)100 μg/LNo data NIOSH (1977e)Blood Dilution with Triton X-100®; addition of nitric acidand diammonium phosphateGFAAS 2.4μg/L93B105Aguilera de Benzoet al. (1989)Blood Dilution of sample with ammonium solutioncontaining Triton X-100ICP/MS 15μg/L96B111Delves and Campbell(1988)Blood Dilution of sample in 0.2% Triton X-100 and water GFAAS.15 μg/L97B150Que Hee et al. (1985)ICP-MS 0.1ppb94B100Blood Wet ashing, dilutionGFAAS 4ppb90B108Zhang et al. (1997)Blood andurineMixing of urine sample with HNO3; filtration,chelation of lead in wholeblood or filtered urine withAPDC, extraction with MIBKAAS(NIOSH Method 8003)0.05 μg/g (blood);50 μg/L (urine)99 (±10.8%) NIOSH (1994)Blood andurineWet ashing of sample with HNO3, complexationwith diphenylthio-carbazone, and extraction withchloroformSpectrophotometry(NIOSH Method 102)30 μg/L (blood);12 μg/L (urine)9797NIOSH (1977a)Blood andurine206Pb addition and sample acid digestion; leadcoprecipitation by addition of Ba(NO3)2, followed byelectrodeposition onplatinum wireIDMS No data98B99Manton and Cook(1984)Blood andtissueDigestion of sample with HNO3/HClO4/H2SO4; heat ICP-AES (Method 8005) 0.01 μg/g (blood);0.2 μg/g (tissue)113 NIOSH (1984)

# AX4-3Table AX4-1 (cont’d). Analytical Methods forDetermining Lead in Blood, Urine, and HairSampleMatrixPreparation Method Analytical MethodSampleDetection LimitAccuracy(percent recovery)ReferenceBlood Addition of 50 μL of blood into reagent, mixing,and transferring to sensor strip (commercial test kit)Gold electrode sensor1.4 μg/dLNo data ESA (1998)Urine Collect 50 mL urine sample and add 5 mLconcentrated HNO3as preservative; filter samplesthrough cellulose membrane, adjust pH to 8, ash filtersand resins in low temperature oxygen plasma for6 hoursICP-AES (Method 8310) 5 μg/L100 NIOSH (1994)Serum,blood, andurineFiltration of sample if needed; blood requiresdigestion in a Parr bomb; dilution of serum or urinewith acid or waterICP-AES10B50 μg/L85 (serum) >80(urine, blood)Que Hee and Boyle(1988)Urine Wet ashing of sample with acid mixture anddissolution in dilute HClO4ASV with mercury-graphite electrode(Method 200)4 μg/L90B110NIOSH (1977c)Hair Cleaning of sample with acetone/ methanol; digestionwith acid mixture and heat; diammonium phosphateaddition as matrix modifierGFAAS0.16 μg/g99Wilhelm et al. (1989)Hair Cleaning with lauryl sulfate and water; digestion withheated nitric acidICP-AES1 μg/gNo data DiPietro et al. (1989)Hair Cleaning with water; digestion with heated nitric acidand H2O2ET-AAS<0.026 μg/g>90 Drash et al. (1997)Hair Cleaning with acetone/waterXRF0.5 μg/gNo data Gerhardsson et al.(1995a)AAS, atomic absorption spectroscopy; APDC, ammonium pyrrolidine dithiocarbamate; ASV, anode stripping voltammetry; Ba(NO3)2, barium nitrate; ET-AAS, electro-thermalatomic absorption spectrometry; GFAAS, graphite furnace atomic absorption spectroscopy; H2O2, hydrogen peroxide; H2SO4, sulfuric acid; HClO4, perchloric acid; HNO3,nitric acid; ICP-AES, inductively coupledplasma/atomic emission spectroscopy; ICP-MS, inductively coupledplasma-mass spectrometry; IDMS, isotope dilution massspectrometry; MIBK, methyl isobutyl ketone; NIOSH,National Institute for Occupational Safety and Health;206Pb, lead 206; XRF, X-ray fluorescence.

# AX4-4Table AX4-2. Summary of Selected Measurements of PbB Levels in HumansReference, StudyLocation, and PeriodStudy Description PbB Measurement CommentUnited StatesCDC (2005)U.S.1999-2002Design: National survey (NHANES IV)stratified, multistage probability cluster designSubjects: Children and adults ($1 yrs, n = 16, 915)in general populationBiomarker measured: PbBAnalysis: ICP-MSUnits: μg/dLGeometric mean (95% CI)Age (yr) 1999-2000 2001-20021-5: 1.66 (1.60, 1.72) 1.45 (1.39, 1.40)n: 7, 970 8, 9456-11: 1.51 (1.36, 1.66) 1.25 (1.14, 1.36)n: 905 1,04412-19: 1.10 (1.04, 1.17) 0.94 (0.90, 0.99)n: 2, 135 2, 231$20:1.75 (1.68, 1.81) 1.56 (1.49, 1.62)n: 4, 207 4, 772Males: 2.01 (1.93, 2.09) 1.78 (1.71, 1.86)n: 3, 913 4, 339Females: 1.37 (1.32, 1.43) 1.19 (1.14, 1.25)n: 4,057 4, 606Data from NHANES IV Phase 1(1999-2000) and 2 (2001-2002).Brody et al. (1994)Pirckle et al. (1998)U.S.1988-1994Design: National survey (NHANES III)stratified multistage probability cluster design.Subjects: Children and adults ($1 yrs, n = 29, 843)in general populationBiomarker measured: PbBAnalysis: GFAASUnits: μg/dLGeometric mean (95% CI)Age (yr) 1988-1991 1991-19941-5: 3.6 (3.3, 4.0) 2.7 (2.5, 3.0)n: 2, 234 2, 3926-11: 2.5 (2.2, 2.7) 1.9 (1.8, 2.1)n: 1, 587 1, 34512-19: 1.6 (1.4, 1.9) 1.5 (1.4, 1.7)n: 1, 376 1, 61520-49: 2.6 (2.5, 2.8) 2.1 (2.0, 2.2)n: 4, 320 4, 71650-69 4.0 (3.8, 4.2) 3.1 (2.9, 3.2)n: 2,071 2,026$704.0 (3.7, 4.3) 3.4 (3.3, 3.6)n: 1, 613 1, 548Males:3.7 (3.5, 3.9) 2.8 (2.6, 2.9)n: 6,051 6, 258Females:2.1 (2.0, 2.2) 1.9 (1.8, 2.)n: 6,068 7, 384Comparison of data from NHANES IIIPhase 1 (1988-1991) and Phase 2(1991-1994) indicated declining PbBconcentrations in children.

# AX4-5Table AX4-2 (cont’d). Summary of SelectedMeasurements of PbB Levels in HumansReference, StudyLocation, and Period Study Description PbB Measurement CommentUnited States (cont’d)Nash et al. (2003)U.S.1988-1994Design: National survey (NHANES III) stratified,multistage probability cluster designSubjects: Women(n = 2, 575), age range:40-59 yrs, in general populationBiomarker measured: PbBAnalysis: GFAASUnits: μg/dLGeometric mean (95% CI, n)Premenopausal: 1.9 (1.7, 2.0, 1, 222)Surgically menopausal: 2.7 (2.4, 3.2, 139)Naturally menopausal: 2.9 (2.5, 3.2, 653)Geometric mean PbB concentrationswere significantly lower inpremenopausal women. IncreasingPbB concentrations were significantlyassociated with decreased bone mineraldensity.Pirkle et al. (1994)U.S.1976-1980Design: National survey (NHANES II, III)stratified, multistage probability cluster designSubjects: Children and adults ($1 yrs, n = 29, 843)in general populationBiomarker measured: PbBAnalysis: GFAASUnits: μg/dLGeometric mean (95% CI)Age (yr) 1976-1980 1988-19911-5: 15.0 (14.2, 15.8) 3.6 (3.3, 4.0)n: 2, 271 2, 2346-19: 11.7 (11.2, 12.4) 1.9 (1.7, 2.2)n: 2,024 2, 96320-74: 13.1 (12.7, 13.7) 3.0 (2.8, 3.2)n: 5, 537 6, 922Males:15.0 (14.5, 15.5) 3.7 (3.5, 3.9)n: 4, 895 6,051Females:11.1 (10.6, 11.5) 2.1 (2.0, 2.2)n: 4, 937 6,068Comparison of data from NHANES II(1976-1980) and Phase 1 of NHANESIII (1988-1991) indicated decliningPbB concentrations in U.S. population.Symanski and HertzPicciotto (1995)U.S.1982-1984Design: National survey (HHANES) multistagearea probability sampleSubjects: Adults, females (n = 3, 137), age range20-60 yrs, in general Hispanic populationBiomarker measured: PbBAnalysis: GFAASUnits: μg/dLArithmetic mean (SE, n)AllPremenopausal: 7.5 (0.07, 1, 984)Menopausal: 8.9 (0.11, 1, 152)Mexican-American:Premenopausal: 7.2 (0.13, 1, 219)Menopausal: 8.4 (0.20, 624)Mean difference betweenpremenopausal and postmenopausal(#4 yrs) was 1.4 μg/dL(95% CI: 0.20, 2.7).

# AX4-6Table AX4-2 (cont’d). Summary of SelectedMeasurements of PbB Levels in HumansReference, StudyLocation, and PeriodStudy Description PbB Measurement CommentsUnited States (cont’d)Yassin et al. (2004)U.S.1988-1994Design: National survey (NHANES III) stratified,multistage probability cluster designSubjects: Adults (n = 11, 126) in generalpopulation, age range: 18-64 yr), stratified byoccupational categoryBiomarker measured: PbBAnalysis: GFAASUnits: μg/dLOccupation GM GSD Maximum nVehicle mechanics4.80 3.88 28.1 169Food service workers2.00 2.69 27.0 700Management, professionaltechnical, and sales workers 2.13 4.05 39.4 4, 768Personal service workers2.48 4.52 25.9 1, 130Agricultural workers2.76 4.02 23.4 498Production workers: machineoperators, material movers, etc. 2.88 4.24 52.9 1, 876Laborers other than in construction 3.47 3.36 21.8 137Transportation workers3.49 5.19 22.3 530Mechanics other than vehiclemechanics3.50 4.91 16.6 227Construction trades people3.66 4.64 16.9 470Construction laborers4.44 7.84 36.0 122Health service workers1.76 2.24 22.4 499All 2.426.9352.911,126MexicoHernandez-Avila et al.(2002)Mexico1993-1995Design: Cross-sectionalSubjects: Adults females (n = 903) in generalpopulation, age range: 36-70 yrBiomarker measured: PbBAnalysis: GFAASUnits:μg/dLArithmetic mean (SD, n)Premenopausal: 10.63 (5.46, 463)Menopausal: 11.39 (2.65, 437)Surgically menopausal: 10.23 (4.92, 115)Naturally menopausal: 11.30 (5.88, 322)Mean difference betweenpremenopausal and menopausal; was0.76μg/dL(95% CI: 0.224, 1.48).PbB, blood lead; GFAAS, graphite furnace atomic absorption spectroscopy; ICP-MS, inductively coupled plasma-mass spectrometry;NR, not reported.

# AX4-7Table AX4-3. Bone Lead Measurements in CadaversReference, StudyLocation, and PeriodStudy Description Lead Measurement Findings, InterpretationUnited StatesWittmers et al. (1988)Minnesota1976-82Lead in tibia, skull, iliac crest, rib,and vertebrae. 81 Caucasian malesand 53 male cadavers ranging in agefrom 0 to 98 yr. Ashing, nitric acid,AAS.Mean and SEM (μg/gbone ash) >75 yr: Tibia 29.0±3.4 (n = 28), ilium17.0±2.6 (n = 29), rib 20.5±2.4 (n = 31), vertebra 18.8±2.6 (n = 30),skull 26.1±3.2 (n = 28)51-75 yr: Tibia 24.2±2.3 (n = 38), ilium 19.2±2.4 (n = 15), rib 22.3±2.6(n = 40), vertebra 22.4±2.6 (n = 41), skull 22.8±2.9 (n = 29)36-50 yr: Tibia 16.6±4.1 (n = 14), ilium 9.9±1.6 (n = 15), rib 9.7±1.7(n = 15), vertebra 11.9±2.1 (n = 15), skull 15.2±3.3 (n = 15)21-35 yr: Tibia 5.9±1.2 (n = 18), ilium 5.3±1.2 (n = 16), rib 5.0±1.2(n = 18), vertebra 6.3±1.3 (n = 17), skull 4.9±1.1 (n = 17)14-20 yr: Tibia 2.3±1.0 (n = 13), ilium 2.3±0.9 (n = 13), rib 2.9±1.4(n = 12), vertebra 3.8±1.4 (n = 12), skull 3.2±1.7 (n = 10)0-2 yr: Tibia 0.3±0.2 (n = 11), ilium 0.0±0.0 (n = 11), rib 0.7±0.4(n = 12), vertebra 0.6±0.6 (n = 12), skull 0.6±0.4 (n = 12)Ratio of lead in tibia andskull/iliac/rib/vertebrae<1 from age 0 to 35 yrs then>1 from 36 to 75 yrs andgreater than 75 yrs. Evidenceof differential distributionamongst bones with age; theearliest difference is apparentduring adolescence whentrabecular bone of thevertebral body accumulatessignificantly more lead thanthat of the other 4 sites.Saltzman et al. (1990)Cincinnati, OH1970-7129 tissues from 55 cadavers, meanage 50 yrs. Muffle furnace ashing.Pb concentrations by dithazonemethod.Higher concentrations of Pb in tibia compared with rib and vertebrae andhigher values for males compared with females. Males (n = 46): Ribs6.70±3.96 (μg/g, wet weight), tibia 12.55±10.65, vertebrae 4.12±2.49.Females (n = 8): Ribs 3.17±0.91 (μg/g, wet weight), tibia 4.54±2.04,vertebrae 2.01±0.72.Bone Pb increased with age.Results were similar to thoseof Barry (1978) and Wittmerset al. (1988).CanadaSamuels et al. (1989)Canada1965-69Ashed vertebral bones from maleand female cadavers from threeCanadian cities. AAS method.Changes for different age ranges in Pb concentration for the period1965-1969:0-11 months: 3.98μg/g(n = 28)1-4 yrs: 10.02μg/g(n = 32)5-11 yrs: 12.91μg/g(n = 26)12-19 yrs: 7.11μg/g(n = 26)$20 yrs: 14.77μg/g(n = 25)For period 1965 to 1969levels vary over age groups(p = 0.0001) but there waslittle gender difference. Forthe period 1980 to 1998 forWinnipeg, values wereapproximately half to onethird those prevailing earlier.

# AX4-8Table AX4-3 (cont’d). Bone Lead Measurements in CadaversReference, StudyLocation, and Period Study Description Lead MeasurementFindings, InterpretationEuropeDrasch et al. (1987)Germany1983-85Bone Pb in temporalbone, cortical part ofthe mid-femur, andpelvic bone from120 female and 120male adult cadavers.AAS.Geometric means:Males: Pelvic 1.95±1.00 (μg/g, wet weight), mid-femur 4.75±2.53, temporal 6.24±3.17.Females: Pelvic 1.41±0.74 (μg/g), mid-femur 3.14±1.89, temporal 5.00±2.66.Found cortical lead >trabecular lead. Limiteddifference in Pb for youngermales and females; muchhigher Pb in bones of men>50 yr old compared withwomenAge0-1 yrs 1-6 yrs 10-20 yrs 0-20 yrsSex Male Female Male FemaleMale Female Male Femalen 9 16 9 9 18 16 39 42Temporal 0.331 0.334 0.5300.732 1.770 1.740 0.858 0.749Pelvicbone0.230 0.278 0.461 0.5220.748 0.511 0.455 0.404Mid-femur 0.333 0.327 0.6420.858 1.342 1.010 0.768 0.632Drasch and Ott (1988)Germany1984Bone Pb in temporalbone, cortical part ofthe mid femur, andpelvic bone from82 child cadavers.Nitric acid digestion,AAS.(values in μg/g wet weight)Negligible difference for 0 to1 yr olds, for pre-schoolchildren (1-6 yrs) and for10 to 20 yr olds; mean valuesfor cortical bones showedhigher Pb concentrations thantrabecular bone; mean Pb inthe mid femur and temporalbone was not statisticallydifferent for each of threeage groups.Hac et al. (1997)PolandPb in rib bone and hairfrom 59 cadavers, aged1-87 yrs. Perchloricacid digestion, AAS.Bone Pb 3.0 (±1.5) μg/g (n = 54).Small increases to age 50 yrsin rib bone. Number ofsamples for each age groupnot stated.AsiaNoda et al. (1993)Japan1976, 1981, and 198676 cadavers, age range0 to 83 yrs.Age 0 yrs (1.25 μg/g wet weight) to 59 yrs (4.5 μg/g) after which there was a decrease(~2.5 μg/g). For the age range 10-49 yrs,there was no significant difference in meanvalues of 2.8 to 3.1 μg/g.Found no significant genderdifference but levels in 1986were significantly lower thanin 1976.

# AX4-9Table AX4-4. Bone Lead Measurements in Environmentally-Exposed SubjectsReference, StudyLocation, and PeriodStudy DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pbin μg/g Bone MineralFindings, InterpretationUnited StatesKim et al. (1996)Boston, MA1989-90Examination of therelationship betweentooth Pb in children and bone Pb levelsin young adults. Members of a cohort ofyoung adults (n = 63, ~20 yr of age) werereassessed 13 yr after initial examination.Dentine Pb by anodic stripping voltammetry.Bone K-shell XRF. LOWESS smoothing,multiple linear regression.No PbB.Tibia Pb 1.3 (±4.4), patella Pb 5.4 (±8.4).Dentine Pb 13.4 (±10.7).Approximately one-third of tibia and one-fourthof patella estimates were negative values.A 10 μg/g increase in dentine Pb levels inchildhood was predictive of a 1 μg/g increasein tibia Pb levels and a 5 μg/g increase inpatella PbB levels, and a 3 μg/g increase inmean bone Pb levelsamong the young adults.They concluded that Pb exposure in early lifemay be used to predict elevated body burdenup to 13 yr later.Hu et al. (1990)Boston, MAUnknownTo evaluate if K-shell XRF can be used toassess low-level Pb burdens in 34 employees(26 males, 8 females) ranging in age from 21to 58 yr of a biomedical company with noknown history of excessive Pb exposure.Medical environmental historyquestionnaire. Multiple linear regression.18 (53%) of subjects had bone Pb levels included0 or less within the estimate of uncertainty.Highest bone Pb 21±4 μg/g bone mineral.For 16 young adults, age and year of homeconstruction had a positive but statisticallyinsignificant effect (p > 0.05) on bone Pb.K-shell XRF may be useful for assessing lowlevel Pb burdens in epidemiological studies.Hu et al. (1996)Boston, MA1991+Normative Aging Study.Subjects were middle-aged and elderly menwho had community (nonoccupational)exposures to lead.Cross-sectional. Backwards eliminationmultivariate regression models thatconsidered age, race, education, retirementstatus, measures of both current andcumulative smoking, and alcoholconsumption.47-59 yrs (n = 116): PbB 5.8 (±3.7), tibia 14.6(±8.3), patella 23.6 (±12.4)60-69 yrs (n = 360): PbB 6.3 (±4.2), tibia 21.1(±11.4), patella 30.5 (±16.9)>70 yrs (n = 243): PbB 6.5 (±4.5), tibia 27(±15.6), patella 38.8 (±23.5)Factors that remained significantly related tohigher levels of both tibiaand patella Pb werehigher age and measures of cumulativesmoking, and lower levels of education.An increase in patella Pb from the median ofthe lowest to the median of the highestquintiles (13-56 μg/g) corresponded to a risein PbB of 4.3 μg/dL. Bone Pb levelscomprised the major source ofcirculating leadin these men.Campbell et al. (2004)New YorkUnknownInvestigated the relationship between bonemineral densityand environmental Pbexposure in 35 African American children.High Pb exposure: PbB levels (mean 23.6 μg/dL;n = 19); low Pb exposure (mean 6.5 μg/dL;n = 16).Unexpectedly, they found that children withhigh Pb exposure had a significantly higherbone mineral density than children with lowPb exposure. They hypothesized that thisarises from the effect of Pb on acceleratingbone maturation by inhibition of parathyroidhormone-related peptide.

# AX4-10Table AX4-4 (cont’d). Bone Lead Measurements in Environmentally-Exposed SubjectsReference, StudyLocation, and PeriodStudy DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pbin μg/g Bone MineralFindings, InterpretationUnited States (cont’d)Rosen et al.(1989)Bronx, NYUnknownComparison of L-shell XRF measuresand EDTA provocation test in lead-toxicchildren 1-6 yr old. Eligible if PbB 25-55 μg/dL and erythrocyte protoporphyrin>35 μg/dL.Negative EDTA test results (n = 30): PbB 30±5μg/dL, tibia Pb 12±2 μg/g (range 7-52).Positive EDTA test results (n = 29): PbB 39±8μg/dL, tibia Pb 37±3 μg/g (range 7-200).From PbB and LXRF alone, 90% of Pb-toxicchildren were correctly classified as beingEDTA-positive or -negative. LXRF may becapable of replacing EDTA testing.Kosnett et al. (1994)Dickson City, PA1991Aim to determine the influence ofdemographic, exposure and medicalfactors on the bone Pb concentration ofsubjects with environmental Pb exposure.101 subjects (49 males, 52 females; aged11 to 78 yrs) recruited from 49 of 123households geographically located in asuburban residential neighborhood.Tibia. Multiple regression.Mean (SD) bone Pb12.7 (14.6).Log-transformed bone Pb highly correlated withage (r = 0.71; p#0.0001). Gender differences inlog-transformed bone Pb values wereinsignificant up until the 6thdecade.Bone Pb showed no significant change up toage 20 yr, increased with the same slope inmen and women between ages 20 and 55 yrs,and then increased at a faster rate in men olderthan 55 yrs.Rosen et al. (1993)Moosic and Throop, PA1989-91Suburban population (Throop, n = 269)exposed to unusually high emissionsduring 1963-81 from nearby batteryrecycling/secondary smelter. Moosicserved as control community.Approximately 9% children aged 5-12 yr,15% 13-17 yr, 40%≥18 yr. Soil andPbB, L-shell XRF.No significant differences in tibia Pb foundamong three age groups in Moosic or Throop.Mooaic: means 5-12 yr, 6 μg/g; 13-17 yr, 8 μg/g;$18 yr, 7 μg/gThroop: means 5-12 yr, 12±1 μg/g; 13-17 yr,15±2 μg/g;$18 yr, 12±1 μg/g.No change in bone Pb with age. Baselinevalues for bone Pb inthe environmentallyexposed population of Moosic can serve as areference baseline for contemporary bone Pblevels in similar communities in the USA.Stokes et al. (1998)Bunker Hill, ID; Spokane,WA1994Examined whether environmentalexposure to Pb during childhood wasassociated with current adverseneurobehavioral effects. K-shell XRF.Formerly exposed as children 19-30 yr(n = 238, age 19-30 yr).Referents (n = 258)Exposed group:PbB 2.9 μg/dL; tibia Pb 4.6μg/g.Referent group:PbB 1.6 μg/dL; tibia Pb 0.6 μg/g.

# AX4-11Table AX4-4 (cont’d). Bone Lead Measurements in Environmentally-Exposed SubjectsReference, StudyLocation, and PeriodStudy DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pbin μg/g Bone MineralFindings, InterpretationUnited States (cont’d)McNeill et al. (2000)Idaho and Washington1994To determine if high Pb exposure inchildhood persisted until adulthood.262 exposed subjects and 268 age andsex matched controls aged 19 – 29 yr.Tibia bone Pb, cumulative PbB index.Inverse weighted group mean data,linear regressions.Group inverse weighted mean (SEM).Males: Exposed 4.54 (0.31); controls 0.03 (0.31) μgPb/g bone mineral.Females: Exposed 5.61 (0.43); controls 1.67 (0.43)μg Pb/g bone mineral.Lead from exposure in early childhood hadpersisted in the bone matrix until adulthood.Bone Pb significantly correlated with age forexposed groups. No significant correlation inregressions for control groups with age.Exposed subjects had group bone Pb levelssignificantly higher (p < 0.005) than controlsubjects in 7 of 11 age groups. Exposedsubjects had increased current PbBconcentrations that correlated significantlywith bone Pb values. Incorporation rate of Pbinto bone 0.039 (0.003) (Fg Pb/g bonemineral)/ μg/dL yr).MexicoFarias et al. (1998)Mexico City and suburbs1995-96Examined the relation of blood andtibia bone Pb levels to Pbdeterminants in 100adolescents aged11 to 21 yr. LOWESS smoothing,multivariate regressions.Females (n = 62): PbB 6.4 (±3.2), tibia 5.5(±8.6).Males (n = 36): PbB 9.1 (±5.5), tibia 3.8 (±5.5).25 subjects had bone Pb < 0.Bone Pb accounted for 4.1% of variation in PbB.Increase in bone Pb of 21.6 μg/g was associated withan increase in PbB of 1.2 μg/dL.Predictors of bone Pb included higher trafficdensity near the home, mother's smokinghistory, and time spent outdoors. Predictorsof log-transformed PbB included bone Pblevels, male sex, use of Pb-glazed ceramics,and living in Mexico City. Bone Pbaccumulated over time constitutes a moderatesource of circulatingPb during adolescencePbB = blood lead.

# AX4-12Table AX4-5. Bone Lead Measurementsin Occupationally-Exposed SubjectsReference, StudyLocation, and PeriodStudy DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pbin μg/g Bone MineralFindings, InterpretationUnited StatesHu et al. (1994)U.S.1991Construction workers aged 23 to 67 yr(n = 19). Examination of Bone Pband PbB as predictors of bloodpressure in construction workers.Multivariate linear regression,LOWESS smoothing.PbB 8.3 (±4.0), tibia Pb 9.8 (±9.5), patella Pb13.9 (±13.6).Schwartz et al. (2000b)U.S.1995Retired organolead employees (n =543). Aim to determine influence ofPbB, chelatable Pb, and tibial Pb onsystolic and diastolic blood pressure.PbB 4.6 (±2.6), tibia Pb14.4 (±9.3).Tibia Pb was not associated with any bloodpressure measures.Popovich et al. (2005)Idaho108 former female smelter employeesand 99 referents to assess the PbBversus bone Pb relationship.Exposed: PbB 2.73 (±2.39), tibia 14.4 (±0.5)Referents: PbB 1.25 (±2.10), tibia 3.22 (±0.50)Pb concentrations in tibia and blood significantlyhigher in the exposed group. Endogenous releaserate (μg Pb per dL blood/μg Pb/g bone) inpostmenopausal women wasdouble the rate found inpremenopausal women (0.132±0.019 vs. 0.067±0.014).Higher tibia bone Pb (and PbB) wasassociated with use of estrogen (present orformer) in both the whole referent group andpostmenopausal women in the referent group.CanadaFleming et al. (1997)Canada1994Primary smelter workers, 367 activeand 14 retired.PbB in 204 workers returning after a10-mo strike ended in 1991.Cumulative PbB index, K-shellmeasures with109Cd source.Active (1975-81) median PbB 16.0, (1987-92)median PbB 8.0, tibia range 0-150, calcaneus 0-250.Retired tibia range 20-120, calcaneus 40-220.Bone Pb-cumulative PbB index slopes larger forretired compared with active workers, but notsignificant.Nonlinearities in cumulative PbB index andtibia and calcaneus Pb suggest differences inPb transfer from whole blood to bone amongsmelter employees. Contribution to PbB frombone stores at any instant in time is similar forall occupationally exposed populations, activeor retired.Age-related variations in bone turnover arenot a dominant factor in endogenous exposureof male lead workers. More rapid absorptionof Pb in calcaneus than tibia.

# AX4-13Table AX4-5 (cont’d). Bone Lead Measurements in Occupationally-Exposed SubjectsReference, StudyLocation, and Period Study DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pb in μg/g Bone Mineral Findings, InterpretationCanada (cont’d)Fleming et al. (1998)Canada1994Primary smelter.ALAD 1-1 (n = 303) and ALAD1-2, 2-2(n = 65).PbB, serum Pb, cumulative PbB index,ALAD genotype, K-shell measures with109Cd source.1-1: PbB 22.9, tibia 41.2, calcaneus 71.61-2, 2-2: PbB 25.2, tibia 42.7, calcaneus 72.3.Slopes of linear relations of bone Pb to cumulativePbB index were greater for workers homoallelic forALAD 1, indicating more efficient uptake of leadfrom blood into bone; effect most significant incalcaneus bone and for workers hired since improvedsafety measures enacted in 1977 [ALAD1-1: 0.0528±0.0028 and ALAD1-2 or 2-2: 0.0355±0.0031(p < 0.001)].Decreased transfer of PbB into bone inindividuals expressing the ALAD2 allelecontrasted with increased PbB. ALADgenotype affected lead metabolism andpotentially modified lead delivery to targetorgans including the brain but ALADgenotype did not significantly affect the netaccumulation of lead in bone.Brito et al. (2000)Canada1993-98Aims were to: (i) investigate the long-termhuman Pb metabolism by measuring thechange of Pb concentration in the tibia andcalcaneus between 1993 and 1998; and (ii)assess whether improved industrial hygienewas resulting in a slow accumulation of Pbin an exposed workforce. 101 workers in asecondary lead smelter, 51 subjects hadsimilar bone Pb measurements in 1993.Most other subjects had been hired since1993. Cumulative PbB index. Linearregressions.Repeats (n = 51)1993: Tibia 39 (±19), calcaneus 64 (±36).1998: Tibia 33 (±18), calcaneus 65 (±38).Non-repeats (n = 50)1998: Tibia 15 (±16), calcaneus 13 (±18).Tibia Pb decreased significantly (p < 0.001) in the51 subjects with repeated bone Pb measurements.Tibia Pb in 1993 and changes in cumulative PbB indexwere significant predictors of changes in tibia Pb.An overall half-life of 15 yr (95% CI: 9, 55 yr) wasestimated. Adding continuing lead exposure andrecirculation of bone lead stores to the regressionmodels produced half-life estimates of 12 and 9 yr,respectively, for release of lead from the tibia. Repeatsubjects showed no net change in calcaneus Pb after5 yr.The decrease in new exposure coupled torelease of previously stored bone Pb resultedin a significant decrease in tibia Pb in therepeat subjects. The rate of clearance of Pbfrom the tibia of 9 to 15 yr is towards themore rapid end of previous estimates. Thelack of a significant change in the calcaneusPb was surprising and if confirmed wouldhave implications for models of Pbmetabolism.

# AX4-14Table AX4-5 (cont’d). Bone Lead Measurements in Occupationally-Exposed SubjectsReference, StudyLocation, and PeriodStudy DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pbin μg/g Bone MineralFindings, InterpretationCanada (cont’d)Brito et al. (2002)Canada1994, 1999Evaluated endogenous release of Pb frombone to blood in 204 exposed subjectsresuming their duties after a 10-mo strikein a primary lead smelter in 1991. BonePb (109Cd source) measured in the tibia andcalcaneus in 1994 (Fleming et al., 1997)and 1999. A linear model used to predictthe current PbB upon the level of lead inbone. 327 subjects available on bothoccasions. Group H higher PbB andGroup L lower PbB.Group H: PbB 22.0, tibia 19.2 (n = 120)Group L: PbB 20.6, tibia 82.8 (n = 45)Group H: PbB 24.2, calcaneus 41.4 (n = 90)Group L: PbB 20.2,calcaneus 138.2 (n = 45)Structural analysis of data gave slopes for tibia(2.0, 95% CI: 1.66-2.54) and calcaneus (0.19, 95%CI: 0.16-0.23) that were significantly higher thanthose predicted by the commonly used simple linearregression method, for tibia (0.73, 95%, CI:0.58-0.88) and calcaneus (0.08, 95% CI: 0.06-0.09).Suggested that more Pb than previouslypredicted by regression analysis is releasedfrom bone to blood.EuropeSomervaille et al. (1988)EnglandK-shell measures with109Cd source ondiverse Pb workers and controlsCrystal glass (n = 87); Battery plant(n = 88); Precious metals (n = 15);Laboratory (n = 20).Cumulative PbB index.Crystal glass: PbB 48.1, tibia 31.0Battery plant: PbB 32.3, tibia 32.3Precious metals: PbB 51.4, tibia 54.8Laboratory: PbB 13.1, tibia 16.7Correlation coefficients between tibia leadand duration of employment wereconsistently higher atall three factoriesrespectively (r = 0.86, p < 0.0001; r = 0.61,p < 0.0001; r = 0.80, p < 0.0001). Strongrelation between tibia Pb and cumulativePbB index among workers in factoriesfrom which PbB histories were available.Christoffersson et al.(1984)SwedenUnknownLead smelter employeesActive (n = 75); Former plant (n = 32)Finger bone measurement with57Cosource.Active: median PbB 53.8 (15.5), mean tibia 43(<20, 122)Former: median PbB 24.9 (7.0), mean tibia 59.0(<20, 135)Increase of bone Pb with time ofemployment, no association between bonePb and current PbB in active workers, inretired workers PbB rose with increasingbone Pb.Christoffersson et al.(1986)Sweden1978-84Retired lead workers.Group 1: 7 smelter, 1 storage batterymonitored for 2-5 yr directly after end ofexposure.Group 2: 6 battery, bone Pb measured 7-13 yr after end of exposure. Finger bonemeasurement with57Co source from 4 to9 times.Group 1: mean initial bone Pb 97 (61, 131),decreasing bone Pb with time half-life 6.7 yr (3.4, 15)Group 2: mean initial bone Pb 72 (37, 96), meanhalf-life 8.2 yr (2.4,∞)Decrease of lead in bone after the end ofexposure considerably faster than estimatedearlier from various data on leadmetabolism.

# AX4-15Table AX4-5 (cont’d). Bone Lead Measurements in Occupationally-Exposed SubjectsReference, StudyLocation, and PeriodStudy DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pbin μg/g Bone MineralFindings, InterpretationEurope (cont’d)Hanninen et al. (1998)FinlandUnknownStorage battery workersGrouped into those whose PbB exceeded50μg/dL[High PbB (n = 28; 21 males)],and never [Low PbB (n = 26; 22 males)].Evaluation of neuropsychologicaldysfunction.High PbB: average PbB 39.3 (±8.3), tibia 35.3(±16.6), calcaneus 100.4 (±43.1)Low PbB: average PbB 29.0 (±6.2), tibia 19.8(±13.7), calcaneus 78.6(±62.4)No relation was found between theneuropsychological testbattery and tibialPb.Erkkilä et al. (1992)FinlandUnknownK-shell measures with109Cd source on acidbattery employees and controlsActive (n = 91); Former plant (n = 16);Office (n = 38); Laboratory (n = 26). Kshell XRF.Active: PbB 30.0 (9.5), tibia 21.1 (17), calcaneus 76.6(55.3)Former plant: PbB 12.2 (6.2), tibia 32.4 (34.9),calcaneus 73.5 (57.7)Office: PbB 6.4 (3.3), tibia7.7 (11.3), calcaneus 14.2(15.6)Laboratory: PbB 3.7 (1.7), tibia 3.5 (10.8), calcaneus1.2 (10.6)Tibia Pb concentration increasedconsistently both as a function of intensityof exposure and duration of exposure.Calcaneal Pb concentration stronglydependent on the intensity rather thanduration of exposure. Biological half-lifeof Pb in calcaneus <7-8 yr periods intowhich the duration of exposure was split.Retired workers: endogenous exposure toPb arising from skeletal burdensaccumulated over a working lifetime caneasily produce the dominant contribution tosystemic Pb concentrations onceoccupational exposure has ceased.Nilsson et al. (1991)Sweden1980sGroup A: 7 retired smelter workers and1 battery worker monitored for ~10 yr with11-17 finger bone measurements with57Co.Group B: 6 retired battery workersmonitored for up to 18.5 yr with 7-13finger bone measurements.Bone Pb values decreased over time.A mono-exponential retention model was used.Group A: estimated half-life for bone Pb was6.2-27 yr.Group B: half-life was 11-470 yr.The “shared” half-life for bone Pb was 16(CI: 12, 23) yr. These values are longerthan ones of Christoffersson et al. (1986)for the same two groups; no “background”values were subtracted in the latter case.

# AX4-16Table AX4-5 (cont’d). Bone Lead Measurements in Occupationally-Exposed SubjectsReference, StudyLocation, and PeriodStudy DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pbin μg/g Bone MineralFindings, InterpretationEurope (cont’d)Gerhardsson et al.(1993)SwedenUnknownPb smelter and truck assembly (referent)workers; Active smelter (n = 70); Retiredsmelter (n = 30); Truck assembly (n = 31);Retired truck assembly (n = 10). K-shellmeasures with109Cd source.Median values presented.Active smelter: PbB 31.9 (5.0, 47.4), tibia 13.0(!4.1, 72.8), calcaneus 48.6 (0.4, 217.8)Retired smelter: PbB 9.9 (3.3, 21), tibia 39.3(2.9, 73.4), calcaneus 100.2 (34.8, 188.9)Truck: PbB 4.1 (1.7, 12.4), tibia 3.4(!9.4, 13.3), calcaneus 12.2 (!12.7, 43.0)Retired truck: PbB 3.5 (2.2, 12.2), tibia 12.0(!6.7, 23.7), calcaneus 30.2 (!7.1, 56.7)Higher calcaneus Pb than tibia Pb in activelead workers suggested more rapidabsorption over time in this mainlytrabecular bone. Estimated biological halftimes were 16 yr in calcaneus (95% CI:11, 29 yr) and 27 yr in tibia (95% CI: 16,98 yr). Strong positive correlation betweenbone Pb and cumulative PbB index.Börjesson et al. (1997)Sweden1992Pb smelter and referent male metalworkers Active smelter (n = 71); Retiredsmelter (n = 18); Referent active (n = 27);Referent retired (n = 8). Similar cohort toGerhardsson et al. (1993). Finger bonemeasurement with57Co source.Cumulative PbB index.Median values presented.Active smelter: PbB 33.1 (8.3, 93),bone Pb 23.0 (!13, 99)Retired smelter: PbB 17.2 (8.9, 33.1),bone Pb 55 (3, 88)Active referent: PbB 3.7 (0.8, 7.0),bone Pb 3 (!21, 16)Retired referent: PbB 3.9 (3.1, 6.2),bone Pb 1.5 (!3, 12)Multiple regression analyses showed bonePb was best described by the cumulativePbB index, which explained 29% of theobserved variance (multiple r2) in bone Pbin active workers and about 39% in retiredworkers. Estimated biological half-life ofbone Pb among active lead workers was5.2 yr (95% CI: 3.3-13.0 yr).Bergdahl et al. (1998)Sweden1986Secondary Pb smelterExposed (n = 77); Referents (n = 24). Kshell measures with109Cd source.Cumulative PbB index and (calculated)plasma Pb.Exposed: PbB 35.0 (14, 57), tibia 25 (5, 193),calcaneus 52 (!20, 458)Referents: PbB 5.0 (2.9, 16). tibia 10 (!6, 36),calcaneus 11(!12, 61)Strong relationships between the tibia Pb(r2= 0.78) and calcaneus (r2= 0.80) andcumulative PbB index. Half-lives of Pb intibia 13-24 yr and calcaneus 12-19.Erfurth et al. (2001)SwedenSecondary smelterActive (n = 62); Retired (n = 15);Referents (n = 26).Evaluation of effects of Pb on theendocrine system.Finger bone measures with57Co source.Median values presented.Active: PbB 33.2 (8.3, 93.2), tibia 21 (!13, 99)Retired: PbB 18.6 (10.4, 49.7), tibia 55 (3, 88)Referents: PbB 4.1 (0.8, 6.2), tibia 2 (!21, 14)No significant associations between bonePb and pituitary and thyroid hormones,serum testosterone, gonadotropin-releasinghormone and thyroidreleasing hormone.

# AX4-17Table AX4-5 (cont’d). Bone Lead Measurements in Occupationally-Exposed SubjectsReference, StudyLocation, and PeriodStudy DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pbin μg/g Bone MineralFindings, InterpretationEurope (cont’d)Roels et al. (1995)BelgiumPb smelter and others.Active production (n = 73); Otherdepartments (n = 50). K-shell measureswith109Cd source. Cumulative PbB index.Active: PbB 42.0, tibia 66.5Others: PbB 14.5, tibia 31.4Strong relationship between bone Pb andcumulative PbB index in smelterpopulations (r = 0.80, p < 0.0001; ageexplained#9.5% of variance). Slope ofregression equation of log bone Pb versuslog cumulative PbB index showed thatdoubling of cumulative PbB indexcorresponds to doubling of bone Pb.MexicoJuarez-Perez et al.(2004)Mexico City1996-7Lithographic print shop workers; Males,n = 59, 10 females; mean age 47 yrsPlasma Pb by ultraclean ICP-MS methods.K-shell measures with109Cd source.PbB 11.9 (±5.8), tibia 27.6 (±18.1; ND-73.8),patella 46.8 (±29.3; ND-139)Statistically significant associationsbetween: plasma Pb and PbB, patella Pb,tibia Pb, age, education, use of Pb-glazedceramics but not air Pb, hand Pb or hygieneindex at work. Multiple linear regressionmodels with patella and tibia Pb as mainpredictors and adjusting for PbB andhygiene index explained 57% of variabilityin plasma Pb. Negative associationbetween plasma Pb and hygiene indexsuggest oral exposure and gastrointestinaluptake of Pb predominant source of Pbexposure in these subjects.AsiaSchwartz et al. (2001)Korea1997-99Korean Pb workers (798, 639 male,164 female) and controls (135, 124 male,1 female). Evaluation of associationsbetween PbB, tibia Pb, chelatable Pb, andneurobehavioral functions. K-shellmeasures with109Cd source.Active: PbB 32 (±15), tibia 37.2 (±40.4)Controls: PbB 5.3 (±1.8), tibia 5.8 (±7.0).After adjustment for covariates, tibia Pbwas not associated with neurobehavioraltest scores.

# AX4-18Table AX4-5 (cont’d). Bone Lead Measurements in Occupationally-Exposed SubjectsReference, StudyLocation, and PeriodStudy DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pbin μg/g Bone MineralFindings, InterpretationAsia (cont’d)Todd et al. (2001)KoreaKorean Pb workers active (n = 723),retired (n = 79), controls (n = 135).Evaluation of associations between PbB,tibia Pb, chelatable Pb.K-shell measures with109Cd source.Active: median PbB 31.7, tibia 24.4(−7.4, 337.6)Retired: median PbB 13.5, tibia 26.4(−6.7, 196.7)Controls: median PbB 5.1, tibia 5.0(−10.9, 26.6)Control women higher bone Pb than men.Job duration, body mass index, and agewere positive predictors of tibial Pb. Rateof increase in tibia Pb with age itselfincreased with increasing age. Tibial Pbstores in older subjects are less bioavailableand may contribute lessto PbB than tibialstores in younger subjects.PbB = blood lead.

# AX4-19Table AX4-6. Bone Lead Contribution to PbBReference, StudyLocation, andPeriod Study DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pbin μg/g Bone MineralFindings, InterpretationUnited StatesKorrick et al.(2002)Boston, MA1990-95Nurses’ Health Study. Cross-sectional study of 264 elderlywomen; 46-54 yr (n =80) 55-64yr (n =102), 65-74 yr (n =82).Tibia and patella Pb. Multivariatelinear regression models.46-54 yr: PbB 2.7 (SE±0.3), tibia 10.5 (±1.0), patella14.9 (±1.2)55-64 yr: PbB 3.4 (±0.2), tibia 12.7 (±0.9), patella 17.0 (±1.1)65-74 yr: PbB 3.3 (±0.3), tibia 16.4 (±0.9), patella 19.8 (±1.2).An increase from the first to the fifth quintile of tibia Pb level(19 μg/g) was associated with a 1.7 μg/dL increase in PbB(p 0.0001).Tibia and patella Pb values were significantlyand positively associatedwith PbB but onlyamong postmenopausal women who were notusing estrogens. Older age and lower paritywere associated with higher tibia Pb; only agewas associated with patella Pb. Theysuggested the observed interaction of bone Pbwith estrogen status in determining PbBsupports the hypothesis that increased boneresorption, as occurs postmenopausallybecause of decreased estrogen production,results in heightened release of bone Pb storesinto blood.Popovic et al.(2005)Bunker Hill, ID1994108 former female smelteremployees and 99 referents toassess the PbB versus bone PbrelationshipExposed: PbB 2.73 (±2.39), tibia 14.4 (±0.5)Referents: PbB 1.25 (±2.10), tibia 3.22 (±0.50)Pb concentrations in tibia and blood significantly higher in theexposed group. Endogenous releaserate (μg Pb per dL blood/μPb/g bone) in postmenopausal women was double the rate foundin premenopausal women (0.132±0.019 vs. 0.067±0.014).Higher tibia bone Pb (andPbB) was associatedwith use of estrogen (present or former) inboth the whole referent group andpostmenopausal women inthe referent group.

# AX4-20Table AX4-6 (cont’d). Bone Lead Contribution to PbBReference, StudyLocation, andPeriod Study DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pbin μg/g Bone MineralFindings, InterpretationCanadaBrito et al. (2000)Canada1993-98Aims were to: (i) investigate thelong term human Pb metabolism bymeasuring the change of Pbconcentration in the tibia andcalcaneus between 1993 and 1998;and (ii) assess whether improvedindustrial hygiene was resulting in aslow accumulation of Pb in anexposed workforce. 101 workers in asecondary lead smelter, 51 subjectshad similar bone Pb measurements in1993. Most other subjects had beenhired since 1993. Cumulative PbBindex. Linear regressions.Repeats (n = 51)1993: Tibia 39 (±19), calcaneus 64 (±36).1998: Tibia 33 (±18), calcaneus 65 (±38).Non-repeats (n = 50)1998: Tibia 15 (±16), calcaneus 13 (±18).Tibia Pb decreased significantly (p <0.001) in the 51 subjects withrepeated bone Pb measurements. Tibia Pb in 1993 and changes incumulative PbB index were significant predictors of changes intibia Pb. An overall half-life of 15 yr (95% CI: 9, 55 yr) wasestimated. Adding continuing lead exposure and recirculation ofbone lead stores to the regression models produced half-lifeestimates of 12 and 9 yr, respectively, for release of lead from thetibia. Repeat subjects showed no net change in calcaneus Pb after5 yr.The decrease in new exposure coupled torelease of previously stored bone Pb resulted ina significant decrease in tibia Pb in the repeatsubjects. The rate of clearance of Pb from thetibia of 9 to 15 yr is towards the more rapid endof previous estimates. The lack of a significantchange in the calcaneus Pb was surprising andif confirmed would have implications formodels of Pb metabolism.Brito et al. (2002)Canada1994, 1999Evaluated endogenous release of Pbfrom bone to blood in 204 exposedsubjects resuming their duties after a10-mo strike in a primary leadsmelter in 1991. Bone Pb (109Cdsource) measured in the tibia andcalcaneus in 1994 (Fleming et al.,1997) and 1999. A linear modelused to predict the current PbB uponthe level of lead in bone.327 subjects available on bothoccasions. Group H higher PbB andGroup L lower PbB.Group H: PbB 22.0, tibia 19.2 (n = 120)Group L: PbB 20.6, tibia 82.8 (n = 45)Group H: PbB 24.2, calcaneus 41.4 (n = 90)Group L: PbB 20.2,calcaneus 138.2 (n = 45)Structural analysis of data gaveslopes for tibia (2.0, 95% CI:1.66, 2.54) and calcaneus (0.19, 95% CI: 0.16, 0.23) that weresignificantly higher than those predicted by the commonly usedsimple linear regression method, for tibia (0.73, 95% CI: 0.58,0.88) and calcaneus (0.08, 95% CI: 0.06, 0.09).Suggested that more Pb than previouslypredicted by regression analysis is releasedfrom bone to blood.

# AX4-21Table AX4-6(cont’d). Bone Lead Contribution to PbBReference, StudyLocation, andPeriod Study DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pbin μg/g Bone MineralFindings, InterpretationMexicoBrown et al.(2000)Mexico City1994-5Investigated determinants of bone Pband PbB of 430 lactating Mexicanwomen during the early postpartumperiod and contribution of bone Pb toPbB. Linear regression analyses.PbB 9.5 (±4.5), tibia 10.2 (±10.1), patella 15.2 (±15.1). Older age, use of Pb glazed pottery, and higherproportion of life spent in Mexico City weremain predictors of higher tibia and patella Pb.Women in the 90th percentile for patella Pbhad an untransformed predicted mean PbB 3.6μg/dL higher than those in the 10th percentile.Téllez-Rojo et al.(2002)Mexico City1994-95Evaluated the hypothesis thatlactation stimulates Pb release frombone to blood. Cross–sectionalexamination of breastfeeding patternsand bone Pb as determinants of PbBamong 425 lactating women (meanage 24.8 ± 5.3 yr) for 7 mo afterdelivery. Bone Pb at 1 mopostpartum. Maternal blood samplesand questionnaire informationcollected at delivery and at 1, 4, and7 mo postpartum. Generalizedestimating equations.Mean PbB decreased with time postpartum: 1 mo 9.4 (±4.4),4 mo 8.9 (±4.0), 7 mo 7.9 (±3.3).Tibia 10.6 (11.6 after correctionfor negative values), patella15.3 (16.9 after correction). After adjustment for bone Pb andenvironmental exposure, women who exclusively breastfedtheir infants had PbB levels that were increased by 1.4 μg/dLand women who practiced mixed feeding had levels increasedby 1.0 μg/dL, in relation to those who had stopped lactation.A 10 μg Pb/g increment in patella and tibia bone Pb increasedPbB by 6.1% (95% CI: 4.2, 8.1) and 8.1% (95% CI: 5.2,11.1), respectively.They concluded that their results support thehypothesis that lactation is directly related tothe amount of Pb released from bone.Garrido-Latorreet al. (2003)Mexico City1995Aim was to examine the relationshipof PbB levels to menopause and bonelead levels in 232 perimenopausaland postmenopausal women fromMexico City. Measured bonemineral density in addition to bonePb. Information regardingreproductive characteristics andknown risk factors for PbB wasobtained using a standardquestionnaire by direct interview.Mean age of the population was54.7 yrs (±9.8). Linear regressionanalyses.PbB 9.2 (±4.7), tibia 14.85 (±10.1), patella 22.73 (±14.9).A change of 10 μg Pb/g bonemineral in postmenopausalsubjects was associated with an increase in PbB of 1.4 μg/dL,whereas a similar change inbone lead among premenopausalwomen was associated with an increase in PbB of 0.8 μg/dL.Found that postmenopausal women usinghormone replacement therapy had lower PbBlevels and higher tibiaand patella bone Pblevels than non-users; patella Pb explained thegreatest part of variations in PbB. Found noassociation with PbB levels and did notdescribe any relationships between bone leadand bone density.PbB = blood lead.

# AX4-22Table AX4-7. Bone Lead Studiesin Pregnant and Lactating SubjectsReference, StudyLocation, andPeriod Study DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pb in μg/g Bone Mineral Findings, InterpretationUnited StatesHu et al. (1996)Boston, MA1990Cord PbB measured in 223women, 41 bone Pb measuredat 1-4 postpartum. ANOVA.Values omitted if measurement uncertainty was >10 μg/g for tibia and15 μg/g for patella.Cord PbB 1.19 (±1.32), maternal PbB 2.9 (±2.6), tibia 4.5 (±4.0) patella 5.8(±4.5).Maternal age was the only factor marginally associated with combined bonePb (p = 0.08) but not individually with tibia or patella Pb.Umbilical cord PbB amongwomen served by this Bostonhospital declined dramaticallyfrom 1980 to 1990.Rothenberg et al(2000)Los Angeles, CA1995-98Examined bone Pb contribution toPbB in a group of 311 immigrantwomen (mean age 27.8 ±7.5 yr),99% from Latin America, duringthe 3rd trimester of pregnancy, and1 to 2 mo after delivery. Multipleregression, variance-weightedleast squares regression, structuralequation modeling.Prenatal PbB 2.2 (+4.8/!1.0, geometric mean), postnatal PbB 2.8(+4.9/!1.2) (p < 0.0001), tibia 6.7(±12.5), calcaneus 8.4 (±13.2). Varianceweighted multiple regression and structural equation models showed thatboth calcaneus and tibia Pb were directly associated with prenatal PbB butonly calcaneus Pb was associated with postnatal PbB. Increasing natural logyrs in the United States independently predicted decreasing calcaneus and3rd trimester PbB.Suggest that while someexogenous Pb sources andmodulators of PbB, such as useof Pb-glazed pottery and calciumin the diet, control Pb exposureduring and after pregnancy,endogenous Pb sources from pastexposure before immigrationcontinue to influence PbB levelsin this cohort.Rothenberg et al.(2002)Los Angeles, CA1995-2001Examined the effects of blood andbone PbB on hypertension andelevated blood pressure in the 3rdtrimester and postpartum among1,006 mostly Latina and AfroAmerican women. Multiple andlogistic regression.Returned and eligible: 3rd trimester PbB (n = 720) 1.9 (+3.6/!1.0),postpartum PbB (n = 704) 2.3 (+4.3/!1.2), tibia (n = 700) 8.0 (±11.4),calcaneus (n = 700) 10.7 (±11.9). Returned but ineligible: 3rd trimesterPbB (n = 279) 1.9 (+4.2/!0.8), postpartum PbB (n = 274) 2.3 (+4.7/!1.1),tibia (n = 263) 8.7 (±13.9), calcaneus (n = 262) 11.2 (±15.1). For each10 μg/g increase in calcaneus Pb level, the odds ratio for 3rd trimesterhypertension (systolic blood pressure$140 mmHg or diastolic bloodpressure$90 mmHg) was 1.86 (95% CI: 1.04, 3.32). In normotensivesubjects, each 10 μg/g increase in calcaneus Pb level was associated with a0.70 mmHg (95% CI: 0.04, 1.36) increase in 3rd trimester systolic bloodpressure and a 0.54 mmHg (95% CI: 0.01, 1.08) increase in diastolic bloodpressure after adjusting for postpartum hypertension, education,immigration status, current smoking, current alcohol use, parity, age, andbody mass index. Tibia bone Pb was notrelated to hypertension or elevatedblood pressure either in the 3rd trimester or postpartum, nor was calcaneusPb related to postpartum hypertension or elevated blood pressure.The authors concluded that pastPb exposure influenceshypertension and elevated bloodpressure during pregnancy andcontrolling blood pressure mayrequire reduction of Pb exposurelong before pregnancy.

# AX4-23Table AX4-7 (cont’d). Bone Lead Studies in Pregnant and Lactating SubjectsReference, StudyLocation, andPeriod Study DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pb in μg/g Bone Mineral Findings, InterpretationMexicoHernandez-Avilaet al. (1996)Mexico CityCross-sectional investigation ofthe interrelationships betweenenvironmental, dietary, andlifestyle histories, blood and bonePb levels, among 98 recentlypostpartum women. Multivariatelinear regression. Age 25.6(±6.8) yr.14-20 yr (n = 24): PbB 10.4 (±4.1), tibia 11.8 (±14.9), patella 14.1 (±13.3).21-29 yr (n = 44): PbB 10.3 (±4.8), tibia 10.7 (± 10.9), patella 17.1 (±13.4)30-43 yr (n = 27): PbB 7.8 (± 3.7), tibia 16.3 (±8.4), patella 18.1 (±12.7).A 34 μg/g increase in patella Pb (from the medians of the lowest to thehighest quartiles) was associated with an increase in PbB of 2.4 μg/dL.Significant predictors of bone Pb included years living in Mexico City,lower consumption of high calciumcontent foods, and nonuse of calciumsupplements for the patella and years living in Mexico City, older age, andlower calcium intake for tibia bone.Low consumption of milk and cheese,as compared to the highest consumption category (every day), wasassociated with an increase in tibia Pb of 9.7 μg/g.Suggest that patella bone is asignificant contributor to PbBduring lactation and thatconsumption of high calciumcontent foods may protectagainst the accumulation of Pbin one.González-Cossíoet al. (1997)Mexico CityUnknownExamined relationship of Pb levelsin cord blood and maternal bone tobirth weight. Umbilical cord andmaternal venous blood samplesand anthropometric andsociodemographic data wereobtained at delivery and 1 mopostpartum. Bone Pb at 1 mopostpartum. Multiple regression,LOWESS.Background information forcalcium supplementation studyHernandez-Avila et al. (2003).Mother-infant pairs (n = 272).Maternal PbB 8.9 (±4.1), cord PbB 7.1(±3.5), tibia 9.8 (±8.9), patella 14.2(±13.2).After adjustment for other determinantsof birth weight, tibia Pb was theonly Pb biomarker clearly related tobirth weight. The decline in birthweight associated with increments in tibia Pb was nonlinear and acceleratedat the highest tibia Pb quartile.In the upper quartile, neonates were onaverage, 156 g lighter than those in the lowest quartile.Bone-lead burden is inverselyrelated to birth weight.

# AX4-24Table AX4-7 (cont’d). Bone Lead Studies in Pregnant and Lactating SubjectsReference, StudyLocation, andPeriod Study DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pbin μg/g Bone MineralFindings, InterpretationMexico (cont’d)Brown et al. (2000)Mexico City1994-5Investigated determinants of bonePb and PbB of 430 lactatingMexican women during the earlypostpartum period andcontribution of bone Pb to PbB.Linear regression analyses.PbB 9.5 (±4.5), tibia 10.2 (±10.1), patella 15.2(±15.1). Older age, use of Pb glazedpottery, and higher proportion oflife spent in Mexico City weremain predictors of higher tibiaand patella Pb. Women in the90th percentile for patella Pb hadan untransformed predictedmean PbB 3.6 μg/dL higher thanthose in the 10th percentile.Chuang et al. (2001)Mexico City1994-95Aim to estimate the contributionof maternal whole PbB and bonePb, and environmental Pb toumbilical cord PbB (as a measureof fetal Pb exposure). Maternaland umbilical cord blood sampleswithin 12 hr of each infant'sdelivery. Structural equationmodeling.Bone Pb measured within 1 mo after delivery. PbB 8.45 (±3.94, n = 608),tibia 9.67 (±9.21, n = 603), patella 14.24 (±14.19, n = 575).Tibia and patella Pb, use of Pb glazed ceramics, and mean air Pb levelcontributed significantly to plasma Pb. An increase in patella Pb and tibiaPb was associated with increases in cord PbB of 0.65 and 0.25 μg/dL,respectively.Suggested that maternal plasmaPb varies independently frommaternal whole PbB.Contributions from endogenous(bone) and exogenous(environmental) sources wereapproximately the same.(Plasma Pb not measured).Ettinger et al. (2004)Mexico City1994-95Aim to quantify the relationbetween maternal blood and bonePb and breast-feeding statusamong 310 lactating women inMexico City, Mexico, at 1 mopostpartum. Breast milkmeasured. Multiple linearregression, LOWESS smoothing.Breastfeeding: PbB 9.3 (±4.4, n = 310), tibia 9.6 (±10.1,n = 303), patella14.5 (±14.9, n = 294).Non breastfeeding: PbB 9.3 (±4.9,n = 319), tibia 10.5 (±10.2, n = 306),patella 15.2 (±16.1, n = 289). Breast milk geometric mean 1.1 (range0.21-8.02) μg/L. Breast milk Pb significantly correlated with umbilical cordPb and maternal PbB at delivery and with maternal PbB and patella Pb at1 mo postpartum. An interquartile range increase in patella Pb (20 μg/g)was associated with a 14% increase in breast milk lead (95% CI: 5, 25%).An IQR increase in tibia Pb (12.0 μg/g) was associated with a 5% increasein breast milk lead (95% CI:!3, 14).Suggest that even among apopulation of women withrelatively high lifetime Pbexposure, breast milk Pb levelsare low, influenced both bycurrent Pb exposure and byredistribution of bone Pbaccumulated from pastenvironmental exposures.

# AX4-25Table AX4-7 (cont’d). Bone Lead Studies in Pregnant and Lactating SubjectsReference, StudyLocation, andPeriod Study DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pb in μg/g Bone Mineral Findings, InterpretationMexico (cont’d)Sanín et al. (2001)Mexico City1994-95Examined early postnatal growthin a cohort of healthy breastfednewborns in relation to maternalbone Pb burden. 329 mother-infant pairs sampled for umbilicalcord blood at birth and maternaland infant venous blood at 1 mopostpartum. Maternal evaluationsat 1 mo postpartum included Pbmeasures in blood and bone.Primary endpoints were attainedweight 1 mo of age, and weightgain from birth to 1 mo of age.Linear regression.Included in analyses (n = 329):Infant: cord PbB 6.8 (±3.9), PbB 1 mo 5.7 (±3.0)Maternal: PbB 9.7 (±5.2), tibia Pb10.1 (±10.3), patella Pb 15.2 (±15.2)Excluded from analyses (n = 276):Infant: cord PbB 6.3 (±3.0), PbB 1 mo 5.5 (±3.3)Maternal: PbB 8.8 (±3.9), tibia Pb9.75 (±10.3), patella Pb 14.2 (±17.3).Infant PbB were inversely associatedwith weight gain, with an estimateddecline of 15.1 g/μg/dL of PbB. Children who were exclusively breastfedhad significantly higher weight gains; however, this gain decreasedsignificantly with increasing levels of patella Pb. Multivariate regressionanalysis predicted a 3.6 g decrease inweight at 1 mo of age/μg Pb/g bonemineral increase in maternal patella Pb levels.The authors concluded thatmaternal Pb burden is negativelyassociated with infant attainedweight at 1 mo of age and topostnatal weight gain from birthto 1 mo of age.Gomaa et al. (2002)Mexico CityUnknownAim to compare umbilical cordPbB and maternal bone Pb asindependent predictors of infantmental development (n = 197).Prospective design. At 24 mo ofage, each infant was assessedusing the Bayley Scales of InfantDevelopment-II (SpanishVersion). Multiple linearregression.Cord PbB 6.7 (±3.4), tibia 11.5 (±11.0), patella 17.9 (±15.2). Afteradjustment for confounders, Pb levelsin umbilical cord blood and patellabone were significantly, independently,and inversely associated with theMental Development Index (MDI) scores of the Bailey Scale. In relation tothe lowest quartile of patella Pb,the 2nd, 3rd, and 4th quartiles wereassociated with 5.4-, 7.2-, and 6.5-point decrements in adjusted MDI scores.A 2-fold increase in cord PbB (e.g., from 5-10 μg/dL) was associated with a3.1-point decrement in MDI score.Suggest that higher maternalpatella bone Pb levels constitutean independent risk factor forimpaired mental development ininfants at 24 mo of age. Thiseffect is probablyattributable tomobilization of maternal bone Pbstores.

# AX4-26Table AX4-7 (cont’d). Bone Lead Studies in Pregnant and Lactating SubjectsReference, StudyLocation, andPeriod Study DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pb in μg/g Bone Mineral Findings, InterpretationMexico (cont’d)Hernandez-Avilaet al. (2002)Mexico City1994Aim to evaluate the effects ofmaternal bone Pb stores onanthropometry at birth in 223mother-infant pairs.Anthropometric data werecollected within the first 12 hrfollowing delivery. Maternalinformation was obtained 1 moafter delivery (mean age 24.4 ± 5.4yr). Transformed anthropometricmeasurements to an ordinal 5-category scale, and association ofmeasurements with other factorsevaluated with ordinal logisticregression models. CumulativeOdds Model.Cord blood 7.01 (±3.5), maternal PbB8.82 (± 4.0), tibia 10.70 (±7.58,adjusted for negative values), patella15.39 (±11.18, adjusted for negativevalues). Maternal PbB increased linearly by 0.096/μg of tibia Pb and0.078/μg patella Pb. Umbilical cord PbB increased by 0.111/μg tibia Pband 0.061/μg patella Pb. Birth lengthof newborns decreased as tibia Pblevels increased (odds ratio of 1.03/μg/g bone mineral [95% CI: 1.01,1.06]).Compared with women in thelower quintiles of the distributionof tibia Pb, those in the upperquintile had a 79% increase inrisk of having a lower birthlength newborn (OR ratio 1.79;95% CI: 1.10, 3.22). Patella Pbwas positively related to the riskof a low head circumferencescore; this score remainedunaffected by inclusion of birthweight. The increased risk was1.02/Fg Pb/g bone mineral (95%CI: 1.01, 1.04). Odds ratios didnot vary substantially after theauthors adjusted for birth weightand other important determinantsof head circumference.Téllez-Rojo et al.(2002)Mexico City1994-95Evaluated the hypothesis thatlactation stimulates Pb releasefrom bone to blood.Cross-sectional examination ofbreastfeeding patterns and bone Pbas determinants of PbB among 425lactating women (mean age 24.8±5.3 yr) for 7 mo after delivery.Bone Pb at 1 mo postpartum.Maternal blood samples andquestionnaire informationcollected at delivery and at 1, 4,and 7 mo postpartum. Generalizedestimating equations.Mean PbB decreased with time postpartum: 1 mo 9.4 (±4.4), 4 mo 8.9(±4.0), 7 mo 7.9 (±3.3).Tibia 10.6 (11.6 after correction for negative values), patella 15.3 (16.9 aftercorrection). After adjustment for bone Pb and environmental exposure,women who exclusively breastfed their infants had PbB levels that wereincreased by 1.4 μg/dL and women whopracticed mixed feeding had levelsincreased by 1.0 μg/dL, in relationto those who had stopped lactation.A 10 μg Pb/g increment in patella and tibia bone Pb increased PbB by 6.1%(95% CI: 4.2, 8.1) and 8.1% (95% CI: 5.2, 11.1), respectively.They concluded that their resultssupport the hypothesis thatlactation is directly related to theamount of Pb released frombone.

# AX4-27Table AX4-7 (cont’d). Bone Lead Studies in Pregnant and Lactating SubjectsReference, StudyLocation, andPeriod Study DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pb in μg/g Bone Mineral Findings, InterpretationMexico (cont’d)Hernandez-Avilaet al. (2002)Mexico City1994Evaluated the effects that maternalbone Pb has on anthropometry atbirth in 223 mother-infant pairs.Anthropometric data (birth length,head circumference) collectedwithin the first 12 hr followingdelivery. Maternal informationwas obtained 1 mo postpartum.Transformed anthropometricmeasurements to an ordinal 5-category scale, ordinal logistic-regression models.Participants (n = 223) Cord blood 7.01(±3.5), maternal PbB 8.82 (±4.0),tibia 9.83 (±8.9), patella 14.14 (±13.0).Nonparticipants (n = 494): Cord blood 6.75 (±3.50), PbB 8.47 (±4.19).Birth length of newborns decreased as tibia Pb levels increased. Comparedwith women in the lower quintiles of the distribution of tibia Pb, those in theupper quintile had a 79% increase in risk of having a lower birth lengthnewborn (odds ratio 1.79; 95% CI: 1.10, 3.22). The effect was attenuated–but nonetheless significant- even after adjustment for birth weight. PatellaPb was positively and significantly related to the risk of a low headcircumference score; this score remained unaffected by inclusion of birthweight.The authors estimated theincreased risk of having a lowhead-circumference score to be1.02/ μg Pb/g bone mineral (95%CI: 1.01, 1.04). Odds ratios didnot vary substantially after theauthors adjusted for birth weightand other important determinantsof head circumference.Hernandez-Avilaet al. (2003)Mexico City1994-95Tested the hypothesis that in arandomized trial of lactatingwomen a dietary calciumsupplement will lower PbB levels.Lactating women (mean age 24 yr)were randomly assigned to receiveeither calcium carbonate (1200 mgof elemental calcium daily) orplacebo in a double-blind trial.Blood samples were obtained atbaseline, and 3 and 6 mo after thetrial began. Primary endpoint waschange in maternal PbB in relationto supplement use and othercovariates with multivariategeneralized linear models forlongitudinal observations.Lactating calcium group (n = 296): PbB9.2 (±4.2), tibia 10.7 (±9.8), patella16.2 (±15.7)Lactating placebo (n = 321): PbB 9.4 (±5.0), tibia 9.6 (±10.3), patella 13.5(± 15.1)Women randomized to the calcium supplements experienced a small declinein PbB of 0.29 μg/dL (95% CI:!0.85,!0.26). The effect was moreapparent among women who were compliant with supplement use and hadhigh patella Pb of$5 μg/g. Among this subgroup, supplement use wasassociated with an estimated reduction in mean PbB of 1.16 μg/dL(95% CI:!2.08,!0.23), an overall reduction of 16.4%.Among lactating women withrelatively high Pb burden,calcium supplementation wasassociated with a modestreduction in PbB levels.

# AX4-28Table AX4-7 (cont’d). Bone Lead Studies in Pregnant and Lactating SubjectsReference, StudyLocation, andPeriod Study DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pb in μg/g Bone Mineral Findings, InterpretationMexico (cont’d)Téllez-Rojo et al.(2004)Mexico City1997-99Tested the hypotheses thatmaternal bone Pb burden isassociated with increasingmaternal whole PbB and plasmaPb over the 3 trimesters ofpregnancy and that this associationis modified by rates of maternalbone resorption. Urine wasanalyzed for cross-linked N-telopeptides (NTx) of type Icollagen, a biomarker of boneresorption. Patella and tibia Pb at1 mo postpartum. Mixed models.Participants (n = 193):PbB (μg/dL): initial 7.10 (±1.72), 1st trimester 6.47 (± 0.17), 2ndtrimester5.80 (± 0.17), 3rd trimester 6.05 (± 0.17).Plasma (μg/L): 1st trimester 0.13(±1.88), 2nd trimester 0.12 (± 1.95), 3rdtrimester 0.12 (± 1.88) (geometric means and SD)Bone Pb during pregnancy:Tibia 11.35 (±8.82, adjusted for negative values), patella 13.82 (±10.97,adjusted for negative values).Nonparticipants (n = 134):PbB 6.82 (±1.75), tibia 13.71 (±9.17, adjusted for negative values), patella11.79 (±9.75, adjusted for negative values).Found an increasing trend for plasma Pb among women with the highestbone Pb ($median level of 12.1 μg/g) but a decreasing trend among lessexposed women(below the median level). The observed increase reached itsmaximum among women with both the highest bone Pb and the highestbone resorption. In comparison with women with a low bone Pb and a highNTx level, those with a high bone Pb and a high NTx level had, on average,an 80% higher mean plasma Pb. In the cross-sectional analyses for eachtrimester of pregnancy, there wasan increasingly stronger associationbetween bone Pb and plasma Pb (log-transformed) as pregnancy progressed.An increase in patella lead of 10 μg/g would be associated with 9% (p =0.07), 24% (p < 0.01), and 25% (p < 0.01) increases in plasma Pb in the 1st,2nd, and 3rd trimesters of pregnancy, respectively. The correspondingvalues for tibia lead were 8% (p = 0.16), 19% (p < 0.01), and 13% (p =0.01), respectively. Dietary calcium intake was inversely associated withplasma lead.They concluded that the resultssupport the hypothesis of abiologic interaction betweenbone Pb burden and boneresorption. They also suggestthat as pregnancy progresses,bone Pb may be mobilizedincreasingly into plasma.

# AX4-29Table AX4-7 (cont’d). Bone Lead Studies in Pregnant and Lactating SubjectsReference, StudyLocation, andPeriod Study DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pb in μg/g Bone Mineral Findings, InterpretationMexico (cont’d)Moline et al. (2000)Morelos, Mexico1999Pilot study to assess the bodyburden of lead in 24 Mexicanwomen (age 21-34 yr) who werelactating. Demographic andreproductive characteristics ofwomen and potential sources oflead exposure were gathered by adirect interview. Multipleregression. Average time oflactation 22 (±17) months.PbB 4.6 (± 2.0, geometric mean), tibia 9.2 (±4.2), patella 14.8 (±8.0),calcaneus 11.7 (±11.2). An inverse relationship was noted between monthsof lactation and age-adjusted calcaneus lead level (p = 0.001).No association was observed between age-adjusted patella or tibia lead leveland months of lactation (p = 0.15).This pilot study provides furtherlimited evidence for thehypothesis that Pb mobilizationoccurs during lactation.PbB = blood lead.

# AX4-30Table AX4-8. Bone Lead Studies of Menopausal and Middle-aged to Elderly SubjectsReference, StudyLocation, andPeriod Study DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pb in μg/g Bone Mineral Findings, InterpretationUnited StatesHu et al. (1996)Boston, MA1991+Normative Aging Study.Subjects were middle-aged andelderly men who had community(nonoccupational) exposures to lead.Cross-sectional. Backwardselimination multivariate regressionmodels that considered age, race,education, retirement status, measuresof both current and cumulativesmoking, and alcohol consumption.47-59 yr: (n = 116): PbB 5.8 (±3.7), tibia 14.6 (±8.3),patella 23.6 (±12.4)60-69 yr: (n = 360): PbB 6.3 (±4.2), tibia 21.1(±11.4), patella 30.5 (±16.9)>70 yr: (n = 243): PbB 6.5 (±4.5), tibia 27 (±15.6),patella 38.8 (±23.5)Factors that remained significantly related to higherlevels of both tibia andpatella Pb were higher ageand measures of cumulative smoking, and lowerlevels of education. Anincrease in patella Pb fromthe median of the lowest to the median of thehighest quintiles (13-56 μg/g) corresponded to arise in PbB of 4.3 μg/dL. Bone Pb levelscomprised the major source of circulating lead inthese men.Kim et al. (1997)Boston, MA1991-95Normative Aging Study (n = 70).Aim to examine age and seculartrends in bone and PbB levels ofcommunity-exposed men aged 52-83yr. Bone and PbB levels measuredtwice, with a 3-yr interval.PbB 6.7 (±1.8), tibia 17.5 (±2.0), patella 29.1 (±1.8)3 yr later: PbB 5.1 (±1.4), tibia 17.9 (±1.7), patella22.2 (±1.8)Cross-sectional analysis of each set ofmeasurements indicated that, on average, a 1-yearolder individual would have 2.7% and 2.4-3.2%higher levels of Pb in patella and tibia,respectively. Secular trend over time wasdecreasing for patella Pb levels and stable for tibiaPb levels.Cheng et al. (1998)Boston, MA1991-95Normative Aging Study (n = 747).Aim to examine relationships ofnutritional factors to body Pb burden.Cross-sectional.Multiple regression models adjustingfor age, education level, smoking, andalcohol consumption.PbB 6.2 (± 4.1), tibia21.9 (± 13.3), patella32.0 (±19.5).Multiple regression models men in the lowest quintileof total dietary intake levels of vitamin D (includingvitamin supplements) (<179i.u./day) had mean tibiaand patella Pb levels 5.6 μg/g and 6.0 μg/g/ higherthan men with intake in the highest quintile ($589i.u./day). Higher calcium intake was associated withlower bone Pb levels, but this relation becameinsignificant when adjustment was made for vitaminD. Subjects in the lowest vitamin C intake quintile(<109 mg/day) had a mean PbB level 1.7 μg/dL higherthan men in the highest quintile ($339 mg/day), whilemen in the lowest iron intake quintile (<10.9 mg/day)had a mean PbB level 1.1 μg/dL higher than men inthe highest quintile ($23.5 mg/day).Also observed inverse associations of PbB levelswith total dietary intake of vitamin C and iron.Suggested that low dietary intake of vitamin Dmay increase Pb accumulation in bones, whilelower dietary intake of vitamin C and iron mayincrease PbB.

# AX4-31Table AX4-8 (cont’d). Bone Lead Studies ofMenopausal and Middle-aged to Elderly SubjectsReference, StudyLocation, andPeriod Study DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pb in μg/g Bone Mineral Findings, InterpretationUnited States (cont’d)Hu et al. (2001)Boston, MA1991+Normative Aging Study. Aim todetermine if ALAD polymorphism isassociated with altered levels of leadin bone and blood. Multivariatelinear regression models controllingfor age, education, smoking, alcoholingestion, and vitamin D intake.ALAD 1-1 (n = 608): PbB 6.3(±4.1), tibia 22.2(±13.9), patella 32.2 (±19.9)ALAD 1-2/2-2 (n = 118): PbB 5.7 (±4.2), tibia 21.2(±10.9), patella 30.4 (±17.2)ALAD 1- 1 genotype was associated with corticalbone lead levels that were 2.55 μg/g (95% CI: 0.05,5.05) higher than those of the variant allele carriers.No significant differencesby genotype with respectto Pb levels in trabecular bone or blood. Instratified analyses and a multivariate regressionmodel that tested for interaction, the relationshipof trabecular bone Pb to PbB appeared to besignificantly modified by ALAD genotype, withvariant allele carriers having higher PbB levels, butonly when trabecular bone Pb levels >60 μg/g.The authors suggest that the variant ALAD-2 allelemodifies lead kinetics possibly by decreasing leaduptake into cortical bone and increasing themobilization of lead from trabecular bone.Oliveira et al. (2002)Boston, MA1991-98Normative Aging Study.To determine if seasonal fluctuationsin PbB levels are related to increasedmobilization of bone Pb stores duringthe winter months. Measurements ofblood and bone Pb during the highsun exposure months of May-August(summer; n = 290); the intermediatesun exposure months of March, April,September, and October (spring/fall;n = 283); and the low sun exposuremonths of November-February(winter; n = 191).Mean PbB levels were slightly lower in summer(5.8 ± 3.4 μg/dL) compared with winter (6.6 ± 4.7μg/dL). Mean bone Pb levels were higher during thesummer than the winter months: 23.9 (±15.2) and20.3 (±11.3) μg/g respectively for the tibia and34.3 (±22.8) and 29.0 (±16.2) μg/g respectively forpatella.Found a significant interaction between season andbone Pb with bone Pb during the winter monthsexerting an almost 2-fold greater influence on PbBlevels than during the summer months. Theauthors attributed this to increased mobilization ofendogenous bone Pb stores arising potentially fromdecreased exposure to sunlight, lower levels ofactivated vitamin D and enhanced bone resorption.

# AX4-32Table AX4-8 (cont’d). Bone Lead Studies of Menopausal and Middle-aged to Elderly SubjectsReference, StudyLocation, andPeriod Study DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pb in μg/g Bone Mineral Findings, InterpretationUnited States (cont’d)Korrick et al. (2002)Boston, MA1990-95Nurses’ Health Study.Cross-sectional study of 264 elderlywomen; 46-54 yr (80) 55-64 yr (102),65-74 yr (82). Tibia and patella Pb.Multivariate linear regression models.46-54 yr: PbB 2.7 (SE±0.3), tibia 10.5 (±1.0), patella14.9 (±1.2)55-64 yr: PbB 3.4 (±0.2), tibia 12.7 (±0.9), patella17.0 (±1.1)65-74 yr: PbB 3.3 (±0.3), tibia 16.4 (±0.9), patella19.8 (±1.2).An increase from the first to the fifth quintile of tibiaPb level (19 μg/g) was associated with a 1.7 μg/dLincrease in PbB (p = 0.0001).Tibia and patella Pb valueswere significantly andpositively associated with PbB but only amongpostmenopausal women who were not usingestrogens. Older age and lower parity wereassociated with higher tibia Pb; only age wasassociated with patellaPb. They suggested theobserved interaction of bone Pb with estrogenstatus in determining PbB supports the hypothesisthat increased bone resorption, as occurspostmenopausally because of decreased estrogenproduction, results in heightened release of bone Pbstores into blood.Tsaih et al. (1999)Boston, MA1991-97Normative Aging Study.Aim to evaluate hypothesis that boneand erythrocyte Pb make independentcontributions to urine Pb excretedover 24 hour. Urine used as a proxyfor plasma Pb.Age range 53-82 yr (n = 71).Generalized additive model.PbB: 5.94 (±3.0), tibia 21.7 (±10.9), patella 31.1(±15.1), urinary Pb 5.69 (±1.9)Fg/day. Botherythrocyte Pb and bone Pb variables remainedindependently and significantly associated withurinary Pb.Finding suggests that bone influences plasma Pb ina manner that is independent of the influence oferythrocytic lead on plasma Pb. Reinforcessuperiority of bone Pb over PbB in predicting somechronic forms of toxicity may be mediated throughbone's influence on plasma Pb. Urinary lead mightbe useful as a proxy for plasma Pb.Wright et al. (2004)Boston, MA1991-97Normative Aging Study. Aim toevaluate if hemochromatosis gene(HFE) was associated with body leadburden. Tibia and patella bone Pb.DNA samples genotyped.Multivariate linear regressionanalyses.Of 730 subjects, 94 (13%) carried the C282Yvariant and 183 (25%) carried the H63D variant.In multivariate analyses that adjusted for age,smoking, and education, having an HFE variant allelewas an independent predictor of significantly lowerpatella Pb levels (p < 0.05).Suggested that HFE variants have altered kineticsof Pb accumulation after exposure and these effectsmay be mediated by alterations in Pb toxicokineticsvia iron metabolic pathways regulated by the HFEgene product and body iron stores.

# AX4-33Table AX4-8 (cont’d). Bone Lead Studies ofMenopausal and Middle-aged to Elderly SubjectsReference, StudyLocation, andPeriod Study DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pbin μg/g Bone MineralFindings, InterpretationUnited States (cont’d)Lin et al. (2004)Boston, MA1999-2000Community Lead Study. Measured PbBand bone Pb levels among minorityindividuals from Boston. Compared withearlier studies of predominantly whitesubjects, the 84 volunteers in this study(33:67 male to female ratio; 31-72 yrs ofage) had similar educational,occupational, and smoking profiles andmean blood, tibia, and patella Pb levels.LOWESS smoothing curves. Multiplelinear regression analyses to predictblood, tibia and patella Pb.<45 yr (n = 28): PbB 2.0 (±1.2), tibia 8.3 (±8.4),patella 8.9 (±14.3)46-60 yr (n = 41): PbB 2.8 (±1.7), tibia 10.8 (±11.5),patella 11.8 (±11.4)61-75 yr (n = 15): PbB 5.3 (±3.2),tibia 21.7 (±8.6),patella 30.9 (±15.7)Slopes of the univariate regressions of blood, tibia, andpatella lead versus age were 0.10 μg/dL/yr (p < 0.001),0.45 μg/g/yr (p <0.001), and 0.73 μg/g/yr (p < 0.001),respectively.Analyses of smoothing curves and regression linesfor tibia and patella Pbsuggested an inflectionpoint at 55 yr of age, with slopes for subjects≥55 yr of age that were not only steeper than thoseof younger subjects but also substantially steeperthan those observed for individuals >55 yr of age instudies of predominantly white participants.Berkowitz et al.(2004)New York1994-99Longitudinal study of 91 premenopausaland perimenopausal women aged$30 yrs of age from New York whowere undergoing surgical menopause(baseline; n 84) to determine if bone Pbvalues decrease and PbB values increaseduring menopause. Tibia Pbconcentrations measured at baseline, 6mo (70) and 18 mo (62) post surgery.Baseline: Median PbB 2.5 (0.3, 11.7), tibia 6.1(!22.2, 36.4)6 mo: PbB 3.2 (0.4, 12.0), tibia 6.8 (!14.2, 29.0)18 mo: PbB 3.1 (0.5, 9.1), tibia 5.8 (!15.4, 24.2)Marginal decline in tibia Pb values between 6 and18 mo post surgery for women who took estrogenreplacement therapy (ERT) but not for those whodid not take ERT. They concluded that there wasno substantial mobilization of Pb (from the tibia)during menopause but common ERT use may havemasked this effect, theamounts of Pb releasedwere too low to detect in blood, or the numbers ofsubjects was too small to detect an effect.Schafer et al.(2005)Baltimore, MDEvaluated the relations among PbB, tibiaPb, and homocysteine levels by crosssectional analysis among subjects in theBaltimore Memory Study, a longitudinalstudy of 1, 140 randomly selectedresidents in Baltimore, MD, aged 50-70yr and 66.0% female, 53.9% white, and41.4% black or African American.Multiple linear regression analyses.PbB 3.5 (±2.4) μg/dL, tibia 18.9 (±12.5) μg/g,homocysteine 10.0 (±4.1)Fmol/L. Tibia lead wasmodestly correlated with PbB (Pearson r = 0.12,p < 0.01) but was not associated with homocysteinelevels.Suggested that homocysteine could be amechanism that underlies the effects of lead on thecardiovascular and central nervous systems,possibly offering new targets for intervention toprevent the long-term consequences of leadexposure.

# AX4-34Table AX4-8 (cont’d). Bone Lead Studies ofMenopausal and Middle-aged to Elderly SubjectsReference, StudyLocation, andPeriod Study DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pb in μg/g Bone Mineral Findings, InterpretationUnited States (cont’d)Kosnett et al.(1994)Dickson City, PAAim to determine the influence ofdemographic, exposure and medicalfactors on the bone Pb concentration ofsubjects with environmental Pb exposure.101 subjects (49 males, 52 females; aged11 to 78 yrs) recruited from 49 of 123households geographically located in asuburban residential neighborhood.Log-transformed bone Pb highly correlated with age(r = 0.71; p#0.0001).Bone Pb showed no significant change up to age20 yr, increased with the same slope in men andwomen between ages 20 and 55 yr, and thenincreased at a faster rate in men older than 55 yr.Popovic et al.(2005)Bunker Hill, ID1994108 former female smelter employeesand 99 referents to assess the PbB versusbone Pb relationship.Exposed: PbB 2.73 (±2.39), tibia 14.4 (±0.5)Referents: PbB 1.25 (±2.10), tibia 3.22 (±0.50)Pb concentrations in tibia and blood significantlyhigher in the exposed group.Endogenous release rate(μg Pb per dL blood/ μg Pb/g bone) inpostmenopausal women was double the rate foundin premenopausal women (0.132±0.019 versus0.067±0.014).Higher tibia bone Pb (andPbB) was associatedwith use of estrogen (present or former) in both thewhole referent group and postmenopausal womenin the referent group.CanadaWebber et al.(1995)CanadaUnknownTested hypothesis that women onhormone replacement therapy shouldhave higher bone Pb content and lowerplasma Pb as hormone replacementtherapy would suppress the transfer ofendogenous Pb to the circulation.56 women, some using hormonereplacement therapy over ~4 yrs.Low dose hormone replacement therapy (n = 15):PbB 4.08 (±1.60), tibia 19.37(±8.62), calcaneus 24.02(±10.88)Moderate dose hormone replacement therapy (n = 11):PbB 5.22 (±3.36), tibia 16.80 (±11.68), calcaneus23.83 (±14.18)Calcium only (n = 22): PbB 4.6 (±1.59), tibia 11.13(±6.22), calcaneus 21.12 (±13.55)Women not taking hormones had significantlylower Pb values in cortical bone compared toall women on hormone replacement therapy(p = 0.007). Showed higher tibia Pb levels but noincrease in calcaneus Pb level or decrease in PbB.

# AX4-35Table AX4-8 (cont’d). Bone Lead Studies of Menopausal and Middle-aged to Elderly SubjectsReference, StudyLocation, andPeriod Study DescriptionLead Measurement (SD or range)PbB in μg/dL, Bone Pb in μg/g Bone Mineral Findings, InterpretationMexicoGarrido-Latorreet al. (2003)Mexico City1995Aim was to examine the relationship ofPbB levels to menopause and bone leadlevels in 232 perimenopausal andpostmenopausal women from MexicoCity. Measured bone mineral density inaddition to bone Pb. Informationregarding reproductive characteristicsand known risk factors for PbB wasobtained using a standard questionnaireby direct interview. Mean age of thepopulation was 54.7 yrs (±9.8). Linearregression analyses.PbB 9.2 (±4.7), tibia 14.85(±10.1), patella 22.73(±14.9).A change of 10 μg Pb/g bone mineral inpostmenopausal subjects was associated with anincrease in PbB of 1.4 μg/dL, whereas a similarchange in bone lead among premenopausal womenwas associated with an increase in PbB of 0.8 μg/dL.Found that postmenopausal women using hormonereplacement therapy had lower PbB levels andhigher tibia and patella bone Pb levels than non-users; patella Pb explained the greatest part ofvariations in PbB. Foundno association with PbBlevels and did not describe any relationshipsbetween bone leadand bone density.AustraliaGulson et al.(2002)Sydney, Australia2000Environmentally exposed females (n = 7)and males (n = 3) aged 44-70 yr. Treatedfor 6 mo with the bisphosphonatealendronate. PbB and isotopic ratiosmeasured by TIMS for 6 mo prior totreatment and 12 mo post-treatment.Bone mineral density and bone markersincluding NTxmeasured.Found a decrease in PbB concentrations and changingPbB isotopic composition inthe direction predictedduring treatment. Upon cessation of treatment, PbBincreased and the isotopic compositions changed.Results consistent withchanges in bone remodelingassociated with bisphosphonate use.PbB = blood lead.

# AX4-36Table AX4-9. Lead in Deciduous Teeth from Urban and Remote EnvironmentsReference, StudyLocation, and PeriodStudy Description Lead Measurement Findings, InterpretationCanadaTsuji et al. (2001)Ontario, CanadaDentine chips from schoolchildren livingin a remote area.Mean value of 9.2 μg/g dry weight (n = 61)Attributed the high values to consumption oflead contaminated game meat.EuropeTvinnereim et al.(1997)Norway1990-942,746 deciduous whole teeth. Mean 1.27 ± 1.87 μg/g of dry tooth substance Observedan ~50% reduction in leadconcentrations since the 1970s.Lyngbye et al. (1991)DenmarkIn 2,033 teeth from 1, 848 children.Geometric mean for the largest group from Arhus tobe 8.4 μg/g (wet weight) with similar values fromCopenhagen suburbs with asecondary lead smelter(9.6 μg/g) and a lead battery factory (9.9 μg/g).Concluded that automobileexhausts and indirect occupationalexposure were important sourcesfor the lead in dentine.Gil et al. (1996)Coruna, Spain220 whole deciduous and permanent teeth(one per subject).Permanent teeth showedhigher mean values(13.1 ±1.1 μg/g) than deciduous teeth (4.0 ± 1.1 μg/g)Found no gender differences.Nowak andChmielnicka (2000)PolandCompared permanent teeth from twocohorts, one from the highly pollutedKatowice district and a control town ofBeskid.In the control teeth, they observed decreases in leadfor incisors (41.8 μg/g) to canines (37.5 μg/g) tomolars (35.3 μg/g) to premolars (32.0 μg/g).However, there was no difference in the mean valuesfor the two centers: Katowice 36.5 ± 16.3 μg/g andBeskid 36.3 ± 11.5 μg/g.These values are very high compared withmost other studies.

# AX4-37Table AX4-9 (cont’d). Lead in DeciduousTeeth from Urban and Remote EnvironmentsReference, StudyLocation, and PeriodStudy Description Lead Measurement Findings, InterpretationMexicoHernandez-Guerreroet al. (2004)Mexico City100 healthy deciduous teeth collectedfrom 2 to 13 yr old children.Higher mean concentrations of lead in the 10-13 yrold group (7.7 μg/g) than in other age groups and themean concentrations were higher in girls (7.3 μg/g)than boys (6.3 μg/g).No association between pollution intensityand tooth lead.Frank et al. (1990)Alsace, MexicoCircular biopsies 500Fm in diameterpunched in the vertical sections of thecrown and cervical third of each root. Theage of the European subjects ranged from10 to 80 yrs in Europe and 12 to 29 yrs inMexico City. Energy-dispersive X-rayfluorescence method to compare lead inenamel and dentine of premolars andpermanent molars.Compared with the European values, there were~6 times higher inner coronal dentine and 7 to9 times higher pulpal root dentine concentrationsfor samples from Mexico City.The authors found no significant difference inthe relationship between traffic and mean leadvalues for enamel and dentine in the Europeancommunities but a significantly higher leadconcentration in relation to age. Thedifferences were attributed to traffic exposure.AsiaKarakaya et al. (1996)Ankara, Turkey103 whole deciduous teeth from primaryschool aged children aged 7 to 12 yrs.Significant differences in lead for urban (4.99 ± 0.46μg/g dry weight) compared with suburban children(1.69 ± 0.25 μg/g).

# AX4-38Table AX4-10. Lead in DeciduousTeeth from Polluted EnvironmentsReference, StudyLocation, and PeriodStudy Description Lead Measurement Findings, InterpretationEuropeBegerow et al. (1994)Germany1991790 children aged 6 yrs old living inurban and rural areas in western andeastern Germany. Incisors sampled.Lead levels of 1.50 to 1.74 μg/g from the western sectorand from 1.51 to 2.72 μg/g in the eastern sector.Major decrease (40-50%) since 1976.Cikrt et al. (1997)Czech RepublicCompared tooth (n = 162) and PbB levelsin children living at various distancesfrom a lead smelter.Significant difference in the mean tooth lead for childrenfrom the most contaminated zone less than 0.5 km from thesmelter (6.44 μg/g; n = 13) and those >5 km from thesmelter (1.45 μg/g; n = 36). PbB levels varied from 15.42μg Pb/100 ml (n = 6; 95% CI: 7.17, 33.17) close to thesmelter to 4.66 μg/100 ml (n = 165, 95% CI: 4.30, 5.04) atlarger distances.No descriptions ofthe teeth type wereavailable.AustraliaGulson (1996)Broken Hill, Australia36 exposed and nonexposed childrenfrom Broken Hill lead-zinc miningcommunity. Sectioned teeth into mainlyenamel (incisal section) and mainlydentine (cervical section). Lead isotoperatios and lead concentrations by TIMSwith isotope dilution.For subjects with low exposure (n = 13), leadconcentrations in the incisalsection ranged from 0.4 to 3.5μg/g with a mean and standard deviation of 1.2 ± 0.8 μg/g(n = 13). For the cervicalsections in low exposurechildren, the values ranged from 0.8 to 8.3 and mean3.7 ± 2.4 μg/g. For subjects with high exposure (n = 23),lead concentrations in the incisal section ranged from 1.0 to8.9 μg/g with a mean and standard deviation of 2.6 ± 1.8μg/g. For the cervical sections in high exposure childrenthe values ranged from 1.5 to 31.5 μg/g and mean 13.7± 8.0 μg/g.The isotopic results in dentine wereinterpreted to reflect an increased leadexposure from the lead-zinc-silverorebody during early childhood, probablyassociated with hand-to-mouth activity.Gulson et al. (2004)Lake Macquarie,Australia10 children from six houses in a primaryzinc-lead smelter community at NorthLake Macquarie, New South Wales,Australia. Sectioned deciduous teethcompared with environmental samples.Lead isotope ratios and leadconcentrations by TIMS with isotopedilution.PbB levels in the children ranged from 10 to 42 μg/dL andremained elevated for a number of years. Median leadlevel in the enamel section of the teeth was 2.3 μg/g with arange from 0.6 to 7.4 μg/g; in dentine the median value was5.3 μg/g with a range from 1.4 to 19.9 μg/g.Approximately 55 to 100% of lead couldbe derived from the smelter.PbB = blood lead.

# AX4-39Table AX4-11. Summary of Selected Measurements of Urine Lead Levels in HumansReference, StudyLocation, and PeriodStudy Description Urine Lead Measurement CommentUnited StatesCDC (2005)U.S.1999-2002Design: national survey (NHANES IV)stratified, multistage probability cluster designSubjects: children and adults ($6 yrs, n = 5140)in general populationBiomarker measured: urine leadAnalysis: ICP-MSUnits: μg/g creatinineGeometric mean (95% CI)Age (yr) 1999-2000 2001-2002$6:0.72 (0.70, 0.74) 0.64 (0.60, 0.68)n: 2465 26896-11: 1.17 (0.98, 1.41) 0.92 (0.84, 1.00)n: 340 36812-19: 0.50 (0.46, 0.54) 0.40 (0.38, 0.43)n: 719762$20:0.72 (0.68, 0.76) 0.66 (0.621, 0.70)n: 14061559Males: 0.72 (0.68, 0.76) 0.64 (0.61, 0.67)n: 12271334Females: 0.72 (0.68, 0.76) 0.64 (0.59, 0.69)n: 12381355Geometric mean PbB concentrationsin age strata ranged from 0.94 to1.51 μg/dL.Schwartz et al.(1999, 2000b)U.S.1993-1997Design: prospectiveSubjects: adult male (n = 543) former TELmanufacture workers (age range: 42-74 yrs)Biomarker measured: DMSA (10 mg/kg)-provoked urine leadAnalysis: GFAASUnits: μg/4 hrArithmetic mean (SD):$2 yr exposure: 17.1 (15.7)<2 yr exposure: 20.4 (17.9)Arithmetic mean (SD) PbB (μg/dL)was 5.0 (2.8) for workers exposed$2 yr and 2.8 (1.9) for workersexposed <2yr. PbB was strongestpredictor or DMSA-provoked urinelead.Arithmetic mean (SD) tibia lead (μg/g,XRF) was 15.6 (9.8) for workersexposed$2 yr and 12.1 (7.7) forworkers exposed <2yr.Rabinowitz et al.(1976)New YorkNRDesign: experimental studySubjects: adult (n:5) males, age range 25-53 yrs,ingested 300 μg Pb/day (~50% as204Pb) for10-210 daysBiomarker measured: urine leadAnalysis: MSUnits: μg/dayArithmetic mean (range): 36 (36-41)Arithmetic mean (range) PbB (μg/dL)was 19.4 (16.7-25.1).Blood-to-urine clearance estimate was0.19 (range 0.15-0.23) L/day (fromDiamond, 1992).

# AX4-40Table AX4-11 (cont’d). Summary of Selected Measurements of Urine Lead Levels in HumansReference, StudyLocation, and PeriodStudy Description Urine Lead Measurement CommentUnited States (cont’d)Berger et al. (1990)Ohio1983-1986Design: cross-sectional, convenience sampleSubjects: children (n = 39), age range not reported.Biomarker measured: timed urine leadAnalysis: AASUnits: μg/dayrange: 5-70PbB range was 22-55 μg/dL. Blood-tourine clearance estimate was 0.07 L/day(from Diamond, 1992).EuropeChamberlain et al.(1978)United Kingdom1975-1976Design: experimentalSubjects: adult males (n = 6), intravenous injectionof203Pb tracerBiomarker: urinary lead clearanceAnalysis: gamma spectrometer (203Pb)Units: L/dayArithmetic mean (range)Blood-to-urine: 0.09 (0.08-0.10)Plasma-to-urine: 20Brockhaus et al. (1988)Germany1982-1986Design: cross-sectionalSubjects: children (n = 184), age range 4-11 yrsresiding in 2 areas impacted by smelting operationsBiomarker measured: urine leadAnalysis: GFAASUnits: μg/g creatinineGeometric mean (GSD, range)Stolberg (n = 106): 9.6 (2.3, 0.2-43.0)Dortmund (n = 78): 6.7 (2.0, 1.6-41.0)Geometric mean PbB levels were~7 μg/dL.Koster et al. (1989)GermanyNRDesign: cross-sectionalSubjects: adult (n = 46, 40 males) hospitalworkers, age range 20-78 yr.Biomarker measured: urine leadAnalysis: GFAASUnits: μg/24 hr-1.73 m2(adult body surface area)Arithmetic mean (range): 6.8 (2.3-18.9)Arithmetic mean (range) PbB (μg/dL)was 7.6 (2.6-18.7).Blood-to-urine clearance estimate was0.15 L/day (from Diamond, 1992).AustraliaGulson et al. (2000)AustraliaDesign: longitudinalSubjects: women (n = 58) during pregnancy,age range 18-35 yrsBiomarker measured: blood-to-urine clearanceAnalysis: TIMSUnits: μg/hArithmetic mean (SD, range): 3.2 (0.8-10.2)Geometric mean: 2.7Reported blood-to-urine clearancecorresponds to ~0.08 L/day.

# AX4-41Table AX4-11 (cont’d). Summary of Selected Measurements of Urine Lead Levels in HumansReference, StudyLocation, and PeriodStudy Description Urine Lead Measurement CommentAsiaAraki et al. (1986,1990)JapanNRDesign: cross-sectionalSubjects: adult (n = 19) male, gun metal foundryworkers, age range 34-59 yr.Biomarker measured: urine leadAnalysis: AASUnits: μg/24 hrArithmetic mean (range): 94 (37-171)Arithmetic mean plasma concentrationwas 0.67 μg/dL (range 0.37-0.92).Plasma-to urine clearance estimate was22 L/day.Blood-to-urine clearance estimate was0.33 L/day (from Diamond, 1992).Lee et al. (1990)KoreaNRDesign: cross-sectionalSubjects: adults (n = 95) male workers in leadsmelting, battery manufacture, PVC-stabilizermanufacture facilities, age range: 19-64 yrs;reference subjects (n = 13), age range 22-54 yr.Biomarker measured: DMSA (10 mg/kg)-provoked urine leadAnalysis: GFAASUnits: μg/4 hrArithmetic mean (SD, range)Lead workers: 288.7 (167.7, 32.4-789)Reference: 23.7 (11.5, 10.5-43.5)Arithmetic mean (SD, range) PbBconcentration (μg/dL) was 44.6 (12.6,21.4-78.4) in lead workers and 5.9 (1.2,4.0-7.2) in reference subjects.PbB was strongest predictor or DMSA-provoked urine lead.Schwartz et al.(2000a), Lee et al.(2001)Korea1997-1999Design: Cross-sectionalSubjects: Adult lead (inorganic) workers(n = 798, 634 males), age range 18-65 yrs.Biomarker measured: MSA (10 mg/kg)-provokedurine leadAnalysis: GFAASUnits: μg/4 hrArithmetic mean (SD, range)186 (208, 4.8-2100)Arithmetic mean (SD, range) PbB(μg/dL) was 32.0 (15, 4-86). PbB wasstrongest predictor or DMSA-provokedurine lead.Arithmetic mean (SD, range) tibia lead(μg/g, XRF) was 37.1 (40.4, -7 to 338).AAS - atomic absorption spectroscopy; PbB = blood lead; ET-AAS -electro-thermal atomic absorption spectrometry; GFAAS - graphite furnace atomic absorptionspectroscopy; ICP-AES - inductively coupledplasma/atomic emission spectroscopy; ICP-MS- inductively coupled plasma-mass spectrometry; MS - mass spectrometry;NR - not reported; Pct - percentile; TEL -tetraethyl lead; TIMS - thermal ionization mass spectrometry.

# AX4-42Table AX4-12. Summary of Selected Measurements of Hair Lead Levels in HumansReference, StudyLocation, andPeriod Study Description Hair Lead Measurement CommentUnited StatesDiPietro et al.(1989)GA, SC, TX, VA1976-1980Design: Cross-sectional(random sample from NHANESII, HHANES Stands)Subjects: adults (n = 270, 200 males; age range:20-73 yrs) from general populationBiomarker measured: Hair leadAnalysis: ICP-AESUnits: μg/gGeometric mean (10-90thPct range)2.42 (<1.0-10.8)Hair lead level varied with hair treatment (e.g.,shampoo, coloring).Tuthill (1996)MANRDesign: Cross-sectionalSubjects: children (n = 277, 141 males,age range 6.5-7.5 yrs)Biomarker measured: Hair leadAnalysis: ICP-AESUnits: μg/g<0.1-0.9 : 13.5%1-1.9: 40.8%2-2.9: 25.6%3-3.9: 9.0%$4: 11.1%Study examined associations between hair leadlevels and attention-deficit behaviors.EuropeAnnesi-Maesanoet al. (2003)France1985, 1991-1992Design: cross-sectionalSubjects: mother (mean age 29 yr)-infant pairs (n:374)Biomarker measured: hair leadAnalysis: ICP-AESUnits: μg/gArithmetic mean (SD):Infant: 1.38 (1.26)Mother: 5.16 (6.08)Mean PbB concentrations were 96 μg/dL (SD 58)in mothers and 67 (SD 48) in infant cord blood.Infant hair-cord PbB correlation (Spearman, r)was 0.21 (p < 0.01).Drasch et al. (1997)Germany1993-1994Design: cross-sectionalSubjects: adults (n = 150, 75 males; age range: 16-93yrs) from general population with no known occupationalexposureBiomarker measured: hair lead (post-mortem)Analysis: ET-AASUnits: μg/gMedian (range): 0.76 (0.026-20.6)25-75thPct range: 0.45-1.48Median PbB (μg/dL) was 2.8 (range <0.9-16.1).Median temporal bone lead was 2.84 μg/g (range0.25-22.3), Hair lead correlation (Spearman r) was0.35 (p < 0.001) for blood, 0.10 (p > 0.05) fortemporal bone, and 0.16 (p > 0.05) for bodyburden.0.512 for liver (p = 0.003) and 0.57(p = 0.001) for kidney.Gerhardsson et al.(1995b)SwedenNRDesign: cross-sectionalSubjects: adult male smelter workers (n = 32) andreferents (n = 10)Biomarker measured: hair lead (post-mortem)Analysis: XRFUnits: μg/gMedian (range):Active workers: 8.0 (1.5-29,000)Retired workers: 2.6 (0.6-9.3)Reference: 2.05 (0.3-96)Based on reported a cumulative annual PbB indexof 1,374 μg/dL and average duration ofemployment of 31.4 yrs,average PbB may havebeen ~44 μg/dL in workers. Hair lead correlation(Spearman, r).

# AX-43Table AX4-12 (cont’d). Summary of Selected Measurements of Hair Lead Levels in HumansReference, StudyLocation, andPeriod Study Description Hair Lead Measurement CommentEurope (cont’d)Esteban et al.(1999)Russia1996Design: cross-sectionalSubjects: children (n = 189, 110 females; age rage1.9-10.6 yr) living in the vicinity of lead battery andleaded glass manufacture facilities.Biomarker measured: hair leadAnalysis: ICP-AESUnits: ng/gGeometric mean (range):5.4 (1-39.2)90thPct: ~15Geometric mean PbB was 8.5 μg/dL(range 3.1-35.7); log PbB = 1.44 + 0.35(log hair) + 0.24 (gender), r2= 0.20.AAS - atomic absorption spectroscopy; PbB = blood lead; ET-AAS -electro-thermal atomic absorption spectrometry; GFAAS - graphite furnace atomic absorptionspectroscopy; HHANES - Hispanic Health and Nutrition ExaminationSurvey; ICP-AES - inductively coupled plasma/atomic emission spectroscopy; ICP-MS - inductivelycoupled plasma-mass spectrometry; NR- not reported; Pct - percentile.

# AX4-44 

# REFERENCES

Abadin, H. G.; Wheeler, J. S. (1997) Guidance for risk a ssessment of exposure to lead: a site-specific, multi-media approach. In: Andrews, J. S.; Frumkin, H.; Johnson, B. L.; Mehlman, M. A.; Xintaras, C.; Bucsela, J. A.,
eds. Hazardous waste and public health: international congress on the health eff ects of hazardous waste.
Princeton, NJ: Princeton Scientific Publishing Co.; pp. 477-485. Agency for Toxic Substances and Disease Registry (ATSDR). (2005) Toxicological profile for lead [draft]. Atlanta,
GA: U.S. Department of Health and Hu man Services, Public Health Service.
Aguilera de Benzo, Z.; Fraile, R.; Carrión, N.; Loreto , D. (1989) Determination of lead in whole blood by

electrothermal atomisation atomic ab sorption spectrometry using tube and platform atomisers and dilution
with triton X-100. J. Anal. At. Spectrom. 4: 397-400. Ahlgren, L.; Lidén, K.; Mattsson, S.; Te jning, S. (1976) X-ray fluorescence analysis of lead in human skeleton in

vivo. Scand. J. Work Environ. Health 2: 82-86.
Ahmed, N.; Fleming, D. E. B.; Wilkie, D.; O'Meara, J. M. (2006) Effects of overlying soft tissue on X-ray fluorescence bone lead measurement uncertainty Radiat. Phys. Chem. 75: 1-6.
Al-Modhefer, A. J. A.; Bradbury, M. W. B.; Simons, T. J. B. (1991) Observations on the chemical nature of lead in

human blood serum. Clin. Sci. 81: 823-829. Alessio, L. (1988) Relationship between "chelatable lead" and the indicators of exposure and effect in current and
past occupational exposure. Sci. Total Environ. 71: 293-299.
Alexander, F. W.; Clayton, B. E.; Delves, H. T. (197 4) Mineral and trace-metal bala nces in children receiving normal and synthetic diets. Q. J. Med. 43: 89-111.
Anjilvel, S.; Asgharian, B. (1995) A multiple-path mode l of particle deposition in the rat lung. Fundam. Appl.

Toxicol. 28: 41-50. Annesi-Maesano, I.; Pollitt, R.; King, G.; Bousquet , J.; Hellier, G.; Sahuquillo, J.; Huel, G. (2003) In utero exposure to lead and cord blood total IgE. Is there a connection? Allergy 58: 589-594.
Araki, S.; Aono, H.; Yokoyama, K.; Mu rata, K. (1986) Filterable plasma c oncentration, glomer ular filtration, tubular balance, and renal clearance of heavy metals and organic substances in metal workers. Arch.

Environ. Health 41: 216-221.
Araki, S.; Sata, F.; Murata, K. (1990) Adjustment for ur inary flow rate: an improved approach to biological monitoring. Int. Arch. Occup. Environ. Health 62: 471-477.
Armstrong, R.; Chettle, D. R.; Scott, M. C.; Somervaille, L. J.; Pendlington, M. (1992) Repeated measurements of
tibia lead concentrations by in vivo X-ray fluorescence in occupational exposure. Br. J. Ind. Med.

49: 14-16.

Aro, A.; Amarasiriwardena, C.; Lee, M.-L.; Kim, R.; Hu, H. (2000) Validation of K x-ray fluorescence bone lead measurements by inductively coupled plasma mass spect rometry in cadaver legs. Med. Phys. 27: 119-123.
Aschengrau, A.; Beiser, A.; Bellinger, D. ; Copenhafer, D.; Weitzman, M. (1994) The impact of soil lead abatement
on urban children's blood lead levels: phase II results from the Boston lead-in-soil demonstration project.

Environ. Res. 67: 125-148.
Asgharian, B.; Ménache, M. G.; Miller, F. J. (2004) Modeling age-related particle deposition in humans. J. Aerosol.

Med. 17: 213-224.

Aufderheide, A. C.; Wittmers, L. E., Jr. (1992) Selected aspects of the spatial distribution of lead in bone.
Neurotoxicology 13: 809-819.
Aungst, B. J.; Fung, H. (1981) Kinetic characterization of in vitro lead transport across the rat small intestine. Toxicol. Appl. Pharmacol. 61: 39-47.
Aungst, B. J.; Dolce, J. A.; Fung, H. ( 1981) The effect of dose on the dispositio n of lead in rats after intravenous and
oral administration. Toxicol. Appl. Pharmacol. 61: 48-57. Azar, A.; Snee, R. D.; Habibi, K. (1975) An epidemiologic approach to commun ity air lead exposure using personal
samplers. In: Griffin, T. B.; Knelson, J. H., eds. Lead. Stuttgart, Federal Republic of Germany: Georg
Thieme Publishers; pp. 254-290. (Coulston, F.; Ko rte, F., eds. Environmental quality and safety: supplement v. 2).
Bailey, M. R.; Roy, M. (1994) Clearance of particles from the respiratory tract. In: Human respiratory tract model
for radiological protection: a report of a task group of the International Commission on Radiological Protection. Ann. ICRP 24(1-3): 301-413. (ICRP publication 66).
Bannon, D. I.; Abounader, R.; Lees, P. S. J.; Bressler, J. P. (2003) Effect of DMT1 knockdown on iron, cadmium, and lead uptake in Caco-2 cells. Am. J. Physiol. 284: C44-C50.

# AX4-45 Barltrop, D.; Meek, F. (1979) Effect of particle size on lead absorption from the gut. Arch. Environ. Health

34: 280-285. Barregård, L.; Svalander, C.; Schütz, A.; Westberg, G.; Sällsten, G.; Blohmé, I.; Mö lne, J.; Attman, P.-O.;
Haglind, P. (1999) Cadmium, mercury, and lead in kidney cortex of the general Swedish population: a
study of biopsies from living kidney donors. Environ. Health Perspect. 107: 867-871. Barry, P. S. I. (1975) A comparison of concentrations of lead in human tissues. Br. J. Ind. Med. 32: 119-139.
Barry, P. S. I. (1981) Concentrations of lead in th e tissues of children. Br. J. Ind. Med. 38: 61-71.
Barton, J. C. (1984) Active transport of lead-210 by everted segments of rat duodenum. Am. J. Physiol.

247: G193-G198. Barton, J. C. (1989) Retention of radiolead by human erythrocytes in vitro. Toxicol. Appl. Pharmacol. 99: 314-322.
Barton, J. C.; Conrad, M. E.; Nuby, S.; Harrison, L. (1978a) Effects of iron on the absorption and retention of lead.

J. Lab. Clin. Med. 92: 536-547.
Barton, J. C.; Conrad, M. E.; Harrison, L.; Nuby, S. (197 8b) Effects of calcium on the absorption and retention of

lead. J. Lab. Clin. Med. 91: 366-376.

Beck, B. D.; Mattuck, R. L.; Bowers, T. S.; Cohen, J. T. ; O'Flaherty, E. (2001) The development of a stochastic
physiologically-based pharmacokinetic model for lead. Sci. Total Environ. 274: 15-19. Becquemin, M. H.; Swift, D.L.; Bouchi khi, A.; Roy, M.; Teillac, A. (1991) Par ticle deposition and resistance in the
noses of adults and children. Eur. Resp. J. 4: 694-702.
Begerow, J.; Freier, I.; Turfeld, M.; Krämer, U.; Dunemann, L. (1994) Internal lead and cadmium exposure in 6-year-old children from western and eastern Germany. Int. Arch. Occup. Environ. Health 66: 243-248.
Bellinger, D.; Hu, H.; Titlebaum, L.; Needleman, H. L. (199 4) Attentional correlates of dentin and bone lead levels

in adolescents. Arch. Environ. Health 49: 98-105. Bennett, W. D.; Zeman, K. L.; Kang, C. W.; Schechter, M. S. (1997) Extrathoracic deposition of inhaled, coarse
particles (4.5μm) in children vs adults. In: Cherry, N. ; Ogden, T., eds. Inhaled particles VIII: proceedings
of an international symposium on inhaled particles organised by the British Occupational Hygiene Society; August 1996. Ann. Occup. Hyg. 41(suppl. 1): 497-502.
Bergdahl, I. A.; Skerfving, S. (1997) Partition of circulating lead between plasma and red cells does not seem to be

different for internal and external sources of lead [letter]. Am. J. Ind. Med. 32: 317-318. Bergdahl, I. A.; Schütz, A.; Grubb, A. (1996) Application of liquid chromatography-inductively coupled plasma
mass spectrometry to the study of protein-bond lead in human erythrocytes. J. Anal. Atom. Spectrom.

11: 735-738. Bergdahl, I. A.; Schütz, A.; Gerhardsson, L.; Jensen, A.; Skerfving, S. (1997a) Lead concentrations in human
plasma, urine and whole blood. Scand. J. Work Environ. Health 23: 359-363. Bergdahl, I. A.; Grubb, A.; Schütz, A.; Desnick, R. J.; Wetm ur, J. G.; Sassa, S.; Skerfving, S. (1997b) Lead binding

to δ -aminolevulinic acid dehydratase (ALAD) in human erythrocytes. Pharmacol. Toxicol. 81: 153-158.
Bergdahl, I. A.; Sheveleva, M.; Schütz, A.; Artamonova, V. G.; Skerfving, S. (1998) Plasma and blood lead in humans: capacity-limited binding to δ -aminolevulinic acid dehydratase an d other lead-binding components.

Toxicol. Sci. 46: 247-253.
Bergdahl, I. A.; Vahter, M.; Counter, S. A.; Schütz, A.; Buchanan, L. H.; Or tega, F.; Laurell, G.; Skerfving, S. (1999) Lead in plasma and whole blood from lead-exposed children. Environ. Res. 80: 25-33.
Berger, O. G.; Gregg, D. J.; Succop, P. A. (1990) Using unstimulated urinary lead excretion to assess the need for
chelation in the treatment of lead poisoning. J. Pediatr. 116: 46-51. Berkowitz, G. S.; Wolff, M. S.; Lapinski, R. H.; Todd, A. C. (2004) Prospective study of blood and tibia lead in
women undergoing surgical menopause. Environ. Health Perspect. 112: 1673-1678.
Bert, J. L.; van Dusen, L. J.; Grace, J. R. (1989) A generalized model for the prediction lead body burdens. Environ.

Res. 48: 117-127. Biagini, G.; Caudarella, R.; Vangelista, A. (1977) Renal mo rphological and functional modification in chronic lead
poisoning. In: Brown, S. S., ed. Clinical chemistry and chemical toxicology of metals. New York, NY: Elsevier/North-Holland Biomedical Press; pp. 123-126.
Blake, K. C. H.; Mann, M. (1983) Effect of calcium and phosphorus on the ga strointestinal absorption of 203Pb in

man. Environ. Res. 30: 188-194.

Blake, K. H. C.; Barbezat, G. O.; Mann , M. (1983) Effect of dietary constitue nts on the gastrointestinal absorption

of 203 

# Pb in man. Environ. Res. 30: 182-187. Bolanowska, W.; Piotrowski, J.; Garczynski, H. (1967) Triethyllead in the biological material in cases of acute
tetraethyllead poisoning. Arch. Toxicol. 22: 278-282.

# AX4-46 Booker, D. V.; Chamberlain, A. C.; Newton, D.; Stott, A. N. B. (1969) Uptake of radioactive lead following
inhalation and injection. Br. J. Radiol. 42: 457-466. Börjesson, J.; Gerhardsson, L.; Schütz, A.; Mattsson, S.; Sk erfving, S.; Österberg, K. (1997) In vivo measurements

of lead in fingerbone in active and retired lead sme lters. Int. Arch. Occup. Environ. Health 69: 97-105.
Bornschein, R. L.; Succop, P.; Dietrich, K. N.; Clark, C. S.; Que Hee, S. Hammond PB. (1985a) The influence of social and environmental factors on dust lead, hand lead, and blood lead levels in young children. Environ.

Res. 38: 108-118. Bornschein, R. L.; Hammond, P. B.; Dietrich, K. N.; Succop, P.; Krafft, K.; Clark, S.; Berger, O.; Pearson, D.; Que Hee, S. (1985b) The Cincinnati prospective study of low-level lead exposure and its effects on child
development: protocol and status report. Environ. Res. 38: 4-18.
Bos, A. J. J.; Van der Stap, C. C. A. H.; Valkovic, V.; Vis, R. D.; Verheul, H. (1985) Incorporation routes of elements into human hair: implications for hair analysis used for monitoring. Sci.Total Environ.

42: 157-169. Bowers, T. S.; Mattuck, R. L. (2001) Further comparisons of empirical and epidemiological data with predictions of
the Integrated Exposure Uptake Biokinetic Model for lead in children. Hum. Ecol. Risk Assess.

7: 1699-1713.
Bowers, T. S.; Beck, B. D.; Karam, H. S. (1994) Assessing the relationship between environmental lead

concentrations and adult blood lead levels. Risk Anal. 14: 183-189.
Bress, W. C.; Bidanset, J. H. (1991) Percutaneous in vivo and in vitro absorption of lead. Vet. Hum. Toxicol.

33: 212-214.

Brito, J. A.; McNeill, F. E.; Chettle, D. R.; Webber, C. E.; Vaillancourt, C. (2000) Study of the relationships

between bone lead levels and its variation with time and the cumulative blood lead index, in a repeated bone lead survey. J. Environ. Monit. 2: 271-276.

Brito, J. A. A.; McNeill, F. E.; Stronach, I.; Webber, C. E.; Wells, S.; Richard, N.; Chettle, D. R. (2001)
Longitudinal changes in bone lead concentration: implications for modelling of human bone lead

metabolism. J. Environ. Monit. 3: 343-351.

Brito, J. A. A.; McNeill, F. E.; Webb er, C. E.; Wells, S.; Richard, N.; Ca rvalho, M. L.; Chettle, D. R. (2002)
Evaluation of a novel structural model to describe the endogenous release of lead from bone. J. Environ.

Monit. 4: 194-201.
Brockhaus, A.; Collet, W.; Dolgner, R.; Engelke, R.; Ewers, U.; Freier, I.; Je rmann, E.; Kramer, U.; Manojlovic, N.;
Turfeld, M.; Winneke, G. (1988) Exposure to lead and cadmium of children living in different areas of north-west Germany: results of biological monitoring studies 1982-1986. Int. Arch. Occup. Environ. Health

60: 211-222. Brody, D. J.; Pirkle, J. L.; Kramer, R. A.; Flegal, K. M.; Matte, T. D.; Gu nter, E. W.; Paschal, D. C. (1994) Blood
lead levels in the U.S. population: phase 1 of the third National Health and Nutrition Examination Survey
(NHANES III, 1988 to 1991). JAMA J. Am. Med. Assoc. 272: 277-283.
Brown, A.; Tompsett, S. L. (1945) Po isoning due to mobilization of lead from the skeleton by leukaemic
hyperplasia of bone marrow. Br. Med. J. 2: 764-765.

Brown, M. J.; Hu, H.; Gonzales-Cossio, T.; Peterson, K. E.; Sanin, L.-H.; de Luz Kageyama, M.; Palazuelos, E.;
Aro, A.; Schnaas, L.; Hernandez-Avila, M. (2000) Dete rminants of bone and blood lead concentrations in
the early postpartum period. Occup. Environ. Med. 57: 535-541.

Brown, J. S.; Wilson, W. E.; Grant, L. D. (2005) Dosimetric comparisons of particle deposition. Inhalation Toxicol.

17: 355-385.

Cake, K. M.; Bowins, R. J.; Vaillancourt, C.; Gordon, C. L.; McNutt, R. H.; Laporte, R.; Webber, C. E.;
Chettle, D. R. (1996) Partition of circulating lead betw een serum and red ce lls is different for internal and

external sources of lead. Am. J. Ind. Med. 29: 440-445.
Campbell, J. R.; Toribara, T. Y. (2001) Hair-root lead to screen for lead toxicity . J. Trace Elem. Exp. Med.

14: 69-72. Campbell, B. C.; Meredith, P. A.; Moor e, M. R.; Watson, W. S. (1984) Kinetics of lead following intravenous

administration in man. Toxicol. Lett. 21: 231-235.
Campbell, J. R.; Rosier, R. N.; Novotny, L.; Puzas, J. E. (2004) The association between environmental lead exposure and bone density in children. Environ. Health Perspect. 112: 1200-1203.
Carbone, R.; Laforgia, N.; Crollo, E.; Mautone, A.; Iolasc on, A. (1998) Maternal and neonatal lead exposure in southern Italy. Biol. Neonate 73: 362-366.
Carlisle, J. C.; Wade, M. J. (1992) Predicting blood lead concentrations from environmental concentrations. Regul.

Toxicol. Pharmacol. 16: 280-289.

# AX4-47 Carroll, R. J.; Galindo, C. D. (1998) Measurement er ror, biases, and the validation of complex models for blood lead
levels in children. Environ. Health Perspect. Suppl. 106: 1535-1539. Casteel, S. W.; Cowart, R. P.; Weis, C. P.; Henningsen, G. M.; Hoffman, E.; Brattin, W. J.; Guzman, R. E.;
Starost, M. F.; Payne, J. T.; Stockham, S. L.; B ecker, S. V.; Drexler, J. W.; Turk, J. R. (1997)
Bioavailability of lead to juvenile swine dosed with soil from the Smuggl er Mountain NPL site of Aspen, Colorado. Fundam. Appl. Toxicol. 36: 177-187.
Casteel, S. W.; Weis, C. P.; Henningsen, G. M.; Brattin, W. L. (200 6) Estimation of relative bioavailability of lead
in soil and soil-like materials using young swine. Environ. Health Perspect.: 10.1289/ehp.8852.

Cavalleri, A.; Minoia, C.; Pozzoli, L.; Ba ruffini, A. (1978) Determination of plasma lead levels in normal subject
and in lead-exposed workers. Br. J. Ind. Med. 35: 21-25.
Centers for Disease Control and Prevention. (2005) Third national report on human exposure to environmental chemicals. Atlanta, GA: U.S. Department of Health and Human Services, National Center for

Environmental Health. NCEH Pub. No. 05-0570.

Chamberlain, A. C.; Heard, M. J.; Little, P.; Newton, D.; We lls, A. C.; Wiffin, R. D. (1978) Investigations into lead
from motor vehicles. Harwell, United Kingdom: United Kingdom Atomic Energy Authority; report no.

AERE-R9198. Cheng, Y.; Willett, W. C.; Schwartz, J. ; Sparrow, D.; Weiss, S.; Hu, H. (1998) Relation of nutrition to bone lead and
blood lead levels in middle-aged to elderly men. The Normative Aging Study. Am. J. Epidemiol.

147: 1162-1174. Cheng, Y.; Schwartz, J.; Spar row, D.; Aro, A.; Weiss, S. T.; Hu, H. (2 001) Bone lead and blood lead levels in
relation to baseline blood pressure and the prospective development of hypertension: the Normative Aging
Study. Am. J. Epidemiol. 153: 164-171.
Chettle, D. R.; Scott, M. C.; Somervaille, L. J. (1991) Lead in bone: sampling and quantitation using K X-rays
excited by 109 

# Cd. Environ. Health Perspect. 91: 49-55.
Chettle, D. R.; Arnold, M. L.; Aro, A. C. A.; Fleming, D. E. B.; Kondrashov, V. S.; McNe ill, F. E.; Moshier, E. L.; Nie, H.; Rothenberg, S. J.; Stronach, I. M.; Todd, A. C. (2003) An agreed statement on calculating lead
concentration and uncertainty in XRF in vivo bone lead analysis. Appl. Radiat. Isot. 58: 603-605.

Chisolm, J. J., Jr.; Mellits, E. D.; Barrett, M. B. (1976) Interrelationships among blood lead concentration, quantitative daily ALA-U and urinary lead output fo llowing calcium EDTA. In: Nordberg, G. F., ed.
Proceedings of third meeting of the subcommittee on the toxicology of metals under the Permanent
Commission and International Association on Occupational Health; November 1974; Toyko, Japan. Amsterdam, The Netherlands: Elsevier Publishing Co.; pp. 416-433.
Chisolm, J. J., Jr.; Mellits, E. D.; Quaskey, S. A. (1985) The relationship between the level of lead absorption in children and the age, type, and condition of housing. Environ. Res. 38: 31-45.
Christoffersson, J. O.; Schütz, A.; Ahlgren, L.; Haeger-A ronsen, B.; Mattsson, S.; Skerfving, S. (1984) Lead in
finger-bone analysed in vivo in active and retired lead workers. Am. J. Ind. Med. 6: 447-457. Christoffersson, J. O.; Ahlgren, L.; Schwartz, A.; Skerfving, S.; Mattsson, S. (1986) Decreas e of skeletal lead levels
in man after end of occupational exposure. Arch. Environ. Health 41: 312-318.
Chuang, H. Y.; Schwartz, J.; Gonzales-Cossio, T. ; Lugo, M. C.; Palazuelos, E.; Aro, A.; Hu, H.;
Hernandez-Avila, M. (2001) Interrelations of lead levels in bone, venous blood, and umbilical cord blood
with exogenous lead exposure through maternal plasma lead in peripartum women. Environ. Health
Perspect. 109: 527-532. Cikrt, M.; Smerhovsky, Z.; Blaha, K.; Nerudova, J.; Sediva, V.; Fornuskova, H.; Knotkova, J.; Roth, Z.; Kodl, M.;
Fitzgerald, E. (1997) Biological mon itoring of child lead exposure in the Czech Republic. Environ. Health
Perspect. 105: 406-411. Clark, S.; Bornschein, R.; Succop, P.; Peace, B.; Ryan, J.; Kochanowski, A. (1988) The Cincinnati soil-lead
abatement demonstration project. In: Davies, B. E.; Wixs on, B. G., eds. Lead in soil: issues and guidelines.
Northwood, England: Science Review Limited; pp. 287-300. Environ. Geochem. Health 9(suppl.). (Monograph series 4).
Clark, S.; Bornschein, R.; Succop, P.; Roda, S.; Peace, B. (1991) Urban lead exposures of children in Cincinnati,
Ohio. Chem. Speciation Bioavailability 3(3-4): 163-171.

Clark, S.; Bornschein, R. L.; Pan, W.; Menrath, W.; Roda, S.; Grote, J. (1996) The relationship between surface dust
lead loadings on carpets and the blood lead of young children. Environ. Geochem. Health 18: 143-146. Cools, A.; Salle, H. J. A.; Verberk, M. M.; Zielhuis, R. L. (1976) Biochemical response of male volunteers ingesting
inorganic lead for 49 days. Int. Arch. Occup. Environ. Health 38: 129-139.

# AX4-48 Cramer, K.; Goyer, R. A.; Jagenburg, R. ; Wilson, M. H. (1974) Renal ultrastr ucture, renal function, and parameters
of lead toxicity in workers with different periods of lead exposure. Br. J. Ind. Med. 31: 113-127. Cristy, M. (1981) Active bone marrow distribution as a function of age in humans. Phys. Med. Biol. 26: 389-400.
Davis, A.; Ruby, M. V.; Bergstrom, P. D. (1994) Factors controlling lead bioavailability in the Butte mining district,

Montana, USA. Environ. Geochem. Health 16: 147-157. DeSilva, P. E. (1981) Determination of lead in plasma and studies on its relationship to lead in erythrocytes. Br. J.

Ind. Med. 38: 209-217.
Delves, H. T.; Campbell, M. J. (1988) Measurements of total lead concentrations and of lead isotope ratios in whole blood by use of inductively coupled plasma source mass spectrometry. J. Anal. At. Spectrom. 3: 343-348.
DiPietro, E. S.; Philips, D. L.; Paschla, D. C.; Neese, J. W. (1989) Determination of trace elements in human hair.

Biol. Trace Elem. Res. 22: 83-100. Diamond, G. L. (1988) Biological monitoring of urine for exposure to toxic metals. In: Clarkson, T. W.;
Nordberg, G.; Sager, P., eds. Scientific basis and practical applications of biological monitoring of toxic metals. New York, NY: Plenum Press; pp. 515-529.
Diamond, G. L. (1992) Review of default value for lead plasma-to-urine transfer coefficient (TPLUR) in the U.S.
EPA uptake/biokinetic model. Syracuse, NY: Syracuse Research Corporation. Prepared for Environmental Criteria and Assessment Office, U.S. Environmental Protection Agency.
Dietrich, K. N.; Berger, O. G.; Succop, P. A. (1993) Lead exposure and the motor developmental status of urban sixyear-old children in the Cincinnati prospective study. Pediatrics 91: 301-307. Drasch, G. A.; Ott, J. (1988) Lead in human bones: investigations on an occupationally non-exposed population in
southern Bavaria (FRG), II. children. Sci. Total Environ. 68: 61-69.
Drasch, G. A.; Bohm, J.; Baur, C. (1987) Lead in human bones. Investigations on an occupationally non-exposed population in southern Bavaria (F. R. G.). I. Adults. Sci. Total Environ. 64: 303-315.
Drasch, G.; Wanghofer, E.; Roider, G. (1997) Are blood, urine, hair, and muscle valid biomonitors for the internal
burden of men with the heavy metals mercury, lead and cadmium? Trace Elem. Electrolytes 14: 116-123.
DuVal, G.; Fowler, B. A. (1989) Pre liminary purification and characterization studies of a low molecular weight,
high affinity cytosolic lead-binding protein in rat brain. Biochem. Biophys. Res. Commun. 159: 177-184.
Durbin, P. W. (1992) Distribution of transuranic elements in bone. Neurotoxicology 13: 821-824.
Eaton, D. L.; Stacey, N. H.; Wong, K.-L.; Klaassen, C. D. (1980) Dose-response effects of various metal ions on rat
liver metallothionein, glutathione, heme oxygenase, and cytochrome P -450. Toxicol. Appl. Pharmacol.

55: 393-402.

Erfurth, E. M.; Gerhardsson, L.; Nilsso n, A.; Rylander, L.; Schütz, A.; Skerfvin g, S.; Börjesson, J. (2001) Effects of
lead on the endocrine system in lead smelter workers. Arch. Environ. Health 56: 449-455. Erkkilä, J.; Armstrong, R.; Riihimaki, V.; Chettle, D. R. ; Paakkari, A.; Scott, M.; Somervaille, L.; Stark, J.;
Kock, B.; Aitio, A. (1992) In vivo measurements of lead in bone at four anatomical sites: long term
occcupational and consequent edogenous expos ure. Br. J. Ind. Med. 49: 631-644.
ESA Biosciences, Inc. (1998) LeadCa re® childhood blood lead testing. Ch elmsford, MA: ESA Biosciences, Inc.
Esteban, E.; Rubin, C. H.; Jones, R. L.; Noonan, G. (1999) Hair and blood substrates for screening children for lead
poisoning. Arch. Environ. Health 54: 436-440. Ettinger, A. S.; Téllez-Rojo, M. M.; Am arasiriwardena, C.; González-Cossío, T. ; Peterson, K. E.; Aro, A.; Hu, H.;
Hernández-Avila, M. (2004) Levels of lead in breast milk and their relation to maternal blood and bone
lead levels at one month postpartum. Environ. Health Perspect. 112: 926-931.
Ewers, U.; Stiller-Winkler, R.; Idel, H. (1982) Serum im munoglobulin, complement C3, and salivary IgA levels in

lead workers. Environ. Res. 29: 351-357.

Farias, P.; Hu, H.; Rubenstein, E.; Meneses-Gonzal ez, F.; Fishbein, E.; Palazuelos, E.; Aro, A.; Hernandez-Avila, M. (1998) Determinants of bone and blood lead levels among teenagers living in urban
areas with high lead exposure. Environ. Health Perspect. 106: 733-737.
Farrell, K. (1988) Baltimore soil-lead abatement demonstra tion project. In: Davies, B. E.; Wixson, B. G., eds. Lead in soil: issues and guidelines. Northwood, England: Science Review Limited; pp. 281-286. Environ.
Geochem. Health 9(suppl.). (Monograph series 4).
Fergusson, J. E.; Kinzett, N. G.; Fergusson, D. M.; Horwood, L. J. (1989) A longitudinal study of dentin lead levels and intelligence school performance and behavior the measurement of dentin lead. Sci. Total Environ.

80: 229-242. Flanagan, P. R.; Hamilton, D. L.; Haist, J.; Valberg, L. S. (1979) Interrelati onships between iron and lead absorption
in iron -deficient mice. Gastroenterology 77: 1074-1081.

# AX4-49 Flegal, A. R.; Smith, D. R. (1995) Measurements of environmental lead contamination and human exposure.
In: Ware, G. W., ed. Reviews of environmental contamination and toxicology, continuation of residue reviews, v. 143. New York, NY: Springer, pp. 1-45.
Fleming, D. E. B.; Boulay, D.; Richard, N. S.; Robin, J. -P.; Gordon, C. L.; Webber, C. E.; Chettle, D. R. (1997)
Accumulated body burden and endogenous release of lead in employees of a lead smelter. Environ. Health
Perspect. 105: 224-233. Fleming, D. E. B.; Chettle, D. R.; Wetmur, J. G.; Desnic k, R. J.; Robin, J.-P.; Boulay, D.; Richard, N. S.;
Gordon, C. L.; Webber, C. E. (1998) Effect of the δ -aminolevulinate dehydratase polymorphism on the

accumulation of lead in bone and blood in lead smelter workers. Environ. Res. 77: 49-61.
Forbes, G. B.; Bruining, G. B. (1976) Urinary creatin ine excretion and lean body mass. Am. J. Clin. Nutr.

29: 1359-1366.
Forbes, G. B.; Reina, J. C. (1972) E ffect of age on gastrointestinal absorp tion (Fe, Sr, Pb) in the rat. J. Nutr.

102: 647-652. Fosse, G.; Wesenberg, G. R.; Tvinnereim, H. M., Eide, R.; Kristoffersen, Ø.; Nag, O. H.; Wierzbicka, M.;
Banoczy, J.; De Oliveira, A. A.; Sris opak, C.; Zamudio, A. (1995) Lead in deciduous teeth from larger

cities of some countries. Int. J. Environ. Stud. 47: 203-210. Fowler, B. A. (1989) Biological roles of high affinity metal-binding proteins in mediating cell injury. Comments

Toxicol. 3: 27-46.
Fowler, B. A.; DuVal, G. (1991) Effects of lead on the kidney: roles of high-affinity lead-binding proteins. Environ. Health Perspect. 91: 77-80.
Frank, R. M.; Sargentini-Maier, M. L.; Turlot, J. C.; Leroy, M. J. (1990) Comparison of lead levels in human
permanent teeth from Strasbourg, Mexico City, and rural zones of Alsace. J. Dent. Res. 69: 90-93. Franklin, C. A.; Inskip, M. J.; Baccanal e, C. L.; Edwards, C. M.; Manton, W. I.; Edwards, E.; O'Flaherty, E. J.
(1997) Use of sequentially administer ed stable lead isotopes to investigate changes in blood lead during
pregnancy in a nonhuman primate ( Macaca fascicularis ). Fundam. Appl. Toxicol. 39: 109-119. Freeman, G. B.; Johnson, J. D.; Killinger, J. M.; Liao, S. C.; Feder, P. I.; Davi s, A. O.; Ruby, M. V.; Chaney, R. L.;
Lovre, S. C.; Bergstrom, P. D. (1992) Relative bioa vailability of lead from mining waste soil in rats.
Fundam. Appl. Toxicol. 19: 388-398.

Freeman, G. B.; Johnson, J. D.; Liao, S. C.; Feder, P. I.; Davis, A. O.; Ruby, M. V.; Sc hoof, R. A.; Chaney, R. L.;
Bergstrom, P. D. (1994) Absolute bioavailability of lead acetate and mining waste lead in rats. Toxicology

91: 151-163.

Freeman, G. B.; Dill, J. A.; Johnson, J. D.; Kurtz, P. J. ; Parham, F.; Matthews, H. B. (1996) Comparative absorption
of lead from contaminated soil and lead salts by weanling Fischer 344 rats. Fundam. Appl. Toxicol.

33: 109-119.

Garrido Latorre, F.; Hernández-Avila, M.; Orozco, J. T.; Medina, C. A. A.; Aro, A.; Palazuelos, E.; Hu, H. (2003)
Relationship of blood and bone lead to menopause and bone mineral density among middle-age women in Mexico City. Environ. Health Perspect. 111: 631-636.
Gerhardsson, L.; Brune, D.; Nordberg, G. F.; Wester, P. O. (1986) Distribution of cadmium, lead and zinc in lung,
liver and kidney in long-term exposed smelter workers. Sci. Total Environ. 50: 65-85. Gerhardsson, L.; Chettle, D. R.; Englyst, V.; Nordberg, G. F.; Nyhlin, H.; Scott, M. C.; Todd, A. C.; Vesterberg, O.
(1992) Kidney effects in long term exposed lead smelter workers. Br. J. Ind. Med. 49: 186-192.
Gerhardsson, L.; Attewell, R.; Chettle, D. R.; Englyst, V.; Lundström, N.-G.; Nordberg, G. F.; Nyhlin, H.;
Scott, M. C.; Todd, A. C. (1993) In vivo measuremen ts of lead in bone in long-term exposed lead smelter

workers. Arch. Environ. Health 48: 147-156.
Gerhardsson, L.; Hagmar, L.; Rylander, L.; Skerfving, S. (1995a) Mortality and cancer incidence among secondary lead smelter workers. Occup. Environ. Med. 52: 667-672.
Gerhardsson, L.; Englyst, V.; Lundström, N.G.; Nordberg, G.; Sandberg, S.; Steinvall, F. (1995b) Lead in tissues of

deceased lead smelter worker. J. Tr ace Elem. Med. Biol. 9: 136-143.

Gerr, F.; Letz, R.; Stokes, L.; Chettle, D.; McNeill, F.; Kaye, W. (2002) Association between bone lead
concentration and blood pressure among young adults. Am. J. Ind. Med. 42: 98-106.

Gil, F.; Facio, A.; Villanueva, E.; Pérez, M. L.; Tojo, R.; Gil, A. (1996) The association of tooth lead content with

dental health factors. Sci. Total Environ. 192: 183-191.

Glenn, B. S.; Stewart, W. F.; Links, J. M.; Todd, A. C.; Schwartz, B. S. (2003 ) The longitudinal association of lead with blood pressure. Epidemiology 14: 30-36.
Goering, P. L.; Fowler, B. A. (1987) Metal constitutio n of metallothionein influences inhibition of deltaaminolaevulinic acid dehydratase (porphobilinogen synthase) by lead. Biochem. J. 245: 339-345.

# AX4-50 Gomaa, A.; Hu, H.; Bellinger, D.; Schwartz, J.; Tsaih, S.-W.; Gonzalez-Cossio, T.; Schnaas, L.; Peterson, K.;
Aro, A.; Hernandez-Avila, M. (2002) Maternal bone lead as an independent risk factor for fetal neurotoxicity: a prospective study. Pediatrics 110: 110-118.

González-Cossío, T.; Peterson, K. E.; Sanín, L.-H.; Fishbein, E.; Palazuel os, E.; Aro, A.; He rnández-Avila, M.;
Hu, H. (1997) Decrease in birth weight in relation to maternal bone-lead burden. Pediatrics 100: 856-862. Goodrum, P. E.; Diamond, G. L.; Hassett, J. M.; Johnson, D. L. (1996) Monte Carlo modeling of childhood lead
exposure: development of a probabilistic methodology for use with the USEPA IEUBK model for lead in

children. Hum. Ecol. Ri sk Assess. 2: 681-708.

Gordon, C. L.; Chettle, D. R.; Webber, C. E. (1993) An improved instrument for the in vivo detection of lead in

bone. Br. J. Ind. Med. 50: 637-641.

Gordon, C. L.; Webber, C. E.; Chettle, D. R. (1994) The reproducibility of 109 

# Cd-based X-ray fluorescence

measurements of bone lead. Environ. Health Perspect. 102: 690-694.
Goyer, R. A. (1990) Lead toxicity: from overt to subclinical to subtle health effects. Environ. Health Perspect.

86: 177-181. Graziano, J. H. (1994) Validity of lead exposure markers in diagnosis and surveillance. Clin. Chem. 40: 1387-1390.
Graziano, J. H.; Popovac, D. ; Factor-Litvak, P.; Shrout, P.; Kline, J.; Murphy, M. J.; Zhao, Y.-H.; Mehmeti, A.; Ahmedi, X.; Rajovic, B.; Zvicer, Z.; Nenezic, D. U.; Lolacono, N. J.; Stein, Z. (1990) Determinants of
elevated blood lead during pregnancy in a population surrounding a lead smelter in Kosovo, Yugoslavia.

In: Conference on advances in lead research: im plications for environmental health; January 1989; Research Triangle Park, NC. Enviro n. Health Perspect. 89: 95-100.

Griffin, T. B.; Coulston, F.; Wills, H.; Russell, J. C.; Knelson, J. H. (1975 ) Clinical studies on men continuously
exposed to airborne particulate lead. In: Griffin, T. B.; Knelson, J. H., eds. Lead. Stuttgart, Federal Republic of Germany: Georg Thieme Publishers; pp. 22 1-240. (Coulston, F.; Korte, F., eds. Environmental
quality and safety: supplement v. 2).
Griffin, S.; Goodrum, P. E.; Diamond, G. L.; Meylan, W.; Brattin, W. J.; Hassett, J. M. (1999a) Application of a probabilistic risk assessment methodology to a lead sm elter site. Hum. Ecol. Risk Assess. 5: 845-868.

Griffin, S.; Marcus, A.; Schulz, T.; Wa lker, S. (1999b) Calculating the interindividual geometric standard deviation
for use in the integrated exposure uptake biokinetic model for lead in children. Environ. Health Perspect.

107: 481-487. Gross, S. B.; Pfitzer, E. A.; Yeager, D. W.; Kehoe, R. A. (1975) Lead in hum an tissues. Toxicol. Appl. Pharmacol.

32: 638-651. Gulson, B. L. (1996) Tooth analyses of sources and intensity of lead exposure in children. Environ. Health Perspect.

104: 306-312. Gulson, B.; Wilson, D. (1994) History of lead exposure in children revealed from isotopic analyses of teeth. Arch.

Environ. Health 49: 279-283.
Gulson, B. L.; Mahaffey, K. R.; Mizon, K. J.; Korsch, M. J.; Cameron, M. A.; Vimpani, G. (1995) Contribution of tissue lead to blood lead in adult female subjects based on stable lead isotope methods. J. Lab. Clin. Med.

125: 703-712. Gulson, B. L.; Jameson, C. W.; Mahaffey, K. R.; Mizon, K. J.; Korsch, M. J.; Vi mpani, G. (1997) Pregnancy

increases mobilization of lead from maternal skeleton. J. Lab. Clin. Med. 130: 51-62.
Gulson, B. L.; Mahaffey, K. R.; Jameson, C. W.; Mizon, K. J.; Korsch, M. J.; Camero n, M. A.; Eisman, J. A.
(1998a) Mobilization of lead from the skeleton during the postnatal period is larger than during pregnancy.

J. Lab. Clin. Med. 131: 324-329.
Gulson, B. L.; Jameson, C. W.; Mahaffey, K. R.; Mizon, K. J.; Patison, N.; Law, A. J.; Korsch, M. J.; Salter, M. A.
(1998b) Relationships of lead in breast milk to lead in blood, urine, and diet of the infant and mother. Environ. Health Perspect. 106: 667-674.
Gulson, B. L.; Gray, B.; Mahaffey, K. R.; Jameson, C. W.; Mizon, K. J.; Patison, N.; Korsch, M. J. (1999a)
Comparison of the rates of exchange of lead in the blood of newly born infants and their mothers with lead

from their current environment. J. Lab. Clin. Med. 133: 171-178.
Gulson, B. L.; Mahaffey, K. R.; Jameson, C. W.; Patison, N. ; Law, A. J.; Mizon, K. J.; Korsch, M. J.; Pederson, D.
(1999b) Impact of diet on lead in blood and urine in female adults and relevance to mobilization of lead from bone stores. Environ. Health Perspect. 107: 257-263.

Gulson, B. L.; Mizon, K. J.; Palmer, J. M.; Korsch, M. J. ; Donnelly, J. B. (2000) Urinary excretion of lead during pregnancy and postpartum. Sci. Total Environ. 262: 49-55.

Gulson, B. L.; Mizon, K. J.; Palmer, J. M.; Korsch, M. J. ; Taylor, A. J. (2001) Contribution of lead from calcium
supplements to blood lead. Environ. Health Perspect. 109: 283-288.

# AX4-51 Gulson, B.; Mizon, K.; Smith, H.; Eisman, J.; Palmer, J.; Ko rsch, M.; Donnelly, J.; Waite, K. (2002) Skeletal lead
release during bone resorption: effect of bisphosphon ate treatment in a pilot study. Environ. Health
Perspect. 110: 1017-1023.

Gulson, B. L.; Mizon, K. J.; Korsch, M. J.; Palmer, J. M. ; Donnelly, J. B. (2003) Mobilization of lead from human
bone tissue during pregnancy and lactation—a summary of long-term research. Sci. Total Environ.

303: 79-104.

Gulson, B. L.; Mizon, K. J.; Palmer, J. M.; Korsch, M. J.; Taylor, A. J.; Maha ffey, K. R. (2004) Blood lead changes
during pregnancy and postpartum with calcium supplementation. Environ. Health Perspect.

112: 1499-1507. Gwiazda, R.; Campbell, C.; Smith, D. (2005) A noninv asive isotopic approach to estimate the bone lead
contribution to blood in children: imp lications for assessing the efficacy of lead abatement. Environ. Health
Perspect. 113: 104-110.

Ha ć , E.; Czarnowski, W.; Gos, T.; Krechniak, J. (1997) Lead and fluoride content in human bone and hair in the

Gda ń sk region. Sci. Total Environ. 206: 249-254.

Hänninen, H.; Aitio, A.; Kovala, T.; Lu ukkonen, R.; Matikainen, E.; Mannelin, T.; Erkkilä, J.; Riihimäki, V. (1998)
Occupational exposure to lead and neuropsychological dysfunction. Occup. Environ. Med. 55: 202-209. Healy, M. A.; Harrison, P. G.; Aslam, M.; Davis, S. S.; Wilson, C. G. (1992) Lead sulphide and traditional
preparations: routes for in gestion, and solubility and reactions in gastric fluid. J. Clin. Hosp. Pharm.

7: 169-173. Heard, M. J.; Chamberlain, A. C. (1982) Effect of minerals and food on uptake of lead from the gastrointestinal tract

in humans. Hum. Toxicol. 1: 411-415.
Heard, M. J.; Chamberlain, A. C. (1983) Uptake of l ead by humans and effects of minerals and food. Sci. Total

Environ. 30: 245-253.

Heard, M. J.; Wells, A. C.; Newton, D.; Chamberlain, A. C. (1979) Human uptake and metabolism of tetra ethyl and
tetra methyl lead vapour labelled with 203 

# Pb. In: International conference: management and control of heavy metals in the environment; September; London, United Kingdom. Edinburgh, United Kingdom: CEP
Consultants, Ltd.; pp. 103-108.

Hernandez-Avila, M.; Gonzalez-Cossio, T. ; Palazuelos, E.; Romieu, I.; Aro, A.; Fishbein, E.; Peterson, K. E.; Hu, H. (1996) Dietary and environmental determinants of blood and bone lead levels in lactating
postpartum women living in Mexico City. Environ. Health Perspect. 104: 1076-1082.
Hernández-Avila, M.; Smith, D.; Meneses, F.; Sanin, L. H.; Hu, H. (1998) The influence of bone and blood lead on plasma lead levels in environmentally exposed adults. Environ. Health Perspect. 106: 473-477.
Hernandez-Avila, M.; Villalpano, C. G.; Palazuelos, E.; Villa pando, M. E. G. (2000) Determinants of blood lead levels across the menopausal transition. Arch. Environ. H ealth 53: 355-360.

Hernandez-Avila, M.; Peterson, K. E.; G onzalez-Cossio, T.; Sanin, L. H.; Aro, A.; Schnaas, L.; Hu, H. (2002) Effect
of maternal bone lead on length and head circumference of newborns and 1-month-old infants. Arch.

Environ. Health 57: 482-488.

Hernandez-Avila, M.; Gonzalez-Cossio, T.; Hernandez-Av ila, J. E.; Romieu, I.; Peterson, K. E.; Aro, A.;
Palazuelos, E.; Hu, H. (2003) Dietary calcium supplements to lower blood lead levels in lactating women: a randomized placebo-controlled tria l. Epidemiology 14: 206-212.

Hernandez-Guerrero, J. C.; Jimenez-Farfan, M. D.; Belmont, R.; Ledesma-Montes, C.; Baez, A. (2004) Lead levels
in primary teeth of children living in Mexico City. Int. J. Paediatr. Dent. 14: 175-181.

Hertz-Picciotto, I.; Schramm, M.; Watt- Morse, M.; Chantala, K.; Anderson, J. ; Osterloh, J. (2000) Patterns and
determinants of blood lead during pregnancy. Am. J. Epidemiol. 152: 829-837.
Hofmann, W.; Martonen, T. B.; Graham, R. C. (1989) Predicted deposition of nonhygroscopic aerosols in the human lung as a function of subject age. J. Aerosol Med. 2: 49-68.
Hogan, K.; Marcus, A.; Smith, R.; White, P. (1998) Inte grated exposure uptake biokinetic model for lead in
children: empirical comparisons w ith epidemiologic data. Environ. Health Perspect. 106(suppl. 6):

1557-1567. Hoppin, J. A.; Aro, A.; Hu, H.; Ryan, P. B. (2000) M easurement variability associated with KXRF bone lead
measurement in young adults. Environ. Health Perspect. 108: 239-242. Hu, H.; Milder, F. L.; Burger, D. E. (1990) X-ray fluoresc ence measurements of lead bu rden in subjects with lowlevel community lead exposure. Arch. Environ. Health 45: 335-341. Hu, H.; Watanabe, H.; Payton, M.; Korrick, S.; Rotnitzky , A. (1994) The relationship between bone lead and
hemoglobin. JAMA J. Am. Med. Assoc. 272: 1512-1517.

# AX4-52 Hu, H.; Aro, A.; Rotnitzky, A. (1995) Bone lead measured by X-ray fluorescence: epidemiologic methods. Environ.
Health Perspect. 103(suppl. 1): 105-110. Hu, H.; Aro, A.; Payton, M.; Korrick, S.; Sparrow, D.; Weiss, S. T.; Rotnitzky, A. (1996) The relationship of bone
and blood lead to hypertension. The Normative Aging Study. JAMA J. Am. Med. Assoc. 275: 1171-1176.
Hu, H.; Rabinowitz, M.; Smith, D. (1998) Bone lead as a biological marker in epidem iologic studies of chronic toxicity: conceptual paradigms. Environ. Health Perspect. 106: 1-8.
Hu, H.; Wu, M.-T.; Cheng, Y.; Sparrow, D.; Weiss, S.; Kelsey, K. (2001) The δ -aminolevulinic acid dehydratase
(ALAD) polymorphism and bone and blood lead levels in community-exposed men: the Normative Aging Study. Environ. Health Perspect. 109: 827-832.

Hursh, J. B.; Mercer, T. T. (1970) Measurement of 212 

# Pb loss rate from human lungs. J. Appl. Physiol. 28: 268-274.
Hursh, J. B.; Suomela, J. (1968) Absorption of 212 

# Pb from the gastrointestinal tract of man. Acta Radiol. 7: 108-120.

Hursh, J. B.; Schraub, A.; Sattler, E. L.; Hofmann, H. P. (1969) Fate of 212 

# Pb inhaled by human subjects. Health
Phys. 16: 257-267.

Hursh, J. B.; Clarkson, T. W.; Miles, E. F.; Goldsmith, L. A. (1989) Percutaneous absorption of mercury vapor by

man. Arch. Environ. Health 44: 120-127.
Inskip, M. J.; Franklin, C. A.; Baccanale, C. L.; Manton, W. I.; O' Flaherty, E. J.; Edwards, C. M. H.; Blenkinsop, J. B.; Edwards, E. B. (1996) Measurement of the flux of lead from bone to blood in a
nonhuman primate ( Macaca fascicularis ) by sequential administration of stable lead isotopes. Fundam.
Appl. Toxicol. 33: 235-245. International Commission on Radiological Protection. (1973) Alkaline earth metabolism in adult man. Oxford,
United Kingdom: Pergamon Press; ICRP publication 20. (Health Phys. 24: 125-221).
International Commission on Radiological Protection. (1975) Report of the task group on reference man: a report prepared by a task group of committee 2 of the International Commission on Radiological Protection.
Oxford, United Kingdom: Pergamon Press. (International Commission on Radiological Protection no. 23).
International Commission on Radiological Protection. (1989) Age-dependent doses to members of the public from intake of radionuclides: part 1. New York, NY: Pergamon Press. (ICRP publication 56; Annals of the
ICRP: v. 20, no. 2). International Commission on Radiological Protection. (1993) Age-specific biokinetics for the aIkalille earth elements. In: Age-dependent doses to members of the public from intake of radionuclides: part 2. Ingestion
dose coefficients. New York, NY: Elsevier Science, Inc.; pp. 95-120. (ICRP publication no. 67,
appendix A). International Commission on Radiological Protection (ICRP). (1994) Human respiratory tract model for radiological
protection: a report of a task group of the International Commission on Radiological Protection. Oxford, United Kingdom: Elsevier Science Ltd. (ICRP publication 66; Annals of the ICRP: v. 24, pp. 1-482).
International Commission on Radiological Protection. (1996) Basic anatomical & physiological data for use in
radiological protection: the skeleton. Oxford, United Kingdom: Elsevier Science Publishers; ICRP publication 70; Annals of the ICRP, v. 25, no. 2.
James, H. M.; Hilburn, M. E.; Blair, J. A. (1985) E ffects of meals and meal times on uptake of lead from the
gastrointestinal tract of humans. Hum. Toxicol. 4: 401-407.

James, A. C.; Stahlhofen, W.; Rudolf, G.; Köbrich, R.; Br iant, J. K.; Egan, M. J.; Nixon, W.; Birchall, A. (1994)
Deposition of inhaled particles. In: Human respiratory tr act model for radiological protection: a report of a
task group of the International Commission on Radiological Protection. Ann. ICRP 24(1-3): 231-299. (ICRP publication 66).
Juárez-Pérez, C. A.; Aguilar-Madrid, G.; Smith, D. R.; Lacasaña-Navarro, M. ; Téllez-Rojo, M. M.; Piacitteli, G.;
Hu, H.; Hernández-Avila, M. (2004) Predictors of pl asma lead among lithographic print shop workers in Mexico City. Am. J. Ind. Med. 46: 245-252.
Karakaya, A.; Ilko, M.; Ulusu, T.; Akal, N.; Isimer, A.; Ka rakaya, A. E. (1996) Lead levels in deciduous teeth of
children from urban and suburban regions of Ankara (Turkey). Bull. Environ. Contam. Toxicol. 56: 16-20.
Kehoe, R. A. (1987) Studies of lead administration and elimination in adult volunteers under natural and
experimentally induced conditions over extended periods of time. Food Chem. Toxicol. 25: 425-493.
Kehoe, R. A.; Thamann, F. (1931) The behavior of lead in the animal organism. II. Tetraethyl lead. Am. J. Hyg.

13: 478-498. Kessler, M.; Durand, P. Y.; Huu, T. C.; Royer-Morot, M. J.; Chanliau, J.; Netter, P.; Duc, M. (1999) Mobilization of lead from bone in end-stage renal failure patients with secondary hyperparathyroidism. Nephrol. Dial.
Transplant. 14: 2731-2733.

# AX4-53 Khoury, G. A.; Diamond, G. L. (2003) Risks to children from exposure to lead in air during remedial or removal
activities at Superfund sites: a case study of the RS R lead smelter superfund site. J. Exposure Anal. Environ. Epidemiol. 13: 51-65.
Kim, R.; Aro, A.; Rotnitzky, A.; Amar asiriwardena, C.; Hu, H. (1995) K x-ray fluorescence measurements of bone
lead concentration: the analysis of low-level data. Phys. Med. Biol. 40: 1475-1485. Kim, R.; Hu, H.; Rotnitzky, A.; Bellinger, D.; Needleman, H. (1996) Longitudinal relationship between dentin lead
levels in childhood and bone lead levels in young adulthood. Arch. Environ. Health 51: 375-382.
Kim, R.; Landrigan, C.; Mossmann, P.; Sparrow, D.; Hu, H. (1997) Age and secular trends in bone lead levels in middle-aged and elderly men: three-year longitudinal follow-up in the Normative Aging Study. Am. J.
Epidemiol. 146: 586-591.
Kondrashov, V. S.; Rothenberg, S. J. (2001a) How to calcu late lead concentration and concentration uncertainty in XRF in vivo bone lead analysis. Appl. Radiat. Isot. 55: 799-803.
Kondrashov, V. S.; Rothenberg, S. J. (2001b) One approach for doublet deconvolution to improve reliability in spectra analysis for in vivo lead measurement. Appl. Radiat. Isot. 54: 691-694.
Korrick, S. A.; Hunter, D. J.; Rotnitzky, A.; Hu, H.; Speizer, F. E. (1999) Lead and hypertension in a sample of
middle-aged women. Am. J. Public Health 89: 330-335.

Korrick, S. A.; Schwartz, J.; Tsaih, S.-W.; Hunter, D. J.; Ar o, A.;Rosner, B.; Speizer, F. E.; Hu, H. (2002) Correlates
of bone and blood lead levels among middle-aged and elderly women. Am. J. Epidemiol. 156: 335-343.
Kosnett, M. J.; Becker, C. E.; Osterloh, J. D.; Kelly, T. J.; Pasta, D. J. (1994) Factors influencing bone lead concentration in a suburban community assessed by noninvasive K x-ray fluorescence. JAMA J. Am. Med.

Assoc. 271: 197-203. Koster, J.; Erhardt, A.; Stoeppler, M.; Mohl, C.; Ritz, E. (1989) Mobilizable lead in patients with chronic renal

failure. Eur. J. Clin. Invest. 19: 228-233.
Kostial, K.; Kello, D.; Jugo, S.; Rabar, I.; Maljkovic, T. (1978) Influence of age on metal metabolism and toxicity.
Environ. Health Perspect. 25: 81-86.
Lacey, R. F.; Moore, M. R.; Richards, W. N. (1985) Lead in water, infant diet an d blood: the Glasgow Duplicate
Diet Study. Sci. Total Environ. 41: 235-257.
Lagerkvist, B. J.; Ekesrydh, S.; Englys t, V.; Nordberg, G. F.; Söderberg, H.-Å.; Wiklund, D.-E. (1996) Increased

blood lead and decreased calcium levels during pregnancy: a prospective study of Swedish women living

near a smelter. Am. J. Public Health 86: 1247-1252.
Lanphear, B. P.; Roghmann, K. J. (1997) Pathways of lead exposure in urban children. Environ. Res. 74: 67-73. Lanphear, B. P.; Burgoon, D. A.; Rust, S. W.; Eberly, S. ; Galke, W. (1998) Environmental exposures to lead and

urban children's blood lead levels. Environ. Res. 76: 120-130. Laug, E. P.; Kunze, F. M. (1948) The penetration of lead through the skin. J. Ind. Hyg. Toxicol. 30: 256-259.
Laxen, D. P. H.; Raab, G. M.; Fulton, M. (1987) Children's blood lead and exposure to lead in household dust and

water — a basis for an environmental standard for lead in dust. Sci. Total Environ. 66: 235-244.

Lee, B.-K; Ahn, K.-D.; Lee, S.-S.; Lee, G.-S.; Kim, Y. -B.; Schwartz, B. S. (1990) A comparison of different lead
biomarkers in their associations with lead-related symptoms. Int. Arch. Occup. Environ. Health

73: 298-304.

Lee, B.-K.; Lee, G.-S.; Stewart, W. F.; Ahn, K.-D.; Sim on, D.; Kelsey, K. T.; Todd, A. C.; Schwartz, B. S. (2001)
Associations of blood pressure and hypertension with lead dose measures and polymorphisms in the
vitamin D receptor and δ -aminolevulinic acid dehydratase genes. Environ. Health Perspect. 109: 383-389. Leggett, R. W. (1985) A model of the retention, tran slocation and excretion of systemic Pu. Health Phys.

49: 1115-1137. Leggett, R. W. (1992a) A retentio n-excretion model for americium in humans. Health Phys. 62: 288-310. Leggett, R. W. (1992b) A generic age-specific biokinetic model for calcium-like elements. Radiat. Prot. Dosim.

41: 183-198. Leggett, R. W. (1993) An age-specific kinetic model of lead metabolism in humans. Environ. Health Perspect.

101: 598-616.

Lilis, R.; Gavrilescu, N.; Nestorescu, B.; Dumitriu, C.; R oventa, A. (1968) Nephropathy in chronic lead poisoning.

Br. J. Ind. Med. 25: 196-202. Lin, J.-L.; Yu, C.-C.; Lin-Tan, D.-T.; Ho, H.-H. (2001) Lead chelation therapy and urate excretion in patients with
chronic renal diseases and gout. Kidney Int. 60: 266-271. Lin, C.; Kim, R.; Tsaih, S.-W.; Sparrow, D.; Hu, H. (2004) Determinants of bone and blood lead levels among
minorities living in the Boston area. Environ. Health Perspect. 112: 1147-1151.

# AX4-54 Lorenzana, R. M.; Troast, R.; Klotzbach, J. M.; Follansbee, M. H.; Diamond, G. L. (2005) Issues related to time
averaging of exposure in modeling risks associated with intermittent exposures to lead. Risk Anal.

25: 169-178. Lyngbye, T.; Hansen, O. N.; Grandjean, P. (1991) Lead concentration in deciduous teeth from Danish school

children. Dan. Med. Bull. 38: 89-93.

Maddaloni, M.; Lolacono, N.; Manton, W.; Blum, C.; Drexler, J.; Graziano, J. (1998) Bioavailability of soilborne
lead in adults, by stable isotope dilution. Environ. Health Perspect. 106: 1589-1594.
Maddaloni, M.; Ballew, M.; Diamond, G.; Follansbee, M.; Gefell, D.; Goodrum, P.; Johnson, M.; Koporec, K.; Khoury, G.; Luey, J.; Odin, M.; Troast, R.; Van Leeuwen, P.; Zaragoza, L. (2005) Assessing lead risks at

non-residential hazardous waste sites. Hum. Ecol. Risk Assess. 11: 967-1003.
Mahaffey, K. R.; Annest, J. L. (1986) Association of erythrocyte protoporphyrin with blood lead level and iron status in the second national health and nutrition examination survey, 1976-1980. Environ. Res.

41: 327-338. Mahaffey, K. R.; Gartside, P. S.; Glueck, C. J. (1986) Blood lead levels and dietary calcium intake in 1-11 year-old
children: the second national health and nutrition examination survey, 1976-1980. Pediatrics 78: 257-262.
Manton, W. I. (1985) Total contribution of airborne lead to blood lead. Br. J. Ind. Med. 42: 168-172. Manton, W. I.; Malloy, C. R. (1983) Distribution of lead in b ody fluids after ingestion of soft solder. Br. J. Ind. Med.

40: 51-57. Manton, W. I.; Cook, J. D. (1984) High accuracy (stabl e isotope dilution) measurements of lead in serum and cerebrospinal fluid. Br. J. Ind. Med. 41: 313-319.
Manton, W. I.; Angle, C. R.; Stanek, K. L.; Reese, Y. R.; Kuehnemann, T. J. (2000) Acquisition and retention of
lead by young children. Environ. Res. 82: 60-80. Manton, W. I.; Rothenberg, S. J.; Manalo, M. (2001) The lead content of blood serum. Environ. Res. 86: 263-273.
Manton, W. I.; Angle, C. R.; Stanek, K. L.; Kuntzelman, D.; Reese, Y. R.; Kuehnemann, T. J. (2003) Release of
lead from bone in pregnancy and lactation. Environ. Res. 92: 139-151. Marcus, A. H. (1985a) Multicompartment kinetic models fo r lead. II. Linear kinetics and variable absorption in
humans without excessive lead exposures. Environ. Res. 36: 459-472.
Marcus, A. H. (1985b) Multicompartment kinetic models for lead. I. Bone diffusion models for long-term retention.

Environ. Res. 36: 441-458.
Marcus, A. H. (1985c) Multicompartment kinetic model for lead. III. Lead in blood plasma and erythrocytes.

Environ. Res. 36: 473-489.
Marcus, A. H.; Elias, R. W. (1998) Some useful statistical methods for model validation. Environ. Health
Perspect.106(suppl. 6): 1541-1550. Marcus, A. H.; Schwartz, J. (1987) Dose-response curves for erythrocyte protoporphyrin vs blood lead: effects of

iron status. Environ. Res. 44: 221-227.
Markowitz, M. E.; Rosen, J. F. (1981) Zinc (Zn) and copper (Cu) metabolism in CaNa 2 

# EDTA-treated children with plumbism. Pediatr. Res. 15: 635.
Markowitz, M. E.; Weinberger, H. L. (1990) Immobilizati on-related lead toxicity in previously lead-poisoned

children. Pediatrics 86: 455-457. McMichael, A. J.; Baghurst, P. A.; Wigg, N. R.; Vimpani, G. V.; Robertson, E. F.; Roberts, R. J. (1988) Port Pirie
cohort study: environmental exposure to lead and child ren's abilities at the age of four years. N. Engl. J.

Med. 319: 468-475.

McNeill, F. E.; Stokes, L.; Chettle, D. R. ; Kaye, W. E. (1999) Factors affecting in vivo measurement precision and
accuracy of 109 

# Cd K x -ray fluorescence measurements. Phys. Med. Biol. 44: 2263-2273.

McNeill, F. E.; Stokes, L.; Brito, J. A.; Chettle, D. R.; Kaye, W. E. (2000) 109 

# Cd K x -ray fluorescence measurements of tibial lead content in young adults exposed to lead in early childhood . Occup. Environ. Med.

57: 465-471.
Mickle, M. H. (1998) Structure, use, and validation of th e IEUBK model. Environ. Health Perspect. 106(suppl. 6):

1531-1534.

Moline, J.; Carrillo, L. L.; Sanchez, L. T.; Godbold, J.; Todd, A. (2000) Lactation and lead body burden turnover: a
pilot study in Mexico. J. Occup. Environ. Med. 42: 1070-1075. Moore, M. R.; Meredith, P. A.; Campbell, B. C.; Goldberg, A.; Pocock, S. l. (1 977) Contribution of lead in drinking
water to blood-lead. Lancet (8039): 661-662.

Moore, M. R.; Meredith, P. A.; Watson, W. S.; Sumner, D. J.; Taylor, M. K.; Goldberg, A. (1980) The percutaneous
absorption of lead-203 in humans from cosmetic preparations containing lead acetat e, as assessed by
whole-body counting and other techniques. Food Cosmet. Toxicol. 18: 399-405.

# AX4-55 Morgan, W. D.; Ryde, S. J.; Jones, S. J.; Wyatt, R. M.; Hainsworth, I. R.; Cobbold, S. S.; Evans, C. J.;
Braithwaite, R. A. (1990) In vivo measurements of cadmium and lead in occupationally-exposed workers and an urban population. Biol. Trace Elem. Res. 26-27: 407-414.
Morrison, J. N.; Quarterman, J. (1987) The relationship between iron status and lead absorption in rats. Biol. Trace

Elem. Res. 14: 115-126. Morrow, P. E.; Beiter, H.; Amato, F.; Gibb, F. R. (1980) Pulmonary retention of lead: an experimental study in man.

Environ. Res. 21: 373-384.
Mortada, W. I.; Sobh, M. A.; El-Defrawy, M. M.; Farahat, S. E. (2001) Study of lead exposure from automobile exhaust as a risk for nephrotoxicity among traffic policemen. Am. J. Nephrol. 21: 274-279.
Mushak, P. (1989) Biological monitoring of lead exposure in children: overview of selected biokinetic and
toxicological issues. In: Smith, M. A.; Grant, L. D.; So rs, A. I., eds. Lead exposure and child development: an international assessment [workshop organized by the Commission of the European Communities and the
U.S. Environmental Protection Agency]; September 1986; Edinburgh, United Kingdom. Dordrecht, The Netherlands: Kluwer Academic Publishers BV; pp. 129-145.
Mushak, P. (1991) Gastro-intestinal absorption of lead in children and ad ults: overview of biological and
biophysico-chemical aspects. Chem. Speciation Bioavailability 3(3/4): 87-104. Mushak, P. (1993) New directions in the toxicokinetics of human lead exposure. Neurotoxicology 14: 29-42.
Mushak, P. (1998) Uses and limits of empirical data in measuring and modeling human lead exposure. Environ.
Health Perspect. Suppl. 106(6): 1467-1484. Mykkänen, H. M.; Wasserman, R. H. (1981) Gastrointestinal absorption of lead ( 203 

# Pb) in chicks: influence of lead,
calcium, and age. J. Nutr. 111: 1757-1765.
Mykkänen, H. M.; Wasserman, R. H. (1982) Effect of vitamin D on the intestinal absorption of 203 

# pb and 47 

# ca in

chicks. J. Nutr. 112: 520-527.
Nash, D.; Magder, L. S.; Sherwin, R.; Ru bin, R. J.; Silbergeld, E. K. (2004) Bone density-related predictors of blood
lead level among peri- and postmenopausal women in the United States: the Third National Health and Nutrition Examination Survey, 1988-1994. Am. J. Epidemiol. 160: 901-911.
National Institute for Occupational Safety and Health. (19 77a) Manual of analytical methods. 2nd ed. Cincinnati,
OH: U.S. Department of Health, Education, and Welf are, Public Health Serv ice, Centers for Disease Control, National Institute for Occupational Safety and Health. DHEW (NIOSH) publication no. 77/157-A.

Method No. P&CAM 102. V. 1.
National Institute for Occupational Safety and Health. (197 7b) Manual of analytical methods. 2nd ed. Cincinnati, OH: U.S. Department of Health, Education, and Welf are, Public Health Serv ice, Centers for Disease
Control, National Institute for Occupational Safety and Health. DHEW (NIOSH) publication no. 77/157-A.

Method No. P&CW 195. V. 1.
National Institute for Occupational Safety and Health. (19 77c) Manual of analytical methods. 2nd ed. Cincinnati,
OH: U.S. Department of Health, Education, and Welf are, Public Health Serv ice, Centers for Disease Control, National Institute for Occupational Safety an d Health, 200-1 to 200-8. Method No. P&CAM 200.

Vol. 1.
National Institute for Occupational Safety and Health. (197 7d) Manual of analytical methods. 2nd ed. Cincinnati, OH: U.S. Department of Health, Education, and Welf are, Public Health Serv ice, Centers for Disease
Control. National Institute for Occupational Safety an d Health. 214-1 to 214-6. Method No. P&CAM 214.

Vol. 1. National Institute for Occupational Safety and Health. (19 77e) Manual of analytical methods. 2nd ed. Cincinnati,
OH: U.S. Department of Health, Education and Welf are. Public Health Serv ice, Centers for Disease
Control, National Institute for Occupational Safety and Health. Method No. P&CAM 262. Vol. 1. National Institute for Occupational Safety and Health. (197 7f) Manual of analytical methods. 2nd ed. Cincinnati,
OH: U.S. Department of Health, Education, and Welf are, Public Health Serv ice, Centers for Disease
Control, National Institute for Occupational Safety and Health. Method No. P&CAM 208. Vol. 1. National Institute for Occupational Safety and Health. (198 4) Manual of analytical methods. 3rd ed. Cincinnati, OH:
U.S. Department of Health and Human Services, Ce nters for Disease Control, National Institute for
Occupational Safety and Health. Method No. 7300, 8003, and 8310. Vol. 1. National Institute for Occupational Safety and Health. (199 4) Manual of analytical methods. 4rd ed. Cincinnati, OH:
U.S. Department of Health and Human Services, Ce nters for Disease Control, National Institute for Occupational Safety and Health; DHHS (NIO SH) publication 94-113; method no. 7105.
National Institutes of Health (NIH) Consensus Developm ent Panel on Optimal Calcium Intake. (1994) Optimal
calcium uptake. JAMA J. Am. Med. Assoc. 272: 1942-1948.

# AX4-56 Nielsen, T.; Jensen, K. A.; Grandjean, P. (1978) Organic lead in normal human brains. Nature (London)

274: 602-603. Nielson, K. B.; Atkin, C. L.; Winge, D. R. (1985) Distinct metal-binding configurations in metallothionein. J. Biol.

Chem. 260: 5342-5350.

Nilsson, U.; Attewell, R.; Christoffersso n, J.-O.; Schutz, A.; Ahlgren, L.; Sker fving, S.; Mattsson, S. (1991) Kinetics of lead in bone and blood after end of occupational exposure. Pharmacol. Toxicol. (Copenhagen)

68: 477-484. Noda, H.; Sugiyama, S.; Yamaguchi, M.; Tatsumi, S.; Sano, Y.; Konishi, S.; Furutani, A.; Yoshimura, M. (1993) Studies on secular changes in the concentration of lead accumulated in organs and rib of Japanese. Jpn. J.
Leg. Med. 47: 147-152.
Nowak, B.; Chmielnicka, J. (2000) Relatio nship of lead and cadmium to essential elements in hair, teeth, and nails of environmentally exposed people. Ecotoxicol. Environ. Saf. 46: 265-274.
O'Flaherty, E. J. (1991a) Physiologically based models for bone-seeking elements. I. Rat skeletal and bone growth. Toxicol. Appl. Pharmacol. 111: 299-312.
O'Flaherty, E. J. (1991b) Physiologically based models fo r bone-seeking elements: II. kinetics of lead disposition in
rats. Toxicol. Appl. Pharmacol. 111: 313-331. O'Flaherty, E. J. (1991c) Physiologically based models for bone-seeking elements. III. Human skeletal and bone
growths. Toxicol. Appl. Pharmacol. 111: 332-341.
O'Flaherty, E. J. (1993) Physiologically based models for bone-seeking elements. IV. Kinetics of lead disposition in humans. Toxicol. Appl. Pharmacol. 118: 16-29.
O'Flaherty, E. J. (1995) Physiologically based models for bone-seeking elements: V. Lead absorption and
disposition in childhood. Toxicol. Appl. Pharmacol. 131: 297-308. O'Flaherty, E. J. (1998) A physiologically based kinetic model for lead in children and adults. Environ. Health
Perspect. 106(supp. 6): 1495-1503. O'Flaherty, E. J. (2000) Modeling normal aging bone loss, with consideration of bone loss in osteoporosis. Toxicol.

Sci. 55: 171-188.
O'Flaherty, E. J.; Hammond, P. B.; Lerner, S. I. (1982) Dependence of apparent blood lead half-life on the length of
previous lead exposure in humans. Fundam. Appl. Toxicol. 2: 49-54. O'Flaherty, E. J.; Inskip, M. J.; Frank lin, C. A.; Durbin, P. W.; Manton, W. I.; Baccanale, C. L. (1998) Evaluation
and modification of a physiologically based model of lead kinetics using data from a sequential isotope
study in cynomolgus monkeys. Toxico l. Appl. Pharmacol. 149: 1-16.

Oldereid, N. B.; Thomassen, Y.; Attramadal, A.; Olaisen, B.; Purvis, K. (1993) Concentrations of lead, cadmium
and zinc in the tissues of reproductive orga ns of men. J. Reprod. Fertil. 99: 421-425. Oliveira, S.; Aro, A.; Sparrow, D.; Hu, H. (2002) Season modifies the relationship between bone and blood lead
levels: the Normative Aging Study. Arch. Environ. Health 57: 466-472.
Ong, C. N.; Lee, W. R. (1980) Distribution of lead-203 in human peripheral blood in vitro. Br. J. Ind. Med.

37: 78-84. Orban, B. (1953) Oral histology and embryology. 3rd ed. St. Louis, MO: Mosby Year Book Publishers.
Oreskes, N. (1998) Evaluation (not validation) of quan titative models. Environ. Health Perspect. 106(suppl. 6):

1453-1460. Otto, D.; Robinson, G.; Baumann, S.; Schroeder, S.; Mushak, P.; Kleinbaum, D.; Boone, L. (1985) Five-year
follow-up study of children with low-to-moderate lead absorption: electroph ysiological evaluation.

Environ. Res. 38: 168-186.
Phalen, R. F.; Oldham, M. J. (2001) Methods for modeling pa rticle deposition as a function of age. Respir. Physiol.

128: 119-130. Pirkle, J. L.; Brody, D. J.; Gunter, E. W.; Kramer, R. A. ; Paschal, D. C.; Flegal, K. M.; Matte, T. D. (1994) The
decline in blood lead levels in the United States: the National Health and Nutrition Examination Surveys
(NHANES). JAMA J. Am. Med. Assoc. 272: 284-291. Pirkle, J. L.; Kaufmann, R. B.; Brody, D. J.; Hickman, T.; Gunter, E. W.; Paschal, D. C. (1998) Exposure of the U.S.
population to lead, 1991-1994. Environ. Health Perspect. 106: 745-750.
Pocock, S. J.; Shaper, A. G.; Walker, M.; Wale, C. J.; Clayton, B.; Delves, T.; Lacey, R. F.; Packham, R. F.; Powell, P. (1983) The effects of tap water lead, water hardness, alcohol, and cigarettes on blood lead
concentrations. J. Epidemiol. Community Health 37: 1-7. Popovic, M.; McNeill, F. E.; Chettle, D. R.; Webber, C. E.; Lee, C. V.; Kaye, W. E. (2005) Impact of occupational
exposure on lead levels in women. Environ. Health Perspect. 113: 478-484.

# AX4-57 Pounds, J. G.; Leggett, R. W. (1998) The ICRP age-sp ecific biokinetic model for lead: validations, empirical
comparisons, and explorations. Environ. Health Perspect. 106(suppl. 6): 1505-1511.

Pounds, J. G.; Marlar, R. J.; Allen, J. R. (1978) Metabolism of lead-210 in juvenile and adult rhesus monkeys
( Macaca mulatta ). Bull. Environ. Contam. Toxicol. 19: 684-691.
Powell, J. J.; Greenfield, S. M.; Thompson, R. P. H.; Carg nello, J. A.; Kendall, M. D.; Landsberg, J. P.; Watt, F.; Delves, H. T.; House, I. (1995) Assessment of toxic metal exposure following the Camelford water
pollution incident: evidence of acute mobilization of l ead into drinking water. Analyst (Cambridge, U. K.)

120: 793-798. Que Hee, S.S.; Boyle, J.R. (1988) Simultaneous multiele mental analysis of some environmental and biological
samples by inductively coupled plasma atomic emission spectrometry. Anal. Chem. 60: 1033-1042.
Que Hee, S. S.; MacDonald, T. J.; Bornschein, R. L. (1985) Blood lead by furnace-Zeeman atomic absorption spectrophotometry. Microchem. J. 32: 55-63.
Rabinowitz, M. B. (1991) Toxicokinetics of bone lead. Environ. Health Perspect. 91: 33-37. Rabinowitz, M. B. (1995) Relating tooth and blood lead levels in children. Bull. Environ. Contam. Toxicol.

55: 853-857. Rabinowitz, M. B.; Wetherill, G. W.; Kopple, J. D. (197 3) Lead metabolism in the normal human: stable isotope studies. Science (Washington, DC) 182: 725-727.
Rabinowitz, M. B.; Wetherill, G. W.; Kopple, J. D. (1976) Kinetic analysis of lead metabolism in healthy humans.

J. Clin. Invest. 58: 260-270. Rabinowitz, M. B.; Wetherill, G. W.; Kopple, J. D. (1977) Magnitude of lead intake from respiration by normal

man. J. Lab. Clin. Med. 90: 238-248.
Rabinowitz, M. B.; Kopple, J. D.; Wetherill, G. W. (1980) Effect of food intake and fasting on gastrointestinal lead absorption in humans. Am. J. Clin. Nutr. 33: 1784-1788.
Rabinowitz, M.; Needleman, H.; Burley, M.; Finch, H.; Rees, J. (1984) Lead in umbilical blood, indoor air, tap
water, and gasoline in Boston. Arch. Environ. Health 39: 299-301. Rabinowitz, M. B.; Leviton, A.; Bellinger, D. C. (1989) Blood lead—tooth lead relationship among Boston children.

Bull. Environ. Contam. Toxicol. 43: 485-492.
Rabinowitz, M. B.; Leviton, A.; Bellinge r, D. (1993) Relationships between serial blood lead levels and exfoliated

tooth dentin lead levels: models of tooth lead kinetics. Calcif. Tissue Int. 53: 338-341.
Roels, H.; Konings, J.; Green, S.; Br adley, D.; Chettle, D.; Lauwerys, R. (1995) Time-integrated blood lead
concentration is a valid surrogate for estimating the cumulative lead dose assessed by tibial lead

measurement. Environ. Res. 69: 75-82.
Rosen, J. F.; Pounds, J. G. (1 998) "Severe chronic lead insult that maintains body burdens of lead related to those in the skeleton": observations by Dr. Clair Patterson conclusively demonstrated. Environ. Res. 78: 140-151.
Rosen, J. F.; Markowitz, M. E.; Bijur, P. E.; Jenks, S. T.; Wielopolski, L.; Kalef-Ezra, J. A.; Slatkin, D. N. (1989)

L-line x -ray fluorescence of cortical bon e lead compared with the CaNa 2 

# EDTA test in lead-toxic children: public health implications. Proc. Natl. Acad. Sci. U. S. A. 86: 685-689.

Rosen, J. F.; Crocetti, A. F.; Balbi, K. ; Balbi, J.; Bailey, C.; Clemente, I.; Re dkey, N.; Grainger, S. (1993) Bone lead
content assessed by L-line x-ray fluorescence in lead-exposed and non-lead-exposed suburban populations

in the United States. Proc. Natl. Acad. Sci. U. S. A. 90: 2789-2792.
Rothenberg, S. J.; Karchmer, S.; Schnaas, L.; Perroni, E.; Zea, F.; Alba, J. F. (1994) Changes in serial blood lead
levels during pregnancy. Environ. Health Perspect. 102: 876-880. Rothenberg, S. J.; Khan, F.; Manalo, M.; Jian, J.; Cuella r, R.; Reyes, S.; Acosta, S.; Jauregui, M.; Diaz, M.;
Sanchez, M.; Todd, A. C.; Johnson, C. (2000) Maternal bone lead contribution to blood lead during and
after pregnancy. Environ. Res. 82: 81-90. Rothenberg, S. J.; Kondrashov, V.; Mana lo, M.; Manton, W. I.; Khan, F.; Todd, A. C.; Johnson, C. (2001) Seasonal
variation in bone lead contribution to blood lead during pregnancy. Environ. Res. 85: 191-194.
Rothenberg, S. J.; Kondrashov, V.; Manalo , M.; Jiang, J.; Cuellar, R.; Garcia, M.; Reynoso, B.; Reyes, S.; Diaz, M.; Todd, A. C. (2002) Increases in hypertension and blood pressure during pregnancy with increased bone
lead levels. Am. J. Epidemiol. 156: 1079-1087.
Ruby, M. V.; Schoof, R.; Brattin, W.; Go ldade, M.; Post, G.; Harnois, M.; Mosb y, D. E.; Casteel, S. W.; Berti, W.; Carpenter, M.; Edwards, D.; Cragin, D.; Chappell, W. (1999) Advances in evaluating the oral
bioavailability of inorganics in soil for use in human health risk assessment. Environ. Sci. Technol.

33: 3697-3705. Ryu, J. E.; Ziegler, E. E.; Nelson, S. E.; Fomon, S. J. (1983) Dietary intake of lead and blood lead concentration in
early infancy. Am. J. Dis. Child. 137: 886-891.

# AX4-58 Sakai, T.; Yanagihara, S.; Kunugi, Y.; Ushio, K. (1982) Relationships between distribution of lead in erythrocytes in

vivo and in vitro and inhibition of ALA-D. Br. J. Ind. Med. 39: 382-387. Salmon, P. L.; Bondarenko, O. A.; Henshaw, D. L. (1999) DOSE210, a semi-empirical model for prediction of
organ distribution and radiation doses from long term exposure to 210 

# Pb and 210 

# Po. Radiat. Prot. Dosim.

82: 175-192.

Saltzman, B. E.; Gross, S. B. ; Yeager, D. W.; Meiner s, B. G.; Gartside, P. S. (1990) Total body burdens and tissue
concentrations of lead, cadmium, copper, zinc, and ash in 55 human cadavers. Environ. Res. 52: 126-145.
Samuels, E. R.; Meranger, J. C.; Tracy, B. L.; Subramanian, K. S. (1989) Lead concentrations in human bones from the Canadian population. Sci. Total Environ. 89: 261-269.

Sanín, L. H.; González-Cossío, T.; Romieu, I.; Peterson , K. E.; Ruíz, S.; Palazuelos, E.; Hernández-Avila, M.;
Hu, H. (2001) Effect of maternal lead burden on infant weight and weight gain at one month of age among

breastfed infants. Pediatrics 107: 1016-1023.

Schafer, J. H.; Glass, T. A.; Bressler, J.; Todd, A. C. ; Schwartz, B. S. (2005) Blood lead in a predictor of homocysteine levels in a population-based study of older adults. Environ. Health Perspect. 113: 31-35.
Schnaas, L.; Rothenberg, S. J.; Perroni, E.; Martínez, S.; Hernández, C.; Hernández, R. M. (2000) Temporal pattern
in the effect of postnatal blood lead level on intellectual development of young children. Neurotoxicol.

Teratol. 22: 805-810.
Schroeder, H. A.; Tipton, I. H. (1968) The human body burden of lead. Arch. Environ. Health 17: 965-978.
Schuhmacher, M.; Hernández, M.; Domingo, J. L.; Fernánd ez-Ballart, J. D.; Llobet, J. M.; Corbella, J. (1996) A longitudinal study of lead mobilization during pregnancy: concentrations in maternal and umbilical cord

blood. Trace Elem. Electrol. 13: 177-181.
Schütz, A.; Skerfving, S.; Christoffersson, J. O.; Ahlgren, L.; Mattson, S. (1987a) Lead in vertebral bone biopsies

from active and retired lead workers. Arch. Environ. Health 42: 340-346.
Schütz, A.; Skerfving, S.; Ranstam, J.; Christoffersson, J.-O. (1987b) Kinetics of lead in blood after the end of
occupational exposure. Scand. J. Work Environ. Health 13: 221 231. Schütz, A.; Bergdahl, I. A.; Ekholm, A.; Skerfving, S. (1996) Measurement by ICP-MS of lead in plasma and whole
blood of lead workers and controls. Occup. Environ. Med. 53: 736-740.

Schwartz, B. S.; Stewar t, W. F.; Todd, A. C.; Links, J. M. (1999) Predictors of di mercaptosuccinic acid chelatable lead and tibial lead in former organolead manufacturing workers. Occup. Environ. Med. 56: 22-29.

Schwartz, B. S.; Lee, B.-K.; Lee, G.-S.; Stewart, W. F.; Simon, D.; Kelsey, K.; Todd, A. C. (2000a) Associations of
blood lead, dimercaptosuccinic acid-ch elatable lead, and tibia lead with polymorphisms in the vitamin D receptor and δ -aminolevulinic acid dehydratase genes. Environ. Health Perspect. 108: 949-954.

Schwartz, B. S.; Stewart, W. F.; Todd, A. C.; Simon, D.; Links, J. M. (2000b) Different associations of blood lead, meso 2,3-dimercaptosuccinic acid (DMS A)-chelatable lead, and tibial lead levels with blood pressure in
543 former organolead manufacturing workers. Arch. Environ. Health. 55: 85-92.

Schwartz, B. S.; Lee, B. K. ; Lee, G. S.; Stewart, W. F.; Lee, S. S.; Hwang, K. Y.; Ahn, K.-D.; Kim, Y.-B.;

Bolla, K. I.; Simon, D.; Parsons, P. J.; Todd, A. C. (2001) Associations of bl ood lead, dimercaptosuccinic

acid-chelatable lead, and tibia lead with neurobehavioral test scores in South Korean lead workers. Am.
J. Epidemiol. 153: 453-464. Shapiro, I. M.; Dobkin, B.; Tuncay, O. C.; Needleman, H. L. (1973) Lead levels in dentine and circumpulpal dentine
of deciduous teeth of normal and lead poisoned children. Clin. Chim. Acta 46: 119-123.
Sharma, K.; Reutergardh, L. B. (2000) Exposure of preschoolers to lead in the Makati area of Metro Manila, the Philippines. Environ. Res. A 83: 322-332.
Sherlock, J. C.; Quinn, M. J. (1986) Relationship between bl ood and lead concentrations and dietary lead intake in
infants: the Glasgow Duplicate Diet Study 1979-1980. Food Addit. Contam. 3: 167-176.

Sherlock, J.; Smart, G.; Forbes, G. I. ; Moore, M. R.; Patterson, W. J.; Ri chards, W. N.; Wilson, T. S. (1982)
Assessment of lead intakes and dose-response for a population in Ayr exposed to a plumbosolvent water
supply. Hum. Toxicol. 1: 115-122. Sherlock, J. C.; Ashby, D.; Delves, H. T. ; Forbes, G. I.; Moore, M. R.; Patterson , W. J.; Pocock, S. J.; Quinn, M. J.;
Richards, W. N.; Wilson, T. S. (1984) Reduction in expo sure to lead from drinking water and its effect on

blood lead concentrations. Hum. Toxicol. 3: 383-392. Silbergeld, E. K. (1991) Lead in bone: implications for toxicology during pregnancy and lactation. Environ. Health
Perspect. 91: 63-70. Silbergeld, E. K.; Schwartz, J.; Mahaffey, K. (1988) Lead and osteoporosis: mobilization of lead from bone in
postmenopausal women. Environ. Res. 47: 79-94.
Simons, T. J. B. (1993) Lead transport and binding by human erythrocytes in vitro. Pflugers Arch. 423: 307-313.

# AX4-59 Skerfving, S. (1988) Biological monitoring of exposure to inorganic lead. In: Clar kson, T. W.; Friberg, L.;
Nordberg, G. F.; Sager, R. P., eds. Biological monitoring of toxic metals. New York, NY: Plenum Press;
pp. 169-197. Skerfving, S.; Ahlgren, L.; Christoffersson, J.-O.; Haeg er-Aronsen, B.; Mattsson, S.; Schütz, A. (1983) Metabolism
of inorganic lead in occupationally exposed humans. Arh. Hig. Rada Toksikol. 34: 341-350. Skerfving, S.; Ahlgren, L.; Christoffersson, J -O.; Haeger-Aronson, B.; Mattsson, S.; Schütz, A; Lindberg, G. (1985)
Metabolism of inorganic lead in man. Nutr. Res. Suppl. 1: 601.
Skerfving, S.; Nilsson, U.; Schütz, A.; Gerhardsson, L. (1993) Biological monitoring of inorganic lead. Scand. J. Work Environ. Health 19(suppl. 1): 59-64.
Smith, D. R.; Osterloh, J. D.; Flegal, A. R. (1996) Use of endogenous, stable lead isot opes to determine release of
lead from the skeleton. Environ. Health Perspect. 104: 60-66. Smith, D. R.; Kahng, M. W.; Quintanilla-Vega, B.; Fowler, B. A. (1998a) High-affinity renal lead-binding proteins
ini environmentally-exposed humans. Chem. Biol. Interact. 115: 39-52.

Smith, D. R.; Ilustre, R. P.; Osterloh, J. D. (1998b) Methodological considera tions for the accurate determination of
lead in human plasma and serum. Am. J. Ind. Med. 33: 430-438.
Smith, D.; Hernandez-Avila, M.; Téllez-Rojo, M.M.; Mercado, A.; Hu, H. (2002) The relationship between lead in plasma and whole blood in women. Environ. Health Perspect. 110: 263-268.

Somervaille, L. J.; Chettle, D. R.; Scott, M. C.; Aufder heide, A. C.; Wallgren, J. E.; Wittmers, L. E., Jr.;
Rapp, G. R., Jr. (1986) Comparison of two in vitro methods of bone lead analysis and the implications for

in vivo measurements. Phys. Med. Biol. 31: 1267-1274.

Somervaille, L. J.; Chettle, D. R.; Scott, M. C.; Tennant, D. R.; McKiernan, M. J.; Sk ilbeck, A.; Trethowan, W. N.
(1988) In vivo tibia lead measurements as an index of cumulative exposure in occupationally exposed subjects. Br. J. Ind. Med. 45: 174-181.

Somervaille, L. J.; Nilsson, U.; Chettle, D. R.; Tell, I.; Sco tt, M. C.; Schütz, A.; Mattsson, S.; Skerfving, S. (1989)

In vivo measurements of bone lead—a comparison of tw o x-ray fluorescence techniques used at three different bone sites. Phys. Med. Biol. 34: 1833-1845.
Stauber, J. L.; Florence, T. M.; Gulson, B. L.; Dale, L. S. (1994) Percutaneous absorption of inorganic lead
compounds. Sci. Total Environ. 145: 55-70. Stern, A. H. (1994) Derivation of a target level of lead in soil at residential sites corresponding to a de minimis

contribution to blood lead concentration. Risk Anal. 14: 1049-1056.
Stern, A. H. (1996) Derivation of a target concentration of Pb in soil based on elevation of adult blood pressure.

Risk Anal. 16: 201-210.

Stokes, L.; Letz, R.; Gerr, F.; Kolczak, M.; McNeill, F. E.; Chettle, D. R.; Kaye, W. E. (1998) Neurotoxicity in young adults 20 years after childhood exposure to lead: the Bunker Hill experience. Occup. Environ. Med.

55: 507-516. Succop, P.; Bornschein, R.; Brown, K.; Tseng, C.-Y. (1998) An empirical comparison of lead exposure pathway models. Environ. Health Perspect. Suppl. 106(6): 1577-1583.
Sun, C. C.; Wong, T. T.; Hwang, Y. H.; Chao, K. Y.; Jee, S. H.; Wang, J. D. (2002) Percutaneous absorption of
inorganic lead compounds. AIHA J. 63: 641-646. Symanski, E.; Hertz-Picciotto, I. (1995) Blood lead levels in relation to menopause, smoking, and pregnancy
history. Am. J. Epidemiol. 141: 1047-1058.
Téllez-Rojo, M. M.; Hernández-Avila, M. ; González-Cossío, T.; Romieu, I.; Aro, A.; Palazuelos, E.; Schwartz, J.; Hu, H. (2002) Impact of breastfeeding on the mobilization of lead from bone. Am. J. Epidemiol.

155: 420-428. Téllez-Rojo, M. M.; Hernández-Avila, M.; Lamadrid-Figueroa, H.; Smith, D.; Hernández- Cadena, L.; Mercado, A.; Aro, A.; Schwartz, J.; Hu, H. (2004) Impact of bone lead and bone resorption on plasma and whole blood
lead levels during pregnancy. Am. J. Epidemiol. 160: 668-678.
TerraGraphics Environmental Engineering, Inc. (2000) 1999 five year review report: Bunker Hill Superfund site. [Final]. Available: http://yosemite.epa.gov/r10/clea nup.nsf/webpage/Idaho+Cleanup+Sites [1 May, 2006].
TerraGraphics Environmental Engineering, Inc.; URS Greiner, Inc. (2001) Human health risk assessment for the
Coeur d'Alene Basin extending from Harrison to Mullan on the Coeur d'Alene River and Tributaries remedial investigation/feasibility study [final]. Prepar ed for: Idaho Department of Health and Welfare,
Division of Health; Idaho Department of Environmental Quality and U.S. Environmental Protection Agency, Region 10; June.
Todd, A. C. (2000) Coherent scattering and matrix correction in bone-lead measurements. Phys. Med. Biol.

45: 1953-1963.

# AX4-60 Todd, A. C.; Chettle, D. R. (2003) Calculatin g the uncertainty in lead concentration for in vivo bone lead x-ray
fluorescence. Phys Med Biol. 48: 2033-2039.

Todd, A. C.; Carroll, S.; Godbold, J. H.; Moshier, E. L. ; Khan, F. A. (2000) Variability in XRF-measured tibia lead
levels. Phys. Med. Biol. 45: 3737-3748.

Todd, A. C.; Buchanan, R.; Carroll, S.; Moshier, E. L.; P opovac, D.; Slavkovich, V.; Graziano, J. H. (2001) Tibia lead levels and methodological uncertainty in 12-year-old children. Environ. Res. 86: 60-65.
Todd, A. C.; Carroll, S.; Geraghty, C.; Khan, F. A.; Moshier, E. L.; Tang, S.; Parsons, P. J. (2002a) L-shell x-ray

fluorescence measurements of lead in bone: accur acy and precision. Phys. Med. Biol. 47: 1399-1419.

Todd, A. C.; Parsons, P. J.; Carroll, S.; Geraghty, C.; Khan, F. A.; Tang, S.; Moshier, E. L. (2 002b) Measurements
of lead in human tibiae. A comp arison between K-shell x-ray fluore scence and electrothermal atomic
absorption spectrometry. Phys. Med. Biol. 47: 673-687. Treble, R. G.; Thompson, T. S. (1997) Preliminary results of a survey of lead levels in human liver tissue. Bull.

Environ. Contam. Toxicol. 59: 688-695.

Tsaih, S.-W.; Schwartz, J.; Lee, M. -L. T.; Amarasiriwardena, C.; Aro, A. ; Sparrow, D.; Hu, H. (1999) The
independent contribution of bone and erythrocyte lead to urinary lead among middle-aged and elderly men:
the normative aging study. Environ. Health Perspect. 107: 391-396.

Tsaih, S.-W.; Korrick, S.; Schwartz, J. ; Amarasiriwardena, C.; Ar o, A.; Sparrow, D; Hu, H. (2004) Lead, diabetes,
hypertension, and renal function: the Normative Aging Study. Environ. Health Perspect. 112: 1178-1182.
Tsuji, L. J.; Karagatzides, J. D.; Ka tapatuk, B.; Young, J.; Kozlovic, D. R.; Hannin, R. M.; Nieboer, E. (2001)

Elevated dentine-lead levels in deciduous teeth collected from remote first nation communities located in
the western James Bay region of northern Ontario, Canada. J. Environ. Monit. 3: 702-705.
Turlakiewicz, Z.; Chmielnicka, J. (1985) Diethyllead as a specific indi cator of occupational exposure to tetraethyllead. Br. J. Ind. Med. 42: 682-685.
Tuthill, R. W. (1996) Hair lead leve ls related to children's classroom atte ntion-deficit behavior. Arch. Environ.

Health 51: 214-220. Tvinnereim, H. M.; Eide, R.; Riise, T.; Wesenberg, G. R.; Fosse, G.; Steinnes, E. (1997) Lead in primary teeth from
Norway: changes in lead levels from the 1970s to the 1990s. Sci. Total Environ. 207: 165-177.
U.S. Environmental Protection Agency. (1986) Air quality criteria for lead. Research Triangle Park, NC: Office of

Health and Environmental Assessment, Environmental Criteria and Assessment Office; EPA report no.
EPA-600/8-83/028aF-dF. 4v. Available from: NTIS, Springfield, VA; PB87-142378.
U.S. Environmental Protection Agency. (1994a) Guidance manual for the integrated exposure uptake biokinetic model for lead in children. Washington, DC: Office of Emergency and Remedial Response; report no.
EPA/540/R-93/081. Available from: NTIS, Springfield, VA; PB93-963510. U.S. Environmental Protection Agency. (1994b) Technical support document: parameters and equations used in
integrated exposure uptake biokinetic model for lead in children (v 0.99d). Washington, DC: Office of
Solid Waste and Emergency Response; report no. EPA/540/R-94/040. Available from: NTIS, Springfield,

VA; PB94-963505. U.S. Environmental Protection Agency. (1994c) Revised interim soil lead guidance for CERCLA sites and RCRA

corrective action facilities [memorandum from EPA's Assistant Administrator for Solid Waste and Emergency Response to regional administrators I-X]. Washington, DC: U.S. Environmental Protection
Agency, Office of Solid Waste and Emergency Response; OSWER directive no. 9355.4-12; report no.
EPA/540/F-94/043; July 14. Available from: NTIS, Springfield, VA; PB94-963282. U.S. Environmental Protection Agency. (1996a) Recommendations of the Technical Review Workgroup for Lead
for an interim approach to assessing risks associated with adult exposu res to lead in soil. Draft report.
Washington, DC: Technical Review Workgroup for Lead. Available: www.epa.gov/superfund/programs/lead/products/adultpb.pdf [1999, November 23].
U.S. Environmental Protection Agency. (1996b) Urban soil lead abatement demonstration project. Volume I: EPA
integrated report. Research Triangle Park, NC: Office of Research and Development, National Center for Environmental Assessment; report no. EPA/600/P-93/001aF. Available from: NTIS, Springfield, VA;

PB96-168356. U.S. Environmental Protection Agency. (1998a) Health risks from low level environmental exposures to radionuclides. Federal guidance report no. 13—par t 1: interim version. Washington, DC: U.S.
Environmental Protection Agency, Office of Radiation and Indoor Air; report no. EPA 402-R-97-014.

# AX4-61 U.S. Environmental Protection Agency. (1998b) Clarifica tion to the revised interim soil lead guidance for CERCLA
sites and RCRA corrective action facilities Washingt on, DC: U.S. Environmental Protection Agency,Office of Solid Waste and Emergency Response; OSWER directive no. 9200.4-27P; report no. EPA/540/F98/030; [28 August 2006]. Available online at: http://www.epa.gov/superfund/lead/products/oswer98.pdf.
U.S. Environmental Protection Agency. (2 002) Blood lead concentrations of U. S. adult females: summary statistics from phases 1 and 2 of the national health and nu trition avaluation survey ( NHANES III). Washington,
DC: U.S. Environmental Protection Agency, Office of Solid Waste and Emergency Response; OSWER
directive no. 9285.7-52; report no. EPA/540/F-98/030; [28 August 2006]. Available online at: http://www.epa.gov/superfund/l ead/products/nhanes.pdf.
U.S. Environmental Protection Agency (2003a) Assessing intermittent or variable exposures at lead sites.
Washington, DC: Office of Solid Waste and Emergency Response; report no. EPA-540-R-03-008; OSWER# 9285.7-76. Available: http://www.epa.gov/superfund/lead/products/twa-final-nov2003.pdf

[10 March, 2006]. U.S. Environmental Protection Agency. (2003b) Evalua tion of the ICRP Lead Biokinetics Model: empirical
comparisons with observations of plasma-blood lead concentration relationships in humans. Washington,
DC: Office of Emergency and Remedial Response; FEDSIM order no. DABT; Syracuse Research Corporation; contract no. GS-10F-0137K.
U.S. Environmental Protection Agency. (2003c) Recommendations of the Technical Review Workgroup for lead for
an approach to assessing risks asso ciated with adult exposures to lead in soil. Washington, DC: Technical Review Workgroup for Lead; EPA-540-R-03-001. Available:
http://www.epa.gov/superfund/lead/produ cts/adultpb.pdf [11 May, 2006].
U.S. Environmental Protection Agency. (2005) All ages l ead model [draft version 1.05]. Research Triangle Park,

NC: National Center for Environmental Assessment.
Ulmer, D. D.; Vallee, B. L. (1969) Effects of lead on biochemical syst ems. In: Hemphill, D. D., ed. Trace
Substances in Environmental Health, proceedings of the University of Missouri's 2nd annual conference; July, 1968; Columbia, MO. Columbia, MO: University of Missouri; pp. 7-27.
Van De Vyver, F. L.; D'Haese, P. C.; Visser, W. J.; Elsevi ers, M. M.; Knippenberg, L. J.; Lamberts, L. V.; Wedeen,
R. P.; De Broe, M. E. (1988) Bone lead in dialysis patients. Kidney Int. 33: 601-607. Vural, N.; Duydu, Y. (1995) Biological monitoring of lead in workers exposed to tetraethyllead. Sci. Total Environ.

171: 183-187.
Waalkes, M. P.; Klaassen, C. D. (1985) Concentration of me tallothionein in major organs of rats after administration of various metals. Fundam. Appl. Toxicol. 5: 473-477.
Waalkes, M. P.; Harvey, M. J.; Klaasse n, C. D. (1984) Relative in vitro affinity of hepatic metallothionein for

metals. Toxicol. Lett. 20: 33-39.

Wasserman, G. A.; Graziano, J. H.; Factor-Litvak, P.; Po povac, D.; Morina, N.; Musabegovic, A.; Vrenezi, N.;
Capuni-Paracka, S.; Lekic, V.; Preten i-Redjepi, E.; Hadzialjevic, S.; Sla vkovich, V.; Kline, J.; Shrout, P.; Stein, Z. (1994) Consequences of lead exposure and iron supplementation on childhood development at age
4 years. Neurotoxicol. Teratol. 16: 233-240.

Watson, W. S.; Morrison, J.; Be thel, M. I. F.; Baldwin, N. M.; Lyon, D. T. B.; Dobson, H.; Moore, M. R.; Hume, R. (1986) Food iron and lead absorption in humans. Am. J. Clin. Nutr. 44: 248-256.

Webber, C. E.; Chettle, D. R.; Bowins, R. J.; Beaumont, L. F.; Gordon, C. L.; Song, X.; Bl ake, J. M.; McNutt, R. H.
(1995) Hormone replacement therapy may reduce th e return of endogenous lead from bone to the circulation. Environ. Health Perspect. 103: 1150-1153.
Wedeen, R. P. (1992) Removing lead from bone: clinical implications of bone lead stores. Neurotoxicology

13: 843-852.

Wedeen, R. P.; Maesaka, J. K.; Weiner , B.; Lipat, G. A.; Lyons , M. M.; Vitale, L. F.; Joselow, M. M. (1975)
Occupational lead nephropathy. Am. J. Med. 59: 630-641.
Weis, C. P.; Lavelle, J. M. (1991) Char acteristics to consider when choosing an animal model for the study of lead bioavailability. Chem. Speciation Bioavailability 3: 113-119.
Weitzman, M.; Aschengrau, A.; Bellinger, D.; Jones, R.; Ha mlin, J. S. (1993) Lead-con taminated soil abatement and

urban children's blood lead levels. JAMA J. Am. Med. Assoc. 269: 1647-1654. Wells, A. C.; Venn, J. B.; Heard, M. J. (1977) Deposition in the lung and uptake to blood of motor exhaust labelled

with 203 

# Pb. In: Walton, W. H.; McGovern, B., eds. Inhale d particles IV: proceedings of an international symposium, part 1; September 1975; Edinburgh, United Kingdom. Oxford, United Kingdom: Pergamon
Press, Ltd.; pp. 175-189.

# October 2006

EPA/600/R-05/144bF



# Air Quality Criteria for Lead

Volume II of II

# EPA/600/R-05/144bF

October 2006



# Air Quality Criteria for Lead

Volume II

National Center for Environmental Assessment-RTP Division
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, NC

# PREFACE

National Ambient Air Quality Standards (NAAQS ) are promulgated by the United States

Environm ental Protection Agency (EPA) to meet requirements set forth in Sections 108 and 109

of the U.S. Clean Air Act. Those two Clean Air Act sections require the EPA Administrator

(1) to list widespread air pollutants that reasonabl y m ay be expected to endanger public health or

welfare; (2) to issue air qualit y criteria for them that assess the latest available scientific

information on nature and effects of ambient e xposure to them; (3) to set “primary” NAAQS to

protect human health with ade quate margin of safety and to set “secondary” NAAQS to protect

against welfare effects (e.g., effects on vegeta tion, ecosystems, visibility, climate, manmade

materials, etc); and (5) to peri odically review and revise, as appropriate, the criteria and NAAQS

for a given listed pollutant or class of pollutants.

Lead was first listed in the mid-1970’s as a “criteria air pollutant” requiring NAAQS

regulation. The scientific inform ation pertinent to Pb NAAQS de velopment available at the time

was assessed in the EPA document Air Quality Criteria for Lead ; published in 1977. Based on

the scientific assessments contained in that 1977 lead air quality criteria document (1977 Lead

AQCD), EPA established a 1.5 μg/m 3 

# (maximum quarterly calendar average) Pb NAAQS in

1978.

To meet Clean Air Act requirements noted above for periodic review of criteria and

NAAQS, ne w scientific information published si nce the 1977 Lead AQCD was later assessed in

a revised Lead AQCD and Addendum published in 1986 and in a Supplement to the 1986

AQCD/Addendum published by EPA in 1990. A 1990 L ead Staff Paper, prepared by EPA’s

Office of Air Quality Planning and Standards (OPQPS), drew upon key findings and conclusions

from the 1986 Lead AQCD/Addendum and 1990 Supplement (as well as other OAQPSsponsored lead exposure/risk analyses) in posing options for the EPA Administrator to consider

with regard to possible revision of the Pb NAAQS . However, EPA chose not to revise the Pb

NAAQS at that time. Rather , as part of implementing a broad 1991 U.S. EPA Strategy for

Reducing Lead Exposure, the Agency focused primarily on regulatory and remedial clean-up

efforts to reduce Pb exposure from a variety of non-air sources that posed more extensive public

health risks, as well as other actions to reduce air emissions.

The purpose of this revised Lead AQCD is to critically assess the latest scientific

inform ation that has become available sin ce the literature asse ssed in the 1986 Lead

II-iii

# AQCD/Addendum and 1990 Supplement, with the main focus being on pertinent new

information useful in evaluating health and enviro nmental effects of ambien t air lead exposures.

This includes discussion in this document of information rega rding: the nature, sources,

distribution, measurement, and c oncentrations of lead in the environment; multimedia lead

exposure (via air, food, water, et c.) and biokinetic modeling of c ontributions of such exposures

to concentrations of lead in brain, kidney, a nd other tissues (e.g., blood and bone concentrations,

as key indices of lead exposure).; characterization of l ead health effects and associated exposureresponse relationships; and delineation of environmen tal (ecological) effects of lead. This final

version of the revised Lead AQCD mainly assesses pertinent literature published or accepted for

publication through December 2005.

The First External Review Draft (dated Decem ber 2005) of the revised Lead AQCD

underwent public comment and was reviewed by the Clean Air Scientific Advisory Committee

(CASAC) at a public meeting held in Durham , NC on February 28-March 1, 2006. The public

comments and CASAC recommendations receiv ed were taken into account in making

appropriate revisions and incorporating them in to a Second External Review Draft (dated May,

2006) which was released for further public co mment and CASAC review at a public meeting

held June 28-29, 2006. In addition, still further revised drafts of the Integrative Synthesis

chapter and the Executive Summary were then issued and discussed during an August 15, 2006

CASAC teleconference call. Public commen ts and CASAC advice received on these latter

materials, as well as Second External Review Draf t materials, were taken into account in making

and incorporating further revisions into this fi nal version of this Lead AQCD, which is being

issued to meet an October 1, 2006 court-ordered d eadline. Evaluations c ontained in the present

document provide inputs to an associated Lead Staff Paper prepared by EPA’s Office of Air

Quality Planning and Standards (OAQPS), which poses options for consideration by the EPA

Administrator with regard to proposal and, ul timately, promulgation of decisions on potential

retention or revision, as appropriate, of the current Pb NAAQS.

Preparation of this document has been coordi nated by staff of EPA’s Nat ional Center for

Environmental Assessment in Research Triangl e Park (NCEA-RTP). NCEA-RTP scientific

staff, together with experts from academia, contri buted to writing of docum ent chapters. Earlier

drafts of document materials were reviewed by scientists from other EPA units and by non-EPA

experts in several public peer consultation workshops held by EPA in July/August 2005.

II-iv

# NCEA acknowledges the valuab le contributions provided by authors, contributors, and

reviewers and the diligence of its staff and contractors in the prep aration of this document. The

constructive comments provided by public comment ers and CASAC that served as valuable

inputs contributing to improved scientific and editorial quality of the document are also

acknowledged by NCEA.

DISCLAIMER

Mention of trade names or commercial produc ts in this docum ent does not constitute

endorsement or recommendation for use.

.

II-v

# Air Quality Criteria for Lead (Second External Review Draft)

VOLUME I

EXECUTIVE SUMMARY

......................................................................................................... E-1

1. INTRODUCTION

........................................................................................................... 1-1

2. CHEMISTRY, SOURCES, AN D TRANSPORT OF LEAD

.......................................... 2-1

3. ROUTES OF HUMAN EXPOSURE TO LEAD AND OBSERVED

ENVIRONMENTAL CONCENTRATIONS

.................................................................. 3-1

4. TOXICOKINETICS, BIOLOGICAL MARKERS, AND MODELS OF LEAD

BURDEN I N HUMANS

.................................................................................................. 4-1

5. TOXICOLOGICAL EFFECTS OF LEAD IN LABORATORY ANIMALS

AND IN VITRO TE ST SYSTEMS

................................................................................. 5-1

6. EPIDEMIOLOGIC STUDIES OF HUMAN HEALTH EFFECTS

ASSOCIATED W ITH LEAD EXPOSURE

.................................................................... 6-1

7. ENVIRONMENTAL EFFECTS OF LEAD

................................................................... 7-1

8. INTEGRATIVE SYNTHESIS OF LEAD EXPOSURE/HEALTH

EFFECTS INFORM ATION

............................................................................................ 8-1



# VOLUME II

CHAPTER 4 ANNEX (TOXICOKINETICS , BIOLOGICAL MARKERS, AND
MODELS OF LEAD BURDEN IN HUMANS) ............................................. AX4-1

CHAPTER 5 ANNEX (TOXICOLOGICAL EFFECTS OF LEAD IN

LABORATORY ANIM ALS AND IN VITRO TEST SYSTEMS) ................ AX5-1

CHAPTER 6 ANNEX (EPIDEMIOLOGIC ST UDIES OF HUMAN HEALTH

EFFECTS ASSOCIATED WITH LEAD EXPOSURE) ................................. AX6-1

CHAPTER 7 ANNEX (ENVIRONMENTA L E FFECTS OF LEAD).................................. AX7-1

II-vi

# Table of Contents

Page

PREFACE ........................................................................................................................

.......... II- iii

D I SCLAIMER

..................................................................................................................... ....... II-v

List of Tables

................................................................................................................. ............. II-x

Authors, Contributors, and Reviewers..................................................................................... II-xxi

U.S. Environmental Protection Agency Project Team for Development of Air
Quality Criteria for Lead................................................................................................. II-xx vii

U.S. Environmental Protection Agency Science Advisory Board (SAB) Staff
Office Clean Air Scientific Advisory Committee (CASAC)........................................... II-xxix

Abbreviatio ns and Acronyms ................................................................................................ II-xx xi

AX5. CHAPTER 5 ANNEX (TOXICOLOGICAL EFFECTS OF LEAD IN

LABORATORY ANIMALS AND IN VITRO TEST SYSTEMS ................. AX5-1

ANNEX TABLES AX5-2 ....................................................................................... AX5-1

ANNEX TABLES AX5-3 ..................................................................................... AX5-15

ANNEX TABLES AX5-4 ..................................................................................... AX5-37

ANNEX TABLES AX5-5 ..................................................................................... AX5-60

ANNEX TABLES AX5-6 ..................................................................................... AX5-75

ANNEX TABLES AX5-7 ................................................................................... AX5-111

ANNEX TABLES AX5-8 ................................................................................... AX5-121

ANNEX TABLES AX5-9 ................................................................................... AX5-146

ANNEX TABLES AX5-10 ................................................................................. AX5-156

ANNEX TABLES AX5-11 ................................................................................. AX5-186

REFERENCES .................................................................................................... AX5-190

II-vii

# List of Tables

Page

AX4-1 Analytical Methods for Determini ng Lead in Blood, Urine, and Hair ............ AX4-2

AX4-2 Summary of Selected Measurements of PbB Levels in Humans .................... AX4-4

AX4-3 Bone Lead Measurements in Cadavers............................................................ AX4-7

AX4-4 Bone Lead Measurements in Environmentally-Exposed Subjects .................. AX4-9

AX4-5 Bone Lead Measurements in Occupationally-Exposed Subjects................... AX4-12

AX4-6 Bone Lead Contribution to PbB..................................................................... AX4-19

AX4-7 Bone Lead Studies in Pregna nt and Lactating Subjects................................. AX4-22

AX4-8 Bone Lead Studies of Menopausal a nd Middle-aged to Elderly Subjects..... AX4-30

AX4-9 Lead in Deciduous Teeth from Urban and Remote Environments................ AX4-36

AX4-10 Lead in Deciduous Teeth from Polluted Environments................................. AX4-38

AX4-11 Summary of Selected Measurements of Urine Lead Levels in Humans ....... AX4-39

AX4-12 Summary of Selected Measurements of Hair Lead Levels in Humans ......... AX4-42

AX5-2.1 Effect of Lead on Erythroc yte Morphology, Mobility, and Other

Miscellaneous Parameters................................................................................ AX5-2

AX5-2.2 Lead, Erythrocyte Heme Enzy mes, and Other Parameters.............................. AX5-6

AX5-2.3 Lead Binding and Transpor t in Human Erythrocytes ...................................... AX5-9

AX5-2.4 Lead Effects on Hematological Parameters ................................................... AX5-10

AX5-2.5 Lead Interactions with Calcium Potassium in Erythrocytes .......................... AX5-12

AX5-2.6 Lead, Heme, and Cytochrome P–450 ............................................................ AX5-13

AX5-2.7 Lead, Erythrocyte Li pid Peroxidation, and Antio xidant Defense.................. AX5-14

AX5-3.1 Summary of Key Studies on Neurochemical Alterations .............................. AX5-16

AX5-3.2 Summary of Key Studies on Ne urophysiological Assessments .................... AX5-20

II-x

# List of Tables
(cont’d)

Page

AX5-3.3 Summary of Key Studies on Ch anges in Sensory Function .......................... AX5-21

AX5-3.4 Summary of Key Studies on Neurobehavioral Toxicity................................ AX5-22

AX5-3.5 Summary of Key Studies on Cell Morphology and Metal Disposition ......... AX5-31

AX5-3.6 Key Studies Evaluating Chel ation of Pb in Brain.......................................... AX5-33

AX5-4.1 Effect of Lead on Reproduction and Development in Mammals Effects
on Offspring ................................................................................................... AX5-38

AX5-4.2 Effect of Lead on Reproduction and Development in Mammals Effects

on Males......................................................................................................... AX5-45

AX5-4.3 Effect of Lead on Reproduction and Development in Mammals Effects

on Females ..................................................................................................... AX5-55

AX5-5.1 In Vivo and In Vitro Studies of the Effects of Lead Exposure on

Production and Metabolism of Reactive Oxygen Species,

Nitric Oxide, and Soluble Guanylate Cyclease.............................................. AX5-61

AX5-5.2 Studies of the Effects of Lead Exposure on PKC Activity, NF k 

# B Activation, and Apoptosis.............................................................................. AX5-66

AX5-5.3 Studies of the Effects of L ead Exposure on Blood Pressure and
Adrenergic System......................................................................................... AX5-67

AX5-5.4 Studies of the Eff ects of Lead Exposure on Renin-angiotensin System,
Kallikrein-Kinin System, Prostagl andins, Endothelin, and Atrial
NatriureticPeptide (ANP)............................................................................... AX5-69

AX5-5.5 Studies of Effect of Lead on Vascular Contractility ...................................... AX5-70

AX5-5.6 Effects of Lead on Cultured Endot helial Cell Proliferat ion, Angiogenesis,
and Production of Heparan Sulfate Proteoglycans and tPA .......................... AX5-71

AX5-5.7 Studies of the Effect of Lead on Cu ltured Vascular Smooth Muscle Cells... AX5-74

AX5-6.1 Genotoxic/Carcinogenic Effects of Lead—Laboratory Animal Studies ....... AX5-76

AX5-6.2 Genotoxic/Carcinogenic Effects of Lead—Human Cell Cultures................. AX5-78

II-xi

# List of Tables
(cont’d)

Page

AX5-6.3 Genotoxic/C arcinogenic Effect s of Lead—Carcinogenesis Animal

Cell Cultures .................................................................................................. AX5-79

AX5-6.4 Genotoxic/C arcinogenic Effects of Lead—Genotoxicity Laboratory

Animal Studies............................................................................................... AX5-81

AX5-6.5 Genotoxic/C arcinogenic Effect s of Lead—Genotoxicity Human Cell
Cultures Mutagenesis..................................................................................... AX5-85

AX5-6.6 Genotoxic/C arcinogenic Effect s of Lead—Genotoxicity Human Cell
Cultures Clastogenicity.................................................................................. AX5-86

AX5-6.7 Genotoxic/C arcinogenic Effect s of Lead—Genotoxicity Human Cell
Cultures DNA Damage .................................................................................. AX5-88

AX5-6.8 Genotoxic/C arcinogenic Effects of Lead—Genotoxicity Animal Cell
Cultures Mutagenicity.................................................................................... AX5-90

AX5-6.9 Genotoxic/C arcinogenic Effects of Lead—Genotoxicity Animal Cell
Cultures Clastogenicity.................................................................................. AX5-92

AX5-6.10 Genotoxic/C arcinogenic Effects of Lead—Genotoxicity Animal Cell
Cultures DNA Damage .................................................................................. AX5-95

AX5-6.11 Genotoxic/C arcinogenic Effects of Lead—Genotoxicity Non-mammalian

Cultures .......................................................................................................... AX5-97

AX5-6.12 Genotoxic/C arcinogenic Effects of Lead—Genotoxicity as it Pertains
to Potential Developmental Effects ............................................................... AX5-98

AX5-6.13 Genotoxic/C arcinogenic Effects of Lead—Genotoxicity as it Pertains
to Potential Developmental Effects—Children ............................................. AX5-99

AX5-6.14 Genotoxic/C arcinogenic Effects of Lead—Epigenetic Effects and Mixture

Interactions—Animal................................................................................... AX5-100

AX5-6.15 Genotoxic/C arcinogenic Effects of Lead—Epigenetic Effects and Mixture

Interactions—Human ................................................................................... AX5-101

AX5-6.16 Genotoxic/C arcinogenic Effects of Lead—Epigenetic Effects and Mixture
Interactions—DNA Repair—Human........................................................... AX5-102

II-xii

# List of Tables
(cont’d)

Page

AX5-6.17 Genotoxic/Carcinogenic Effects of Lead—Epigenetic Effects and Mixture
Interactions—DNA Repair—Animal .......................................................... AX5-103

AX5-6.18 Genotoxic/Carcinogenic Effects of Lead—Mitogenesis—Animal ............. AX5-104

AX5-6.19 Genotoxic/Carcinogenic Effect s of Lead—Mitogenesis Human and

Animal Cell Culture Studies ........................................................................ AX5-107

AX5-6.20 Genotoxic/Carcinogenic Effects of Lead—Mitogenesis Other ................... AX5-110

AX5-7.1 Light Microscopic, Ultrastructu ral, and Functional Changes...................... AX5-112

AX5-7.2 Lead and Free Radicals................................................................................ AX5-114

AX5-7.3 Chelation with DMSA ................................................................................. AX5-117

AX5-7.4 Effect of Chelator Combinations ................................................................. AX5-118

AX5-7.5 Effect of Other Metals on Lead ................................................................... AX5-119

AX5-8.1 Bone Growth in Lead-exposed Animals...................................................... AX5-122

AX5-8.2 Regulation of Bone Cell Func tion in Animals—Systemic Effects

of Lead ......................................................................................................... AX5-126

AX5-8.3 Bone Cell Cultures Utilized to Test Effects of Lead ................................... AX5-129

AX5-8.4 Bone Lead as a Potential Source of Toxicity in Altered Metabolic

Conditions .................................................................................................... AX5-136

AX5-8.5 Uptake of Lead by Teeth.............................................................................. AX5-142

AX5-8.6 Effects of Lead on Enamel and Dentin Formation ...................................... AX5-143

AX5-8.7 Effects of Lead on Dental Pulp Cells........................................................... AX5-144

AX5-8.8 Effects of Lead on Teeth—Dental Caries .................................................... AX5-145

AX5-9.1 Studies on Lead Exposure and Immune Effects in Humans........................ AX5-147

AX5-9.2 Effect of Lead on Antibody Formin g Cells (In Vitro Stimulation) ............. AX5-150

II-xiii

# List of Tables
(cont’d)

Page

AX5-9.3 Studies Reporting Lead-indu ced Suppression of Delayed Type
Hypersensitivity and Related Responses ..................................................... AX5-151

AX5-9.4 Effect of Lead on Allogeneic and Syngeneic Mixed Lymphocyte
Responses..................................................................................................... AX5-152

AX5-9.5 Effect of Lead on Mitogen-i nduced Lymphoid Proliferation ...................... AX5-153

AX5.9.6 Pattern of Lead-induced M acrophage Immunotoxicity ............................... AX5-155

AX5-10.1 Hepatic Drug Metabolism............................................................................ AX5-157

AX5-10.2 Biochemical and Molecular Perturbations in Lead-induced

Liver Tissue ................................................................................................. AX5-162

AX5-10.3 Effect of Lead Exposure on He patic Cholesterol Metabolism .................... AX5-165

AX5-10.4 Lead, Oxidative Stress, and Chelation Therapy........................................... AX5-166

AX5-10.5 Lead-induced Liver Hyperpla sia: Mediators and Molecular

Mechanisms ................................................................................................. AX5-171

AX5-10.6 Effect of Lead Exposure on Liver Heme Synthesis..................................... AX5-177

AX5-10.7 Lead and In Vitro Cytotoxici ty in Intestinal Cells....................................... AX5-180

AX5-10.8 Lead and Intestinal Uptake—E ffect on Ultrastruc ture, Motility,
Transport, and Miscellaneous ...................................................................... AX5-181

AX5-10.9 Lead, Calcium, and Vitamin D Intera ctions, and Intestinal Enzymes ......... AX5-184

AX5-11.1 Lead-binding Proteins.................................................................................. AX5-187

II-xiv

# Authors, Contributors, and Reviewers

CHAPTER 4 ANNEX (TOXICOKINETIC S, BIOLOGICAL MARKERS, AND
MODELS OF LEAD BURDEN IN HUMANS)

Chapter Managers/Editors

Dr. James Brown—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Principal Authors

Dr. Brian Gulson—Graduate School of the Environm ent, Macquarie University
Sydney, NSW 2109, Australia

Contributors and Reviewers

Dr. Lester D. Grant—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. John Vandenberg—National Center for Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

CHAPTER 5 ANNEX (TOXICOLOGICAL EFFECT S OF LEAD IN HUMANS
AND LABORATORY ANIMALS)

Chapter Managers/Editors

Dr. Anuradha Mudipalli—National Center for E nvironmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Srikanth Nadadur—National Center for Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Lori W hite—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Principal Authors

Dr. Anuradha Mudipalli—National Center for E nvironmental Assessment (B243-01),

U.S. Environmental Protection Agency, Resear ch Triangle Park, NC 27711 (Sections 5-2, 5-10)

II-xxi

# Authors, Contributors, and Reviewers

(cont’d)

Principal Authors
(cont’d)

Dr. Stephen Lasley—Dept. of Biomedical and Ther apeu tic Sciences, Univ. of Illinois College of

Medicine, PO Box 1649, Pe oria, IL 61656 (Section 5.3)

Dr. Lori White—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Re search Triangle Park, NC 27711 (Section 5.3)

Dr. Gary Diamond— Syracuse Research Co rporation, 8191 Cedar Street, Akron, NY 14001
(Section 5.4)

Dr. N.D. Vaziri—Division of Nephrology and Hype rtension, University of California – Irvine
Medical Center, 101, The City Drive, Bldg 53, Room #125. Orange, CA 92868 (Section 5.5)

Dr. John Pierce Wise, Sr.—Maine Center fo r Toxicology and Environmental Health,
Departm ent of Applied Medical Sciences, 96 Falmouth Street, PO Box 9300, Portland, ME
04104-9300 (Section 5.6)

Dr. Harvey C. Gonick—David Geffen School of Medicine, University of California at
Los Angeles, 201 Tavistock Ave, Los Angeles, CA 90049 (Sections 5.7, 5.11)

Dr. Gene E. Watson—University of Rocheste r Medical Center, Box 705, Rochester, NY 14642
(Section 5.8)

Dr. Rodney Dietert—Institute for Comparativ e and Environ mental Toxicology, College of
Veterinary Medicine, Cornell Univ ersity, Ithaca, NY 14853 (Section 5.9 )

Contributors and Reviewers

Dr. Lester D. Grant—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Paul Reinhart—Nationa l Center for Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Michael Davis—Nationa l Center for Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. David A. Lawrence—Dept of Environmental and Clinical Imm unology, Empire State Plaza

P.O. Box 509, Albany, NY 12201

II-xxii

# Authors, Contributors, and Reviewers

(cont’d)

Contributors and Reviewers
(cont’d)

Dr. Michael J. McCabe, Jr.—Dept of Environm e ntal Medicine, University of Rochester,

575 Elmwood Avenue, Rochester, NY 14642

Dr. Theodore I. Lidsky—New York State Inst itute for Basic Research, 1050 Forest RD,

Staten Island, NY 10314

Dr. Mark H. Follansbee—Syracuse Research Corporation, 8191 Cedar St. Akron, NY 14001

Dr. William K. Boyes—National Health and En v ironmental Effects Research Laboratory,

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Philip J. Bushnell—National Health and Environmental Effects Research Laboratory,

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Ms. Beth Hassett-Sipple—Office of Air Quality Planning and Standards, U.S. Environm ental
Protection Agency, Research Triangle Park, NC 27711

Dr. Zachary Pekar—Office of Air Quality Pla nning and Standards, U.S. Environm ental
Protection Agency, Research Triangle Park, NC 27711

Dr. John Vandenberg—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

CHAPTER 6 ANNEX (EPIDEMIOLOGICA L STUDIES OF AMBI ENT LEAD
EXPOSURE EFFECTS)

Chapter Managers/Editors

Dr. Jee Young Kim—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Dennis Kotchmar—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. David Svendsgaard—National Center for E nvironmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

II-xxiii

# Authors, Contributors, and Reviewers

(cont’d)

Principal Authors

Dr. David Bellinger—Children’s Hospital, Fa rley Basem ent, Box 127, 300 Longwood Avenue,
Boston, MA 02115 (Section 6.10)

Dr. Margit Bleecker—Center for Occupational and Environ mental Neurology, 2 Hamill Road,
Suite 225, Baltimore, MD 21210 (Section 6.3)

Dr. Gary Diamond— Syracuse Resear ch Corporation, 8191 Cedar Street.

Akron, NY 14001 (Section 6.8, 6.9)

Dr. Kim Dietrich—University of Cincinnati College of Medicine, 3223 E den Avenue,
Kettering Laboratory, Room G31, Cincinnati, OH 45267 (Section 6.2)

Dr. Pam Factor-Litvak—Columbia University Mailm an School of Public Health, 722 West
168th Street, Room 1614, New York, NY 10032 (Section 6.6)

Dr. Vic Hasselblad—Duke University Medica l Center, Durham, NC 27713 (Section 6.10)

Dr. Stephen J. Rothenberg—CINVESTAV-IPN, Mé rida, Yuc atán, México & National Institute
of Public Health, Cuernavaca, Morelos, Mexico (Section 6.5)

Dr. Neal Simonsen—Louisiana State University Hea lth Sciences Center, School of Public Health
& Stanley S Scott Cancer Center, 1600 Cana l Street, Suite 800, New Orleans, LA 70112
(Section 6.7)

Dr. Kyle Steenland—Rollins School of Public Health, Em ory University, 1518 Clifton Road,
Room 268, Atlanta, GA 30322 (Section 6.7)

Dr. Virginia Weaver—Johns Hopkins Bloomberg School of Public Health, 615 North W olfe
Street, Room 7041, Baltimore, MD 21205 (Section 6.4)

Contributors and Reviewers

Dr. J. Michael Davis—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Lester D . Grant—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Kazuhiko Ito—Nelson Institute of Environmental Medicine, Ne w York University School of

Medicine, Tuxedo, NY 10987

II-xxiv

# Authors, Contributors, and Reviewers

(cont’d)

Contributors and Reviewers
(cont’d)

Dr. Kathryn Mahaffey—Office of Prevention, Pesticides and Toxic Substances,

U.S. Environmental Protection Agency, Washington, DC 20460

Dr. Karen Martin—Office of Air Quality Pl anning and Standards, U.S. Environm ental Protection Agency, Research Triangle Park, NC 27711

Dr. Zachary Pekar—Office of Air Quality Pla nning and Standards, U.S. Environm ental
Protection Agency, Research Triangle Park, NC 27711

Ms. Beth Hassett-Sipple—Office of Air Quality Planning and Standards, U.S. Environm ental
Protection Agency, Research Triangle Park, NC 27711

Dr. John Vandenberg—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

CHAPTER 7 ANNEX (ENVIRONME NTAL EFFECTS OF LEAD)

Chapter Manager/Editor

Dr. Timothy Lewis—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Principle Authors

Dr. Ruth Hull—Cantox Environmental Inc., 190 0 Minnesota Court, Suite 130, Mississauga,

Ontario, L5N 3C9 Cana da (Section 7.1)

Dr. James Kaste—Department of Earth Sciences , Dartm outh College, 352 Main Street, Hanover,
NH 03755 (Section 7.1)

Dr. John Drexler—Department of Geological Sc iences, Univ ersity of Colorado, 1216 Gillespie
Drive, Boulder, CO 80305 (Section 7.1)

Dr. Chris Johnson—Department of Civil and Envir onm ental Engineering, Syracuse University,
365 Link Hall, Syracuse, NY 13244 (Section 7.1)

Dr. William Stubblefield—Parametrix, Inc. 3397 2 Texas St. SW, Albany, OR 97321
(Section 7.2)

II-xxv

# Authors, Contributors, and Reviewers

(cont’d)

Principle Authors
(cont’d)

Dr. Dwayne Moore—Cantox Environmental, Inc., 1550A Laperriere Avenue, Suite 103,
Ottawa, Ontario, K1Z 7T2 Canada (Section 7.2)

Dr. David Mayfield—Parametrix, Inc., 411 108th Ave NE, Suite 1800, Bellevue, WA 98004
(Section 7.2)

Dr. Barbara Southworth—Menzie-Cura & Associ ates, Inc., 8 W inchester Place, Suite 202,
Winchester, MA 01890 (Section 7.3)

Dr. Katherine Von Stackleberg—Menzie-Cura & A ssociates, Inc., 8 W inchester Place, Suite
202, Winchester, MA 01890 (Section 7.3)

Contributors and Reviewers

Dr. Jerome Nriagu—Department of Environmenta l Health S ciences, 109 South Observatory,
University of Michigan, Ann Arbor, MI 48109

Dr. Judith Weis—Department of Biol ogy, Rutgers University, Newark, NJ 07102

Dr. Sharon Harper—National Exposure Research Laboratory (D205-05), U.S. Environm ental
Protection Agency, Research Triangle Park, NC 27711

Dr. Karen Bradham—National Research Exposur e Laboratory (D205-05), U.S. Environm ental
Protection Agency, Research Triangle Park, NC 27711

Dr. Ginger Tennant—Of fice of Air Quality Plan ning and Standards, U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711

Ms. Gail Lacey—Office of Air Quality Planning a nd Standards, U.S. Environmental Protection
Agency, Research Triangle Park, NC 27711

Dr. John Vandenberg—National Center for Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

II-xxvi

# U.S. Environmental Protecti on Agency Project Team
for Development of Air Quality Criteria for Lead

Executive Direction

Dr. Lester D. Grant (Director)—National Cent er for Environm ental Assessment-RTP Division,
(B243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Scientific Staff

Dr. Lori White (Lead Team Leader)—Nati onal Center for E nvironmental Assessment
(B243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. James S. Brown—National Center fo r Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Robert Elias—Nationa l Center for Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Re search Triangle Park, NC 27711 (Retired)

Dr. Brooke Hemming—National Center for Environmental Assessment (B243-01), U.S.

Environm ental Protection Agency, Research Triangle Park, NC 27711

Dr. Jee Young Kim—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Dennis Kotchmar—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Timothy Lewis—National Center for Environmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Anuradha Muldipalli—National Center for E nvironmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Srikanth Nadadur—National Center for Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Paul Reinhart—Nationa l Center for Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Mary Ross— National Center for Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. David Svendsgaard—National Center for E nvironmental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

II-xxvii

# U.S. Environmental Protecti on Agency Project Team

for Dev elopment of Air Quality Criteria for Lead

(cont’d)

Technical Support Staff

Mr. Douglas B. Fennell—Technical Information Sp ecialist, National Center for Environmental

Assessm ent (B243-01), U.S. Environmental Prot ection Agency, Research Triangle Park, NC
27711 (Retired)

Ms. Emily R. Lee—Management Analyst, Natio nal Center for Environm ental Assessment
(B243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Ms. Diane H. Ray—Program Specialist, Natio nal Center for Environm ental Assessment
(B243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Ms. Donna Wicker—Administrative Officer, National Center for Environmental Assessment
(B243-01), U.S. Environm ental Protection Agenc y, Research Triangle Park, NC 27711 (Retired)

Mr. Richard Wilson—Clerk, National Center fo r Environm ental Assessment (B243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Document Production Staff

Ms. Carolyn T. Perry—Task Order Manager, Com puter Sciences Corpor ation, 2803 Slater Road,

Suite 220, Morrisville, NC 27560

Mr. John A. Bennett—Technical Information Sp ecialist, Library Asso ciates of Maryland,

11820 Parklawn Drive, Suite 400, R ockville, MD 20852

Mr. William Ellis—Records Management Technician, InfoPro, Inc., 8200 Greensboro Drive,

Suite 1450, McLean, VA 22102

Ms. Sandra L. Hughey—Technical Information Sp ecialist, Library Associates of Maryland,

11820 Parklawn Drive, Suite 400, R ockville, MD 20852

Dr. Barbara Liljequist—Technical Editor, Comp uter Sciences Corporation, 2803 Slater Road,

Suite 220, Morrisville, NC 27560

Ms. Michelle Partridge-Doerr—Publications/Gra phics Specialist, TEK System s, 1201 Edwards
Mill Road, Suite 201, Raleigh, NC 27607

Mr. Carlton Witherspoon—Graphic Artist, Comput er Sciences Corporation, 2803 Slater Road,

Suite 220, Morrisville, NC 27560

II-xxviii

# U.S. Environmental Protection Agency
Science Advisory Board (SAB) Staff Office

Clean Air Scientific Advi sory Committee ( CASAC)

Chair

Dr. Rogene Henderson*—Scientist Emeritus, Lovelace Respiratory Research Institute,
Albuquerque, NM

Members

Dr. Joshua Cohen—Faculty, Center for the Evaluati on of Value and Risk, Institute for Clinical
Research and Health Policy Studies, Tuft s New England Medical Center, Boston, MA

Dr. Deborah Cory-Slechta—Director, University of Medicine and Dentistry of New Je rsey and
Rutgers State University, Piscataway, NJ

Dr. Ellis Cowling*—University Distinguished Professor-at-L arge, North Carolina State
University, Colleges of Natural Resources and Agriculture and Life Sciences, North Carolina
State University, Raleigh, NC

Dr. James D. Crapo [M.D.]*—Professor, Departme nt of Me dicine, National Jewish Medical and

Research Center, Denver, CO

Dr. Bruce Fowler—Assistant Director for Scien ce, Division of Toxicology and Environm ental Medicine, Office of the Director, Agency for Toxic Substances and Disease Registry, U.S.

Centers for Disease Control and Pr evention (ATSDR/CDC), Chamblee, GA

Dr. Andrew Friedland—Professo r and Chair, Environmental Studies Program, Dartmouth
College, Hanover, NH

Dr. Robert Goyer [M.D.]—Emeritu s Professor of Pathology, Faculty of Medicine, University of
Western Ontario (Canada), Chapel Hill, NC

Mr. Sean Hays—President, Summ it Toxicology, Allenspark, CO

Dr. Bruce Lanphear [M.D.]—Sloan Professor of Children’s E nvironmental Health, and the

Director of the Cincinnati Ch ildren’s Environmental Health Ce nter at Cincinnati Children’s
Hospital Medical Center and the Univer sity of Cincinnati, Cincinnati, OH

Dr. Samuel Luoma—Senior Research Hydr ologist, U.S. Geological Survey (USGS),

Menlo Park, CA

II-xxix

# U.S. Environmental Protection Agency
Science Advisory Board (SAB) Staff Office

Clean Air Scientific Advi sory Committee ( CASAC)

(cont’d)

Members
(cont’d)

Dr. Frederick J. Miller*—Consultant, Cary, NC

Dr. Paul Mushak—Principal, PB A ssociates, and Visiting P rofessor, Albert Einstein College of
Medicine (New York, NY), Durham, NC

Dr. Michael Newman—Professor of Marine Science, School of Marine S ciences, Virginia
Institute of Marine Science, College of William & Mary, Gloucester Point, VA

Mr. Richard L. Poirot*—Environmental Analyst, Air Pollution Control Di vision, Departm ent of
Environmental Conservation, Vermont Agency of Natural Resources, Waterbury, VT

Dr. Michael Rabinowitz—Geochemist, Marine B iological Laboratory, Woods Hole, MA

Dr. Joel Schwartz—Professor, Environmental H ealth, Harvard University School of Public

Health, Boston, MA

Dr. Frank Speizer [M.D.]*—Edward Kass Professo r of Medicine, Channing Laboratory, Harvard

Medical School, Boston, MA

Dr. Ian von Lindern—Senior Scientist, TerraG raphics Environm enta l Engineering, Inc.,

Moscow, ID

Dr. Barbara Zielinska*—Research Professor, Divi sion of Atmospheric S cience, Desert Research

Institute, Reno, NV

SCIENCE ADVISORY BOARD STAFF

Mr. Fred Butterfield—CASAC Designated Fede ral Officer, 1200 Pennsyl vania Avenue, N.W

., Washington, DC, 20460, Phone: 202-343-9994, Fax: 202-233-0643 (butterfield.fred@epa.gov ) (Physical/Courier/FedEx Address: Fred A. Butterf ield, III, EPA Science Advisory Board Staff
Office (Mail Code 1400F), Woodies Building, 1025 F Street, N.W., Room 3604, Washington,
DC 20004, Telephone: 202-343-9994)

*Members of the statutory Clean Air Scientific Advisory Committee (CASAC) appointed by the

U.S. EPA Administrator



# II-xxx

# Abbreviations and Acronyms

α FGF α -fibroblast growth factor

AA arachidonic acid

AAL active avoidance learning

AAS atomic absorption spectroscopy

ABA β -aminoisobutyric acid

ACBP Achenbach Child Behavior Profile

ACE angiotensin converting enzyme

ACh acetylcholine

AChE acetylcholinesterase

ACR acute-chronic ratio

AD adult

ADC analog digital converter

ADP adenosine diphosphate

AE anion exchange

AEA N -arachidonylethanolamine

AFC antibody forming cells

2-AG 2-arachidonylglycerol

A horizon uppermost layer of soil (litter and humus)

AHR aryl hydrocarbon receptor

AI angiotensin I

ALA * -aminolevulinic acid

ALAD * -aminolevulinic acid dehydratase

ALAS aminolevulinic acid synthetase

ALAU urinary δ -aminolevulinic acid

ALD aldosterone

ALS amyotrophic lateral sclerosis

ALT alanine aminotransferase

ALWT albumin weight

AMEM Alpha Minimal Essential Medium

AMP adenosine monophosphate

ANCOVA analysis of covariance

ANF atrial natriuretic factor

Ang II angiotensin II

ANOVA analysis of variance

II-xxxi

# ANP atrial natriuretic peptide

AP alkaline phosphatase

AP-1 activated protein-1

ApoE apolipoprotein E

AQCD Air Quality Criteria Document

Arg arginine

AS52 cells derived from the CHO cell line

ASGP-R aceyl glycoprotein receptor

AST aspartate aminotransferase

ASV anode stripping voltammetry

3-AT 3-aminotriazole; 3-amino triazide

ATP adenosine triphosphate

ATP1A2 sodium-potassium adenosine triphosphase α 2

ATPase adenosine triphosphatase

ATSDR Agency for Toxic Substances and Disease Research

AVCD atrioventricular conduction deficit

AVS acid volatile sulfide

AWQC ambient water quality criteria

$ beta-coefficient; slope of an equation

$ FGF $ -fibroblast growth factor

17 $ –HS 17 $ -hydroxysteriod

3 $ -HSD 3 $ -hydroxysteriod dehydrogenase

17 $ -HSDH 17 $ -hydroxysteriod dehydrogenase

6 $ -OH-cortisol 6- $ -hydroxycortisol

B both

BAEP brainstem auditory-evoked potentials

BAER brainstem audito ry-evoked responses

BAF bioaccumulation factor

B cell B lymphocyte

BCFs bioconcentration factors

BCS bovine calf serum

BDNF brain derived neurotrophic factor

BDWT body weight changes

BEI biological exposure index

BFU-E blood erythroid progenitor

II-xxxii

# BLL blood lead level

BLM biotic ligand m odel

BM basement mem brane

BMI body m ass index

BDNF brain-derived ne urotrophic factor

BOTMP Bruinicks-Oseretsky Test of Motor Proficiency

BP blood pressure

BPb blood lead concentration

BSA bovine serum albumin

BSI Brief Symptom Inventory

BTQ Boston Teacher Questionnaire

BUN blood urea nitrogen

bw, b. wt., BW body weight

C3H10T/12 mouse embryo cell line

C3, C4 complement proteins

CA chromosome aberration

CA3 cornu ammonis 3 region of hippocampus

45 

# Ca calcium-45 radionuclide

Ca-ATP calcium-dependent adenosine triphosphate

Ca-ATPase calcium-dependent adenosine triphosphatase

CaCO 3 

# calcium carbonate

CaEDTA calcium disodium ethylenediaminetetraacetic acid

CAL calcitonin

CaM calmodulin

Ca-Mg-ATPase calcium-magnesium-dependent adenosine triphosphatase

cAMP cyclic adenosinem onophosphate

CaNa 2 

# EDTA calcium disodium ethyl enediam inetetraacetic acid

CANTAB Cambridge Neuropsychologi ca l Testing Automated Battery

CAT catalase; Cognitive Abilities Test

CBCL Achenbach Child Behavior Checklist

CBCL-T Total Behavior Problem Score

CBL cumulative blood lead

CBLI cumulative blood lead index

CCB cytochalasin B

CCD charge-coupled device

II-xxxiii

# CCE Coordination Center for Effects

CCL carbon tetrachloride

CCS cosmic calf serum

C-CV RSA 

# coefficient of component va riance of respiratory sinus
arrhythmia

Cd cadm ium

109 

# Cd cadmium-109 radionuclide

CdU urinary cadmium

CEC cation exchange capacity

CESD, CES-D Center for Epidemio logic Studies Depression (scale)

GFAP glial fibrillary acidic protein

CFU-E colony forming unit blood-er ythroid progenitor (cell count)

CFU-GEMM colony forming unit blood- pluripotent progen itor (cell count)

CFU-GM blood granulocyte/macro phage progenitor (cell count)

cGMP cyclic guanosine-3',5'-monophosphate

ChAT choline acetyltransferase

CHD coronary heart disease

CHO Chinese hamster ovary cell line

CI confidence interval

CLE-SV competitive ligand-exchange/stripping voltammetry

CLRTAP Convention on Long-Range Transboundary of Air Pollution

CLS Cincinnati Lead Study

CMC criterion maximum concentration

CMI cell-mediated immunity

CNS central nervous system

COH cation-osmotic hemolysis

ConA concanavalin A

COR cortisol

CoTx cotreatment

COX-2 cyclooxygenase-2

CP coproporphryn

CPT current perception threshold

cr creatinine

CRAC calcium release activated calcium reflux

CREB cyclic AMP-response element binding protein

CRF chronic renal failure

II-xxxiv

# CV CRI chronic renal insufficien cy

CSF cerebrospinal fluid

CuZn-SOD copper and zinc-dependent superoxide dismutase

conduction velocity

CVLT California V erbal Learning Test

CV R-R 

# coefficient of variation of the R-R interval

CYP cytochrome (e.g., CYP1A, CYP-2A6, CYP3A4, CYP450)

CYP3a11 cytochrome P450 3a11

D D-statistic

DA dopamine; dopaminergic

dbcAMP dibutyryl cyclic ad enosine-3',5'-monophosphate

DCV distribution of conduction velocities

DEAE diethylaminoet hyl (chromatography)

DET diffusive equilibrium thin films

DEYO death of young

DFS decayed or filled surfaces, permanent teeth

dfs covariate-adjusted number of caries

DG dentate gyrus

DGT diffusive gradient thin films

DL DL-statistic

DMEM Dulbecco’s Minimal Essential Medium

DMEM/F12 Dulbecco’s Minimal Essential Medium/Ham’s F12

DMFS decayed, missing, or filled surfaces, permanent teeth

DMPS 2,3-dimercaptopropane 1-sulfonate

DMSA 2,3-dimercaptosuccinic acid

DMT Donnan membrane technique

DMTU dimethylthiourea

DNA deoxyribonucleic acid

DO distraction osteogenesis

DOC dissolved organic carbon

DOM dissolved organic carbon

DOPAc 3,4-dihydroxyphenylacetic acid

DPASV differential pulse anod ic stripping voltammetry

dp/dt rate of left ventri cular isovolumetric pressure

DPPD N

- N -diphenyl- p -phynylene-diamine

II-xxxv

# DR drinking water

DSA delayed spatial alternation

DTC diethyl dithiocarbomate complex

DTH delayed type hypersensitivity

DTPA diethylenetriaminepentaacetic acid

DTT dithiothreitol

dw dry weight

E embryonic day

E 2 

# estradiol

EBE early biological effect

EBV Epstein-Barr virus

EC European Community

EC 50 

# effect concentration fo r 50% of test population

eCB endocannabinoid

ECG electrocardiogram

Eco-SSL ecological soil screening level

EDS energy dispersive spectrometers

EDTA ethylenediaminetetraacetic acid

EEDQ N -ethoxycarbonyl-2-eth oxy-1,2-dihydroquinone

EEG electroencephalogram

EG egg

EGF epidermal growth factor

EGG effects on eggs

EGPN egg production

EKG electrocardiogram

electro electrophysiological stimulation

EM/CM experimental medium-to-control medium (ratio)

EMEM Eagle’s Minimal Essential Medium

eNOS endothelial nitr ic oxide synthase

EP erythrocyte protoporphyrin

EPA U.S. Environmental Protection Agency

Epi epinephrine

EPMA electron probe microanalysis

EPO erythropoietin

EPSC excitatory postsynaptic currents

II-xxxvi

# EPT macroinvertebrates from the Ephemeroptera (mayflies),
Plecoptera (stoneflies), and Trichoptera (caddisflies) group

ERG electroretinogram ; electroretinographic

ERL effects rang e – low

ERM effects rang e – median

EROD ethoxyresorufin- O -deethylase

ESCA electron spectroscopy for chem ical analysis

ESRD end-stag e renal disease

EST estrad iol

ESTH eggshell thinning

ET endothelein; essential tremor

ETOH ethyl alcohol

EXAFS extended X-ray absorption fine structure

EXANES extended X-ray absorp tion near edge spectroscopy

F F-statistic

F344 Fischer 344 (rat)

FAV f inal acute value

FBS fetal bovine serum

FCS f etal calf serum

FCV final chronic value

FD food

FEF forced expiratory flow

FEP free erythrocyte protoporphyrin

FERT f ertility

FEV 1 

# forced expiratory volume in one second

FGF fibroblast growth factor (e.g., β FGF, α FGF)

FI f ixed interval (operant conditioning)

FIAM free ion activity m odel

FMLP N -for myl-L-methionyl-L-l eucyl-L-phenylalanine

fMRI functional m agnetic resonance imaging

FR fixed-ratio operant conditioning

FSH f ollicle stimulating hormone

FT3 free triiodothyronine

FT4 free thyroxine

FTES free testosterone

II-xxxvii

# FTII Fagan Test of Infant Intelligence

FTPLM flow-through permeation liquid membranes

FURA-2 1-[6-amino-2-(5-carboxy- 2-oxazolyl)-5-benzofuranyloxy]-2-
(2-amino-5-methylphenoxy) ethane- N

, N

, N'

, N' -tetraacetic acid

FVC forced vital capacity

( -GT ( -glutamyl transferase

G gestational day

GABA gamma aminobutyric acid

GAG glycosaminoglycan

G12 CHV79 cells derived from the V79 cell line

GCI General Cognitive Index

GD gestational day

GDP guanosine diphosphate

GEE generalized estimating equations

GFAAS graphite furnace atomic absorption spectroscopy

GFR glomerular filtration rate

GGT ( -glutamyl transferase

GH growth hormone

GI gastrointestinal

GIME-VIP gel integrated microelect rodes combined with voltammetric
in situ profiling

GIS geographic infor mation system

GLU glutamate

GMAV genus mean acute value

GMCV genus mean chronic value

GMP guanosine monophosphate

GMPH general morphology

GnRH gonadotropin releasing hormone

GOT aspartate aminotransferase

GP gross productivity

G6PD, G6PDH glucose-6- phosphate dehydrogenase

GPEI glutathione S -transferase P enhancer element

gp91 phox 

# NAD(P)H oxidase

GPT glutamic-pyruvic transaminase

GPx glutathione peroxidase

GRO growth

II-xxxviii

# GRP78 glucose-regulated protein 78

GSD geometric standard deviation

GSH reduced glutathione

GSIM gill surface interaction model

GSSG glutathione disulfide

GST glutathione- S -transferase

GSTP placental glutathione transferase

GTP guanosine triphosphate

GV gavage

H + 

# acidity

3 

# H hydrogen-3 radionuclide (tritium)

HA humic acid; hydroxyapatite

Hb hemoglobin

HBEF Hubbard Brook Experimenatl Forest

HBSS Hank’s Balanced Salt Solution

HCG; hCG human chorionic gonadotropin

Hct hematocrit

HDL high-density lipopr otein (cholesterol)

HEP habitat evaluation procedure

HET Binghamton heterogeneous stock

HFPLM hollow fiber permeation liquid membranes

Hgb hemoglobin

HGF hepatocyte growth factor

HH hydroxylamine hydrochloride

H-H high-high

HHANES Hispanic Health and Nutrition Examination Survey

H-L high-low

HLA human leukocyte antigen

H-MEM minimum essential medium/nutrient mixture–F12-Ham

HMP hexose monophosphate shunt pathway

HNO 3 

# nitric acid

H 2 

# O 2 

# hydrogen peroxide

HOME Home Observation for Measurement of Environment

HOS TE human osteosarcoma cells

HPLC high-pressure liquid chromatography

II-xxxix

# H 3 

# PO 4 

# phosphoric acid

HPRT hypoxanthine phosphoribosyltransferase (gene)

HR heart rate

HSI habitat suitability indices

H 2 

# SO 4 

# sulfuric acid

HSPG heparan sulfate proteoglycan

Ht hematocrit

HTC hepatoma cells

hTERT catalytic subunit of human telomerase

HTN hypertension

IBL integrated blood lead index

IBL H WRAT-R integrated blood lead index H Wide Range Achievement

Test-Revised (interaction)

ICD Intern ational Classification of Diseases

ICP inductively coupled plasma

ICP-AES inductively coupled plas ma atomic emission spectroscopy

ICP-MS, ICPMS inductively coupl ed plasma mass spectrometry

ID-MS isotope dilution mass spectrometry

IFN interferon (e.g., IFN- ( )

Ig immunoglobulin (e.g., IgA, IgE, IgG, IgM)

IGF-1 insulin-like growth factor 1

IL interleukin (e.g., IL-1, IL-1 $ , IL-4, IL-6, IL-12)

ILL incipient lethal level

immuno immunohistochemical staining

IMP inosine monophosphate

iNOS inducible nitric oxide synthase

i.p., IP intraperitoneal

IPSC inhibitory postsynaptic currents

IQ intelligence quotient

IRT interresponse time

ISEL in situ end labeling

ISI interstimulus interval

i.v., IV intravenous

IVCD intraventricular conduction deficit

JV juvenile

II-xl

# KABC Kaufman Assessment Battery for Children

KTEA Kaufman Test of Educational Achievement

KXRF, K-XRF K-shell X-ray fluorescence

LA lipoic acid

LB laying bird

LC lactation

LC 50 

# lethal concentration at which 50% of exposed animals die

LC 74 

# lethal concentration at which 74% of exposed animals die

LD 50 

# lethal dose at which 50% of exposed animals die

LDH lactate dehydrogenase

LDL low-density lipoprotein (cholesterol)

L-dopa 3,4-dihydroxyphenylalanine (precursor of dopamine)

LE Long Evans (rat)

LET linear energy transfer (radiation)

LH luteinizing hormone

LHRH luteinizing hormone releasing hormone

LN lead nitrate

L-NAME L- N G 

# -nitroarginine methyl ester

LOAEL lowest-observed adverse effect level

LOEC lowest-observed-effect concentration

LOWESS locally weighted scatter plot smoother

LPO lipoperoxide

LPP lipid peroxidation potential

LPS lipopolysaccharide

LT leukotriene

LT 50 

# time to kill 50%

LTER Long-Term Ecological Research (sites)

LTP long term potentiation

LVH left ventricular hypertrophy

μPIXE microfocused particle induced X-ray emission

μSXRF microfocused synchrotron-based X-ray fluorescence

MA mature

MA-10 mouse Leydig tumor cell line

MANCOVA multivariate analysis of covariance

MAO monoamine oxidase

II-xli

# MATC maximum acceptable threshold concentration

MDA malondialdehyde

MDA-TBA malondialdehyde-thiobarbituric acid

MDCK kidney epithelial cell line

MDI Mental Development Index (score)

MDRD Modification of Diet in Renal Disease (study)

MEM Minimal Essential Medium

MG microglobulin

Mg-ATPase magnesium-dependent adenosine triphosphatase

MiADMSA monoisamyl dimercaptosuccinic acid

Mi-DMSA mi monoisoamyl dimercaptosuccinic acid

MK-801 NMDA receptor antagonist

MLR mixed lymphocyte response

MMSE Mini-Mental State Examination

MMTV murine mammary tumor virus

MN micronuclei formation

MND motor neuron disease

MNNG N -methyl- N' -nitro- N -nitrosoguanidine

MPH morphology

MRI magnetic resonance imaging

mRNA messenger ribonucleic acid

MROD methoxyresorufin- O -demethylase

MRS magnetic resonance spectroscopy

MS mass spectrometry

MSCA McCarthy Scales of Children’s Abiltities

mSQGQs mean sediment quality guideline quotients

MT metallothionein

MVV maximum voluntary ventilation

MW molecular weight (e.g., high-MW, low-MW)

N, n number of observations

N/A not available

NAAQS National Ambient Air Quality Standards

NAC N -acetyl cysteine

NAD nicotinamide adenine dinucleotide

NADH reduced nicotinamide adenine dinucleotide

II-xlii

# NADP nicotinamide adenine dinucleotide phosphate

NAD(P)H, NADPH reduced nicotinamide adenine dinucleotide phosphate

NADS nicotinamide adenine dinucleotide synthase

NAF nafenopin

NAG N -acety l- $ -D-glucosaminidase

Na-K-ATPase sodium-potassium-dep endent adenosine triphosphatase

NAWQA National W ater-Quality Assessment

NBT nitro blue tetrazolium

NCBP National Contaminant Biomonitoring Program

NCD nuclear chromatin decondensation (rate)

NCS newborn calf serum

NCTB Neurobehavioral Core Test Battery

NCV nerve conduction velocity

ND non-detectable; not detected

NDI nuclear divison index

NE norepinephrine

NES Neurobehavioral Evaluation System

NF- κ B nuclear transcription factor- κ B

NGF nerve growth factor

NHANES National Health and Nutrition Examination Survey

NIOSH National Institute for Occupational Safety and Health

NIST National Institute for Standards and Technology

NK natural kille r

NMDA N -m ethyl-D-aspartate

NMDAR N -m ethyl-D-aspartate receptor

NMR nuclear m agnetic resonance

NO nitric oxide

NO 2 

# nitrogen dioxide

NO 3 

# nitrate

NOAEC no-observed-adverse- effect concentration

NOAEL no-observed-adverse-effect level

NOEC no-observed-effect concentration

NOEL no-observed-effect level

NOM natural organic matter

NORs nucleolar organizing regions

II-xliii

# NOS nitric oxide synthase ; not otherwise specified

NO

x 

# nitrogen oxides

NP net productivity

NPSH nonprotein sulfhydryl

NR not reported

NRC National Research Council

NRK normal rat kidney

NS nonsignificant

NSAID non-steroidal anti-inflammatory agent

NT neurotrophin

NTA nitrilotriacetic ac id

O 2 

# oxygen

ODVP offspring developm ent

OH hydroxyl

7-OH-coumarin 7-hydroxy-coumarin

1,25-(OH) 2 

# -D, 1,25-(OH) 2 

# D 3 

# 1,25-dihydroxyvitamin D

24,25-(OH) 2 

# -D 3 

# 24,25-dihydroxyvitamin D

25-OH-D 3 

# 25-hydroxyvitamin D

8-OHdG 8-hydroxy-2'-deoxyguanosine

O horizon forest floor

OR odds ratio; other oral

OSWER Office of Solid Waste and Emergency Response

P, p probability value

P300 event-related potential

P450 1A1 cytochrome P450 1A1

P450 1A2 cytochrome P450 1A2

P450 CYP3a11 cytochrome P450 3a11

PAD peripheral arterial d isease

PAH polycyclic aromatic hydrocarbon

PAI-1 plasminogen activator inhibitor-1

PAR population attributable risk

Pb lead

203 

# Pb lead-203 radionuclide

204 

# Pb, 206 

# Pb, 207 

# Pb, 208 

# Pb stable isotopes of lead-204, -206, -207, -208, respectively

210 

# Pb lead-210 radionuclide

II-xliv

# Pb(Ac) 2 

# lead acetate

PbB blood lead concentration

PbCl 2 

# lead chloride

Pb(ClO 4 

# ) 2 

# lead chlorate

PBG-S porphobilinogen synthase

PBMC peripheral bl ood mononuclear cells

Pb(NO 3 

# ) 2 

# lead nitrate

PbO lead oxides (or litharge)

PBP progressive bulbar paresis

PbS galena

PbU urinary lead

PC12 pheochromocytoma cell

PCR polymerase chain reaction

PCV packed cell volume

PDE phosphodiesterase

PDGF platelet-derived growth factor

PDI Psychomotor Development Index

PEC probable effect concentration

PEF expiratory peak flow

PG prostaglandin (e.g., PGE 2 

# , PGF 2 

# ); prostate gland

PHA phytohemagglutinin A

Pi inorganic phosphate

PIXE particle induced X-ray emission

PKC protein kinase C

pl NEpi plasma norepinephrine

PMA progressive muscular atrophy

PMN polymorphonuclear leucocyte

PMR proportionate mortality ratio

PN postnatal (day)

P5N pyrimidine 5'-nucleotidase

PND postnatal day

p.o., PO per os (oral administration)

POMS Profile of Mood States

ppb parts per billion

ppm parts per million

II-xlv

# PPVT-R Peabody Picture Vocabulary Test-Revised

PRA plasma renin activity

PRL prolactin

PROG progeny counts or numbers

PRR prevalence rate ratio

PRWT progeny weight

PST percent transferrin saturation

PTH parathyroid hormone

PTHrP parathyroid hor mone-related protein

PVC polyvinyl chloride

PWM pokeweed mitogen

PRWT progeny weight

QA/QC quality assura nce/quality control

Q/V flux of air (Q) divided by volume of culture (V)

r Pearson correlation coefficient

R 2 

# multiple correlation coefficient

2 

# r correlation coefficient

226 

# Ra most stable isotope of radium

R/ALAD ratio of ALAD activity be fore and after reactivation

RAVLT Rey Auditory Verbal Learning Test

86 

# Rb rubidium-86 radionuclide

RBA relative bioavailablity

RBC red blood cell; erythrocyte

RBF renal blood flow

RBP retinol binding protein

RBPH reproductive behavior

RCPM Ravens Colored Progressive Matrices

REL rat epithelial (cells)

REP reproduction

RHIS reproductive organ histology

222 

# Rn most stable isotope of radon

RNA ribonucleic acid

ROS reactive oxygen species

ROS 17.2.8 rat osteosarcoma cell line

RPMI 1640 Roswell Park Memorial In stitute basic cell culture medium

II-xlvi

# RR

RT

RSEM

RSUC

RT

∑ SEM

SA7

SAB

SAM

SBIS-4

s.c., SC

SCAN

SCE

SCP

SD

SDH

SDS

SE

SEM

SES

sGC

SH

SHBG

SHE

SIMS

SIR

SLP

SM

SMAV

SMR

SNAP

SNP

SO 2



# SOD relative risk; rate ratio

reaction time

resorbed embryos

reproductive success (general)

reproductive tissue

sum of the molar concentrations of simultaneously extracted

metal

sim ian adenovirus

Science Advisory Board

S -adenosyl-L-methionine

Stanford-Binet Intelligence Scale-4th edition

subcutaneous

Test for Auditory Processing Disorders

selective chemical extraction; sister chromatid exchange

stripping chronopotentiometry

Spraque-Dawley (rat); standard deviation

succinic acid dehydrogenase

sodium dodecyl sulfate; Symbol Digit Substitution

standard error; standard estimation

standard error of the mean

socioeconomic status

soluble guanylate cyclase

sulfhydryl

sex hormone binding globulin

Syrian hamster embryo cell line

secondary ion mass spectrometry

standardized incidence ratio

synthetic leaching procedure

sexually mature

species mean acute value

standardized mortality ratio

Schneider Neonatal Assessment for Primates

sodium nitroprusside

sulfur dioxide

superoxide dismutase

II-xlvii

# SOPR sperm-oocyte penetration rate

SPCL sperm cell counts

SPCV sperm cell viability

SQGs sediment quality guidelines

SRA Self Reported Antisocial Behavior scale

SRD Self Report of Delinquent Behavior

SRIF somatostatin

SRM Standard Reference Material

SRT simple reaction time

SSADMF Social Security Admini stration Death Master File

SSB single-strand breaks

SSEP somatosensory-evoked potential

StAR steroidogenic acute regulatory protein

STORET STOrage and RETrieval

SVC sensory conduction velocity

SVRT simple visual reaction time

T testosterone

TA tail

TABL time-averaged blood lead

T&E threatened and endangered (species)

TAT tyrosine aminotransferase

TB tibia

TBARS thiobarbituric acid-reactive species

TBPS Total Behavior Problem Score

TCDD methionine-choline-deficient diet

T cell T lymphocyte

TCLP toxic characteristic leaching procedure

TE testes

TEC threshold effect concentration

TEDG testes degeneration

TEL tetraethyl lead

TES testosterone

TEWT testes weight

TF transferrin, translocation factor

TG 6-thioguanine

II-xlviii

# TGF transforming growth factor

TH tyrosine hydroxylase

232 

# Th stable isotope of thorium-232

TLC Treatment of Lead-exposed Children (study)

TNF tumor necrosis factor (e.g., TNF- α )

TOF time-of-flight

tPA plasminogen activator

TPRD total production

TRH thyroid releasing hormone

TRV toxicity reference value

TSH thyroid stimulating hormone

TSP triple-super phosphate

TT3 total triiodothyronine

TT4 serum total thyroxine

TTES total testosterone

TTR transthyretin

TU toxic unit

TWA time-weighted average

TX trom boxane (e.g., TXB 2 

# )

U uriniary

235 

# U, 238 

# U uranium-234 and -238 radionuclides

UCP urinary coproporphyrin

UDP uridine diphosphate

UNECE United Nations Economic Comm ission for Europe

Ur urinary

USFWS U.S. Fish and Wildlife Service

USGS United States Geological Survey

UV ultraviolet

V79 Chinese hamster lung cell line

VA Veterans Administration

VC vital capacity; vitamin C

VDR vitamin D receptor

VE vitamin E

VEP visual-evoked potential

variable-interval

II-xlix VI

# vit C vitamin C

vit E vitamin E

VMA vanilmandelic acid

VMI Visual-Motor Integration

VSM vascular smooth muscle (cells)

VSMC vascular smooth muscle cells

WAIS Wechsler Adult Intelligence Scale

WDS wavelength dispersive spectrometers

WHO World Health Organization

WISC Wechsler Intelligence Scale for Children

WISC-R Wechsler Intelligence Scale for Children-Revised

WO whole organism

WRAT-R Wide Range Achievement Test-Revised

WT wild type

WTHBF-6 human liver cell line

ww wet weight

XAFS X-ray absorption fine structure

XANES X-ray absorption near edge spectroscopy

XAS X-ray absorption spectroscopy

XPS X-ray photoelectron spectroscopy

X-rays synchrotron radiation

XRD X-ray diffraction

XRF X-ray fluorescence

ZAF correction in reference to thre e components of matrix effects:
atomic number (Z), absorpti on (A), and fluorescence (F)

ZnNa 2 

# DTPA zinc disodium diet hylenetriaminepentaacetic acid

ZnNa 2 

# EDTA zinc disodium ethyl enediaminetetraacetic acid

ZPP zinc protoporphyrin

II-l

# AX5-1 

# AX5. 

# CHAPTER 5 ANNEX

ANNEX TABLES AX5-2

# AX5-2Table AX5-2.1. Effect of Lead onErythrocyte Morphology, Mobility, and Other Miscellaneous ParametersDose and Route ofExposureDuration Species BloodleadEffectAuthorsPb nitrate0–100 μM,Free Pb2+0–20 μM,In vitro(a) Pb recoverystudies,10 min(b) Relationshipof free Pb2+toadded Pb,20 minErythrocyte cell lysates fromhumans— Uptake and transport of Pb in erythrocyte and across erythrocyte cellmembrane under the influence ofvarying buffers and ions.a. Pb can cross the membrane passively in either direction.Influx and efflux show similar propertiesb. Passive transport of Pb is strongly stimulated by HCO3!(bicarbonate)c. Pb uptake is unaffected by varying the external concentrations ofNa+, K+, and Ca2+d. In RBC, Pb binds mainly tohemoglobin. The ratio of bound Pbto free Pb2+in the cytosol is estimated 6000:1Simons (1986a)Pb nitrate1.5 mMIn vitro1 hHuman erythrocytes— Pb uptake and transport are studied in resealed erythrocyte ghosts.a. Transport of Pb across erythrocyte membranes is passiveb. 90% of Pb uptake by erythrocytes is inhibited by drugs that blockanion transport, indicating theinvolvement of anion exchangesc. Pb transport depends upon the presence of a second anion. In thepresence of HCO3!, the rate is stimulated in the order of ClO4!<NO3!and CH3CO2!<F!<Cl!<Br!<I!Simons (1986b)10 μM Pb,as Pb acetate,In vitro20 minErythrocyte ghosts andunsealed erythrocytes— In erythrocytes, the anion exchange mechanisms and internal thiolgroups are critical factors thataffect the stimulation of aCa2+-dependent process by Pb2+.Lal et al. (1996)1 h Plasma Pb uptake was at the rate of 0.17 μ moles/h.100 μg/dL Pb,10 mg/dL, Pb,In vitro24 hHuman erythrocytes—Uptake comparable in erythrocyte ghosts and in intact cells.No association of Pb with membranes at 24 h.Sugawara et al.(1990)0–1 hMDCK Kidney epithelial cellline, In vitro2 μM Pb acetate2 μM Pb0–2 hHuman erythrocytes, in vitro— Anion exchange (AE) plays a critical role in regulating intracellularpH in erythrocytes and epithelial cells and facilitates Pb uptake.Bannon et al. (2000)10 or 20 mM Pbacetate, i.p. once aweek (100 or200 μmoles)/ kg b.wt.5 wksAlbino ratsControl:1-12 μg/100 mLExposed:100-800 μg/dLExposure to Pb significantly decreased the erythrocyte mobility.The decreases in mobility were either simultaneous or prior to thedecreases in hemoglobin (Hb) or hematocrit (Ht). In exposed rats, asignificant negative correlation was found between mobility andblood Pb levels. Decreases in ALAD (*-aminolevulinic acid), wasalso apparent in exposed animals.Terayama et al.(1986)

# AX5-3Table AX5-2.1 (cont’d). Effect of Lead on Erythrocyte Morphology, Mobility, and Other Miscellaneous ParametersDose and Route ofExposureDuration Species BloodleadEffectAuthors20 mM Pb acetate,i.p. once a week(200 μmoles/kg b.wt)5 wksMaleWistar Albino ratsControl:1–12 μg/100 mLExposed:100–800:g/dLExposure to Pb significantly decreased RBC membrane sialic acidcontent, erythrocyte survival, hemoglobin, and hematocrit. This wasevident to a minor extent below blood Pb levels 100 μg/100 mL andwas generally present from 100 μg/100 mL and higher.Terayama andMuratsuga (1988)200 μM of Pb acetate,i.p.Once a week for5 wksRat 0–600 μg/dL Pb exposure significantly decreases RBC count, Hb values,hematocrit, mean corpuscular volume, and mean corpuscularhemoglobin, decreases erythrocyte mobility, membrane sialic acidcontent, and deformability.Terayama (1993)Pb, i.p. 20 mg/ kgb.wt.14 consecutivedaysMaleAlbino ratAcetyl choline esterase (AchE), NADH dehydrogenase, and Na+-K+ATPase activities in rat erythrocyte membranes were inhibited by Pbexposure. Erythrocyte membrane sialic acid, hexose, hexosaminewere inhibited by Pb exposure. Membrane phospholipids andcholesterol were increased.Jehan and Motlag(1995)1 μM Pb nitrate 1 hErythrocytes from Pb-exposedhealthy humansControls:8.3 μg/dLExposed:70.5 μg/dLPb exposure in healthy human RBCmembranes resulted in increasedlevels of arachidonic acid (AA). The increase in AA correlated in adose dependent manner with elevation in Pb and with serum iron.On the other hand, a negative correlation was found between Aa andserum calcium. It is inferred that substitution of Pb to calcium,which is essential for the release of phospholipase A2 for AA releasemay be the reason for increased RBC membrane AA.Osterode and Ulberth(2000)1 hErythrocytes from healthyhuman volunteers— Pb inhibits Gordos effect in human erythrocytes; electron spinlabeling studies indicated cell shrinkage and decreased volume.Eriksson and Beving(1993)1 μM Pb nitrate,In vitro6 and 12 mo Erythrocytes from Pb-exposedratsCation-osmotic hemolysis (COH) in 12 mo Pb-exposed rats waslower in the areas of lower ionic strength on erythrocyte membranes.Mojzis and Nistiar(2001)0.1–200:M,Pb nitrate in thereaction buffer1–6 hIn vitro, human erythrocytes— Pb crosses the erythrocyte membrane by the anion exchanger andcan also leave erythrocytes by a vanadate–sensitive pathway,identified with the calcium pump.The high ratio of erythrocyte toplasma Pb seen in vivo appeared tobe due to the presence of a labilePb2+- binding component present inerythrocyte cytoplasm.Simons (1993a)0.1–10 μM Pb ionsfrom 10 mMPb(NO3)2 solution,In vitro24 hErythrocytes from healthyhuman volunteers— Pb activates erythrocyte K+channels, Ca2+sensitive erythrocyteScramblase, triggers Phosphatidyl serine receptors and result in cellshrinkage and decreased life span.Kempe et al. (2005)

# AX5-4Table AX5-2.1 (cont’d). Effect of Lead on Erythrocyte Morphology, Mobility, and Other Miscellaneous ParametersDose and Route ofExposureDuration Species BloodleadEffectAuthors— Pb attenuates prolytic effect onneonatal erythrocytes in iso-orhypotonic low ionic strength media.Serrani et al. (1997)20 μM Pb ion,In vitro2 min–2 h Erythrocytes from humanumbilical cordHemolytic activity of Organo Pbs increases with theirhydrophobicity: triethyl Pb chloride < tri-n-propyl Pb chloride< tributyl tin chloride.Kleszcyńska et al.(1997)20 μM Pb ions,In vitro1 h Human umbilical corderythrocytes— Pb ions increase the resistance tolysis in media of diminishingtonicity. These changes might bemediated by changes in membranestructure.Corchs et al. (2001)Erythrocytes fromPb-exposed workers24–45 yr old whitemalesDuration ofexposure notgiven. RBCswere isolated.Experimentswere performedin ghosts andresealedmembranesHumans1.17–1.54 μM Increased blood Pb inexposed workers was associated with asignificant decrease in the averagemicroviscosity of resealed andunsealed erythrocyte membranes. Alterations in the microviscosityof the lipid regions of the hydrophobic core of the erythrocytemembrane bilayer and in the phospholipid composition of themembrane may be defects that contribute to the clinical andbiochemical alterations/effects.Cook et al. (1987)0.1 mM Pb finalconcentration,In vitro1 hErythrocytes from healthyhumans— Pb particles adhere to the externaland internal surfaces of the humanerythrocyte membrane and disturb the lamellar organization of lipidbilayers.Suwalsky et al. (2003)1–10 μM Pb acetate,In vitro3 hErythrocytes from healthyhumans— Low concentrations of Pb alterthe physicochemical properties ofproteins and lipids in erythrocyte membranes.Slobozhanina et al.(2005)0–1200 nM Pb,In vitro1 hErythrocytes from healthyhumans— Significant increase in the phosphorylation of membrane cytoskeletalproteins in Pb treated human erythrocytes at concentrations above100 nM mediated by enhanced PKC activity.Belloni-Olivi et al.(1996)

# AX5-5Table AX5-2.1 (cont’d). Effect of Lead on Erythrocyte Morphology, Mobility, and Other Miscellaneous ParametersDose and Route ofExposureDuration Species BloodleadEffectAuthors—— a. 24 adult healthy controls(humans)b. 12 patients with Pbpoisoning (plumbism)symptoms (Pb controls)c. Patients with chronic renalfailure (CRF)Divided into:1. Normal urinary blood Pblevels2. High urinary blood PblevelsControls:!17.1 μg/dLPb controls:80.5 μg/dLCRF!1:18.4 μg/dLCRF!2:18.0 μg/dLUrinary Pb CRF 1:!322 μg/72 hCRF 2:1785 μg/72 hIncreased erythrocyte Zn protoporphyrin to free protoporphyrinratio in Pb controls and remained in the normal range in CRFpatients. CRF patients showedminor abnormalities of erythrocyteheme metabolism, such as low ALAD activity.Fontanellas et al.(2002)Occupational,Human exposure— a. 28 male workers in a Pbrefining factoryb. ControlsExposed:!35.97 μg/100 gControls:5.23 μg/100 gSDS polyacrylamide electrophoresis for erythrocyte membraneproteins showed bands at 3 and 4.1, that significantly decreasedwhile bands 2.3, 6, and 7 significantly increased in the Pb workerscompared with controls.Fukumoto et al.(1983)RBC—Red blood cells; Hb—Hemoglobin; NADH—Nicotinamide adenine dinucleotide dehydrogenase; PKC—Protein kinase C; AchE—Acetyl choline esterase

# AX5-6Table AX5-2.2. Lead, Erythrocyte HemeEnzymes, and Other ParametersDose and Route ofExposureDuration Species Blood lead Effect AuthorsDietary,0–100 μg/g dry wt. ofthe diet35 days Adult male Zebra finches0–1.5 μg/mL Significant negative correlation was observed between blood-Pbconcentration and log ALAD activity. RBC ALAD activity ratio isa sensitive indicator of dietary Pbconcentration regardless of themode of exposure.Scheuhammer et al.(1987)Pb acetate, oralgavage, 1.5 mg/kgb.wt, Pb acetate3 or 11 wks Red-tailed Hawks0.195–0.752 μg/dLErythrocyte phorphobilinogen synthetase was depressedsignificantly with in the 1st wk of treatment. Rapid but briefincrease in free protoporphyrin.Hematocrit, erythrocyte count, Hbwere all decreased and blood viscosity increased in exposed group.Redig et al. (1991)20 μg/mL as Pbacetate in drinkingwater5 wksFemale Wistar Albino rats 37.8 μg/dL Pb exposuredecreases hematocrit, hemoglobin, and the number oferythrocytes and enhances blood viscosity.Toplan et al. (2004)17 μM Me/kg Pbacetate, Per OS5 daysFemaleRabbits— Pb causes a significant decreasein blood ALAD activity, increasesfree erythrocyte protoporphyrins, increases aminolevulinic acidand coporphyrin excretion in urine.Zareba andChmelnicka (1992)1.5 mg Pb/kg bodywt, oral dose8 yrsCynomolgus Monkey,in vitro—Kinetic analyses of erythrocyte*- aminolevulinic acid revealeddifferences in PHoptimum and Michaelis constants with Pbexposure. The ALAD enzyme kinetics of Pb exposed monkeysand humans are similar.Dorward andYagminas (1994)Dogs from urban and ruralareas of Greece326, 97–68 μg/L Significant negative correlation existed between blood-Pb levelsand ALAD activity. 807–992 μmol/PBG/LRBC/h is established asthe normal erythrocyte ALAD range for dogs.Polizopoulou et al.(1994)Occupationalexposure11–22 yrs Human erythrocytes fromexposed populations1.39–1.42 μmol/l Liquid chromatographywith inductively coupled plasmaspectrometry had revealed ALAD to be the principle Pb bindingprotein. The percentage of Pbbound to ALAD was influenced bya common polymorphism in the ALAD gene.Bergdahl et al. (1997)0–20 mg Pb liter!129 days Juvenile Rainbow trouterythrocytes—Significant decreases in the erythrocyte ALAD activity after a 29-days exposure to 121 and 201 mg Pb liter!1.Burden et al. (1998)

# AX5-7Table AX5-2.2 (cont’d). Lead, Erythrocyte Heme Enzymes, and Other ParametersDose and Route ofExposureDuration Species BloodleadEffectAuthors8 wksWistar rats$20!$40 μg/dLPb increases blood and liver Pb, erythrocyte porphyrin content,hypoactivity of both hepatocytic and erythrocytic ALAD.Santos et al. (1999)Pb acetate 160 mg/Lin water— Fish from regions close tothe smelters and down stream— Smelter site fish had elevatedPb concentrations, decreased ALADactivity and species differences inthis inhibitory activity wereapparent that could be attributed to Zn levels.Schmitt et al. (2002)1.46 μmol/liter,In vitro48 hHuman whole blooderythrocyte hemolysates,normal and Pb intoxicatedindividuals— The effects of various divalent cations on erythrocyteporphobilinogen are concentration and PH dependent. Zn restoresthe Pb inhibited activity.Farant and Wigfield(1987)Pb 0.34 μM/L–1.17 μM/L,subcutaneousinjection1 hMale albino New Zealandrabbits— Pb causes the most inhibition and Zn activation of rabbit Erythrocyteporphobilinogen activity.Cu2+, Cd2+, and Hg2+are intermediary.Each divalent ion has a characteristic effect on the PH- activityrelationship of PBG-S.Farant and Wigfield(1990)0–60 pM Pb ion,In vitro20 min Human erythrocyte lysates — Human erythrocyte lysate porphobilinogen activity is increased byZn2+with a Km of 1.6 pM and inhibited by Pb with a Ki of 0.07 pM,Pb reduced the affinity for the substrate 5- aminolevulinate, non-competitively.Simons(1995)200–500 ppm Pb indrinking water14 or 30 days Male ddY mice 24–51 μg/100 mL Pb inhibitserythrocyte and bone marrow P5’N activity. ErythrocyteALAD activity was inhibited by90%. Elevation of Urinaryexcretion of ALA with no change in erythrocyte protoporphyrin andurinary co porphyrin as against in the Pb exposed humans indicatesthat protoporphyrin metabolism might be more resistant to Pb inmice than humans.Tomokuni et al.(1989)0.1–100 μM Pb ion,In vitro5 minHuman erythrocyte ghosts— Under normal incubation conditions Pb inhibits, Ca2+-Mg2+ATPasewith an IC50 of 6.0μM. Pb inhibits Ca2+- Mg2+ATPase related tosulphahydryl groups above 1.0 μMPb and by direct action of Pbupon Calmodulin below 1.0 μM.Mas-Oliva (1989)20–5 μg/kg body wt1 mg/ kg body wtPregnancythrough lactationErythrocytes from Sprague-Dawley rats— Na2+- K+- ATPase and Ca2+- Mg+- ATPase of erythrocyte membranesfrom Pb-depleted animals did notchange in P0 generation ascompared to 1 mg/kg b.wt Pb animals, where as in F1 generation Pbdepleted rats showed reduced activity.Eder et al. (1990)

# AX5-8Table AX5-2.2 (cont’d). Lead, Erythrocyte Heme Enzymes, and Other ParametersDose and Route ofExposureDuration Species BloodleadEffectAuthors20 mg Pb acetate/kgb.wt, i.p,In vivo14 days Male Albino ratserythrocytes— Pb significantly decreases erythrocyte membrane acetyl choline esterase,NADH dehydrogenase, membrane sialicacid, hexose, and hexosamine.Jehan and Motlag(1995)Pb ions inhibit aerobic glycolysis and diminish ATP level in humanerythrocytes in vitro. Magnesiumpartly abolishes these effects bystimulating Magnesium dependent enzymes. Effect is seen both bydirect addition of Pb acetate to erythrocyte ghosts as well as in the ghostsobtained after preincubation of erythrocytes with Pb acetate. Ca2+, Mg2+ATPase is less sensitive and Mg ATPaseis practically insensitive to Pbunder these conditions.Grabowska andGuminska (1996)10–200 μg/dL Pb ions(Pb acetate),In vitro20 hHuman umbilical corderythrocytes— Pb significantly decreased the concentration of ATP, ADP, AMP,adenosine, GTP, GDP, GMP, Guanosine, IMP, inosine, hypoxanthine,NAD and NADP concentrations.Baranowska-Bosiackaand Hlynczak (2003)Pb acetate throughwater or i.p. 1 or2 mg/Kg b.wt.Every 4th dayfor 1 moWistar rats1.51–35.31 μg/dLThe concentrations of adenosine tri phosphate (ATP), Guanosinetriphosphate (GTP), Nicotinamide adenine dinucleotide NAD+,nicotinamide adenine dinucleotide phosphate NADP+adenylate andGuanylate (AEC and GEC) were significantly reduced in erythrocytes ofexposed animals. Results indicate Pb ions disrupt erythrocyte energypathway.Baranowska-Bosiackaand Hlynczak (2004)ALAD — Aminolevulinic acid; Cu2+—Copper; Cd2+—Cadmium; Hg2+—Mercury; PBG-S Porphobilinogen synthetase; Zn—Zinc; ATP—Adenosine triphosphate; ADP—Adenosine diphosphate;AMP—Adenosine monophosphate; GTP—Guanosine tri phosphate; GDP—Guanosine diphosphate; GMP—Guanosine monophosphate; IMP—Inosine monophosphate; NAD—Nicotinamideadenine dinucleotide; NADP—Nicotinamide adenine dinucleotide phosphate.

# AX5-9Table AX5-2.3. Lead Binding and Transport in Human ErythrocytesDose and Route ofExposureDuration Species BloodleadEffectAuthors0–60 pM Pb ion,In vitro20 min Human erythrocyte lysates — Human erythrocyte lysate porphobilinogen activity is increased by Zn2+with a Km of 1.6 pM and inhibited by Pb with a Ki of 0.07 pM, Pbreduced the affinity for the substrate 5- aminolevulinate, non-competitively.Simons (1995)Zn—Zinc

# AX5-10Table AX5-2.4. Lead Effects on Hematological ParametersDose and Route ofExposureDuration Species Blood lead Effect Authors4-6 mg/Kg b.wt, i.p.,daily15 and 30 days Intact and splenctamized rats—Pb increases urinary*-amino levulinic acid (ALA) excretion,depletion in RBC hemoglobin content, and more number ofreticulocytes in peripheral blood,and results in accumulation ofimmature erythrocytes both in intact and splenctomized rats.Gautam andChowdhury (1987)0.82 mg Pb/kgb.wt./d, oral gavage3 or 11 wks Red-tailed hawks erythrocytes 0.195–0.375 mg/mL Activity of porphobilinogen synthase/ALAD was depressedsignificantly in Pb exposed rats and did not return to normalvalues until 5 wks after the termination of the treatment. A rapidand relatively brief increase in erythrocyte free proto porphyrinand a slower, prolonged increase in Zn complex.Redig et al. (1991)17 μM Me/Kg b.wtPb acetate or 3.5 mgof Pb/kg body wt, i.p5 daysFemale Rabbits17.5 μg/dLPb causesa significant inhibition of ALAD in the blood ,increases free erythrocyte protoporphyrin, and urinary excretionof Aminolevulinic acid and coporphyrin.Zareba andChmielnicka (1992)17 μM Me/Kg b.wtPb acetate or 3.5 mgof Pb/ kg body wt, i.p.or per OS 17.5 mg/kgb.wt single injection5 days i.p. Female Rabbits— Pb induced ALASactivity in liver and kidney, both after i.p andp.o. administration; i.p. administration of Pb also induced kidneyheme oxygen levels.Chmielnicka et al.(1994)Cu deficient 1 mgCu/KgMarginal deficient2 mg/kgControl 5 mg Cu/KgHigh Zn 60 mg/kg.4 wksRat— Moderately high Zn inthe diet reduces plasma copper but notplasma ceruloplasmin.Does not affect the recovery of plasma Cu or activity after oralcopper sulphate in Cu deficient diets.Does not influence RBC Super oxide dismutase activity.Panemangalore andBebe (1996)0.02–40 ppm Pb,dietary90 days Male and female Swiss mice0.7–13.0 μg/dL Increased RBC number and increased hemoglobin and decreasedhematocrit up on Pb exposure.Iavicoli et al. (2003)20 μg/mL, Pb acetatein drinking water5 wksFemale Wistar Albino rats 37.8 μg/dLErythrocyte count, hematocrit and hemoglobin were all decreasedand blood viscosity increased in Pb exposed workers.Toplan et al. (2004)

# AX5-11Table AX5-2.4 (cont’d). Lead Effects on Hematological ParametersDose and Route ofExposureDuration Species BloodleadEffectAuthorsErythrocytes fromhumans ofoccupational Pbexposure and controlsIn vivo and in vitro— Male Pb workers and13 normal volunteersRange 20.6–71.3 μg/dLNicotinamide adenine dinucleotide synthetase activity in the Pb workersranged from 0.08 to 1.1 μmol/h per g of hemoglobin. 50% of enzymeinhibition was observed at 40 μg/dL.Aminolevulinic acid dehydrataseactivity decreased rapidly and reached a plateau at Pb-B levels 40-60μg/dL. 50% of enzyme activity inhibition was observed at 20 μg/dL.Morita et al. (1997)In vivo; exposureIn vitro assays onerythrocytes fromexposed populations— 1. Workers exposed tomanganese (Mn) and2. Workers exposed to Pbwithout clinicalmanifestations ofintoxication— Erythrocyte concentrations of adenyl nucleotides (ADP and ATP) wereelevated in both groups of workers and that of AMP in Pb-exposedworkers. The ratio of ATP/ADP significantly increased in Pb-exposedworkers.Nikolova andKavaldzhieva et al.(1991)ALA—Aminolevulinic acid; ALAS—Aminolevulinic acid synthetase; ALAD—Aminolevulinic acid dehydratase, RBC—Red blood cells.

# AX5-12Table AX5-2.5. Lead Interactions withCalcium Potassium in ErythrocytesDose and Route ofexposureDuration Species BloodleadEffectAuthors0–325 μM, Pb nitrate,In vitro0–60 min In vitro — Pb modifies the threshold sensitivity of individual K+channels to Ca2+with a biphasic time course. The increase of Pb concentration increasedthe extent of the initial inhibitionand decreased the duration. Theinhibitory effect was not observedwhen addition of Calcium precededthe addition of Pb. Pb decreased the rate of uptake of86Rb.Alvarez et al. (1986)0 μM–5 mM Pb,In vitro0–100 min Human erythrocytehemolysates— Pb and Ca transport was carried out by a passive transport system withtwo kinetic components (Michaelis- Menten and Hill) Pb and Ca werecapable of inhibiting the transport of the other metals in a non-competitive way.Calderon-Salinaset al. (1999b)1–4 μM Pb acetate,In vitro0–30 min Rabbit reticulocytes— Pb at low concentrations inhibits the uptake ofFe (II) into all three(heme, cytosolic and stromal) fractions. The saturable components wereinhibited at lower concentrationsof Pb than the non- saturablecomponents.Qian and Morganet al. (1990)1–50 μM Pb ion,In vitro20 minMarine fish erythrocytes— Pb activates Ca2+activated potassium channels. Treatment oferythrocytes with 1-2 μM Pb led toa minor intra cellular K loss and atPb concentrations of 20-50 μM 70% of potassium was lost.Silkin et al. (2001)Pb depleted ratsPb concentration<20 μg/kgDiet, oralPb controls200,800 μg/kg Pb2+inthe form of supra purePb acetate. Diet, oralGestationthrough to15 days oflactationSprague-Dawley rats— The concentration of CA2+ions in erythrocytes of Pb-depleted rats waselevated in F1generation, without changes in P0generation. Theelevation observed in depleted rats could be because of a reduction inCA2+-Mg2+ATPase.Loipführer et al.(1993)Intact or erythrocyteghosts0–100 μM Pb ion orPb nitrate in thereaction mix,In vitro10 minHealthy human erythrocytes— Modulation of CA2+-activatable K+permeability was compared withmodulation of a membrane-bound oxidoreductase activity in humanerythrocytes. Pb, anitrion, and menadione had parallel effects on thechannel protein and the enzyme. The results demonstrate that the K+channel and the enzyme are distinct membrane proteins and the enzymeactivity may influence channel gating.Fehlau et al. (1989)Pb—Lead; K+—Potassium; Na2+- K+ATPase—sodium potassium ATPase; Ca2+- Mg2+ATPase—Calcium, Magnesium ATPase.

# AX5-13Table AX5-2.6. Lead, Heme, and Cytochrome P–450Dose and Route ofexposureDuration Species BloodleadEffectAuthors0–75 mg of Pb2+/Kg b.wt. i.p., Singleinjection0–30 hC57 BL/6 male mice—Pb causes an increase in*-amino levulinic acid levels in plasma and adecrease in the heme saturation of hepatic tryptophan -2,3 dioxygenase.P-450- dependent activities,EROD and O-dealkylation ofalkoxyresorufins decreased progressively. Pb exposure decreasedmRNA levels of the P450 CYp3a11. The decrease in P450 transcriptionwas a mechanism dependent on hemeby inhibition of heme synthesisand also by a mechanism independent of heme in which Pb decreases P-450 transcription.Jover et al. (1996)EROD—Ethoxy resorufin-O-dealkylase.CYp3a11—Cytochrome P-450 3a11.

# AX5-14Table AX5-2.7. Lead, Erythrocyte LipidPeroxidation, and Antioxidant DefenseDose and Route ofexposureDuration Species BloodleadEffectAuthors7.5 mg of Pb acetateor 4.09 mg of PbKg-1b.wt, oral28 days,multipleanalyses at day7, 14, 21, and 28Erythrocytes from male Calves 0.1–1.6 ppm Pb exposuresignificantly reduced erythrocyte super oxide dismutaseactivity until day 21 followed by a marginal increase by day 28. Total,protein-bound and non protein- bound–SH content of erythrocytesdeclined.Patra and Swarupet al. (2000)5.46 mg Pb as Pbacetate, oral14 days,multipleanalyses at day0, 7, and 14Erythrocytes from female goats 0.09–1.12 ppm Pb exposurecaused a significant increase oferythrocytic GPx, SOD andCAT activities, total thiol groupsand total antioxidant status.Mousa et al. (2002)10 mg/kg b.wt Pbacetate, intramuscular, dailyPre treatment withmelatonin7 daysRat— Pb significantly decreased hemesynthesis, decreased Hb, decreased liver*- ALAS and erythrocyte ALAD. Markedly elevates hepatic lipidperoxidation, reduced anti oxidant enzymes such as total sulphahydrylgroups and Glutathione. Pre Treatment with melatonin reduced theinhibitory effect of Pb on both enzymatic and non enzymaticantioxidants and reduced the iron deficiency caused by Pb.El- Missiry (2000)A. ALA 40 mg/kgb.wt every other dayand/orB. Melatonin10 mg/kgEvery other day3 times daily for2 wksMale Sprague- Dawley rats— Melatonin effectively protects nuclear DNA and lipids in rat lung andspleen against the oxidative damagecaused by the carcinogen ALA.Karbownik et al.(2000)Pb acetate 0.2%, indrinking water,followed byindividual orcombined treatment oflipoic acid (25 mg/Kgb.wt and DMSA20 mg/kg b.wt, i.p.)5 wksMale Albino rats97.5 μg/dL Pb exposureresults in decreased blood hemoglobin, hematocrit,enhanced erythrocyte membrane lipid peroxidation, decline in theactivities of erythrocyte membrane Na+-K+ATPase, Ca2+ATPase, andMg2+ATPase. Treatment with lipoic acid and/or DMSA reduced the Pbinduced adverse changes in the biochemical parameters.Sivaprasad et al.(2003)*-Aminolevulinicacid, 1-5 mM, In vitro10 days CHO cells—*- Aminolevulinic acid treatment induces oxidative stress in Chinesehamster ovary cells by inducing Glutathione, Glutathione disulphide,Malandialdehyde equivalents, and Catalase. N-acetyl cysteineadministration reverses the decrease in cell survival and colonyformation induced by*- ALA.Neal et al. (1997)SOD—Super oxide dismutase; CAT—Catalase; ALAS—Aminolevulinic acid synthatase, ALAD—Aminolevulinic acid dehydratase; ALA—Aminolevulinic acid; GPx—Glutathione peroxidase

# AX5-15 

# ANNEX TABLES AX5-3

# AX5-16Table AX5-3.1. Summary of Key Studies on Neurochemical AlterationsSubject ExposureProtocolPeak Blood Pb or[Pb] usedObserved EffectsReferenceRatPND 16–18Hippocampal cultures0.1 and 1.0 μMPb Cl2Pb blockage of IPSCs were partially reversible while EPSCswere not. Braga et al. (2004)RatPND 501500 ppm Pb(Ac)2chow 10 days before breeding andmaintained to sacrifice31.9 μg/dL Decreases the NR1 subunit splice variant mRNA in hippocampus. Guilarte andMcGlothan (2003)RatPND 7, 14, 21,28, and 501500 ppm Pb(Ac)2chow 10 days before breeding andmaintained to sacrifice— Alters NMDAR subtypes and reduces CREB phosphorylation. Toscano et al. (2002)RatPND 21750 ppm Pb(Ac)2chow from GD 0 to PND 2146.5 μg/dL Increased expression of nicotinic receptors. Jett et al. (2002)Cultured PC12 cells 0.03–10 μMPb(NO3)2Pb acts as a high affinity substitute for calcium in catecholaminerelease.Westerink andVijverberg (2002)Adult rat Water—0.1–1.0% Pb(Ac)2from GD 15 to adult61.8 μg/100 mL Hippocampal GLU and GABA release exhibits biphasic effects fromchronic Pb.Lasley and Gilbert(2002)Adult rat Water—0.1–1.0% Pb(Ac)2from GD 15 to adult117.6 μg/100 mL NMDA receptor function is upregulated. Lasley et al. (2001)Cultured PC12 cells 0.53 μM Pb(Ac)2PKC is involved in TH upregulation but not downregulationof ChAT. Tian et al. (2000)Embryonic rat Hippocampal neurons100 fM–100 nM Decreases [Ca2+]i and increases Ca2+efflux by a calmodulin-dependentmechanism.Ferguson et al.(2000)Rat750 or 1500 ppm Pb(Ac)2chow from 10 days pre-mating toPND 14, 21, and 2861.1 μg/dL Dose-response effect between level of Pb and expression ofNR1 gene. Guilarte et al. (2000)Cultured PC 12 cells5–20 μM Pb(Ac)2Induces expression of immediate early genes but requires PKC. Kim et al. (2000)

# AX5-17Table AX5-3.1 (cont’d). Summary of KeyStudies on Neurochemical AlterationsSubject ExposureProtocolPeak Blood Pb or[Pb] usedObserved EffectsReferenceRatPND 50750 or 1500 ppm Pb(Ac)2chow from 10 days pre-mating toPND 5031.9 μg/dL Reductions in NMDAR receptors result in deficits in LTP and spatiallearning.Nihei et al. (2000)Calcineurin in mixture10–2000 pMPb(NO3)2Has a stimulatory (low) and inhibitory (high)effect on calcineurin. Kern and Audesirk(2000)Adult rat Cerebrocortical membranes 0.01–4 μMfree Pb(Ac)2Pb binds to the NMDA receptor channel in a site different from zinc. Lasley and Gilbert(1999)Adult ratPND 20.2% Pb(Ac)2in water and chow52.9 μg/100 mL GLU and GABA release areinhibited independent of Pb exposureperiod.Lasley et al. (1999)RatCultured hippocampal neurons 0.01–10 μM Pb Cl2Inhibits glutamatergic and GABAergic transmission via calciumchannel.Braga et al. (1999a)RatPND 17Cultured hippocampal neurons 0.1–10 μM Pb Cl2Increases tetrodotoxin-insensitive spontaneous release of GLU andGABA.Braga et al. (1999b)RatPND 7, 14, 21,28750 ppm Pb(Ac)2chow from 14 days pre-mating toexperimental use59.87 μg/dL NMDAR-2A subunit protein expression is reduced in thehippocampus.Nihei and Guilarte(1999)RatPND 7, 14, 21,28750 ppm Pb(Ac)2chow from 14 days pre-mating toexperimental use59.87 μg/dL Alters the levels of NMDA receptor subunits mRNA in hippocampus. Guilarte andMcGlothan (1998)RatPND 22-adultWater—0.2% Pb(Ac)2from GD 16 to PND 21—Induces loss of septohippocampal cholinergic projection neurons inneonates lasting into young adulthood.Bourjeily andSuszkiw (1997)RatPND 28 56,112Water—1000 ppm Pb(Ac)2from GD 4-use39.6 μg/dL Significant increase in [3H]MK-801 binding after chronicexposure. Ma et al. (1997)

# AX5-18Table AX5-3.1 (cont’d). Summary of KeyStudies on Neurochemical AlterationsSubject ExposureProtocolPeak Blood Pb or[Pb] usedObserved EffectsReferenceRatPND 21–adult50 or 150 ppm Pb(Ac)2water for 2 wks–8 mo28.0 μg/dL Differential effects in [3H]MK-801 binding with dopamine and D1agonists.Cory-Slechta et al.(1997a)Adult rat Water—0.2% Pb(Ac)2from PND 0–adult37.2 μg/100 mL Presynaptic glutamatergic function in dentate gyrus is diminished. Lasley and Gilbert(1996)Rat4 moWater—0.2% Pb(Ac)2from GD 16 to PND 2822.0 μg/dL Developmental Pb results inlong-lasting hippocampal cholinergicdeficit.Bielarczyk et al.(1996)RatPND 111Water at 50 ppm Pb(Ac)2for 90 days; start at PND 2118 μg/dLDecreases in vivo release of dopamine in the nucleus accumbens. Kala and Jadhav(1995)Cultured bovine chromaffin cells Variable kind andconcentrationExerts dual stimulatory andinhibitory effects on adrenal PKC. Tomsig and Suszkiw(1995)Rat Homogenizedcortex RangingPb(Ac)2Pb activates PKC in the range of 10−11to 10−8M.Long et al. (1994)Cultured bovine chromaffin cells Variable kind andconcentrationPb and calcium activate the exocytotic release of norepinephrine. Tomsig and Suszkiw(1993)Review paper discussing Pb-calcium interactions in Pb toxicity. Simons (1993b)Review paper exploring Pb asa calcium substitute.Goldstein (1993)RatPND 14 or 56Neuronal membranesChow containing750 ppm Pb(Ac)2Inhibitory effect on [3H]MK-801 binding and loss of binding sites inneonates.Guilarte and Miceli(1992)Rat Corticalsynaptosomes 1–50 nM free Pbor 1 μM Pb(NO3)2Triggers acetylcholine release more effectively than calcium.Shao and Suszkiw(1991)

# AX5-19Table AX5-3.1 (cont’d). Summary of KeyStudies on Neurochemical AlterationsSubject ExposureProtocolPeak Blood Pbor [Pb] usedObserved EffectsReferenceRat Hippocampalneurons 2.5–50 μM Pb Cl2Pb has a blocking effect on the NMDA subtype of glutamate receptors. Alkondon et al.(1990)RatBrain protein kinase C 10−10M Pb salts Stimulates brain protein kinase C and diacylglycerol-activatedcalcium. Markovac andGoldstein (1988b)AbbreviationsGD—gestational day

# AX5-20Table AX5-3.2. Summary of Key Studieson Neurophysiological AssessmentsSubject ExposureProtocolPeak Blood Pbor [Pb] usedObserved EffectsReferenceRatPND 22250 ppm Pb(Ac)23–6 wks (electro) or 7-13 wks(immuno)30.8 μg/dL Reduces midbrain dopamine impulse flow and decreases dopamine D1receptor sensitivity in nucleus accumbens.Tavakoli-Nezhadand Pitts (2005)RatPND 42–64100, 250, or 500 ppmPb(Ac)2in chow for 3-6 wks54.0 μg/dL Decrease in number of spontaneously active midbrain dopamine neurons. Tavakoli-Nezhadet al. (2001)Review paper examining glutamatergic components contributing toimpairments in synaptic plasticity.Lasley and Gilbert(2000)RatPND 130–2100.2% Pb(Ac)2in water75.4 μg/dL Deficits in synaptic plasticity in the dentate gyrus from early exposure. Gilbert et al.(1999a)Adult rat Water—0.1-1.0% Pb(Ac)2from GD 16 to adult117.6 μg/dL Biphasic dose-dependent inhibition of hippocampal LTP. Gilbert et al.(1999b)Adult rat 0.2% Pb(Ac)2in water30.1 μg/dL Chronic Pb exposure significantly decreasesrange of synaptic plasticity. Zhao et al. (1999)Adult rat 0.2% Pb(Ac)2in water PND 0-2130.1 μg/dL Impairments in LTP and paired-pulse facilitation in the hippocampal DG. Ruan et al. (1998)RatPND 90–130750 ppm Pb(Ac)2chow from 50 days pre-mating toexperimental use16.04 μg/100 mL NMDA-dependent forms of synaptic plasticity are more vulnerable thanNMDA-independent potentiationor paired pulse-facilitation.Gutowski et al.(1998)Rat 7–18 mo Water—0.2% Pb(Ac)2from GD 16 to experimental use— Impairs ability to maintain LTP over time in the dentate gyrus. Gilbert and Mack(1998)RatPND 13–140750 ppm Pb(Ac)2chow from 50 days pre-mating toexperimental use28.5 μg/dL Paired-pulse stimulation of CA3 regionshows inhibitory mechanisms. Gutowski et al.(1997)Adult rat Water—0.2% Pb(Ac)2from PND 0–adult— Chronic Pb increases the threshold for LTP in dentate gyrus in vivo. Gilbert et al.(1996)RatPND 4–30Hippocampal neurons 1–100 μM Pb Cl2Identified the nicotinic acetylcholine receptor as a target for Pb.Ishihara et al.(1995)Rat750 ppm Pb(Ac)2chow from 50 days pre-mating toexperimental use16.2 μg/100 mL LTP and learning are impaired if exposed to Pb in the immature brain. Altmann et al.(1993)AbbreviationsGD—gestational day

# AX5-21Table AX5-3.3. Summary of Key Studieson Changes in Sensory FunctionSubject ExposureProtocolPeak Blood Pbor [Pb] usedObserved EffectsReferenceMicePND 7–900.15 % Pb(Ac)2in dams water from PND 0–2126 μg/dL Produces a rod photoreceptor-selective apoptosis inhibited by Bcl-xloverexpression.He et al. (2003)Rat retinas0.01–10 μMPb Cl2Pb and calcium produce rod photoreceptor cellapoptosis via mitochondria. He et al. (2000)RatPND 21 or 900.02% and 0.2% Pb(Ac)2in dams water PND 0–21 and3wks as adult59.0 μg/dL Functional alterations and apoptoticcell death in the retina.Fox et al. (1997)Monkey13 yrs2 mg/kg/d Pb(Ac)2in capsule for 13 y168.0 μg/dL Mild increase in detection of pure tones outside of threshold. Rice (1997)Monkey 350 or 600 mg Pb(Ac)2for 9.75 yrs55 μg/dL Consistent prolongations of latencies on the brain stem auditory evokedpotential.Lilienthal andWinneke (1996)Bovine retinas50 pM–100 nMPb(Ac)2Direct inhibition of purified rod cGMP PDE, magnesium can reverse effect. Srivastava et al.(1995)Ratretinas 10−9to 10−4M Alters several physiological and biochemical properties of rodphotoreceptors. Fox et al. (1994)Review paper examining effects upon auditory and visual function.Otto and Fox(1993)Adult rat 0.02% and 0.2% Pb(Ac)2in dams water PND 0–2159.4 μg/dL Inhibits adult ratretinal, but not kidney, Na+, K+-ATPase.Fox et al. (1991b)Monkey 6 yr Glycerine capsule with 25 or2000 μg/kg/d Pb(Ac)2220 μg/dL Morphological damage in the visualcortical area V1 and V2. Reuhl et al.(1989)RatPND 900.2% Pb(Ac)2in dams water PND 0–210.59 ppm Long-term selective deficits in rod photoreceptor function and biochemistry. Fox and Farber(1988)

# AX5-22Table AX5-3.4. Summary of Key Studies on Neurobehavioral ToxicitySubjectExposureProtocolPeak Blood Pbor [Pb] Used Observed Effects ReferenceRat, female,22wks75 or 300 ppm Pb(Ac)239 μg/dL Significantly impaired on the alteration task with variable intertrial delays. Alber and Strupp(1996)RatWistar750 ppm Pb(Ac)215 μg/dL Pb-induced deficits in AAL in ratsexposed to Pb either during pre-weaningor pre- and postweaning: postweaning-only exposure caused reduced deficitsin AAL.Altmann et al.(1993)Rat, LE,postweaning50 ppm Pb(Ac)215.1 μg/dL Quinpirole at 0.05 mg/kg reversed the effects of Pb on FI performance;eticlopride had no effect on response rates in Pb-treated animals.Areola andJadhav (2001)Rat, LE, malePostweaning50 or 150 ppm Pb for 3 mo 10.8 and28.5 μg/dLFR: 150-ppm rats—significantly higher response rates and component resetsthan the low dose group and controls. Waiting behavior: wait time was lowerin both treated groups. 150-ppm rats—increased number of reinforcers and ahigher response to reinforcement ratio than low dose and controls.Brockel andCory-Slechta(1998)Rat, LE, malePostweaning50 or 150 ppm Pb for 3 mo 9.7 and26.2 μg/dL after3 and 7 moD2agonist quinpirole reversed the Pb-induced effects on FR-response rate,FRresets, wait reinforcers, and wait time.Brockel andCory-Slechta(1999a)Rat, LE, malePostweaning50 or 150 ppm Pb for 3 mo 16.0 and28.0 μg/dLNo Pb-induced effects on sustained attention.Brockel andCory-Slechta(1999b)Rat, SD, adult 500 ppm Pb(Ac)220.9 μg/dL Chronic Pb exposure attenuated the reinforcing effect of brain stimulation. Burkey andNation (1994)Rat, SD 0.2% Pb(Ac)2during gestationand lactation,postweaningonly, or continuouslyPND 56: 3.8,25.3, and29.9 μg/dLNo Pb-associated effects in learning performance with just maternal orpostweaning exposure. Continually exposed rats tended to avoid lessfrequently and in two-way active avoidance training, did not respondmore frequently.(Chen et al.(1997a)

# AX5-23Table AX5-3.4 (cont’d). Summary of Key Studies on Neurobehavioral ToxicitySubjectExposureProtocolPeak Blood Pbor [Pb] UsedObserved EffectsReferenceRat, SD 0.2% Pb(Ac)2during gestationand lactation,postweaningonly, or continuouslyPND 56: 3.8,25.3, and29.9 μg/dLAll Pb-treated groups: impaired learning acquisition but unimpaired memoryretention; possible alterations in AMPA receptor binding.Chen et al. (2001)Rat, LE, male 50or 250 ppm Pb(Ac)2chronically from PND 2125.1 and73.5 μg/dLPb-induced decrements in accuracy onthe learning component, but not on theperformance component compared; Pbexposure impaired learning byincreasing preseverative responding on a single lever, even though suchrepetitive responding was not directly reinforced.Cohn et al. (1993)Rat, LE, male 50or 250 ppm Pb(Ac)2chronically from PND 2125.1 and73.5 μg/dLPb exposure: attenuated the decline inlearning accuracy and the increases inpreseverative responding produced by MK-801; dose-effect curves relatingMK-801 dose to changes in rates of responding were shifted to the right.Cohn and Cory-Slechta (1993)Rat, LE, male 50or 250 ppm Pb(Ac)2in water PND 21-use73.5 μg/dL Pb-induced potentiation of the accuracy-impairing effects of NMDA by furtherincreasing the frequencies of errors and likewise potentiated the drug’s rate-suppressing effect; learning impairments are not caused by changes indopaminergic function.Cohn and Cory-Slechta (1994a,b)Rat, LE, male 50 or 500 ppmfrom weaning 30.3 and 58–94 μg/dL50-ppm group: no effects. 500-ppm group:response rates initially decreased,then reached control levels, primarily due to longer interresponse times.FI response rates are more sensitive to perturbation by Pb than FR.Cory-Slechta(1986)Rat, LE, male,PND 2150 ppm PbS8–11 mo~20 μg/dL Decreased FI response rates (i.e., longer IRTs and lower running rates)compared to controls.Cory-Slechta(1990a)6–8.5 mo 50 or 500 ppm3–5 moDemonstrated no consistent changes inFI performance, suggesting that once abehavior has been acquired, it may beresistant to the adverse effects ofsubsequent Pb exposure.Rat, LE, male,PND 2150 or 250 ppm Pb(Ac)273.2 μg/dL Increased sensitivity tothe stimulus properties of dopamine D1and D2agonists. Cory-Slechta andWidowski (1991)Rat, F344,PND 218 mo,16 mo2 or 10 mL/kg/d Pb(Ac)2for9.5 mo13–18 μg/dLsteady stateYoung and old rats: increased VI and FIresponse rates; adult rats: decreasedresponse rates on both schedules. Effectson FI seen with 2-mg dose and VIwith only the 10-mg dose.Cory-Slechtaand Pokora(1991)

# AX5-24Table AX5-3.4 (cont’d). Summary of Key Studies on Neurobehavioral ToxicitySubjectExposureProtocolPeak Blood Pbor [Pb] UsedObserved Effects ReferenceRat, F344,male2 or 10 mg/kg Pb(Ac)22 mg: 23; 10 mg:42 (adult),~48 (old),~58 μg/dL(young)Aging caused impaired accuracy: In both young and old rats: Pb-inducedincrease in accuracy, at the longest delay periods (12 s) in young rats, and at theshort delay periods in old rats. Adults: not affected by Pb exposure.Cory-Slechtaet al. (1991)Rat, LE, male 100 or 350 ppm Pb(Ac)2in dam’s water PND 0–2134 μg/dL Induced functional D2-D3supersensitivity to the stimulus properties of agonist. Cory-Slechtaet al. (1992)Rat, LE, male 50or 150 ppm Pb(Ac)2from weaningCAltered cholinergic sensitivity due to Pband several agonists.Cory-Slechta andPokora (1995)Rat, LE, male 50or 150 ppm Pb(Ac)235.7 μg/dL Postweaning Pb exposure resultedin an MK-801 subsensitivity.Cory-Slechta(1995)Rat, LE, male 50or 150 ppm Pb(Ac)2in water PND 21-use30.6 μg/dL (1) Enhances the stimulusproperties of NMDA via a possibledopaminergic path.(2) Low level Pb exposure is associated with D1subsensitivity.Cory-Slechtaet al. (1996a,c)Rat, LE, male 50or 150 ppm Pb(Ac)2from weaning15–2530–50 μg/dLPb exposures attenuated the decrements in rates produced by the two D1agonists SKF38393 and SKF82958, and at150 ppm, Pb exposure altered therate change associated with the low dose (0.033mg/kg) of quinpirole.Cory-Slechtaet al. (1996b)Rat, LE, male 100 or 350 ppm Pb(Ac)2from weaning35.0 μg/dL Post-washout decrease in sensitivity to MK-801. Cory-Slechta(1997)Rat, LE, male 50or 500 ppm Pb(Ac)2from weaning49.1 μg/dL Increases FI schedule-controlled behavior in nucleus accumbens. Cory-Slechtaet al. (1998)Rat, LE, male 50or 500 ppm Pb(Ac)2from weaning49.1 μg/dL Both DA and EEDQ, microinjected into the dorsomedial striatum, causedincreases or decreases in FI responserates, which depended on baseline FIoverall rates.Cory-Slechtaet al. (2002)

# AX5-25Table AX5-3.4 (cont’d). Summary of Key Studies on Neurobehavioral ToxicitySubjectExposureProtocolPeak Blood Pbor [Pb] UsedObserved EffectsReferenceHamster,Golden100 ppm Pb(Ac)2GD8–PND 42PND 42:10–15 μg/dPND 19–20: Pb-exposed hamsters smaller,exhibited less play fighting.PND 45: Pb-induced increase in aggression.Delville (1999)Rat, Wistar,female8, 16, or 24 mg/mL Pb(Ac)2during pregnancy, pregnancyand lactation, orlactation.5.7–36.6 μg/dL PND 7: dose-dependent decrease in ultrasonic vocalization. PND 14:increased vocalization, andhigher activity levels.De Marco et al.(2005)BK:W mice,male andfemale0.13% Pb(Ac)2chronicallystarted before breedingBrain and femur:18 wks:27.6 and 99834 wk: 445 and5, 364 (M)34 wk: 787 and4, 026 (F)Young Pb-exposed female mice habituated more slowly. Young Pb-exposedmales habituated more rapidly.Adults: Pb-induced enhancement ofsocial and sexual investigation.Donald et al.(1986)BK:W mice,male andfemale0.25% Pb(Ac)2chronicallystarted beforebreeding3–4 wks: Pb-induced increase in exploratory behavior and social investigationin exploratory behavior. 15–16 wks: Pb-induced decrease in nonsocial activityin females, increase in males. 17–18wks: Pb-induced shorter latencies toaggression in males.Donald et al.(1987)Monkey,rhesus,4 yrs10 mg/kg/d pulses (2) andchronic 0.7 for first yr of life5 wks: 55 μg/dLfirst yr: ~36 yr 4:<5Pb-induced longer latency to enter the open area, increased durations ofenvironmental exploration and activity, and resulted in a failure to habituate.Ferguson andBowman(1990)Rat, SD 350 ppm Pb(Ac)2from birthuntil weaning46 μg/dL No Pb-related effects in play, burrowing, dominance, residential running wheel,residential figure-8 maze, complex maze, acoustic startle, emergence, prepulseinhibition.Ferguson et al.(1998)Rat LE,PND 53300 or 600 ppm Pb(Ac)2duringgestation and lactation orlactation only16, 12, and18 μg/dLTwo-choice olfactory serial reversal task: Pb-treated groups took more trials toreach the point where repeated responding to the previously correct cue ended.Garavan et al.(2000)

# AX5-26Table AX5-3.4 (cont’d). Summary of Key Studies on Neurobehavioral ToxicitySubjectExposureProtocolPeak Blood Pbor [Pb] UsedObserved EffectsReferenceMonkey,cynomolgus,9–10 yrs of age50 or 100 μg/kg/dPb(Ac)215.4 and25.4 μg/dL; 10.9and 13.1 μg/dL,steady statePb-induced impairment in the presence, butnot the absence, of irrelevant cues;in the lower-dose group monkeys, impairment ended when the irrelevantstimuli became familiar.Gilbert and Rice(1987)Rat, male,adult500 ppm Pb(Ac)2in chow for105 days28 μg/dL Chronic Pb exposure attenuates cocaine-induced behavioral activation. Grover et al.(1993)Rat, LE 1500 ppm Pb(Ac)2gestationand lactation3.9 μg/dL atPND 50Pb + enriched environment: enhanced performance in water maze; increasedgene expression in the hipppocampusof NMDAR subunit 1 and BDNF.Guilarte et al.(2003)Rat, Wistar,male100 mg/kg/body weight byinjectionNot reported Pb-induced deficits in memory component of the radial arm maze test and inretention of passive avoidance learning.Haider et al.(2005)Rat, LE,female75 or 300 ppm Pb(Ac)2inwater GD0 experimental use51 μg/dL Impairment of reversal learning asan associative deficit.Hilson and Strupp(1997)Rat, LE, maleand female500 ppm Pb choride duringlactation42 μg/dL PND 11: no Pb-induced sex differences, effectson pup activity, anddifferences in pup retrieval by dams.PND 26: Pb treatment influenced all social behavior tested (i.e., investigationduration and frequency, crossover frequency, pinning) but did not changeactivity levels.PND 36: Pb-treated pups demonstratedincreased crossover frequencies but nochange in activity levels compared to controls.Holloway andThor (1987)Rat, LE 250 ppm Pb(Ac)2chronicallyfrom gestationHippocampalPb levelsPND 21: 1.73;PND 56: 1.02;PND 91:0.91 μg/gPb-exposure had no effect on working memory at any age tested, but did affectreference memory (significant in females and nearly significant in males) in thePND 21 rats.Jett et al. (1997)

# AX5-27Table AX5-3.4 (cont’d). Summary of Key Studies on Neurobehavioral ToxicitySubjectExposureProtocolPeak Blood Pbor [Pb] UsedObserved EffectsReferenceRat, LE, male 750 ppm Pb(Ac)2maternally, permanently,or postweaning onlyAt PND 1001.8, 21.3, 22.8,and 26.3 μg/dLMaternal and permanent exposure: impaired water maze performance, withmaternal exposure producing both thegreatest escape latency and longestescape path length. No effects onperformance in the postweaning exposuregroups.Kuhlmann et al.(1997)Monkey,rhesusPb(Ac)2testing first 4 wks oflife35 μg/dL Pb-induced greater agitation, climbing, fear, and exploration of the periphery. Lasky and Laughlin(2001)Monkey,rhesus1 mg/kg/d Pb(Ac)2PND 5–PND 365First yr~70 μg/dL16-mo PE:~35 μg/dLFirst yr: Pb-induced disruption of social play, and increases in both self-stimulation and fearful behavior were observed. 16 mo: continueddisruption.Laughlin et al.(1991)Monkey,rhesusPb(Ac)2testing first 4 wks oflife35 μg/dL Few differences between controland Pb-exposed monkeys were seen; lessstability in SNAP performance.Laughlin et al.(1999)Monkey,rhesus,5–6 yrs10 mg/kg/d pulses (2) andchronic 0.7 for first yr of life250–300 μg/dLpeak80 for rest of yrPb-induced deficits occurred most commonly with short intertrial delays;lose-shift errors, possiblydue to perseveration.Levin and Bowman(1986)Monkey,rhesus,7–9 yrs10 mg/kg/d pulses (2) andchronic 0.7 for first yr of life1–4 wk:63 μg/dL5–6 wk: 1744 yrs: 47 yrs: 2Chronic L-dopa ameliorated the Pb-induced DSA deficits, which returnedfollowing cessation of L-dopa administration: implicates DA mechanisms inthese impairments.Levin et al. (1987)Monkey,rhesus10 mg/kg/d pulses (2) andchronic 0.7 for first yr of lifewk 5: 56 during;remainder of first6 mo: 33–43 μg/dLFirst 6 wks: Pb-induced lowered muscle tonus and greater agitation, noeffects on sensorimotor measures. PND 14: no Pb-related effects on objectpermanence task.2 mo: Pb-induced decreased visual attentiveness in visual exploration task.Levin et al. (1988)Monkey,rhesus350 or 600 ppmin utero50 and 110 μg/dL At age 12 to 15 mo, the high-dose group exhibited deficits in simplediscrimination learning: both groupsshowed impairments in the morecomplex learning set formation trials; activity at 12–15 mo showed noPb-related effects.Lilienthal et al.(1986)

# AX5-28Table AX5-3.4 (cont’d). Summary of Key Studies on Neurobehavioral ToxicitySubjectExposureProtocolPeak Blood Pbor [Pb] UsedObserved EffectsReferenceRat, SD, male,PND 608 or 16 mg Pb(Ac)26.8 μg/dL Long-lasting changes in drug responsiveness to cocaine and related drugs. Miller et al. (2001)Rat, Wistar 500 ppm Pb(Ac)2throughpregnancy and lactation41.24 μg/dL(dams),21.24 μg/dL(PND 23),<0.1 μg/dL(PND 70)PND 23: Pb-induced increased ambulation in the open-field tests, decreasedexploratory behavior in the holeboard tests, and no differences from control inthe elevated maze tests.PND 70: Pb-induced increase in head dipping in the holeboard test, decreasein social interaction time. No differences in the rotarod tests.Moreira et al.(2001)Rat, LE 75 or 300 ppm Pb(Ac)2continuously36 μg/dL Impaired learning of a visualdiscrimination task. Morgan et al.(2000)Rat LE,PND 53300 or 600 ppm duringgestation or gestation andlactationPND 8: 36–43;PND 24: 27–34;PND 53: 131–158No Pb-induced differences in learningrate, motivation, orresponse latencyfor correct or incorrect responses.Pb-induced: increases in errors ofomission when a delay was imposed prior to cue presentation, trials thatfollowed an incorrect response, and response initiation.Morgan et al.(2001)Rat, Wistartested atPND 100 andPND 142750 ppm though PND 16maternal exposure orchronicallyPND 110:maternallyexposed: <3;chronic:34 μg/dLBoth Pb-treated groups learned the original discrimination comparably tocontrols, but showed a deficit in retention; Pb-treated female rats took longerto reach criterion in the acquisition learning and longer to eat the pellets in theretention phase.Munoz et al. (1986)Rat, Wistar,female750 ppm Pb(Ac)217.3 μg/dL atPND 1632–39 μg/dLcontinuousexposurePb-induced deficits in acquisition oflearning, but not with concurrenthippocampal lesions. Four wks later, both lesioned and Pb-treated animalsshowed impaired retention.Munoz et al. (1988)Rat, Wistar,female750 ppm Pb(Ac)217.3 μg/dL atPND 1632–39 μg/dLcontinuousexposurePb and lesions of amygdala showed impairments in the acquisition phase ofthe maze and impaired passive avoidance; neither treatment affectedlocomotor activity. Continuously exposed rats showed greater deficits.Munoz et al. (1989)Rat, Wistar,PND 80400 mg/L Pb Cl2in dam’swater PND 1–30PND 8:10–15 μg/dL;PND 21: ~45;PND 80: 2–448 h PE: no Pb-induced changes in recall; 5 days PE: decline in recalllatency.Murphy and Regan(1999)

# AX5-29Table AX5-3.4 (cont’d). Summary of Key Studies on Neurobehavioral ToxicitySubjectExposureProtocolPeak Blood Pbor [Pb] UsedObserved EffectsReferenceRat, SD, male,adult500 ppm Pb(Ac)228.91 μg/dL Decreases sensitization to the locomotor-stimulating effects of cocaine. Nation et al. (1996)Rat, SD,PND 12016 mg Pb(Ac)2via gavage30 days pre-pregnancy toPND 2138.0 μg/dL Self-administering rats prenatallyexposed to Pb demonstrate and increasedsensitivity to the relapse phase of cocaine abuse.Nation et al. (2003)Rat, SD,PND 7016 mg Pb(Ac)2via gavage30 days pre-pregnancy toPND 2153.24 μg/dL Increased sensitivity to cocaine in ratsperinatally exposed toPb. Nation et al. (2004)Rabbit, DutchBelted, malePb(Ac)220, 40, and80 μg/dLExposed males mated with nonexposedfemales. Offspring at PND 25showed Pb-induced effects on exploratory behavior.Nelson et al. (1997)Monkey,squirrelMother's blood Pb fromgestation week 5–birth21–79 μg/dL Reduced sensitivity to changes in reinforcement contingencies duringbehavioral transitions and in steady state.Newland et al.(1994)Monkey,squirrelIn utero exposure21–70 μg/dLmaternalPb-induced increase in the number of responses that failed to adequatelydisplace the bar in the FR schedule and possible subtle motor impairments.Newland et al.(1996)Monkey,cynomolgus2 mg/kg/d of Pb(Ac)2continuously115 μg/dL atPND 10033 μg/dL byPND 270At PND 60: Pb-induced increased mean FR pause times, and, decreased FIpause times. At 3 yrs of age: Pb-induced increased FI run rate, pause time,and index of curvature. At both ages, Pb-induced increased variability ofperformance.Rice (1988a)Monkey,cynomolgus50 or 100 μg/kg/d Pb(Ac)2chronically beginningat PND 1PND 100: 15.4and 25.4PND 300: 10.9and 13.1 μg/dLDelayed alternation at 7–8 yrs of age: Pb-induced impairment of initialacquisition of tasks; longer delays between alternations resulted in poorerperformance and perseverative behavior, sometimes lasting for hours.Rice and Karpinski(1988)Monkey,cynomolgus,7–8 yr1500 μg/kg/d Pb(Ac)236 μg/dL Pb exposure in infancy only impaired spatial discrimination reversal tasks. Rice (1990)Monkey,cynomolgus,7–8 yr1500 μg/kg/d Pb(Ac)2continuously from birth,during infancy only, orbeginning after infancy36 μg/dL All Pb-treated groups: same impairments of initial acquisition, indiscriminateresponding, greater impairment withlonger delays, and preseverativeresponses.Rice and Gilbert(1990b)

# AX5-30Table AX5-3.4 (cont’d). Summary of Key Studies on Neurobehavioral ToxicitySubjectExposureProtocolPeak Blood Pbor [Pb] UsedObserved EffectsReferenceMonkey,cynomolgus,5–6 yr1500 μg/kg/d Pb(Ac)2continuously from birth, duringinfancy only, or beginning afterinfancy36 μg/dL Post-infancy exposure impairsnonspatial discrimination reversal whileexposure during infancy exacerbates the effect.Rice and Gilbert(1990a)Monkey,cynomolgus,3 or 7 yr1500 μg/kg/d Pb(Ac)236 μg/dL Pb exposure during different developmental periods produce different effectson F1 performance in juveniles versus adults.Rice (1992a)Monkey,cynomolgus,8–9 yr1500 μg/kg/d Pb(Ac)2continuously from birth, duringinfancy only, or beginning afterinfancy36 μg/dL Pb-treated monkeys in all threeexposure groups learned more slowly, withless impairment in infancy-only exposures, and showed perseverativebehavior.Rice (1992c)Monkey,cynomolgus,0.5 or 3 yr2000 μg/kg/d Pb(Ac)2115 μg/dL Decreased interresponse times and a greaterratio of responses perreinforcement on the differential reinforcement of low rate schedule.Rice (1992b)Rat, adult 16 mg Pb(Ac)2via gavage 30 days pre-pregnancy to PND 2183.2 μg/dL Developmental Pb exposure resultsin enhanced acquisition of cocaine self-administration.Rocha et al. (2005)Rat0.5, 2.0, or 4.0 mM Pb(Ac)2indrinking water11–50 μg/dL Pb-induced decreased retention inshuttle avoidance task. Pb-associatedincrease in locomotor activity.Rodrigues et al.(1996a)Rat, F344~42 μg/dL Pb-induced better performanceusing extra-maze spatial cues; Pb-treated ratsspent less time on the periphery of the maze.Salinas and Huff(2002)Rat, LE, male 0.2% Pb(Ac)2fromPND 25 until testing atPND 100~30 in Pb Pb-exposure + isolation: spatial learning deficits. Pb-exposure + enrichment:performed better than theisolated Pb group. Pb-induced decreases inhippocampal levels of BDNF, NGF-β, NT-3, and basic FGF.Schneider et al.(2001)Rat, Wistar 750 ppm Pb(Ac)2gestation and lactationPND 30:25 μg/dLPND 90:0.113 μg/dLAt PND 30 and 90: no Pb-associated changes in elevated maze behavior.PND 30: decreased freezing, increased ambulation, and increased grooming.PND 90: Pb-induced decreased freezing and increased ambulation.Offspring of Pb-treated females mated with nonexposed males.F2 generation at PND 30 and 90: increased ambulation and decreasedgrooming.Trombini et al.(2001)Rat, Wistar 0.03%, 0.09%,or 0.27%Pb(Ac)2gestationally~30, ~33, and~42 μg/dL atPND 0, tested atPND 49Male offspring: all three doses impaired memory retrieval. Female offspring:only the low dose affected memory retrieval. Motor performance and visionwere not affected by Pb.Yang et al. (2003)

# AX5-31Table AX5-3.5. Summary of Key Studies onCell Morphology and Metal DispositionSubject Exposure ProtocolPeak Blood Pbor [Pb] UsedObserved EffectsReferenceRat, PND 110 Water—0.2% Pb(Ac)2fromGD 16-PND 21 or useCReduction in hippocampal neurogenesis with no spatial learningimpairments.Gilbert et al. (2005)Rat C6 glioma cells and humanastrocytoma cells5–10 μM Pb(Ac)2Directly targets GRP78 and induces its compartmentalizedredistribution. GRP78 plays a protective role in Pb neurotoxicity.Qian et al. (2005a)Rat pup astroglial cell culture10 μM Pb(Ac)2Oxidative stress in astroglia results from Pb impairment of the Cutransporter Atpase (Atp7a).Qian et al. (2005b)Rat, PND 60 1500 ppm Pb(Ac)2for 30–35 days 20.0 μg/dL Significant deleterious effectson progenitor cell proliferation. Schneider et al.(2005)Rat,embryosCultured neurospheres 0.1–100 μMPb(Ac)2Differentially affects proliferation and differentiation of embryonicneural stem cells originating from different brain regions.Huang and Schneider(2004)Young rat PND 0–20 = 600 μg/dLPND 20–40 = 20–60 μg/dL131.3 μg/dL Blood Pb during succimer chelation are not an immediate indicatorof brain. Brain Pb values are slower to respond even though bloodPb is normal.Stangle et al. (2004)Cultured oligodendrite progenitorcells—PND 21 μM Pb(Ac)2Pb inhibition of proliferation and differentiation of oligodendrocytecells requires PKC.Deng and Poretz(2002)Cultured oligodendrite progenitorcells—PND 20.1–100 μMPb(Ac)2Interferes with maturation of oligodendrocyte progenitor cells. Deng et al. (2001)Cultured cerebellar granule neurons 5–50 μM Pb(NO3)2or Pb(ClO4)2Specific transport systems carry Pb into neurons. Mazzolini et al.(2001)Rat Cultured C6 glioma cells 1 μM Pb(Ac)2Induces GRP78 protein expression and GRP78 is a strong Pbchelator.Qian et al. (2000)Human,1–4 yrHalf-life of blood Pb was dependent upon exposure duration,ranging 10–38 mo.Manton et al. (2000)Rat and human Cultured rat astroglial,human neuroblastoma1 μM Pb(Ac)2Immature astroglia vs. neuronal cellsare most likely to bind Pb inthe brain.Lindahl et al. (1999)Review paper addressing Pb-binding proteins in the brain andkidney.Fowler (1998)Cultured GH3, C6, and HEK293cells1–10 μM Pb(NO3)2Cellular uptake of Pb is activated by depletion of intracellularcalcium.Kerper and Hinkle(1997)Rat 2 g/l Pb(Ac)2in weanlings for 3 mo 39 μg/dL Chronic low Pb levels induces blood brain barrier dysfunction. Strużyńska et al.(1997)

# AX5-32Table AX5-3.5 (cont’d). Summary of Key Studies on Cell Morphology and Metal DispositionSubject Exposure ProtocolPeak Blood Pbor [Pb] UsedObserved Effects ReferenceRat50 or 250 μg/mL Pb(Ac)2for 30, 60,or 90 days48.9 μg/dL Low dose, long-term exposure significantly decreases cerebralspinal fluid concentrations of TTR.Zheng et al. (1996)FrogtadpolesElvax implantation for 6 wks10!10to 10!6MPb Cl2Stunted neuronal growth from low Pb levels are reversible withchelator.Cline et al. (1996)RatCultured hippocampal neurons 100 nM Pb Cl2Possible neurite development inhibition via hyperphosphorylation. Kern and Audesirk(1995)Human Pb-binding proteins isolated fromcortex10–2000 nMPb(Ac)2Characterizes two cytosolic Pb-binding proteins-thymosin beta 4and an unidentified protein.Quintanilla-Vegaet al. (1995)RatsPND 7–60100–2000 ppm Pb(Ac)2in water foradult rats72.5 μg/dL Elimination half-life of Pbfrom all regions of the brain was about20 days. There was no evidence of selective regional accumulationof Pb.Widzowski andCory-Slechta (1994)Rat, adult Radiolabeled Pb perfused acrosswhole brain9.7 mL/100 g Review paper examining the passage of Pb across the blood-brainbarrier. Suggests it is activelytransported via Ca-ATP pump.Bradbury and Deane(1993)Review paper indicating that Pbeither structurally alters nuclearprotein p32/6.3 or inhibits a protease for which it is a substrate.Shelton et al. (1993)Review paper discussing Pb removal from bone; the half-life of Pbin bone is about 20 yr while in blood it is 1 mo.Wedeen (1992)Rat, adult Radiolabeled albuminCDiscovered that albumin rarely enters brain from blood. Bradbury et al.(1991)Guinea pig,chicken, andratMouse neuroblastoma2a cell lineCResults indicate a positive correlation between p32/6.3 levels andneuronal maturation.Klann and Shelton(1990)Dog and rat Mouse neuroblastoma2a cell line50–100 μM Pb Examined the relationship between Pb and nuclear protein p32/6.3and its abundance in intranuclear inclusion bodies.Klann and Shelton(1989)Adult rat Pb binding protein of kidneyand brain0.1–1.6 μM Attenuation of Pb inhibitionof ALAD involves sequestration of Pband a donation of zinc to the enzyme.Goering et al. (1986)RatPerfusion of 0.5 MBq of Pb-203isotope for 0.5–4 h615 μg/dL Injections of Pb-203 showed alinear uptake into three regions ofthe brain, suggesting that the blood-brain barrier is rate-limiting.Bradbury and Deane(1986)HumanC160 μg/100 mL Blood Pb half-life is affected by duration of exposure, age, andlength of follow-up.Hryhorczuk et al.(1985)HumanC>60 μg/dL Blood Pb half-life is dependent uponthe length of exposure. O’Flaherty et al.(1982)

# AX5-33Table AX5-3.6. Key Studies Evaluating Chelation of Pb in BrainSubject Exposure Protocol Chelator Observed Effects ReferenceRat, male, LE,PND 21Group 1: 50 ppm Pb acetate indrinking water from PND 21for 3–4 mo, after which theywere given i.p. injections of75 or 150 mg/kg CaEDTA foreither 1, 2, 3, 4, or 5 days.Group 2: 25 or 500 ppm Pbacetate followed by a singleinjection of either 75 or150 mg/kg CaEDTA. Twenty-four hour urine samples werecollected following CaEDTAinjections.CaEDTA Group 1: Blood Pb declined after the first CaEDTA injection, but did not dropfurther with subsequent CaEDTA andnever dropped below control levels(5 μg/dL). Pb levels in urine increasedsimilarly with both doses of CaEDTA.Pb was found to be mobilized from both bone and kidney and initiallyredistributed to brain and liver. Subsequent CaEDTA injections causeddeclines in brain and liver Pb levels, but no net loss of Pb.Group 2: a single injection of 150mg/kg CaEDTA caused marked elevationof brain Pb, which called into question use of injections of CaEDTA inclinical diagnostic procedures.Cory-Slechta et al.(1987)Rat, male, LE,PND 2150 ppm Pb acetate fromweaning until testing 3–4 molater. The rats received either25 or 50 mg/kg DMSA for 1, 2,3, 4, or 5 days and tissues wereevaluated 24 h following thelast injection.DMSA Blood Pb was decreased by DMSA dose-dependently, with levels dropping to<5 μg/dL after 3 injection of the higher dose and 4 injections of the lowerdose. Pb levels dropped in brain and kidney immediately, and in liverfollowing a delay. Bone Pb did notdecline, which contrasts with earlierstudies showing mobilization from bone following DMSA chelation. Anothergroup in this study received the same 5 days of DMSA injections, but wasevaluated 4 mo later. Pb concentrations in all tissues were comparable tothose seen in the first group, indicating that chelation therapy must becontinued to lower tissue Pb levels.Cory-Slechta (1988)Rat, female,WistarGiven206Pb-enriched drinkingwater at 210 ng Pb/mL for36 h. Following an overnightfast, the rats were injected withone 0.25 mL i.p. injection of0.11 mmol/kg DMSA. Pblevels in blood, kidney, brain,and tibia assessed 24 h later.DMSA Blood Pb declined 40%, Pb in urine increased 1500%, and changes in kidneyand brain tissue Pb levels varied inconsistently. Chelation did not result inincreased excretion of skeletal Pb compared to controls, nor did it show aredistribution of Pb to brain.Smith and Flegal(1992)

# AX5-34Table AX5-3.6 (cont’d). Key Studies Evaluating Chelation of Pb in BrainSubject Exposure Protocol Chelator Observed Effects ReferenceRat, female,Albino100 ppm Pb acetate in drinkingwater for 4 wks. During the last 2days of that exposure, the rats wereadministered two i.p. injections of 1μg stable204Pb tracer. Animals thenreceived 1 to 5 consecutive days of150 mg/kg CaEDTA ; assayed 24 hfollowing the last injection.CaEDTA No redistribution of endogenous Pb into the brain following oneCaEDTA dose, no measurable reductionin brain or bone Pb levels, andreductions in both kidney and blood Pblevels. Additionally, over thefirst day of treatment, CaEDTA reduced the204Pb tracer moreeffectively than the Pb from chronic exposure, indicating greaterbiologically availability of Pb from recent exposures.Seaton et al. (1999)Rat, male, SDrats at 6–7 wksChelation with ongoing Pbexposure; blood Pb were ~45 μg/dL;550 ppm Pb acetate in drinkingwater for 35 days.Group 1: continued on Pb only for21 days.Group 2: received continued Pbplus oral DMSA at16, 32, 120, or240 mg/kg/d for 21 days.Group 3: discontinued on Pb afterthe first 35 days and received oralDMSA (16, 32, or 240 mg/kg/d).DMSA DMSA treatment increased urinary Pb and decreased levels of Pb inblood, brain, bone, kidney, and liver, even with continued Pb exposure.Pappas et al. (1995)Rat, male,WistarDosed with 1000 ppm Pb indrinking water for 4 mo, then treatedfor 5 days with: saline; 25 mg/kgDMSA orally, twice daily; 75 mg/kgCaEDTA i.p. once daily; or25 mg/kg DMSA twice daily plus75 mg/kg CaEDTA i.p. once daily.Blood Pb resulting from thesetreatments were 46, 22, 28, and 13μg/dL, respectively and brain Pblevels were 49, 38, 26, and 22 μg/g,respectively.CaEDTA andDMSAThe combined treatments produced an additive response in urinary Pbelimination and elimination from blood, liver, kidney, brain, and femur.Flora et al. (1995)

# AX5-35Table AX5-3.6 (cont’d). Key Studies Evaluating Chelation of Pb in BrainSubject Exposure Protocol Chelator Observed Effects ReferenceRat, female,LEGroup 1: 325 μg/mL Pbacetate maternally throughweaning, and then to 30 μg/mLuntil PND 30. Chelationtreatment consisted of 7 days of30 or 60 mg/kg/d DMSA.Group 2: 325 μg/dLmaternally and throughPND 40 and then treated toDMSA for 7 or 21 days.DMSA Seven days of DMSA effectivelyremoved Pb from both blood and brain.Treatment beyond 7 days further reduced brain Pb, but not blood Pb.Reductions in Pb were greater in the second group, which the authors attributeto the higher exposures used. The authors also hypothesize that DMSA-mediated reduction in blood Pb are a poorindicator of reductions in brain Pb.Smith et al. (1998)Rat, LE Exposed gestationally to600 μg/mL Pb acetate, thensplit into high and low dosegroups.Low dose group: 20 μg/mLfrom PND 21–28, followed by30 μg/mL from PND 29–40.High dose group: 40 μg/mLfrom PND 21–28, followed by60 μg/mL from PND 29–40.DMSA treatment consisted of50 mg/kg/d for 1 wk, then25 mg/kg/d for 2 wks. Ratsreceived either 1 or2 treatments at PND 40 or40 and 70.DMSA One treatment lowered both blood Pb and brain Pb, but the brain reductionslagged the blood reductions both temporally and in magnitude. Following thesecond DMSA treatment, they observeda rebound in blood, but not brain Pblevels.Stangle et al. (2004)

# AX5-36Table AX5-3.6 (cont’d). Key Studies Evaluating Chelation of Pb in BrainSubject Exposure Protocol Chelator Observed Effects ReferenceMonkey,Rhesus,11-yr-old withhistory oftesting foreffects ofhousing andrearing andwhich wereused in drugchallengestudies, wereused after atleast 1.5 yrshad elapsedsince the lasttesting~50 mg/kg/d Pb acetate, andthen doses were adjusted toproduce a target blood Pb of35–40 μg/dL. Following 5 wksof Pb exposure, the monkeyswere administered204Pb tracerstarting 4 days before chelation.DMSA was administered for5 days at 30 mg/kg/d, followedby 14 days at 20 mg/kg/d.DMSA Brain levels of Pb and tracer, measured in prefrontal cortex, hippocampus, andstriatum, were not different from controls, indicating that DMSA was noteffective in reducing brain Pb levels. They also found a poor correlationbetween brain and blood Pb levels.Cremin et al. (1999)Rat, male, LE,PND 55At PND 55, rats were started onan FI schedule, where a Pb-induced increase ininterresponse time wasobserved. Pb exposure wasthen terminated and dailyinjections of 75 or 150 mg/kgCaEDTA were given for5 consecutive days.CaEDTA Chelation treatment failed to reverse the learning deficits in Pb-exposedanimals and further increased the proportion of short interresponse times. Theauthors suggest that this effectmay be due to the CaEDTA-mediatedredistribution of Pb from bone to brain.Cory-Slechta andWeiss (1989)Rat, male,F344, 7-wk-old male150 or 2000 ppm Pb for21 days, then distilled water forthe next 21 days. Blood Pbpeaked at 37 and 82 μg/dL,respectively. Chelation:50 mg/kg by oral gavage,3 times a week for up to21 days; reduced blood Pb to22 and 56 μg/dL, respectively.DMSA Pb-induced increase in rearing behavior was observed. DMSA reduced thePb-induced effects on activity. Levels ofbrain glial fibrillary acidic protein(GFAP) were also assessed in theseanimals. A Pb-induced dose-dependentincrease in GFAP was observed inhippocampus, cortex, and cerebellum,which was reversedby DMSA treatment.Gong and Evans(1997)

# AX5-37 

# ANNEX TABLES AX5-4

# AX5-38Table AX5-4.1. Effect of Lead onReproduction and Development inMammals Effects on OffspringCitationSpecies/Strain/AgeDose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Al-Hakkaket al. (1988)Mouse/BALB/c,weaning0, 25, 50 mg Pb monoxidealloy/kg in chow for 35–70 daysReduced number of spermatogenia and spermatocytes in the 50 mg group after 70 days;reduced number of implantations after mating (after 35 days exposure).PbB not reportedAppleton(1991)Rat/Long-Evanshooded, adultPb acetate single dose by i.v. at30 mg/kgIncrease in serum calcium and phosphorous; SEManalysis revealed‘Pb line’ in tooththat was composed of hypomineralized interglobular dentine.PbB not reportedBatainehet al. (1998)Rat/Sprague-Dawley, adult1000 ppm Pb acetate indrinking water for 12 wksFertility was reduced; total number of resorptions was increased in female ratsimpregnated by males.PbB not reportedBerry et al.(2002)Rat/Sprague-Dawley, 21 daysoldPb nitrate (1000 ppm Pb)in drinking water for 6 wksMean plasma growth hormone levels decreased by 44.6%; reduced mean growthhormone amplitude by 37.5%, mean nadir concentration by 60%, and growth hormonepeak area by 35%; findings are consistentwith decreased hypothalamic growthhormone-releasing factor secretion or reduced somatotrope responsiveness; exogenousgrowth hormone in Pb-treated and controlrats, this response was blunted by the Pbtreatment; plasma IGF1 concentration was notsignificantly affected by Pb treatment.PbB 37.40 ± 3.60 μg/dLBogden et al.(1995)Rat/Sprague-Dawley, 12 wksold250 mg/L of Pb acetate indrinking water from GD 1 untilafter 1 wk after weaningDam and pup hemoglobin concentrations, hematocrit, and body weights and lengthswere reduced.PbB <15 μg/dLCamorattoet al. (1993)Rat/Sprague-Dawley, adult0.02% Pb nitrate in drinkingwater from gestation day 5 ofdams until PND 4 of offspringFemale pups exposed to Pb beginning in utero were smaller, no corresponding effect inmales; pituitary responsiveness to a hypothalamic stimulus.PbB 17–43 μg/dLCorpas(2002a)Rat/Wistar, adult Pb acetate 0 or 300 mg/L indrinking water during gestationand lactationAlterations in hepatic system of neonates (PND 12) and pups (PND 21); reductions inhemoglobin, iron, alkaline and acid phosphatase levels, and hepatic glycogen, andelevated blood glucose.PbB ~22 μg/dLCorpas(2002b)Rat/Albino(NOS), adultPb acetate 0 or 300 mg/L indrinking water during gestationand lactationEffects energy metabolism; decrease in testis and seminal vesicle weights, and anincrease in DNA and RNA levels on PN day 21; protein was significantly decreased,alkaline and acid phosphatase levels of the gonads were reduced; reduction of thethickness of the epithelium and seminiferous tubule diameter.PbB 54–143 μg/dL

# AX5-39Table AX5-4.1 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on OffspringCitationSpecies/Strain/AgeDose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Cory-Slechtaet al. (2004)†Rat/Long-Evans,adultPb acetate in drinking water(150 ppm); 2 mo beforebreeding until the end oflactation14 rats no maternal stress Pbexposure, 15 rats no maternalstress with Pb exposure, 18 ratsmaternal stress without Pbexposure, 23 rats maternalstress and Pb exposurePb alone (in male) (p < 0.05) and Pb plusstress (in females) (p < 0.05) permanentlyelevated corticosterene levels in offspring.PbB 30–40 μg/dLDey et al.(2001)Mouse/Albino(NOS), ~100 gPb citrate 5 μg/kg-d p.o. fromearly pregnancy (NOS) untilbirthPerforations, tissue damage, cell deformity,disordered organization of collagen bundlesfound in offspring; reduction in the symmetry of sulphate group of skin pups of miceexposed to Pb citrate (5 μg/kg-d) throughout gestation exhibited a variety of skinanomalies, including perforations, tissuedamage, cell deformity, and disorderedcollagen bundles Pb was found to affect initial genomic expression in embryos fatheredby male rats.PbB not reportedFlora andTandon (1987)Rat/Albino(NOS), adultPb nitrate dissolved in water 2–20 mg/kg-d i.v. on day 9, 10,11 of gestation; 6 rats in eachgroup (0, 5, 10, 20, 40 mg/kgPb)Dose-dependant increase in external malformations at all doses (p < 0.001), particularlytail defects; dose dependant decrease in number of live births at 20 and 400 mg/kg(p < 0.001); dose-dependent increase innumber of resorptions per dam at#10 mg/kg(p < 0.01).PbB 13–45 μg/dLFox et al.(1991a)Rat/Long-Evanshooded, adultLactation exposure via damsexposed to 0.02 or 0.2% Pb indrinking water from PND 1through weaning (PND 21)8 female pups per litter(number of litter unspecified)control pups, 8 pups for litter(number of litter unspecified)low level exposure pups,8 pups per litter (number oflitter unspecified) moderatelevel exposure pupsLong-term, dose-dependent decreases retinalNa/K ATPase activity in the femaleoffspring (only female pups were used) (!11%;!26%) (p < 0.05).PbB 18.8 or 59.4 μg/dL atweaning

# AX5-40Table AX5-4.1 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on OffspringCitationSpecies/Strain/AgeDose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Fox et al.(1997)†Rat/Long-Evanshooded, adult0.02 or 0.2% Pb acetate indrinking water from PND 0–PND 21; 8 female pups perlitter control pups; 8 pups perlitter low level exposure;8 pups per litter moderate levelexposure (number of litters perdose unspecified)Developmental and adult Pb exposure for 6 wks produced age and dose-dependentretinal degeneration such that rods and bipolar cells were selectively lost; at theultrastructural level, all dying cells exhibit the classical morphological features ofapoptotic cell death; decrease in the numberof rods was correlated with the loss ofrhodopsin content per eye confirming that rodswere directly affected by Pb (p < 0.05);single-flash rod ERGs and cone ERGs obtained from Pb-exposed rats demonstrated thatthere were age- and dose-dependent decreasesin the rod a-wave and b-wave sensitivityand maximum amplitudes withoutany effect on cones; in adult rats exposed to Pb for3 wks, qualitatively similar ERG changes occurred in the absence of cell loss ordecrease in rhodopsin content (p < 0.05);developmental and adult Pb exposure forthree and 6 wks produced age- and dose-dependent decreases in retinal cGMPphosphodiesterase (PDE) activity resulting in increased CGMP levels (p < 0.05); retinasof developing and adult rats exposed to Pbexhibit qualitatively similar rod mediatedERG alterations as well as rod and bipolar apoptotic cell death (p < 0.05); similarbiochemical mechanism such as the inhibition of rod and bipolar cell cGMP PDE,varying only in degree and duration, underlies both the Pb-induced ERG rod-mediateddeficits and the rod and bipolarapoptotic cell death (p < 0.05).PbB weanlings 19 ± 3 (lowexposure) or 59 ± 8 μg/dL(moderate exposure), adult7 ± 2 μg/dL (at PND 90)Gandley et al.(1999)Rat/Sprague-Dawley, adultMale rats exposed to 25 or250 ppm acetate Pb in drinkingwater for at least 35 days priorto breedingFertility was reduced in males with PbB inrange 27–60 μg/dL, Pb was found to affectinitial genomic expression in embryos fatheredby male rats with blood Pb levels as lowas 15–23 μg/dL; dose-dependant increases wereseen in an unidentified set of proteinswith a relative molecular weight of ~70 kDa.PbB 27–60 μg/dL (fathers)15–23 μg/dL (offspring)Govoni et al.(1984)Rat/Sprague-Dawley, adult2.5 mg/mL Pb acetate indrinking water from GD 16 topostnatal week 8Decreased sulpiride binding in the pituitary isconsistent with the elevated serum PRLconcentrations previously described in Pb-exposed rats; DOPAc concentrations werereduced by 21% inPb-treated rats.PbB 71 ± 8 μg/dLHamilton et al.(1994)Rat/Sprague-Dawley,25 days oldPb acetate in drinking water at250, 500 or 1000 ppm; 8 wksprior to mating through GD 21Altered growth rates; reduced early postnatal growth; decreased fetal body weight. PbB 40–100 μg/dLHan et al.(2000)Rat/Sprague-Dawley, 5 wksold250 mg/mL Pb acetate indrinking water for 5 wksfollowed by 4 wks no exposure(mated at end of 4-wk noexposure period)Pups born to Pb-exposed dams had significantly (p < 0.0001) lower mean birth weightsand birth lengths.PbB 10–70 μg/dLHanna et al.(1997)Mouse/SwissICRpreimplantationembryosIn vitro incubation of two- andfour-cell embryos with 0.05–200 μM Pb acetate for 72 hr(time required for blastocystformation)Exposure of embryos to Pb was only toxicat 200 μM, which reduced cell proliferationand blastocyst formation.PbB not reported

# AX5-41Table AX5-4.1 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on OffspringCitationSpecies/Strain/AgeDose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Iavicoli et al.(2003)Mouse/Swiss,adultPb acetate in food (0.02, 0.06,0.11, 0.2, 2, 4, 20, 40 ppm)exposure began 1 day aftermating until litter was 90 daysold one litter of mice exposedto each dietary concentrationLow-level exposure (PbB 2–13 μg/dL) reduced red cell synthesis (p < 0.05); high-levelexposure (PbB 0.6–2 μg/dL) enhanced red cell synthesis (p < 0.05).PbB 0.6 to <2.0 μg/dL or>2.0–13 μg/dLIavicoli et al.(2004)Mouse/Swiss,adultPb acetate in feed; exposurebegan 1 day after mating untillitter was 90 days oldIn females: accelerated time to puberty atPbB <3 μg/dL; delayed time to puberty at3–13 μg/dL.PbB 0.6 to <2.0 μg/dL or>2.0–13 μg/dLLögdberget al. (1987)Monkey/Squirrel, adultPb acetate p.o. exposure ofgravid squirrel monkeys fromweek 9 of gestation throughPND 0Increase in pre- and perinatal mortality among squirrel monkeys receiving Pb acetatep.o. during the last two-thirds of pregnancy (45% vs. 7–8% among controls); meanmaternal PbB was 54 μg/dL (39–82 μg/dL); statistically significant reductions in meanbirth weight were observed in Pb-exposed monkeys as compared to controls; effectsoccurred without clinical manifestation of toxic effects in the mothers.PbB 54 μg/dL (39–82 μg/dL)Lögdberget al. (1998)Monkey/Squirrel, adultPb acetate (varyingconcentrations#0.1% in diet);maternal dosing from 5–8.5 wks pregnant to PND 1;11 control monkeys, 3 low-Pbexposure group (PbB24 μg/dL), 7 medium Pb group(PbB 40 μg/dL, 5 high-Pbgroup (PbB 56 μg/dL)Dose-dependent reduction in placental weight(p < 0.0007); various pathological lesionswere seen in the placentas (n = 4), including hemorrhages, hyalinization of theparenchyma with destruction of the villiand massive vacuolization of chorionepithelium; effects occurred without clinicalmanifestation of toxic effects in themothers.Mean maternal PbB 37 μg/dL(22–82 μg/dL)24 (22–26) μg/dL (low dose)40 (35–46) μg/dL (mid dose)56 (43–82) μg/dL (high dose)McGivernet al. (1991)†Rat/Sprague-Dawley, adult0.1% Pb acetate in drinkingwater from GD 14 toparturitionMale offspring of dams exhibited reducedsperm counts, altered male reproductivebehavior, and enlarged prostates later inlife; females exhibited delayed puberty,menstrual irregularities, and an absence ofobservable corpora lutea; males and femalesexhibited irregular release patternsof both FSH and LH later in life.PbB 73 μg/dLNayak et al.(1989a)Mouse/SwissWebster, adultPb nitrate dissolved in NaClsolution, administeredintravenously, via caudal veinat dose levels of 100, 150,200 mg/kg; one time exposureon GD 9Chemical analysis showed Pb was readilytransferred across placenta; Pb causedmoderate, statistically significant, increasein frequency of SCEs in maternal bonemarrow cells and significant reduction in NORs at the 2 highest dose levels (150 and200 mg/kg); animals showed several specific chromosomal aberrations, mostlydeletions, in maternal bone, marrow, andfetal cells; aneupoidy was found to befrequently associated with the lowest doselevels of Pb nitrate (100 mg/kg); increasedembryonic resorption and reduced placental weights.PbB levels at birth in theexposure groups for thesestudies were >180 μg/dLPiasek andKostial (1991)Rat/Wistar,10 wks old7500 ppm Pb acetate indrinking water for 9 wksDecrease in litter size, pup survival, and birth weight; food consumption, body weight,and fertility were not altered in 20 wk exposure period.Maternal PbB >300 μg/dLOffspring PbB >220 μg/dL

# AX5-42Table AX5-4.1 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on OffspringCitationSpecies/Strain/AgeDose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Pinon-Latailladeet al. (1995)Mouse/NMRI,adult0–0.5% Pb acetate indrinking water exposed to Pbduring gestation until post-GD 60Pb exposure during gestation reduces litter size; reducedbirth weight and growth rates. PbB <4–132 μg/dLPillai andGupta (2005)Rat/CharlesFoster,200–220 gSubcutaneous injection of0.05 mg/kg-d Pb acetate for5–7 days prior to matingthrough PND 21Long term exposure of rats (premating, gestational, and lactational) to moderate levelsof Pb acetate (s.c.) resulted in reduced activities of hepatic steroid (E2) metabolizingenzymes (17-ß-hydroxy steroid oxidoreductaseand UDP glucuronyl transferase) anddecreased hepatic CYP450 content.PbB not reportedRonis et al.(1996)†Rat/Sprague-Dawley, 22,55 days or plug-positive time-impregnated0.6% Pb acetate in drinkingwater for various durations:PND 24–74 (pubertalexposure), PND 60–74 (postpubertal exposure); 11 malesand females in pubertalexposure group (10 each incontrol pubertal group);6 males and females post-pubertal exposure and controlgroupsReduction in serum testosterone levels inmale, not female; in female suppression ofcirculating E2 (p < 0.05) and LH (p < 0.05); reduction in male secondary sex organweight (p < 0.0005); delayed vaginal opening and disrupted diestrous in females(p < 0.005); increased incidence of stillbirth (2% control vs. 19% Pb) (p < 0.005).In utero PbB 250–300 μg/dLPre-pubertal PbB 30–60 μg/dLPost-pubertal PbB 30–60 μg/dLPbBs in the dams and offspringin this experiment were>200 μg/dL.Ronis et al.(1998a)†Rat/Sprague-Dawley, variousages0.6% Pb acetate in drinkingwater ad libitum for variousdurations: GD 5 to PND 1,GD 5 to weaning, PND 1 toweaning3 control litters, 2 gestationexposure litters, 2 lactationexposure litters, 2 gestationand lactation exposure litters,2 postnatal litters, 2 chroniclitters (4 male and 4 femalepups per litter)Dose-dependent delay in sexual maturation (delayed vaginal opening) (p < 0.0002)following prenatal Pb exposure that continued until adulthood (85 days old); reducedbirth weight (p < 0.05), more pronounced among male pups.Group: pup PbBNaïve: ~6 μg/dLControl: <2 μg/dLGest: ~10 μg/dLLact: ~3 μg/dLGest+Lact: ~13 μg/dLPostnatal: ~260 μg/dLChronic: ~287 μg/dLRonis et al.(1998b)†Rat/Sprague-Dawley, adultPb acetate in drinking water(0.05% to 0.45% w/v); damsexposed until weaning,exposure of pups whichcontinued until PND 21, 35,55, or 85; 5 control litters(0%), 10 low-dose litters(0.05%), 8 mid-dose litters(0.15%), 9 high-dose litters(0.45%); 4 male and 4 femalepups per litterPrenatal Pb exposure that continues untiladulthood (85 days old) delays sexualmaturation in female pups in a dose-related manner (p < 0.05); birth weight reduced(p < 0.05), more pronounced among male pups; decreased growth rates (p < 0.05) inboth sexes accompanied by decrease in plasmaconcentrations of IGF1 through puberty(p < 0.05) and a significant increase in pituitary and growth hormone during puberty(p < 0.05).PbBs in the pups between theages of 21 and 85 days were>100 μg/dL and reached up to388 μg/dL.

# AX5-43Table AX5-4.1 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on OffspringCitationSpecies/Strain/AgeDose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Ronis et al.(1998c)Rat/Sprague-Dawley, adultPb acetate 0.05, 0.15, or0.45% in drinking waterbeginning GD 5 continuinguntil PND 21, 35, 55, or 85;5 control litters (0%),10 low-dose litters (0.05%),8 mid-dose litters (0.15%),9 high-dose litters (0.45%);4 male and 4 female pupsper litterDose-responsive decrease in birth weight (p < 0.05), and crown-to-rump length(p < 0.05); dose-responsive delay in sexual maturity in male (p < 0.05) and female(p < 0.05); neonatal decrease in sex steroids (p < 0.05); pubertal decrease intestosterone (male) (p < 0.05) and E2 (female) (p < 0.05); decrease estrous cyclicity athigh dose (p < 0.05).Dams: 0, 48, 88, or 181 μg/dLPups PND 1: <1, ~40, ~70, or>120 μg/dLPups PND 21: <1, >50, >160, or~237 μg/dLPups PND 35: <1, ~22, >70, or>278 μg/dLPups PND 55: <1, >68, >137, or~380 μg/dLPups PND 85: <1, >43, >122, or>214 μg/dLRonis et al.(2001)†Rat/Sprague-Dawley,neonate, male(100 days) andfemale pupPb acetate in drinking waterto 825 or 2475 ppm adlibitum from G'D 4 to GD 55postpartum; 1 male andfemale pup/litter (5 litters pergroup) control group, 1 maleand female pup/litter (5 littersper group) 825 ppm Pbacetate group, 1 male andfemale pup/litter (5 litters pergroup) 2475 ppm Pb acetategroupDose-dependent decrease of the load of failure in male (p < 0.05); no difference inplasma levels of vitamin D metabolites;reduced somatic growth (p < 0.05),longitudinal bone growth (p < 0.05), and bone strength during the pubertal period(p < 0.05); sex steroid replacement did not restore skeletal parameters in Pb exposedrats; L-Dopa increased plasma IGF1concentrations, ratesof bone growth, and bonestrength measures in controls while havingno effect in Pb exposed groups; DO gap x-ray density and proximal new endostreal bone formation were decreased in thedistration gaps of the Pb-treated animals (p< 0.01); distraction initiated at 0.2 mm 30 to60 days of age.PbB at 825 ppm was 67–192 μg/dLPbB at 2475 ppm was 120–388 μg/dLSant'Ana et al.(2001)Rat/Wistar,90 days old0.1 and 1% Pb in drinkingwater7 days1% Pb exposure reduced offspring body weight during treatment, no changes observedafter 0.1% exposure; no altered offspring sexual maturation, higher Pb improved sexualbehavior, while 0.1% reduced it; 0.1% Pb caused decrease in testis weight, an increasein seminal vesicle weight, and no changes in plasma testosterone levels, hypothalamicVMA levels were increased compared tocontrol group; reduced birth weight andgrowth rates.PbB 36.12 — 9.49 μg/dL or13.08 ± 9.42 μg/dLSingh et al.(1993b)Rat/ITRC,albino (NOS),6 wks old250, 500, 1000, and 2000ppm Pb nitrate in drinkingwater from GD 6 to GD 14Significantly reduced litter size, reduced fetal weight, and a reduced crown-to-rumplength, increased resorption and a higherblood-Pb uptake in those groups receiving1000 and 2000 ppm Pb; these also had a higher placental uptake; however the level wasthe same in both groups; fetal Pb uptake remained the same whether or not 2000 ppmPb was given to an iron-deficient or normal iron groups of mothers.PbB not reportedWatson et al.(1997)Rat/Sprague-Dawley, adultPb in drinking water at34 ppm from weaning ofmothers through gestationand weaning of offspringuntil birth; 6 pups controlgroup, 6 pups experimentalgroupReduced body weight (p = 0.04); parotid function was decreased by nearly 30%(p = 0.30); higher mean caries scores than the control pups (p = 0.005); pre- andperinatal Pb exposure had significantly increased susceptibility to dental caries(p = 0.015).PbB 48 ± 13 μg/dL

# AX5-44Table AX5-4.1 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on OffspringCitationSpecies/Strain/AgeDose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Wiebe et al.(1998)Rats/Sprague-Dawley, adult20 or 200 ppm Pb chloride indrinking water; prior topregnancy, during pregnancy,lactationExposure to Pb did not affect tissue weights but did cause a significant decrease ingonadotropin-receptor binding in the prepubertal, pubertal, and adult females;conversion of progesterone to androstenedione and dihydrotestosterone wassignificantly decreased in 21-day old rats, in150-day old females, the exposure to Pbresulted in significantly increased conversion to the 5-alpha-reduced steroids, normallyhigh during puberty.PbB 4.0 ± 1.4 to 6.6 ± 2.3 μg/dL*Not including effects on the nervous or immune systems.†Candidate key study.cGMP, cyclic guanosine—3',5'-monophosphate; DO, distraction osteogenesis; DOPAc, 3,4-dihydroxyphenylacetic acid; E2, estradiol; ERG, electroretinographic; FSH, follicle stimulating hormone;GD, gestational day; IGF1, insulin-like growth factor 1; i.v., intravenous; kDA, kilodalton; LH, luteinizing hormone; NOS, not otherwise specified; PbB,blood Pb concentration; PDE,phosphodiesterase; PND, post-natal day; p.o., per os (oral administration); s.c., subcutaneous; SEM, standard error mean; UDP,uridine diphosphate; VMA, vanilmandelic acid

# AX5-45Table AX5-4.2. Effect of Leadon Reproduction and Development in Mammals Effects on MalesCitationSpecies/Strain/Age Dose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Acharya et al.(2003)Mouse/Swiss,6–8 wks old200 mg/kg Pb acetate throughi.p. injection of Pb; one timeinjectionTesticular weight loss with constant increase in the incidence of abnormal spermpopulation; decrease in sperm count; testicularascorbic acid also declined significantly;significant rise in LPP of tissue; LPP is indicative of oxidative stress in treated micetestes.Not reportedAdhikari et al.(2000)Rat/Druckrey,28 days old0.0, 0.4, 4.0, 40.0 μM Pbacetate in vitro for 24 and48 hrGerm cells progressively detached fromSertoli cell monolayer into medium in aconcentration and duration dependent manner Viability ofthe detached cells showed adecrease with increase in timeand concentration of Pb; leakage of LDH recorded athigher dose of 4.0 and 40.0 μM.PbB not applicable–in vitro studyAdhikari et al.(2001)Rat/Druckrey,28 days old5, 10, and 20 mg/kg Pb indistilled water by gavage for2 wksInduced significant numbers of germ cellsto undergo apoptosis in the semiferoustubules of rats treated with highest dose; DNAfragmentation was not detected at any ofthe doses; level of Pb accumulation in testes increased in a dose-dependent manner.PbB not reportedAlexaki et al.(1990)Bulls/Holstein,3–5 yrs oldIn vitro fertilization 2.5 or0.25 μg/mLSperm motility reduced significantly at 2.5 μg/mL; lower concentration had no effecton sperm motility.PbB not applicable–in vitro studyAl-Hakkaket al. (1988)Mouse/BALB/c,weaning0, 25, 50 mg Pb monoxidealloy/kg in chow for 35–70 daysReduced number of spermatogenia and spermatocytes in the 50 mg group after 70 days;reduced number of implantations after mating (after 35 days exposure).PbB not reportedBarratt et al.(1989)Rat/Wistar,70 days old0, 0.3, 33, 330 mg Pbacetate/kg-d in drinkingwater, by gavage for 63 daysIncreased number of abnormal post-testicular sperm in the highest exposure group;reduced number of spermatozoa at PbB >4.5 μg/dL.PbB 2, 4.5, 7, 80 μg/dLPbBs >40 μg/dLBataineh et al.(1998)Rat/Sprague-Dawley, adult1000 ppm Pb acetate indrinking water for 12 wksFertility was reduced in males.PbB not reportedBatra et al.(2001)Rat/Portan,8 wks old10, 50, 200 mg/kg Pb acetateorally for 3 moPb in testis and epididymis increased withdose; administration of zinc reduced Pblevels; dose related changes in activities ofenzyme alkaline phosphatase and Na+-K+-ATPase, which decreased with increased dose of Pb; improvement in activities ofenzymes was seen in groups given Pb and zinc; disorganization and disruption ofspermatogenesis with accumulation of immaturecells in lumen of tubule; highest doseof Pb resulted in arrest of spermatogenesis, and decreasein germ cell layer population;highest dose levels, damage of basement membrane, disorganization of epithelium andvacuolization cells; tubules were foundalmost empty, indicating arrest ofspermatogenesis.PbB not reportedBatra et al.(2004)Rat/Portan,8 wks old10, 50, 200 mg/kg Pb acetateorally for 3 moLH and FSH concentrations were decreased at 200 mg/kg; decrease in fertility status at200 mg/kg; decline in various cell populations at 200mg/kg; 50 mg/kg group hormonelevels, cell numbers, and fertility status were found close to normal.PbB not reportedBizarro et al.(2003)Mouse/CD-1,adult0.01 M Pb acetate twice aweek for 4 wksDose-time relationship was found; ROS role.PbB not reportedBoscolo et al.(1988)Rat/Sprague-Dawley,weanling60 mg Pb acetate/mL indrinking water for 18 moIncreased vacuolization in Sertoli cells;no other ultrastructural modifications; noimpairment of spermatogenesis.PbB 4–17 μg/dL

# AX5-46Table AX5-4.2 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on MalesCitationSpecies/Strain/Age Dose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Chowdhuriet al. (2001)Mouse/BALB/c,3 mo old0.0, 0.2, 0.5, 1.0, 2.0 μg/mLPb acetate in culture mediumfor 2 hr (superovulated ovaand sperm)Significant dose dependent decrease in the number of sperm attaching to the ova in bothexposed groups; decrease in the incorporation of radio-labeled thymdine, uridine, andmethionine.PbB not applicable–in vitro studyChowdhuryet al. (1984)Rat/Albino,(NOS), adultDietary concentrations of0.25, 0.50, or 1.0 g/L Pbacetate for 60 daysTesticular atrophy along with cellular degeneration was conspicuous at 1 g/L; highcholesterol concentration and significantly low ascorbic acid concentration were foundin the testes at 1 g/L; lowest dose (0.25 g/L) had no significant morphological andbiochemical alterations, whereas as 0.5g/L resulted in partial inhibition ofspermatogenesis.PbB 54–143 μg/dLChowdhuryet al. (1986)Rat/NOS, adult 0, 1, 2, 4, 6 mg Pbacetate/kg-d i.p.for 30 daysDose-related decrease of testis weight; at 187μg/dL: degenerative changes in testiculartissues; at 325 μg/dL: degenerative changes and inquiry of spermatogenetic cells;edematous dissociation in interstitial tissue.PbB 20, 62, 87, 187, or325 μg/dLChowdhuryet al. (1987)Rat/CharlesFoster,150 ± 5 g0, 1, 2, 4, 6 mg Pbacetate/kg-d/i.p.for 30 daysDose related decrease oftestis weight at 56μg of spermatoids; at 91 μg/dL: inhibitionof post-meiotic spermatogenic cell; at 196 μg/dL: decreased spermatogenic cell count(6), detachment of germinal call layers;at 332 μg/dL: Decreased spermatogenic cellcount, degenerative changes, Interstitialedema, and atrophy of Leydig cells.PbB 56–3332 μg/dLCoffigny et al.(1994)†Rat/Sprague-Dawley, adultInhalation exposure to5 mg/m3Pb oxide daily for13 days during gestation(GD 2, 3, 6–10, 13–17, 20)Adult male offspring exhibit no change insperm parameters or sex hormones T, FSH,and LH (because of duration or timing).PbB 71.1 μg/dL (dam)PbB 83.2 μg/dL (fetal)Corpas et al.(1995)Rat/Wistar,adult300 mg/L Pb acetate viadrinking water beginning GD1 through 5 days postnatal orthroughout gestation andearly lactationTesticular weight and gross testicular structure were not altered; seminiferous tubulediameter and the number of prospermatogonia were reduced; total DNA, RNA, andprotein content of the testes in treatedrats was significantly reduced, DNA:RNA ratioremained unaltered.PbB 14 μg/dLCorpas et al.(2002a)Rat/Wistar,adult300 mg/L acetate Pb indrinking water beginning atmating until PND 12 and 21Neither abnormalities in the liver structure nor depositions of Pb, toxicant producedbiochemical alterations; pups exhibited decrease in hemoglobin, iron and alkaline, andacid phosphatase levels and an increase inPb content; protein, DNA, and lipid totalamounts were reduced, and hepatic glycogencontent was diminished at 12 and 21 PN,with a higher dose of glucose in blood; decrease in alkaline phosphatase in liver of pupsat day 21 PN, but acid phosphatase was unaltered.PbB 22 μg/dLCorpas et al.(2002b)Rat/Wistar,adult300 mg/L acetate Pb indrinking water beginning atmating until PND 12 and 21Neither abnormalities in the liver structure nor depositions of Pb, toxicant producedbiochemical alterations; pups exhibited decrease in hemoglobin, iron and alkaline, andacid phosphatase levels and an increase inPb content; protein, DNA, and lipid totalamounts were reduced, and hepatic glycogencontent was diminished at 12 and 21 PN,with a higher dose of glucose in blood; decrease in alkaline phosphatase in liver of pupsat day 21 PN, but acid phosphatase was unaltered.PbB 22 μg/dL

# AX5-47Table AX5-4.2 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on MalesCitationSpecies/Strain/Age Dose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Cory-Slechtaet al. (2004)†Rat/Long-Evans,adultPb acetate in drinking waterbeginning 2 mo beforebreeding until the end oflactationObserved potential effects of Pb and stress infemale; Pb alone (in male) and Pb plusstress (in females) permanently elevatedcorticosterene levels in offspring.PbB 30–40 μg/dLFoote (1999) Rabbit/Dutch-belted, adult0, 0.005, 0.01, and 0.025 mMPbCl2 in vitro; one time doseSix out of 22 males tested showed appreciablespontaneous hyperactivation, Pb did notaffect hyperactivation, orassociated capacitation.PbB not applicable–in vitro studyFoster et al.(1993)Monkey/Cynomolgus,adult0–1500μg Pb acetate/kg-d ingelatin capsules p.o. forvarious durations: 9 controlmonkeys, 4 monkeys inlifetime group (birth to 9 yrs),4 in infancy group (first400 days of life), 4 in post-infancy exposure (from300 days to 9 yrs)Suppressed LH response to GnRH stimulation in the lifetime group (p = 0.0370);Sertoli cell function (reduction in the inhibin toFSH ratio) (p = 0.0286) in lifetime andpost-infancy groups.Lifetime group 3–26 μg/dL at4–5 yrs; infancy group5–36 μg/dL at 100–300 days,3–3 μg/dL at 4–5 yrs; postinfancy group 20–35 μg/dLFoster et al.(1996a)Monkey/Cynomolgus,adult0–1500μg Pb acetate/kg-d ingelatin capsules p.o. frombirth until 9 yrs of age:8 control monkeys, 4monkeys in low group(6-20 μg/dL), 7 monkeys inhigh group (22–148 μg/dL)Mean PbB of 56 μg/dL showed no significant alterations in parameters of semenquality (count, viability, motility, or morphology).PbB 10 ± 3 or 56 ± 49 μg/dLFoster et al.(1998)Monkey/Cynomolgus,adult0–1500μg Pb acetate/kg-d ingelatin capsules p.o. forvarious durations: birth to10 yrs (lifetime); PND 300 to10 yrs (post-infancy); birth to300 days (infancy); 3 controlmonkeys, 4 lifetime,4 infancy, 5 post-infancyCirculating concentrations of FSH, LH, and testosterone were not altered by treatment;semen characteristics (count, motility, morphology) were not affected by treatmentpossibly because not all Sertoli cells were injured; degeneration of seminiferousepithelium in infancy and lifetime groups(no difference in severity between thesegroups); ultrastructural alterations in seminal vesicles, most prominent in infancy andpost-infancy groups.PbB ~35 μg/dLGandley et al.(1999)Rat/SpragueDawley, adultMale rats received Pb acetate25 or 250 ppm in drinkingwater for 35 days prior tomatingHigh dose reduced fertility; low dose altered genomic expression in offspring.PbB 15–23 μg/dL or27–60 μg/dLGorbel et al.(2002)Rat/(NOS),90 days old3 mg (P1) or 6 mg (P2) Pbacetate in drinking water for15, 30, 45, 60, or 90 daysMale rats, absolute and relative weights oftestis, epididymis, prostate and seminalvesicles were found to significantly decreaseat day 15 in P2 group and at day 45 in P1group, at day 60 these absolute values and relative weights returned to control values; atday 15 arrest of cell germ maturation, changes in the Sertoli cells, and presence ofapoptotic cells were observed; serum testosterone level was found to be lowered at day15 in both P1 and P2, and peaked at day 60, then returned to normal values.PbB not reported

# AX5-48Table AX5-4.2 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on MalesCitationSpecies/Strain/Age Dose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Graca et al.(2004)Mouse/CD-1,2 mo oldSubcutaneous injection of74 mg/kg-d of Pb chloride for1 to 3 daysReversible changes in sperm (count) and ultrastructural changes in testes (reduceddiameter of seminiferous tubules).PbB not reportedHsu et al.(1997)Rat/Sprague-Dawley, 7 wksold10 mg/kg Pb acetate throughi.p. injection to males for 6 or9 wksSix-week group had unchanged epididymal sperm counts, percent of motile sperms, andmotile epididymal sperm counts comparedwith control group; 9-wk group showedstatistically lower epididymal sperm counts,and lower motile epididymal sperm counts;good correlation between blood Pb and sperm Pb; significantly higher counts ofchemiluminescence, they were positively associated with sperm Pb level; epididymalsperm counts, motility, and motile epididymalsperm counts were negatively associatedwith sperm chemiluminescence; SOPR were positively associated with epididymalsperm counts, motility and motile epididymal sperm counts, sperm chemiluminescencewas negatively associated with SOPR.PbB after 6 wks 32 μg/dL, after9 wks 48 ± 4.3 μg/dLHsu et al.(1998a)Rat/Sprague-Dawley,100–120 g20 or 50 mg Pb acetate viai.p. route weekly to males for6 wksSerum testosterone levels were reduced; percentage of capacitation and thechemiluminescence were significantly increased in fresh cauda epididymalspermatozoa; serum testosterone levels werenegatively associated with the percentageof acrosome-reacted spermatozoa; spermchemiluminescence was positively correlatedwith the percentage of both capacitated and acrosome-reacted spermatozoa; SOPR wasnegatively associated with the percentageof both capacitated and acrosome-reactedspermatozoa.PbBs >40 μg/dLHsu et al.(1998b)Rat/Sprague-Dawley, 7 wksold10 mg/kg Pb acetate weeklyvia i.p. injection to males for6 wksIntake of VE and/or VC in Pb exposed rats prevented the Pb associated sperm ROSgeneration, increased the epididymal spermmotility, enhanced the capacity of sperm topenetrate eggs harvested from unexposed femalerats in vitro; protective effect of VEand VC not associated with reduced blood or sperm Pb levels.PbB 30.1 ± 3.4 to 36.1 ± 4.6PbBs >40 μg/dLHuang et al.(2002)Mouse MA-10cells10−8to 10−5M Pb incubatedfor 3 hrHigher decreases in human chorionic gonadotropin (hCG)-stimulated progesteroneproduction, expressions of StAR protein, and the activity of 3ß-HSD compared to 2 hr;no affect on P450scc enzyme activity.PbB not applicable–in vitro studyJohansson(1989)Mouse, 9 wksold0–1 g Pb chloride/L indrinking water for 112 daysNo effects on frequency of motile spermatozoa, nor on swimming speed; decreasedfertilizing capacity of the spermatozoa by in vitro fertilization; premature acrosomereaction .PbB 0.5–40 μg/dLJohansson andPellicciari(1988)Mouse/NMRI,9 wks old1 g/L Pb chloride in drinkingwater for 16 wksDecreased uptake of PI was found in spermatozoa from the vas deferens of the Pb-exposed mice; after thermal denaturation ofthe DNA, the spermatozoa showed a higheruptake of PI in comparison to those of the controls; after reductive cleavage of S-Sbonds with DTT and staining with a thiol-specific reagent significantly fewer reactivedisulfide bonds were also observed in the spermatozoa; significant delay in the capacityfor NCD was noted.PbB 42 ± 1.6 μg/dLJohansson andWide (1986)Mouse/NMRI,9 wks old0–1 g/L Pb chloride indrinking water for 84 daysNo effects on sperm count; no effects on serum testosterone; reduced number ofimplantations after mating.PbB <0.5–32 μg/dLMean tissue Pb contentdifference between Pb treatedand controls: testicular 11 μg/g(epididymal 67 μg/g)PbB <0.5 μg/100 mL

# AX5-49Table AX5-4.2 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on MalesCitationSpecies/Strain/Age Dose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Johanssonet al. (1987)Mouse/NMRI,9–10 wks old1 g/L Pb chloride in drinkingwater for 16 wksSpermatozoa had significantlylower ability to fertilize mouse eggs; morphologicallyabnormal embryos were found.PbB not reportedKempinaset al. (1988)Rat/Wistar,adult0.5 g/L and 1.0 g/L Pb acetatein drinking water for 90 daysPbB exhibited a significant increase in both groups; decrease in hematocrit andhemoglobin, together with a rise in glucose levels; no signs of lesion were detectedupon histological examination of testes, caput, and cauda epididymidis; an increase inductal diameter, and a decrease in epithelial height were observed in the caudaepididymidis; concentration of spermatozoa stored in the caudal region of theepididymis exhibited a significantincrease in Pb-treated animals.PbB 65–103 μg/dL(1.0 g/L) Pb acetate indrinking water in addition toi.v. injections of Pb acetate(0.1 mg/100 g bw) every10 days, 20 daysKempinaset al. (1990)Rat/NOS,pubertal(1.0 g/L) Pb acetate indrinking water in addition toi.v. injections of Pb acetate(0.1 mg/100 g bw) every15 days, 9 moBasal levels of testosteronewere higher both in the plasma and in the testes of acutelyintoxicated animals; levels of LH were not affected in either group, nor was the LHRHcontent of the median eminence; densityof LH/hCG binding sites in testicularhomogenates was reduced by saturnism in bothgroups, apparent affinity constant of thehormone-receptor, complex significantly increased.PbB ~40 μg/dL0–1 g Pb acetate/L indrinking water + 0.1 mg/kgi.v. every 10 days for 20 daysPbB 10–41 μg/dLKempinaset al. (1994)Rat/Wistar,50 days old0–1 g Pb acetate/L indrinking water + 0.1 μg/kgi.v. every 15 days for270 daysIncreased plasma and testicular testosterone concentrations; no effects on testicularweight; reduced weight of prostate; increased weight of seminal vesicle and seminalsecretions.PbB 8.5–40 μg/dLKlein et al.(1994)Rat/Sprague-Dawley,100 days old0.1, 0.3, or 0.6% Pb acetate indistilled water for 21 days2–3-fold enhancement of mRNA levels ofGnRH and the tropic hormone LH; 3-foldenhancement of intracellular stores of LH; mRNA levels of LH and GnRH and pituitarylevels of stored LH are proportional to blood levels of Pb.PbB 42–102 μg/dLLiu et al.(2001)Mouse,MA-10 cells10−8to 10−5Pb acetate invitro for 2 hrSignificantly inhibited hCG- and dbcAMP-stimulated progesterone production inMA-10 cells; steroid production stimulated byhCG or dbcAMP were reduced by Pb;expression of StAR protein and the activities of P450 side-chain cleavage (P450) and3ß-HSD enzymes detected; expression of StAR protein stimulated by bdcAMP wassuppressed by Pb at about 50%; progesterone productions treated with 22Rhydroxycholesterol or pregnenolone were reduced 30–40% in Pb treated MA-10 cells.PbB not applicable–in vitro studyLiu et al.(2003)Mouse,MA-10 cells10−8to 10−5Pb acetate invitro for 6 hr incubatedPb significantly inhibited hCG- and dbcAMP-stimulated progesterone production from20 to 35% in MA-10 cells at 6 hr; Pb suppressed the expression of steriodogenesis acuteregulatory (StAR) proteinfrom 30 to 55%; activities P450 side-chain cleavage(P450scc) enzyme and 3ß-HSD were reduced by Pb from 15 to 25%.PbB not applicable–in vitro study

# AX5-50Table AX5-4.2 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on MalesCitationSpecies/Strain/Age Dose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Marchlewiczet al. (1993)Rat/Wistar,90 days old0–1% Pb acetate in drinkingwater for 270 daysNo histological or weight changes in testicle or epididymis; fever spermatozoa in allzones of the epididymis.PbB not reportedMcGivernet al. (1991)†Rat/Sprague-Dawley, adult0.1% Pb acetate in drinkingwater from GD 14 toparturition: 8 control litters;6 Pb acetate litters (5 malesper litter)Decreased sperm count (21% at 70 days and 24% at 165 days; p < 0.05); reduced malebehavior (p < 0.05); enlarged prostate (25% increase in weight; p < 0.07); irregularrelease patterns of both FSH and LH (p < 0.05).Control PbB <5 μg/dL at birthMaternal PbB 73 μg/dL at birthPup PbB 64 μg/dL at birthMcMurryet al. (1995)Rat/Cotton,adult0, 100, or 1000 ppm Pb indrinking water for 7 or13 wksImmune function was sensitive to Pb exposure;spleen mass was reduced in cotton ratsreceiving 100 ppm Pb; total leukocytes, lymphocytes, neutrophils, eosinophils, totalsplenocyte yield, packed cell volume, hemoglobin, and mean corpuscular hemoglobinwere sensitive to Pb exposure; reduced massof liver, seminal vesicles, and epididymisin males after 7 wk exposure.PbB not reportedMishra andAcharya(2004)Mouse/Swiss,9–10 wks old10 mg/kg Pb acetate indrinking water for 5 to 8 wksStimulates lipid peroxidation in the testicular tissue, associated with increasedgeneration of noxious ROS; reduced sperm count, increased sperm abnormalityPbB not reportedMoormanet al. (1998)Rabbit/NOS,adult3.85 mg/kg Pb acetatesubcutaneous injection for15 wksIncreased blood levels associated with adverse changes in the sperm count, ejaculatevolume, percent motile sperm, swimming velocities, and morphology; hormonalresponses were minimal; dose-dependent inhibition of sperm formation; semen quality,threshold estimates ranged from 16 to 24 μg/dL.PbB 0, 20, 40, 50, 70, 80, 90, and110 μg/dLMurthy et al.(1991)Rat/ITRC,(NOS),weanling0–250 ppm Pb acetate indrinking water for 70 daysAt 20 μg/dL no impairment of spermatogenesis; vacuolization of Sertoli cell cytoplasmand increase in number and size of lysosomes.PbB 20.34 ± 1.79 μg/dLMurthy et al.(1995)Rat/Druckrey,adultPb 5 mg/kg i.p. Pb acetate indrinking water for 16 daysSwelling of nuclei and acrosomes round spermatids; in Sertoli cells, nuclei appearedfragmented, whereas the cytoplasm exhibited a vacuolated appearance and a fewstructures delimitated by a double membranethat contains microtubules arranged inparallel and cross-striated fin fibrils, celltight junction remain intact; no significantchange in epididymal sperm motility and counts, testicular blood levels were found tobe elevated after Pb exposure.PbB 7.39 μg/dLNathan et al.(1992)Rat/Sprague-Dawley, adult0, 0.05, 0.1, 0.5, or 1% Pbacetate in drinking water for70 daysNo effects on spermatogenesis in all groups; at 124 μg/dL: decreased seminal vesicleweight; decreased serum testosterone in the 0.5% group at 10 wks; no effects in theother exposure categories; no effects on serum FSH, LH, nor pituitary LH content.PbB 2.3, 40, 44, 80, or 124 μg/dLPace et al.(2005)Mouse/BALB/c,adult0.1 ppm Pb acetate indrinking water (lactationalexposure as neonates anddrinking water from PND 21to PND 42)Reduction in fertility when mated with unexposed females; no change in sperm count;increase in number of apoptotic cells in testes.Neonatal PbB 59.5 μg/dLPost PND 21 PbB 20.3 μg/dLPiasecka et al.(1995)Rat/Wistar,adult1% aqueous solution of Pbacetate for 9 moPb-loaded (electron dense) inclusions werefound in the cytoplasm of the epididymalprincipal cells, especially in the caput ofepididymis, also present, but smaller, insmooth muscle cells; inclusions were located in the vacuoles, rarely without anysurrounding membrane; similar Pb-containing structures were found in the epididymallumen.PbB not reported

# AX5-51Table AX5-4.2 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on MalesCitationSpecies/Strain/Age Dose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Piasek andKostial (1987)Rat/Albino,(NOS), adult1500, 3500, and 5500 ppm ofPb acetate in drinking waterfor 18 wksNo overt signs of general toxicity in adultfemale rats, only at the end of the exposureperiod the mean body weight of males exposedto two higher levels was slightly lower;no effect of Pb exposure on male fertility either after first or after second mating; valuesin the pups did not differ from control group.PbB not reported0–0.3% Pb acetate indrinking water for 70 daysPinon-Latailladeet al. (1993)Rat/Sprague-Dawley,90 days old5 mg/m2Pb oxide in aerosolfor 6 hr/day, 5 days/wk,90 daysDecreased weight of seminal vesicles in inhalation study; no effects on spermatogenesis(epididymal sperm count, spermatozoal motility or morphology) or plasma testosterone,LH, and FSH; no effects on fertility; decrease inepididymal sperm count of progeny ofsires of the inhalation group, howeverwithout effect on their fertility.PbB 58 ± 1.7 μg/dL (oral)PbB 51.1 ± 1.8 μg/dL(inhalation)Pinon-Latailladeet al. (1995)Mouse/NMRI,adult0–0.5% Pb acetate indrinking water, day 1 ofgestation until 60 days of ageNo effects on testicular histology, noron number and morphology of epididymalspermatozoa; no effects on plasma FSH,LH, and testosterone, nor on testiculartestosterone; decreased weight of testes,epididymis, seminal vesicles, and ventralprostate; no effects on fertility.PbB <4–132 μg/dLRodamilanset al. (1988)Mouse/BALB/c,63 days old0–366 mg Pb acetate/L indrinking water for 30, 60, 90,120, 150, 180 daysReduction of intratesticular testosterone concentrations after 30 days; reduction of andrenostenedione concentrations after 150 days;no changes in intratesticular progesteroneand hydroxy-progesterone.PbB 48–67 μg/dLRonis et al.(1996)†Rat/Sprague-Dawley, adult0.6% Pb acetate in drinkingwater for various durations:PND 24–74 (pubertalexposure); PND 60–74 (postpubertal exposure); 11 malesand females in pubertalexposure group (10 each incontrol pubertal group);6 males and females post-pubertal exposure and controlgroupsPbB > 250 μg/dL reduced circulating testosterone levels in male rats 40–50%(p < 0.05); reduction in male secondary sex organ weight (p < 0.005); delayed vaginalopening (p < 0.0001); disrupted estrous cycle in females (50% of rats); increasedincidence of stillbirth (2% control vs. 19% Pb) (p < 0.005).Pubertal PbB 30–60 μg/dLPost pubertal PbB 30–60 μg/dLMean PbBs in male rats 30–60 μg/dL, respectivelyRonis et al.(1998a)Rat/Sprague-Dawley, adult0.6% Pb acetate in drinkingwater ad libitum for variousdurations as follows: GD 5 toPND 1; GD 5 to weaning;PND 1 to weaning; 3 controllitters, 2 gestation exposurelitters, 2 lactation exposurelitters, 2 gestation andlactation exposure litters,2 postnatal exposure litters,2 chronic exposure litters;4 male and 4 female pupsper litter.Suppression of adult mean serum testosterone levels was only observed in male pupsexposed to Pb continuously from GD 5 throughout life (p < 0.05).Group: male PbBNaïve: 5.5 ± 2.0 μg/dLControl: 1.9 ± 0.2 μg/dLGest: 9.1 ± 0.7 μg/dLLact: 3.3 ± 0.4 μg/dLGest+Lact: 16.1 ± 2.3 μg/dLPostnatal: 226.0 ± 29 μg/dLChronic: 316.0 ± 53 μg/dL

# AX5-52Table AX5-4.2 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on MalesCitation Species/ Strain/Age Dose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Ronis et al.(1998b)Rat/Sprague-Dawley, adultPb acetate in drinking water(0.05% to 0.45% w/v); damsexposed until weaning,exposure of pups whichcontinued until PND 21, 35,55, or 85; 5 control litters(0%), 10 low-dose litters(0.05%), 8 mid-dose litters(0.15%), 9 high-dose litters(0.45%); 4 male and 4 femalepups per litterDose-response reduction in birth weight(p < 0.05), more pronounced in male pups;decreased growth rates in both sexes (p < 0.05) were accompanied by a statisticallysignificant decrease in plasma concentrations of IGF1 through puberty PND 35 and55 (p < 0.05); increase in pituitary growth hormone during puberty (p < 0.05).Mean PbB in offspring at 0.05%(w/v) 49 ± 6 μg/dLMean PbB in offspring at 0.15%(w/v) 126 ± 16 μg/dLMean PbB in offspring at 0.45%(w/v) 263 ± 28 μg/dLRonis et al.(1998c)†Rat/Sprague-Dawley, adultPb acetate 0.05, 0.15, or0.45% in drinking waterbeginning GD 5 continuinguntil PND 21, 35, 55, or 85;5 control litters (0%), 10 low-dose litters (0.05%), 8 mid-dose litters (0.15%), 9 high-dose litters (0.45%); 4 maleand 4 female pups per litterDose-responsive decrease in birth weight (p < 0.05); dose-responsive decrease incrown-to-rump length (p < 0.05); dose-dependent delay in sexual maturity (p < 0.05);decrease in prostate weight (p < 0.05); decrease in plasma concentration oftestosterone during puberty (p < 0.05); decrease in plasma LH (p < 0.05); elevatedpituitary LH content (p < 0.05); decrease inplasma testosterone/LH ratio at high dose(p < 0.05).Dams: 0, 48, 88, or 181 μg/dLPups PND 1: <1, 40, 83, or120 μg/dLPups PND 21: <1, 46, 196, or236 μg/dLPups PND 35: <1, 20, 70, or278 μg/dLPups PND 55: <1, 68, 137, or379 μg/dLPups PND 85: <1, 59, 129, or214 μg/dLSant'Anaet al. (2001)Rat/Wistar, 90 daysold0.1 and 1% Pb acetate indrinking water for 7 days0.1% Pb caused decrease in testis weight,an increase in seminal vesicle weight andno changes in plasma testosterone levels, hypothalamic VMA levels were increasedcompared to control group.PbB 36.12 ± 9.49 μg/dL and13.08 ± 9.42 μg/dLSaxena et al.(1984)Rat/ITRC, albino(NOS), 12 wks old8 mg/kg Pb acetate i.p. for15 daysHistoenzymic and histologicalalterations in the testes; degeneration of seminiferoustubules; patchy areas showing marked lossin the activity of succinic dehydrogenaseand adenosine triphosphatase, whereas alkaline phosphatase activity showed onlyslight inhibition.PbB not reportedSaxena et al.(1986)Rat/ITRC, albino(NOS), 40–50 g5, 8, or 12 mg Pb+2/kg Pbacetate i.p. for 15 daysIncreasing dose of Pb resulted in significant loss of body weight, as well as testicularweight in groups 3 and 4; cholesterol in the testis of rats markedly decreased at allgiven doses of Pb and was statistically significant in groups 3 and 4; in phospholipidcontents, the significant decrease was observed only at two highest doses, while at thelowest dose the decrease was not significant;activity of ATPase remained unaffectedat all three doses of Pb; no significant increase in Pb content in the testis was noticedat lower dose levels as compared to control; however, significant increase was foundin groups 3 and 4 which was dose dependent.PbB not reportedSaxena et al.(1987)Rat/Wistar, 40–50 g8 mg Pb2/kg-d Pb acetate i.p.for 100 days (from PND 21 toPND 120)Disturbed spermatogenesis; Leydig celldegeneration; altered enzyme activity(G6PDH).PbB not reported

# AX5-53Table AX5-4.2 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on MalesCitation Species/Strain/Age Dose/Route/ Form/Duration EndpointBlood Lead Concentration(PbB)Saxena et al.(1990)ITRC albino,(NOS), adult8 mg/kg/d Pb acetate for45 daysAlterations in SDH, G6PDH activity, cholesterol, and ascorbic acid contents andreduced sperm counts associated with marked pathological changes in the testis,after combined treatment with Pb and immobilization stress in comparison to eitheralone.PbB >200 μg/dLMonkey/Cynomolgus, birthBirth:Singh et al.(1993a)300 days:0–1500μg Pb acetate/kg-d ingelatin capsules for variousdurations: 3 controlmonkeys, 4 monkeys ininfancy group (exposure first400 days), 5 in post-infancygroup (exposure 300 days to9 yrs of age), 4 in lifetimegroup (exposure from birthuntil 9 yrs)Degeneration of seminiferous epithelium in all exposed groups (frequency notspecified); ultrastructural alterations in seminal vesicles, most prominent in infancyand post-infancy groups (frequency not specified).Chronic PbB <40–50 μg/dLSokol (1987) Rat/Wistar, 52 daysold0–0.3% Pb acetate indrinking water for 30 daysHyper-responsiveness to stimulation with both GnRH and LH (10); bluntedresponse to naloxone stimulation (10).PbB 30 ± 5 μg/dLRat/Wistar, 27 daysold0–0.6% Pb acetate indrinking water for 30 days +30 days recovery<3–43 μg/dL (<4–18 μg/dL afterrecovery period)Sokol (1989)52 days old0–0.6% Pb acetate indrinking water for 30 days +30 days recoverySuppressed intratesticular sperm counts, sperm production rate, and serumtestosterone in both Pb treated groups (10–10); sperm parameters and serumtestosterone normalized at the end of the recovery period in the pre-pubertal animals(27 days at start) (10) but not in the pubertal animals (52 days at start) (5).B1 <3–43 μg/dL (<4–18 μg/dLafter recovery period)Sokol (1990) Rat/Wistar, 52 daysold0–0.6% Pb acetate indrinking water for 7, 14, 30,60 daysDecreased sperm concentration, sperm production rate and suppressed serumtestosterone concentrations after 14 days of exposure; not dose related (NS).Controls: <8 μg/dL at any timeexposed: 42, 60, 58, 75 μg/dLafter 7, 14, 30, and 60 days,respectively0% All <7 μg/dL42 days 25 μg/dL52 days 35 μg/dL0.1%70 days 37 μg/dL42 days 36 μg/dL52 days 60 μg/dLSokol andBerman(1991)Rat/Wistar, NOS 0, 0.1, or 0.3% Pb acetate indrinking water for 30 daysbeginning at 42, 52, or70 days old; 8–11 control ratsfor each age, 8–11 rats foreach age in 0.1% group, 8–11 rats for each age in 0.3%groupDose-related suppression of spermatogenesis (decreased sperm count and spermproduction rate) in the exposed rats of the two highest age groups (p < 0.05); doserelated suppression of serum testosterone in52-day old rats (p = 0.04) and in 70-dayold rats (p < 0.003).0.3%70 days 42 μg/dL

# AX5-54Table AX5-4.2 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on MalesCitationSpecies/Strain/Age Dose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Sokol et al.(1985)†Rat/Wistar,52 days old0.1 or 0.3% Pb acetate indrinking water for 30 daysNegative correlations between PbB levels and serum and intratesticular testosteronevalues; dose-dependent reduction in intratesticular sperm count; FSH values weresuppressed; no change in LH; decrease inventral prostatic weight; no difference intesticular or seminal vesicle weights.PbB 34 ± 3 μg/dL orPbB 60 ± 4 μg/dLSokol et al.(1994)Rat/Sprague-Dawley,100 days old0.3% Pb acetate in drinkingwater for 14, 30, or 60 daysPb exposed fertilized fewer eggs; increased duration of exposure did not result in moresignificant percentage of eggs not fertilized; no ultrastructural changes were noted inthe spermatozoa of animals; no difference inhistogram patterns of testicular cells.PbB ~40 μg/dLSokol et al.(2002)Rat/Sprague-Dawley, adultPb acetate in water for 1 wk Dose-related increase ingonadotropin-releasing hormone(GnRH) mRNA; no effecton the serum concentrations of hypothalamic gonadotropin-releasing hormone (GnRH)or LH.PbB 12–28 μg/dLThoreux-Manlay et al.(1995a)Rat/Sprague-Dawley, 97 daysold0–8 mg Pb acetate/kg i.p. for5 days/wk, 35 daysNo effects on spermatogenesis; decreased plasma and testicular testosterone by 80%;decreased plasma LH by 32%, indications forimpaired Leydig cell function, no effectson fertility.PbB not reportedThoreux-Manlay et al.(1995b)Rat/Sprague-Dawley, adult8 mg/kg-d Pb for 5 days/wk,35 daysGerm cells and Sertoli cells were not major target of Pb, accessory sex glands weretarget; epididymal function was unchanged; plasma and testicular testosterone droppedabout 80%, plasma LH only dropped 32%.PbB 1700 μg/dLWadi andAhmad (1999)Mouse/CF-1,adult0.25 and 0.5% Pb acetate indrinking water for 6 wksLow dose significantly reduced number of sperm within epididymis; high dose reducedboth the sperm count and percentage of motilesperm and increasedthe percentage ofabnormal sperm within the epididymis; no significant effect on testis weight, high dosesignificantly decreased the epididymis and seminal vesicles weights as well as overallbody weight gain; LH, FSH, and testosterone were not affected.PbB not reportedWenda-Rózewickaet al. (1996)Rat/Wistar,adult1% aqueous solution of Pbacetate for 9 moElectron microscopic studies did not reveal any ultrastructural changes in thesemiferous epithelium or inSertoli cells; macrophages of testicular interstitial tissuecontained (electron dense) Pb-loaded inclusions, usually located inside phagolisosome-like vacuoles; x-ray micro-analysis revealed that the inclusions contained Pb.PbB not reportedYu et al.(1996)Rat/Sprague-Dawley,neonatesNeonatal and lactationalexposure to 0.3% Pb acetatein drinking water beginningPND 1 to PND 21Neonatal exposure to Pb decreased cold-waterswimming endurance (a standard test forstress endurance) and delayed onset of puberty in males and female offspring, whichwas exacerbated by swimming stress.PbB 70 μg/dL*Not including effects on the nervous or immune systems.†Candidate key study.3ß-HSD, 3ß-hydroxysteriod dehydrogenase; dbcAMP, dibutyryl cyclic adenosine-3',5'-monophosphate; DTT, dithiothreitol; FSH, follicle stimulating hormone;G6PDH, glucose-6-phosphatedehydrogenase; GD, gestational day;GnRH, gonadotropin releasing hormone; hCG, human chorionic gonadotropin; IGF1, insulin-like growth factor 1; i.p., intraperitoneal; LDH, lactatedehydrogenase; LH, luteinizing hormone; LHRH, luteinizing hormone releasing hormone; LPP, lipid peroxidation potential; NCD, nuclear chromatin decondensation rate; NOS, not otherwisespecified; PbB, blood lead concentration; PND, post-natal day;p.o., per os (oral administration); ROS, reactive oxygen species; SDH, succinic acid dehydrogenase; SOPR, sperm-oocyte penetrationrate; StAR, steroidogenic acute regulatory protein; VC,vitamin C; VE, vitamin E;VMA, vanilmandelic acid

# AX5-55Table AX5-4.3. Effect of Lead onReproduction and Development in Mammals Effects on FemalesCitationSpecies/Strain/AgeDose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Burright et al.(1989)Mouse/HET,neonates0.5% Pb acetate solution viamilk, or drinking waterchronic beginning PND 1Plasma prolactin levels implied that Pb exposure alone decreased circulating prolactinin primiparous; low prolactin levels in non-behaviorally tested females suggests thatdietary Pb alone may alter plasma-hormone in these lactating HET dams; pattern ofplasma prolactin appear to be inconsistent with the observation that Pb exposuredecreases dopamine; prolactin levels ofPb exposed dams were very low.PbB ~100 μg/dLCoffigny et al.(1994)†Rat/Sprague-Dawley, adultInhalation exposure to5 mg/m3Pb oxide daily for13 days during gestation(GD 2, 3, 6–10, 13–17, 20)No effects on the incidence of pregnancy, prenatal death, or malformations when maleand female rats from mothers who had been exposed.PbB 71.1 μg/dL (dam)PbB 83.2 μg/dL (fetal)Corpas et al.(2002a)Rat/Wistar,adult300 mg/L acetate Pb indrinking water from matinguntil PND 12 or PND 21Neither abnormalities in the liver structure nor depositions of Pb, toxicant producedbiochemical alterations; pups exhibited decrease in hemoglobin, iron and alkaline, andacid phosphatase levels and an increase inPb content; protein, DNA, and lipid totalamounts were reduced, and hepatic glycogencontent was diminished at 12 and 21 PN,with a higher dose of glucose in blood; decrease in alkaline phosphatase in liver of pupsat day 21 PN, but acid phosphatase was unaltered.PbB 22 μg/dLCory-Slechtaet al. (2004)†Rat/Long-Evans,adultPb acetate in drinking waterbeginning 2 mo beforebreeding through weaningObserved potential effects of Pb and stress infemale; Pb alone (in male) and Pb plusstress (in females) permanently elevatedcorticosterene levels in offspring.PbB 30–40 μg/dLDearth et al.(2002)†Rat/Fisher 344,150–175 g12 mg/mL Pb acetate gavagefrom 30 days prior breedinguntil pups were weaned21 days after birth; 10–32 litters per group, controlgroup, gestation and lactationexposure, gestation onlyexposure, lactation onlyexposureDelay in onset of puberty (p < 0.05); reduced serum levels of IGF1 (p < 0.001), LH(p < 0.001), and E2 (p < 0.001).Maternal PbB: ~40 μg/dLPups PbB as follows:Gest+lact: ~38 μg/dL PND 10Gest+lact: ~15 μg/dL PND 21Gest+lact: ~3 μg/dL PND 30Gest: ~14 μg/dL PND 10Gest: ~3 μg/dL PND 21Gest: ~1 μg/dL PND 30Lact: ~28 μg/dL PND 10Lact: ~15 μg/dL PND 21Lact: ~3 μg/dL PND 30Dearth et al.(2004)Rat/Sprague-Dawley andFisher-344,adult12 mg/mL Pb acetate bygavage 30 days prior tobreeding through PND 21(gestation and lactationexposure)Pb delayed the timing of puberty in PbB 37.3 μg/dL Pb group and suppressed serumlevels of LH and E2, these effects did notoccur in PbB 29.9 μg/dL Pb group, whendoubling dose to 29.9 μg/dL group the PbB levels rose to 62.6 μg/dL, yet no effect wasnoted; results indicate that offspring are more sensitive to maternal Pb exposure withregard to puberty related insults than are 29.9 μg/dL rats.PbB 29.9 μg/dL (Sprague-Dawley)PbB 37.3 μg/dL (Fisher)

# AX5-56Table AX5-4.3 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on FemalesCitationSpecies/Strain/AgeDose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Foster (1992) Monkey/Cynomolgus,0–10 yrs oldDaily dosing for up to 10 yrswith gelatin capsulescontaining Pb acetate(1.5 mg/kg); 8 control groupmonkeys, 8 lifetime exposure(birth–10 yrs), 8 childhoodexposure (birth–400 days),and 8 adolescent exposure(postnatal day 300–10 yrs ofage)Statistically significant reductions in circulating levels of LH (p < 0.042), FSH(p < 0.041), and E2 (p < 0.0001) during menstrual cycle; progesterone concentrationswere unchanged and menstrual cycle was not significantly affected.PbB <40 μg/dLFoster et al.(1992)Monkey/Cynomolgus,10 yrs oldDaily dosing for up to 10 yrswith gelatin capsulescontaining Pb acetate(1.5 mg/kg); 8 control groupmonkeys, 8 childhood (birth–400 days), 7 adolescent(postnatal day 300–10 yrs),7 lifetime (birth–10 yrs)No effect on endometrial response to gonadal steroids as determined by ultrasound. PbB <40 μg/dLFoster et al.(1996b)Monkey/Cynomolgus,15–20 yrs oldChronic exposure to Pbacetate 50 to 2000 μg/kg-dp.o. beginning at birth for15–20 yrs; 20 controlmonkeys, 4 monkeys in50 μg/kg-d group, 3 monkeysin 100 μg/kg-d, 2 monkeys in500 μg/kg-d group, and3 monkeys in 2000 μg/kg-dgroupReduced corpora luteal production of progesterone (p = 0.04), without alterations in E2,20alpha-hydroxyprogesterone, or menstrual cyclicity.PbB 10–15 μg/dL in low group(50 or 100 μg/kg-d)PbB 25–30 μg/dL in moderategroup (500 or 2000 μg/kg-d)Franks et al.(1989)Monkey/Rhesus,adultPb acetate in drinking water(2–8 mg/kg-d) for 33 mo; 7control and 10 Pb monkeysReduced circulating concentration of progesterone (p < 0.05); treatment with Pb did notprevent ovulation, but produced longer and more variable menstrual cycles and shortermenstrual flow.PbB 68.9 ± 6.54 μg/dLFuentes et al.(1996)Mouse/Swiss,adult14, 28, 56, and 112 mg/kg Pbacetate via i.p; one timeexposure on GD 9Absolute placental weight at 112 mg/kg andrelative placental weight at 14, 56, and112 mg/kg were diminished significantly; mostsections of placenta showed vascularcongestion, and increase of intracellular spaces, and deposits of hyaline material ofperivascular predominance; trophoblast hyperplasia was also observed, whereas therewas a reinforcement of the fibrovascular network in the labyrinthPbB not reportedGorbel et al.(2002)Rat/NOS,3 mo old3 mg (P1) or 6 mg (P2) Pbacetate in drinking water for15, 30, 45, 60, or 90 daysFemale rats absolute and relative weights ofovary and uterus were unchanged, vaginalsmears practiced in females revealed the estrus phase; fertility was found to be reduced;Pb level in blood was poorly correlated with the level of poisoning.PbB not reported

# AX5-57Table AX5-4.3 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on FemalesCitationSpecies/Strain/AgeDose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Iavicoli et al.(2004)Mouse/Swiss,33–37 days old0.02, 0.06, 0.11, 0.20, 2.00,4.00, 20.00, 40.00 ppm infood Pb acetate concentrationbeginning GD 1 to 3 mo afterbirthIncrease in food consumption; however, did low-dose group increase food consumptionbecause of sweet nature of Pb. Body weight may contribute to delay in onset of pubertyand confound results.PbB 0.69, 1.32, 1.58, 1.94, 3.46,3.80, 8.35, 13.20 μg/dLJunaid et al.(1997)Mouse/Swiss,adult0, 2, 4, or 8 mg/kg-d Pbacetate, subchronic exposure,5 days/wk, 60 daysAltered follicular development.PbB 22.3–56.5 μg/dLLaughlin et al.(1987)Monkey/Rhesus,adultPb acetate in drinking waterat 3.6, 5.9, or 8.1 mg/kg-d for1–2 yrs; 7 control and 10experimental monkeys pergroupReductions in cycle frequency (p < 0.01); fewer days of flow (p < 0.01); longer andmore variable cycle intervals (p < 0.025).PbB 44–89 μg/dL51.2 μg/dL (low dose)80.7 μg/dL (mid dose)88.4 μg/dL (high dose)Lögdberget al. (1987)Monkey/Squirrel, adultPb acetate in drinking waterfrom 9th week of gestation toPND 1; per oral exposuresimilar to Laughlin et al.(1987)Increase in pre- and perinatal mortality during the last two-thirds of pregnancy;statistically significant reduction in meanbirth weight was observed in Pb exposedmonkeys as compared to controls.Mean maternal PbB 54 μg/dL(39–82 μg/dL)Lögdberget al. (1988)Monkey/Squirrel, adultPb acetate maternal dosingfrom 5–8.5 wks pregnant toPND 111 control monkeys, 3 low-Pb exposure group (PbB24 μg/dL), 7 medium Pbgroup (PbB 40 μg/dL, 5 high-Pb group (PbB 56 μg/dL)Dose-dependent reduction in placental weight(p < 0.0007); various pathological lesionswere seen in the placentas, including hemorrhages, hyalinization of the parenchymawith destruction of the villi, and massive vacuolization of chorion epithelium.PbB 37 μg/dL (22–82 μg/dL)24 (22–26) μg/dL (low dose)40 (35–46) μg/dL (mid dose)56 (43–82) μg/dL (high dose)McGivernet al. (1991)†Rat/Sprague-Dawley, adult0.1% Pb acetate in drinkingwater from GD 14 toparturitionFemale rats showed delay in vaginal opening; 50% exhibited prolonged and irregularperiods of diestrous and lack observable corpora lutea; both sexes showed irregularrelease patterns of both FSH and LH.PbB 73 μg/dLNilsson et al.(1991)Mouse/NMRI,adult75 μg/g bw Pb chloride viai.v.; one time injection onGD 4Electron microscopy showed that the uterinelumen, which was closed in control mice,was opened in Pb-injected mice; suggested thatPb caused increase in uterine secretion;study suggested Pb could havea direct effect on the function of the uterine epitheliumand that Pb was secreted into the uterine lumen and affect the blastocysts.PbB not reportedPiasek andKostial(1991)Rat/Wistar,10 wks old7500 ppm Pb acetate indrinking water for 9 wksDecrease in litter size, pup survival, and birth weight; food consumption, body weight,and fertility were not altered in 20 wk exposure period.Maternal PbB >300 μg/dLOffspring PbB >220 μg/dLPinon-Latailladeet al. (1995)Mouse/NMRI,adult0–0.5% Pb acetate indrinking water exposed to Pbduring gestation until postGD 60Exhibited reduced fertility as evidenced by smaller litters and fewerimplantation sites. PbB 70 μg/dL

# AX5-58Table AX5-4.3 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on FemalesCitationSpecies/Strain/AgeDose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Priya et al.(2004)Rat/CharlesFoster,6–9 mo old0.03 μM Pb in vitro for 1 h LH binding was dropped to 84%in Pb treated cells; Pb exposed cells showed 31%reduction in the enzymes 17ß-HSDH and 17ß-HS; Pb can cause a reduction in LH andFSH binding, which significantly alters steroid production in vitro and exerts a directinfluence on granulose cell function.PbB not applicable–in vitro studyRonis et al.(1996)Rat/Sprague-Dawley, variousagesPb acetate in the drinkingwater or male and female ratsfor the following durations:PND 24–74 (pubertalexposure); PND 60–74(post pubertal exposure)Data suggest that both the temporary and the long-lasting effects of Pb on reproductiveendpoints in male and female experimental animals are mediated by the effects of Pb onmultiple points along the hypothalamic-pituitary-gonad axis; exposure of male andfemale Sprague-Dawley rats pre-pubertally(age 24–74 days) to Pb acetate in thedrinking water resulted in significant reductionin testis weight and in the weight ofsecondary sex organs in males; these effects were not observed in rats exposed post-pubertally (day 60–74); there is convincing evidence that pre-pubertal female ratsexposed in utero and during lactation havereduced levels of circulating E2 and LH.Maternal PbB 30–60 μg/dLOffspring PbB >200 μg/dL.Ronis et al.(1998a)†Rat/Sprague-Dawley, adult0.6% Pb acetate in drinkingwater; ad libitum for variousdurations as follows: GD 5 toPND 1, GD 5 to weaning,PND 1 to weaningFemale pups exposed to Pb from birth through adulthood or from GD 5 throughadulthood were observed to have significantly delayed vaginal opening and disruptedestrus cycling; these effects on femalereproductive physiology were not observed inanimals where Pb exposure was confined only to pregnancy or lactation.Pups continuously exposed to Pb225 to 325 μg/dLRonis et al.(1998b)Rat/Sprague-Dawley, adultAd libitum intake of Pbacetate (0.05 to 0.45% w/v);Pb exposure of dams untilweaning, exposure of pupsuntil day 21, 35, 55, 85Prenatal Pb exposure that continues untiladulthood (85 days old) delays sexualmaturation in female pups in a dose-related manner; dose-dependent delay in sexualmaturation (delayed vaginal opening) among female rats following prenatal Pbexposure that continued until adulthood (85 days old); a growth hormone-mediatedeffect on growth that differs depends upon the developmental state of the animal birthweight was significantly reduced and more pronounced among male pups; decreasedgrowth rates in both sexes were accompaniedby a statistically significant decrease inplasma concentrations of IGF1 through puberty and a significant increase in pituitarygrowth hormone during puberty; growth suppression of male and female rats involvesdisruption of growth hormone secretion during puberty.Mean PbB in offspring at 0.05%(w/v) 49 ± 6 μg/dLMean PbB in offspring at 0.15%(w/v) 126 ± 16 μg/dLMean PbB in offspring at 0.45%(w/v) 263 ± 28 μg/dLRonis et al.(1998c)Rat/Sprague-Dawley, adult0.05, 0.15, or 0.45% Pbacetate in drinking waterbeginning GD 5 for 21, 35,55, 85 daysDose-responsive decrease in birth weight and crown-to-rump length was observed inlitters; dose-dependent delay in sexual maturity (delay in vaginal opening); decrease inneonatal sex steroid levels and suppression of E2 during puberty; elevation in pituitaryLH content was observed during early puberty;E2 cycle was significantly disrupted atthe highest Pb dose; data suggests that thereproductive axis is particularly sensitive toPb during specific developmental periods, resulting in delayed sexual maturationproduced by sex steroid biosynthesis.PbB in dams 181 ± 14 μg/dLPbB in pups ranged from 197 ±82 to 263 ± 38 μg/dL, increasingwith age of pupsSierra andTiffany-Castiglioni(1992)Guineapig/NOS, adult0, 5.5, or 11 mg/kg Pbacetate, oral dose from GD 22until GD 52 or 62Hypothalamic levels of SRIF; lower serumconcentrations of progesterone at higherdose only; hypothalamic levels of GnRH and SRIF were reduced in a dose-dependentmanner by Pb treatment in both dams and fetuses; reduction of SRIF levels in 52-daysold fetus was particularly severe (92%) in the 11 mg group.PbB not reportedSrivastavaet al. (2004)Rat/Fisher 344,adult12 mg/mL Pb acetate bygavage for 30 days prior tobreeding until weaningPb decreased StAR protein expression andlowered E2 levels; suggested that theprimary action of Pb to suppress E2 is through its known action to suppress the serumlevels of LH and not due to decreased responsiveness of StAR synthesizing machinery.PbB of dams 39 ± 3.5 SEMμg/dLand offspring PbB 2.9 ±0.28 SEM μg/dL

# AX5-59Table AX5-4.3 (cont’d). Effect of Lead on Reproduction and Development in Mammals Effects on FemalesCitationSpecies/Strain/AgeDose/Route/Form/DurationEndpointBlood Lead Concentration(PbB)Taupeau et al.(2001)Mouse/C57blxCBA, 8 wks old10 mg/kg-d Pb nitrate via i.v.for 15 daysLow Pb concentration in theovary caused dysfunction offolliculogenesis, with fewerprimordial follicles and an increase in atretic antral follicles.PbB not reportedTchernitchinet al. (1998a)Rat/Sprague-Dawley, 14 daysold172 μg/g bw Pb from day 14every 2nd day until day 20Pb inhibits estrogen-induced uterine eosinophilia at 6 and 24hr after treatment; Pb alsoinhibits estrogen-induced edema in deep andsuperficial endometrial stoma at 24 hr butnot 6 hr after treatment; myometrial hypertrophy is inhibited under the effect of exposureat 24 hr of treatment.PbB 47 μg/dLTchernitchinet al. (1998b)Rat/Sprague-Dawley, 20 or21 days old(75 mg/g bw) Pb via i.v. onetime exposure at 1 or24 before hormonestimulationEnhanced some parameters of estrogen stimulation and inhibited other estrogenicresponses; interaction with responses to estrogen was different depending on whether Pbpretreatment was 1 or 24 hr before hormonestimulation; estrogenic responses mostlyaffected were uterine eosinophilia, endometrial edema, uterine liminal epithelial,hypertrophy, and mitosis in various, but not all, uterine cell types, in some cell types,estrogen-induced mitotic response developedearlier under the effect of Pb exposure.PbB not reportedWide (1985) Mouse/NMRI,10 wks old20 μg/dL/g bw Pb chloridevia i.v. single exposure ondays 8, 12, or 16 after matingLitter size and fetal survival varied significantly; small litters and increased numbers offetal deaths were observed in mice exposed toPb on day 8 of intrauterine life; live fetuseswere normal with respect to weight andmorphological appearance; ovarian folliclecounts revealed a significantly smaller numberof primordial follicles in the latter group,it suggested that the exposure to Pb at a time of early organogenesis caused the observedfertility decrease by interfering with thedevelopment of the female germ cells.PbB not reportedWide andD'Argy (1986)Mouse/NMRI,adult20 μg/g bw by i.v. singleinjection on GD 8Primordial germ cells showed a normal bodydistribution but were significantly fewer atall four stages compared with those of control embryos of corresponding age; Pb hadinterfered with the production or activity of alkaline phosphatase.PbB not reportedWiebe andBarr (1988)Rat/Sprague-Dawley, adult20 or 200 ppm Pb chloride indrinking water; 3 exposuredurations; prior to matingthrough weaning, GD 7 toweaning, PND 21 to PND 35Treatment with Pb prior to mating resulted insignificant increase in E2-receptor affinityin 21-day old offspring without a change inE2 receptor number; treatment from day 7 ofpregnancy until weaning of the pups resultedin ~35% decrease in E2 receptors per mguterine protein when these offspring reached150 days of age; Pb treatment from 21–35days old or until 150 days resulted in a significant decrease in uterine E2 receptor numberat 35 and 150 day, respectively.PbB likely 4.0 ± 1.4 to 6.6 ±2.3 μg/dL (similar design asWiebe et al. (1988)Wiebe et al.(1988)Rat/Sprague-Dawley, adult20 or 200 ppm Pb chloride indrinking water; 4 exposuredurations; prior to matingthrough weaning, GD 7 toweaning, PND 21 to PND 35,prior to mating onlyExposure to Pb did not affect tissue weights but did cause a significant decrease ingonadotropin-receptor binding in the pre-pubertal, pubertal, and adult females;conversion of progesterone toandrostenedione and dihydrotestosterone was significantlydecreased in 21-day old rats and in 150-day old females; significantly increasedconversion to the 5-alpha-reduced steroids, normally high during puberty.PbB range 4.0 ± 1.4 to 6.6 ±2.3 μg/dLYu et al.(1996)Rat/Sprague-Dawley, adultNeonatal and lactationalexposure to 0.3% Pb acetatein drinking water (PND 30)Neonatal exposure to Pb decreased cold-waterswimming endurance (a standard test forstress endurance); delayed onset of puberty inmales and female offspring, which wasexacerbated by swimming stress.PbB 70 μg/dL*Not including effects on the nervous or immune systems.†Candidate key study.E2, estradiol; FSH, follicle stimulating hormone; GD, gestational day; GnRH, gonadotropin releasing hormone; HET, Binghamton Heterogeneous Stock; IGF1, insulin-like growth factor 1;i.p., intraperitoneal; LH, luteinizing hormone; NOS, not otherwise specified; PbB, bloodlead concentration; PND, post-natal day; p.o., per os (oral administration); SRIF, somatostatin; StAR,steroidogenic acute regulatory protein.

# AX5-60 

# ANNEX TABLES AX5-5

# AX5-61Table AX5-5.1. In Vivo and In Vitro Studiesof the Effects of Lead Exposure onProduction and Metabolism of ReactiveOxygen Species, Nitric Oxide, and Soluble Guanylate CycleasePb ExposureMeasured ParametersReferenceSpecies/Tissue Age/Weight n Dosage Duration Pb Level CVS Other Interventions ResultsKhalil-Manesh et al.(1994)Male SDrats200 g N/A Pb-acetate,100 ppm inwater6 mo7±3.6 μg/dBP, tail art.ring responseto NEET-3, cGMP DMSA RXPb caused HTN,↑ET3,↓U cGMP (NS) (noeffect on NE reactivity).DMSA Rxlowered BPand Vasc response to NEand raised cGMPGonick et al.(1997)Male SDrats2 mo200 g6 Pb-acetate,100 ppm inwater3 mo12.4±1.8 μg/dLBP cGMP, NO2+NO3, ET-1,ET-3, MDA,eNOS, iNOS— HTN,↑MDA,↑eNOS,↑iNOS (protein andactivity in kidney)Ding et al.(1998)Male SDrats2 mo N/A Pb-acetate,100 ppm inwater3 mo3.2±0.2 μg/dLBP Urine NO2+NO3,plasmaMDADMSA (0.5% H2O)H2 wks, i.v.infusions of L.Arg., SOD and SNPPb caused HTN,↓urineNO2+NO3,↑plasmaMDA. DMSA loweredBP, blood Pb and MDA+ raised urine NO2+NO3.L-Arg lowered BPand MDA, raisedNO2+NO3, SNP loweredBPVaziri (1997) Male SDrats190 g12 Pb-acetate,100 ppm inwater3 mo17±9 μg/dLBP Plasma MDAurine NO2+NO3Antioxidant Rx(Lazaroid)Pb caused HTN,↑MDA,↓urine NO2+NO3inuntreated animals.Antioxidant RximprovedHTN, urine NO2+ NO3and lowered MDAwithout changes in bloodPb levelDursun(2005)Male SDrats24 Pb acetate8 mg/kg IP2 wks BP, RBF Ur Na, UrNO2+ NO3,24 hr UrNa(Na+intakeNot given )↑BP,↓RBF,↓UrNO2+NO3, unchanged UrNa+

# AX5-62Table AX5-5.1 (cont’d). In Vivo and In Vitro Studies of theEffects of Lead Exposure on Production and Metabolism ofReactive Oxygen Species, Nitric Oxide, and Soluble Guanylate CycleasePb ExposureMeasured ParametersReferenceSpecies/Tissue Age/Weight n Dosage Duration Pb Level CVS Other Interventions ResultsVaziri et al.(1999b)Male SDrats200 g 6 per groupper time pointPb-acetate,100 ppm inwater3 mo8.2±.8 and10.8±1 μgper g. Kidneytissue inuntreated andantiox-treatedgroupsBP Aorta andkidney eNOSproteinabundance, UrNO2+ NOSubgroupstreated with high-dose vitamin EPb exposure resulted in atime-dependent rise inBP, aorta and kidneyeNOS and iNOS. Thiswas associated w/aparadoxical fall in NOavailability (Ur NO2±NO3). Antioxidant Rxattenuated upregulationof iNOS and eNOS andraised NO availability.Vaziri et al.(2001)Male SDrats200 g 6 per group Pb acetate 3 mo N/A BP Aorta, heart,kidney and brainNOS isoforms,urine NO2+NO3Subgroupsstudied after 2wks of Rxw/tempol andthose studied 2wks aftercessation oftempol RxPb exposure resulted inrises in BP, eNOS, iNOSand nNOS in the testedtissues +↓urine NOx.Tempol administrationattenuated HTN, reducedNOS expressions andincreased urine NOx.The effects of tempoldisappeared within 2 wksof its discontinuation.Vaziri andDing (2001)HumancoronaryendothelialcellsN/A$4 perexperiment0 and 1 ppmPb acetate24 hrs w/Pbor Na acetatefollowedby 24 hrsw/tempol orvehicle1 ppm medium N/A eNOSexpressionCo-treatmentw/O2•scavenger,tempolPb exposure for 48 hrupregulated eNOSexpression. Co-treatmentw/ tempol resulted indose-dependent reversalof Pb-inducedupregulation of eNOSbut had no effect oncontrol cells.

# AX5-63Table AX5-5.1 (cont’d). In Vivo and In Vitro Studies of theEffects of Lead Exposure on Production and Metabolism ofReactive Oxygen Species, Nitric Oxide, and Soluble Guanylate CycleasePb ExposureMeasured ParametersReferenceSpecies/TissueAge/Weight n Dosage Duration Pb Level CVS Other Interventions ResultsVaziri et al.(1999a)Male SD rats 200 g 6 per group 100 ppm inwater3 mo8.3–10.8 μg/gkidney tissueBP Urine NO2+NO3, tissue andplasmanitrotyrosine(marker ofNO-ROSinteraction).Antioxidant Rx(Vit E)Pb exposure raised BP,reduced Ur NO2+ NO3and increasednitrotyrosine abundancein plasma, heart, kidney,brain and liver. Anti oxRxameliorated HTN,lowered nitrotyrosine andraised Ur NO2+ NO3.Vaziri et al.(2003)Male SD rats 200 g 6 per group 100 ppm inwater3 mo N/A BP Urine NO2+NO3, kidney,heart, brainSOD, catalase,GPX, NAD(P)HoxidaseabundanceTempol (O2•scavengerinfusion)Pb caused HTN,↑NAD(P)H oxidase(gp91phox),↑SOD, unchanged catalase andGPX,↓UrNO2+ NO3.Tempol resulted in↓BP+↑urine NO2+ NO3inPb-exposed but notcontrol rats.Ni et al.(2004)Culturedhumancoronaryendothelial andVSM cells.N/A$4 perexperiment0,1 and 10ppm PbacetateShortexposure(5–30 min)and longexposure(60 hr)0, 1, 10 ppm N/A O2•and H2O2productionsSOD, catalase,GPX andNAD(P)Hoxidase(gp91phox)None Short-term incubationwith Pb at 1 and 10 ppmraised O2•andH2O2productions by bothendothelial and VSMcells, long-termincubation resulted infurther rise in H2O2generation andnormalization ofdetectable O2y•.This wasassociated with increasesin NAD(P)H oxidase andSOD and reduced orunchanged catalase andGPX.

# AX5-64Table AX5-5.1 (cont’d). In Vivo and In Vitro Studies of theEffects of Lead Exposure on Production and Metabolism ofReactive Oxygen Species, Nitric Oxide, and Soluble Guanylate CycleasePb ExposureMeasured ParametersReferenceSpecies/TissueAge/Weight n Dosage Duration Pb Level CVS Other Interventions ResultsDing et al.(2001)Male SD rats 2 mo200 gN/A 100 ppm 3 moBlood Pb 12.4±1.8 μg/dL vs. 1mg/dL incontrolsBP Response toDMTUadministration,tissuenitrotyrosine,hydroxyl radicali.v. infusion ofDMTUPb caused HTN,↑plasmanitrotyrosine,↑plasma.OHconcentration all reversedwith .OH-scavenger,DMTU infusionDing et al.(2000)Cultured rataortaendothelialcellsN/A$4experiment0–1 ppm1, 2, 24, 84 hr0–1 ppm culturemediaN/A Hydroxyl radicalproduction usingthe followingreaction (NaSalicylate + OH→2,3dihydroxybenzoic acid),MDANone Pb exposure resulted inconc-dependent rise inMDA and OHproduction by culturedendothelial cells.Attri (2003) Male WistarKyoto rats150–200 g10 pergroupPb acetate,100 ppm inwater±Vit C 20mg/d/rat1–3 moBlood Pb1.5 mg/dL at1 mo2.4 mg/dL at2 mo4.1 mg/dL at3 moBP Total antioxidantcapacity, ferricreducingantioxidantpower, NOmetabolites,MDA,8-hydroxyguanosineResponse tovitamin C.Pb caused↑BP,↑MDA,↑DNA damage/oxidation,↓NOx,↓antioxidant and ferricreducing antioxidant.Concomitant Rxwith VitC ameliorated allabnormalities.Malvezzi(2001)Male Wistarrats5–6 wks(170 g)4–10 pergroupPb acetate750 ppm inwater100 days Blood, bone,kidney, aorta,liverBP— Response to L.arg, DMSA, L.arg .+ DMSA(given togetherw/Pb in last30 days↑BP w/Pb, partial↓BPw/L. Arg or DMSA,greater reduction w/both,blood and aorta PBremained↑in all butDMSA + L. Arg group.Significant Pbmobilization shown inother organs.

# AX5-65Table AX5-5.1 (cont’d). In Vivo and In Vitro Studies of theEffects of Lead Exposure on Production and Metabolism ofReactive Oxygen Species, Nitric Oxide, and Soluble Guanylate CycleasePb ExposureMeasured ParametersReferenceSpecies/Tissue Age/Weight n Dosage Duration Pb Level CVS Other Interventions ResultsKhalil-Manesh et al.(1993b)Male SDrats8 wks N/A Pb acetate 100 or5000 ppm inwater1–12 mo29±4 μg/dLBP, vascularcontractility toNE in vitrocGMP, ET-3, ANP — Pb caused HTN,↓serum and urinecGMP,↑serum ET-3without changing ANPor response to NEMarques et al.(2001)MaleWistar rats3 mo 20 Pb acetate 5 ppm±Vit C (3mmol/L) inwater30 days N/A BP, arch-, SNPvasorelaxationresponse in aortaringssGC protein mRNAand activity.cGMP production,eNOS proteinCoTxwith Vit C Pb caused HTN,↓relaxation to Ach andSNP,↑eNOS,↓sGCprotein mRNA andactivity. Theseabnormalities wereprevented byantioxidant Rx.Farmand et al.(2005)Male SDrats200 g 8 Pb acetate 100ppm in water3 mo N/A BPAorta sGC, SOD,catalase,glutathioneperoxidase—↓sGC,↑CuZn SODactivity, unchangedcatalase and GPXactivities.Courtois et al.(2003)RatthoracicaortaN/A 6/experiment0–1 ppm24 hr0–1 ppmcGMPproductionsGC expression,superoxideproduction, COX-2Vit C, COX-2inhibitorPb caused↓sGC,↓cGMP,↑O2,↑COX-2.All abnormalitiesimproved by Vit C.COX-2 inhibitorimproved sGCexpression but not O2production.

# AX5-66Table AX5-5.2. Studies of the Effectsof Lead Exposure on PKC Activity, NFkB Activation, and ApoptosisPb ExposureMeasured ParametersReferenceSpecies/TissueAge/Weight n Dosage Duration Pb Level CVS Other Interventions ResultsWatts et al.(1995)Isolated rabbitmesentericarteryN/A5–6 sets perexperimentPb acetate10−10−10−3MImmediate(contraction)5−10−10−3MmediumVascularcontractionPreincubationw/PKCactivators, PKCinhibitor orverapamil for30–60 min +endotheliumdenudationPb acetate inducedcontraction which waspotentiated by PKCactivators andattenuated by PKCinhibitor (role ofPKC). CCBattenuated Pb-inducedcontraction(contribution of Ca2+entry). Removal ofendothelium did notaffect Pb-inducedvasoconstriction.RodríguezIturbe et al.(2005)Male SD rats 200 g 8 Pb group9 controlsPb acetate100 ppm indrinkingwater3 mo N/ANFkB activation,apoptosis, Ang IIpositive cells,macrophage/T cellinfiltration andnitrotyrosine stainingin renal tissuePb-exposedanimalsshowedtubuloniterstitialaccumulation ofactivated T-cells,macrophages and AngII positive cells, NFkBactivation increasedapoptosis andnitrotyrosine stainingin the kidney.

# AX5-67Table AX5-5.3. Studies of the Effects of LeadExposure on Blood Pressure and Adrenergic SystemPb ExposureMeasured ParametersReferenceSpecies/TissueAge/Weight n Dosage Duration Pb Level CVS Other Reference Species/TissueChang et al.(1997)Wistar rats190–200 g20 Pb acetate0.5% indrinkingwater2 moBlood 29.1±1.9 μg/dLaorta; 1.9±0.2 μg/gBP Plasmacatecholamines +aorta;βreceptorbinding assay andcAMP generation— Pb exposure causedHTN, elevated plasmaNE (unchangedplasma Epi).↓isoproterenolstimulated plasmacAMP,↓βreceptordensity in aorta.Tsao et al.(2000)Wistar rats190–200 g70 Pb acetate0–2% indrinkingwater2 mo Blood, heart,aorta, kidneyBP,βagoniststimulatedcAMPproduction(10 μMisoproterenolin vitro)pl NEpi, cAMPβreceptor densities— Pb exposure raised BPand pl NE + loweredaorta and heartβreceptor density, basaland stimulated cAMPproductions +increased kidneyβreceptor density andbasal and stimulatedcAMP productions.Carmignaniet al. (2000)Male SD rats 3 mo24 60 ppm10 moBlood 22.8±1.2 μg/dLBP, HR,cardiaccontractility(dP/dt), bloodflowPlasma NE, Epi,dopamine, monoamineoxidase (MAO)activity, histology— Pb exposure raised BPand dp/dt, loweredcarotid blood flow, (nochange in HR) raisedplasma NE and Epiand MAO (all tissues)lowered plasma NOx+↓aorta mediathickness,↑lymphocyteinfiltration inperiaortic fat,nonspecific change inkidney (congestion,edema, rare prox.tubular cell necrosis).

# AX5-68Table AX5-5.3 (cont’d). Studies of the Effects of Lead Exposure on Blood Pressure and Adrenergic SystemPbExposureMeasured ParametersReferenceSpecies/TissueAge/Weightn Dosage Duration Pb Level CVS Other Interventions ResultsLai et al.(2002)Male SD rats 300 g AcuteresponseIn vivo:Intrathecalinjection ofPbCl2, 10–100 μM.In vitro:Thoracic cordslices exposedto 5–50 μMPbCl2— — BP, HR, (In vivo)w/withoutganglionic blockade(Hexomethonium)Electophysiologic measures (Invitro)before/aftersaline washout— In vivo: IT injectionof PbCl2 raised BPand HR. This wasreversed by ganglionicblockade. In vitro: Pbraised excitatory andlowered inhibitorypostsynaptic potentialswhich were reversedby removal of Pb(saline washout)Chang et al.(2005)Male Wistarrats10 wks 70 2% Pb acetate(drinkingwater)2 mo,observed for7 mo aftercessationBlood:85 μg/dLAorta:8 μ/g/gHeart:1 μg/gKidney:60 μg/gBP Plasma NE,βrecaptor density(aorta, heart,kidney)Cessation of PbexposurePb exposure raisedBP, plasma NE, andrenal tissueβreceptorand loweredaorta/heartβreceptordensity. Plasma andtissue Pb fell to near-control values within 7mo. after Pb cessation.This was associatedwith significantreductions (notnormalization) of BP,plasma NE and partialcorrection of tissueβreceptor densities(Bone Pb was notmeasured).

# AX5-69Table AX5-5.4. Studies of the Effects of Lead Exposureon Renin-angiotensin System, Kallikrein-Kinin System,Prostaglandins, Endothelin, and Atrial Natriuretic Peptide (ANP)PbExposureMeasured ParametersReferenceSpecies/TissueAge/Weightn Dosage Duration Pb Level CVS Other Interventions ResultsCarmignaniet al. (1999)Male SD rats Weaning 16 Pb acetate60 ppmdrinking water10 moBlood 24.2±1.8 μg/dLBP, HR, carotidblood flowPlasma ACE,Kininase Kallikreinactivities dp/dt— Pb exposure raised BPand dp/dt, lowered carotidblood flow withoutchanging HR. This wasassociated with markedincrease in plasma ACE,Kininase II and Kininase Iactivities.Sharifi et al.(2004)Male SD rats 200 g 32 Pb acetate100 ppmdrinking water2–8 wks—BP ACE activity inplasma, aorta, heart,kidney— Pb exposure raised BP,ACE activity in plasmaand tested tissuesmarkedly increasedpeaking within 2–4 wksfollowed by a decline tosubnormal values.Gonick at al.(1998)Male SD rats 2 mo 21 Pb acetate100 ppmdrinking water12 wks —BP Urinary Tx B2, 6-keto PGF1— Pb exposure raised BP butdid not affect urinary PGmetabolite excretionrates.Dorman andFreeman(2002)VSMC(rat aorta)— — 0.0, 0.02, 0.2,2.0 mg/dLup to 48 hrs 0.0 to 2mg/dL— Arachidonic acid(AA), DNAsynthesis, cellproliferation + cellviabilityAng II, FCS Pb augmented Ang IIstimulated AA release ina concentrationdependent fashion. Atlow concentrations, Pbaugmented Ang IIstimulated DNA synthesisand lowered cell count inunstimulated cells.Giridhar andIsom (1990)Male SD rats150–175 g20 Pb acetate 0.01,0.01, 0.5, 1.0mg/Kg, BiW, IP30 days —— ANF— Pb exposure resulted influid retention (↓urineflow + unchanged fluidintake + weight gain).This was associated withdecreased plasma andhypothalamic ANF levels.

# AX5-70Table AX5-5.5. Studies of Effect ofLead on Vascular ContractilityPbExposureMeasured ParametersReferenceSpecies/TissueAge/Weightn Dosage Duration Pb Level CVS Other Interventions ResultsShelkovnikovand Gonick(2001)Rat aorta ringsPb acetate10−8to 10−4Shortincubations— Vasoconstriction/vasodilationPb acetated did not causevasoconstriction and didnot modify the responseto NE, isoproterenol,phorbol ester oracetylcholine but raisedcontractile response tosubmaximal Ca2+concentrationPurdy et al.(1997)Male SD rats 8 wks Pb acetate 100ppm in water3 mo — BP Aorta ringresponse to NE,phenylephrine,acetylcholine, andnitroprussidePb exposure raised BP.Aorta ringvasoconstrictive responseto NE and phenylephrineand vasodilatoryresponse to acetylcholineand nitroprusside wereunchanged.Oishi et al.(1996)Male WistarratsPbacetate1–3 moMesenteric artand aortaresponse toacetylcholine inpresence orabsence of NOSinhibitor (L-NAME)Vasorelaxationresponseto acetylcholine inpresence of L-NAMEwas significantly reducedin mesenteric art, but notaorta of Pb-exposedanimals (Inhibition ofhyperpolarizing factor)Valencia et al.(2001)Wistar ratthoracic aortarings7 wks 6 sets/experimentPb acetate0.1–3.1 mMRapidresponsein vitro— InvitrocontractileresponsePb induced aconcentration-dependentvasoconstriction in intactand endothelial-denudedrings in presence orabsence ofα-1 blocker,PKC inhibitor, L. typeCa2+channel blocker orintra- and extracellularCa2+depletion.However, the responsewas abrogated bylanthanum (a general Cachannel blocker)

# AX5-71Table AX5-5.6. Effects of Lead on Cultured Endothelial Cell Proliferation, Angiogenesis, andProduction of Heparan Sulfate Proteoglycans and tPAPbExposure MeasuredParametersReferenceSpecies/TissueAge/Weightn Dosage Duration Pb Level CVS Other Interventions ResultsKaji et al.(1995a)— 4 sets perexperimentPb nitrate5–50 μM24 hrs—EndothelialdamageCo-incubationwith cadmiumAddition of Pb aloneresulted in milddeendothelialization ofthe monolayers andmarkedly increasedcadmium-associatedendothelial damage.Kaji et al.(1995b)Bovine aortaendothelialcells—4–5 sets perexperimentPb nitrate0.5–5 μM24 hrs—3H-thymidineincorporation, cellcount,morphology,LDH releaseStimulationw/βFGF andαFGFIncubation w/Pb resultedin a concentrationdependent reduction ofDNA synthesis and cellcount, caused some shapechange (polygonal→spindle) and reducedβFGF- andαFGFmediated proliferation.Fujiwara et al.(1998)Bovine aortaendothelialcells— 6 set perexperimentPb nitrate5 and 10 μM48 hrs—Appearance ofcells in denudedareas ofmonolayer, DNAsynthStimulationw/ZnPb inhibited appearanceof endothelial cells in thedenuded section ofmonolayer and attenuatedthe healing response toZinc.Kishimotoet al. (1995)Humanumbilical veinendotheliacells— 3 sets perexperimentPb acetate1–100FM24 hrs—Formation oftube-likestructures (angiogenesis assay, onMatrigel (BM)— Pb inhibited tubeformation concentrationdependently and tubelengthening timedependently.Ueda D. et al.(1997)Humanumbilical veinendothelialcells— 3 sets perexperimentPb acetate1–100 μM24 hrs—Tube formationon MatrigelmatrixPKC activatorand inhibitorPb inhibited tubeformation concentrationdependently and tubelengthening timedependently. Theseeffects were independentof PKC.

# AX5-72Table AX5-5.6 (cont’d). Effects ofLead on Cultured Endothelial Cell Proliferation, Angiogenesis, andProduction of Heparan Sulfate Proteoglycans and tPAPbExposureMeasuredParametersReferenceSpecies/TissueAge/Weightn Dosage Duration Pb Level CVS Other Interventions ResultsFujiwara andKaji(1999)Bovine aortaendothelialcells—4 sets perexperimentPb nitrate0.5, 1, 2 μM12–48 hrsβFGF production/distributionHeparan sulfateproduction (sulfateincorporation)DNA synthesis (cellproliferation)βFGF binding assayHeparin, AntiβFGF antibodyPb and anti-βFGF aloneor together equallyreduced DNA synthesis.PB did not changeendogenousβFGFproduction but reducedits HSPG-boundcomponent. This wasdue to diminishedheparan sulfate synthesisas opposed tointerference withβFGFbinding property.Kaji et al.(1991)Bovine aortaendothelialcells—4–5 sets perexperimentPb nitrate0, 1–20 μM24–48 hrsGlycosaminoglycan(GAG) synthesis(sulfate incorporation)At 10FM, Pbsignificantly reducedproduction of totalGAGs. Heparan sulfatewas reduced moreseverely than otherGAGs. Cell surfaceGAG was reduced moreseverely than found inthe medium.Kaji et al.(1997)Bovine aortaendothelialcells(confluent)—N/A Pb chloride10 M24 hrs N/ASynthesis of heparansulfate proteoglycans(HSPGs) and their coreproteinsIn confluent cells, Pbsuppressed incorporationof precursors into HSPGin the cell layer to agreater extent thanchondroitin/dermatansulfate proteoglycans. Pbsuppressed lowmolecular weight HSPGsmore than the highmolecular weightsubclass. The coreproteins were slightlyincreased by Pbexposure.

# AX5-73Table AX5-5.6 (cont’d). Effects ofLead on Cultured Endothelial Cell Proliferation, Angiogenesis, andProduction of Heparan Sulfate Proteoglycans and tPAPbExposure MeasuredParametersReferenceSpecies/TissueAge/Weightn Dosage Duration Pb Level CVS Other Interventions ResultsFujiwara andKaji(1999)Bovine aortaendothelialcells (growing10% BCS)—4 sets perexperimentPb nitrate0.1 μM48 hrsSulfate andglucosamineincorporation in GAGs,quantification of highand low MW-HSPG,identification ofperlecan core proteinIn growing cells, Pbdepressed high-MWHSPGs production buthad little effect on lowMW HSPGx (~50 KD).The core protein ofperlecan (400 KD) wassignificantly reduced byPb exposure.Kaji et al.(1992)Humanumbilical veinendothelialcells(confluent)—5 sets perexperiment0.01–1 μMt-PA release, DNAsynth, protein synth(leucine incorporation)Thrombin andET-1stimulationsPb exposure reducedbasal and thrombinstimulation t-PA releaseand worsened ET-1induced inhibition of tPA release.

# AX5-74Table AX5-5.7. Studies of the Effect of Leadon Cultured Vascular Smooth Muscle CellsPbExposure MeasuredParametersReferenceSpecies/TissueAge/Weightn Dosage Duration Pb Level CVS Other Reference Species/TissueFugiwaraet al. (1995)Bovine aortavascularsmoothmuscle cell4 sets perexperimentPb nitrate0.5–10 μM24 hrs—DNA synthesis Coincubationw/βFGF,αFGF. pDGFPb caused aconcentration-dependentincrease in DNAsynthesis. Co-incubationw/βFGF and Pb resultedin an additive stimulationof VSMC DNA synth.However, Pb inhibitedPDGF andαFGFinduced DNA synthesis.Carsia et al.(1995)Rat aortaVSMC cells(80–90%confluent)$3 sets perexperimentPb citrate 100and 500 μg/LTime toconfluence(~90% forcontrolexperiments)Cell density (cell#/Cm2), cellmorphology,membrane lipidanalysis, receptordensities (Ang-II,α,β, ANPAt low concentration, Pbcaused VSMChyperplasia, phenotypictransformation fromspindle-to-cobblestone(neointima-like) shape,reduced Ang II receptordensity without changingα,β, ANP receptors,increased arachidonicacid content of cellmembrane.Yamamotoet al. (1997)Human aortaVSMC andfetal lungfibroblasts(confluent)5 sets perexperimentPb chloride0.5–10 μM24 hrst-PA and PAI-1releaseAt 2 μM or higherconcentrations, Pbresulted in aconcentration-dependentdecline in t-PA release inboth cell types. Pbincreased PAI-1 releasein fibroblasts but loweredPAI-1 in VSMC.

# AX5-75 

# ANNEX TABLES AX5-6

# AX5-76Table AX5-6.1. Genotoxic/Carcinogenic Effects of Lead—Laboratory Animal StudiesCompound Dose and DurationCell Type Co-exposureEffectsReferencePb acetate0.5, 5, or 25 ppm given in drinkingwater–duration not given.Number of animals per group wasnot given.Female C3HSt miceinfected with MMTV(Murine mammarytumor virus)–age notgivenSelenium, 0.15–1 ppm (duration notgiven) in diet ( Seprevents spontaneoustumors in these mice)Pb acetate exposed mice exhibited greater mortality unrelated tothe tumor formation.25 ppm suppressed tumor formation, but increased theaggressiveness of the tumors.5 ppm increased tumor formation, but had no effect on growthrates.0.5 ppm with low selenium exhibited 80% tumor formation andreduced weight gains that recovered.0.5 ppm with high selenium exhibited normal weight gain, buttumor incidence still reached 80%.Control data described as “significantly lower” but not given.Methods poorly describedand data not shown.Schrauzer (1987)Pb acetate0–4000 ppm given in drinkingwater for 104 wks.Wild type (WT) andmetallothionine null (MTnull) miceNone Renal proliferative lesions were much more common and severein MT null mice than WT mice. MT null mice could not formrenal inclusion bodies even withprolonged Pb exposure and thiscould have contributed to increase in the carcinogenic potentialof Pb.Waalkes et al.(2004)Pb acetate 50, 250, or 1000 ppm given indrinking water for 15 wks.Number of mice per group in initialexposures not given.Number of mice at analysis rangedfrom 19–25.Female albino SwissMice–3 wks oldUrethane 1.5 mg/ggiven i.p.No signs of Pb poisoning. No Pb effects on growth or weightgain.Urethane added to induce lung tumors.Pb did not affect urethane metabolism.Pb did not affect number of tumors or affect tumor size.Pb alone was not evaluated.Pb levels did increase in tissues.Blakley(1987)

# AX5-77Table AX5-6.1 (cont’d). Genotoxic/CarcinogenicEffects of Lead—Laboratory Animal StudiesCompound Dose and DurationCell Type Co-exposureEffectsReferencePb acetate 50 or 1000 ppm 50 or 1000 ppmgiven in drinking water for280 days.Number of mice pre group in initialexposures not given.Number of mice at end were 50 perdose.Female albino SwissMice–8 wks oldNone Mice have high rate of spontaneous leukemia from endemic viralinfection.No signs of Pb poisoning. No Pb effects on growth or weightgain.Pb did increase leukemia-related mortality possibly due toimmunosuppression.Pb levels did increase in tissues.Data indicate that Pb may be immunosuppressive, though theexact mechanism is not understood.Blakley(1987)Pb acetate 60 mg/kg injected s.c. weekly for5 wks followed by observation for80 wks. 13 treated and 14 controlrats.Fisher F344/NSle rats–3 wks oldNone Pb induced tumors at the site of injection in 42% of ratsthough data was not shown.Control data not indicated or shown.Pb accumulated in tumor tissue, tooth, and bone. This datawas shown.Teraki andUchiumi (1990)Pb acetate 1 or 100 μg/L given in the drinkingwater for 31 wks8 animals per groupMale Wistar Rats—weanlings0.2–4 % calciumcarbonate given in thediet for 31 wks.No differences in drinkingwater or food consumption.High Pb and high calcium reduced growth.No deaths in low calcium groups.10/24 rats from high calcium dietdied (4 from controls and 3each from Pb groups). All 10 had kidney or bladder stones.0/8 rats in low calcium no Pb had kidney pathology2/8 rats in low calcium low Pb had nephrocalcinosis.7/8 rats in low calcium high Pb had nephrocalcinosis.3/4 rats in high calcium no Pb had nephrocalcinosis.1/5 rats in high calcium low Pb had a renal pelvic carcinoma.3/5 rats had nephrocalcinosis.3/5 rats in high calcium high Pb had transitional cellhyperplasia. 2/5 rats had invasive renal pelvic carcinoma.Pb tissue levels were same regardless of dietary calciumlevels.Bogden et al.(1991)

# AX5-78Table AX5-6.2. Genotoxic/Carcinogenic Effects of Lead—Human Cell CulturesCompound Dose and Duration Cell Type Co-exposureEffectsReferencePb chromate Anchorage Independence(0.1–1 μM for 48 h)Human ForeskinFibroblastsIn H-MEM +15% FCSNone Pb chromate-induced concentration-dependent increase inanchorage independence.Biedermann andLandolph (1987)Pb chromate Anchorage Independence(0.1–1 μM for 48 h)Human ForeskinFibroblastsIn H-MEM +15% FCSNone Pb chromate-induced concentration-dependent increase inanchorage independence.Biedermann andLandolph (1990)Pb chromate Morphological Transformation(2 μg/mL for 24 h, performed3 times immediately afterpassage)Anchorage Independence (0.2–2 μg/mL or cells isolated duringmorphological transformation)Neoplastic Transformation (cellsisolated during morphologicaltransformation)HOS TE 85 in DMEM+ 10% FBSNone Pb chromate induced fociof morphological transformationafter repeated exposure and passaging.Pb chromate did not induce anchorage independence, butcells from the foci obtained during morphologicaltransformation.Pb chromate did not induce neoplastic transformation in thecells from the foci obtained during morphologicaltransformation.Studied as a chromate compound. Role of Pb not mentionedor considered.Sidhu et al. (1991)Pb acetate Anchorage Independence(500–2000 μM for 24 h)Human ForeskinFibroblasts (Chinese)In DMEM +10% FCS3-aminotriazole (3-AT)(80 mM to inhibitcatalase)Pb acetate-induced concentration-dependent increase inanchorage independence.Anchorage independence notaffected by 3-AT.Hwua and Yang(1998)

# AX5-79Table AX5-6.3. Genotoxic/Carcinogenic Effects ofLead—Carcinogenesis Animal Cell CulturesCompound Dose and DurationCell Type Co-exposureEffectsReferencePb acetate Morphological Transformation(10–50 μM for 48 h)Primary SHE cells inAMEM + 10% FBSNonePb acetate was weakly positive inducing a 0.19–1.6%increase in transformation. There was a weak doseresponse. There were no statistical analyses of these data.Zelikoff et al. (1988)Pb chloride Morphological Transformation(doses not given)C3H10T1/2 cells inEMEM +10% FBSNone Pb chloride did not induce morphological transformation. Patierno et al. (1988),Patierno andLandolph (1989)(both papers presentthe same data)Pb chromate Enhancement of SimianAdenovirus (SA7) inducedmorphological transformation.(80–1,240 μM for 20 h)Primary SHE cells inDMEM + 10% FBSNonePb chromate enhanced SA7-induced morphologicaltransformation.Studied as a chromate compound. Role of Pb notmentioned or considered.Schechtman et al.(1986)Pb chromate Morphological Transformation(10–50 μM for 24 h)Anchorage Independence for cellsisolated during morphologicaltransformationNeoplastic Transformation for cellsisolated during morphologicaltransformation.C3H10T1/2 cells inEMEM + 10% FBSNone Pbchromateinducedmorphological and neoplastictransformation.Cells exhibiting morphological transformation grew in softagar and grew in nude mice.Studied as a chromate compound.Patierno et al. (1988)Patierno andLandolph (1989)(both papers presentthe same data)Pb chromate(and pigmentscontaining Pbchromate)Morphological Transformation(0.04–8 μg/mL as Cr for 7 days)Anchorage Independence for cellsisolated during morphologicaltransformationNeoplastic Transformation for cellsisolated during morphologicaltransformationPrimary SHE cells inDMEM + 10% FCSNone Pbchromateinducedmorphological and neoplastictransformation.Cells exhibiting morphological transformation grew in softagar and grew in nude mice.Studied as a chromate compound.Elias et al. (1989)Pb chromate Morphological Transformation(0.02–0.88 μg/mL as Cr for 7 days)Primary SHE cells inDMEM + 10% FCSNonePb chromate induced morphological transformation morepotently (9-fold) than other chromate compounds.Elias et al. (1991)

# AX5-80Table AX5-6.3 (cont’d). Genotoxic/Carcinogenic Effects of Lead—Carcinogenesis Animal Cell CulturesCompound Dose and DurationCell Type Co-exposureEffectsReferencePb nitrate Morphological Transformation(0.04–8 μg/mL as Cr for 7 days)Primary SHE cells inDMEM + 10% FCSCalcium chromate Pb nitrate alonedid not induce significant levels oftransformation.Pb nitrate plus calcium chromate increased the potency ofcalcium chromate to that of Pb chromate. Data suggest Pbions are synergistic with chromate ions in inducingneoplastic transformation.Elias et al. (1991)AbbreviationsCellsSHE—Syrian hamster embryo;C3H10T/12 cells are a mouse embryo cell lineMedium and ComponentsAMEM—Alpha Minimal Essential Medium;DMEM—Dulbecco’s Minimal Essential Medium;EMEM—Eagle’s Minimal Essential Medium;FBS—Fetal Bovine SerumFCS—Fetal Calf SerumH-MEM—Minimum essential medium/nutrient mixture–F12-HamHOS TE—Human osteosarcoma cell line TEDifferences between the serum are unclear as insufficient details are provided by authors to distinguish.

# AX5-81Table AX5-6.4. Genotoxic/Carcinogenic Effects ofLead—Genotoxicity Laboratory Animal Studies.Compound Dose and DurationSpeciesCo-exposureEffectsReferencePb acetate 2.5 mg/100 g given i.p.as daily injection for 5–15 daysor10–20 mg/100 g given i.p.as single injection andanimals studied after15 days5 animals per group.Chromosome damage inbone marrowFemale Norway RatSelenium (0.012–0.047 mg/100g or0.094–0.188 mg/100 ggiven i.p. with Pb)Pb induced chromosome damage after chronic treatment. Itwas not dose dependent as only 1 dose was studied. Theeffects of selenium on Pb effects are unclear as seleniumalone induced substantial chromosome damage.The single dose exposure also induced chromosome damage,but untreated controls were not done in this regimen. Thereis some mention that this dose regimen is toxic to the animalsas selenium modulated the lethal effects, but no explanationof how many animals died.Chakrabortyet al. (1987)Pb acetate25–400 mg/kg given i.p.as single injection andanimals studied after 24 hFor some chromosomedamage studies animalswere treated with 25–200 mg/kg given i.p. asa series of 3, 5, or 7 dailyinjections and animalsstudied after 24 h after thelast injection.5 animals per group.Chromosome damage,sister chromatid exchange,in bone marrow andspermatocytes.Male Swiss Mice,9–12 wks oldNone Pb induced chromosome damage in a dose dependent mannerat 100–400 mg/kg after a single dose or repeated doesexposure in bone marrow cells.In spermatocytes, Pb also induced chromosome damage in adose dependent manner at 50–400 mg/kg after a single doseor repeated dose exposure in bone marrow cells.Pb induced SCE at 50 and 100 mg/kg. A lower dose wasnegative and higher doses were not done.Fahmy (1999)Pb acetate 200 or 400 mg/kg given bygavage daily for 5 days5 animals per groupChromosome aberrations inbone marrow andspermatocytes.Male Swiss Mice,9–12 wks oldCalcium chloride (40 or80 mg/kg by gavagedaily for 3 days given2 wks after Pbexposure)Pb induced chromosome damage at both 200 and 400 mg/kgin bone marrow cells and spermatocytes. Calcium appearedto block this effect.Aboul-Ela (2002)

# AX5-82Table AX5-6.4 (cont’d). Genotoxic/Carcinogenic Effectsof Lead—Genotoxicity Laboratory Animal Studies.Compound Dose and DurationSpeciesCo-exposureEffectsReferencePb nitrate100–200 mg/kg given i.v.on 9th day of gestationonwards for 9 days.Mothers and fetusesanalyzed on G18.Group size not given.Resorptions, fetal viabilityand chromosome damage,SCE and NOR in themother and fetus wereexamined. Mother–bonemarrow; fetus liver or lung3 mothers and fetuses perdose were analyzed.ICR Swiss Webster Mice,6–8 wk oldNonePb levels were found in both mother and fetus indicating noproblems crossing the placenta.All doses indicated increasedresorption and decreasedplacental weights. No effects on fetal weight.Significant increase in SCE in mothers at 150 and 200 mg/kg.No increase in SCE in fetuses.Significant decrease in NOR in both mother and fetuses.No gaps or breaks in mothers or fetuses.Some weak aneuploidy at lowest dose.Some karyotypic chromosome damage was seen.No explanation of how manycells analyzed per animal(3 animals per dose were analyzed) as only 20–40 cells wereanalyzed.There was no dose response and no statistical analyses forchromosome damage. No details on how many animalsanalyzed for metaphase damage or how many cells peranimal.Data interpretation is also complicated as too few metaphaseswere analyzed 10–25 for SCE. Not given for CA.No detail on potential maternal toxicity.Nayak et al. (1989b)Pb nitrate 10, 20, or 40 mg/kg giveni.p. 24 h6 animals per group.Chromosome damage andMitotic Index in bonemarrowSwiss Albino Mice,8 wks oldPhyllanthus fruit extract(685 mg/kg) or ascorbicacid (16.66 mg/kg)given by gavage for7 daysPb nitrate increased the amount of chromosome damage ateach dose. But there was no dose response and a similarlevel of damage was seen for each dose.Phyllanthus fruit extract reduced the amount of damage ateach dose. Ascorbic acid reducedthe damage at the lowestdose but increased it at the higher doses.Higher concentrations of Pb nitrate reduced the mitotic index.This effect was reversed by ascorbate and Phyllanthus only atthe moderate dose.Dhir et al. (1990)Pb nitrate 5, 10, or 20 mg/kg giveni.p. 24 h6 animals per group.Chromosome damage inbone marrow.50 metaphases per animalfor a total of 300 (X6).Swiss Albino Mice,8 wks oldFerric chloride(18 mg/kg) given i.p.for 24 h administered1 h before, 1 h after, ortogether with Pb nitratePb nitrate increased the amountof chromosome damage in adose-dependent manner.Iron exhibited some modifications of Pb induced damage:If administered 1 h before Pb plus simultaneously it reducedthe damage. If administered with Pb only at same time itreduced damage in the lower doses. If Pb was started 1 hbefore iron there was no effect.Thus iron may antagonize Pb perhaps by blocking uptake.Dhir et al. (1992a)

# AX5-83Table AX5-6.4 (cont’d). Genotoxic/Carcinogenic Effectsof Lead—Genotoxicity Laboratory Animal Studies.Compound Dose and DurationSpeciesCo-exposureEffectsReferencePb nitrate 5 or 10 mg/kg given bygavage for 24 h6 animals per group.Chromosome aberrations inbone marrowSwiss Albino Mice,7–8 wks oldZirconium oxychloride(110 or 220 mg/kg)given by gavage for24 h administered 2 hbefore, 2 h after ortogether with Pb nitratePb nitrate increased the amountof chromosome damage in adose-associated manner.Zirconium induced a dose-associated increase inchromosome damage.Zirconium exhibited minimal modification of Pb nitrateinduced damage when administered 2 h before or after Pbnitrate.Administering the two together increased the damage.Dhir et al. (1992b)Pb nitrate 10, or 20 mg/kg given i.p.48 h12 animals per group.Micronucleus formation inbone marrowSwiss Albino Mice,6 wks oldPhyllanthus fruit extract(685 mg/kg) or ascorbicacid (16.66 mg/kg)given by gavage for7 daysPb nitrate increased the amount of micronuclei at both dosesin a dose-associated manner. The 48 h recovery time waslower than 24 h but still elevated.Phyllanthus fruit extract reduced the amount of damage atboth doses. Ascorbic acid reduced the damage at the lowestdose but increased it at the higher dose.Roy et al. (1992)Pb nitrate 10, 20, or 40 mg/kg giveni.p. 24 h5 animals per group.SCE in bone marrowSwiss Albino Mice,6–8 wks oldPhyllanthus fruit extract(685 mg/kg) or ascorbicacid (16.66 mg/kg)given by gavage for7 daysPb nitrate increased the amount of SCE in a dose-dependentmanner. Pb nitrate had no effect of the proliferative rateindex (consideration of metaphases in different divisionnumbers)Phyllanthus fruit extract and ascorbic acid reduced theamount of damage at each dose.Dhir et al. (1993)Pb nitrate0.625–80 mg/kg given i.p.for 12, 24 or 36 h12 animals per groupMicronucleus formation inbone marrow. 4000erythorocytes scored peranimalSwiss Albino Mice,6–8 wks oldNonePb nitrate induced micronuclei but they did not increase withdose.Pb induced more micronuclei in males than in females.The ratio of polychromatic to normochromatic erythrocyteswas elevated in Pb nitrate treated cells, but again did notincrease with dose.Jagetia and Aruna(1998)Pb nitrate0.7–89.6 mg/kg given bygavage for 24, 48, or 72 h,or 1 or 2 wks5 animals per group.Cell viability by trypan blueSingle strand breaks inwhite blood cellsSwiss Albino Mice,4 wks oldNoneViability was high (92–96%) at all doses.Pb nitrate induced single strand breaks but they did notincrease with dose. In fact the 3 highest doses were allsimilar in magnitude and less than the 5 lowest doses.The 5 lowest doses were also similar in magnitude.Devi et al. (2000)

# AX5-84Table AX5-6.4 (cont’d). Genotoxic/Carcinogenic Effectsof Lead—Genotoxicity Laboratory Animal Studies.Compound Dose and DurationSpeciesCo-exposureEffectsReferencePb acetate 10 mg/kg given by gavage5 times a week for 4 wks.10 animals per groupChromosome Aberrationswith 20 metaphases scoredper animalMale Wistar rats,30 days oldCypermethrin No effects on weight gain.Pb acetate induced an increase inaneuploidy, and the percentof cells with damage, but did not increase structural damageor alterations in organ weight.Cypermethrin and Pb together increased structuralaberrations that were predominately acentric fragments.However, this was compared to untreated controls and not theindividual treatments. Considering the individual treatments,the two together are less than additive.Nehez et al. (2000)

# AX5-85Table AX5-6.5. Genotoxic/Carcinogenic Effects of Lead—Genotoxicity Human Cell Cultures MutagenesisCompound Dose and Duration Cell TypeCo-exposureEffectsReferencePb acetate,In vitroCytotoxicity–tritiumincorporation (0.1–100 μM/mL for 2–24 h)Mutagenesis–HPRTmodified to labeling of6-thioguanine resistant cells(0.1–100 μM/mL for2–24 h)Human Keratinocytespooled in MEM and lowcalcium MEM + 2% FBSNoneDecrease in tritium incorporation at 10–100 μM/mL.6 μM/L was selected as the concentration to study as tritiumincorporation was highest and greater than control.Tritium incorporation in the presence of 6-thioguanine (TG)was optimal after 4 h Pb acetate exposure and 5 days ofexpression time. It was concluded that the significantincrease relative to control indicated mutations. Theargument made was that because these cells are TG resistantthey must be mutated. However, this argument was notproven by sequencing or colony formation in TG.Ye (1993)Pb acetateCytotoxicity (500–2,000 μM for 24 h)Mutagenicity–HPRT assay(500–2,000 μM for 24 h)Human ForeskinFibroblasts (Chinese)in DMEM +10% FCS3-aminotriazole (3-AT)(80 mM to inhibitcatalase)LC50 = 500 μM. Cytotoxicity not affected by 3-AT.Pb acetate was not mutagenic.Mutagenicity not affected by 3-AT.Hwua and Yang(1998)Pb chromate Mutagenicity as 6-thioguanine resistance(0.25–1 μM for 24 h)Human ForeskinFibroblastsIn EMEM +15% FCSNonePb chromate was not mutagenic.Biedermann andLandolph (1990)AbbreviationsMedium and ComponentsMEM—Minimal Essential Medium;DMEM—Dulbecco’s Minimal Essential Medium;EMEM—Eagle’s Minimal Essential Medium;FBS—Fetal Bovine SerumFCS—Fetal Calf SerumDifferences between the serum types are unclear as insufficient details are provided by authors to distinguish.

# AX5-86Table AX5-6.6. Genotoxic/Carcinogenic Effects of Lead—Genotoxicity Human Cell Cultures ClastogenicityCompoundAssay (Concentrationand Exposure Time)Cell Type and CultureMediumCo-exposure Effects ReferencePb chromate Chromosome aberrations(0.08–2 μg/cm2for 24 h)Human Foreskin Fibroblasts(Caucasian) in EMEM + 15% FBSNone Pb chromate induced chromosome damage in aconcentration dependent manner.This study was focused on chromate.Wise et al.(1992)Pb chromate Chromosome aberrations(0.1–5 μg/cm2for 24 h)Primary Human Lung Cells inDMEM/F12 + 15% FBSNone Pb chromate induced chromosome damage in aconcentration dependent manner.This study was focused on chromate.Wise et al.(2002)Pb chromate Chromosome aberrations(0.1–5 μg/cm2for 24 h)Primary Human Lung Cells andWTHBF-6—human lung cells withhTERT in DMEM/F12 + 15% FBSNone Pb chromate induced chromosome damage in aconcentration dependent manner.Effects were similar inboth cell types establishing the WTHBF-6 cells as a usefulmodel.This study was focused on chromate.Wise et al.,(2004a)Pb chromate Chromosome aberrations(0.1–5 μg/cm2for 24 h)WTHBF-6—human lung cells withhTERT in DMEM/F12 + 15% CCSVitamin C(2 mMco-exposurefor 24 h)Pb chromate induced chromosome damage in aconcentration dependent manner.Vitamin C blocked Cr ion uptake and the chromosomedamage after Pb chromate exposure.This study was focused on chromate.Xie et al. (2004)Pb chromate Chromosome aberrations(0.05–5 μg/cm2for 24 h)WTHBF-6—human lung cells withhTERT in DMEM/F12 + 15% CCSVitamin C(2 mMco-exposurefor 24 h)Pb chromate induced chromosome damage in aconcentration dependent manner.This study was focused on showing chromate and not Pbions were the clastogenic species.Wise et al.(2004b)Pb chromate Chromosome aberrations(0.05–5 μg/cm2for 24 h)WTHBF-6—human lung cells withhTERT in DMEM/F12 + 15% CCSNone Pb chromate induced chromosome damage in aconcentration dependent manner.This study was focused on comparing particulate chromatecompounds.Wise et al.(2005)

# AX5-87Table AX5-6.6 (cont’d). Genotoxic/Carcinogenic Effects of Lead—GenotoxicityHuman Cell Cultures ClastogenicityCompoundAssay (Concentrationand Exposure Time)Cell Type and CultureMediumCo-exposure Effects ReferencePb glutamate Pb ion uptake–ICPMS(250–2,000 μM for 24 h)Chromosome Aberrations(250–2,000 μM for 24 h)WTHBF-6—human lung cells withhTERT in DMEM/F12 + 15% CCSNone Pb glutamate induced a concentration-dependent increase inintracellular Pb ions.Pb glutamate did not induce chromosome damage.Wise et al.(2005)Pb glutamate Pb ion uptake–ICPMS(250–2,000 μM for 24 h)Mitotic Index(250–2,000 μM for 24 h)Growth Curve(250–2,000 μM for 24 h)Cell cycle Analysis(250–2,000 μM for 24 h)WTHBF-6—human lung cells withhTERT in DMEM/F12 + 15% CCSNone Pb glutamate induced a concentration-dependent increase inintracellular Pb ions.Pb glutamate increased the mitotic index, but inhibitedgrowth and did not induce chromosome damage.Radioactive PbionsNo furtherspecificationLET = 13,600keV/μMFluence of2H106particles/ cm2Chromosome AberrationsHuman Foreskin Fibroblasts inDF-12 + 10% FCSNone Pb induced chromosome damage that recurredwith time and cell passaging. Analysis limited to~25 metaphases.Focused on radioactive effects of PbMartins et al.(1993)AbbreviationshTERT is the catalytic subunit of human telomeraseMedium and ComponentsEMEM—Eagle’s Minimal Essential MediumDMEM/F12—Dulbecco’s Minimal Essential Medium/Ham’s F12CCS—Cosmic Calf SerumFBS—Fetal Bovine SerumFCS—Fetal Calf SerumDifferences between the serum types are unclear as insufficient details are provided by authors to distinguish.

# AX5-88Table AX5-6.7. Genotoxic/Carcinogenic Effects ofLead—Genotoxicity HumanCell Cultures DNA DamageCompoundAssay (Concentration andExposure Time)Cell Type andCulture MediumCo-exposure Effects ReferencePb acetate DNA strand breaks as nucleiodsedimentation (500 μM for 20–25 h)HeLa Cells in AMEM+ 5% FBSNoneSee also TableAX5-6.16Pb acetate alone did not induce single strand breaks.Hartwig et al.(1990)Pb acetate DNA strand breaks as nucleoidsedimentation assay (100 μMfor 30 min–4 h)HeLa Cells inHEPES/glucose bufferButhioninesulfoximine (BSO) todeplete cells of thiolsPb acetate did not induce DNA strand breaks.Snyder andLachmann(1989)Pb chromateDNA adducts (0.4–0.8 μg/cm2for 24 h)Primary Human SmallAirway Cells inClonetics growthmediumNonePb chromate induced Pb inclusion bodies and Cr-DNA adducts andPb-DNA adducts in a concentration-dependent manner.Singh et al.(1999)Pb chromate DNA double strand breaks(0.1–5 μg/cm2for 24 h) byComet assay and H2A.X fociformationWTHBF-6—humanlung cells withhTERT inDMEM/F12 + 15%CCSNonePb chromate induced DNA double strand breaks in a concentrationdependent manner.This study showed the damage was due to chromate and not Pb.Xie et al.(2005)Pb acetate DNA strand breaks and DNAprotein crosslinks and oxidativelesions by comet assay (1–100 μM for 1 h)Primary lymphocytesin RPMI 1640 withoutserumVitamins A (10 μM),C (10 μM), E(25 μM), calciumchloride (100 μM)magnesium chloride(100 μM) or zincchloride (100 μM)Pb acetate induced an increase in DNA single strand breaks at 1 μMthat went down with increasing dose. The highest concentration wassignificantly less than the damage in untreated controls. For doublestrand breaks, all concentrations had more damage than the controls,but there was less damage in the highest concentrations than the twolower ones. Pb only induced a slight increase in the amount of DNA-protein crosslinks at the highest concentration.Co-exposure to magnesium had no effect. Co-exposure to vitamins A,C, and E or zinc exacerbated the DNA single strand break effects at thehighest concentration. Co-exposure to calcium exacerbated the singlestrand break effect at all concentrations.Woźniak andBlasiak (2003)

# AX5-89Table AX5-6.7 (cont’d). Genotoxic/Carcinogenic Effectsof Lead—Genotoxicity Human Cell Cultures DNA DamageCompoundAssay (Concentration andExposure Time)Cell Type andCulture MediumCo-exposure Effects ReferencePb nitrate DNA-protein crosslinks bySDS precipitation(1–10 mM for 6 h)Human Burkitt’slymphoma cells–EBVtransformed in RPMI1640 + 10% FCSNonePb nitrate did not induced DNAprotein crosslinks. Independentsamples were analyzed by 5 different laboratories.Costa et al.(1996)AbbreviationshTERT is the catalytic subunit of human telomerase.Medium and ComponentsAMEM—Alpha Minimal Essential Medium;EMEM—Eagle’s Minimal Essential Medium;DMEM/F12—Dulbecco’s Minimal Essential Medium/Ham’s F12;FBS—Fetal Bovine SerumFCS—Fetal Calf SerumDifferences between the serum types are unclear as insufficient details are provided by authors to distinguish.

# AX5-90Table AX5-6.8. Genotoxic/Carcinogenic Effects of Lead—Genotoxicity Animal Cell Cultures MutagenicityCompoundAssay and DurationCell Type Co-exposureEffectsReferencePb acetateCytotoxicity (1–25 μM for 24 h)Mutagenesis—HPRT (0.5–5 μM for 44 h)V79 in AMEM + 10%FBSNoneSee alsoTable AX5-6.16LC50 = 3 μMPb acetate alone was not mutagenic.Hartwig et al.(1990)Pb acetate—insolubleprecipitate at highdose.Cytotoxicity (0.5–2000 μM for 5 days)Mutagenesis—gpt (0.5–1700 μM for 5 days)G12–CHV79 cellswith 1 copy gpt genein Ham’s F12 + 5%FBSSee also TableAX5-6.17LC50 = 1700 μMPb acetate was mutagenic, but only at toxicconcentration (1700 μM) where precipitate formednot at lower concentrations (500 or 1000 μM).There were no statistical analyses of these data.Roy and Rossman(1992)Pb chlorideCytotoxicity (0.1–1 μM for 1 h)Mutagenicity—gpt assay(0.1–1 μM for 1 h)AS52-CHO-gpt, lackhprt in HBSSfollowed by Ham’sF12 + 5% FBSNoneLC74 = 1 μM (maximum concentration tested)Pb chloride induced a dose-dependent increase inthe number of 6 thioguanine resistant mutants.Did not adjust and compare as previous studies.Ariza et al. (1996)Pb chlorideCytotoxicity (0.1–1 μM for 1 h)Mutagenicity—gpt assay(0.1–1 μM for 1 h)AS52-CHO-gpt, lackhprt in HBSSfollowed by Ham’sF12 + 5% FBSAllopurinol (50 μM)to inhibit xanthineoxidaseLC74 = 1 μM. Allopurinol had no effect oncytotoxicity.Pb chloride was mutagenic (0.8 and 1 μM).Allopurinol reduced mutagenesis.Ariza et al. (1998)Pb chloride Mutagenicity—gpt assay(0.1–1 μM for 1 h)PCR/Southern to analyze mutants forsequenceAS52-CHO-gpt, lackhprt in HBSSfollowed by Ham’sF12 + 5% FBSNonePb chloride (0.1–0.4 μM) caused mostly pointmutations. Higher concentrations (0.5–1 μM)caused more deletions.There were no statistical analyses of these data.Usually examined fewer mutations than control.Ariza and Williams(1999)Pb chromateCytotoxicity (10–100 μM for 24 h)HGPRT assay (10–100 μM for 24 h)V79 CHL–HPRT lowclone in MEM + 10%FCSNTAMutagenesis was assessed with HGPRT assay. Pbchromate was not mutagenic.Co-exposure to NTA caused Pb chromate tobecome mutagenic through increased solubilization.This mutagenic effect was completely attributed tothe Cr(VI) ions.Celotti et al. (1987)Pb chromate Mutagenicity as Sodium/potassium ATPase(ouabain resistance) or 6-thioguanineresistance (25–100 μM for 5 h)C3H10T1/2 cells inEMEM + 10% FBSNonePb chromate was not mutagenic.Patierno et al.(1988) and Patiernoand Landolph(1989) (both paperspresent the samedata)

# AX5-91Table AX5-6.8 (cont’d). Genotoxic/Carcinogenic Effects of Lead—GenotoxicityAnimal Cell Cultures MutagenicityCompoundAssay and DurationCell Type Co-exposureEffectsReferencePb nitratePrecipitate at 1000μM and higher.Cytotoxicity (50–5,000 μM for 5 days)Mutagenesis at HPRT locus(50–2,000 μM for 5 days)V79 CHL–HPRT lowclone in Ham’s F12+10% FBSNoneLC50 = 2950 μMPb nitrate was mutagenic at 500 μM, but there wasno dose response as higher doses less mutagenicthough still 2–4-fold higher. There were nostatistical analyses of these data.Zelikoff et al.(1988)Pb nitrate-no insolubleprecipitateCytotoxicity (0.5–2000 μM for 5 days)Mutagenesis—gpt (0.5–1700 μM for 5 days)G12–CHV79 cellswith 1 copy gpt genein Ham’s F12 + 5%FBSSee also TableAX5-6.17LC 50 = 1500 μMPb nitrate was not mutagenic. There were nostatistical analyses of these data.Roy and Rossman(1992)Pb sulfideCytotoxicity (100–1,000 μM for 24 h)Mutagenicity at HPRT locus(100–1,000 μM for 24 h)V79 CHL–HPRT lowclone in Ham’s F12+10% FBSNoneLC50 = 580 μM; did not increase with longerexposures.Mutagenic at 376 and 563 μM. Not mutageniclower or higher. Suggested cytotoxicity preventedmutagenesis at higher concentrations. There wereno statistical analyses of these data.Zelikoff et al.(1988)AbbreviationsV79 are a Chinese Hamster Lung Cell Line;G12–CHV79 are derived from V79;CHO are a Chinese Hamster Ovary Cell Line ;AS52 are derived from CHO;C3H10T/12 cells are a mouse embryo cell lineMedium and ComponentsAMEM—Alpha Minimal Essential Medium;EMEM—Eagle’s Minimal Essential Medium;HBSS—Hank’s Balanced Salt SolutionFBS—Fetal Bovine SerumFCS—Fetal Calf SerumDifferences between the serum types are unclear as insufficient details are provided by authors to distinguish.

# AX5-92Table AX5-6.9. Genotoxic/Carcinogenic Effects of Lead—Genotoxicity Animal Cell Cultures ClastogenicityCompoundAssay (Concentration andExposure Time)Cell Type and CultureMediumCo-exposure Effects ReferencePb chromate Chromosome Aberrations(0.4–8 μg/cm2for 24 h)Chinese Hamster Ovary AA8cells in AMEM + 10% FBSNonePb chromate induced chromosome damage in aconcentration dependent manner.This study was focused on chromate.Wise et al.(1992)Pb chromate Chromosome Aberrations(0.8–8 μg/cm2for 24 h)Chinese Hamster Ovary AA8cells in AMEM + 10% FBSVitamin C (1 mM for24 h as co-exposure toblock Cr uptake)Pb chromate induced chromosome damage in aconcentration dependent manner.This effect and uptakeof Cr ions were blocked by vitamin C.This study was focused on chromate.Wise et al.(1993)Pb chromate Chromosome Aberrations(0.8 or 8 μg/cm2for 24 h)Chinese Hamster Ovary AA8cells in AMEM + 10% FBSVitamin E (25 μM aspretreatment for 24 h)Pb chromate induced chromosome damage in aconcentration dependent manner. Vitamin E blockedclastogenic activity of Pb chromate, but had no effect onother Pb compounds.This study found that the chromosome damage wasmediated by chromate ions and not Pb ionsWise et al.(1994)Pb chromate Chromosome Aberrations(0.8–8 μg/cm2for 24 h)Chinese Hamster Ovary AA8cells in AMEM + 10% FBSVitamin C (1 mM aspretreatment for 24 h)Vitamin E (25 μM aspretreatment for 24 h)Pb chromate induced chromosome damage in aconcentration dependent manner. Vitamins C and Eblocked clastogenic activity of Pb chromate.This study was focused on chromate.Blankenshipet al. (1997)Pb glutamate Chromosome Aberrations(500–2,000 μM for 24 h)Chinese Hamster Ovary AA8cells in AMEM + 10% FBSVitamin E (25 μM aspretreatment for 24 h)Pb glutamate induced chromosome damage at 1 mM butnot at higher or lower concentrations.Vitamin E did not modify this effect.Wise et al.(1994)Pb nitrate Chromosome Aberrations(500–2,000 μM for 24 h)Insoluble precipitate at allconcentrationsChinese Hamster Ovary AA8cells in AMEM + 10% FBSVitamin E (25 μM aspretreatment for 24 h)Pb nitrate did not induce chromosome damage.Wise et al.(1994)Pb nitrate Chromosome Aberrations(3–30 μM for 2 h +16 h recovery)Chinese Hamster Ovary cellsin EMEM + 10% FBSNone Pb nitrate did not induce chromosome damage. Lin et al.(1994)Pb nitrate Chromosome aberrations(0.05–1 μM for 3–12 h)Chinese Hamster Ovary AA8cells in DMEM +10% NCSCrown ethers tomodify effect throughchelation and uptakePb nitrate did not induce chromosome damage.Cai andArenaz(1998)

# AX5-93Table AX5-6.9 (cont’d). Genotoxic/Carcinogenic Effects of Lead—GenotoxicityAnimal Cell Cultures ClastogenicityCompoundAssay (Concentration andExposure Time)Cell Type and CultureMediumCo-exposure Effects ReferencePb acetateSCE (1–10 μM for 26 h+)V79 in AMEM + 10% FBS NoneSee alsoTable AX5-6.17Pb acetate alone did not induce SCE. Only 25 cells pertreatment analyzed.Hartwiget al. (1990)Pb acetate Micronucleus assay(0.01–10 μM for 18 h)Chinese Hamster V79 cells inDMEM + 10% FCSNone Pb acetate induced an increase in micronuclei thatincreased with concentration and reached a plateau.Two experiments were done andpresented separately as aFigure and a Table. The magnitude of the effects wassmall to modest and statistics were not done.Bonackeret al. (2005)Pb nitrateSCE Formation (500–3,000 μM for24 h)Precipitate at 1000 μM and higher.V79 CHL–HPRT low clone inHam’s F12 +10% FBSNoneNo SCE. Only 30 cells analyzed per treatment.Zelikoffet al. (1988)Pb nitrate Micronucleus formation(3–30 μM for 2 h +16 h recovery)SCE (3–30 μM for 2 h +16 h recovery)CHO cells in EMEM + 10%FBSNone Pb nitrate did not induce micronuclei formationPb nitrate induces a concentration-dependent increase inSCE (3, 10, 30 μM).Lin et al.(1994)Pb nitrateSCE (0.05–1 μM for 3–12 h)CHO AA8 in DMEM +10%NCSCrown ethers tomodify effectthrough chelationand uptakePb nitrate caused a weak concentration-dependentincrease in SCE. These data were not statisticallyanalyzed. The effect was reduced by a crown etherprobably because a similar reduction was seen inspontaneous SCE.Cai andArenaz(1998)

# AX5-94Table AX5-6.9 (cont’d). Genotoxic/Carcinogenic Effects of Lead—GenotoxicityAnimal Cell Cultures ClastogenicityCompoundAssay (Concentration andExposure Time)Cell Type and CultureMediumCo-exposure Effects ReferencePb sulfide SCE Formation(100–1,000 μM for 24 h)V79 CHL–HPRT low clone inHam’s F12 +10% FBSNoneNo SCE. Only 30 cells analyzed per treatment.Zelikoff et al.(1988)AbbreviationsV79 are a Chinese Hamster Lung Cell Line;CHO are a Chinese Hamster Ovary Cell Line ;Medium and ComponentsAMEM—Alpha Minimal Essential Medium;DMEM—Dulbecco’s Minimal Essential Medium;EMEM—Eagle’s Minimal Essential Medium;HBSS—Hank’s Balanced Salt SolutionFBS—Fetal Bovine SerumFCS—Fetal Calf SerumNCS—Newborn Calf SerumDifferences between the serum types are unclear as insufficient details are provided by authors to distinguish.

# AX5-95Table AX5-6.10. Genotoxic/Carcinogenic Effects of Lead—Genotoxicity Animal Cell Cultures DNA DamageCompound Assay (Concentrationand Exposure Time)Cell Type and Culture Medium Co-exposure Effects ReferencePb acetate DNA damage as alkalineelution (exposure time anddose not given)Precipitate at 1000 μM andhigher.V79 CHL–HPRT low clone in Ham’sF12 +10% FBSNoneNo DNA damage (Single strand breaks, DNA-protein crosslinks or DNA-DNA crosslinks).However, the data was not shownZelikoff et al. (1988)Pb acetate DNA strand breaks as nicktranslation (1700 μM for5 days)Or supercoiled relaxation(1000 μM for 5 days)Insoluble precipitate at highdose.G12–CHV79 cells with 1 copy gptgene in Ham’s F12 + 5% FBSSee also TableAX5-6.17Pb acetate did not induce SSB. Pb acetate(1700 μM) did increase nick translation when anexogenous polymerase was added. There were nostatistical analyses of these data.Roy and Rossman(1992)Pb chromate DNA damage as alkalineelution (0.4–8 μg/cm2for24 h plus 24 recovery)Chinese Hamster Ovary AA8 cells inAMEM + 10% FBSNone Pb chromate induced DNA single strand breaks ina concentration dependentmanner, which were allrepaired by 24 h post-treatment.Pb chromate induced DNA protein crosslinks in aconcentration dependentmanner, which persistedat 24 h post-treatment.Pb chromate did not induce DNA-DNAcrosslinks.This study was focused on chromate.Xu et al. (1992)Pb chromate DNA adducts(0.8 or 8 μg/cm2for 24 h)Chinese Hamster Ovary AA8 cells inAMEM + 10% FBSVitamin C (1 mM aspretreatment for 24 h)Vitamin E (25 μM aspretreatment for 24 h)Pb chromate induced DNA adducts in aconcentration dependent manner. Vitamins C andE blocked DNA adducts induced by Pb chromate.This study was focused on chromate.Blankenship et al.(1997)Pb nitrate DNA Protein Crosslinks asSDS precipitation(50–5,000 μM for 4 h)Novikoff ascites hepatoma cells None Pb nitrate induced DNA protein crosslinks in aconcentration dependent manner.Wedrychowski et al.(1986)

# AX5-96Table AX5-6.10 (cont’d). Genotoxic/Carcinogenic Effects ofLead—Genotoxicity AnimalCell Cultures DNA DamageCompound Assay (Concentration andExposure Time)Cell Type and CultureMediumCo-exposure Effects ReferencePb nitrate DNA strand breaks as nicktranslation (1700 μM for 5 days)G12–CHV79 cells with 1 copygpt gene in Ham’s F12 + 5%FBSSee also TableAX5-6.17Pb nitrate (1700 μM) did increasenick translation when anexogenous polymerase was added. There were no statisticalanalyses of these data.Roy and Rossman(1992)AbbreviationsG12–CHV79 are derived from V79;V79 are a Chinese Hamster Lung Cell Line;CHO are a Chinese Hamster Ovary Cell Line ;Medium and ComponentsAMEM—Alpha Minimal Essential Medium;FBS—Fetal Bovine SerumFCS—Fetal Calf SerumDifferences between the serum types are unclear as insufficient details are provided by authors to distinguish.

# AX5-97Table AX5-6.11. Genotoxic/Carcinogenic Effects of Lead—Genotoxicity Non-mammalian CulturesCompound Assay and Concentration Cell Type Co-exposureEffectsReferencePb chromate(and 13pigmentscontaining Pbchromate)Mutation Frequency (50–500 μg/plate)Anchorage Independence for cells isolatedduring morphological transformationNeoplastic Transformation for cellsisolated during morphologicaltransformationSalmonellatyphimurium +/- S9fractionNitrilotriacetic acid(NTA to dissolveinsoluble compounds)and SilicaEncapsulationPb chromate and its related pigments did not inducemutagenicity.A few did when dissolved in NTA.Encapsulation prevented mutagenesis in those thatwere positive when dissolved in NTA.S9 had no effect.Studied as a chromate compound.Connor and Pier(1990)

# AX5-98Table AX5-6.12. Genotoxic/Carcinogenic Effects of Lead—Genotoxicity as it Pertains to Potential Developmental EffectsCompound Assay and ConcentrationSpecies Co-exposureEffectsReferencePb acetate25–400 mg/kg given i.p as single injectionand animals studied after 24 hSperm morphologyMale Swiss Mice—9–12 wks oldNonePb induced sperm head abnormalities at 50–100 mg/kg. A lower dosewas negative and higherdoses were not done.Fahmy (1999)Pb acetate 200 or 400 mg/kg given by gavage dailyfor 5 days5 animals per groupSperm MorphologyMale Swiss Mice—9–12 wks oldCalcium chloride (40 or80 mg/kg by gavagedaily for 3 days given2 wks after Pbexposure)Pb induced sperm abnormalities at 200 and 400mg/kg. A lower dose was negative and higher doseswere not done. Calcium appeared to block this effect.Aboul-Ela (2002)

# AX5-99Table AX5-6.13. Genotoxic/Carcinogenic Effectsof Lead—Genotoxicity as it Pertains toPotential Developmental Effects—ChildrenCompound Exposure Regimen Species Co-exposureEffectsReferencePb chloride Administered in drinking water1.33 g/L for 6 wksMale NMRIMice—9 wks oldCyclophosphamide—120 mg/kg b.w. giveni.p 7 days prior to startof breedingPb did not increase resorptions indicating no dominant lethalmutagenic effect. Pb appeared to have a small, but statisticallyinsignificant reduction in the number of resorptions.Cyclophosphamide reduced live implants in female mice.Kristensen et al.(1993).Pb nitrate12.5–75 mg/kg given i.v. on 9th dayof gestation for 9 days.Mothers and fetuses analyzed onG18.5 animals per groupResorptions, fetal viability, andchromosome damage in the motherand fetus were examined.ICR Swiss WebsterMice—6–8 wks oldNone 12.5–50mg/kghadno effect on resorption or fetal viability.75 mg/kg demonstrated some increased resorption thoughstatistics were not done.No chromosome damage was seenin untreated controls. A lowlevel 1-3 and 2-5 aberrations wereseen in mothers and fetusesrespectively.There was no dose response and no statistical analyses. Datainterpretation is also complicated as too few metaphases wereanalyzed 20–40 total.No descriptions of potential effects on maternal health parametersor fetal weights.No indication of how many animals included in the chromosomalanalysis.Nayak et al.(1989a)Pb nitrate100–200 mg/kg given i.v. on 9thday of gestation for 9 days.Mothers and fetuses analyzed onG18.Group size not given.Resorptions, fetal viability andchromosome damage, SCE andNOR in the mother and fetus wereexamined. Mother–bone marrow;fetus liver or lung3 mothers and fetuses per dose wereanalyzed.ICR Swiss WebsterMice—6–8 wks oldNonePb levels were found in both mother and fetus indicating noproblems crossing the placenta.All doses indicated increased resorption and decreased placentalweights. No effects on fetal weight.Significant increase in SCE in mothers at 150 and 200 mg/kg.No increase in SCE in fetuses.Significant decrease in NOR in both mother and fetuses.No gaps or breaks in mothers or fetuses.Some weak aneuploidy at lowest dose.Some karyotypic chromosome damage was seen. No explanationof how many cells analyzed per animal (3 animals per dose wereanalyzed) as only 20–40 cells were analyzed.There was no dose response and no statistical analyses forchromosome damage. No details on how many animals analyzedfor metaphase damage or howmany cells per animal.Data interpretation is also complicated as too few metaphaseswere analyzed 10–25 for SCE. Not given for CA.No detail on potential maternal toxicity.Nayak et al.(1989b)

# AX5-100Table AX5-6.14. Genotoxic/Carcinogenic Effects of Lead—Epigenetic Effects and Mixture Interactions—AnimalCompound Exposure Regimen Species Co-exposureEffectsReferencePb acetate Administered as an i.p. injection of100 μl/kg.Animals were studied either 24 hafter a daily dose for 3 days or forvarious times (5 min–48 h) after asingle dose.Male Wistar Rats—10 wks oldActinomycin D(0.8 mg/kg)administered i.p. for4 h before a singledose of Pb acetate.Pb acetate induced GST-P, which required the cis element, GPEI(GST-P enhancer I).Actinomycin D blocked the effects indicating that regulation wasat the mRNA level.Pb acetate induced c-jun, which exhibited three peaks of exposureover 48 h.Pb acetate was more potent than Pb nitrate.Suzuki et al.(1996)Pb nitrate Administered as an i.p. injection of100 μmol/kg.Animals were studied either 24 hafter a daily dose for 3 days or forvarious times (5 min–48 h) after asingle dose.Male Wistar Rats—10 wks oldActinomycin D(0.8 mg/kg)administered i.p. for4 h before a singledose of Pb acetate.Pb nitrate induced GST-P, which required the cis element, GPEI(GST-P enhancer I).Actinomycin D blocked the effects indicating that regulation wasthe mRNA level.Pb nitrate induced c-jun, whichexhibited three peaks of exposureover 48 h.Pb nitrate was less potent than Pb acetate.Suzuki et al.(1996)Pb nitrate Administered as an i.p. injection of100 μmol/kg. Some rats werepartially hepatectomized.Animals were studied 48 h afterinjection.Male SpragueDawley ratsPartial Hepatectomy Pb nitrate induced GSH and GST 7-7 activity.Partial hepatectomy did not induce GSH or GST 7-7.Dock (1989)Pb nitrate Administered as an i.v. injection of20, 50, or 100 μmol/kg.Animals were studied 24 h afterinjection.Male Fisher 344rats—7 wks old2-methoxy-4-aminobenzene toinduce P4501A2or3-methylcholanthreneto induce 4501A1Pb nitrate selectively inhibited P4501A2 and its induction by 2-methoxy-4-aminobenzene at the mRNA and protein level in adose-dependent manner.Pb nitrate had minimal effecton P4501A1 and its induction by 3-methyl cholanthrene.Pb nitrate did not affect microsomal activity.Pb nitrate induced GST-P in a dose-dependent manner.Degawa et al.(1993)

# AX5-101Table AX5-6.15. Genotoxic/Carcinogenic Effects of Lead—Epigenetic Effects and Mixture Interactions—HumanCompoundAssay (Concentration andExposure Time)Cell Typeand CultureMedium Co-exposureEffectsReferencePb acetate Tyrosine aminotransferaseexpression and activity(0.3–10 μM for 24–48 h)PKC activity: 10 μM for 48 hH4-IIE-C3—humanhepatoma cellsin DMEM +2.5% FCSDexamethasone(0.1 μM for 16 h),or calcium chloride(10 μM) or genistein(100 μM to block PKCactivity)Pb acetate inhibited glucocorticoid –induction of tyrosineaminotransferase in a time- and dose-dependent manner.Co-treatment with calcium reduced the effects of Pb.Co-treatment with genistein increased the effects of Pb.Pb acetate decreases PKC activity and its translocation from thecytosol to the particulate cellular fraction.Tonner and Heiman(1997)Pb nitrate EROD/MROD activity(10–100 μM for 24 h)NAD(P)H: quinoneoxidoreductase activity(10–100 μM for 24 h)Glutathione-S-transferaseYa activity (10–100 μM for 24 h)Hepa 1c1c7wild type cellsin DMEM +10% FBSTCDD (0.1 nM),3-methyl cholanthrene(0.25 μM), beta-naptflavone (10 μM),benzo(a)pyrene (1 μM)Pb did not affect EROD/MROD activity.Pb reduced CYP1A1 induction by TCDD, 3-methyl cholanthrene,beta-naptflavone, benzo(a)pyrene.Pb increased NAD(P)H: quinone oxidoreductase activityPb increased NAD(P)H: quinone oxidoreductase activity induction byTCDD, 3-methyl cholanthrene, beta-naptflavone, benzo(a)pyrene.10 μM increased Glutathione-S-transferase Ya activity.25 and 100 μM increased Glutathione-S-transferase Ya activity.Pb nitrate did not affect Glutathione-S-transferase Ya induction byTCDD, 3-methyl cholanthrene, beta-naptflavone, benzo(a)pyrene.Korashy andEl-Kadi (2004)Pb nitrate NAD(P)H: quinoneoxidoreductase activity(25 μM for 24 h)Glutathione-S-transferase Yaactivity (25 μM for 24 h)C12- AHR-deficient Hepa1c1c7 cells inDMEM + 10%FBSTCDD (0.1 nM),3-methyl cholanthrene(0.25 μM), beta-naptflavone (10 μM),benzo(a)pyrene (1 μM)Pb nitrate did not increase NAD(P)H: quinone oxidoreductase andGlutathione-S-transferase Ya activityPb increased NAD(P)H: quinone oxidoreductase activity induction byTCDD, 3-methyl cholanthrene, beta-naptflavone, benzo(a)pyrene.Pb did not affect Glutathione-S-transferase Ya induction by TCDD, 3-methyl cholanthrene, beta-naptflavone, benzo(a)pyrene.Korashy andEl Kadi (2004)AbbreviationsMedium and ComponentsDMEM—Dulbecco’s Minimal Essential Medium;FBS—Fetal Bovine SerumFCS—Fetal Calf SerumDifferences between the serum types are unclear as insufficient details are provided by authors to distinguish.

# AX5-102Table AX5-6.16. Genotoxic/Carcinogenic Effectsof Lead—Epigenetic Effects and MixtureInteractions—DNA Repair—HumanCompoundAssay (Concentration andExposure Time)Cell Typeand CultureMedium Co-exposureEffectsReferencePb acetate DNA strand breaks as nucleoidsedimentation (500 μM for20–25 h)HeLa Cells inAMEM + 5%FBSUV (5 J/m2)Pb acetate alone did not induce single strand breaks. UV did inducestrand breaks. Co-exposure of Pb and UV cause DNA strand breaks topersist longer suggesting an inhibition of repair.Hartwig et al.(1990)AbbreviationsMedium and ComponentsAMEM—Alpha Minimal Essential Medium;FBS—Fetal Bovine Serum

# AX5-103Table AX5-6.17. Genotoxic/Carcinogenic Effects of Lead—Epigenetic Effects and MixtureInteractions—DNA Repair—AnimalCompoundAssay (Concentration andExposure Time)Cell Typeand CultureMedium Co-exposureEffectsReferencePb acetateCytotoxicity (0.5–5 μM for 24 h)Mutagenesis—HPRT (0.5–5 μMfor 44h)SCE (1–10 μM for 26 h+)V79 inAMEM + 10%FBSUV (5 J/m2)Pb acetate ( 3 and 5 μM) increasedUV-induced increased cytotoxicitywith no dose response (plateau). There were no statistical analyses ofthese data.Pb acetate (0.5–5 μM) increased UV mutagenicity though with nodose response (plateau). There were no statistical analyses of thesedataPb acetate (1–10 μM) increased UV-induced SCE. Significant atp < 0.01. Only 25 cells per treatment analyzed.Hartwig et al. (1990)Pb acetate Mutagenesis—gpt(0.5–1700 mM for 24 h)DNA strand breaks assupercoiled relaxation(1000 mM for 24 h)G12–CHV79cells with 1copy gpt genein Ham’s F12+ 5% FBSUV (2 J/m2), or MNNG(0.5 μg/L)Pb acetate was co-mutagenic with UV and MNNG increasingfrequency 2-fold.Pb acetate does not increase strand breaks induced by UV.Roy and Rossman(1992)AbbreviationsG12–CHV79 are derived from V79;V79 are a Chinese Hamster Lung Cell Line;Medium and ComponentsAMEM—Alpha Minimal Essential Medium;FBS—Fetal Bovine Serum

# AX5-104Table AX5-6.18. Genotoxic/CarcinogenicEffects of Lead—Mitogenesis—AnimalCompound ExposureRegimen Species Co-exposure Effects ReferencePb acetate Administered Pb acetate (12.5 mg/kg) i.p.Animals studied 24 h after injection.Male B6 Mice None Pb acetate induced TNF-alpha in glial andneuronal cells in the cerebral cortex andsubcortical white matter and on Purkinje cells inthe cerebellum, but did not induced apoptosis inthese areasCheng et al. (2002)Pb nitrate Liver initiation induced by the resistant hepatocytemodelInitiation followed by i.v.injection of Pb nitrate(100 μM/kg ) or partial hepatectomyStudied DNA synthesis (30h after injection) andpreneoplastic nodule formation(5 wks after injection)Male WistarRats—4 per groupPartial Hepatectomy Pb nitrate stimulated DNA synthesis and liver cellproliferationPb nitrate did not induce preneoplastic nodule.Partial hepatectomy did.Columbano et al.(1987)Pb nitrate Liver initiation induced by the resistant hepatocytemodel (diethylnitrosamine followed by 2-acetylaminofluorene plus carbon tetrachloride)Initiation followed by i.v. injection of 4 doses of Pbnitrate (100 μM/kg ) given once every 20 days orpartial hepatectomy, ethylene dibromide, ornafenopineAnimal were evaluated for preneoplastic foci at 75 or155 days after initiation.Male WistarRats—4 per groupDiethylnitrosamine Pb nitrate, partial hepatectomy, ethylenedibromide, or nafenopine all stimulated DNAsynthesis and liver cell proliferationPb nitrate, ethylene dibromide, or nafenopine didnot induce preneoplastic nodule. Partialhepatectomy did.Columbano et al.(1990)Pb nitrate Liver initiation induced by the orotic acid model(diethylnitrosamine plus orotic acid)Initiation followed by i.v.injection of Pb nitrate(100 μM/kg) or partial hepatectomy, or by gavage:ethylene dibromide, or cyproteroneDNA synthesis was examined at various timeintervals (24 h–5 days) after injection.Male WistarRats—4 per groupDiethylnitrosamine Pb nitrate, partial hepatectomy, ethylenedibromide, or cyproterone all stimulated DNAsynthesis within 30 min.Pb nitrate induced DNA synthesis for 5 days.Coni et al. (1992)

# AX5-105Table AX5-6.18 (cont’d). Genotoxic/Carcinogenic Effects of Lead—Mitogenesis—AnimalCompound ExposureRegimen Species Co-exposure Effects ReferencePb nitrate Liver initiation induced by the resistant hepatocytemodel (diethylnitrosamine followed by 2-acetylaminofluorene plus carbon tetrachloride) or thephenobarbital model (diethylnitrosamine plus oroticacid), or the orotic acid model (diethylnitrosamineplus orotic acid)Initiation followed by i.v.injection of Pb nitrate(100 μM/kg ) or partial hepatectomy, or carbontetrachloride by gavageAnimals were studied 6 wks after initiation.Male Wistarrats—4 per groupPartialHepatectomy,carbon tetrachloridePb nitrate, partial hepatectomy, carbontetrachloride all stimulated DNA synthesis andliver cell proliferationPb nitrate, did not induce preneoplastic nodules.Partial hepatectomy and carbon tetrachloride did.Ledda-Columbanoet al. (1992)Pb nitrate Liver initiation induced by the resistant hepatocytemodel (diethylnitrosamine followed by2-acetylaminofluorene plus carbon tetrachloride)Initiation followed by i.v.injection of Pb nitrate(100 μM/kg ) or partial hepatectomy, or by gavage:ethylene dibromide, orcyproterone, or nafenopineAlso tried either 1 or 2 additional i.v. injections of Pbover 3-day intervals.Animals were studied at various intervals (1–6 days)after injectionMale Wistarrats—4 per groupDiethylnitrosamine,2-AAFThis study aimed to determine if mitogens inducenodules at different time points.Pb nitrate, ethylene dibromide, cyproterone, ornafenopine did not induce preneoplastic nodulesat all. Partial hepatectomy did within 3 days.Multiple injections of Pbnitrate did not inducepreneoplastic lesions.Coni et al. (1993)Pb nitrate Administered as i.v. injection of Pb nitrate(100 μM/kg ) or partial hepatectomy, or by gavage:carbon tetrachloride, or ethylene dibromide, orcyproterone, or nafenopineAnimals were studied at various time intervals(0.25–24 h) after injection.Male Wistarrats—4 per groupPartialHepatectomy,carbon tetrachloridePb nitrate, ethylene dibromide, cyproterone, ornafenopine induced c-jun and c-myc but did notinduce c-fos.Partial hepatectomy and carbon tetrachlorideinduced c-jun, c-fos, and c-myc.Coni et al. (1993)Pb nitrate Administered as i.v. injection of Pb nitrate(100 μM/kg) or partial hepatectomy, or nafenopine bygavage.Animals were studied at various time intervals(24–96 h) after injection.Male Wistarrats—4 per group,8 wks oldNonePb nitrate induced a high incidence of polyploidyand binucleated cells. These changes wereirreversible after 2 wks.Many of these cells werethe newly synthesized cells.Partial hepatectomy and carbon tetrachlorideinduced tetraploid and octaploid mononucleatedcells.Melchiorri et al.(1993)Pb nitrate Administered as i.v. injection of Pb nitrate(10 μM/100 g)Studies for apoptosis at 12, 24, 36, 48, 72, 96, 120,168, 336 h after injectionMale Wistarrats—4 rats pergroupNoneLiver weight increaseduntil day 5 then returned tocontrol levels.DNA synthesis peaked at 36 hApoptosis peaked at day 4 and then decreasedgradually.Nakajima et al.(1995)

# AX5-106Table AX5-6.18 (cont’d). Genotoxic/Carcinogenic Effects of Lead—Mitogenesis—AnimalCompound ExposureRegimen Species Co-exposure Effects ReferencePb nitrate Administered as i.v. injection of Pb nitrate(100 μM/kg) or TNF-alpha.Animals were studied at various time intervals(12–48 h) after injection.Male WistarRats—4 pergroup, 5–6 wksoldNonePb nitrate and TNF-alpha induced similarproliferative responses.Shinozuka et al.(1996)Pb nitrate Administered after diethylnitrosamine (200 mg/kggiven i.p) as i.v. injection of Pb nitrate (100 μM/kg )or instead carbon tetrachloride by gavageAnimals were studied at various time intervals(3–21 days) after injection.Male WistarRats—4 per groupCarbontetrachloridePb nitrate induced apoptosis affects both newlysynthesized cells and non-replicative cells.Pb nitrate decreased the number and had no effecton the size of placental glutathione-S-transferaselesions. Carbon tetrachloride substantiallyincreased these lesions both in number and in size.Columbano et al.(1996)Pb nitrate Administered as i.v. injection of Pb nitrate(100 μM/kg ) or partial hepatectomy, or by gavage:carbon tetrachloride, or cyproterone, or nafenopineAnimals were studied at various time intervals(0.5–24 h) after injection.Male WistarRats—8 wks oldPartialHepatectomy,ethylenedibromide,nafenopine, orcyproteronePb nitrate induced NF-kB, TNF-alpha and iNOS,but not AP-1.Carbon tetrachloride induced and activated NF-kB,TNF-alpha iNOS, and AP-1.Nafenopine and cyproteone did not induce oractivate NF-kB,TNF-alpha iNOS, or AP-1.Menegazzi et al.(1997)

# AX5-107Table AX5-6.19. Genotoxic/Carcinogenic Effects of Lead—Mitogenesis Human and Animal Cell Culture StudiesCompoundAssay (Concentration andExposure Time)Cell Type andCulture MediumCo-exposure Effects ReferencePb acetate Cell Proliferation (0.1–100 μM for2–6 days)DNA synthesis (1–100 μM for72 h)Tyrosine aminotransferaseexpression and activity (0.3–10 μMfor 24– 48 h)H4-II-C3—humanhepatoma cells in DMEM+ 2.5% FCSDexamethasone(0.1 μM for 16 h)Pb acetate inhibited cell growth in a time- and dose-dependent manner.Pb acetate inhibited DNA synthesis in a dose-dependentmanner.Pb acetate alone did not inhibit tyrosine aminotransferase.Pb acetate inhibited glucocorticoid–induction of tyrosineaminotransferase in a time- and dose-dependent manner.Heiman andTonner (1995)Pb acetate Cell proliferation (10 μM–1mM for24 h–7 days)REL cells—Rat Epithelialcells in Ham’s F10medium + 10% FBSNone Pb acetate inhibited cell growth at all concentrations for24 h–7 days.Pb acetate did not affect gap junction capacity, which isoften inhibited by tumor promoters.Apostoli et al.(2000)Pb acetate Cell growth (0.01–10 μM for12-72 h)Expression of genes in cytokinepathways (0.01–10 μM for 24 h)U-373MG—humanglioma cell line in DMEM+ 10 or 20% FBSNone Pb acetate did not inhibit or enhance cell growth.Pb acetate enhanced the expression of TNF-alpha, butdecreased interleukin-1 beta, interleukin-6, gamma-aminobutyric acid transaminase, and glutamine synthetaseunder 10% FBS.Pb acetate further enhanced the expression of TNF-alphaunder 20% serum, but had no effect at all on expression ofthe other genes.Liu et al. (2000)Pb acetate Cell proliferation (0.078–320 μMfor 48 h)Apoptosis (1.25–80 μM)Cell cycle analysisRat-1 fibroblasts inEMEM +10% FBSNone Pb acetate inhibited cell growth at 0.635–320 μM.Pb acetate induced apoptosis from 2.5–10 μM.Pb acetate caused GS/M and S-phase arrest.Iavicoli et al.,(2001)Pb acetate DNA synthesis (1–50 μM for 24 h)Expression of genes in mitogenactivated pathways (1–50 μM for5 min–4 h)1321N1–humanastrocytoma cells inDMEM + 0.1% BSANone Pb acetate induced DNA synthesis.Pb acetate induced activation of MAPK, ERK1. ERK2,MEK1 , MEK2, PKC, and p90RSK.Pb acetate did not activate PI3K or p70s6k.Lu et al. (2002)Pb acetate Cell proliferation (1 μM for 24 h)Cell differentiation(1 μM for 48 h)PKC activation (1 μM for 24 h)Primary oligodendrocyteprogenitor cells–inDMEM + 1% FBSNone Pb acetate inhibited basaland growth factor stimulatedgrowth.Pb acetate inhibited cell differentiation in a PHC-dependentmanner.Pb acetate redistributes PKC from the cytosol to themembrane, but did not increase PKC activity.Deng and Poretz(2002)

# AX5-108Table AX5-6.19 (cont’d). Genotoxic/Carcinogenic Effects ofLead—Mitogenesis Human andAnimal Cell Culture StudiesCompoundAssay (Concentration andExposure Time)Cell Type andCulture MediumCo-exposure Effects ReferencePb acetate Expression of TNF-alpha(0.1–10 μM for 24 h)U-373MG—humanglioma cell line inDMEM + 20% FBSNonePb acetate did not induce apoptosis.Pb acetate increased the expression of TNF-alpha in a dose-dependent manner.TNF-alpha was not involved in Pb-induced apoptosis.Cheng et al.(2002)Pb chloride Cell proliferation(10 μM–1mM for 24–48 h)REL cells—Rat Epithelialcells in Ham’s F10medium + 10% FBSNonePb chloride inhibited cell growth at all concentrations for24–48 h.Pb chloride did not affectgap junction capacity, which isoften inhibited by tumor promoters.Apostoli et al.(2000)Pb oxide Cell proliferation(10 μM–1mM for 24 h–7 days)REL cells—Rat Epithelialcells in Ham’s F10medium + 10% FBSNonePb oxide inhibited cell growth at all concentrations for24 h–7 days.Pb oxide did not affect gap junction capacity, which is ofteninhibited by tumor promoters.Apostoli et al.(2000)Pb sulfate Cell proliferation(10 μM–1mM for 24–48 h)REL cells—Rat Epithelialcells in Ham’s F10medium + 10% FBSNonePb sulfate inhibited cell growth at all concentrations for 24–48 h.Pb sulfate did not affect gap junction capacity, which isoften inhibited by tumor promoters.Apostoli et al.(2000)Pb chromate Apoptosis (350 μM for 24 h)Chinese Hamster OvaryAA8 cells in AMEM +10% FBSNonePb chromate induced apoptosis.This study was focused on chromate.Blankenshipet al. (1997)Pb chromate Apoptosis (0.4–2 μg/cm2for 24 h) Primary Human SmallAirway Cells in Cloneticsgrowth mediumNonePb chromate induced apoptosis in a concentration-dependent manner.Singh et al.(1999)Pb chromate Growth Curve (0.5–5 μg/cm224 h) WTHBF-6—human lungcells with hTERT inDMEM/F12 + 10% CCSNone Pbchromateinhibitedcell growth.Holmes et al.(2005)Pb glutamate Growth Curve(250–1,000 μM for 24 h)WTHBF-6—human lungcells with hTERT inDMEM/F12 + 10% CCSNonePb glutamate had no effecton growth.Wise et al. (2005)Pb glutamate Mitotic Index(250–2,000 μM for 24 h)Growth Curve(250–2,000 μM for 24 h)Cell cycle Analysis(250–2,000 μM for 24 h)WTHBF-6—human lungcells with hTERT inDMEM/F12 + 10% CCSNonePb glutamate induced a concentration-dependent increase inintracellular Pb ions.Pb glutamate increased the mitotic index, but either had noeffect or inhibited growthand induced mitotic arrest.Wise et al. (2005)

# AX5-109Table AX5-6.19 (cont’d). Genotoxic/Carcinogenic Effects ofLead—Mitogenesis Human andAnimal Cell Culture StudiesCompoundAssay (Concentration andExposure Time)Cell Type andCulture MediumCo-exposure Effects ReferencePb nitrate Mitotic Index(3–30 μM for 2h +16 h recovery)CHO cells in EMEM +10% FBSNone Lower concentrations (1 and 3 μM) of Pb nitratesignificantly increased the mitotic index. Higherconcentrations (10 and 30 μM) had no effect.Lin et al. (1994)Pb nitrate Mitotic Index(0.05–1 μM for 3–12 h)CHO AA8 in DMEM+10% NCSCrown ethers to modifyeffect through chelationand uptakePb nitrate dramatically reducedthe mitotic index at 1 μMthough this was not statistically analyzed. There was noeffect on mitotic index at lower concentrations. Crownethers had no modifying effect.Cai and Arenaz(1998)Pb nitrate Apoptosis (15–240 μM for 3 h) Rat AlveolarMacrophages in DMEM+ 10% FBSNonePb nitrate induced apoptosis ina dose-dependent manner. Shabani andRabbani (2000)AbbreviationsG12–CHV79 are derived from V79;V79 are a Chinese Hamster Lung Cell Line;hTERT is the catalytic subunit of human telomeraseMedium and ComponentsAMEM—Alpha Minimal Essential Medium;DMEM—Dulbecco’s Minimal Essential Medium;DMEM/F12—Dulbecco’s Minimal Essential Medium/Ham’s F12;EMEM—Eagle’s Minimal Essential Medium;BSA—Bovine Serum AlbuminCCS—Cosmic Calf SerumFBS—Fetal Bovine SerumFCS—Fetal Calf SerumNCS—Newborn Calf SerumDifferences between the serum types are unclear as insufficient details are provided by authors to distinguish.

# AX5-110Table AX5-6.20. Genotoxic/CarcinogenicEffects of Lead—Mitogenesis OtherCompoundAssay (Concentration andExposure Time)Cell Type andCulture MediumCo-exposure Effects ReferencePb acetate Production of reactive oxygenspecies (1 mM for 180 min)Glutathione levels(1 mM for 0–180 min)SH-SY5Y—Humanneuroblastoma cells inDMEM + 7% FCSGlutamate (1 mM)or PKC inhibitor(1 μM)Pb acetate alone did not produce reactive oxygen species. Glutamatealone did.Pb acetate plus glutamate increaseglutamate induced increases inreactive oxygen species.Pb acetate alone did not deplete glutathione. Glutamate alone did.Pb acetate plus glutamate decreased glumate-induced decrease inglutathione.Naarala et al.(1995)Pb acetate Catalase Activity(500–2,000 μM for 24 h)Human ForeskinFibroblasts (Chinese) inDMEM +10% FCS3-aminotriazole(3-AT) (80 mM toinhibit catalase)Pb acetate had no effect on catalase activity.Hwua andYang (1998)Pb acetate Thiol Levels(100 μM for 30 min–4 h)HeLa in HEPES/glucosebufferButhioninesulfoximine(BSO) to depletecells of thiolsPb acetate only lowered thiols marginallySnyder andLachmann(1989)Pb chloride Oxidative Metabolism(0.1–100 μM for 20 h)Phagocytosis (0.1–100 μM for20 h)Macrophages from NMRImice in EMEM (serumnot given)Zymosan andlatex particles assubstrates forphagocytosisPb inhibited oxidative metabolism.Pb inhibited phagocytosis, but onlysignificantly at the highest dose.Hilbertz et al.(1986)Pb chloride Oxidative Enzyme Levels(0.1–1 μM for 1 h)AS52-CHO-gpt, lack hprtin HBSS followed byHam’s F12 + 5% FBSAllopurinol(50 μM) to inhibitxanthine oxidasePb chloride at low concentrations produced H2O2at 1 h and not at24 h. Pb chloride at high concentrations produced no change at 1 hand increased H2O2at 24 h. Allopurinol inhibited H2O2formation athigh Pb concentrations.Pb chloride had no effect on catalase, glutathione peroxidase,glutathione reductase. Pb chloride inhibited glutathione-S-transferase, CuZn-superoxide dismutase, and xanthine oxidase.Ariza et al.(1998)AbbreviationsAS52 are derived from CHO;CHO are a Chinese Hamster Ovary Cell Line;Medium and ComponentsDMEM—Dulbecco’s Minimal Essential Medium;EMEM—Eagle’s Minimal Essential Medium;HBSS—Hank’s Balanced Salt SolutionFBS—Fetal Bovine SerumFCS—Fetal Calf SerumDifferences between the serum types are unclear as insufficient details are provided by authors to distinguish.

# AX5-111 

# ANNEX TABLES AX5-7

# AX5-112Table AX5-7.1. Light Microscopic, Ultrastructural, and Functional ChangesAuthor AnimalSpecies LeadDosage BloodLeadFindingsKhalil-Maneshet al. (1992a)Sprague-Dawleyrat0.5% Pb acetate in drinking waterfor 12 moMax 125.4 μg/dLMean 55 μg/dLHyperfiltration at 3 mo. Decreased filtration at 12 mo.NAG and GST elevated.Nuclear inclusion bodies at all times.Tubulointerstitial scarring from 6 mo.No arterial or arteriolar pathology.Khalil-Maneshet al. (1992b)Sprague-Dawleyrat0.5% Pb discontinued after 6 mo0.01% Pb discontinued after 6 moDMSA 0.5% used in 1/2Hi Pb @12 moDisc 30.4 μg/dLDisc + DMSA 19.1 μg/dLCtrl 3.1 μg/dLLo Pb@12moDisc 6.9 μg/dLDMSA5.5 μg/dLHigh Pb:Nuclear inclusion bodies prominent.Tubulointerstitialdisease severe but less than 12 mocontinuous DMSA caused reduction in nuclear inclusionbodies and tubuloint decrease, and an increase in GFR.Low Pb:Neg pathology and increase in GFR with DMSAKhalil-Maneshet al. (1993a)Sprague-Dawleyrat0.01% Pb acetate for 12 mo Max 29.4 μg/dLRange 9–34 μg/dLGFR increased at 1 and 3 mo.NAG increased but GST normal.Pathology neg except at 12 mo—mild tubular atrophy andinterstitial fibrosis seen.Sanchez-Fructuoso et al.(2002a)Wistar rat 500 ppm (0.05%) Pb acetate for2 mo, then EDTAMax 52.9 μg/dLDay 90: 33.2Day 137: 22.8Ctrl: 5.90 μg/dLRats given Pb to day 90, then treated with EDTA or untreatedto day 137.Marked decrease in kidney, liver, and brain Pb with EDTA butno change in femur PbSanchez-Fructuoso et al.(2002b)Wistar rat 500 ppm (0.05%) Pb acetate for2 mo, then EDTAMax 52.9 μg/dLDay 90: 33.2Day 137: 22.8Ctrl: 5.90 μg/dLHypertrophy and vacuolization ofmedium and small arteries,mucoid edema and muscular hypertrophy of arterioles, includebodies and fibrosis.EDTA slowed progression.Papaioannou et al.(1998)Dogs12 mg Pb acetate i.p.H10—Pb includes bodies intracytoplasmically in mesothelial andgiant cells of peritoneum and in interstitial connective tissuecells of kidney. None in prox tubules of kidney.

# AX5-113Table AX5-7.1 (cont’d). Light Microscopic,Ultrastructural, and Functional ChangesAuthor AnimalSpecies LeadDosage BloodLeadFindingsVyskocil et al.(1989)Wistar rat 0.5%, 1%, and 2% Pb acetate for2–3 mo0.5%–105 μg/dL1%–196 μg/dL2%–320 μg/dL0.5%—no morphologic or functional changes.1%—Incr inβ-2 microglobulin excretion.2%—Incr inβ2micr, glucose, protein, lysozyme, and LDH.Hyperplasia and include bodies of prox tubules seen in both1% and 2%.Vyskocil et al.(1995)Wistar rat 1% or 0.1% Pb acetate for 2–4 mo 1%–173 μg/dL0.1%–37.6 μg/dL1% caused increase inβ-2 microglobulin excretion and injuryto proximal tubule.0.1% caused no changes.Vyskocil andCizkova (1996)Wistar rats Unleaded petrol vapor (4mg/m3)8 hrs/day for 60 days—Β-2 microglobulin excretion increased at 60 days.Sanchez et al.(2001)Sprague-Dawleyrat0.06% Pb acetate for 4 mo13.9 μg/dL vs. <0.5 μg/dLin ctrlDecrease in expression of laminin-1 and increase in expressionof fibronectin in kidneys.HerakKramberger et al.(2001)Rat brush bordermembranes500 μM Pb—58% loss of sealed brush border membrane vesicles. Lowerloss of sealed basolateral membrane vesicles.Fujiwara et al.(1995),Kaji et al. (1995b)Bovine culturedvascular smoothmuscle andendothelial cells0.5–10 μM Pb nitrate—Stimulated proliferation insmooth muscle cells. Reducedproliferation in endothelialcells No leakage of LDH.

# AX5-114Table AX5-7.2. Lead and Free RadicalsAuthor AnimalSpecies LeadDosage BloodLeadFindingsPereira et al.(1992)Rats ALA-treated (40 mg/kg every2 days for 15 days)—Fatigued earlier than controls.Increase of CuZn SOD in brain, muscle and liver.Somashekaraiahet al. (1992)Chick embryos 1.25 and 2.5 momol/kg of Pb acetate—Lipoperoxides maximal at 9 hrs and returned to normal at72 hrs.GSH depleted. GST, SOD and catalase increased in liver,brain and heart at 72 hrs.Bondy and Guo(1996)Sprague-Dawleyrat cerebralsynaptosomes0.5 mM Pb acetate—Generation of ROS not increased by Pb alone but increasedwhen 50 μM iron sulfate added.Blazka et al.(1994)Mouse brainmicrovascularendothelial cellculture10, 100, and 1,000 nM Pb acetate—Constitutive production of nitrite, but not inducible, decreasedby Pb. Extracellular calcium abolishes this effect.Quinn and Harris(1995)Rat cerebellumhomogenates17–80 nM Pb nitrate—Constitutive NOS activity inhibited 50% by 17 nM Pb and100% by 80 nM Pb. Reversed byincreasing Ca concentration.Ercal et al. (1996) C57BL/6 mice1300 ppm Pb acetate for 5 wks,Nac, 5.5 mmol/kg, or DMSA,1 mmol/kg, given in 6th week.36.5 μg/dL in Pb-treated;13.7 μg/dL in Pb +DMSA-treatedLiver and brain GSH depleted by Pb and MDA increased.Both were restored by either DMSA or NAC. However,DMSA reduced blood, liver, and brain Pb levels while NACdid not.Vaziri and coworkers (1997–2004)Sprague-DawleyratsSee Section 5.5 for details Variable See Section 5.5 for details.Farmand et al.(2005)Sprague-Dawleyrats100 ppm Pb acetate for 3 mo—CuZnSOD activity increased in kidney. CuZnSOD activityincreased in aorta whereasprotein abundance unchanged.Guanylate cyclase protein abundance in aorta decreased.Gurer et al.(1999)Fischer 344 rats 1100 ppm Pb acetate for 5 wks,Captopril for 6th wk24.6μg/dL in Pb-treated.23.8 μg/dL in Pb +Captopril-treatedMDA in liver, brain, and kidney increased by Pb. GSHdecreased. Captopril reversed these findings.

# AX5-115Table AX5-7.2 (cont’d). Lead and Free RadicalsAuthor AnimalSpecies LeadDosage BloodLeadFindingsAcharya andAcharya (1997)Swiss mice200 mg/kg Pb acetate i.p.H1—MDA-TBA increasedH4 in liver, brain, kidney, and testis byend of 1st wk and persisted for 4 wks.Upasani et al.(2001)Rats 100 ppm Pb acetate for 30 days,Groups given vit C, vit E, or algae—MDA, conj dienes, and H2O2increased in liver, lung, andkidney by Pb. Treatment with vitC, vit E, or Blue Green algaereversed these findings.Pande et al.(2001)Wistar ratsPb nitrate 50 mg/kg i.p.H5Pb + DMSA,MiADMSA,NAC,DMSA + NAC,DMSA +MiADMSA—DMSA most effective in blocking inhib of ALAD, elev ofZPP, and inhib of GSH.Combined DMSA+NAC mosteffective when given during or post-exposure.Pande and Flora(2002)Wistar rats2000 ppm Pb acetateH4 wks,DMSA,MiADMSA, DMSA +LA,MiADMSA + LAH5 days—Pb caused decrease in ALAD, GSH, and increase ZPP. Lipoicacid (LA) did not chelate Pb in contrast to DMSA, but bothagents increased ALAD and GSH.Flora et al. (2003) Wistar rats1000 ppm Pb acetateH3 mo,DMSA or MiADMSA + vit C orvit EH5 days13.3 μg/dLPb Rx3 μg/dL DMSA Rx<1μg/dL DMSA+ vit EBoth thiol chelators and 2 vitamins increased ALAD. GSHincrease only after thiol chelators. Vitamin E or C with thiolchelators reduced blood Pb further.Saxena and Flora(2004)Wistar rats2000 ppm Pb acetateH6 wks,CaNa2EDTA + DMPS orMiADMSAH5 days15.1μg/dLPb Rx9.8 μg/dL EDTA Rx6 μg/dL EDTA +MiADMSPb caused inhib of ALAD and GSH and depl of ALAD inkidney, ALAS in liver, GSH in brain, increase in brain TBARSand GST. Combined Rx with CaNa2EDTA and MiADMSAmost effective in reducing oxidative stress and tissue Pbburden.Tandon et al.(2002)Rats2000 ppm Pb acetateH9 wks,DMSA, MiADMSA, or NAC orcomboH6 days—Pb raised MDA, inhibited ALAD, increased catalase, anddepleted GSH. DMSA plusNAC was most effective inreversing these changes.

# AX5-116Table AX5-7.2 (cont’d). Lead and Free RadicalsAuthor AnimalSpecies LeadDosage BloodLeadFindingsSivaprasad et al.(2002)Wistar rats2000 ppm Pb acetateH5 wksLA and DMSA during 6th week.—Pb caused red in kidney GGTand NAG, decline in GSH,catalase, SOD, GPx and Glut reductase, and increased MDA.Lipoic acid+DMSA restored these changes.Senapati et al.(2000)Rats 1% sol of 5 mg/kgPb acetateH43 daysThiamine 25 mg/kg—Thiamine reduced Pb content and MDA levels of both liverand kidney and improved pathology.Patra et al. (2001) IVRI 2CQ rats 1 mg/kg Pb acetate for 4 wksVit E, vit C or methionine in 5th wk.Vit E + EDTA.6.8 μg/dL Pb-Rx6.3 μg/dLPb, vit E +EDTAPb in liver, kidney and brain reduced by vit E + EDTAtreatment. MDA increased by Pbin all 3 organs but decreasedby vit E + EDTA.McGowan andDonaldson (1987)Chicks2000 ppm Pb acetateH3 wks—GSH, non-protein SH, lysine and methionine increased in liverand non-prot SH, glycine, cysteine and cystathionine inkidney. Cysteine reduced in plasma.

# AX5-117Table AX5-7.3. Chelation with DMSAAuthor AnimalSpecies LeadDosage BloodLeadFindingsCory-Slechta(1988)Rats 50 ppm Pb acetate for 3–4 mo 20 μg/dL-Pb1 μg/dL-Pb+25 mg/kgDMSADMSA 25–50 mg/kg i.p. for 1–5 days mobilized Pb fromblood, brain, kidney and liver, but not femur.Pappas et al.(1995)Sprague-Dawleyrats550–1100 ppm Pb acetate for35 days52 μg/dL @ 550 ppm Pb65 μg/dL @ 1100 ppm PbDMSA @16–240 mg/kg/d p.o. for 21 days given with andwithout concurrent Pb exposure.Rats showed dose-relatedreduction in Pb content of blood, brain, femur, kidney, andliver with or without concur Pb.Smith and Flegal(1992)Wistar rats206Pb 210 ng/mL for 1.5 daysDMSA 20 mg/kg i.p.5.1 ng/g-ctrl3.0 ng/g-DMSARats on low Pb diet given DMSAdecreased soft tissue but notskeletal Pb. Pb redistributed to skeleton.Varnai et al.(2001)Wistar rats(suckling)2 mg/kg/d for 8 daysDMSA 0.5 mmol/kg 6x/d on d1-3and 6–8—DMSA reduced Pb concentration in carcass, liver, kidneys, andbrain by ~50%.

# AX5-118Table AX5-7.4. Effect ofChelator CombinationsAuthor AnimalSpecies LeadDosage BloodLeadFindingsFlora et al.(2004)Wistar rats 1000 ppm Pb acetate for 4 mo 46 μg/dL-Pb12.8 μg/dL-combined Rx5 days Rx with DMSA. CaNa2EDTA, or DMSA +CaNa2EDTA. Comb Rx resulted in increased ALAD anddecreased Pb in blood, liver, brain, and femur.Jones et al.(1994)Mice 10 i.p. injections of Pb acetate,5.0 mg/kg—Mice Rx’ed with DMSA, CaNa2EDTA, ZnNa2EDTA, orZnNa3DTPA 1.0 mmol/kg/d 4–8 days. CaNa2EDTA mosteffective in removing brain Pb; DMSA in removing kidneyand bone Pb.Kostial et al.(1999)Wistar rats(suckling)5 mg Pb/kg i.p.H1Chel agents days 2 and 3—EDTA, DMSA, racemic DMSA, EDTA + DMSA, EDTA +rac DMSA given. EDTA reducedZn in carcass and liver; racDMSA reduced Zn in kidneys. DMSA reduced Pb w/oaffecting Zn.Flora et al.(2004)Wistar rats1000 ppm Pb acetateH2 mo—DMSA, taurine or DMSA + taurine given for 5 days. Bothtaurine and DMSA restored GSH.Comb of DMSA + taurineincreased RBC SOD and decreased TBARS, while mosteffectively depleting blood, liver, and brain Pb.Sivaprasad et al.(2004)Wistar rats2000 ppm Pb acetateH5 wks—DMSA, lipoic acid or combination given during 6th week.Renal enzymes, kidney Pb and renal ALAD restored bycombined Rx.Malvezzi et al.(2001)Wistar rats750 ppm Pb acetateH70 daysDMSA, arginine, DMSA + arg orH2OH30 days67.8 μg/dL to 11.2 μg/dLin H2O Rx’ed to 6.1μg/dL in DMSA + argPb increased BP and Pb levelsin blood, liver, femur, kidney,and aorta. DMSA + L-arginine most effective in lowering BPand mobilizing Pb from tissues.Tandon et al.(1997)Rats 1000 ppm Pb acetate for 7 wks.DithiocarbamateH4 days105.3 μg/dL in Pb86 μg/dL indithiocarbamate.Two dithiocarbamates were compared: N-benzyl-D-glucamineand N-(4-methoxybenzyl)-D-glucamine. They were onlypartially effective in restoring ALAD, reducing liver andkidney, but not brain Pb. They depleted Zn, Cu, and Ca.

# AX5-119Table AX5-7.5. Effect ofOther Metals on LeadAuthor AnimalSpecies LeadDosage BloodLeadFindingsMaldonado-Vegaet al. (1996)Wistar rats(pregnant andnonpregnant)100 ppm Pb acetate for 144–158 days5.2 (ctrl) to 27.3 μg/dL inPb-exposed8 (non-preg) to 17 μg/dLin rats exposed onlyduring lactationPb administered to period before lactation (144 days) or tomid-lactation (158 days).Pb in blood, kidney, liver, and boneincreased.ALAD decreased and FEP incr. Lactation increased.Blood Pb from 24.7 to 31.2 μg/dL and decreased bone Pb from83.4 to 65.2 nmol/g.Olivi et al. (2002) MDCK caninekidney cells1 μM—In response to agonists ADP or bradykinin levels ofintracellular Ca increased 3-fold and 2-fold. Pb inhibited theresponse.Bogden et al.(1991)Wistar rats 0,1,100 ppm Pb for 31 wks0.2% or 4.0% Ca diet1.9 to 39.1 μg/dL on lowCa diet and 2.0 to 53.3μg/dL on high Ca dietAt 100 ppm Pb high Ca diet produced higher BP and morerenal cancers than low Ca diet and higher levels of Pb in brain,liver, bone, heart, and testis but lower levels in kidney. SerumCa on high Ca diet was 13.2 mg/dL.Skoczyńska et al.(1994)Buffalo rats Pb 70 mg/kg 2x/wk for 7 wks Cd20 mg/kg 1x/wk for 7 wks.All intragastric.5.1 to 29.6 μg/dL in Pb-exposed. 37.4 μg/dL inPb + CdSimultaneous Pb and Cd administration increased blood Pb butdecreased Pb in liver and kidneys as compared to Pbadministration alone.Othman andEl-Missiry (1998)Albino ratsPb acetate 100 momol/kg I.M.H1Se 10 momol/kg I.M. 2 hrs beforePb—Sodium selenite (Se is a well-known anti-oxidant) preventedlipid peroxidation (TBARS) and reduction in GSH caused byPb. SOD and glut reductase also normalized.Tandon et al.(1992)Albino ratsPb acetate 10 mg/kg/d p.o.H6 wks.EDTA or DTPA given for 5 days w/or w/o Se17 to 138 μg/dL after Pb58 μg/dL after EDTA.50 μg/dL after EDTA + SeSelenium had no additional benefit over chelators except forhigher ALAD and lower ZPP in blood, lower Pb in liver andkidney.Flora et al. (1989) Albino ratsPb acetate 10 mg/kg/d p.o.H6 wksThiamine, Zn or thiamine + ZnH6wks6.2 to 120.9 μg/dL afterPb44.1 μg/dL after thiamine+ ZnThiamine given as 25 mg/kg/d and Zn sulfate as 25 mg/kg/d.ALAD restored by combined Rx. Liver and kidney Pbaffected to a minor degree but brain Pb not affected.Flora et al. (1994) Wistar albino ratsPb acetate 10 mg/kg/dH56 daysp.o. EDTA or EDTA + ZnH5 daysp.o.4.6 to 43.0 μg/dL in Pb.22.5 μg/dL in EDTA16.5 μg/dL in EDTA +Zn.CaNa2 EDTA given as 0.3 mmol/kg/d i.p. and Zn sulfate as 10or 50 mg/kg/d. ALAD partially restored after EDTA + Zn butnot after EDTA. EDTA reduced Pb in bone, kidney, and liverbut not in brain. Zn conc increased in blood, kidney, and brainby 50 mg Zn dosage.

# AX5-120Table AX5-7.5 (cont’d). Effectof Other Metals on LeadAuthor AnimalSpecies LeadDosage BloodLeadFindingsSatija and Vij(1995)Albino ratsPb acetate 20 mg/kg/d i.p.H3 daysZn acetate 5 mg/kg/d i.p.H3 days—Pb caused a decrease in Hgb, ALAD, and uroporphyrinogen Isynthetase, partially restored by Zn. Total SH and non-proteinSH reduced by Pb, partially restored by Zn.Munoz et al.(1993)Wistar ratsPb acetate 60 ppmH90 days,Zn or methionine givensimultaneously<60 μg/dL-PbSAM reduces to averageof 7.3 μg/dLS-adenosyl-l-methionine (SAM) reduces blood Pb anduroporphyrinogen I synthetase. RBC ALAD reduced by Pband 2 Rx. Liver ALAD decreased by Pb, increased by SAM.Tandon et al.(1997)Albino ratsPb acetate 10 mg/kg/dH8 wks p.o.Ethanol, Zn and lysineH8 wks1.8 to 47.2 μg/dL w Pb.Decreased to 34.2 μg/dLw Zn + lysine.Ethanol reduced blood but notliver GSH beyond Pb alone.Zn + lysine partially restored ALAD, increased GSH, andreduced Pb in kidney.Hashmi et al.(1989)RatsPb acetate 1000 ppmH6 wksFe-deficient or norm diet—Fe deficiency increased Pb in liver, kidney, spleen butincreased femur Pb at 3 wks and decreased femur Pb at 6 wks.Tandon et al.(1993)RatsPb acetate 400 momol/kg i.p.H1Fe deficient and Fe-sufficient dietsH6 wk—Pb induced hepatic metallothionein (MT). Fe deficient diet +Pb restored kidney and intestinal MT from low levels causedby Fe def. Pb in liver and kidney enhanced by Fe defCrowe andMorgan (1996)Wistar rat pupsPb acetate 2000 ppmH15, 21, and63 daysFe def and Fe suff dietsAt 63 days Fe def410 μg/dLFe suff rats 170 μg/dLFe deficiency increased blood and kidney Pb but did not affectbrain or liver Pb. Fe levels in brain and kidney wereunaffected by Pb intoxication.Singh et al.(1991)Pregnant femalealbino ratsPb acetate 250–2000 ppm from15–20 days of gestation.At 2000 ppm Pb, Fe def220 μg/dLFe suff 160 μg/dLFe def and Fe suff diets givento dams for 30 days. Fetusesremoved on 21st day. At 2000 ppm, Pb in maternal blood,placenta, and fetus higher in Fedef. Max pathol changes infetal kidney.Shakoor et al.(2000)Albino ratsPb acetate 125 mg/kgH90 daysAl chloride 50–100 mg/kgH90 days—Plasma creat 1.88 mg/dL in Pb-Rx’ed; 1.34 mg/dL inPb + Al-Rx’ed Kidney Pb increased from 5.4 in ctrl to220 μg/g in Pb-Rx’ed, decreased to 98.9 μg/g in Pb + Al.

# AX5-121 

# ANNEX TABLES AX5-8

# AX5-122Table AX5-8.1. Bone Growth in Lead-exposed AnimalsCompoundDose/ConcentrationDuration ExposureRouteSpecies Effects Blood Level ReferencePb acetate41.7 mg Pb/l83.3 mg Pb/l166.6 mg Pb/l12 to 16 wksDrinking waterRat Pb level in bone of control animalsWk 0 = 1.3 ± 0.83 μg Pb/g; Wk 4 = 1.2 ± 0.99 μg Pb/g;Wk 8 = 1.3 ± 1.08 μg Pb/g; Wk 12 = 0.8 ± 0.13 μg Pb/g;Wk 16 = 1.3 ± 0.95 μg Pb/gPb level in bone of animals receiving 41.7 mg Pb/lWk 0 = 1.0 ± 0.50 μg Pb/g; Wk 4 = 5.9* ± 1.76 μg Pb/g;Wk 8 = 2.9* ± 1.15 μg Pb/g; Wk 12 = 6.2* ± 1.01 μg Pb/g;Wk 16 = 6.0* ± 0.75 μg Pb/gPb level in bone of animals receiving 83.3 mg Pb/lWk 0 = 2.0 ± 0.97 μg Pb/g; Wk 4 = 11.7* ± 3.56 μg Pb/g;Wk 8 = 8.8* ± 3.37 μg Pb/g; Wk 12 = 14.3* ± 4.29 μg Pb/gPb level in bone of animals receiving 166.6 mg Pb/lWk 0 = 0.9 ± 0.23 μg Pb/g; Wk 4 = 17.0* ± 3.89 μg Pb/g;Wk 8 = 35.7* ± 3.64 μg Pb/g; Wk 12 = 21.7* ± 5.11 μg Pb/g;*significantly higher than controlanimals at corresponding time pointNot givenHaćand Krechniak(1996)Pb aerosol77, 249, or 1546 μg/m3for 50 to 70 daysInhalationRat 16.9 ± 6.6 μg Pb/g bone taken up in animals exposed to 77 μg/m3for70 days versus 0.2 ± 0.2 μg Pb/g in control animals;15.9 ± 4.3 μg Pb/g bone in rats exposed to 249 μg/m3for 50 days;158 ± 21 μg Pb/g bone in rats exposed to 1546 μg/m3for 50 daysControl: 2.6 μg/dL77 μg/m3: 11.5 μg/dL249 μg/m3: 24.1 μg/dL1546 μg/m3: 61.2 μg/dLGrobler et al. (1991)Pb acetate250 ppm or 1000 ppm7 wks to females priorto mating, continuingthrough gestation andlactationDrinking waterRat Offspring body weight was depressed relative to controls duringsuckling (Day 11) and after weaning (Day 24) in high dose andcontinuously Pb-exposed groups.Continuous Pb exposure caused a greater decrease in offspring bodyweight than Pb exposure only prior to or after parturition.Decreased tail length growth suggested possible effects of Pb on tailvertebral bone growth.Dams prior to mating:Control = 2.7 ± 0.6 μg/dL250 ppm = 39.9 ± 3.5 μg/dL1000 ppm = 73.5 ± 9.3 μg/dLHamilton andO’Flaherty (1994)

# AX5-123Table AX5-8.1 (cont’d). Bone Growth in Lead-exposed AnimalsCompoundDose/ConcentrationDuration ExposureRouteSpecies Effects Blood Level ReferencePb acetateHi Pb animals 5000ppm for 6 mo, reducedto 1000 ppm;Lo Pb animals 100 ppmDrinking WaterRat In male rats exposed to 100 ppm Pb in drinking water and a lowcalcium diet for up to one yr, bonedensity was significantly decreasedafter 12 mo, while rats exposed to 5000 ppm Pb had significantlydecreased bone density after 3 mo. Pb content of femurs wassignificantly elevated over the content of control rats at all time points(1, 3, 6, 9, 12 mo). Trabecular bone from the low dose animals wassignificantly decreased from 3 mo forward.Low Pb (μg%):1 moControl = 2 ± 1; Exp = 19 ± 10*3 moControl = 2 ± 1; Exp = 29 ± 4*6 moControl = 3 ± 1; Exp = 18 ± 2*9 moControl = 1 ± 1; Exp = 17 ± 3*12 moControl = 3 ± 1; Exp = 21 ± 3*Hi Pb (μg%):1 moControl = 3 ± 1; Exp = 45 ± 13*3 moControl = 3 ± 1; Exp = 90 ± 15*6 moControl = 4 ± 1; Exp = 126 ± 10*9 moControl = 4 ± 1; Exp = 80 ± 39*12 moControl = 3 ± 1; Exp = 59 ± 18**p < 0.001Gruber et al. (1997)Pb acetate17 mg per kg of feed50 daysIn dietRat No differences in the length of the femurs, but the mean length of the5th lumbar vertebra was significantly decreased. The mean length ofthe femur growth plate cartilage was also significantly decreased in Pb-exposed animals.Not given González-Riola et al.(1997)Pb acetate17 mg per kg of feed50 daysIn dietRat No differences in the length of the femurs, but the mean length of the5th lumbar vertebra was significantly decreased. The mean length ofthe femur growth plate cartilage was also significantly decreased in Pb-exposed animals.Not given Escribano et al. (1997)

# AX5-124Table AX5-8.1 (cont’d). Bone Growth in Lead-exposed AnimalsCompoundDose/ConcentrationDuration ExposureRoute Species Effects Blood Level ReferencePb acetate0.6%GD 5 to Adulthood(various)In drinking waterRat Early bone growth was significantly depressed in a dose-dependentfashion in pups of Pb-exposed pups, with growth suppression in maleoffspring considerably greater than females. Significant decreases inplasma insulin-like growth factor and plasma sex steroids andincreased pituitary growth hormone were also observed.Groups:DDW = Dams and pups received distilled deionized water entire studyAc/Ac = Dams and pups received acetic acid solution entire studyPreg = Dams received 0.6% Pb water from GD 5 to parturitionLact = Dams received 0.6%Pb water during lactation onlyP + L = Dams received 0.6% Pb water from GD 5 through lactationPostnatal = Dams and pups received0.6% Pb water from parturitionthrough adulthoodPb/Pb = Dams and pups received 0.6% Pb water from GD 5 throughadulthoodWhole blood Pb (μg/dL) inmale/female offspring at ageDay 85:DDW = 5.5 ± 2.0/6.8 ± 1.5;Ac/Ac = 1.9 ± 0.2/1.4 ± 0.3;Preg = 9.1 ± 0.7*/11.6 ± 4.6*;Lact = 3.3 ± 0.4/3.4 ± 0.8;P + L = 16.1 ± 2.3*/10.4 ± 1.8*;Postnatal = 226.0 ± 29.0*/292.0 ±53.0*;Pb/Pb = 316.0 ±53.0*/264.0 ±21.0**p < 0.05 compared to Ac/Acgroup.Ronis et al. (1998a)Pb acetate0.05% to 0.45%GD 5 through sacrificeof pups at 21, 35, 55,and 85 daysIn drinking waterRat Early bone growth was significantly depressed in a dose-dependentfashion in pups of all Pb-exposed groups, with growth suppression inmale offspring considerably greater than females. Significantdecreases in plasma insulin-like growth factor and plasma sex steroidsand increased pituitary growthhormone were also observed.Between age 57 and 85 days growth rates were similar in control andPb-exposed pups, suggesting exposureat critical growthperiods suchas puberty and gender may account fordifferences in growth reportedby various investigators.Offspring:0.05% Pb = 49 ± 6 μg/dL; 0.15%Pb = 126 ± 16 μg/dL; 0.45% Pb =263 ± 28 μg/dLRonis et al. (1998b)Pb nitrate0.02% (125 ppm)GD5 to 1 day beforesacrificeIn drinking waterRat Exposure to 0.02% Pb nitrate (125ppm Pb) did not significantly affectgrowth, though males weighed significantly less than females.Rat Pups5 days old: 43.3 ± 2.7 μg/dL49 days old: 18.9 ± 0.7 μg/dL(females: 19.94 ± 0.8 μg/dL;males: 17.00 ± 1.1 μg/dL)Camoratto et al. (1993)

# AX5-125Table AX5-8.1 (cont’d). Bone Growth in Lead-exposed AnimalsCompoundDose/ConcentrationDuration ExposureRoute SpeciesEffectsBloodLevel ReferencePb acetate0.15% or 0.45%GD 4 until Day 55In drinking waterRat A dose-dependent decrease in loadto failure in tibia from Pb-exposed(0.15% and 0.45% Pb acetate in drinking water) male pups only.Hormone treatments (L-dopa, testosterone or dihydrotestosterone inmales, or estradiol in females) failed to attenuate Pb deficits during thepubertal period. Distraction osteogenesis experiments performed afterstabilization of endocrine parameters (at 100 days of age) founddecreased new endosteal bone formation and gap x-ray density in thedistraction gaps of Pb-exposed animals.Offspring:0.15% Pb = 67–192 μg/dL;0.45% Pb = 120–388 μg/dLRonis et al. (2001)Pb acetate1000 ppm22–26 daysIn drinking waterRat Pb disrupted mineralization during growth in demineralized bonematrix implanted subcutaneously into male rats. In the matrix thatcontained 200 micrograms Pb/g ofplaque tissue, alkaline phosphataseactivity and cartilage mineralization wereabsent, though calciumdeposition was enhanced. Separate experiments found enhancedcalcification and decreased alkaline phosphatase activity in ratsimplanted with a control (no Pb) matrix and given 1000 ppm Pb indrinking water for 26 days.Blood Pb (μg/dL)Control:Implantation Day 0 = 1.3 ± 0.6;Day 8 = 2.2 ± 0.9; Day 12 = 2.1 ±0.7.Pb added to matrix:Implantation Day 0 = 1.5 ± 0.8;Day 8 = 5.7 ± 0.8a,b; Day 12 = 9.5± 0.5a,b.Pb in drinking water:Implantation Day 0 = 129.8 ±6.7a; Day 8 = 100.6 ± 6.8a,bDay 12 = 96.4 ± 5.3a,b.aSignificant (p#0.05) differencefrom control.bSignificance (p#0.05)difference from correspondingvalue at implantation (Day 0).Hamilton andO’Flaherty (1995)AbbreviationsMg—milligramμg—microgramppm—parts per millionGD—gestational dayPb—leadg—gramμg%—microgram percentl—literm3 -—cubic meterExp—experimental groupwk—weekdL—deciliter%—percent

# AX5-126Table AX5-8.2. Regulation of Bone Cell Function in Animals—Systemic Effects of LeadCompoundDose/ConcentrationDuration ExposureRouteSpecies Effects Blood Level ReferencePb acetate30 mg/kgSingle i.v. injectionRat Groups of male rats were killed 0.5, 5, 15, and 30 min and 1, 2, 6, and 12 h after the singlePb injection. Serum calcium and phosphoruslevels both initially increased after Pbinjection with serum phosphorus reaching a maximum value (13.5 mg%) after 30 min andcalcium (17 mg%) after 1 h. Calcium andphosphorus levels decreased after 1 h andreturned to baseline levels after 12 h.Not given Kato et al. (1977)Ingestion of 0.82% Pb in male rats fed either a low phosphorus or low calcium diet reducedplasma levels of 1,25-(OH)2CC, while Pb had no effect in rats fed either a high calcium dietor a normal phosphorus diet.Effect of Pb on serum 1,25-(OH)2CC levels in rats fed low P or normal P dietDietary Phosphorus0.1%0.1%0.1%0.3%0.3%0.3%SupplementControlCholecalciferol0.82% Pb+CholecalciferolControlCholecalciferol0.82% Pb+CholecalciferolSerum 1,25-(OH)2CC<10 pg/mL248 ± 7 pg/mL94 ± 13 pg/mL<10 pg/mL285 ± 44 pg/mL245 ± 46 pg/mLμg/100mL3 ± 19 ± 8352 ± 40<3<3284 ± 36Effect of Pb on serum 1,25-(OH)2CC levels in rats fed low Ca or high Ca dietPb acetate0.82%1 wkIn dietRatDietary Calcium0.02%0.02%0.02%1.2%1.2%1.2%SupplementControlCholecalciferol (50ng/day)0.82% Pb+CholecalciferolControlCholecalciferol (50ng/day)0.82% Pb+CholecalciferolSerum 1,25-(OH)2CC<10 pg/mL754 ± 18 pg/mL443 ± 79 pg/mL<10 pg/mL285 ± 44 pg/mL245 ± 46 pg/mLμg/100mL<3<3284 ± 36Smith et al. (1981)Pb acetate0.15% or 0.45%GD 4 until Day 55In drinking waterRat No effects of Pb on plasma concentrations of vitamin D metabolites, 25-OH D3or 1,25-(OH2)D3, in pubertal male rats exposed to either0.15% or 0.45% Pb acetate in drinkingwater and maintained on an adequate diet.Offspring:0.15% Pb = 67–192 μg/dL; 0.45%Pb = 120–388 μg/dLRonis et al. (2001)

# AX5-127Table AX5-8.2 (cont’d). Regulation of Bone CellFunction in Animals—Systemic Effects of LeadCompoundDose/ConcentrationDuration ExposureRoute Species Effects Blood Level ReferencePbCl20, 0.2, or 0.8%1 or 2 wksIn dietChicks Compared with control animals, Pb exposure significantly increased intestinal calbindinprotein and mRNA levels in addition to plasma 1,25-dihydroxyvitamin D concentration.The effect was present after 1 wk of exposureand continued through the second week. Incalcium-deficient animals increased plasma1,25-dihydroxyvitamin D and calbindin proteinand mRNA were significantly (p < 0.05) inhibited by Pb exposure in a dose dependentfashion over the 2 wk experimental period.None given Fullmer (1995)PbCl20, 0.2, or 0.8%1 or 2 wksIn dietChicks Dose dependent increases in serum 1,25-(OH2)D3levels (and Calbindin-D protein andmRNA) with increasing dietary Pb exposure (0.1% to 0.8%) in experiments performed onLeghorn cockerel chicks fedan adequate calcium diet.None given Fullmer et al.(1996)Short term administration of 1% Pb resulted in significant increases in bone Pb. Totalserum calcium and ionized serum calcium were significantly decreased, as compared tocontrols. Circulating levels of 1,25-(OH2)D3were also decreased, though the rats weremaintained on a normal calcium diet (0.95%).In the long term study, a dose-dependentincrease in parathyroid weight occurred withincreasing exposure to Pb in drinking water.Short term (10 wks) exposureSerum Calcium (mM) Ionized Calcium(mM) 1,25(OH)2D3(pM)Parathyroid Weight (μg/gland)*p < 0.01Controls2.42 ± 0.031.25 ± 0.03232 ± 18.996 ± 34Pb-exposed2.32 ± 0.02*1.15 ± 0.03*177 ± 10.8*178 ± 25*Long term (24 wks) exposurePb in waterNormalized ParathyroidWeight (μg/g body wt)1,25(OH)2D3(pM)Pb acetate1% for 10 wks or0.001–1% for 24 wksIn drinking waterRat0%0.001%0.01%0.1%1.0%p < 0.010.50 ± 0.060.72 ± 0.250.81 ± 0.280.94 ± 0.270.81 ± 0.29*241 ± 32188 ± 27163 ± 17206 ± 24144 ± 33*Short term (10 wk)study:Control:< 0.02 μg/lPb-exposed:> 5μg/lSzabo et al. (1991)

# AX5-128Table AX5-8.2 (cont’d). Regulation of Bone CellFunction in Animals—Systemic Effects of LeadCompoundDose/ConcentrationDuration ExposureRouteSpecies Effects Blood Level ReferencePb nitrate0.02% (125 ppm)GD5 to 1 day beforesacrificeIn drinking waterRat Basal release of growth hormone from control and Pb-exposed pups at age 49 days was notsignificantly different. Growth hormone releasing factor-stimulatedrelease of growthhormone from pituitaries of Pb-exposed pups was smaller thanthe stimulated release ofgrowth hormone from pituitaries of control animals (75% increase over baseline vs. 171%increase, respectively), but the difference did not achieve significance (P = 0.08). Growthhormone content of the pituitary glands was also not influenced by Pb exposure.Rat Pups5 days old: 43.3 ±2.7 μg/dL49 days old: 18.9± 0.7 μg/dL(females: 19.94 ±0.8 μg/dL; males:17.00 ± 1.1 μg/dL)Camoratto et al.(1993)Pb acetate0.05% to 0.45%GD 5 through sacrificeof pups at 21, 35, 55,and 85 daysIn drinking waterRat Pituitary GH content (μg/mg) at postnatal day 55:Control Male Pups = 56.6 ± 8.0; Female Pups = 85.6 ± 9.30.05% Pb Male Pups = 107.2 ± 10.5*; Female Pups = 116.2 ± 9.10.15% Pb Male Pups = 96.8 ± 5.0*; Female Pups = 105.1 ± 7.30.45% Pb Male Pups = 106.0 ± 9.8*; Female Pups = 157.0 ± 9.9**significantly different from control, p < 0.05Offspring:0.05% Pb = 49 ± 6μg/dL; 0.15% Pb =126 ± 16 μg/dL;0.45% Pb = 263 ±28 μg/dLRonis et al.(1998b)Abbreviationsmg—milligramh—hour1,25-(OH)2CC—1,25-dihydroxycholecalcigerolμg—microgram25-OH D3—25-hydroxycholecalciferolPbCl2—lead chloride1,25-(OH)2D3—vitamin D3kg—kilogrammg%—milligram percentpg—picogramGD—gestational daymM—millimolarPb—leadpM—picomolari.v.—intravenous%—percentmL—milliliterdL—decilitermRNA—messenger ribonucleic acidppm—parts per millionGH—growth hormonemin—minute

# AX5-129Table AX5-8.3. Bone Cell Cultures Utilized to Test Effects of LeadCompoundDose/ConcentrationDuration ExposureRoute Species Effects Blood Level ReferenceStable “Pb”5 mg/mL in drinkingwater given duringgestation.On GD 18, 50 μCi210Pb given i.v. topregnant damsRat(fetal boneorgan culture)PTH (3885 IU/mg bone) enhanced cell-mediated release of210Pb from bone. Releaseof210Pb was accompanied by proportional lossof stable Pb and calcium from treatedbones.Time: Release of210Pb (EM/CM ratio)0 min 1.0010 min 0.82 ± 0.052 hr 1.12 ± 0.046 hr 1.59 ± 0.08*24 hr 3.69 ± 0.15*48 hr 3.75 ± 0.09*48 hr 0.78 ± 0.14* (in presence of30 mU/mL salmon calcitonin)*Different from 1.00, p < 0.01.Not given/notapplicableRosen and Wexler(1977)210Pb nitrate6.5 to 65 μM5 min to 2 hIn mediumMice(bone cellisolation fromcalvaria)Uptake of210Pb by OC cells rapid.OC cells have greater avidity for Pb compared to OB cells.OC cell uptake of Pb almost linear vs. little increase in Pb uptake by OB cells withincreasing Pb concentrations in media.15–30% release of210Pb label occurred in OC cells over 2 h time period.Physiological concentrations of PTH resulted in marked increase in210Pb and45Cauptake by OC cells.210Pb uptake linear over PTH concentrations of 50 to 250 ng/mL).Media concentrations of Pb$26 μM enhanced calcium uptake by cells.Not applicable Rosen (1983)210Pb nitrate5 μM20 hoursIn mediumMice(osteoclasticbone cellisolation fromcalvaria)Three readily exchangeable kinetic poolsof intracellular Pb identified, with themajority (~78%) associated with the mitochondrial complex.Not applicable Pounds and Rosen(1986)Pb acetate0 to 50 μM20 hIn mediumMice(osteoclasticbone cellisolation fromcalvaria)Cultures were labeled with45Ca (25 μCi/mL) for 2 or 24 h and kinetic parameterswere examined by analysis of45Ca washout curves.In kinetic analysis using dual-label (1–2 μCi/mL210Pb and 25 μCi/mL45Ca) wash outcurves, the Ca:Pb ratios of the rate constants were ~1:1, suggesting similar cellularmetabolism.Not applicable Rosen and Pounds(1988)

# AX5-130Table AX5-8.3 (cont’d). Bone Cell Cultures Utilized to Test Effects of LeadCompoundDose/ConcentrationDuration ExposureRoute Species Effects Blood Level ReferencePb acetate and210Pblabel0–100 μM20 hrIn mediumMice(osteoclasticbone cellisolation fromcalvaria) andRatOsteosarcomaCells(ROS 17/2.8)Concentrations as high as 100 μM did not causetoxicity in either cell culture. Therewas a slight decrease in growth of ROS cells at 5 μM Pb concentration and a 50%decrease in growth at 25 μM Pb at day 9.210Pb washout experiments with both cell cultures indicated similar steady-state Pbkinetics and intracellular Pb metabolism.Both cell culturesexhibited one large,slowly exchanging pool of Pb, indicative of the mitochondrial pool.Not applicable Long et al. (1990)Pb acetate5 or 25 μMUp to 5 hrIn mediumRatOsteosarcomaCells(ROS 17/2.8)Used19F NMR in combination with 1,2-bis(2-amino-5-fluorophenoxy)ethane-N,N,N’,N’-tetraacetic acid (5F-BAPTA) to distinguishand measure concentrationsof Pb2+and Ca2+in aqueous solution.Basal concentration of [Ca2+]iwas 128 ± 24 nM. Treatment of cells with 5 and 25μM Pb2+produced sustained 50% and 120% increases in [Ca2+]i, respectively, over a5 hour exposure period.At a medium concentration of 25 μM Pb2+a measurable entry of Pb2+into the cells([Pb2+]iof 29 ± 8 pM) was noted.Not applicable Schanne et al.(1989)Pb nitrate5 μM20 minIn mediumRat(osteoblasticbone cellisolation fromcalvaria)Pb (5 μM) linearly raised the emission ratio of FURA-2 loaded cells 2-fold within 20min of application, most likely due to increase in [Pb2+]irather than increase in[Ca2+]i.Intracellular calcium increased even in the absence of extracellular calcium.Not applicable Schirrmacher et al.(1998)Pb2+5 or 12.5 μMUp to 100 minIn mediumRat(osteoblasticbone cellisolation fromcalvaria)5 or 12.5 μM Pb2+applied simultaneously with re-added calcium reduced immediateCRAC to 70% or 37% of control value, respectively.During CRAC a large influx of Pb2+occurred, leading to a 2.7-fold faster increase inthe FURA-2 excitation ratio. These effects were exclusive of any inhibitory actionof Pb2+on calcium ATPase activity.Not applicable Wiemann et al.(1999)

# AX5-131Table AX5-8.3 (cont’d). Bone Cell Cultures Utilized to Test Effects of LeadCompoundDose/ConcentrationDuration ExposureRouteSpecies Effects Blood Level ReferencePb nitrate0–150 μMUp to 72 hrIn mediumMice (bonecell isolationfrom parietalbones)Pb2+concentrations of 50 μM and above stimulated release of hydroxyproline andpreviously incorporated45Ca from organ culture. This did not occur in boneinactivated by freezing and thawing. Eel calcitonin, bafilomycin A1, and scopadulcicacid B significantly inhibited Pb mediated45Ca release. There was a high correlationbetween45Ca and PGE2release (p < 0.001), inferring Pb-induced bone resorptionmediated by PGE2. This was further supported by the significant depression of Pb-stimulated45Ca release that occurred with concurrent exposure to 10 μM of eitherindomethacin or flurbiprofen, both inhibitors of cyclooxygenase.Not applicable Miyahara et al.(1995)Pb acetate0–25 μM48 hrIn mediumRatOsteosarcomaCells(ROS 17/2.8)Osteocalcin production incells treated with 100 pg1,25-dihydroxyvitamin D3/mL ofmedium and 0 μM Pb2+for 16, 24, or 36 h was 20.1 ± 2.1, 23.5 ± 3.4, 26.1 ± 2.5 in celldigests, and 87.2 ± 3.3, 91.6 ± 6.7, 95.1 ± 5.2 in the medium, respectively. Thepresence of 25 μM Pb2+in the medium, reduced osteocalcin levels to as low as 30% ofcontrol levels.Cells treated with 0, 5, 10, or 25 μM Pb acetate for 24 h, followed by an additional24 h exposure to 0 or 100 pg of 1,25-dihydroxyvitamin D3and continued Pb2+exposure, resulted in a concentration-dependent reduction of 1,25-dihydroxyvitaminD3-stimulated osteocalcin secretion. 10 μM Pb resulted inmedium osteocalcin levelssimilar to control levels, however, 25 μM Pb resulted in about a 30% decrease.Cellular osteocalcin levels were unaffected.Not applicable Long et al. (1990)Pb glutamate4.5H10−5to4.5H10−7M2, 4, or 6 daysIn mediumRatOsteosarcomaCells(ROS 17/2.8)In the presence of serum in the cultures, concentrations of Pb2+less than 4.5H10−5Mhad no effect on cell proliferation. In the absence of serum, 4.5H10−7M Pb2+increased proliferation at Day 4 and 4.5H10−6M Pb2+inhibited proliferation at Day 6.Pb exposure for 48 h (4.5H10−6M) significantly (p < 0.01) increased total proteinproduction in cells and media of cultures labeled with [3H] proline, but did notincrease collagen production. Protein synthesis and osteonectin were enhanced incells following Pb2+exposure.Not applicable Sauk et al. (1992)Pb glutamate4.5H10−5M–10−7M1,3, or 5 daysincubationIn mediumHumanDental PulpCellsAll concentrations significantly increasedcell proliferation on Day 1, 3, and 5 ofexposure in serum free conditions. Pb exposure resulted in dose-dependent decreasein intracellular protein and procollagen Iproduction over 5 days. In presence of serumonly, 4.5H10−5M Pb2+significantly increased protein production, however, at thatsame concentration Pb significantly decreased osteocalcinproduction (i.e., reduced thelevel of osteocalcinby 55% at 12 hr).Not applicableThaweboon et al.(2002)

# AX5-132Table AX5-8.3 (cont’d). Bone Cell Cultures Utilized to Test Effects of LeadCompoundDose/ConcentrationDuration ExposureRouteSpecies Effects Blood Level ReferencePb glutamate5–20 μM48 hrIn mediumRatOsteosarcomaCells(ROS 17/2.8)Cells treated with 0, 5, 10, or 20 μM Pb acetate for 24 h, followed by an additional24 h exposure to 0 or 100 pg of 1,25-dihydroxyvitamin D3and continued Pb2+exposure, resulted in a significant (p < 0.05or less) reduction of osteocalcin secretion,both in the presence and absence of 1,25-dihydroxyvitamin D3at all Pb2+concentrations. This effect is not mediated by PKC.Not applicable Guity et al. (2002)Pb0.5 to 5 μM40 minIn mediumRatOsteosarcomaCells(ROS 17/2.8)1 and 5 μM Pb2+significantly increased [Ca2+]iin the absence of 1,25-dihydroxyvitamin D3and significantly reduced the peak elevation in [Ca2+]iinducedby 1,25-dihydroxyvitamin D3.Simultaneous treatment of previously unexposed cells to Pb2+and 1,25-dihydroxyvitamin D3produced little reduction in the 1,25-dihydroxyvitamin D3-induced45Ca uptake, while 40 min of treatment with Pb2+before addition of 1,25-dihydroxyvitamin D3significantly reduced the1,25-dihydroxyvitamin D3-inducedincrease in45Ca influx.Not applicable Schanne et al.(1992)Pb nitrate5H10−4to 5H10−15M24 hIn mediumRatOsteosarcomaCells(ROS 17/2.8)Osteocalcin secretion significantly reduced below control values by culture with 1 μMPb2+in the presence or absence of added 1,25-dihydroxyvitamin D3or 1,25-dihydroxyvitamin D3and IGF-I. Inhibition of osteocalcin secretion was almostcomplete in either hormone-stimulated or basal cultures with the addition of 100 μMPb2+. Cellular alkaline phosphatase activityparalleled those ofosteocalcin, thoughthere was no response to IGF-I alone or in combination with 1,25-dihydroxyvitaminD3. Pb2+at 10−15, 10−12, and 10−9to 10−7M did not influence DNAcontents of cellcultures, but 1 μM significantly (p < 0.05)inhibited basal cultures and those with IGFI + D3. Cell cultures exposed to 1,25-dihydroxyvitamin D3and Pb2+were inhibited at10 μM Pb2+.Not applicable Angle et al. (1990)Pb acetate2 to 200 μM72 hIn mediumRatOsteosarcomaCells(ROS 17/2.8)Pb (2 to 200 μM) had no effect on cell number or DNA and protein synthesis.Alkaline phosphatase activity was significantly reduced (p < 0.001) by Pb in a doseand time-dependent manner.Pb Concentration. Alkaline Phosphatase Inhibition2 μM. 10.0 ± 1.1%20 μM. 22.0 ± 6.4%200 μM. 57.8 ± 8.8%Reductions in alkaline phosphatase mRNA levels mirrored Pb2+-induced inhibition ofenzyme activity.Not applicable Klein and Wiren(1993)

# AX5-133Table AX5-8.3 (cont’d). Bone Cell Cultures Utilized to Test Effects of LeadCompoundDose/ConcentrationDuration ExposureRouteSpecies Effects Blood Level ReferenceUnidentified Pb2+Various incubationtimesNot applicableBovine(Bovine-derivedosteocalcin)Binding studies of Ca2+to osteocalcin suggested asingle binding site with adissociation constant (Kd) of 7 ± 2 μM for Ca-osteocalcin. Competitive displacementexperiments by addition of Pb2+indicated the Kd for Pb-osteocalcin is 1.6 ± 0.42 nM,~3 orders of magnitude higher.Not applicable Dowd et al. (1994)Unidentified Pb2+Various incubationtimesNot applicableBovine(Bovine-derivedosteocalcin)Circular dichroism indicated Pb2+binding induced a structural change in osteocalcinsimilar to that found in Ca2+binding, but at 2 orders of magnitude lower concentration.Pb2+has 4 orders of magnitude tighter binding to osteocalcin (Kd = 0.085 μM) thanCa2+(Kd = 1.25 mM). Hydroxyapatite binding assays showed similar increasedadsorption of Pb2+and Ca2+to hydroxyapatite, but Pb2+adsorption occurred at aconcentration 2–3 orders lower than Ca2+.Not applicable Dowd et al. (2001)Pb acetate10 μM2 hIn mediumRatOsteosarcomaCells(ROS 17/2.8)Pb2+treatment reduced the unidirectional rate of ATP synthesis (Pito ATP) by a factorof 6 or more (∆M/Mo: Control = 0.18 ± 0.04, Pb2+< 0.03). Intracellular free Mg2+concentration decreased 21% after 2 h of 10 μM Pb2+treatment (0.29 ± 0.02 mM priorto Pb2+treatment and 0.23 ± 0.02 mM after 2 h of Pb2+treatment, p < 0.05).Not applicable Dowd et al. (1990)Pb acetate5 or 25 μMUp to 24 hIn mediumRatOsteosarcomaCells(ROS 17/2.8)5 μM Pb2+significantly altered effect of EGF on intracellular calcium metabolism.In cells treated with 5 μM Pb2+and 50 ng/mL EGF, there was a 50% increase in totalcell calcium over cells treated with 50 ng/mL EGF alone.Not applicable Long and Rosen(1992)Pb acetate5 or 25 μM20 hIn mediumRatOsteosarcomaCells(ROS 17/2.8)Treatment with 400 ng/mL culture medium for 1 h or with 25 μM Pb2+for 20 hincreased total cell calcium:TreatmentCell CalciumControl7.56 ± 1.05 nmol/mg proteinPTH (400 ng/mL) 23.28 ± 1.40* nmol/mg proteinPb (25 μM) 11.37 ± 0.57* nmol/mg proteinPTH + Pb 37.88 ± 4.21* nmol/mg protein* p#0.05 from controlNot applicable Long et al. (1992)

# AX5-134Table AX5-8.3 (cont’d). Bone Cell Cultures Utilized to Test Effects of LeadCompoundDose/ConcentrationDuration ExposureRouteSpecies Effects Blood Level ReferencePb acetate10−11to 10−7M3 minIn mediumRatOsteosarcomaCells(ROS 17/2.8)Treatment of ROS cells with Pb at 1 or 5 μM concentrations produced a rise in [Ca2+]ito 170 nM and 230 nM, respectively, over thebasal level of 125 nM. An elevation in[Ca2+]ito 210 nM occurred during treatment with an activator of PKC, phorbol 12-myristate 13-acetate (10 μM). Pretreatment with a selective inhibitor of PKC,calphostin C, did not change basal [Ca2+]i, but prevented the Pb-induced rise in [Ca2+]i.Free Pb2+activated PKC in a range from 10−11to 10−7M, with a Kcat (activationconstant) of 1.1H10−10M and a maximum velocity (Vmax) of 1.08 nmol/mg/mincompared with Ca activation of PKC over a range of 10−8to 10−3M, with a Kcat of3.6H10−7M, and a Vmax of1.12 nmol/mg/min.Not applicable Schanne et al.(1997)Pb acetate0.5 to 60 μM24 to 48 hIn mediumHumanOsteosarcomaCells (HOSTE 85)andRatOsteosarcomaCells(ROS 17/2.8)HOS TE 85 CellsInhibition of proliferation (IC50) = 4 μM PbCytotoxicity = 20 μM PbROS 17/2.8 CellsInhibition of proliferation (IC50) = 6 μM PbCytotoxicity = 20 μM PbHighest Pb concentration in both celltypes found in mitochondrial fraction.Not applicable Angle et al. (1993)Pb acetate or Pbchloride0.1 to 200 μM24 h to 6 daysIn mediumChick growthplatechondrocytesGrowth plate chondrocytes were exposed to 3 or 30 μM for up to 6 days. Maximalinhibition of cell proliferation as measured by thymidine incorporation occurred after a3-day exposure to Pb. A similar 40% inhibition was found at both concentrations.Higher concentrations (up to 100 μM)did not produce further inhibition.In cultures treated for 24 h, Pb produced a dose-dependent inhibition of alkalinephosphatase, with 10 μM producing maximal inhibition (40–50% inhibition). Effectsof Pb on proteoglycan synthesis were not found until after 48 h of exposure, withmaximal effect after 72 h of exposure (twofold, 30 μM). Pb exposure (10 to 200 μM)for 24 h produced a dose-dependent inhibition of both type II and type X collagensynthesis.Not applicable Hicks et al. (1996)

# AX5-135Table AX5-8.3 (cont’d). Bone Cell Cultures Utilized to Test Effects of LeadCompoundDose/ConcentrationDuration ExposureRouteSpecies Effects Blood Level ReferencePb acetate0.1 to 30 μM24 hIn mediumChickengrowth plateand sternalchondrocytesA dose-dependent inhibition of thymidine incorporation into growth platechondrocytes was found with exposure to 1–30 μM Pb for 24 h. A maximal 60%reduction occurred at 30 μM. Pb bluntedthe stimulatory effects on thymidineincorporation produced by TGF-β1 (24% reduction) and PTHrP (19% reduction),however, this effect was less than with Pb alone. Pb (1 and 10 μM) increased type Xcollagen in growth plate chondrocytes ~5.0-fold and 6.0-fold in TGF-β1 treatedcultures and 4.2-fold and 5.1-fold in PTHrP treated cultures when compared withcontrols, respectively. Pb exposure alone reduced type X collagen expression by70–80%.Not applicable Zuscik et al.(2002)AbbreviationsPb—leadμCi—microCurieIU—international unitshr—hourOB—osteoblast5F-BAPTA—1,2-bis(2-amino-5-fluorophenoxy)ethane-N,N,N’,N’-tetraacetic acid[Pb2+]i—free intracellular leadFURA-2—1-[6-Amino-2-(5-carboxy-2-oxazolyl)-5-benzofuranyloxy]-2-(2-amino-5-methylphenoxy) ethane-N,N,N',N'-tetraacetic acidM—molarDNA—deoxyribonucleic acid∆M—decrease in magnetization of intracellular Piupon prolonged saturation of gammaphosphate of ATPmM—millimolarKcat—activation constantIC50—inhibitory concentration 50%mg—milligram210Pb—lead-210 radionuclideEM—experimental mediummU—milliunits45Ca—calcium-45 radionuclideCRAC—calcium release activated calcium refluxpg—picogrammRNA—messenger ribonucleic acidng—nanogramVmax—maximum velocityTGF-β1—transforming growth factor-beta 1mL—milliliteri.v.—intravenousCM—control mediumμM—micromolarng—nanogram[Ca2+]i—free intracellular calciumPGE2—prostaglandin E2PKC—protein kinase CKd—dissociation constantnmol—nanomoleHOS TE 85 cells—human osteosarcoma cellsPTHrP—parathyroid hormone-related proteinGD—gestational dayPTH—parathyroid hormonemin—minuteOC—osteoclastROS 17/2.8—rat osteosarcoma cellsnM—nanomolarh—hourIGF-I—insulin growth factor IATP—adenosine triphosphateEGF—epidermal growth factor

# AX5-136Table AX5-8.4. Bone Lead as a Potential Sourceof Toxicity in Altered Metabolic ConditionsCompoundDose/ConcentrationDuration ExposureRouteSpecies Effects Blood Level ReferencePb acetate200 μg/mL105 days prior to matingor 105 days prior tomating and duringgestation and lactation(160 days)In drinking waterMice Results suggested very little Pb wastransferred from mother to fetus duringgestation, however, Pb transferred in milk and retained by the pups accountedfor 3% of the maternal body burden of those mice exposed to Pb prior tomating only. The amount of Pb retainedin these pups exceeded that retainedin the mothers, suggesting lactationeffectively transfers Pb burden frommother to suckling offspring. Transfer of Pb from mothers was significantlyhigher when Pb was supplied continuouslyin drinking water, rather thanterminated prior to mating.Not given Keller and Doherty(1980)Pb acetate12 mM8 wks prior to matingand during gestationIn drinking waterRat Considerably higher lactational transfer of Pb from rat dams compared toplacental transfer was reported. Continuous exposure of rat dams to Pb untilday 15 of lactation resulted in milk Pb levels 2.5 times higher than in wholeblood, while termination of maternalPb exposure at parturition yieldedequivalent blood and milk levels ofPb, principally from Pb mobilized frommaternal bone.Concentration (μg/l) inwhole blood at day 15 oflactation:Controls = 14 ± 4; Pb-exposed until parturition =320 ± 55; Pb-exposeduntil day 15 of lactation =1260 ± 171**p < 0.001 compared withdams at parturition.Palminger Hallénet al. (1996)Pb acetate100 ppm(A) Exposure for 158 ±2 days from 21 days ofage to midlactation; (B)Exposure 144 ± 2 daysfrom day 21 up todelivery; (C) Exposureonly during lactation;(D, E, and F) groups ofnonpregnant ratsexposed for periodsequivalent to groups A,B and C, respectively.In drinking waterRat In rats exposed to Pb 144 days prior tolactation (B), theprocess of lactationitself elevated blood Pb and decreasedbone Pb, indicating mobilization of Pbfrom bone as there was no external sourceof Pb during the lactation process.Rats exposed to Pb for 158 days (A)(144days prior to lactation and 14 daysduring lactation) also experienced elevated blood Pb levels and loss of Pb frombone. Pb exposure only during the 14 days of lactation was found tosignificantly increase intestinal absorption and deposition (17 fold increase) ofPb into bone compared to nonpregnant rats, suggesting enhanced absorption ofPb takes place during lactation. The highest concentration of Pb in bone wasfound in nonpregnant, nonlactating control animals, with significantlydecreased bone Pb in lactating rats secondary to bonemobilization and transfervia milk to suckling offspring.Concentration (μg/dL) inwhole blood at day 14 oflactation or equivalent:Group A = 31.2 ± 1.1;Group B = 28.0 ± 1.7;Group D = 27.3 ± 2.2;Group E = 24.7 ± 1.2Maldonado-Vegaet al. (1996)

# AX5-137Table AX5-8.4 (cont’d). Bone Lead as a Potential Source of Toxicity in Altered Metabolic ConditionsCompoundDose/ConcentrationDuration ExposureRouteSpecies Effects Blood Level ReferencePb acetate100 ppm(A) Exposure for 158 ±2 days from 21 daysthrough 14 days oflactation; (B)Nonpregnant controlGroup A; (C) Exposure144 ± 2 days from day21 up to delivery; (D)Nonpregnant controlGroup C; (E) Lactatingrats not exposed to Pb;(F) Nonpregnant ratsnot exposed to Pb.In drinking waterRat When dietary calcium was reducedfrom the normal 1 to 0.05%, bone calciumconcentration decreased by 15% and bone Pb concentration decreased by 30%during the first 14 days oflactation. In nonlactating rats on the 0.05% calciumdiet, there were also decreases inbone calcium, but no incremental boneresorption nor Pb efflux from bone, suggesting the efflux from bone duringlactation was related to bone resorption.Enhancement of calcium (2.5%) inthe diet of lactating rats increased calcium concentration in bone by 21%, butdid not decrease bone resorption, resulting in a 28% decrease in bone Pbconcentration and concomitant rise in systemic toxicity.Concentration (μg/dL) inwhole blood at day 14 oflactation or equivalent:Group B = 26.1 ± 2.1,Group A = 32.2 ± 2.7*;Group D = 23.8 ± 2.1,Group C = 28.2 ± 2.2*;Groups E and F = 5.1 ±0.4.* p < 0.01, compared toappropriate controlMaldonado-Vegaet al. (2002)Pb acetate250 mg/mLBeginning at 5 wks ofage, rats exposed to Pbfor 5 wks, followed byno additional exposure.In drinking waterRat Demonstrated adverse effects in ratoffspring born to females whose exposureto Pb ended well before pregnancy. Five wk-old-female rats given Pb acetatein drinking water (250 mg/mL) for fivewks, followed by a one mo periodwithout Pb exposure before mating. Totest the influence of dietary calciumon Pb absorption and accumulation, some pregnant rats were fed dietsdeficient in calcium (0.1%) while others were maintained on a normal calcium(0.5%) diet. All Pb-exposed dams and pups had elevated blood Pb levels;however, pups born to dams fed the dietdeficient in calcium during pregnancyhad higher blood and organ Pb concentrations compared to pups from damsfed the normal diet. Pups born to Pb-exposed dams had lower mean birthweights and birth lengths than pups born to non-Pb-exposed control dams(p < 0.0001), even after confounders such as litter size,pup sex, and damweight gain were taken into account.Blood Pb concentration ofpups (μM): Lowcalcium/no Pb = 0.137 ±0.030C; Low calcium/Pb =1.160 ± 0.053A; Normalcalcium/No Pb = 0.032 ±0.003C; Normalcalcium/Pb = 0.771 ±0.056B.Values that are notmarked by the same letterare significantly different(p < 0.05).Han et al. (2000)

# AX5-138Table AX5-8.4 (cont’d). Bone Lead as a Potential Source of Toxicity in Altered Metabolic ConditionsCompoundDose/ConcentrationDuration ExposureRouteSpecies Effects Blood Level ReferencePb acetate1500 μg/CommonPb/kg/d~10 yrs, replaced by a204Pb-enriched dose(50 days), then206Pb-enriched dose(50 days), and finally a207Pb-enriched dose(50 days, with reducedconcentration)Orally, in gelatincapsuleNonhumanPrimateSequential doses of Pb mixes enriched in stable isotopes (204Pb,206Pb,and207Pb) were administered toa female cynomolgus monkey (Macacafascicularis) that had been chronically administered a common Pb isotope mix.The stable isotope mixes served as a marker of recent, exogenous Pb exposure,while the chronically administered common Pb served as a marker ofendogenous (principally bone) Pb. Fromthermal ionization mass spectrometryanalysis of the Pb isotopic ratios ofblood and bone biopsies collected at eachisotope change, and using end-memberunmixing equations, it was determinedthat administration of the first isotope label allowed measurement of thecontribution of historic bone storesto blood Pb. Exposure to subsequentisotopic labels allowed measurementsof the contribution from historic bonePb stores and the recently administered enriched isotopes that incorporatedinto bone. In general the contribution from the historic bone Pb (common Pb)to blood Pb level was constant (~20%), accentuated with spikes in total bloodPb due to the current administration ofthe stable isotopes. After cessation ofeach sequential administration, the concentration of the signature dose rapidlydecreased.Total blood Pb range:31.2 to 62.3 μg/100g.Inskip et al. (1996)Pb acetate1300 to1500 μg/CommonPb/kg/d~10 yrs, replaced by a204Pb-enriched dose(47 or 281 days), then206Pb-enriched dose(50 or 105 days), andfinally a207Pb-enricheddose (50 days, with650 μg concentration inonly one primate)Orally, in gelatincapsuleNonhumanPrimateInitial attempts to apply a single bone physiologically based model of Pbkinetics were unsuccessfuluntil adequate explanation of these rapid drops instable isotopes in the blood were incorporated. Revisions were added toaccount for rapid turnover of the trabecular bone compartment and slowerturnover rates of cortical bone compartment, an acceptable model evolved.From this model it was reported that historic bone Pb from 11 yrs ofcontinuous exposure contributes ~17% ofthe blood Pb concentration at Pbconcentration over 50 μg/dL, reinforcing the concept that the length of Pbexposure and the rates of past and current Pb exposures help determine thefractional contribution of bone Pb to total blood Pb levels. The turnover ratefor cortical (~88% of total bone byvolume) bone in the adult cynomolgusmonkey was estimated by the model tobe ~4.5% per yr, while the turnoverrate for trabecular bone was estimated to be 33% per yr.Various O’Flaherty et al.(1998)

# AX5-139Table AX5-8.4 (cont’d). Bone Lead as a Potential Source of Toxicity in Altered Metabolic ConditionsCompoundDose/ConcentrationDuration ExposureRouteSpecies Effects Blood Level ReferencePb acetate1100 to1300 μg/CommonPb/kg/d~14 yrs, replaced by a204Pb-enriched dose,206Pb-enriched dose,and/or finally a207Pb-enriched dose ofvaried durations andconcentrations.Orally, in gelatincapsuleNonhumanprimateUsing the method of sequential stableisotope administration examined flux ofPb from maternal bone during pregnancy of 5 female cynomolgus monkeys.Blood Pb levels in maternal blood attributable to Pb from mobilized bone werereported to drop 29 to 56% below prepregnancy baseline levels during the firsttrimester of pregnancy. This was ascribed to the known increase in maternalfluid volume, specific organ enlargement (e.g., mammary glands, uterus,placenta), and increased metabolic activity that occurs during pregnancy.During the second and third trimesters, when there is a rapid growth in thefetal skeleton and compensatory demand for calcium from the maternal blood,the Pb levels increased up to 44% over pre-pregnancy levels. With theexception of one monkey, blood Pb concentrations in the fetus corresponded tothose found in the mothers, both in total Pb concentration and proportion of Pbattributable to each isotopic signature dose (common = 22.1% vs. 23.7%,204Pb = 6.9% vs. 7.4%, and206Pb = 71.0% vs. 68.9%, respectively). Between7 and 25% of Pb found in fetal bone originated from maternal bone, with thebalance derived from oral dosing of the mothers with isotope duringpregnancy.In offspring from a low Pb exposure control monkey (blood Pb <5 μg/100 g)~39% of Pb found in fetal bone was of maternal origin, suggesting enhancedtransfer and retention of Pb under low Pb conditionsVarious, with total bloodPb as high as ~65 μg/100 gFranklin et al.(1997)Pb acetate250 mg/LExposure began eitherat 5, 10, or 15 wks ofage and continued for atotal of 5 wks.Drinking waterRat Exposed rats for 5 wks to 250 mg/l Pbas acetate in drinking water beginningat 5 wks of age (young child), 10 wks of age (mid-adolescence), or 15 wks ofage (young adult), followed by a 4 wk period of without Pb exposure.An additional group of rats were exposed to Pb beginning at 5 wks, butexamined following an 8 or 20 wk period after cessation of Pb. Significantlylower blood and bone Pb concentrationswere associated with greater age atthe start of Pb exposure and increased interval since the end of exposure.Young rats beginning exposure to Pb at5 wks and examined 20 wks aftercessation of exposure still, however, had bone Pb concentrations higher thanthose found in older rats only 4 wks after cessation of exposure.Pb concentration (μM)4 wks after cessation of Pbexposure:Exposure started at 5 wksof age = 1.39 ± 0.09;Exposure started at 10 wksof age = 1.18 ± 0.12;Exposure started at 15 wksof age = 0.82 ± 0.05.Han et al. (1997)

# AX5-140Table AX5-8.4 (cont’d). Bone Lead as a Potential Source of Toxicity in Altered Metabolic ConditionsCompoundDose/ConcentrationDuration ExposureRouteSpecies Effects Blood Level ReferencePb acetate50 ppm11 moDrinking waterRat Studied differences in tissue distribution of Pb in adult and old rats. Adult(8 mo old) and old (16 mo old) rats were exposed to 50 ppm Pb acetate indrinking water for 11 mo at which time the experiment was completed. Bone(femur) Pb levels in older rats were found to be less than those in younger rats,however, blood Pb levels were higher in the older rats. Brain Pb concentrationin the older rats exposed to Pb weresignificantly higher, and brain weightsignificantly less than the brain Pb concentration and weights of unexposedolder control rats or adult ratsexposed to Pb, suggesting a potentialdetrimental effect. Authors suggested that a possibility for the observeddifferences in tissue concentrations of Pb was due to changes in the capacity ofbone to store Pb with advanced age.Approximate medianvalues after 6 mo ofexposure:Adult rats : 23 μg/dLOld rats: 31 μg/dLAfter 11 mo of exposure:Adult rats: 16 μg/dLOld rats: 31 μg/dLCory-Slechta et al.(1989)Pb acetate0, 2, or 10 mg/kg/d9.5 moDrinking waterRat Examined kinetic and biochemical responses of young (21 days old), adult(8 mo old), and old (16 mo old) rats exposed to Pb at 0, 2, or 10 mg Pbacetate/kg/d over a 9.5 mo experimental period. Results suggested older ratsmay have increased vulnerability to Pbdue to increased exposure of tissues toPb and greater sensitivity of the tissues to the effects of Pb.Various from ~1 μg/dLup to 45 μg/dLCory-Slechta(1990b)Pb acetate7 yrs totalDrinking waterNonhumanprimateIn studies of bone Pb metabolism ina geriatric, femalenonhuman primatesexposed to Pb ~10 yrs previously, there were no significant changes in bonePb level over a 10 mo observation period as measured by109CD K X-rayfluorescence. The mean half-life of Pbin bone of these animals was found tobe 3.0 ± 1.0 yrs, consistent with data found in humans, while the endogenousexposure level due to mobilized Pb was0.09 ± 0.02 μg/dL blood.Historic concentrationsduring exposure: 44 to89 μg/100 mL.McNeill et al.(1997)Pb (type unidentified)occurring naturally indiet (0.258 ng/mg drywt) and water(5.45 ppb).Exposure from age1 mo up to 958 days.Drinking water and dietMice The Pb content of femurs increased by 83% (values ranged from 0.192 to 1.78ng Pb/mg dry wt), no significant relationship was found between Pb and bonedensity, bone collagen, or loss of calcium from bone. The results suggestagainstlow levels of bone Pb contributing to the osteopenia observed normallyin C57BL/6J mice.None given Massie and Aiello(1992)

# AX5-141Table AX5-8.4. (cont’d). Bone Lead as a PotentialSource of Toxicity in Altered Metabolic ConditionsCompoundDose/ConcentrationDuration ExposureRouteSpecies Effects Blood Level ReferencePb acetate250 mg/lExposure for 5 wksDrinking waterRat Rats were exposed to Pb for 5 wks, followed by a 4 wk washout periodwithout Pb to allow primarily accumulation in the skeleton. Rats were thenrandomly assigned to a weight maintenance group (WM), amoderate weightloss (MWL) group (70% of maintenance diet), or a substantial weight loss(SWL) group (40% of maintenance diet) for a 4 wk period. At the end of thisexperimental period the blood and bone levels of Pb did not differ betweengroups, however, the amount and concentration of Pb in the liver increasedsignificantly.Treatment Group Pb (nmol/g)Femur WM 826 ± 70MWL 735 ± 53SWL 935 ± 84Spinal Column Bone WM 702 ± 67MWL 643 ± 59SWL 796 ± 59WM = 1.25 ± 0.10 μM;MWL = 1.16 ± 0.10 μM;WM = 1.32 ± 0.10 μM;Han et al. (1996)Pb acetate250 μg/l14 daysDrinking waterRat Study was undertaken to determine theeffect of weight loss and exercise onthe distribution of Pb. Weight loss secondary to dietary restriction was acritical factor elevating organ Pb levels and, contrary to prior study (Han et al.(1996)), elevated blood levels of Pb.No significant difference in organ orblood Pb concentrations were reportedbetween the exercise vs. no exercisegroups.Graphs indicateconcentrations rangingfrom 0.20 to 2.00 μM.Han et al. (1999)Abbreviationsμg—microgrammL—milliliter%—percentmM—millimolarl—literppm—parts per milliondL—decilitermg—milligramμM—micromolarPb—leadkg—kilogramg—gram204Pb,206Pb,207Pb—Stable isotopes of lead204, 206, 207, respectivelywt—weightppb—parts per billion

# AX5-142Table AX5-8.5. Uptake of Lead by TeethCompoundDose/ConcentrationDuration ExposureRoute Species Effects Blood Level ReferencePb acetate1 μg/kg body weightSingle IP injectionRat Uptake of Pb label into incisors of suckling rats:0.7% of injected dose in 4 incisors of suckling rat after 24 h,1.43% after 192 h. 0.6% of injected dose in 4 incisors of adult after 24 h,0.88% after 192 h.Mean percent of dose aftertime:Suckling:3.04% after 24 h1.71% after 72 h1.52% after 144 h1.18% after 192 hAdult:6.40% after 24 h3.41% after 24 h1.92% after 24 h1.04% after 72 h0.72% after 144 h0.48% after 192 hMomčilovićandKostial (1974)Pb aerosol77, 249, or 1546 μg/m3for 50 to 70 daysInhalationRat 11 micrograms Pb/g incisor taken up in animals exposed to 77 μg/m3for70 days vs. 0.8 μg Pb/g in control animals13.8 μg Pb/g incisor in rats exposed to 249 μg/m3for 50 days153 μg Pb/g incisor in rats exposed to 1546 μg/m3for 50 daysControl: 2.6 μg/dL77 μg/m3: 11.5 μg/dL249 μg/m3: 24.1 μg/dL1546 μg/m3: 61.2 μg/dLGrobler et al. (1991)Pb acetate0, 3, or10 ppmDuring pregnancy and21 days of lactationDrinking waterRat Pb concentration in teeth of offspring:0 ppm group–Incisors (1.3 ppm), 1st molars (0.3 ppm)3 ppm group–Incisors (1.4 ppm), 1st molars (2.7 ppm)10 ppm group–Incisors (13.3 ppm), 1st molars (11.4 ppm)Not givenGrobler et al. (1985)Abbreviationsμg—microgramkg—kilogramIP—intraperitoneal%—percenth—hourm3—cubic meterPb—leadg—gramppm—parts per million

# AX5-143Table AX5-8.6. Effects of Lead onEnamel and Dentin FormationCompoundDose/ConcentrationDuration ExposureRouteSpecies Effects BloodLevelReferencePb “salt”0.075 mM/100 g ,0.15 mM/100 g or1.5 mM/100 gSingle, SC injectionRat 0.075 mM dose, no disruption of dentin and enamel.0.15 mM dose, mild mineralizationdisruption of dentin and enamel.1.5 mM dose, mild tomoderate disruption ofdentin and enamel.Not givenEisenmann and Yaeger(1969)Pb acetate30 mg/kgSingle, i.v. injectionRat Rapid rise in serum calciumand phosphorus after injection.Formation of a “Pb line” in growing dentin within 6 hr after injection.Not givenAppleton (1991)Pb acetate3 mg/kgSingle, i.v. injectionRat Production of a hypomineralized band in dentin.Not givenAppleton (1992)Pb acetate0 mg/l, 34 mg/l, or170 mg/l70 daysDrinking waterRat Increased in relative amountof protein in enamel matrix.Significant (p < 0.05) decrease in microhardness values of groups exposedto Pb in regions of maturation enamel, but not fully mature enamel.Delay in enamel mineralization in animals exposed to Pb.0 mg/l group: 0 ppm34 mg/l group:18.1 ppm170 mg/l group:113.3 ppmGerlach et al. (2002)Pb acetate40 mg/kgSingle, IP injectionRat Significantly (p < 0.05) reduced eruption rates at various time points(days 8, 14, 16, 22, 24, 28) under hypofunctional conditions.Days after injection0 days: 48 μg/dL10 days: 37 μg/dL20 days: 28 μg/dL30 days: 16 μg/dL(Values estimated fromgraph)Gerlach et al. (2000b)AbbreviationsPb—leadmM—millimolarg—gramSC—subcutaneousmg—milligramkg—kilogrami.v.—intravenousl—literppm—parts per millionIP—intraperitonealμg—microgramdL—deciliter

# AX5-144Table AX5-8.7. Effects of Lead on Dental Pulp CellsCompoundDose/ConcentrationDuration ExposureRoute Species Effects Blood Level ReferencePb glutamate4.5H10−5M–10−7M1,3, or 5 daysincubationHumanDentalPulp CellsAll concentrations significantly increased cell proliferation on Day 1, 3 and5 of exposure in serum free conditions. Pb exposure resulted in dose-dependent decrease in intracellularprotein and procollagen I productionover 5 days. In presence of serum only 4.5H10−5M significantly increasedprotein production. Pb significantlydecreased osteocalcin production.Not applicable Thaweboon et al. (2002)AbbreviationsPb—leadM—molar

# AX5-145Table AX5-8.8. Effects of Leadon Teeth—Dental CariesCompoundDose/ConcentrationDuration ExposureRoute Species Effects Blood Level ReferencePb acetate0.5 mEq84 days males98 days femalesDrinking waterHamster Significant increase in dental caries in male hamsters only(85 mean molar caries score control vs. 118 for Pb exposed).No significant difference in dental caries in female hamsters(68 mean molar caries score control vs. 85 for Pb exposed).Not givenWisotzky and Hein (1958)Pb acetate34 ppmPre- and perinatalDrinking waterRat Pb exposure resulted in an almost 40% increase in theprevalence of caries and nearly 30% decrease in stimulatedparotid salivary gland function.Control: <5 μg/dL34 ppm Pb: 48 ±13 μg/dLWatson et al. (1997)Pb acetate10 or 25 ppm Pb3 wksDrinking waterRat When 15 ppm fluoride was concurrently given in diet, Pb didnot increase prevalence of caries.Not givenTabchoury et al. (1999)AbbreviationsmEq—milliequivalentsd—daysppm—parts per million%—percentμg—microgramdL—deciliter

# AX5-146 

# ANNEX TABLES AX5-9

# AX5-147Table AX5-9.1. Studies on Lead Exposure and Immune Effects in HumansNature ofExposureDose or Blood Lead Levels(BLLs)Sample PopulationReported EffectsReferenceEnvironmental10.1–48.2 μg/L (BLL)2nd grade children living nearindustrial waste incinerator or otherindustries causing pollutionIncreased blood Pb concentration associated w/ increased IgE, especially above28 μg/dL.Also decreased T-cells, cytotoxic T-cells, and B-cells (non-linear relation).Karmaus et al.(2005)Occupational 22 μg/dL: <30 yrs old23.0 μg/dL: 30–39 yrs old24.1 μg/dL:$40 yrs oldEmployees of Pb storage batteryfactories in Korea554 Men52 WomenSerum IgE higher when BLL >30 μg/dL—Correlation of BLL with serum IgE.For employees less than 30 yrs old, IL-4 was lower when BLL >30 μg/dL.Heo et al.(2004)Environmental 3.47–49.19 μg/dLChildren 6–11 yrs of age30 girls35 boysProximity to smelterIndirect (PHA) macrophage activation.NO production negatively associated with BLL.With proximity closest to smelter monocytes had increased superoxide anionproduction by indirect and direct activation (positive correlation with BLL–stronger for boys than girls).Pineda-Zavaleta et al.(2004)Environmental 2.56–43.69 μg/dL (mean9.52 μg/dL)38 preschool children (3–6 yrs ofage);35 controlsPercent of CD4+and CD4+CD+ cells decreased while CD8+increased.Zhao et al.(2004)OccupationalRange of 10.0–400.9 μg/dLMean = 88.3 μg/dLControls all below 10 μg/dLMale Pb-exposed workersPHA-mitogen response decreased; and IFN-gamma production increased.No effect on NK cytotox.Mishra et al.(2003)Environmental2.56–43.69 μg/dL(BLL mean of 9.52 μg/dL)96 females121 males(3–6 yrs old)IgG and IgM lower in high BLL group ($9.52 μg/dL).IgE greater in high BLL group (P < 0.10).No difference among males but femalesexposed to higher Pb had significantdecreases in IgG and IgMand increased in IgE.Correlation of BLL and serum IgE r = 0.48; P = 0.002.Sun et al.(2003)Occupational10–20 yr exposure (originalBLL mean 60 μg/dL; at time ofstudy BLL mean = 30 μg/dL)30 Pb workers from batterymanufacturing plant (43 males and21 females)Increased percentage of monocytes whilepercentage of B-cells, numbers oflymphocytes, monocytes, and granulocytes decreased.Sun et al.(2003)Occupational 74.8 ± 17.8 μg/dL vs. 16.7 ±5.0 μg/dL for controls25 male storage battery workersexposed >6 mo; age 33 ± 8.5 yrsDecreased blood hemoglobin, TCD4+cells, IgG, IgM, C3 and C4 complimentproteins.Increased zinc protoporphyrin.Impaired neutrophil chemotaxis and random migration.Basaran andUndeger(2000)

# AX5-148Table AX5-9.1 (cont’d). Studies on LeadExposure and Immune Effects in HumansNature ofExposureDose or Blood Lead Levels(BLLs)Sample PopulationReported EffectsReferenceEnvironmental1.7–16.1 μg/dL(Range in <3 yr old group)1561 children and adults in high Pbcommunity480 controls6–35 mo:increased IgA, IgG, IgM, number and proportion of B lymphocytesdecreased proportion of T-lymphocytes especially true when BLL > 15 μg/dL>3 yrs of age–no differences.Sarasua et al.(2000)EpidemiologicalstudyBlood Pbs from 1–45 μg/dLUrban Children population inMissouri; 56% male279 children 9 mo–6 yr of ageCorrelation of blood Pb levels and serum IgElevels in Missouri children. Lutz, et al.(1999)Occupational BLL=39Range 15–55 μg/dL145 Pb exposed workers84 controlsNo major effects; only subtle effects.Elev. B cells elevated CD4+/CD45RA+ cells.Decr. Serum IgG.Pinkertonet al. (1998)Occupational Pb workers with BLL between7–50 μg/dL; mean 19 μg/dL71 male chemical plant workers vs.29 controlsT cell populations,Naïve T cells correlated positively withblood PB levels. Memory T cellsreduced with Pb.Sata et al.(1998)OccupationalExposed—Range of 38–100 μg/dL mean = 74.8 μg/dL;Controls 11–30 μg/dL mean =16.7 μg/dL (high controls!)25 Male battery plant workers vs.25 controlsAbsolute and relative numbers of CD4+ T cells reduced in exposed group.IgG, IgM C3 and C4 serum levels all lower in workers.Undeger et al.(1996)OccupationalBLL 12–80.0 μg/dL33 male workers in a storagebattery plantNo changes in serum Igs of PHAresponse of PBMC. Queiroz et al.(1994)Occupational Maleshigh BLL$25 μg/dLlower BLL <25 μg/dLcontrol BLL#10 μg/dL51 Firearms instructors (high andlower) vs. controlsT cell phenotypes and response—Pb reducedrelative CD3+ cells and relative andabsolute CD4+ cells also reduced PHA (high Pb)and PWM mitogen responses,reduced MLR also(high Pb).Fischbeinet al. (1993)Occupational >60 μg/dL for group showingbest IgE effect2 groups of male workersoccupationally exposedIgE positively correlated with BLL.Horiguchiet al. (1992)OccupationalBLL 14.8–91.4 μg/dL39 male workers of storage batteryplant(4 yr mean exposure)Impaired neutrophil migration.Impaired nitroblue tetrazolium positive neutrophils.Greater for those exposed up to 1 yr than those with longer exposure “safe” levelsof Pb can still cause immunosuppression.Queiroz et al.(1993)In vitro207–1035 μg/LHuman lymphocytes from adults25–44 yrs of agePb associated with greater IgG production after stimulation with PWM–not dosedependent.Borella andGiardino(1991)

# AX5-149Table AX5-9.1 (cont’d). Studies on LeadExposure and Immune Effects in HumansNature ofExposureDose or Blood LeadLevels (BLLs)Sample Population Reported Effects ReferenceOccupational 33.2 μg/dL in Pb-exposedgroup2.7 μg/dL in controls10 Male workers in scrap metalrefinery vs. 10 controlsPMN chemotaxis reduced to 2 different chemoattractants.Valentinoet al. (1991)Occupational 10 Pb exposure workers vs.controlsWorker BLLs of 41–50 μg/dLNo controls >19 μg/dLConA-generated suppressor cell production—increased.Some other cellular parameters unchanged.Cohen et al.(1989)Occupational Blood Pbs 64 μg/dLRange 21–9039 male workers in Pb exposedgroupPHA response of lymphocytes from workers decreased. Alomran andShleamoon(1988)Occupational Comparison of workers with25–53 μg/dL vs. controls with8–17 μg/dLWorkers exposure to Pb No change in serum Ig levelsPHA response of cells orNK activity. Kimber et al.(1986)Environmental Near smelter BLLs variedseasonally 25–45 μg/dLControl area BLLs variedseasonally 10–22 μg/dLBoys and girls ~11.5 yrs old livingnear Pb smelting plantHigher BLL associated with: decreased)-amino levulinic acid dehydrogetase.Decreased IgM and secretory IgA.Inversely related to IgG.Wagnerovaet al. (1986)OccupationalWorkers (18–85.85.2 μg/dLBLL)controls (6.6–20.8 μg/dL BLL)73 workers vs. 53 controls Negative correlation of BLL and serum IgG and C3.Positive correlation ofBLL and saliva IgA.Ewers et al.(1982)Environmental 12 Afr.- American childrenBLLs 41–51μg/dL;7 controls BLLs 14–30 μg/dL12 African American preschoolchildren vs. 7 controlsNo difference in anti-tetanus antibody levels or in complement levels.Reigart andGraber (1976)

# AX5-150Table AX5-9.2. Effect of Lead on Antibody Forming Cells (In Vitro Stimulation)Species Strain/Gender Age EffectIn Vivo/ ExVivoLead Dose/ConcentrationDurationof ExposureReferenceMouse Various Adult↑AFC No 10 μM 5 days McCabe andLawrence (1991)Mouse VariousAdultAFC No changeYes10 mM in water8 wksMudziuski et al.(1986)Mouse CBA/J females Adult↑AFC primary responseNo100 μM5 daysWarner andLawrence (1986)Mouse BDF1females Adult↑AFC—T dependent antigenAFC—T independent antigen, nochange50 μg Pb acetate in water 3 wks Blakley andArcher (1981)Mouse CBA/J females Adult↑AFCYes0.08 mM and0.4 mM4 wksLawrence (1981a)Mouse CBA/J Adult↑AFC No10−5M5 daysLawrence (1981b)Mouse CBA/J females Adult↑AFC No10−4M1 hr preincubation Lawrence (1981c)Mouse Swiss males Adult↓AFCYes0.5 ppm tetraethyl Pb 3 wksBlakley et al.(1980)Mouse Swiss Adult↓AFCYes1300 ppm10 wksKoller and Roan(1980)Rat SD Neonate–Juvenile↓AFC (IgM)Yes25 ppm and 50 ppm3 wks prenatal and6 wks postnatalLuster et al (1978)Mouse Swiss Adult↑AFC–IgM↓AFC–IgGYes4 mg i.p. or oralSingle dose Koller et al.(1976)Mouse Swiss Adult↓AFC–IgM↓AFC–IgGYes13.75 ppm–1,375 ppm 8 wksKoller andKovacic (1974)

# AX5-151Table AX5-9.3. Studies Reporting Lead-induced Suppression ofDelayed Type Hypersensitivity and Related ResponsesSpeciesAgeStrain/GenderRouteLowest Effective DoseDurationof ExposureReferenceRatEmbryoSD femalesOral to Dam250 ppm (BLLat 4 wk = 6.75 μg/dL)5 wksChen et al. (2004)Chicken EmbryoCornell K femalesin ovo200 μgSingle injection E12 Lee et al. (2002)RatFetalCD femalesOral to Dam500 ppm6 daysBunn et al.(2001c)RatEmbryo–fetal F344 and CD females Oral to Dam250 ppm3 wksBunn et al.(2001b)RatEmbryo–fetal F344 femalesOral to Dam250 ppm (BLL = 34.8μg/dL at birth)3 wksBunn et al.(2001a)Chicken EmbryoCornell K femalesin ovo200 μg (BLL = 11μg/dL)Single injection E12 Lee et al. (2001)Mouse AdultBALB/c femalesOral512 ppm (BLL = 87μg/dL)3 wksMcCabe et al.(1999)RatEmbryo-fetal F344 femalesOral to Dam250 ppm Pb acetate5 wks (2 before, 3during gestation)Chen et al. (1999)RatEmbryo-fetal F344 femalesOral to Dam250 ppm Pb acetate5 wks (2 before, 3during gestation)Miller et al.(1998)Goat AdultFemalesGastric intubation 50 mg/kg Pb acetate6 wksHaneef et al.(1995)RatAdultWistar malesOral6.3 m mol kg-18 wksKumar et al.(1994)Mouse AdultSwisss.c.0.5 mg/kg/dShortest = 3 daysjust prior tochallengeLaschi-Loquerieet al. (1984)RatNeonatal/ Juvenile CD femalesOral25 ppm Pb acetate (BLL= 29.3 μg/dL)6 wksFaith et al. (1979)Mouse Adult BALB/c i.p.0.025 mgPb acetate30 daysMuller et al.(1977)

# AX5-152Table AX5-9.4. Effect of Lead on Allogeneicand Syngeneic MixedLymphocyte ResponsesSpecies Strain/Gender AgeProliferationEffectsIn Vivo/Ex VivoLead Dose/ConcentrationDurationof ExposureReferencesMouse C57Bl/6 andBALB/cAdult↑Allo-MLRNo0.1 μM4 days McCabe et al. (2001)Rat Lewis males Adult↑Allo-MLR↑Syngeneic-MLRNo50 ppm Pb acetate4 days Razani-Boroujerdi et al.(1999)Mouse CBA/J females Adult↑Allo-MLR No 10−6–10−4M5 days Lawrence (1981b)Mouse CBA/J females Adult↑Allo-MLRYes0.08 mM and 0.4 mM4 wks Lawrence (1981a)Mouse DBA/2J males Adult Allo-MLR nosignificant changeYes13, 130 and 1300 ppm10 wks Koller and Roan (1980)

# AX5-153Table AX5-9.5. Effect of Lead on Mitogen-induced Lymphoid ProliferationSpecies Strain/ Gender Age Proliferation EffectsIn Vivo/Ex VivoLead Dose/ ConcentrationDurationof ExposureReferencesHumanCAdult↓PHA Yes Not available Occupational Mishra et al. (2003)Mouse TO males Adult↓ConA↓LPSYes 1 mg/kg daily 2 wks Fernandez–Carbezudo et al.(2003)Mouse SeveralAdult PHA stimulation NochangeNo 25 μM3 daysMcCabe et al. (2001)RatLewis and F344malesAdult↑ConA↑LPSNo 25 ppm3 daysRazani–Boroujerdi et al. (1999)Mouse CBA/JAdult LPS No changeNo 10 μM3 daysMcCabe and Lawrence (1990)RatAP strain males Adult PHA Nochange Yes 100 ppm and 1,000 ppm2–20 wksKimber et al. (1986)Mouse CBA/J females Adult ConALPSNo changeNo 10−4M2 daysWarner and Lawrence (1986)Mouse BDF1 females Adult↑ConA↑PHA↑Staph A enterotoxinLPS no changeYes0–1,000 ppm3 wks Blakley and Archer (1982)Rat SD males Adult↑ConA↑PHA↑LPSYes 1% Pb acetate in diet 2 wks Bendich et al. (1981)Mouse CBA/J females Adult PHA no change↓LPS (high doses only)Yes 10 mM4 wksLawrence (1981a)Mouse CBA/J females Adult ConA, PHA no change↑LPSNo10−6–10−4M2.5 days Lawrence (1981b)Mouse CBA/J females Adult ConA, PHA no change↑LPSNo10−6–10−4M2–5 daysLawrence (1981c)

# AX5-154Table AX5-9.5 (cont’d). Effect of Lead onMitogen-induced Lymphoid ProliferationSpecies Strain/ Gender Age Proliferation EffectsIn Vivo/Ex VivoLead Dose/ ConcentrationDurationof ExposureReferencesMouse C57 Bl/6 males Adult↓PHA↓ConALPS No changeYes 1,300 ppm 8 wks Neilan et al. (1980)Rat SDfemales Neonatal–Juveniles↓PHA↓ConAYes 25 ppm6 wksFaith et al. (1979)Mouse BALB/c Adult↑LPS No10−5–10−3M3 days Gallagher et al. (1979)Mouse Swiss males Adult↓PHA↓PWMYes 2,000 ppm30 daysGaworski and Sharma (1978)Mouse Swiss males Adult↑PHA↑PWMNo 0.1 mM–1.0 mM 2–3 days Gaworski and Sharma(1978)Mouse CBA/J Adult↑LPSYes 13 ppm18 moKoller et al. (1977)Mouse BALB/cAdult↑LPS No 10−5–10−3M2–3 days Shenker et al. (1977)

# AX5-155Table AX5.9.6. Pattern of Lead-induced Macrophage ImmunotoxicitySpeciesStrain/GenderAge FunctionIn Vivo/Ex VivoLowest EffectiveDoseDurationof ExposureReferencesNitric OxideHuman Both genders Juvenile↓NOYes NKPineda-Zavaleta et al.(2004)Rat CD males Embryo↓NOYes 500 ppm6 daysBunn et al. (2001c)Chicken Cornell Kstrain femalesEmbryo↓NOYes 10 μgOne injection(E5)Lee et al. (2001)Mouse BALB/cfemalesAdult↓NO No20μg/mLone lower dose↑NO2 hrsKrocova et al. (2000)Chicken HD-11 cellline-↓NONo 4.5 μg18 hrsChen et al. (1997b)Mouse CBA/JfemalesAdult↓NONo 1.0 μg4 daysTian and Lawrence (1996)Mouse CBA/JfemalesAdult↓NONo 0.625 μM4 daysTian and Lawrence (1995)Reactive Oxygen IntermediatesHuman Associated inmalesJuvenile↑ROIYes NKNKPineda-Zavaleta et al.(2004)Rat Not indicated NK↑ROINo 240 μM3 hrsShabani and Rabbani(2000)Mouse BALB/cfemalesAdult↑ROIYes 1.5 mg/kg diet 30 daysBaykov et al. (1996)Rabbit New Zealandwhite malesAdult↑ROI Yes31μg/m3inhaled 3 daysZelikoff et al. (1993)

# AX5-156 

# ANNEX TABLES AX5-10

# AX5-157Table AX5-10.1. Hepatic Drug MetabolismConcentration Duration Species Blood LeadEffectsaReference2 daysIn vitro, ratmicrosomes—Triethyl Pbchloride, 0–3.0mg/kg b. wt.In vitro, 0.0–3.0mM triethyl PbNot specified In vivo, ratmicrosomes—Triethyl Pb increased microsomal N-oxygenation in vivo anddecreased microsomal C oxygenation by in vitro treatment. Eithertreatment thus gave rise to an increase in the N-oxygenation/C-oxygenation ratio, which may lead to tumor potentiation.Odenbro andArhenius (1984)5 or 10 μmol/100gb. wt. Pb nitrate;i.v.36 h Male Fischer344 rats— Pb decreases phase I components (liver microsomal cyt.P-450), andincreases Phase II components (GST, DT diaphorase etc). Livercytosol in treated animals had a polypeptide that cross-reacted withGSTP.Roomi et al.(1986)5, 10, 50 mg Pbacetate kg!1b. wt.Multipledurations(15 days,2 and 3 mo)Female albinorats— Over all induction of cyt-p—450 and b5 in liver, long-term increasein liver GST and GSH.Nehru andKaushal (1992)100 μmol/kg; i.v.Pb acetate24 hMale Fischer344 rats— Decrease in total CYP amount, selective inhibition of CYP1A2 anddecrease in the expression at m-RNA and protein level, induction ofplacental form of glutathione s-transferase (GST-P).Degawa et al.(1994)100 μmol/kgPb nitrate; i.v.9 h before or 6 hafter2-methoxy-4-aminoazobenzene(2-Meo-AAB)Male Fischer344 rats—Male fisher rats treated with different metal ionsCPb nitrate, nickelchloride, cobalt chloride or cadmium chloride exhibited decreasedtotal CYP amount in liver microsomes. However, only Pb reducedthe levels of the mRNA and protein of CYP 1A2 induced with 2-methoxy-4-aminoazobenzene (2-Meo-AAB) and decreased themicrosomal activity (Per CYP), Pb also induced placental form ofGlutathione, a marker enzyme for preneoplastic lesion.Degawa et al.(1995)100 μmol/kg; i.v.Pb acetate24 hMale F 344 rats — Inhibition of CYP1A mRNA(s) by Pb nitrate is by aromatic amines,not by aryl hydrocarbons.Degawa et al.(1996)100 μmoles /kg;i.v.Multipledurations (3, 6,12, 24, and 36 h)Male Wistarrats—Stimulation of TNFαpreceding hepatocyte DNA synthesisindicates a role for it in liver cell proliferation.Pb nitrate enhances sensitivity to bacterial LPS, in hepatocytes.Shinozuka et al.(1994)

# AX5-158Table AX5-10.1 (cont’d). Hepatic Drug MetabolismConcentration Duration Species Blood LeadEffectsaReferenceSingle 0.33 mg/kg-1 Pb nitrateMultipledurationsMale Wistar rats — Pb confers protectionagainst the CCL4 induced hepatotoxicity asevident by marked reduction in serum Alanine aminotransferase(AST) and aspartate aminotransferase (AST) and this protection isnot associated with themitotic response of Pb.Calabrese et al.(1995)Pb acetate, 75 mgof Pb2+/kg,intraperitonialMultiple analysesup to 30 hC57BL/6 malemice— The decrease in P-450 as a resultof Pb poisoning occurs at twolevels. (1) A mechanism unrelated to heme, where Pb interfereswith P-450 in 2 ways. (2) A mechanism dependent on heme, inwhich Pb inhibits heme synthesis.Jover (1996)0–10!6M Pb nitrate3 days Fish hepatomacell linePLHC-1— Effect of heavy metals Cu(II), Cd(II), Co(II), Ni(II), Pb(II), andZn(II), on Cytochrome induction (CYP1A) induction response andEthoxy resorufin-o-deethylase (EROD) activity.All metals had a more pronouncedeffect on EROD activity thanCyp1 A protein. The rank order of the metal inhibition on EROD isCd(II) > Ni(II) > Cu(II) > Co(II) = Zn(II), Pb(II), Cd(II) and (Cu).May affect Cyp1 A system of the fish liver at low concentrationsthrough the direct inhibition of CYP 1A enzyme activity.Bruschweileret al. (1996)DT Diaphoraseactivity 0–125mg/kg Pb acetate,Pb nitrateTime courseexperiments100 mg/kg Pbacetate, i.p.24 h–120 h Male Wistar rats — Pb acetate and nitrate induce DT diaphorase activity which isinhibited significantly by Dil acalcium antagonist, showing thatthese changes are mediated by intracellular calcium changes. Pbacetate induces DT diaphorase activity with out thymus atrophy andhence was suggested to be a monofunctional inducer as against theMethyl cholanthrene inducedDT diaphorase activity.Arizono et al.(1996)Cell viabilityassays 0–30 μM,for all other As ,Pb, Hg, 5 μM, Cd,1 μM24 h in generaland for ERODassays by PAHs24–72 hPrimary humanhepatocytes— The effect of metals on PAHinduced CYP1A and 1A2 as probedby Ethoxy resorufin o- deethylaseactivity has demonstrated, metals-Arsenic, Pb, mercury and cadmium decreased CYP1A1/ A2expression by polycyclic aromatic hydrocarbons depending on thedose, metal and the PAH. Arsenic was most effective, followed byPb, cadmium, and mercury. Cellviability was decreased by 20–28% by metals.Vakharia (2001)

# AX5-159Table AX5-10.1 (cont’d). Hepatic Drug MetabolismConcentration Duration Species Blood Lead EffectsaReference10–100 μM,in vitro24 h Murinehepatoma cellline— Effect of heavy metals on Aryl hydrocarbon regulated genes—metals alone did not induce a significant change in the cyp1a1activity and protein levels but increased its m-RNA expression.AHR ligand-mediated induction ofcyp1a1 activity and protein wasobserved by all the metals. Pre and post translational modulation inthis regulation have been implicated. These results demonstratethat the heavy metals differentially modulate the constitutive andthe inducible expression of AHR regulated genes.Korashy andEl-Kadi (2004)5 and 10μmoles/100 g ofb.wt, single i.p— Wistar Rat — Pb nitrate induced the expression of Placental form of Glutathionetransferase along with liver cell proliferation. The biochemicallesions induced by Pb under these conditions were similar to that ofhepatic nodules.Roomi et al.(1987)100 μmoles/100 gb. wt. Pb nitrate,single injection, i.v.Animals weresacrificed at1, 2, 3, 4, and15 daysWistar rats — Acute Pb treatment results in induced activity of Gamma-glutamyltranspeptidase, induced GSTP, a typical marker of pre neoplasticlesion in most hepatocytes. Pbalso inhibited liver adenylatecyclase activity 24h postexposure.Columbano et al.(1988)100 mg/kg i.p.,single exposureMultiple analyses0–96 hMale DDYstrain mice— Pb decreased Glutathione content and decreased Glutathione s-transferase activity that is independent of Glutathione levels.Nakagawa et al.(1991)100 μmol/kg bodywt, i.v70 h Male SpragueDawley rats— Acute Pb nitrate treatment caused a significant increase of GSTactivity in liver and kidney. While in liver the activity increase ismainly due to isozyme GST 7-7,in kidney it is through theinduction of all the isozymes.Planas-Bhone andElizalde (1992)100 μmol/kg b. wt.,intra cardiacMultiple timepoint analysesstarting 6 days to5 moMale andfemale Wistarrats— Intracardiac administration of Pb acetate results in elevation ofglutathione transferase (GST) in Kupffer cells, the early response toGST.Yp was observed in sinusoidal cells and had a later patchyresponse in the expression of GST.Yp Yp in hepatocytesBoyce and Mantel(1993)10 μmol/100g b.wt., Pb nitrate, i.v.single doseAnalyses atmultiple timepoints 0–10 daysMale Fischer344 young adultrats— Glutathione transferase P1-1 is induced significantly by a singleintravenous dose of Pb nitrate through increased transcription andmodulations at post transcription and translational levels.Koo et al. (1994)

# AX5-160Table AX5-10.1 (cont’d). Hepatic Drug MetabolismConcentration Duration Species Blood Lead EffectsaReferencePb nitrate,100 μm/kg i.p,3 times every 24 h48 h —Pb acetate100 μM/kg.0.5–24 hTransgenic ratswith 5 differentconstructshaving GST-Pand/orchloromphenical acetyltransferasecodingsequence.—GSTP (placental GST), is regulated by Pb at transcriptional level.GST-P enhancer (GPEI), is an essential cis-element required for theactivation of the GST-P gene by Pband is involved in the activationregardless of the trans-activators involved. GPEI element consistsof two AP-1 binding sites. Activation of GST-P gene by Pb ismediated in major part by enhancer GPEI, which may involve AP-1activation partially.10 nM Pb nitrate 24 h beforetransfection withECAT deletionmutant, every 24h there after till48 h aftertransfectionNRK Kidneyfibroblasts— Pb induces GST-P in NRK normal rat kidney fibroblast cell line.Suzuki et al.(1996)10 mg Triethyl Pb,i.p. single doseAnalyses atmultiple durations(3, 4, 7, 10, or 14days)Fischer 344 rats — Decreased liver Glutathione s-transferase (GST) activity and lowerlevels of several hepatic GST.Increase in quinone reductase activity by day 14 in liver.Daggett et al.(1997)114 mg Pbacetate/kg b. wt. i.pSingle (0.5–12 hgroup) or multiple(72 h and 7 daysgroup) exposureSprague Dawley — Pb exposure resulted inhepatic Glutathione (GSH) depletion andincreased malondialdehyde (MDA) production.Daggett et al.(1998)A. 1.5–3.0 mg/kgwtTriethyl Pb (TEL)i.p.2 exposures for48 hFemale Wistar — Pretreatment of rats didnot affect the liver microsomal Oestradiol-17βmetabolism or the content of cytochrome P-450 andcytochrome b5.B. 0.05–0.5, TELto liver microsomalfractions30 minincubationsLivermicrosomesfrom femaleWistar rats— TEL at 0.05 mM significantly reduced 17β-hydroxy steroidoxidation and at concentration of 0.05 mM decreased 16α-hydroxylation.Odenbro andRafter (1988)

# AX5-161Table AX5-10.1 (cont’d). Hepatic Drug MetabolismConcentration Duration Species Blood Lead EffectsaReference50 mg/kg,intragastric8 wks Male AlbinoWistar rats— Accentuation of liver membrane lipid peroxidation. significantinhibition of liver antioxidant enzymes. Reduced ratio of reducedglutathione(GSH) to oxidized glutathione (GSSG),Sandhir and Gill(1995)Abbreviationsb. wt.—body weightaCYP—Cytochrome P-450GSH—GlutathioneGSSG—Oxidized glutathioneTEL—Triethyl leadCCL—Carbon tetrachlorideGSTP—Placental glutathione transferaseMDA—MalondialdehydeCu—CopperCd—CadmiumAl—AluminumZn—ZincPb—LeadNi—NickelTNFα—Tumor necrosis factorALA—Alanine aminotransferasePAH—Polycyclic aromatic hydrocarbonsLPS—Lipopolysaccharides

# AX5-162Table AX5-10.2. Biochemical and Molecular Perturbations in Lead-induced Liver TissueConcentrationDurationSpeciesBlood LeadEffectsaReferencePb-diethyldithiocarbomatecomplex, Pb (DTC) 2,or Pb acetate 0.033–10 μM0.5–20 hPrimary hepatocytes — Effect of interactionsbetween Pb and diethyl dithiocarbomate (DTC) on theenzymeδamino levulinic acid dehydratase in primary hepatocytes.Lipophilic Pb (DTC)2 caused a more rapid and stronger inhibition of ALADactivity than Pb acetate.Pb uptake is higher and more rapid with Pb (DTC)2 than Pb acetate. Thisincreased inhibition of ALAD activity by Pb (DTC)2 might be due to facilitated cellular transport in the complexed formresulting in higher cellular concentrations of Pb.Oskarsson andHellström-Lindahl(1989)——Primary rathepatocytes— DTC decreases cellular effects ofPb and Cd despite unchanged/ evenslightly increased concentrationsof the metals. Hepatic ALAD wassignificantly inhibited in cells treated with Pb Ac and Pb (DTC)2.Hellström-Lindahland Oskarsson(1990)——DBA and C57 mice — DBA mice(with a duplication of the ALAD gene accumulated twice theamount of Pb in their blood and had higher Pb levels in liver and kidneythan mice with the single copy of thegene (C57), exposed to the same oraldoses of the Pb during adult hood. Blood Zinc protoporphyrin (ZPP)increased with Pb exposure in C57 mice and were not affected in DBAmice.Claudio et al.(1997)100 μmol/kg b. wt.i.v. single doseSingle dose,analyses performed12, 24, 48, 72, 96and 168 hMale Wistar AlbinoRats— First in vivo report showing association between Pb induced liverhyperplasia, Glucose-6-phosphate levels, and cholesterol synthesis.Pb treatment increased hepatic de novo synthesis of cholesterol as evidentby increased cholesterol esters and increase of G-6-PD to possibly supplythe reduced equivalents for de novo synthesis of cholesterol. Changes inthese biochemical parameters wereaccompanied by liver hyperplasia.Dessi et al. (1984)Pb nitrate, Single dose100 μmol/kg b. wt.0–168 hMale Wistar rats— Pb nitrate induces hepatic cell proliferation followed by reabsorption ofexcess tissue with in 10–14 days. The proliferation was correlated withhepatic denovo synthesis of cholesterol, stimulation of hexosemonophosphate shunt pathway and alterations in serum lipo proteins.Pani et al. (1984)Pb nitrate—Wistar rats— Pb nitrate induces multiple molecular forms of Glucose-6- phosphatedehydrogenase with an increase of band 3 and a concomitant increase ofband 1, shifting from the pattern induced by fasting with an increase inband 1.Batetta et al. (1990)

# AX5-163Table AX5-10.2 (cont’d). Biochemical and Molecular Perturbations in Lead-induced Liver TissueConcentrationDurationSpeciesBlood LeadEffectsaReferencePb nitrate, single i.v.10 μM/100 g b. wt.Multiple time points24–72 h and20 daysMale Wistar rats— Pb nitrate exposure resultsin complete loss of liver glycogen between 24and 48 h, which was replenished and was found in excess in treated liverhepatocytes by 20 days. Glycogensynthase and glycogen phosphorylaseactivities were diminished by 24 h and return to normal values by day 20.The pentose phosphate enzymes were upregulated, which coincided highlywith the increase in mitotic rate.Overall Pb nitrate induces drasticalterations in hepatic carbohydrate metabolism along with increased hepaticcell proliferation.Hacker et al. (1990)——Rats— Pb acetate induced mitotic response much more effectively in renalepithelial cells than liver cells (675 fold less).Calabrese andBaldwin et al.(1992)10 or 20 mg/kg as Pbacetate, subcutaneousOnce a wk for5 wksOccupationallyexposed workersRatsPb-exposedworkers:0.24–30 nM/mLControl rats:0.18 nM/mL10 mg Pb/kg:2.42 nM/mL:20 mg Pb/kg:3.82 nM/mLPb induces lipid peroxidation in serum of manual workers, while bloodsuperoxide dismutase (SOD) activity decreased. Similar phenomenon wasobserved with rats that were subcutaneously injected with Pb acetate.At higher than 20 μM concentration, Pb in untreated microsomes increasedNADPH dependent lipid peroxidation.Ito et al. (1985)100 μM/kg b. wt Pbnitrate, i.v36 h postexposure Male Wistar Albinorats— Endogenous source of newly synthesized cholesterol together with increaseof HMP shunt enzyme activities is essential for hepatic cell proliferation byPb nitrate.Dessi et al. (1990)2000 ppm Pb acetatein diet.3 wksArbor Acres malechicks— Liver non protein sulphahydryl (NPSH) and glutathione (GSH) wereincreased upon Pb exposure. The concentrations of liver glutamate, glycine,and methionine were also elevated upon Pb exposure.Mc Gowan andDonaldson et al.(1987)0–4000 ppmPb acetate, oral21 daysArbor Acre broilerchicks— Pb increases tissue peroxidation via a relative increase of 20:4 fatty acids.Decrease in the hepatic ratio of 18:2/20:4 might be specific to Pb toxicity.Donald andLeeming (1984)

# AX5-164Table AX5-10.2 (cont’d). Biochemical and Molecular Perturbations in Lead-induced Liver TissueConcentrationDurationSpeciesBlood LeadEffectsaReferenceSodium vanadate,30 mg/kgsubcutaneous in mice30 mg/kg b.wt, i.p. inrats0.5 mMAcute studies,24 h—Vanadium sulphate indrinking water forchronic treatmentChronic studies10 wksMale Swiss-Webster miceMale SpragueDawley Rat—Sodium orthovandate increases lipid peroxidation in kidneys of mice andrats. Malondialdehyde (MDA) formation increased 100%, with in 1 hafter injection.In both rat and mice, no significant increase in lipid peroxidation wasobserved in brain, heart, lung, and spleen.Chronic exposure to vanadium, throughmaternal milk and drinking waterfor 10 wks increased MDA formation and lipid peroxidation in kidneys.Donaldson et al.(1985)250–2000 ppm Pbacetate in diet19 daysArbor Acre broilerchicks—Dietary Pb consistently increased liver arachidonic acid, thearachidonate/linoleate ratio andhepatic non-protein sulfhydrylconcentration. Hepatic microsomalfatty acid elongation activity wasdecreased by Pb over all. These results demonstrate that changes in theprecursors and mechanisms involvedwith eicosanoid metabolism are notalways reflected in tissue concentrationsof leukotriens and prostaglandin.Knowles andDonaldson et al.(1990)1.25–20.00 mg/L Pbnitrate, oral30 daysFresh water fish—Pb accumulation in theliver and other tissue increased in a dose dependentmanner up to 5mg/L, exposure to sublethal concentration (5 ppm) of Pbreduced the total lipids, phospholipids,and cholesterol levels in the liverand ovary. Pb nitrate may affect the fecundity of fish by altered lipidmetabolism.Tulasi et al. (1992)250 mg/L of Pb as Pbacetate, oral5 wks of exposurefollowed by 4 wksof recoveryWeanling femaleSD rats—Effect of weight loss on body burden of Pb: weight loss increases thequantity and concentration of Pb inthe liver even inthe absence ofcontinued exposure.Han et al. (1996)35–70 mg, Pb intragastricOne or two times awk/7 wksMale Buffalo rats Control: 4.6 μg/dLPb 35 mg/kg:16.8 μg/dLPb 70 mg/kg:32.4 μg/dLDecrease in plasma cholesterol, and HDL fraction, increase in serumtriglyceride, atrophy of the elastic fibers in the aorta.Skoczynska et al.(1993)AbbreviationsaCYP—Cytochrome P-450ALAD—Aminolevulinic acid dehydratasGSH—Reduced GlutathioneZPP—Zinc protoporphyrinHMP—Hexose monophosphate shunt pathwayb. wt.—body weight

# AX5-165Table AX5-10.3. Effect of Lead Exposure on Hepatic Cholesterol MetabolismConcentrationDurationSpeciesBlood LeadEffectsaReference100 μmol/kg body wt,i.v. Pb nitrateMultiple durations0, 3, 6, 12, 24, and48 hMale SpragueDwaley (SD) rats—Pb nitrate, activates the expression of the SREBP-2 and CYP 51 genewith out decreasing the serum cholesterol level.Kojima et al. (2002)100 μmol/kg body wt,i.v. Pb nitrateMultiple durations0, 1, 3, 6, 12, 18, 24,48, and 72 hMale SpragueDawley (SD) rats—Pb nitrate effects on hepatic enzymes involved in cholesterol homeostasis.Demonstrated for the first time sterol independent gene regulation ofcholesterol synthesis in Pb nitrate treatment.Kojima et al. (2004)0.05 mg/kg bodywt/d. Pb acetate,subcutaneous, with orwithout cadmiumacetate 0.025 mg Pbacetate/kg body wt/dPreexposure for5–7 days, gestationthrough lactationFemale CharlesFoster rats—Pb and cadmium accumulated in the livers of metal treated pregnant andlactating rats. Hepatic steroid metabolizing enzyme 17-β-hydroxy steroidoxidoreductase and UDP glucaronyl transferase were decreased and thehepatic Cytochrome P-450 content was reduced by the metal exposure.Pb and cadmium alter liver biochemical parameters, however, combinedexposure had no intensifying effect on liver parameters. Whenadministered together on similar concentration basis, the major effectsare mediated by cadmium.Pillai and Gupta(2004)300 mg/L Pb acetate,oralGestation throughlactation analysesdone at day 12 andday 21 postnatalFemale WistarratsControl: 1.13 μg/dLPb-exposed12 days PN: 22.01μg/dL21d PN: 22.77 μg/dLIn neonates, decrease in liver Hb, iron, alkaline and acid phosphataselevels. Protein, DNA and lipid total amounts were reduced and hepaticglycogen content was reduced. Pb intoxication of mothers in gestationand lactation results in alterations in the hepatic system in neonatesand pups.Corpas et al.(2002b)aCYP—Cytochrome P-450bwt.—body weight

# AX5-166Table AX5-10.4. Lead, OxidativeStress, and Chelation TherapyConcentration andCompound Duration Species BloodLeadEffectsReferencePb acetate, 50 mg/kgb.wt, intragastric8 wks Male AlbinoWistar rats— Pb induces accentuation of membranelipid peroxidation in liver by thechanges (decrease) in theactivities of several antioxidant enzymes such asSOD, Catalase, GPx and Glutathione reductase. Pb exposure also causeda reduction in GSH/GSSG ratio (reduced to oxidized Glutathione).Sandir and Gill(1995)2,000 ppm, Pbacetate, Diet5 wks Male Fisher 344rats, young andoldYoung control:<1 μg/dLYoung Pb-exposed:38.8 μg/dLOld control:<1 μg/dLOld Pb-exposed:21.7 μg/dLEffect of Pb on lipid peroxidation inyoung vs. adult rats– Liver GSSG andmalondialdehydehyde levels were significantly higher in young rats thanadult rats. Blood Pb levels werehigher in young exposed animals ascompared to adults. In young, Pb exposed animals, Pb induced oxidativestress was more pronounced particularly in liver tissue.Aykin-Burns et al.(2003)0.1–1.0 μM—Lipid peroxidation as indicated by Malondialdehyde accumulationupon exposure to various redox-sensitive metals in cultured rathepatocytes and hepatocytes loaded withα-linolenic acid indicated thatAl, Cr and Manganese, Ni, Pb and tin did not effectively induce lipidperoxidation in these cells.– The induction was the highest in ferrous iron treated cells comparedto other metals (Cu, Cd, V, Ni).FeSO4, VCl3, CuSO4,CdCl2, CoCl2, AlCl3,CrCl3, MnCl2, NiSO4,Pb(NO3)2, SnCl2,culture medium9 h—LAN—bovine serumcomplex 0.8 mM inculture mediumAdditional 12 hincubationRat liverhepatocytes.Normal and LANloaded—With any metal, the induction was higher inα-linolenic acid treated cells.Iron and V induced cell injury in LAN loaded cells was prevented byaddition of DPPD. Cd was a weak inducer of lipid peroxidation underthese conditions.Furono et al. (1996)5 mg kg−1, Pbacetate, i.p., singledose followed bytherapy with chelatingagentsAnalyses after6 days of treatmentDMSA, Mi-ADMSA at multipletimes (0.5, 24 hr,4th and 5th dayafter Pb treatWistar 6 days oldsuckling rats—Treatment with DMSA and Mi- ADMSA showed Mi-ADMSA to bemore effective in reducing the skeletal, kidney and brain content of Pb.However there was no difference inreducing the liver Pb contentbetween the two compounds.Blanusa et al.(1995)

# AX5-167Table AX5-10.4 (cont’d). Lead, Oxidative Stress, and Chelation TherapyConcentration andCompoundDuration Species BloodLeadEffectsReference550 ppm Pb acetate,oral DMSA treatment.(A) Pb for 35 +21 days(B) Pb 35 days andPb and DMSAfor 21 days(C) Pb 35 days andDMSA for21 days(D) Acedified Di H2Ofor 35 days andDi water for21 days6–7 Wk old maleSprague-DawleyratsPb-exposed:50 μg/dLPb 35 days: Rangedfrom 5–20 μg/dL +DMSA from 0–240 μg/kg/dDMSA reversed the hematological effects of Pb, decreased the blood,brain , bone, kidney and liver concentration and produced marked Pbdiuresis, even when challenged with ongoing Pb exposure.Pappas et al. (1995)Pb acetate Dose toachieve blood Pblevels of 35–40 μg/dL.Biweekly doseadjustments, oralfollowed by treatmentwith chelator.1 yr, chelator fortwo successive19 day periodfollowing Pbexposure.Infant rhesusmonkeysPb-exposed:35–40 μg/dLSpecific emphasis on the beneficial effects of succimer treatment tocessation of Pb exposure. Thesedata demonstrated that succimerefficiently reduces blood Pb levelswhich does not persist beyond thecompletion of treatment. They alsodemonstrate the relative benefit ofeliminating Pb exposures , which serves to underscore the importance ofprimary prevention of Pb exposure. Neither DMSA treatment nor thecessation of Pb exposure were beneficial in reducing skeletal Pb levels.Smith et al. (2000)5 mg Pb kg−1, i.p Pbacetate followed bychelators for varioustime points.Analyses at Day 5 Suckling Wistarrats—Meso—DMSA is the treatment of choice for acute Pb poisoning in infantscompared to EDTA and Rac-DMSA.Kostial et al. (1999)50 mg/kg Pb as Pbnitrate, i.p, twoinjections, 16h apart50% Ethanol, 0.5 mL,two injections, 16 hapart24 hMale Albino rats—S-Adenosyl methionine confers protection against alterations in severalparameters (ALAD, GSH, MDA) indicative of lipid peroxidation in blood,liver and brain in Pb and acute Pb and ethanol exposed animals as well asthe organ concentration of Pb.Flora and Seth(1999)0.1% Pb acetate indrinking water withand without SodiumMolybdate, i.p4 wksMale Albino rats Pb-exposed:39 μg/dLPb + chelators:4.6–13.1 μg/dLSodium molybdate significantly protectedthe uptake of Pb in blood, liverand kidney. The treatment with molybdate also restored the Pb inducedinhibited activity of bloodδ-aminolevulinic acid dehydratase and theelevation of blood Zn protoporphyrin , hepatic lipid peroxidation andserum ceruloplasmin.Flora et al. (1993)

# AX5-168Table AX5-10.4 (cont’d). Lead, Oxidative Stress, and Chelation TherapyConcentration andCompoundDuration Species BloodLeadEffectsReference20 mg/kg Pb acetate,i.p.3 days treatment Male Albino rats — Significant Pb induced inhibition of hepatic heme synthesis associatedwith decline of mixed function oxidases, depletion in anti oxidants suchas vitamin C. Oral supplementation with vitamin C confers protectionagainst toxic insult by reversing these parameters.Vij et al. (1998)1.5 mg/per bird /d 30 daysBroiler chicken—Pb-induced inhibition of 5' mono deiodinase (5'- D) activity in chickensappeared to be mediated through the lipid peroxidative process.Chaurasia et al.(1998)1. Pb acetate10 mg/mL/kg (a)2. Ethanol 1 g/4 mL/kg (b)3. a + b = (c)4 a + zinc 10 mg/4 mL/kg + lysine25 mg/4 mL/kg(d)5. b + 2n + lysine asin days, oral6. a + b + Zn +lysine as in days5 days/wk/8 wk Male Albino rats Control: 1.75 μg/dL1. 47.23 μg/dL2. 2.08 μg/dL3. 45.37 μg/dL4. 34.19 μg/dL5. 1.84 μg/dL6. 46.69 μg/dLInfluence of lysine and zinc administration on the Pb-sensitivebiochemical parameters and the accumulation of Pb during exposure toPb. (1) Pb exposure inhibited blood ALAD activity. Serum enzymesincreased blood and tissue Pb levels. (2) Decreased blood and hepaticglutathione. Some of these effects were enhanced with co-exposure toethanol. Simultaneous administrationof lysine and zinc reduced tissueaccumulation of Pb and most of thePb-induced biochemical alterationsirrespective of exposure to Pb alone or Pb and ethanol.Tandon et al. (1997)1300 ppm Pb acetatein drinking water5 wksC57BL/6 mice—Pb treatment resulted indepletion of GSH, increased GSSG and promotedMalondialdehyde (MDA) production inboth liver and brain samples.DMSA or N- acetyl cysteine (NAC) treatment resulted in reversion ofthese observations. DMSA treatment resulted in reduced Pb levels inblood, liver and brain, where as treatment with NAC did not reduce theselevels.Ercal (1996)2000 ppm of Pbacetate in drinkingwater5 wks followed bytreatment withsuccimer DMSA, orthiol agent NACFisher 344 malerats—Pb induces oxidative stress in RBC and these biochemical alterations arereversed by both a thiol antioxidant (NAC) as well as a chelating agentDMSA.Gurer et al. (1998)500 μM Pb acetate incells2000 ppm of Pbacetate in drinkingwaterCells—20 hAnimals 5 wksfollowed bytreatment withα-lipoic acidMale fisher ratsand Chinesehamster ovarycells—Pb induces oxidative stress.α-lipoic acid (LA)treatment significantlyincreased thiol capacity of cells and animals via increasing glutathionelevels and reducing Malondialdehyde levels, increased cell survival.LA was not effective against reducing blood or tissue Pb levels.Gurer et al. (1999)

# AX5-169Table AX5-10.4 (cont’d). Lead, Oxidative Stress, and Chelation TherapyConcentration andCompound Duration Species BloodLeadEffectsReference0–500 μM Pb acetate 6 hCHO cells and—2000 ppm of Pbacetate in drinkingwater for 5 wks5 wksTaurine1.1 kg/d6th wkFischer 344 rats Controls: 0.43 μg/dLPb-exposed:36.4 μg/dLPb + Taurine:33.8 μg/dLAntioxidant Taurine reversed theabnormalities associated with lipidperoxidation parameters such as increased. Malondialdehyde formationand decreased Glutathione and enhanced CHO cell survival. However,was not effective in reducing cell and tissue Pb burden in CHO cells andPb exposed Fischer rats.Gurer et al. (2001)1 mg Pb2+/kg B.wt ,i.p. Pb acetate4 wks, treatmentwith variousantioxidant in the5th wkIVRI 2 CQ rats—Pb exposure resulted in increased lipid peroxidation, with tissue specificchanges in liver. Treatment of exposed rats with ascorbic acid andα-tocopherol lowered the lipid peroxidation.Patra et al. (2001)Pb as acetate, 400 mgPb2+/mL, drinkingwater10 days—0.5 mg/mLL-methionine4 wks post-PbexposureKunming mice—L- methionine has an ameliorativeeffect on Pb toxicity–Methioninereduced the decrease inHb content and depressed body growth caused byPb. Treatment with dietary methione along with Pb decreased the MDAformation as opposed to Pb, moderately reversed the decreased ironcontent of the organs and decreased organ Pb content.Xie et al. (2003)100 μM/kg b.wt. Pbacetate,intramuscular, single3 and 24 hMale Albino rats—Pb exposure resulted in significant increases in acid and alkalinephosphatases, serum GOT and GPT, elevated liver and kidney lipidperoxidation and decreased antioxidant enzymes at 3 and 24 h afterexposure. Selenium administration prior to Pb exposure producedpronounced prophylactic effects against Pb exposure by enhancingendogenous anti oxidant capacity.Othman and ElMissiry (1998)100 μg/ Pb acetate,intra gastric, oral andintraperitoneal,treated with or without thiamin (25,50 mg/kg b.wt) and orCa EDTA (50 mg/kgB.wt3 daysCD-1 mice—Two times more whole bodyPb was retained by intraperitoneal injectionas compared to intragastric administration. Thiamin treatment increasedthe whole body retention of both intragastric and intraperitoneal Pb byabout 10%. Calcium EDTA either aloneor in combination with thiaminreduced the whole body retention of Pb by about 14% regardless of theroute of exposure. Regardless of the route Ca EDTA in the combinedtreatment reduced the relative retentionof Pb in both in liver and kidney.These studies indicate the combination treatment with thiamin and CaEDTA alters the distribution and retention of Pb in a manner which mighthave therapeutic application.Kim et al. (1992)

# AX5-170Table AX5-10.4 (cont’d). Lead, Oxidative Stress, and Chelation TherapyConcentration andCompound Duration Species BloodLeadEffectsReference2000 ppm Pb acetate,oralI chelatorsLA, DMSA,MiADMSALA + DMSA + LA+MiADMSA4 wks, 5 days oftreatment withantioxidant orchelatorsMale Wistaralbino ratsNormal: 1.42 μg/dLPb: 40.93 μg/dLPb + chelators: 38.5–4.27 μg/dLTreatment with all the chelators reduced hepatic GSH and reduced GSSGlevels. Significant beneficial role ofAlpha-lipoic acid (LA), in recoveringthe altered biochemical parameters, however showed no chelatingproperties in lessening body Pb burden either from blood, liver, or kidney.Most beneficial effects against Pb poisoning was observed with combinedtreatment of lipoic acid and either DMSA (meso 2,3-dimercaptosuccinicacid) or MiADMSA (Mono isoamyl DMSA).Pande and Flora(2002)0.1% Pb as acetate indrinking waterDMSA—50 mg/kg,i.p./dMiADMSA—50mg/kg, i.p./d3 mo—Vitamin E 5 mg/kgand vitamin C25 mg/kg/d, i.v. andoral5 days post-PbexposureMale Wistar rats—Single or combined administration of vitamin C,α-tocopherol and thechelators DMSA and Mi ADMSA against the Parameters of Pb inducedoxidative stress– thiol chelators and the vitamins could bring the bloodALAD to normal levels, most significantly by combined administration ofMi ADMSA with vitamin C. Vitamin C and E were effective againstreducing oxidized glutathione ( GSSG), and thibarbituric acid reactivesubstance(TBARS) and increasing catalase activity. MiADMSA andDMSA with vitamin C were effectivein increasing hepatic GSH levels.In summary combined treatment regimens with thiol chelators andvitamins seem very effective in reducing the Pb induced oxidative stress.Flora et al. (2003)500 mg/kg Pb acetatedaily, oral treatmentwith chelatorsMultiple durations(2, 4, and 6 wks)Male Albino rats Control: 0.32 μg/dLPb-exposed:0.48–0.56 μg/dLPb + chelators:0.32–0.36 μg/dLImpact of combined administration of vitamin C and Sylimarin on Pbtoxicity. Combined treatment of Pb-exposed animals with vitamin C andSilymarin showed marked improvement of the adverse biochemical,molecular and histopathological signs associated with Pb toxicity.Shalan et al. (2005)Pb as acetate 0.2% indrinking waterLA 25 mg/kg b.wt andDMSA 20 mg/kg b.wt5 wks followed bya 6th wkadministration ofLA and or DMSAMale Albino rats—Pb treatment for 5 wks resulted hepatic enzymes alanine transaminase,aspartate transaminase, and alkaline phosphatase, increased lipidperoxidation, and decreased hepatic anti oxidant enzymes. LA or DMSAalone, partially abrogated these effects, however, in combinationcompletely reversed the lipid oxidative damage.Sivaprasad et al.(2004)Abbreviationsb. wt.—body weightaCYP—Cytochrome P-450SOD—Super oxide dismutaseGSH—GlutathioneGSH/GSSG Ratio—Reduced Glutathione/Oxidized GlutathioneMDA—MalondialdehydeAl—AluminumAs—ArsenicMiDMSA—Mi monoisoamyl DMSACr—CromiumV—VanadiumPb—LeadNAC—N acetyl cysteineFeSO4—Ferrous sulphateAlCl3—Aluminum chlorideVCl3—Vanadium chlorideCdCl2,—Cadmium chlorideCuSO4—Copper sulphateCrCl3—Cromium chlorideMnCl2—Manganese chlorideNiSO4—Nickel sulphateCoCl2—Cobalt chlorideLAN—"Linolenic acidDPPD—DPPD,N-NDiphenyl –p-phynylene-diamineLA—Lipoic acidDMSA—Monoisoamyl DMSA

# AX5-171Table AX5-10.5. Lead-induced Liver Hyperplasia: Mediators and Molecular MechanismsConcentrationDurationSpeciesBlood LeadEffectsaReference—— Rat—Apoptosis plays a major role in the regressive phase of Pb nitrate inducedhepatic hyperplasia as detected bythe apoptotic bodies by in situ endlabeling and HandE sections of the hepatic tissue. HandE scores mostlycells in apoptosis phase II, ISEL (in situ end labeling) scores for cells inphase I. Combination of these twomethods is suggested for the betterunderstanding of the extent and natureof apoptotic process in liver cellstreated with chemicals.Nakajima et al.(1995)A. Pb nitrate,100 μM/kg b.wt,intra-gastricB. Diethylnitrosoamine200 mg/kg b.wt, i.p.3 and 15 days Male WistarAlbino rats—Mitogenic stimuli (3 days Pb nitrate treatment) and complete regression(15 days after the treatment), affected the apoptosis differentially.Influence of apoptosis Vs necrosison the growth of hepatocytes initiatedby diethyl nitrosamine followed by Pbnitrate treatment indicated that theregenerative response elicited by a necrogenic dose of CCL4 promotedGSTP (Placental glutathione), a pre-neoplastic marker positive cells asagainst the Pb nitrate that induced the apoptosis.Columbano et al.(1996)0–100 μM Pbsulphate, Pbmonoxide, Pbchloride and Pbacetate up to 1 mM,culture media.Multiple time pointsranging from 24 hup to 7 daysREL liver cells—Pb compounds showed a doseand time related effect on REL liver cellproliferation with varying potenciesspecific to the different Pb salts.Pb acetate was the most effective andPb monoxide, the least effective.On 1 hr treatment none of the compoundstested affected the intracellularcommunication.Apostoli et al.(2000)Choline 1g/kg/d indrinking water0, 20, and 24 h Male and femalerats , partialhepatectomy—PKC isozymes during liver cell regeneration— PKCδshowed apronounced increase 20h after partial hepatectomy.α,β, and Zeta at 24 hcorresponding with S-phase. Sexualdimorphism matching with sexualdifferences in DNA synthesis was evident. Administration of choline wasable to modulate the protein kinaseC isozyme pattern in females inrelation to DNA synthesis and c-myc expression. Taken together the datapositively implicatesα,β, and Zeta in growth after partial hepatectomyandδin negative regulation.Tessitore et al.(1995)Pb nitrate, 75 μM/kgb.wt, single i.v.6 h–4 wksAdult male Albinorats—Pb induced significant increase in liver weight. Increased 3H Thymidineincorporation. Pb induces extensive hypomethylation in treated rat livers.Site-specific effect on methylation was confirmed at Hpa II, Msp I,Hae III.Kanduc et al. (1991)75 μmol/kg b. wt. Pbnitrate in adult and 20μg/mL in the young,i.v.; single doseAnalyses at 72 h Male WistarAlbino rats—Effect of Pb nitrate on the 5- methyl deoxy cytidine (5-mdcyd) content andthe HpaII, MSPI, Hae III restriction patterns of hepatic DNA from young,middle aged and senescent rats. The results indicated that the methylationpattern of genomic DNA changedsignificantly with age and themethylation patterns were differentially affected in all the threepopulations.Kanduc and Prisco(1992)

# AX5-172Table AX5-10.5 (cont’d). Lead-induced Liver Hyperplasia: Mediators and Molecular MechanismsConcentrationDurationSpeciesBlood LevelEffectsaReference10 μmol/100 g bodyweight Pb nitrate, i.v.Multiple analysesup to 40 hMale Wistar rats,hepatocytesfrom partialhepatectomy andPb nitratetreatment.—The kinetics of DNA synthesis andexpression of Proto oncogenes inpartially hepatectamized liver cellsand Pb nitrate treated hepatic cellsindicated peak DNA synthesis after 24h in the formal and after 36 h in thelater case. Both proliferative stimuli induced c-fos, c-myc and c-Ha Rasexpression. Induced c-myc expression persisted for up to 40h during thePb nitrate- induced liver cell proliferation. Pb induces hepatic hyperplasiathrough changes in proto-oncogene expression.Coni et al. (1989)100 μmol/kg, b. wt.Pb nitrate, i.v.Analyses at multipletime points,0.25–24 hMale WistarAlbino rats—Proliferative stimuli by means of Pbnitrate exposure resulted in increasedexpression of c-jun m-RNA where as compensatory regeneration inpartially hepatectamized cells occurred through increased expression of c-fos and c-jun. Different mitogenicstimuli induced differential expressionof these protooncogenes, in addition had a different profile than cells frompartial hepatectomy despite the cell cycle timings being the same in somecases.Coni et al. (1993)100 μmol/kg b. wt. 8 hMale SpragueDawley rats—In rat liver, in addition to a few hepatocytes four types of non parenchymalcells namely, fibroblasts, macrophages,bile ducts and periductular cellsproliferate in response to Pb nitrate treatment. This growth is not relatedto adaptive response secondary to parenchymal enlargement. However,such growth in parenchymal cellsseems dormant and does not play afunctional role in adultliver epithelial growth.Rijhsinghani et al.(1992)100 μmol/kg b. wt.,i.v.Multiple analysestime points,1–120 hMale Wistar rats—Both mRNA levels and enzyme activity of DNA polymeraseβmarkedlyincreased before and/or during DNA synthesis in proliferating hepatocytesin Pb nitrate treated and partially hepatectomized rats. 5 fold increase inthe enzyme activity was observed 8 h after Pb nitrate administration. Inthe regenerative liver cells a 3 fold increase was observed 24–48h afterpartial hepatectomy.Menegazzi et al.(1992)100 μ mol/kg b. wt.,i.v. Pb nitrateAnalyses at multipletime points, 8 h to15 daysMale Wistar rats—Pb nitrate induced Poly(ADP-ribose) polymerase mRNA 24 hr afterexposure. A 2 fold increase in themRNA levels of the enzyme occurred2 days after the exposure. Such changes were also observed in hepaticcells from livers of partial hepatectomy. These changes preceded theincrease in DNA synthesis and remainedhigh during the time of extensiveDNA synthesis.Menegazzi et al.(1990)

# AX5-173Table AX5-10.5 (cont’d). Lead-induced Liver Hyperplasia: Mediators and Molecular MechanismsConcentrationDurationSpeciesBlood LeadEffectsaReference30 mg/kg b. wt.Pb nitrateMultiple time pointsup to 8 daysAdult male andfemale rats— Pb nitrate induced liver hyperplasia exhibited sexual dimorphism wheremitogenic action was less effectiveand was delayed in females ascompared with males. Pre administration with choline partially filledthese sexual differences.Tessitore et al.(1994)30 mg/kg b. wt.Pb nitrateMultiple time pointup to 60 hAdult male andfemale rats— Pb nitrate induced liver hyperplasia exhibited sexual dimorphism.Pre-administration with choline partially filled these sexual differences.Significant down regulation of PKCβand PKCαactivities occurredduring Pb induced proliferation.Tessitore et al.(1994)100 μmol/kg b. wt.Pb nitrate, i.v., singledose.Multiple time pointanalyses rangingfrom 12–168 hMale Wistar rats Serum Pbconcentrationspeaking to 50–60 μg/dL between12–24 h andremaining up to40 μg/dL up to 108 hEffect of Pb nitrate on protein kinaseC (PKC) activity. A single dose ofPb nitrate resulted in enhanced activityof PKC in the purified particulatefraction of the rat liver, reached itspeak activity by 24 h which lasted for48 h. This was accompanied by increased frequency of mitotic cells.These results indicate, Pb nitrate induced PKC activity may play a role inliver cell proliferation.Liu et al. (1997)A. Mitosis—Pb nitrate100 μM/kg, i.v.Ethylenedibromide100 mg/kg , intragastricCyproteroneacetate, 60 mg/kgintra gastric.B. Hepatocytenodules diethylnitrosamine200 mg/kg30'–3 hAdult male Wistarrats—Liver cell proliferation by enhancedDNA synthesis was observed with themitogens Cyproterone acetate, ethylenedibromide, and Pb nitrate as earlyas 30 mints after treatment and persisted even after 5 days of treatment byPb nitrate administration.hepatocytes isolated from pre neoplastic liver nodules have also exhibitedenhanced cell proliferation.Coni et al. (1992)Pb nitrate, single i.v.100 μm/kg b.wtLPS—12.5 μg/rat,post Pb nitratetreatment.Multiple analyses at3, 6, 12, 24, and36 hMale Wistar rats—Stimulation of hepatocyte cell proliferation by Pb nitrate was notaccompanied by changes in liver levels of Hepatocyte growth factor(HGF), Transforming growth factorα(TGFα), or TGF-β1 m-RNA. Pbnitrate treatment resulted in the enhancement of Tumor necrosis factorαata time preceding the onset of hepatocyte DNA synthesis, indicating its rolein Pb induced hepatic cell proliferation.The survival ofPb nitrate treatedrats decreased significantly with an after treatment of LPS(lipopolysaccharide).Shinozuka et al.(1994)

# AX5-174Table AX5-10.5 (cont’d). Lead-induced Liver Hyperplasia: Mediators and Molecular MechanismsConcentrationDurationSpeciesBlood LeadEffectsaReference15 mg/kg b. wt.Pb acetatePb+ LPS groupanalyzed after 14 hand the rest after24 h after PbadministrationMale SpragueDawley rat—Pb augments the lethality of endotoxin lipopolysaccharide (LPS) in ratsand enhances liver injury, which is further enhanced by TNF. Pb + LPStreatment increased both serum TNF concentrations and TNF area ascompared to LPS alone. simultaneousadministration of Pb with eitherLPS or TNF, serum aspartate transaminase, alanine transaminase, alkalinephosphatase, glutamyl trans peptidase and plasma triglyceride levels weremarkedly increased.Honchel et al.(1991)Pb nitrate 100 μM/kgb. wt. i.v. single doseMultiple time pointsof analysesextending up to 48 hafter treatmentMale Wistar rats—Pb nitrate and ethylene bromide induce liver cell proliferation viainduction of TNFα. Dexa methasone, a known TNF inhibitor, decreasesTNF expression and liver cell proliferation by these mitogens. Thesestudies support the fact that TNF might mediate hepatic cell proliferationby Pb nitrate and ethylene bromide.Ledda-Columbanoet al. (1994)100 μmol/kg b. wtPb nitrate, single, i.v.Multiple time pointsof analyses up to48 h—Pb nitrate (LN) treatment resulted in increased Brdu incorporation ofhepatocytes and non parenchymal cellsat 12 h after treatment and reachedthe peak index at 36 h. Rats given a single i.v. of recombinant TNFαenhanced proliferation in non parenchymal cells after 24 h, the labeling ofhepatocytes at 36 h. NAF, Nafenopin another mitogen which does notinduce liver TNFα, increased the number of labeled hepatocytes withoutincreasing the labeling of non parenchymal cells indicating that only Pbnitrate induced proliferation is mediated by TNFαand these mitogensinitiate proliferation in different cellsbased on their capacity to stimulateTNFαproduction.Shinozuka et al.(1996)100 μmol/kg b. wt.single i.v.Multiple time pointsof analyses up to80 hMale SpragueDawley rats—Pb nitrate induces liver cell proliferation in rats without accompanyingliver cell necrosis. This proliferation involves enhanced TNF mRNA andlevels but not hepatocyte growth factor. The role ofTNF in Pb nitrateinduced liver cell proliferation is supported by the inhibition of TNF andreduced hepatocyte proliferation by several TNF inhibitors.Kubo et al. (1996)100 μmol/kg b. wt.i.v. single doseMultiple time pointsof analyses up to24 hMale Wistar rats—Pb nitrate inducedliver cell proliferation involves TNFαproduction,enhanced NF-κB activation increased hepatic levels of iNos mRNA asopposed to other mitogens such as Cyproterone acetate or Nafenopine.Menegazzi et al.(1997)100 μmol/kg b. wt.i.v., single doseMultiple time pointanalyses up to 96 hMale SpragueDawley rats—The role of neurotrophins, the nerve growth factor (NGF), the brainderived neurotrophic factor (BDNF)and neurotrophin-3 (NT-3) in Pbnitrate treated liver cells was studied.LN, treatment resulted in increasedin the levels of NGF, BDNF andNT-3. The increase in neurotrophinreceptors and the gene expression werecorrelate with liver weights. Thisstudy demonstrates that Pb nitrateinduced hyperplasia may be mediatedby neurotrophins.Nemoto et al.(2000 )

# AX5-175Table AX5-10.5 (cont’d). Lead-induced Liver Hyperplasia: Mediators and Molecular MechanismsConcentrationDurationSpeciesBlood LeadEffectsaReferenceMultiple doses0–50 μM, culturemediumMultiple time pointsup to 24 hHepatocytes fromAdult male Swiss-mice, primary—Interaction between Pb and cytokines in hepatotoxicity– Pb potentiatedcytokine-induced oxidative stress by decreasing GSH and increased effluxof Oxidized glutathione (GSSG). Combined treatment resulted in adecline in intra cellularATP concentration.Sieg and Billing(1997)50 μM Pb acetate,culture medium24 h Rat hepatocyteand Kupffer celland granulocyteco-cultures—Pb stimulates intercellular signaling between Kupffer cells andhepatocytes which increased synergistically at low lipopolysaccharidelevels. These signals promote proteolytic hepatocyte killing incombination with a direct cellular interaction between the granulocytesand hepatocytes.Milosevic andMaier (2000)10 μM/110 g b. wt.,single i.v.Multiple time pointanalyses up to5 daysAdult male Wistarrats—Pb nitrate induced hepatocyte apoptosis was prevented by pre-treatmentwith gadolinium chloride, a Kupffercell toxicant—Role for Kuffer cell inhepatocyte apoptosis.Pagliara et al.(2003a)10 μmol/100 g b. wt.single i.v.Multiple time pointsup to 9 daysMale Wistar rats—Pb nitrate-induced liver hyperplasia in rats results in a significant increasein the expression of aceyl glycoprotein receptor (ASGP-R) during theinvolutive phase of Pb nitrate induced hyperplasia in rat-liver, whichcoincided with the massive death by apoptosis of the same cells.A significant rise in the galactose-specific receptors was also observed3 days after the treatment. These studies demonstrate that carbohydratereceptors regulate Pb nitrate induced liver cell apoptosis.Dini et al. (1993)10 mmol/100 g,Pb nitrate, i.v.Multiple time points Male Wistar rats—Demonstration of the expression of carbohydrate receptors on Kupffercells. Pb nitrate induced apoptosis inKupffer cells and internalization ofapoptotic cells (Phagocytes) is mediated by both Mannose and Galactosereceptors.Ruzittu et al. (1999)

# AX5-176Table AX5-10.5 (cont’d). Lead-induced Liver Hyperplasia: Mediators and Molecular MechanismsConcentrationDurationSpeciesBlood LeadEffectsaReferencePb (No3)2, , i.v.100 μM/110 g .b. wt1, 3, and 5 days In vivo Adultmale Wistar rats—GdCl30.75 mg/100 g. b. wt,i.v.2, 4, or 24 h before Pbnitrate injection.—In vitro, 10 mM PbnitrateAnalyses at multipletime points up to 24 hin Hep G2 cells and at24 and 48 h inKupffer cellsHep G2 cells—Hepatic apoptosis induced by Pb nitrate in vivo is abolished by gadoliumchloride, a Kupffer cell toxicant thatsuppresses Kupffer cell activity andreduces to half the apoptotic rate. Pbnitrate treatment also deprives thehepatic cells from reduced glutathione and this process is reversed byGadolium chloride. Pb nitrate induces apoptosis in Kupffer cells, andHepG2 cells in vitro.Pagliara (2003b)Multipleconcentrationsvarying from300 nM–10 μM,up to 100 μM incertain in vitro expts1, 2, 4 and 6 days Hepatoma cellline, H4-II-C3—Acute effect of Pb on glucocorticoid regulation of Tyrosineaminotransferase (TAT) in hepatoma cells. Pb treatment does notsignificantly alter initial glucocorticoidreceptor number or ligand binding.Pb may perturb PKC mediated phosphorylations in the glucocorticoid-TAT signal transduction system. Pbalso may be increasing the turnoverof TAT by actions at transcription, translation and /or post translation.Heiman and Toner(1995)0–10 μM Pb acetatein the culture medium24 and 48 hH4-IIE—C3hepatoma cellculture model—In HTC cells glucocarticoid signal transduction pathways involve calcium-mediated events and PKC isoforms, Pbexposure interferes with calciummediated events and aberrant modulation of PKC activities and maycontribute to the over all toxicity of Pb.Tonner and Heiman,(1997)aCYP—Cytochrome P-450b. wt.—body weight

# AX5-177Table AX5-10.6. Effect of Lead Exposure on Liver Heme SynthesisConcentrationDurationSpeciesBlood LeadEffectsaReference75 mg Pb/kg b. wt.,i.p.Multiple time pointanalyses 0–30 hC57 BL/6 mice — Pb poisoning decreases P-450 as a consequence of two differentmechanisms, a mechanism unrelated to heme where P-450 transcription isinhibited (reduces the synthesis and activity), and a second mechanismwhere by inhibition of heme synthesis occurs decreasing the hemesaturation of P450 and/orapo-P450 content.Jover et al. (1996)10−5ppm Pb nitrate Multiple analyses upto 24 hRLC-GA1 Ratliver cell line—Pb increases heme synthesis in RLC-GA1 in rat livercell line, whenmeasured by the amount of59Fe incorporated into heme fraction.Increased incorporation of59Fe into the heme fraction of the Pb treatedcells was the result of increased uptake of iron59Fe into the heme fractionof Pb treated cells.Cellular degradation of Pb was notsignificantly affected by Pb.Lake andGerschenson (1978)A. Triethyl Pb-3.5and 8.0 mg/kgb.wt.Pb nitrate3.5, 25, and100 mg/kgSingleSubcutaneousMultiple analyses upto 28 daysControl: 5.2 μg/dLTriethyl Pb 8.0 mg/kgb.wt.:19.6 μg/dLPb nitrate25 mg/kg b.wt.:19.6 μg/dLPb nitrate100 mg/kg b.wt.:27.2 μg/dLB. In vitro,10−3–10−9Mtriethyl Pb or Pbnitrate30 minAdult maleFischer rats—Triethyl Pb chloride has a similarpotency to inorganic Pb nitrate ininhibiting ALAD both in vitro and invivo. Liver and blood ALAD havesimilar sensitivities to Pb compounds.Inhibition is reduced in thepresence of Zn.Bondy (1986)5 μM Pb acetate orPb diethyldithio-carbomate Pb uptakestudies 0.33–10 μMMultiple analysesfrom0–20 hRat primaryhepatocytecultures—Effect of Pb and diethyl dithiocarbomates on rat primary hepatocytes asstudied with Pb acetate and or Pb-diethyldithiocarbomate complex (PbDTC2l) labeled with203Pb indicated that (Pb DTC2l) complex caused amore rapid and stronger inhibition of ALAD activity than Pb acetate.Uptake of Pb was rapid and higher with the complex than Pb acetate.The complex also inhibited the ALADactivity in vitro when incubatedwith purified ALAD enzyme.Oskarsson andHellström-Lindahlet al. (1989)Per OS eqimolardoses (17 μM Me/kg)of SnCl2or Pb(CH3COO)2every day5 daysFemale rabbits Control:3.48 μg/100 cm3Pb: 17.50 μg/100 cm3Pb decreased liver and bone marrowALAD, but had no change in theAminolevulinic acid synthetase (ALA-S) and increased erythrocyte freeprotoporphyrin.Zareba andChmielnicka (1992)

# AX5-178Table AX5-10.6 (cont’d). Effect of Lead Exposure on Liver Heme SynthesisConcentrationDurationSpeciesBlood LeadEffectsaReferencePb 500 ppm indrinking water14 days Male ddY mice — Urinary excretion ofβ-Aminoisobutyric acid (ABA) andδ-aminolevulinicacid (ALA) increased significantly inmice exposed to Pb in drinkingwater for 14 days. The degree of increasing excretion for ALA was higherthan urinary ABA. Liver and kidney ALA dehydratase was inhibited,while ALA synthatase was not affected.Tomokuni et al.(1991)0.5 or 2.4 μM Pbacetate in culturemediumAnalyses at multipletime points,0–28 daysHepatocytecultures on 3T3cells—Hepatocyte cultures on 3T3 cells produce and excrete porphyrins for28 days. Pb exposure for 4 wks alters cell morphology and producescytotoxic effects that could be monitored by altered porphyrin excretion.Quintanilla-Vegaet al. (1995)500 ppm Pb indrinking waterRat exposure 62 daysHuman occupationalexposure0.3–38 yrs.A. Male WistarratsB. Pb smeltworkers, males—Pb exposure significantly increases the urinary ALA (Aminolevulinicacid) and Coproporphyrins (CP-III>CP-I in rats and exposed workers.Urinary 5-hydroxy indole acetic acid was notinfluenced by Pb exposure.Ichiba andTomokuni (1987)A. Cu deficient diet:1 mg/kg Cu inthe dietB. Moderatelydeficient:2 mg/kgC. High Zn diet:60 mg/kg b. wt.4 wksWeanlingSprague Dawleyrats—High Zn in the diet reduces plasma copper, but not plasma ceruloplasminactivity or the recovery of plasmacopper or ceruloplasmin activity afteroral copper sulphate of Cu-deficientrats. High dietary Zn also modifiesthe response of plasma SOD activity to dietary copper , but does notinfluence RBC SOD activity.Panemangalore andBebe (1996)1200 mg/kg b. wt. Pbacetate in diet, Subacute toxic studies400 mg/Pb4 wksBroiler chickens—Liver porphyrin levelsincreased during Pb toxicosis. Concurrentadministration of selenium or monensin in the feed further enhances thisprocess.Khan and Szarek(1994)0–100 μM Pb acetatein the culture medium19 hPrimary Rat andchick embryohepatocytecultures—Formation of Zn protoporphyrins in cultured hepatocytes. Pb did notspecifically increase Zinc protoporphyrin accumulation or alter ironavailability in cultured hepatocytes.Jacobs et al. (1998)

# AX5-179Table AX5-10.6 (cont’d). Effect of Lead Exposure on Liver Heme SynthesisConcentrationDurationSpeciesBlood LeadEffectsaReferencePb acetate, 160 mg/L,semi liquid diet, oral8 wks Male Wistar rats — Rats exposed to Pb had a higher blood and liver Pb, increased erythrocyticprotoporphyrin. Pb exposure also resulted in hypoactivity ofaminolevulinate dehydrase.Rats exposed to ethanol and Pb had altered abnormalities in heme similarto animals exposed to Pb alone.Hepatic levels of Zn decreased significantly only in animals exposed toboth.Hepatic GSH, urinary ALA and porphyrin levels were maintainedsimilarly in all the groups.Transferrin bound iron uptake by Pb wasalso inhibited by Pb at higherconcentrations such as 4 μM.Santos et al. (1999)Pb acetate,0.0625 μM–32 μM,in vitro10 min pre incubationand 20 minuteincubationRabbitreticulocytes—The effect of Pb on ferrous iron transport is similar between Pb chloride,acetate, and nitrate and reversible.Uptake of ferrous iron into all (heme,cytosolic and stromal fractions) wasinhibited by low concentrations of Pb.50% inhibition in the uptake by cytosol occurred at 1 μM Pb.Qian and Morgan(1990)A. Transgenicmice carryingchimerichuman TFgene—These studies present evidence for the modulation of the synthesis ofhuman transferrin by Pb. In transgenic mouse with chimeric humanchloromphenical acetyl transferase Pb regulates human Transferrin (TF)transgenes at the m RNA level. Liver catalase (CAT) enzyme activity,CAT protein, and TF-CAT m-RNA levelswere all suppressed. Pb did notalter other liver proteins,mouse TF and Albumin.1, 5, or 10 mg/kgb. wt. Pb acetate ornitrate, i.p.10−4M Pb acetate forHep G2 cells3 daysB. Hep G2 cells—Pb suppressed synthesis of Transferrin protein in cultured humanhepatoma Hep G2cells.Adrian et al. (1993)10 mg Pb/kg b. wt. asPb acetate , i.p., singleinjection10 and 100 μM PbacetateAnalyses at multipletime points up to 72 hTransgenic miceand Hep G 2cells—Pb suppresses human transferrin synthesis by a mechanism different fromacute phase response. Common proteins such as C3 and albuminassociated with acute phase response were not altered by Pb. Pb acetatesuppresses35S-transferrin protein synthesis and m-RNA levels in Hep G2cells and transgenic mice, while LPS altered only protein levels.Barnum-Huckinset al. (1997)aCYP—Cytochrome P-450b. wt = body weight

# AX5-180Table AX5-10.7. Lead and In Vitro Cytotoxicity in Intestinal CellsCompound andConcentrationDuration Species BloodLeadEffectsaReferenceHgCl2, CdCl2, Ti2SO4, Pb(NO3)2–concentration notgiven clearly,Butathionine, up to1 mMGlutathione 1 mMN-Acetyl cysteine,1 mMCell proliferationassays 48 hGlutathione depletionassays 48 hSulphahydrylrepletion studies.I-407, Intestinalepithelial cellline.—Rank order cytotoxicity of various metal salts in I-407 intestinal epithelialcells in terms of LC50values—HgCl2(32 μM) > CdCl2(53 μM), CuCl2(156 μM) > Ti2SO4(377 μM) > Pb (NO3)2(1.99 mM)Role of Glutathione, in the cytotoxicity of these metals by the assessmentof GSH depletion by Butathioninesulfoxamine pretreatment at noncytotoxic concentration increased the toxicity of HgCl2(5.7-fold), andCuCl2(1.44-fold).Administration of glutathione, with either HgCl2or CdCl2did not protectthe cells against the toxicity.N-acetyl cysteine reduced the cytotoxicity of mercury.Keogh et al. (1994)aCYP—Cytochrome P-450

# AX5-181Table AX5-10.8. Lead and Intestinal Uptake—Effect on Ultrastructure, Motility, Transport, and MiscellaneousCompound andConcentrationDuration Species BloodLeadEffectsaAuthorsPb acetate, 0.1%, indrinking waterMultiple analyses at2, 30, and 60 daysafter Pb exposureMale Wistar rats — Small intestinal gobletcells are involved in Pb detoxification.Pb treatment for 30 days produces characteristic goblet cells in theintestine and Pb appears in conjunction with goblet cell membrane.Prolonged exposure to Pb more than30 days caused silver sulphidedeposition (indicative of heavy metal deposition) in the mucus dropletsof cytoplasmic goblet cells.Tomczok et al.(1988)100 mg/Pb acetate/kgb. wt.Multiple analyses at2, 30 and 60 daysMale Wistar rats — Pb poisoning changes the ultra structure of intestine.30 days Pb exposed rat intestinal enterocytes showed numerous, smallrough-membraned vesicles and prominent, dilated golgi complexes, intheir cytoplasm.By 60thday, Pb-exposed rats had a vacuolated cytoplasm and prominentgolgi filled with vacuoles.Tomczok et al.(1991)Added Pb concentrationin the milk—0–80 μg/mL—Adult and Infantrats (16 days)Fresh or frozen rator Avian milk— 90% of Pb in rat and bovine milkwas found associated with caseinemicelles regardless of whether the milkis labeled in vitro or in vivo with203Pb. Similarly Pb in infant milk formula was also predominantlyassociated with casein, however, toa much lower extent than rat andbovine milk formulae.Pb tracer studies indicated that in infant rats, as the milk traversed throughthe intestine, in the collected luminal fluid, Pb was primarily associatedwith casein curd and remained as a nonprecipitable, nondialyzable fractionas it moved to the small intestine, indicating that Pb remains with proteinfraction as it traverses through the stomach and small intestine fraction.Beach and Henning(1988)Pb as Pb acetate, for 0.5–10.0 μM, Zn as Znacetate 0, 5, 10, or 50 μMTemperature variationExpts, 5 μM Pb, andincubated for 10 min at 4,22, or 37°C5, 10, 30 or 60 min,Simultaneously withPb for 10 minIncubation time10 minIEC-6 normal ratintestinalepithelial cells— Pb uptake by IEC-6 cells depends on the extracellular Pb concentration.Pb transport in IEC-6 cells is timeand temperaturedependent, involvessulphahydryl groups, and is decreased by the presence of Zn.Dekaney et al.(1997)

# AX5-182Table AX5-10.8 (cont’d). Lead and Intestinal Uptake—Effecton Ultrastructure, Motility, Transport, and MiscellaneousCompound andConcentrationDuration Species BloodLeadEffectsaAuthorsOECD(Organisation forEconomic Co-operationand Development)medium was artificiallycontaminated at 1, 3, 5, or10 times the Dutchintervention value of530 mg/Pb/kg dry wt. Pbcontaining medium waspresented at the apicalsurface of the cells in 2mL DMEM/chyme.Neutral red uptakestudies hadDMEM/chime with low5 μM and high 50 μM PbcontentCell viabilitystudies—24 hincubation.Pb transport studies,1, 3, 5, and 24 h— Transport of bioaccessible Pb across the intestinal epithelium—In Coco-2cells exposed to artificial chime, within 24 hrs. App. 27% of the Pb wasassociated with the cells and 3%were transported across the cellmonolayer. Pb associated with cells showed a linear relationship with thePb available in the system.Results indicate that only a fraction ofthe bioavailable Pb is transportedacross the intestinal epithelium.On the basis of Pb speciation in chime, It could be attributed thatdissociation of labile Pb species, such as Pb phosphate, and Pb bilecomplexes and subsequent transport of the released free metal ions flowtoward the intestinal membrane.Oomen et al. (2003)44 mg/kg/d Pb as53 mmol/L Pb acetate4 wks Rat — Pb exposure significantly decreases the amplitude of contraction in ratduodenum.Karmakar andAnand (1989)2.5 mg/mL Pb acetate indrinking water55 daysColonic segmentstaken fromchronicallyexposed guineapigsExposed:80 μg/dLColonic propulsive activity as measured by the velocity of thedisplacement of the balloon, from theoral to the aboral end, did not getaffected significantly by Pb treatment.In longitudinal muscle-myentericplexus preparations of distal ileum, addition of Pb nitrate (100 μm) causedslight increase in cholinergic contractions.100 μM Pb nitrate,in vitroDuration notspecifiedMuscle–myentericplexuspreparations ofdistal ileum ofcontrolled animals— Moderate decrease of electrically induced cholinergic contractions.Rizzi et al. (1989)

# AX5-183Table AX5-10.8 (cont’d). Lead and Intestinal Uptake—Effecton Ultrastructure, Motility, Transport, and MiscellaneousCompound andConcentrationDurationSpecies Blood LeadEffectsaAuthors40 μM–240 μM Tri ethylPb added in a cumulativemanner in vitro to mid-ileal portion.7.5 sec–2 min Swiss mice JVI1ileum— 1. Peristaltic contractile activity ofileum as measured as a change inperiod duration and force amplitude indicated that tri ethyl Pb (TEL)concentrations of <40 μM had no obvious effects on these parameters.2. In the concentration range between 40 μM–120 μM, tri ethyl Pbaffected the rhythm of contractionin a concentration dependent mannerwith elongation in period andreduction in force amplitude.3. At concentrations above 120 μM, TEL induced irreversible dramaticchanges in the ileal contractile activity.Shraideh (1999)aCYP—Cytochrome P-450

# AX5-184Table AX5-10.9. Lead, Calcium, and VitaminD Interactions, and Intestinal EnzymesCompound andConcentrationDuration Species BloodLeadEffectsaAuthorsCa—0.5% in diet(low calcium)1.2% in diet(high calcium)Pb—0.8% in the dietas Pb chloride10 days White LeghornCockerels— Dietary Pb affects intestinal Caabsorption in two different waysdepending on the dietary Ca status.A. In chicks fed low Ca diet (0.05%), ingested Pb inhibited intestinal47Ca absorption, intestinal Calbindin D, and alkaline phosphatasesynthesis in a dose dependent fashion.B. In normal calcium diets (1.2%) Pb exposure had no bearing on theintestinal Ca absorption, or Calbindin D, or Alkaline phosphatasesynthesis and in fact elevated theirlevels at higher Pb concentrations.These results indicate that the primary effects of Pb in both cases,occur at or prior to intestinal protein synthesis involvingCholecalciferol endocrine system.Fullmer and Rosen(1990)Ca—0.1% or 1.2% in thediet with Pb—0.1–0.8%as Pb chloride in the diet1 or 2 wksLeghornCockerels— —Dietary Ca deficiency, initially(1st week) stimulates Ca absorptionand Calbindin D levels regardless ofdietary Pb intake.—At 2 wks, this response is reversed by Pb.—Intestinal Pb absorption was enhanced by Ca deficiency initially andwas inhibited by prolonged dietary Pb intake.—Intestinal Pb absorption was increased in adequate Ca situation, butonly after 2 wks at the lower levels of dietary Pb.Fullmer (1991)Ca—0.1–1.2%Pb—0.8%2 wksWhite LeghornCockerels— Interactions between dietary Pb and Ca-influence on serum vitamin Dlevels.—Pb ingestion and Ca deficiency alone or in combination generallyincreased serum 1,25 (OH)2 D levels over the most of the range ofdietary Pb and Ca.—In severe Ca deficiency, Pb ingestion resulted in significant decreases inhormone concentration.—Similarities in response profiles for 1,25 ( OH)2 D, intestinal Caabsorption and Calbindin- D suggestedmajor interactions between Pband calcium mediated changes via circulating1,25(OH)2 Dconcentration.Fullmer (1997)

# AX5-185Table AX5-10.9 (cont’d). Lead, Calcium, and Vitamin D Interactions, and Intestinal EnzymesCompound andConcentrationDurationSpecies Blood LeadEffectsaAuthorsPb, Alkaline phosphataseand Ca2+ATPase2.0–10.0 mMPb, Sucrase0.5 mM–6.0 mMPb,(-glutamyltranspeptidase1.0–10 mMPb, Acetyl cholineesterase 10.00–35.00 mMIncubation time notspecifiedMale Albino rats Pb inhibited the activity ofseveral intestinal brush border enzymes such asCa2+- ATPase, Sucrase,(-glutamyl-transpeptidase and acetyl cholineesterase with the exception of alkaline phosphatase. Inhibition of Ca2+-ATPase was competitive and that of the other enzymes is by non-competitive means.Gupta et al. (1994)Oral Pb in Similac orapple juice adjusted forattainment of blood Pblevels 35–40 μg/dL.Succimer 30 mg/kg/d204Pb 24.5 nM followedby206Pb 352 nM,Single doseAdministered from8th day post partum,until age 26 wksTwo successive19 days at age 53 wksand 65 wksAdministeredimmediately beforechelationFemale infantRhesus MonkeysPb-exposed:35–40 μg/dLEffect of oral succimer chelation onthe Gastro intestinal absorption andthe whole body retention of PbRadio isotope Pb tracer techniqueSuccimer significantly reduced Gastrointestinal absorption of Pb andincreased urinary excretion of PbThe initial decrease in whole body Pb by 10% was over come whenmajority of administered tracer wasretained in the body after 5 days oftreatment.Cremin et al. (2001)aCYP—Cytochrome P-450

# AX5-186 

# ANNEX TABLES AX5-11

# AX5-187Table AX5-11.1. Lead-binding ProteinsSource OrganSpeciesMolecularWeightProtein Properties Inducible Separation TechniqueGoyer (1968)Kidney RatIntranuclear Pb inclusionbodiesYesGoyer et al. (1970a,b) Kidney RatPb is concentrated in theintranuclear inclusion bodyYesChoie and Richter (1972) Kidney Rat Initial inclusion bodies incytoplasmYesMoore et al. (1973) Kidney RatProtein in inclusion bodies isacidic, with high levels ofaspartic a, glutamic a, glycineand cystineYesMoore and Goyer (1974) Kidney Rat Inclusion bodyprotein is27.5 kDaYes Acrylamide gel electrophoresisShelton and Egle (1982) Kidney Rat Inclusion body is32 kDa with pIof 6.3Named p32/6.3 Yes Two-dimensional gel electrophoresisEgle and Shelton (1986) Brain Rat, mouse,dog, guineapig, andchickenp32/6.3 found NoOskarsson et al. (1982) Kidneycytosol andbrainRat 11.5 and 63 kDa No203Pb binding followed by SephadexG-75 or G-200 chromatography, thenSDS-PAGEMistry et al. (1985) KidneycytosolRat 11.5 kDa, 63 kDa,> 200 kDaRespective Kd values: 13,40, 123 nMNo203Pb binding followed by Sepharose-6B column chromatographyFowler and DuVal (1991) KidneycytosolRat Cleavage product of alpha-2microglobulinNo Chromatography followed by reversephase HPLC, then production ofantibodies Kd 10–8 M

# AX5-188Table AX5-11.1 (cont’d). Lead-binding ProteinsSource OrganSpeciesMolecularWeightProtein Properties Inducible Separation TechniqueSmith et al. (1998) Kidney cortex Human 9 kDa and 5 kDa ACBP and thymosin B4 No Sephadex G-75 fractions <30 kDa,Sephadex A-25, then HPLCGoering et al. (1986)Brain Rat12 kDaNo Labeled (203Pb) cytosol applied toSephadex G-75DuVal and Fowler (1989) Brain Rat23 kDa Glutamic a,aspartic a,cysteine. Not MTNo Labeled cytosol applied to Sephadex G-75, DEAE, followed by SDS-PAGEFowler et al. (1993) Kidney andbrainMonkey Brain Pb-bindingprotein larger thankidneyaspartic a, glutamic a,glycine, serineNo Sephadex G-75 and DEAEQuintanilla-Vega et al.(1995)Brain Human 5 kDa and 20 kDa Thymosin B4 andunidentified proteinNo Sephadex G-75, A-25 DEAE, reversedphase HPLCRaghavan and Gonick(1977)RBC Human Pb-workers10 kDa Yes210Pb binding, Sephadex G-75,followed by SDS-PAGERaghavan et al. (1980) RBC Human Pb-workers10 kDa Pb-binding protein absent incontrols, low in symptomatic,high in asymptomaticYes210Pb binding, Sephadex G-75Raghavan et al. (1981) RBC Human Pbworkers10 kDa Pb in membrane fractioncorrelates inversely with Na-K-ATPaseYes210Pb binding, Sephadex G-75Gonick et al. (1985) RBC Human Pbworkers12 kDa, pI 5.3,and 30 kDaGlycine, histidine, aspartic a,leucineYes Sephadex G-75,HPLC, isoelectricfocusing, SDS-PAGEOng and Lee (1980) RBC Normal human67 kDa Thought to be hemoglobin Yes203Pb binding, Sephadex G-75Lolin and O'Gorman(1988)RBC Human PbworkersLow molecularweightPb-binding protein correlateswith restored ALADYes Sephadex G-75, Pb measured by atomicabsorption

# AX5-189Table AX5-11.1 (cont’d). Lead-binding ProteinsSource OrganSpeciesMolecularWeightProtein Properties Inducible Separation TechniqueChurch et al. (1993a)RBC Human Pbworkers, oneasymptomaticand onesymptomatic6–7 kDaFirst pt had 67% of RBC Pbbound to protein. Second pthad 22% of RBC Pb inproteinYes RBC hemolysate filtered throughAmicon YM 30 membrane. Superose12 column. Pb quantitated by A.A.Church et al. (1993b)RBC Human Pbworkers5, 7 and 12 kDa,pI 4.7–4.930 % cysteine Thought to beMT on basis of greater UVabs at 254 nm than 280 nmYes Superose 12, Amicon YM 30, AmiconYM 2, HPLCXie et al. (1998) RBC Human Pbworkers240 ~ 260 kDa,<30 kDaHigh M.Wt. peak identifiedas ALAD. Low M.Wt. peakseen after adding Pb in vitroYes Bio-gel A column. Pb determined byA.A.Goering and Fowler,(1987a)Kidney RatPre-treatment with zincbefore injecting203Pb leads tozinc-thionein binding PbNo203Pb binding, Sephadex G-75Goering and Fowler,(1987b)Kidney andliverRatPre-Rx with Zn or Cd inducesZn or Zn, Cd-MT. The MTdecreases Pb inhibition ofALADNo203Pb binding, Sephadex G-75Qu et al. (2002);Waalkes et al. (2004)Kidney MT-nullphenotypicmicePb-exposed MT-nulldeveloped no Pb inclusionbodies, accumulated lessrenal Pb than WT

# AX5-190 

# REFERENCES

Abdollahi, M.; Dehpour, A. R.; Fooladgar, M. (1997) Alteration of rat submandibulary gland secretion of protein,

calcium and N -acetyl- β

- D 

# -glucosaminidase activity by lead. Gen. Pharmacol. 29: 675-680.
Aboul-Ela, E. I. (2002) The protective effect of calcium against genotoxicity of lead acetat e administration on bone
marrow and spermatocyte cells of mice in vivo . Mutat. Res. 516: 1-9. Acharya, S.; Acharya, U. R. (1997) In vivo lipid peroxidation responses of tissues in lead-treated Swiss mice. Ind.

Health 35: 542-544.
Acharya, U. R.; Acharya, S.; Mishra, M. (2003) Lead acetate induced cytotoxic ity in male germinal cells of Swiss

mice. Ind. Health 41: 291-294.
Ades, A. E.; Kazantzis, G. (1988) Lung cancer in a non-ferrous smelter: th e role of cadmium. Br. J. Ind. Med.

45: 435-442.
Adhikari, N.; Sinha, N.; Saxena, D. K. (2000) Effect of lead on Sertoli-germ cell coculture of rat. Toxicol. Lett.

116: 45-49. Adhikari, N.; Sinha, N.; Narayan, R.; Saxena, D. K. (2001) Lead-induced cell death in testes of young rats. J. Appl.

Toxicol. 21: 275-277.

Adrian, G. S.; Rivera, E. V.; Adrian, E. K.; Lu, Y.; Buch anan, J.; Herbert, D. C.; W eaker, F. J.; Walter, C. A.; Bowman, B. H. (1993) Lead suppresses chimeric human transferrin gene expression in transgenic mouse
liver. Neurotoxicology 14: 273-282.
Alber, S. A.; Strupp, B. J. (1996) An in-depth analysis of lead effects in a delayed spatial alternation task: assessment of mnemonic effects, side bias, and proactive interference. Neurotoxicol. Teratol. 18: 3-15.
Alexaki, E.; Samara, C.; Alexopoulos, C.; Tsafaris, F.; Smokovitis , A. (1990) Detection of lead in blood, seminal
plasma, and spermatozoa of bulls. Effect in vitro of lead acetate on sperm motility. Bull. Environ. Contam.

Toxicol. 45: 824-828.

Al-Hakkak, Z. S.; Zahid, Z. R.; Ibrahi m, D. K.; Al-Jumaily, I. S.; Bazzaz, A. A. (1988) Effects of ingestion of lead
monoxide alloy on male mouse reproduction. Arch. Toxicol. 62: 97-100.

Alkondon, M.; Costa, A. C. S.; Radhakrishnan, V.; Aronstam, R. S.; Albuquerque, E. X. (1990) Selective blockade

of NMDA-activated channel currents may be implicated in learning de ficits caused by lead. FEBS Lett.

261: 124-130. Alomran, A. H.; Shleamoon, M. N. (1988) The influence of chronic lead exposure on lymphocyte proliferative
response and immunoglobulin levels in storage battery workers. J. BioI. Sci. Res. 19: 575-585.
Altmann, L.; Weinsberg, F.; Sveinsson, K.; Lilienthal, H. ; Wiegand, H.; Winneke, G. (1993) Impairment of longterm potentiation and learning following chronic lead exposure. Toxicol. Lett. 66: 105-112.
Alvarez, J.; García-Sancho, J.; Herreros, B. (1986) Inhibition of Ca2+-dependent K+ channels by lead in one-step inside-out vesicles from human red cell membranes. Biochim. Biophys. Acta 857: 291-294.

Amoruso, M. A.; Witz, G.; Goldstein, B. D. (1987) Alteration of erythrocyte membrane fluidity by heavy metal

cations. Toxicol. Ind. Health 3: 135-144. Angell, N. F.; Weiss, B. (1982) Operant behavior of rats exposed to lead before or after weaning. Toxicol. Appl.

Pharmacol. 63: 62-71.
Angle, C. R.; Thomas, D. J.; Swanson, S. A. (1990) Lead inhibits the basal and stimulated responses of a rat

osteoblast-like cell line ROS 17/2.8 to 1 α , 25-dihydroxyvitamin D3 and IGF-I. Toxicol Appl. Pharmacol.

103: 281-287. Angle, C. R.; Thomas, D. J.; Swanson, S. A. (1993) Osteotoxicity of cadmium and lead in HOS TE 85 and ROS 17/2.8 cells: relation to metallothionein induction and mitochondrial binding. BioMetals 6: 179-184.
Antonowicz, J.; Andrzejak, R.; Smolik, R. (1990) Influence of heavy metal mixtures on erythrocyte metabolism. Int.
Arch. Occup. Environ. Health 62: 195-198. Anttila, A.; Heikkilä, P.; Pukkala, E.; Nykyri, E.; Kauppinen, T.; Hernberg, S; Hemminki, K. (1995) Excess lung
cancer among workers exposed to lead. Scand. J. Work Environ. Health. 21: 460-469.
Anttila, A.; Heikkilä, P.; Nykyri, E.; Kauppinen, T.; Pukkala, E.; Hernberg, S.; Hemminki, K. (1996) Risk of nervous system cancer among workers exposed to lead. J. Occup. Environ. Med. 38: 131-136.
Anwar, W. A.; Kamal, A. A. M. (1988) Cytogenetic effect s in a group of traffic policemen in Cairo. Mutat Res.

208: 225-231. Apostoli, P.; Romeo, L.; De Matteis, M. C.; Menegazzi, M.; Faggionato, G.; Vettore, L. ( 1988) Effects of lead on
red blood cell membrane proteins. Int. Arch. Occup. Environ. Health 61: 71-75.

# AX5-191 Apostoli, P.; Huard, C.; Chaumontet, C.; Martel, P.; Allesio, L.; Mazzoleni, G. (2000) Eff ects of four inorganic lead
compounds on the proliferation and junctional coupling of cultured REL liver cells. Am. J. Ind. Med.

38: 340-348. Appleton, J. (1991) The effect of l ead acetate on dentine formation in the rat. Arch. Oral Biol. 36: 377-382.
Appleton, J. (1992) Dentinogenesis and the calciotraumatic response to the injection of lead or fluoride ions. Scanning Microsc. 6: 1073-1081.
Areola, O. O.; Jadhav, A. L. (2001) Low-level lead exposure modulates effects of quinpirole and eticlopride on
response rates in a fixed-interval schedule. Pharmacol. Biochem. Behav. 69: 151-156. , M. E.; Williams, M. V. (1996) Mutagenesis of AS 52 cells by low concentrations of lead(II) and
mercury(II). Environ. Mol. Mutagen. 27: 30-33.
Ariza, M. E.; Williams, M. V. (1999) Lead and mercur y mutagenesis: type of mutation dependent upon metal

concentration. J. Biochem. Mol. Toxicol. 13: 107-112.
Ariza, M. E.; Bijur, G. N.; Williams, M. V. ( 1998a) Lead and mercury mutagenesis: role of H 2 

# O 2 

# , superoxide dismutase, and xanthine oxidase. Environ. Mol. Mutagen. 31: 352-361.
Arizono, K.; Sugiura, S.; Mi yazato, S.; Takiguchi, M.; Ariy oshi, T. (1996) DT-d iaphorase induction by lead acetate

in the liver of rats. Bull. Enviro n. Contam. Toxicol. 57: 41-46. Astrin, K. H.; Bishop, D. F.; Wetmur, J. G.; Kaul, B.; Davidow, B.; Desnick, R. J. (1987) δ -aminolevulinic acid
dehydratase isozymes and lead toxicity. In: Silbergeld, E. K.; Fowler, B. A., eds. Mechanisms of chemicalinduced porphyrinopathies. New York, NY: New York Academy of Sciences; pp. 23-29. (Annals of the New Yord Academy of Sciences: v. 514).

Attri, J.; Dhawan, V.; Mahmood, S.; Pandhi, P.; Parwana, H. K.; Nath, R. (2003) Effect of vitamin C
supplementation on oxidative DNA damage in an experimental model of lead-induced hypertension. Ann.

Nutr. Metab. 47: 294-301.
Audesirk, G.; Audesirk, T. (1991) Effects of inorganic lead on voltage-sensitive calcium channels in N1E-115
neuroblastoma cells. Neurotoxicology 12: 519-528. Aykin-Burns, N.; Laegeler, A.; Kellogg, G.; Ercal, N. (2003) Oxidative effects of lead in young and adult Fisher 344

rats. Arch. Environ. Contam. Toxicol. 44: 417-420.
Baginski, B.; Grube, B. (1991) Einfluß von blei, zink, und cadmium auf die zelltoxische wirkung humaner polymorphkerniger leukozyten am beispiel von hefzellen. Zentralbl. Hyg. Umweltmed. 191: 28-35.
Ban, M.; Hettich, D. (2005) Effect of Th2 cytokine antagonist treatments on chemical-induced allergic response in
mice. J. Appl. Toxicol. 25: 239-247. Bannon, D. I.; Olivi, L.; Bressler, J. (2000) The role of anion exchange in the uptake of Pb by human erythrocytes
and Madin-Darby canine kidney cells. Toxicology 147: 101-107. Baranowska-Bosiacka, I.; Hlynczak, A. J. (2003) The effe ct of lead ions on the energy metabolism of human
erythrocytes in vitro. Comp. Biochem. Physiol. Part C: Toxicol. Pharmacol. 134: 403-416.
Baranowska-Bosiacka, I.; Hlynczak, A. J. (2004) Effect of lead ions on rat erythrocyt e purine content. Biol. Trace

Elem. Res. 100: 259-273.
Barbier, O.; Jacquillet, G.; Tauc, M.; Cougnon, M.; Poujeol, P. (2005) Effect of heavy metals on, and handling by,
the kidney. Nephron. Physiol. 99: 105-110. Barltrop, D.; Smith, A. (1972) Lead binding to human haemoglobin. Experientia 28: 76-77.
Barnett, J. B. (1996) Developmental immunotoxicology. In. Smialowicz, R. J.; Holsapple, M. P., eds. Experimental
immunotoxicology. Boca Raton, FL: CRC Press, Inc.; 47-62.

Barnum-Huckins, K. M.; Martinez, A. O.; Rivera, E. V.; Adrian, E. K., Jr.; Herbert, D. C.; Weaker, F. J.;
Walter, C. A.; Adrian, G. S. (1997) A comparison of the suppression of human transferrin synthesis by lead
and lipopolysacchar ide. Toxicology 118: 11-22.

Barratt, C. L. R.; Davies, A. G.; Ba nsal, M. R.; Williams, M. E. (1989) The effects of lead on the male rat
reproductive system. Andrologia 21: 161-166.

Barthalmus, G. T.; Leander, J. D.; McMillan, D. E.; Mushak , P.; Krigman, M. R. (1977) Chronic effects of lead on schedule-controlled pigeon behavior. Toxicol. Appl. Pharmacol. 42: 271-284.

Ba ş aran, N.; Ündeger, Ü. (2000) Effects of lead on immune parameters in occupationally exposed workers. Am.

J. Ind. Med. 38: 349-354. Basha, M. R.; Wei, W.; Bakheet, S. A.; Benitez, N.; Siddiqi, H. K.; Ge, Y.-W.; Lahiri, D. K.; Zawia, N. H. (2005)
The fetal basis of amyloidogenesis: exposure to lead and latent overexpresson of amyloid precursor protein

and β -amyloid in the aging brain. J. Neurosci. 25: 823-829.

# AX5-192 Bataineh, H.; Al-Hamood, M. H.; Elbetieha , A. M. (1998) Assessment of aggressi on, sexual behavior and fertility in
adult male rat following long-term ingestion of four industrial metals salts. Human Exp. Toxicol.

17: 570-576.

Batetta, B.; Dessi, S.; Pulisci, D.; Carrucciu, A.; Pani, P. (1990) Multiple molecular forms of rat liver glucose-6-
phosphate dehydrogenase during liver hyperplasia induced by lead nitrate. Res. Commun. Chem. Pathol.

Pharmacol. 67: 279-288.

Batra, N.; Nehru, B.; Bansal, M. P. (2001) Influence of lead and zinc on rat male reproduction at 'biochemical and
histopathological levels'. J. Appl. Toxicol. 21: 507-512. Baykov, B.; Gunova, M.; Stoyanov, M.; Neychev, H.; Stefanova, T.; Nicolova, N. (1996) Designing an artificial
ecological mesocosm for the study of Cd and Pb impact on the immune system of experimental animals.

Toxicol Lett. 89: 5-10. Beach, J. R.; Henning, S. J. (1988) The di stribution of lead in milk and the fate of milk lead in th e gastrointestinal
tract of suckling rats. Pediatr. Res. 23: 58-62. Belloni-Olivi, L.; Annadata, M.; Goldstein, G. W.; Bressler, J. P. (1996) Phosphorylation of membrane proteins in
erythrocytes treated with lead. Biochem. J. 315: 401-406.
Bendich, A.; Belisle, E. H.; Strausser, H. R. (1981) Immune responses of rats chronically fed subclinical doses of lead. Clin. Exp. Immunol. 43: 189-194.
Bergdahl, I. A.; Grubb, A.; Schütz, A.; Desnick, R. J.; We tmur, J. G.; Sassa, S.; Skerfving, S. (1997) Lead binding

to δ -aminolevulinic acid dehydratase (ALAD) in human erythrocytes. Pharmacol. Toxicol. 81: 153-158. Bergdahl, I. A.; Sheveleva, M.; Schütz, A.; Artamonova, V. G.; Skerfving, S. (1998) Plasma and blood lead in
humans: capacity-limited binding to δ -aminolevulinic acid dehydratase an d other lead-binding components.

Toxicol. Sci. 46: 247-253. Bernard, A.; Lauwerys, R. (1987) Metal-induced alterations of δ -aminolevulinic acid dehydratase. In:
Silbergeld, E. K.; Fowler, B. A., eds. Mechanisms of chemical-induced porphyrinopathies. New York, NY:
New York Academy of Sciences; pp. 41-47. [Annals of the New York Academy of Sciences: v. 514]. Berry, W. D., Jr.; Moriarty, C. M.; Lau, Y. S. (2002) Lead attenuation of episodic growth hormone secretion in male

rats. Int. J. Toxicol. 21: 93-98.
Biedermann, K. A.; Landolph, J. R. (1987) Induction of anchorage independence in human diploid foreskin fibroblasts by carcinogenic metal salts. Cancer Res. 47: 3815-3823.
Biedermann, K. A.; Landolph, J. R. (1990) Role of va lence state and solubility of chromium compounds on
induction of cytotoxicity, mutagenesis, and anchorage independence in diploid human fibroblasts. Cancer

Res. 50: 7835-7842. Bielarczyk, H.; Tian, X.; Suszkiw, J. B. (1996) Cholinergic denervation-like changes in rat hippocampus following developmental lead exposure. Brain Res. 708: 108-115.
Bilban, M. (1998) Influence of the work environment in a Pb-Zn mine on the incidence of cytogenetic damage in

miners. Am. J. Ind. Med. 34: 455-463.

Bizarro, P.; Acevedok, S.; Niño-Cabrera , G.; Mussali-Galante, P.; Pasos, F.; Avila-Costa, M. R.; Fortoul, T. I.
(2003) Ultrastructural modifications in the mitochondri on of mouse Sertoli cells after inhalation of lead,
cadmium or lead-cadmium mixture. Reprod. Toxicol. 17: 561-566. Blackman, S. S., Jr. (1936) Intranuclear inclusion bodies in the kidney and liver caused by lead poisoning. Bull.
Johns Hopkins Hosp. 58: 384-402.
Blakley, B. R. (1987) The effect of lead on chemical- and viral-induced tumor production in mice. J. Appl. Toxicol.

7: 167-172. Blakley, B. R.; Archer, D. L. (1981) The effect of lead acetate on the immune response in mice. Toxicol. Appl.

Pharmacol. 61: 18-26. Blakley, B. R.; Sisodia, C. S.; Mukkur, T. K. (1980) Th e effect of methylmercury, tetraethyl lead, and sodium
arsenite on the humoral immune response in mice. Toxicol. Appl. Pharmacol. 52: 245-254.
Blankenship, L. J.; Carlisle, D. L.; Wise, J. P., Sr.; Orenstei n, J. M.; Dye, L. E., III; Patierno, S. R. (1997) Induction of apoptotic cell death by particulate lead chromate: differential effects of vitamins C and E on genotoxicity
and survival. Toxicol. Appl . Pharmacol. 146: 270-280.
Blanuša, M.; Kostial, K.; Piasek, M.; Jones, M. M.; Singh, P. K. (1995) Reduction of lead retention by mono-3- methylbutan-1-yl meso -2,3-dimercaptosuccinate in suckling rats. Analyst (Cambridge, U. K.) 120: 951-953.
Blazka, M. E.; Harry, G. J. ; Luster, M. I. (1994) Eff ect of lead acetate on nitrite production by murine brain endothelial cell cultures. Toxicol. Appl. Pharmacol. 126: 191-194.
Bogden, J. D.; Gertner, S. B.; Kemp, F. W.; McLeod, R. ; Bruening, K. S.; Chung, H. R. (1991) Dietary lead and
calcium: effects on blood pressure and renal neoplasia in Wistar rats. J. Nutr. 121: 718-728.

# AX5-193 Bogden, J. D.; Kemp, F. W.; Han, S. ; Murphy, M.; Fraiman, M.; Czerniach , D.; Flynn, C. J.; Banua, M. L.;
Scimone, A.; Castrovilly, L.; Gertner, S. B. (1995) Di etary calcium and lead interact to modify maternal blood pressure, erythropoiesis, and fetal and neonatal growth in rats during pregnancy and lactation. J. Nutr.

125: 990-1002. Bonacker, D.; Stoiber, T.; Böhm, K. J.; Prots, I.; Wang, M. ; Unger E.; Thier, R.; Bolt, H. M.; Degen, G. H. (2005) Genotoxicity of inorganic lead salts and disturbance of microtubule function. Environ. Mol. Mutagen.

45: 346-353. Bondy, S. C. (1986) Effect of triethyl lead chloride on δ -aminolevulinic acid dehydratase. J. Toxicol. Environ.

Health 18: 639-649.
Bondy, S. C. Guo, S. X. (1996) Lead potentiates iron-induced formation of reactive oxygen species. Toxicol. Lett.

87: 109-112. Borella, P.; Giardino, A. (1991) Lead and cadmium at very low doses affect in vitro immune response of human
lymphocytes. Environ. Res. 55: 165-177. Borg, C.; Abdelali, J.; Laderach, D.; Maruyama, K.; Waka sugi, H.; Charrier, S.; Ryffe l, B.; Vainchenker, W.;
Galy, A.; Caignard, A.; Zitvogel, L.; Cambi, A.; Figdor, C. (2004) NK cell ac tivation by dendritic cells
(DC) require the formation of a synapse leading to IL-12 polarization in DC. Blood 104: 3267-3275. Boscolo, P.; Carmignani, M.; Sacchetto ni-Logroscino, G.; Rannelletti, F. O. ; Artese, L.; Preziosi, P. (1988)
Ultrastructure of the testis in rats with blood hype rtension induced by long-ter m lead exposure. Toxicol.

Lett. 41: 129-137. Boudene, C.; Despaux-Pages, N.; Comoy, E.; Bohuon, C. (1984) Immunological and enzymatic studies of
erythrocytic δ -aminolevulinate dehydratase [Comparison of results obtained in normal and lead-exposed
subjects]. Int. Arch. Occup. Environ. Health 55: 87-96. Bouley, G.; Dubreuil, A.; Arsac, F.; Bo udène, C. (1977) Effet du plomb microparticulaire, introduit dans l'appareil
respiratoire, sur la sensibilité de la souris à l'infection par aérosol de Pasteurella multocida [Effect of
microparticulate lead, introduced thro ugh respiratory apparatus, on the re sistance of mice to infection by
aerosolized Pasteurella multocida]. C. R. Hebd. Seances Acad. Sci. Ser. D 285: 1553-1556.
Bourjeily, N.; Suszkiw, J. B. (1997) Developmental cholinot oxicity of lead: loss of septal cholinergic neurons and
long-term changes in cholinergic innervation of the hippocampus in perinatally lead-exposed rats. Brain

Res. 771: 319-328.
Bowen, W. H. (2001) Exposure to me tal ions and susceptibility to dental caries. J. Dent. Ed. 65: 1046-1053.
Boyce, S. J.; Mantle, T. J. (1993) Effect of lead acetate and carbon particles on the expression of glutathione Stransferase YfYf in rat liver. Biochem. J. 294: 301-304.
Bradbury, M. W.; Deane, R. (198 6) Rate of uptake of lead-203 into brain an d other soft tissues of the rat at constant radiotracer levels in plasma. Ann. N. Y. Acad. Sci. 481: 142-160.
Bradbury, M. W. B.; Deane, R. (1993) Permeability of the blood-brain barrier to lead. Neurotoxicology 14: 131-136.
Bradbury, M. W.; Lightman, S. L.; Yu en, L.; Pinter, G. G. (1991) Permeability of blood-brain and blood-nerve barriers in experimental diabetes mellitus in the anaesthetized rat. Exp. Physiol. 76: 887-898.
Braga, M. F. M; Pereira, E. F. R.; Albuquerque, E. X. (1999a) Nanomolar concentrations of lead inhibit
glutamatergic and GABAergic transmission in hippocampal neurons. Brain Res. 826: 22-34. Braga, M. F. M.; Pereira, E. F. R.; Marchioro, M.; Albuquerque, E. X. (1999b) Lead increases tetrodotoxininsensitive spontaneous release of glutamate and GA BA from hippocampal neurons . Brain Res. 826: 10-21.
Braga, M. F.; Pereira, E. F.; Mike, A.; Albuquerque, E. X. (2004) Pb2+ via protein kinase C inhibits nicotinic cholinergic modulation of synaptic transmission in the hippocampus. J. Pharmacol. Exp. Ther.

311: 700-710. Bratton, G. R.; Hiney, J. K.; Dees, W. L. (1994) Lead (Pb) alters the norepinephrine-induced secretion of luteinizing hormone releasing hormone from the medium eminence of adult male rats in vitro . Life Sci. 55: 563-571.
Bressler, J. P.; Goldstein, G. W. (1991) Mechanisms of lead neurotoxicity. Biochem. Pharmacol. 41: 479-484.
Brockel, B. J.; Cory-Slechta, D. A. (1998) Lead, attentio n, and impulsive behavior: changes in a fixed-ratio waitingfor-reward paradigm. Pharmacol. Biochem. Behav. 60: 545-552.
Brockel, B. J.; Cory-Slechta, D. A. (1999a) Lead-induced decrements in waiting behavior: involvement of D 2 

# -like
dopamine receptors. Pharmacol. Biochem. Behav. 63: 423-434. Brockel, B. J.; Cory-Slechta, D. A. (1999b) The effects of postweaning low-level Pb exposure on sustained
attention: a study of target densities, stimulus presen tation rate, and stimulus predictability. Neurotoxicology

20: 921-933. Brüschweiler, B. J.; Würgler, F. E.; Fent, K. (1996) I nhibitory effects of heavy metals on cytochrome P4501A
induction in permanent fish hepatoma cells. Arch. Environ. Contam. Toxicol. 31: 475-482.

# AX5-194 Buchet, J.-P.; Roels, H. E.; Hubermont , G.; Lauwerys, R. (1976) Effect of l ead on some parameters of the heme
biosynthetic pathway in rat tissues in vivo. Toxicology 6: 21-34. Buckley, J. D.; Robison, L. L.; Swotinsky, R.; Garabr ant, D. H.; LeBeau, M.; Manc hester, P.; Nesbit, M. E.;
Odom, L.; Peters, J. M.; Woods, W. G.; Hammond, G. D. (1989) Occupational exposures of parents of
children with acute nonlymphocytic leukemia: a report from the children's cancer study group. Cancer Res.

49: 4030-4037. Bunn, T. L.; Marsh, J. A.; Dietert, R. R. (2000) Gender differences in developmental immunotoxicity to lead in a
chicken: analysis following a single early low-level exposure in ovo. J. Toxicol. Environ. Health A

61: 677-693. Bunn, T. L.; Parsons, P. J.; Kao, E.; Dietert, R. R. (2001a) Gender-based profiles of developmental immunotoxicity
to lead in the rat: assessment in juveniles and adults. J. Toxicol. Environ. Health A 64: 223-240. Bunn, T. L.; Ladics, G. S.; Holsapple, M. P.; Dietert, R. R. (2001b) Developmental immunotoxicology assessment
in the rat: age, gender and strain comparisons af ter exposure to Pb. Toxicol. Methods 11: 41-58.

Bunn, T. L.; Parsons, P. J.; Kao, E.; Dietert, R. R. (2001c) Exposure to lead during critical windows of embryonic
development: differential immunotoxic outcome based on stage of exposure and gender. Toxicol. Sci.

64: 57-66. Burden, V. M.; Sandheinrich, M. B.; Caldwell, C. A. (1998) Effects of lead on the growth and δ -aminolevulinic acid
dehydratase activity of juvenile rainbow trout, Oncorhynchus mykiss . Environ. Pollut. 101: 285-289.
Burkey, R. T.; Nation, J. R. (1994) Brain stimulation re ward following chronic lead exposure in rats. Behav.

Neurosci. 108: 532-536.
Burright, R. G.; Engellenner, W. J.; Donovick, P. J. (1989) Postpartum aggression and plasma prolactin levels in
mice exposed to lead. Physiol. Behav. 46: 889-893. Burstein, H. J.; Tepper, R. I.; Leder, P.; Abbas, A. K. (1991) Humoral immune functions in IL-4 transgenic mice.

J. Immunol. 147: 2950-2956.
Cai, M. Y.; Arenaz, P. (1998) Antimu tagenic effect of crown ethers on heavy metal-induced sister chromatid exchanges. Mutagenesis 13: 27-32.
Calabrese, E. J.; Baldwin, L. A. (1992) Lead-induced cell proliferation and organ-specific tumorigenicity. Drug

Metab. Rev. 24: 409-416.

Calabrese, E. J.; Baldwin, L. A.; Leonar d, D. A.; Zhao, X. Q. (1995) Decrease in hepatotoxicity by lead exposure is
not explained by its mitogenic response. J. Appl. Toxicol. 15: 129-132.
Calderón-Salinas, J. V.; Quintanar-Esco rza, M. A.; Hernández-Luna, C. E. ; González-Martínez, M. T. (1999a) Effect of lead on the calcium transport in human erythrocyte. Hum. Exp. Toxicol. 18: 146-153.
Calderón-Salinas, J. V.; Quintanar-Esco rcia, M. A.; González-Ma rtínez, M. T.; Hernánd ez-Luna, C. E. (1999b) Lead and calcium transport in human erythr ocyte. Hum. Exp. Toxicol. 18: 327-332.

Camoratto, A. M.; White, L. M.; Lau, Y.-S.; Ware, G. O.; Be rry, W. D.; Moriarty, C. M. (1993) Effect of exposure
to low level lead on growth and growth hormone release in rats. Toxicology 83: 101-114.

Carballido, J. M.; Schols, D.; Namikawa, R.; Zurawski, S.; Zu rawski, Z.; Roncarolo, M. G. ; de Vries, J. E. (1995)
IL-4 induces human B cell maturation and IgE synthesis in SCID-hu mice. Inhibition of ongoing IgE
production by in vivo treatment with an IL-4/IL-13 receptor antagonist. J. Immunol. 155: 4162-4170.

Cardenas, A.; Roels, H.; Bernard, A. M.; Barbon, R.; Buchet, J. P.; Lauwerys, R. R.; Rosello, J.; Ramis, I.; Mutti,

A.; Franchini, I.; Fels, L. M.; Stolte, H.; De Broe, M. E.; Nuyts, G. D.; Taylor, S. A.; Price, R. G. (1993)
Markers of early renal changes induced by industrial pollutants. II. Application to workers exposed to lead.

Br. J. Ind. Med. 50: 28-36.
Cardinale, F.; de Benedictis, F. M.; Muggeo, V.; Giordana, P.; Loffredo, M. S.; Iacovie llo, G.; Armenio, L. (2005)
Exhaled nitric oxide, total serum IgE and allergic sensitization in childhood asthma and allergic rhinitis. Pediatr. Allergy Immunol. 16: 236-242.
Carey, J. B.; Allshire, A.; Van Pelt, F. N. (2006) Immune modulation by cadmium and lead in the acute reporter
antigen-popliteal lymph node assay. Toxicol. Sci. 91: 113-122. Carmignani, M.; Boscolo, P.; Poma, A.; Volpe, A. R. (1999) Kininergic system and arterial hypertension following
chronic exposure to inorganic lead. Immunopharmacology 44: 105-110.
Carmignani, M.; Volpe, A. R.; Boscolo, P.; Qiao, N.; Gio acchino, M. Di; Grilli, A.; Fela co, M. (2000) Catcholamine and nitric oxide systems as targets of chronic lead exposure in inducing selective functional impairment.

Life Sci. 68: 401-415. Carsia, R. V.; Forman, D.; Hock, C. E.; Nagele, R. G.; Mc Ilroy, P. J. (1995) Lead alters growth and reduces
angiotensin II receptor density of rat aortic smooth mu scle cells. Proc. Soc. Exp. Biol. Med. 210: 180-190.

# AX5-195 Castranova, V.; Bowman, L.; Reasor, M. J.; Miles, P. R. (1980) Effects of heavy metal ions on selected oxidative
metabolic processes in rat alveolar macrophages. Toxicol. Appl. Pharmacol. 53: 14-23.

Celotti, L.; Furlan, D.; Seccati, L.; Levi s, A. G. (1987) Interactions of nitrilotri acetic acid (NTA) with Cr(VI)
compounds in the induction of gene mutations in cultured mammalian cells. Mutat. Res. 190: 35-39.
Chai, S.; Webb, R. C. (1988) Effects of lead on vascular reactivity. Environ. Health Perspect. 78: 85-89. Chakraborty, I.; Sharma, A.; Talukder, G. (1987) Antagonistic and synergistic effects of lead and selenium in Rattus
norvegicus . Toxicol. Lett. 37: 21-26.
Chang, H.-R.; Chen, S.-S.; Chen, T.-J.; Ho, C.-K.; Chiang, H.-C.; Yu, H.-S. (1996) Lymphocyte β 2 

# -adrenergic receptors and plasma catecholamine leve ls in lead-exposed workers. Toxi col. Appl. Pharmacol. 139: 1-5.
Chang, H.-R.; Chen, S.-S.; Tsao, D.-A.; Cheng, J. -T.; Ho, C.-K.; Yu, H.-S. (1997) Change of cardiac β

adrenoceptors in lead-exposed rats. Toxicology 123: 27-32. Chang, H.-R.; Tsao, D.-A.; Yu, H.-S.; Ho, C.-K. (2005) The change of β -adrenergic system after cessation of lead
exposure. Toxicology 207: 73-80. Chaurasia, S. S.; Gupta, P.; Maiti, P. K.; Kar, A. (1998) Possible involvement of lipid peroxidation in the inhibition
of type I iodothyronine 5'-monodeiodinase activity by lead in chicken liver. J. Appl. Toxicol. 18: 299-300.
Chen, H.-H.; Ma, T.; Paul, I. A.; Spencer, J. L.; Ho, I. K. (1997a) Developmental lead exposure and two-way active avoidance training alter the distribution of protein kinase C activity in the rat hippocampus. Neurochem.

Res. 22: 1119-1125.

Chen, S.; Miller, T. E.; Golemboski, K. A.; Dietert, R. R. (1997b) Suppress ion of macrophage metabolite production by lead glutamate in vitro is reversed by meso-2,3-dimercaptosu ccinic acid (DMSA). In Vitro Toxicol.

10: 351-358.

Chen, S.; Golemboski, K. A.; Sanders, F. S.; Dietert, R. R. (1999) Persistent effect of in utero meso-2,3- dimercaptosuccinic acid (DMSA) on immune function and lead-induced immunotoxicity. Toxicology

132: 67-79. Chen, H.; Ma, T.; Ho, I. K. (2001) Effects of developmental lead exposure on inhibitory avoidance learning and glutamate receptors in rats. Environ. Toxicol. Pharmacol. 9: 185-191.
Chen, S. C.; Golemboski, K. A.; Piepenbrink, M.; Dietert, R. R. (2004) Developmental immunotoxicity of lead in

the rat: influence of maternal diet. J. Toxi col. Environ. Health Part A 67: 495-511. Cheng, Y.; Willett, W. C.; Schwartz, J. ; Sparrow, D.; Weiss, S.; Hu, H. (1998) Relation of nutrition to bone lead and
blood lead levels in middle-aged to elderly men. The Normative Aging Study. Am. J. Epidemiol.

147: 1162-1174. Cheng, Y.-J.; Yang B.-C.; Hsieh, W.-C.; Huang, B.-M.; Liu, M.-Y. (2002) Enhancement of TNF- α expression does
not trigger apoptosis upon exposure of glial cells to lead and lipopolysaccharide. Toxicology 178: 183-191. Chia, K. S.; Mutti, A.; Tan, C.; Ong, H. Y.; Jeyaratnam, J.; Ong, C. N.; Lee, E. (1994 ) Urinary N-acetyl- β

- D



# glucosaminidase activity in workers exposed to inorganic lead. Occup. Environ. Med. 51: 125-129.

Chmielnicka, J.; Zar ę ba, G.; Nasiadek, M. (1994) Combin ed effect of tin and lead on heme biosynthesis in rats.

Ecotoxicol. Environ. Saf. 29: 165-173.
Choie, D. D.; Richter, G. W. (1972) Lead poisoning: rapid formation of intranuclear inclusions. Science
(Washington, DC) 177: 1194-1195. Choie, D. D.; Richter, G. W.; Young, L. B. (1975) Biogenesis of intranuclear lead-protein inclusions in mouse
kidney. Beitr. Pathol. 155: 197-203.
Chowdhuri, D. K.; Narayan, R.; Saxena, D. K. (2001) Effect of lead and chromium on nucleic acid and protein synthesis during sperm-zona binding in mice. Toxicol. In Vitro 15: 605-613.
Chowdhury, A. R.; Dewan, A.; Gandhi, D. N. (1984) Toxic effect of lead on the testes of rat. Biomed. Biochim.

Acta 43: 95-100. Chowdhury, A. R.; Rao, R. V.; Gautam, A. K. (1986) Histochemical changes in th e testes of lead induced
experimental rats. Folia Histochem. Cytobiol. 24: 233-237.
Chowdhury, A. R.; Rao, R. V.; Gautam, A. K.; Kashyap, S. K. (1987) Functional changes of testes in lead

intoxicated rats. Ind. Health 25: 55-62.
Church, H. J.; Day, J. P.; Braithwaite, R. A.; Brown, S. S. (1993a) Binding of lead to a metallothionein-like protein
in human erythrocytes. J. Inorg. Biochem. 49: 55-68. Church, H. J.; Day, J. P.; Braithwaite, R. A.; Brown, S. S. (1993b) The speciation of lead in erythrocytes in relation
to lead toxicity: case studies of two lead-exposed workers. Neurotoxicology 14: 359-364.
Claudio, L.; Lee, T.; Wolff, M. S.; Wetmur, J. G. (1 997) A murine model of genetic susceptibility to lead
bioaccumulation. Fundam. Appl. Toxicol. 35: 84-90.

# AX5-196 Cline, H. T.; Witte, S.; Jones, K. W. (1996) Low lead levels stunt neuronal growth in a reversible manner. Proc.

Natl. Acad. Sci. U. S. A. 93: 9915-9920. Cocco, P.; Carta, P.; Flore, C.; Congia, P.; Manca, M. B. ; Saba, G.; Salis, S. (1996) Mortality of lead smelter
workers with the glucose-6-phosphate dehydrogenase-deficient phenotype. Cancer Epidemiol. Biomarkers

Prev. 5: 223-225.

Cocco, P.; Dosemeci, M.; Heineman, E. F. (1998) Brain cancer and occupati onal exposure to lead. J. Occup.

Environ. Med. 40: 937-942.
Coffigny, H.; Thoreux-Manlay, A.; Pinon-Lataillade, G.; M onchaux, G.; Masse, R.; Soufir, J.-C. (1994) Effects of lead poisoning of rats during pregnancy on the reproductive system and fertility of their offspring. Hum.
Exp. Toxicol. 13: 241-246.
Cohen, N.; Modai, D.; Golik, A.; Weissgarten, J.; Peller, S.; Katz, A.; Averbukh, Z.; Sh aked, U. (1989) Increased concanavalin A-induced suppressor cell activity in huma ns with occupational lead exposure. Environ. Res.

48: 1-6. Cohn, J.; Cory-Slechta, D. A. (1993) Subsensitivity of lead -exposed rats to the accuracy-impairing and rate-altering
effects of MK-801 on a multiple schedule of repeat ed learning and performance. Brain Res. 600: 208-218.
Cohn, J.; Cory-Slechta, D. A. (1994a) Assessment of the role of dopaminergic systems in lead-induced learning impairments using a repeated acquisition and performance baseline. Neurotoxicology 15: 913-926.
Cohn, J.; Cory-Slechta, D. A. (1994b) Lead exposure po tentiates the effects of NMDA on repeated learning.

Neurotoxicol. Teratol. 16: 455-465. Cohn, J.; Cox, C.; Cory-Slechta, D. A. (1993) The effects of lead exposure on learni ng in a multiple repeated
acquisition and performance schedule. Presented at: Ninth international neurotoxicology conference;
October 1991; Little Rock, AR. Neurotoxicology 14(2-3): 329-346.
Cole, L. J.; Bachhuber, L. J. (1915) The ef fect of lead on the germ cells of th e male rabbit and fowl as indicated by
their progeny. Proc. Soc. Exp. Biol. Med. 12: 24-29.

Columbano, A.; Ledda-Columbano, G. M. ; Coni, P.; Pani, P. (1987) Failure of mitogen-induced cell proliferation to achieve initiation of rat liver carcinogenesis. Carcinogenesis 8: 345-347.

Columbano, A.; Ledda-Columbano, G. M. ; Ennas, M. G.; Curto, M.; de Mon tis, M. G.; Roomi, M. W.; Pani, P.;
Sarma, D. S. R. (1988) Modulation of the activity of hepatic gamma-glutamyl transpeptidase, adenosine triphosphatase, placental glutathione S-transferase and adenylate cyclase by acute administration of lead
nitrate. Basic Appl. Histochem. 32: 501-510.

Columbano, A.; Ledda-Columbano, G. M. ; Ennas, M. G.; Curto, M.; Chelo, A. ; Pani, P. (1990) Cell proliferation and promotion of rat liver carcinogenesis: different effect of hepatic regeneration and mitogen induced
hyperplasia on the development of enzyme-altered foci. Carcinogenesis 11: 771-776. Columbano, A.; Endoh, T.; Denda, A.; Noguchi, O.; Nakae, D.; Hasegawa, K.; Ledda-Columbano, G. M.;
Zedda, A. I.; Konishi, Y. (1996) Effects of cell prolif eration and cell death (apoptosis and necrosis) on the
early stages of rat hepatocarcinog enesis. Carcinogenesis 17: 395-400. Coni, P.; Bignone, F. A.; Pichiri, G. ; Ledda-Columbano, G. M.; Columbano, A.; Rao, P. M.; Rajalakhmi, S.;
Sarma, D. S. (1989) Studies on the kinetics of expression of cell cycle dependent proto-oncogenes during
mitogen-induced liver cell proliferation. Ca ncer Lett. (Shannon, Irel.) 47: 115-119. Coni, P.; Pichiri-Coni, G.; Ledda-Columbano, G. M.; Semple, E.; Rajalakshmi, S.; Rao, P. M.; Sarma, D. S. R.;
Columbano, A. (1992) Stimulation of DNA synthesis by rat plasma following in vivo treatment with three
liver mitogens. Cancer Lett. 61: 233-238. Coni, P.; Simbula, G.; De Prati, A. C.; Menegazzi, M.; Suzuki, H.; Sarma, D. S. R. ; Ledda-Columbano, G. M.;
Columbano, A. (1993) Differ ences in the steady-state levels of c-fos, c-jun and c-myc messenger RNA
during mitogen-induced liver growth and compensatory regeneration. Hepatology (Baltimore)

17: 1109-1116. Connor, T. H.; Pier, S. M. (1990) Reduction of the mutagenicity of lead chromate-based pigments by encapsulation

with silica. Mutat. Res. 245: 129-133.
Cook, J. A.; Hoffmann, E. O.; Di Luzio, N. R. (1975) Infl uence of lead and cadmium on the susceptibility of rats to
bacterial challenge. Proc. Soc. Exp. Biol. Med. 150: 741-747.
Cook, L. R.; Stohs, S. J.; Angle, C. R.; Hickman, T. I.; Maxell, R. C. (1987) Erythrocyte membrane microviscosity and phospholipid composition in lead workers. Br. J. Ind. Med. 44: 841-844.
Cooper, G. P.; Manalis, R. S. (1984) Interactions of lead and ca dmium on acetylcholine release at the frog neuromuscular junction. Toxicol. Appl. Pharmacol. 74: 411-416.
Corchs, J.; Gioia, I. A.; Serrani, R. E.; Taborda, D. (2001) Lead ions but not other metallic ions increase resistance
to hypotonic lysis in prenatal hemopoiesis red blood cells. Biocell 25: 287-289.

# AX5-197 Corpas, I.; Gaspar, I.; Martínez, S.; Codesa l, J.; Candelas, S.; Antonio, M. T. (1995) Testicular alterations in rats due
to gestational and early lactational administration of lead. Reprod. Toxicol. 9: 307-313. Corpas, I.; Benito, M. J.; Marquina, D.; Castillo, M.; Lopez, N.; Antonio, M. T. (2002a) Gestational and lactational
lead intoxication produces alterations in the hepatic system of rat pups. Ecotoxicol. Environ. Saf. 51: 35-43.
Corpas, I.; Castillo, M.; Marquina, D.; Benito, M. J. (2002b) Lead intoxication in gestational and lactation periods alters the development of male reproductive organs. Ecotoxicol. Environ. Saf. 53: 259-266.

Cortina-Ramírez, G. E.; Cerbón-S olorzano, J.; Calderón-Salinas, J. V. (2006) Effects of 1,25-
dihydroxicolecalciferol and dietary cal cium—phosphate on distribution of lead to tissues during growth. Toxicol. Appl. Pharmacol. 210: 123-127.
Cory-Slechta, D. A. (1986) Prolonged lead exposure and fixed ratio performance. Neurobehav. Toxicol. Teratol.

8: 237-244. Cory-Slechta, D. A. (1988) Mobilization of lead over the course of DMSA chelation therapy and long-term efficacy.
J. Pharmacol. Exp. Ther. 246: 84-91. Cory-Slechta, D. A. (1990a) Exposure duration modifies the effects of low level lead on fixed-interval performance.
Neurotoxicology 11: 427-441.
Cory-Slechta, D. A. (1990b) Lead exposure during advanced age: alterations in kinetics and biochemical effects. Toxicol. Appl. Pharmacol. 104: 67-78.
Cory-Slechta, D. A. (1990c) Alterations in tissue Pb distribution and hematopoietic indices during advanced age.

Arch. Toxicol. 64: 31-37. Cory-Slechta, D. A. (1994) Neurotoxicant-induced changes in schedule-controlled behavior. In: Chang, L. W., ed.
Principles of neurotoxicology. New York, NY: Marcel Dekker, Inc.; pp. 313-344. (Neurological disease and
therapy: v. 26). Cory-Slechta, D. A. (1995) MK-801 subsensitivity fo llowing postweaning lead exposure. Neurotoxicology

16: 83-95. Cory-Slechta, D. A. (1997) Postnatal lead exposure and MK-801 sensitivity. Neurotoxicology 18: 209-220. Cory-Slechta, D. A. (2003) Lead-induced impairments in complex cognitive function: offerings from experimental
studies. Child Neuropsychol. 9: 54-75.
Cory-Slechta, D. A.; Pokora, M. J. (1991) Behavioral manifestations of prolonged lead exposure initiated at different stages of the life cycle. 1. Schedule-controlled responding. Neurotoxicology 12: 745-760.
Cory-Slechta, D. A.; Pokora, M. J. (1995) Lead-induced changes in muscarinic cholinergic sensitivity.
Neurotoxicology 16: 337-347. Cory-Slechta, D. A.; Thompson, T. (1979) Behavioral toxicity of chronic postweaning lead exposure in the rat.
Toxicol. Appl. Pharmacol. 47: 151-159. Cory-Slechta, D. A.; Weiss, B. (1989) Efficacy of the chelating agent CaEDTA in reversing lead-induced changes in
behavior. Neurotoxicology 10: 685-697.
Cory-Slechta, D. A.; Widzowski, D. V. (1991) Low leve l lead exposure increases sensitivity to the stimulus properties of dopamine D 1 

# and D 2 

# agonists. Brain Res. 553: 65-74.
Cory-Slechta, D. A.; Weiss, B.; Cox, C. (1983) Delayed behavioral toxicity of lead with increasing exposure
concentration. Toxicol. Appl. Pharmacol. 71: 342-352. Cory-Slechta, D. A.; Weiss, B.; Cox, C. (1985) Performance and exposure indices of rats exposed to low
concentrations of lead. Toxicol. Appl. Pharmacol.78: 291-299.
Cory-Slechta, D. A.; Weiss, B.; Cox, C. (1987) Mobiliza tion and redistribution of lead over the course of calcium disodium ethylenediamine tetraacetat e chelation therapy. J. Pharmaco l. Exp. Ther. 243: 804-813.
Cory-Slechta, D. A.; Weiss, B.; Cox, C. (1989) Tissue distribution of Pb in adult vs. old rats: a pilot study.
Toxicology 59: 139-149. Cory-Slechta, D. A.; Pokora, M. J.; Widzowski, D. V. (1991) Behavioral manifestations of prolonged lead exposure
initiated at different stages of the life cycle. II. De layed spatial alternation. Neurotoxicology 12: 761-776.
Cory-Slechta, D. A.; Pokora, M. J.; Widzowski, D. V. (199 2) Postnatal lead exposure induces supersensitivity to the stimulus properties of D 2 

# -D 3 

# agonist. Brain Res. 598: 162-172.
Cory-Slechta, D. A.; Pokora, M. J.; Jo hnson, J. L. (1996a) Postweaning lead exposure enhances the stimulus
properties of N-methyl-D-aspartate: possible dopaminergic involvement? Neurotoxicology 17: 509-521. Cory-Slechta, D. A.; Pokora, M. J.; Pr eston, R. A. (1996b) The effects of dopamine agonists on fixed interval
schedule-controlled behavior are selectively altered by low-level lead exposure. Neurotoxicol. Teratol.

18: 565-575. Cory-Slechta, D. A.; Pokora, M. J.; Fox, R. A. V.; O'Mara, D. J. (1996c) Lead-induced changes in dopamine D 1 

# sensitivity: modulation by drug discriminati on training. Neurotoxicology. 17: 445-457.

# AX5-198 Cory-Slechta, D. A.; McCoy, L.; Richfield, E. K. (1997a) Time course and regional basis of Pb-induced changes in
MK-801 binding: reversal by chronic treatment w ith the dopamine agonist apomorphine but not the D 1 

# agonist SKF-82958. J. Neurochem. 68: 2012-2023.
Cory-Slechta, D. A.; Garcia-Osuna, M.; Greenamyre, J. T. (1997b) Lead-induced ch anges in NMDA receptor
complex binding: correlations with l earning accuracy and with sensitivity to learning impairments caused by

MK-801 and NMDA administration. Behav. Brain Res. 85: 161-174.
Cory-Slechta, D. A.; O'Mara, D. J.; Brockel, B. J. (1998) Nucleus accumben s dopaminergic medication of fixed
interval schedule-controlled behavior and its modulation by low-level lead exposure. J. Pharmacol. Exp.

Ther. 286: 794-805.
Cory-Slechta, D. A.; Brockel, B. J.; O'Mara, D. J. (2002) Lead exposure and dorsomedial striatum mediation of
fixed interval schedule-controlled behavior. Neurotoxicology 23: 313-327. Cory-Slechta, D. A.; Virgolini, M. B.; Thiruchelvam, M. ; Weston, D. D.; Bauter, M. R. (2004) Maternal stress
modulates the effects of developmental lead exposure. Environ. Health Perspect. 112: 717-730. Costa, M.; Zhitkovich, A.; Gargas, M. ; Paustenbach, D.; Finley, B.; Kuykenda ll, J.; Billings, R.; Carlson, T. J.;
Wetterhahn, K.; Xu, J.; Patierno, S.; Bogdanffy, M. (1 996) Interlaboratory validation of a new assay for
DNA-protein crosslinks. Mutat. Res. 369: 13-21. Courtois, E.; Marques, M.; Barrientos, A.; Casado, S.; López-Farré, A. (2003) Lead-induced downregulation of
soluble guanylage cyclase in isolat ed rat aortic segments mediated by reactive oxygen species and
cyclooxygenase-2. J. Am. Soc. Nephrol. 14: 1464-1470.
Craan, A. G.; Nadon, G.; P'an, A. Y. (1984) Lead flux through the kidney and salivary glands of rats. Am.
J. Physiol. 247: F773-F783.
Cramer, K.; Goyer, R. A.; Jagenburg, R. ; Wilson, M. H. (1974) Renal ultrastr ucture, renal function, and parameters of lead toxicity in workers with different periods of lead exposure. Br. J. Ind. Med. 31: 113-127.
Cremin, J. D., Jr.; Luck, M. L.; Laugh lin, N. K.; Smith, D. R. (1999) Efficacy of succimer chelation for reducing
brain lead in a primate model of human lead exposure. Toxicol. Appl. Pharmacol. 161: 283-293. Cremin, J. D., Jr.; Luck, M. L.; Laughlin, N. K.; Smith, D. R. (2001) Oral succimer decr eases the gastrointestinal
absorption of lead in juvenile monkeys. Environ. Health Perspect. 109: 613-619.
Crowe, A.; Morgan, E. H. (1996) Interactions between tissu e uptake of lead and iron in normal and iron-deficient rats during development. Biol. Trace Elem. Res. 52: 249-261.
Curzon, M. E. J.; Bibby, B. G. (1970) Effect of heavy metals on dental caries and tooth eruption. J. Dent. Child.

37: 463-465. Daggett, D. A.; Nuwaysir, E. F.; Nelson, S. A.; Wright, L. S.; Kornguth, S. E.; Siegel, F. L. (1997) Effects of
triethyl lead administration on the expression of glutathione S-transferase isoenzymes and quinone reductase in rat kidney and liver. Toxicology 117: 61-71.
Daggett, D. A.; Oberley, T. D.; Nelson, S. A.; Wright, L. S.; Kornguth, S. E.; Si egel, F. L. (1998) Effects of lead on
rat kidney and liver: GST expression and oxidative stress. Toxicology 128: 191-206. Danadevi, K.; Rozati, R.; Saleha Banu, B.; Hanumanth R. P.; Grover, P. (2003) DNA damage in workers exposed to
lead using comet assay. Toxicology 187: 183-193.
Dantzer, R.; Bluthé, R. M.; Gheusi, G.; Cremona, S.; Layé, S.; Parnet, P.; Kelley, K. W. (1998) Molecular basis of

sickness behavior. Ann. N.Y. Acad. Sci. 856: 132-138.

De, M.; Ghosh, S.; Palit, S.; Ghosh, A.; Talukder, G.; Sharma, A. (1995) Clastogenic effects in human samples
following prolonged exposure in metal industry. Bull. Environ. Contam. Toxicol. 54: 357-362. De Guise, S.; Bernier, J.; Lapierre, P. ; Dufresne, M. M.; Dubreuil, P.; Fornier, M. (2000) Immune function of bovine
leukocytes after in vitro exposure to selected heavy metals. Am. J. Vet. Res. 61: 339-344.

De la Fuente, H.; Portales-Pérez, D.; Baranda, L.; Díaz-Ba rriga, F.; Saavedra-Alanís, V.; Layseca, E.; GonzálezAmaro, R. (2002) Effect of arsenic, cadmium and l ead on the induction of apoptosis of normal human
mononuclear cells. Clin. Exp. Immunol. 129: 69-77.
De Marco, M.; Halpern, R.; Barros, H. M. T. (2005) Early be havioral effects of lead perinatal exposure in rat pups. Toxicology 211: 49-58.
De Vries, I.; Spaans, E.; Van Dijk, A.; Meulenbelt, J. (1998) Lead toxicokinetics. Development of a biokinetic
model to understand and predict the outcome of treatment. Przegl. Lek. 55: 500-504. Dearth, R. K.; Hiney, J. K.; Srivastava, V.; Burdick, S. B.; Bratton, G. R.; Dees, W. L. (2002) Effects of lead (Pb)
exposure during gestation and lactation on female pubertal development in the rat. Reprod. Toxicol.

16: 343-352.

# AX5-199 Dearth, R. K.; Hiney, J. K.; Srivastava , V.; Les Dees, W.; Bratton, G. R. (2004) Low level lead (Pb) exposure during
gestation and lactation: assessment of effects on pubertal development in Fisher 344 and Sprague-Dawley

female rats. Life Sci. 74: 1139-1148.
Degawa, M.; Arai, H.; Miura, S.; Hashimoto, Y. (1993) Pr eferential inhibitions of hepatic P450IA2 expression and
induction by lead nitrate in the rat. Carcinogenesis (London) 14: 1091-1094. Degawa, M.; Arai, H.; Kubota, M.; Hash imoto, Y. (1994) Ionic lead, a uniq ue metal ion as an inhibitor for
cytochrome P450IA2 (CYP1A2) expression in the rat liver. Biochem. Biophys. Res. Commun.

200: 1086-1092. Degawa, M.; Arai, H.; Kubota, M.; Hashimoto, Y. (1995) Ionic lead, but not other ionic metals (Ni2+, Co2+ and
Cd2+), suppresses 2-methoxy-4-aminoazobenzene-mediated cytochrome P450IA2 (CYP1A2) induction in

rat liver. Biol. Pharm. Bull. 18: 1215-1218. Degawa, M.; Matsuda, K.; Arai, H.; Hashimoto, Y. (1996) Le ad nitrate inhibits the induction of CYP1A mRNAs by
aromatic amines but not by aryl hydrocarbons in the rat liver. J. Biochem. (Tokyo, Jpn.) 120: 547-551. Dehpour, A. R.; Essalat, M.; Ala, S.; Ghazi-Khansari, M.; Ghafourifar, P. (1999) Increase by NO synthase inhibitor

of lead-induced release of N -acetyl- β -D-glucosaminidase from perfused rat kidney. Toxicology

132: 119-125. Dekaney, C. M.; Harris, E. D.; Bratton, G. R.; Jaeger, L. A. (1997) Lead transport in IE C-6 intestinal epithelial cells.

Biol. Trace Elem. Res. 58: 13-24.
Delville, Y. (1999) Exposure to lead during development alters aggressive behavior in golden hamsters.

Neurotoxicol. Teratol. 21: 445-449.
Deng, W.; Poretz, R. D. (2002) Protein kinase C activ ation is required for the lead-induced inhibition of
proliferation and differentiation of cultured oligoden droglial progenitor cells. Brain Res. 929: 87-95. Deng, W.; McKinnon, R. D.; Poretz, R. D. (2001) Lead exposure delays the differentiation of oligodendroglial
progenitors in vitro. Toxicol. Appl. Pharmacol. 174: 235-244.

Dentener, M. A.; Greve, J. W.; Maessen, J. G.; Buurman, W. A. (1989) Role of tumour necrosis factor in the enhanced sensitivity of mice to endotoxin after exposure to lead. Immunopharmacol. Immunotoxicol.

11: 321-334.
Dessi, S.; Batetta, B.; Laconi, E.; Ennas, C.; Pani, P. (1 984) Hepatic cholesterol in lead nitrate induced liver hyperplasia. Chem. Biol. Interact. 48: 271-279.

Dessi, S.; Batetta, B.; Pulisci, D.; Carrucci u, A.; Mura, E.; Ferreli, A.; Pani, P. (1990) Modifying influence of fasting
on liver hyperplasia induced by l ead nitrate. Res. Commun. Chem. Pathol. Pharmacol. 68: 103-116.
Devi, K. D.; Banu, B. S.; Grover, P.; Jamil, K. (2000) Ge notoxic effect of lead nitr ate on mice using SCGE (comet
assay). Toxicology 145: 195-201. Dey, S.; Arjun, J.; Das, M.; Bhattacharj ee, C. R.; Dkhar, P. S. (2001) Effect of prenatal lead toxicity on surface
ultrastructural features, elemental composition and infrar ed absorption characteristics of the skin of albino
mice. Cytobios 106(suppl. 2): 245-254. Dhir, H.; Roy, A. K.; Sharma, A.; Talukder, G. (1990) Mo dification of clastogenicity of lead and aluminium in
mouse bone marrow cells by dietary ingestion of Phyllanthus emblica fruit extract. Mutat. Res.

241: 305-312.
Dhir, H.; Ghosh, S.; Sharma, A.; Talukder, G. (1992a) Interaction between two group IV metals: - lead and

zirconium - in bone marrow cells of Mus musculus in vivo. Biometals 5: 81-86.
Dhir, H.; Sharma, A.; Talukder, G. (1992b) Modifying effect of iron on lead-induced clastogenicity in mouse bone

marrow cells. Biol. Trace Elem. Res. 34: 279-286.
Dhir, H.; Roy, A. K.; Sharma, A. (1993) Relative efficiency of Phyllanthus emblica fruit extract and ascorbic acid in
modifying lead and aluminium-induced sister-chromatid exchanges in mouse bone marrow. Environ. Mol.
Mutagen. 21: 229-236. Diamond, G. L.; Goodrum, P. E.; Felter, S. P.; Ruoff, W. L. (1998) Gastrointestinal absorption of metals. Drug

Chem. Toxicol. 21: 223-251.

Dieter, M. P.; Matthews, H. B.; Jeffcoat, R. A.; Moseman, R. F. (1993) Comparison of lead bioavailability in F344

rats fed lead acetate, lead oxide, lead sulfide, or l ead ore concentrate from Skag way, Alaska. J. Toxicol.

Environ. Health 39: 79-93. Dietert, R. R.; Piepenbrink, M. S. (2006) Perinatal immu notoxicity: why adult exposure assessment fails to predict
risk. Environ. Health Perspect. 114: 477-483.

Dietert, R. R.; Etzel, R. A.; Chen, D.; Halonen, M.; Hollada y, S. D.; Jarabek, A. M.; Landreth, K.; Peden, D. B.;
Pinkerton, K.; Smialowicz, R. J.; Zoetis, T. (2000) Workshop to identify critical window of exposure for

# AX5-200 children's health: immune and respiratory systems work group summary. Environ. Health Perspect. Suppl.
108(3): 483-490. Dietert, R. R.; Lee, J.-E.; Bunn, T. L. (2002) Developmental immunotoxicology: emerging issues. Hum. Exp.

Toxicol. 21: 479-485.
Dietert, R. R.; Lee, J.-E.; Hussain, I.; Piepenbrink, M. (2004) Developmental immunotoxicology of lead. Toxicol. Appl. Pharmacol. 86-94.
Ding, Y.; Vaziri, N. D.; Gonick, H. C. (1998) Lead-induced hypertension. II. Response to sequential infusions of
L-arginine, superoxide dismutase, and nitroprusside. Environ. Res. 76: 107-113. Ding, Y.; Gonick, H. C.; Vaziri, N. D. (2000) Lead promotes hydroxyl radical generation and lipid peroxidation in
cultured aortic endothelial cells. Am. J. Hypertens. 13: 552-555.
Ding, Y.; Gonick, H. C.; Vaziri, N. D.; Liang, K.; Wei, L. (2001) Lead-induced hypertension. III. Increased hydroxyl radical production. Am. J. Hypertens. 14: 169-173.

Dini, L.; Falasca, L.; Lentini, A.; Ma ttioli, P.; Piacentini, M.; Piredda, L.; Autuori, F. (1993) Galactose-specific receptor modulation related to the onset of apoptosis in rat liver. Eur. J. Cell. Biol. 61: 329-337.

Dini, L.; Giudetti, A. M.; Ruzittu, M.; Gnoni, G. V.; Zara , V. (1999) Citrate carrier and lipogenic enzyme activities
in lead nitrate-induced pro liferative and apoptotic phase in rat liver. Biochem. Mol. Biol. Int. 47: 607-614.
Dock, L. (1989) Induction of ra t liver glutathione transferas e isoenzyme 7-7 by lead nitrate. Biol. Trace Elem. Res.

21: 283-288.

Donald, J. M.; Cutler, M. G.; Moore, M. R.; Bardley, M. (1986) Effects of lead in the laboratory mouse—2: development and social behaviour after lifelong administration of a small dose of lead acetate in drinking
fluid. Neuropharmacology 25: 151-160.

Donald, J. M.; Cutler, M. G.; Moore, M. R. (1987) Effects of lead in the labo ratory mouse. Development and social behaviour after lifelong exposure to 12 μM lead in drinking fluid. Neuropharmacology 26: 391-399.
Donaldson, W. E.; Leeming, T. K. (198 4) Dietary lead: effects on hepatic fatty acid composition in chicks. Toxicol.
Appl. Pharmacol. 73: 119-123. Donaldson, J.; Hemming, R.; LaBella, F. (1985) Vanadium exposure enhances lipid peroxidation in the kidney of
rats and mice. Can. J. Phys iol. Pharmacol. 63: 196-199.
Dorman, R. V.; Freeman, E. J. (2 002) Lead-dependent effects on arachidonic acid accumulation and the proliferation of vascular smooth muscle. J. Biochem. Mol. Toxicol. 16: 245-253.
Dorward, A.; Yagminas, A. P. (1994) Activity of erythrocyte δ -aminolevulinic acid dehydratase in the female
cynomolgus monkey ( Macaca fascicularis ): kinetic analysis in control and lead-exposed animals. Comp. Biochem. Physiol. B: Biochem. Mol. Biol. 108: 241-252.
Dowd, T. L.; Rosen, J. F.; Gupta, R. K. (1990) 31P NMR and saturation transfer studies of the effect of PB2+ on

cultured osteoblastic bone cells. J. Biol. Chem. 265: 20833-20838.
Dowd, T. L.; Rosen, J. F.; Gundberg, C. M.; Gupta, R. K. (1994) The displacement of calcium from osteocalcin at
submicromolar concentrations of free lead. Biochim. Biophys. Acta 1226: 131-137. Dowd, T. L.; Rosen, J. F.; Mints, L.; Gundberg, C. M. (2001) The effect of Pb2+ on the structure and
hydroxyapatite binding propertie s of osteocalcin. Biochim. Biophys. Acta 1535: 153-163.

Dunon, D.; Allioli, N.; Vainio , O.; Ody, C.; Imhof, B. A. (1998) Renewal of thymocyte progenitors and emigration of thymocytes during avian development. Dev. Comp. Immunol. 22: 279-287.
Dursun, N.; Arifoglu, C.; Süer, C.; Ke skinol, L. (2005) Blood pressure re lationship to nitric oxide, lipid
peroxidation, renal function, and renal blood flow in ra ts exposed to low lead levels. Biol. Trace Elem. Res.

104: 141-150.
DuVal, G.; Fowler, B. A. (1989) Pre liminary purification and characterization studies of a low molecular weight,
high affinity cytosolic lead-binding protein in rat brain. Biochem. Biophys. Res. Commun. 159: 177-184. Duydu, Y.; Süzen, H. S.; Aydin, A.; Cander, O.; Uysal, H. ; Isimer, A.; Vural, N. (2001) Correlation between lead
exposure indicators and sister chromatid exchange (SCE) frequencies in lymphocytes from inorganic lead
exposed workers. Arch. Environ. Contam. Toxicol. 41: 241-246. Dyatlov, V. A.; Lawrence, D. A. (2002) Neonatal l ead exposure potentiates sickness behavior induced by Listeria

monocytogenes infection of mice. Brain Behav. Immun. 16: 477-492.
Dyatlov, V. A.; Platoshin, A. V.; Lawrence, D. A.; Ca rpenter, D. O. (1998a) Lead potentiates cytokine- and glutamate-mediated increases in permeability of the blood-brain barrier. Neurotoxicology 19: 283-292.
Dyatlov, V. A.; Dyatlova, O. M.; Parsons, P. J.; Lawrence, D. A.; Carpenter, D. O. (1998b) Lipopolysaccharide and interleukin-6 enhance lead entry into cerebellar neuron s: application of a new and sensitive flow cytometric
technique to measure intracellular lead and calc ium concentrations. Neurotoxicology 19: 293-302.

# AX5-201 Eder, K.; Reichlmayr-Lais, A. M.; Kirchgeßner, M. (1 990) Activity of Na-K-ATPase and Ca-Mg-ATPase in red
blood cell membranes of lead-depleted rats. J. Tr ace Elem. Electrolytes Health Dis. 4: 21-24. Egle, P. M.; Shelton, K. R. (1986) Chronic lead intoxicatio n causes a brain-specific nuclear protein to accumulate in
the nuclei of cells lining kidney tubules. J. Biol. Chem. 261: 2294-2298.
Eisenmann, D. R.; Yaeger, J. A. (1969) Alterations in the formation of rat dentine and enamel induced by various

ions. Arch. Oral Biol. 14: 1045-1064.
El-Fawal, H. A. N.; Waterman, S. J.; De Feo, A.; Shamy, M. Y. (1999) Neuroimmunotoxicology: humoral
assessment of neurotoxicity and autoimmune mechan isms. Environ. Health Perspect. 107(suppl. 5):

767-775. Elias, Z.; Poirot, O.; Pezerat, H.; Suquet, H.; Schneider, O.; Daniere, M. C.; Te rzetti, F.; Baruthio, F.; Fournier, M.;
Cavelier, C. (1989) Cytotoxic and neoplastic transforming effects of industrial hexavalent chromium pigments in Syrian hamster embryo cells. Carcinogenesis 10: 2043-2052.

Elias, Z.; Poirot, O.; Baruthio, F.; Da nière, M. C. (1991) Role of solub ilized chromium in the induction of morphological transformation of Syrian hamster em bryo (SHE) cells by particulate chromium(VI)
compounds. Carcinogenesis 12: 1811-1816.
El-Missiry, M. A. (2000) Prophylactic effect of melatonin on lead-induced inhibition of heme biosynthesis and deterioration of antioxidant systems in male rats. J. Biochem. Mol. Toxicol. 14: 57-62.
Englyst, V.; Lundstrom, N. G.; Gerhardsson, L.; Rylander, L.; Nordberg, G. (2001) Lung cancer risks among lead
smelter workers also exposed to arsenic. Sci. Total Environ. 273: 77-82. Ercal, N.; Treeratphan, P.; Hammond, T. C.; Matthews, R. H.; Grannemann, N. H.; Spitz, D. R. (1996) In vivo
indices of oxidative stress in lead-exposed C57BL/6 mice are reduced by treatment with meso -2,3- dimercaptosuccinic acid or N -acetylcysteine. Free Radical Biol. Med. 21: 157-161. Eriksson, L. E. G.; Beving, H. (1993) Calcium- and lead-a ctivated morphological change s in human erythrocytes: a
spin label study of the cytoplasm. Arch. Biochem. Biophys. 303: 296-301.

Escribano, A.; Revilla, M.; Hernandez, E. R.; Seco, C.; Gonzalez-Riola, J.; Villa , L. F.; Rico, H. (1997) Effect of lead on bone development and bone mass: a morphometric, densitometric, and histomorphometric study in
growing rats. Calcif. Tiss. Int. 60: 200-203.
Ewers, U.; Stiller-Winkler, R.; Idel, H. (1982) Serum im munoglobulin, complement C3, and salivary IgA levels in

lead workers. Environ. Res. 29: 351-357.

Exon, J. H.; Koller, L. D.; Kerkvliet, N. I. (1979) Lead-cadmium interaction: effects on viral-induced mortality and

tissue residues in mice. Arch. Environ. Health 34: 469-475. Fahmy, M. A. (1999) Lead acetate genotoxicity in mice. Cytologia 64: 357-365.

Faith, R. E.; Luster, M. I.; Kimmel, C. A. (1979) Effect of chronic developm ental lead exposure on cell-mediated immune functions. Clin. Exp. Immunol. 35: 413-420.
Fanning, D. (1988) A mortality study of lead workers, 1926-1985. Arch. Environ. Health 43: 247-251.
Farant, J.-P.; Wigfield, D. C. (1987) Interaction of divalent metal ions with normal and lead-inhibited human erythrocytic porphobilinogen synthase in vitr o. Toxicol. Appl. Pharmacol. 89: 9-18.
Farant, J.-P.; Wigfield, D. C. (1990) The effects of copper, zinc, mercury, and cadmium on rabbit erythrocytic
porphobilinogen synthase in vivo. J. Anal. Toxicol. 14: 222-226. Farmand, F.; Ehdale, A.; Roberts, C. K.; Sindhu, R. K. (2005) Lead-induced dysregulation of superoxide
dismutases, catalase, glutathione peroxidase, and guanylate cyclas e. Environ. Res. 98: 33-39.

Favalli, L.; Chiari, M. C.; Piccinini, F. ; Rozza, A. (1977) Experimental inves tigations on the contraction induced by

lead in arterial smooth muscle. Acta Pharmacol. Toxicol. 41: 412-420.
Featherstone, J. D.; Goodman, P.; McLean, J. D. (1979) Electron microscope study of defect zones in dental enamel.

J. Ultrastruct. Re s. 67: 117-123. Featherstone, J. D. B.; Nelson, D. G. A.; McLean, J. D. (1981) An electron microscope study of modifications to
defect regions in dental enamel and synthetic apatites. Caries Res. 15: 278-288.
Fehlau, R.; Grygorczyk, R.; Fuhrmann, G. F.; Schwarz, W. (1989) Modulation of the Ca2+- or Pb2+-activated K+- selective channels in human red cells. II. Parallelisms to modulation of the activity of a membrane-bound

oxidoreductase. Biochim. Bi ophys. Acta 978: 37-42.

Fels, L. M.; Herbort, C. ; Pergande, M.; Jung, K.; Hotter, G.; Roselló, J.; Gelpi, E.; Mutti, A.; De Broe, M.; Stolte, H. (1994) Nephron target sites in chronic exposure to lead. Nephrol. Dial. Transplant. 9: 1740-1746.
Ferguson, S. A.; Bowman, R. E. (1990) Effects of postnatal lead exposure on open field behavior in monkeys. Neurotoxicology Teratol. 12: 91-97.
Ferguson, S. A.; Holson, R. R.; Gazzara, R. A.; Siitonen, P. H. (1998) Minimal behavioral effects from moderate
postnatal lead treatment in rats. Neurotoxicol. Teratol. 20: 637-643.

# AX5-202 Ferguson, C.; Kern, M.; Audesirk, G. (2000) Nanomolar concentrations of inorganic lead increase Ca2+ efflux and
decrease intracellular free Ca2+ ion concentrations in cultured rat hippocampal neurons by a calmodulindependent mechanism. Neurotoxicology 21: 365-378.
Ferm, V. H.; Carpenter, S. J. (1967) Developmental malformations resulting from the administration of lead salts.
Exp. Mol. Pathol. 7: 208-213.

Fernandez-Cabezudo, M. J.; Ha ssan, M. Y.; Mustafa, N.; El-Sharkawy, R. ; Fahim, M. A.; Al-Ramada, K. (2003)
Alpha tocopherol protects against immunosuppressive and immunotoxic effects of lead. Free Radical Res.

37: 437-445.

Filkins, J. P.; Buchanan, B. J. (1973) Effects of lead acetate on sensitivity to shoc k, intravascular carbon and
endotoxin clearances, and hepatic endotoxin detoxification. Proc. Soc. Exp. Biol. Med. 142: 471-475.
Fischbein, A.; Tsang, P.; Luo, J.-C. J.; Roboz, J. P.; Jiang, J. D.; Bekesi, J. G. (1993) Phenotypic aberrations of the CD3+ and CD4+ cells and functional impairments of lymphocytes at low-level occupational exposure to
lead. Clin. Immunol. Immunopathol. 66: 163-168. Flohé, S. B.; Brüggemann, J.; Herder, C.; Goebel, C.; Kolb, H. (2002) Enhanced proinflammatory response to
endotoxin after priming of m acrophages with lead ions. J. Leukoc. Biol. 71: 417-424.

Flora, G. J. S.; Seth, P. K. (1999) Beneficial effects of S -adenosyl- L 

# -methionine on aminolevulinic acid dehydratase, glutathione, and lipid peroxidation during acute lead—ethanol administration in mice. Alcohol 18: 103-108.
Flora, S. J. S.; Tandon, S. K. (1987) Influence of calcium disodium edetate on the toxic effects of lead
administration in pregnant rats. Indian J. Physiol. Pharmacol. 31: 267-272. Flora, S. J. S.; Singh, S.; Tandon, S. K. (1989) Thiamine and zinc in prevention or therapy of lead intoxication.

J. Int. Med. Res. 17: 68-75.
Flora, S. J. S.; Jeevaratnam, K.; Kumar, D. (1993) Preventive effects of sodium molybdate in lead intoxication in

rats. Ecotoxicol. Environ. Saf. 26: 133-137.
Flora, S. J. S.; Bhattacharya , R.; Sachan, S. R. S. (1994) Dose-dependent effects of zinc supplementation during

chelation of lead in rats. Ph armacol. Toxicol. 74: 330-333. Flora, S. J. S.; Bhattacharya, R.; Vijayaraghava n, R. (1995) Combined therapeutic potential of meso -2,3- dimercaptosuccinic acid and calcium disodium edetate on the mobilization and distribution of lead in
experimental lead intoxication in rats. Fundam. Appl. Toxicol. 25: 233-240.

Flora, S. J. S.; Pande, M.; Mehta, A. (2003) Beneficial effect of combin ed administration of some naturally
occurring antioxidants (vitamins) and thiol chelators in the treatment of chronic lead intoxication. Chem.

Biol. Interact. 145: 267-280.
Flora, S. J. S.; Pande, M.; Bhadauria, S.; Kannan, G. M. (2004) Combined administration of taurine and meso-2,3-
dimercaptosuccinic acid in the treat ment of chronic lead intoxication in rats. Hum. Exp. Toxicol.

23: 157-166. Fontanellas, A.; Navarro, S.; Morán-Jiménez, M.-J.; Sánchez-Fructuoso, A. I.; Vegh, I.; Barrientos, A.; De
Salamanca, R. E. (2002) Erythrocyte aminolevulinate de hydratase activity as a lead marker in patients with chronic renal failure. Am. J. Kidney Dis. 40: 43-50.
Foote, R. H. (1999) Fertility of rabb it sperm exposed in vitro to cadmium and lead. Reprod. Toxicol. 13: 443-449.
Fortoul, T. I.; Moncada-Hernández, S.; Saldivar-Osorio, L.; Espejel-Maya, G.; Mussali-Galante, P.; Del Carmen Ávila-Casando, M.; Colín-Barenque, L.; He rnández-Serrato, M. I.; Ávila-Costa, M. R. (2005)

Sex differences in brochiolar epith elium response after the inhalation of lead acetate (Pb). Toxicology

207: 323-330. Foster, W. G. (1992) Reproductive toxicity of chronic lead exposure in the female cynomolgus monkey. Reprod.

Toxicol. 6: 123-131.
Foster, W. G.; Stals, S. I.; McMahon, A. (1992) An ultrasound study of the effect of chronic lead exposure on endometrial cycle change s in the female cynomolgus monkey. J. Med. Primatol. 21: 353-356.
Foster, W. G.; McMahon, A.; YoungLai, E. V.; Hughes, E. G.; Rice, D. C. (1993) Repr oductive endocrine effects of
chronic lead exposure in the male cynomolgus monkey. Reprod. Toxicol. 7: 203-209. Foster, W. G.; McMahon, A.; Rice, D. C. (1996a) Sperm chromatin structure is altered in cynomolgus monkeys with
environmentally relevant blood lead levels. Toxicol. Ind. Health 12: 723-735.
Foster, W. G.; McMahon, A.; Rice, D. C. (1996b) Subclinical changes in luteal function in cynomolgus monkeys with moderate blood lead levels. J. Appl. Toxicol. 16: 159-163.
Foster, W. G.; Singh, A.; McMahon, A.; Rice, D. C. (1998) Chronic lead exposure effects in the cynomolgus monkey ( Macaca fascicularis ) testis. Ultrastruct. Pathol. 22: 63-71.
Fowler, B. A. (1992) Mechanisms of kidney cell injury from metals. Environ. Health Perspect. 100: 57-63.

# AX5-203 Fowler, B. A. (1998) Roles of lead-binding proteins in mediating lead bioavailability. Environ. Health Perspect.
Suppl. 106(6): 1585-1587. Fowler, B. A.; DuVal, G. (1991) Effects of lead on the kidney: roles of high-affinity lead-binding proteins. Environ.
Health Perspect. 91: 77-80.
Fowler, B. A.; Mahaffey, K. R. (1978) Interactions among lead, cadmium, and arsenic in relation to porphyrin excretion patterns. Environ. Health Perspect. 25: 87-90.

Fowler, B. A.; Kimmel, C. A.; Woods, J. S.; McConnell, E. E.; Grant, L. D. (1980) Chronic low-level lead toxicity
in the rat. III. An integrated assessment of long-term toxicity with special refere nce to the kidney. Toxicol. Appl. Pharmacol. 56: 59-77.
Fowler, B. A.; Kahng, M. W.; Smith, D. R.; Conner, E. A.; Laughlin, N. K. (1993) Implications of lead binding
proteins for risk assessment of lead exposure. J. Exposure Anal. Environ. Epidemiol. 3: 441-448. Fowler, B. A.; Whittaker, M. H.; Lipsky, M.; Wang, G. ; Chen, X.-Q. (2004) Oxidative stress induced by lead,
cadmium and arsenic mixtures: 30-day, 90-day, and 180-day drinking water studies in rats: an overview.

Biometals 17: 567-568.
Fox, D. A.; Chu, L. W.-F. (1988) Rods are selectively a ltered by lead: II. ultrastructure and quantitative histology.
Exp. Eye Res. 46: 613-625. Fox, D. A.; Farber, D. B. (1988) Rods are selectively altered by lead: I. electrophysiology and biochemistry. Exp.
Eye Res. 46: 597-611. Fox, D. A.; Rubinstein, S. D. (1989) Age-related chan ges in retinal sensitivity, rhodopsin content and rod outer segment length in hooded rats following low-level lead exposure during development. Exp. Eye Res.

48: 237-249. Fox, D. A.; Sillman, A. J. (1979) Heavy metals affect rod, but not cone, photoreceptors. Science (Washington, DC)

206: 78-80.
Fox, D. A.; Katz, L. M.; Farber, D. B. (1991a) Low le vel developmental lead exposure decreases the sensitivity,
amplitude and temporal resolution of rods. Neurotoxicology 12: 641-654. Fox, D. A.; Rubinstein, S. D.; Hsu, P. (1991b) Developmenta l lead exposure inhibits adult rat retinal, but not kidney,
Na+,K+-ATPase. Toxicol. Appl. Pharmacol. 109: 482-493.
Fox, D. A.; Srivastava, D.; Hurwitz, R. L. (1994) Lead-induced alterations in rod-mediated visual functions and cGMP metabolism: new insights. Neurotoxicology 15: 503-512.
Fox, D. A.; Campbell, M. L.; Blocker, Y. S. (1997) Fu nctional alterations and apoptotic cell death in the retina
following developmental or adult lead exposure. Neurotoxicology 18: 645-664.

Fracasso, M. E.; Perbe llini, L.; Solda, S.; Talamini, G. ; Franceschetti, P. (2 002) Lead induced DNA strand breaks in
lymphocytes of exposed workers: role of reactive oxygen species and protein kinase C. Mutat. Res.

515: 159-169. Franklin, C. A.; Inskip, M. J.; Baccanal e, C. L.; Edwards, C. M.; Manton, W. I.; Edwards, E.; O'Flaherty, E. J.
(1997) Use of sequentially administer ed stable lead isotopes to investigate changes in blood lead during pregnancy in a nonhuman primate ( Macaca fascicularis ). Fundam. Appl. Toxicol. 39: 109-119.
Franks, P. A.; Laughlin, N. K.; Dierschk e, D. J.; Bowman, R. E.; Meller, P. A. (1989) Effects of lead on luteal
function in rhesus monkeys. Biol. Reprod. 41: 1055-1062. Fu, H.; Boffetta, P. (1995) Cancer and occupational exposure to inorganic lead compounds: a meta-analysis of
published data. Occup. Environ. Med. 52: 73-81.
Fuentes, M.; Torregrosa, A.; Mo ra, R.; Götzens, V.; Corbella, J.; Domingo, J. L. (1996) Placental effects of lead in

mice. Placenta 17: 371-376.
Fujita, H.; Orii, Y.; Sano, S. (1981) Evidence of increased synthesis of δ -aminolevulinic acid dehydratase in
experimental lead-poisoned rats. Biochim. Biophys. Acta 678: 39-50. Fujita, H.; Sato, K,; Sano, S. (1982) Increase in the amount of Erythrocyte δ -aminolevulinic acid dehydratase in
workers with moderate lead exposure. Int. Arch. Occup. Environ. Health 50: 287-297.
Fujiwara, Y.; Kaji, T. (1999) Possible mechanism for lead inhibition of vascular endothelial cell proliferation: a lower response to basic fibroblast growth factor through inhibition of heparan sulfate synthesis. Toxicology

133: 147-157. Fujiwara, Y.; Kaji, T.; Yamamoto, C.; Sakamoto, M.; Ko zuka, H. (1995) Stimulatory effect of lead on the proliferation of cultured vascular smooth-muscle cells. Toxicology 98: 105-110.
Fujiwara, Y.; Watanabe, S.; Sakamoto, M.; Kaji, T. (1998) Repair of wounded monolayers of cultured vascular endothelial cells after simultaneous exposure to lead and zinc. Toxicol. Lett. 94: 181-188.
Fukumoto, K.; Karai, I.; Horiguchi, S. (1983) Effect of lead on erythrocyte membranes. Br. J. Ind. Med.

40: 220-223.

# AX5-204 Fullmer, C. S. (1991) Intestin al calcium and lead absorpti on: effects of dietary lead and calcium. Environ. Res.

54: 159-169. Fullmer, C. S. (1992) Intestinal interactions of lead and calcium. Neurotoxicology 13: 799-807.
Fullmer, C. S. (1995) Dietary calcium levels and treatment interval determin e the effects of lead ingestion on plasma
1,25-dihydroxyvitamin D concentration in chicks. J. Nutr. 125: 1328-1333.
Fullmer, C. S. (1997) Lead—calcium interactions: invo lvement of 1,25-dihydroxyvitamin D. Environ. Res.

72: 45-55.
Fullmer, C. S.; Rosen, J. F. (1990) E ffect of dietary calcium and lead stat us on intestinal calcium absorption.

Environ. Res. 51: 91-99.

Fullmer, C. S.; Edelstein, S.; Wasserm an, R. H. (1985) Lead-binding properties of intestinal calcium-binding
proteins. J. Biol. Chem. 260: 6816-6819.

Fullmer, C. S.; Chandra, S.; Smith, C. A.; Morrison, G. H.; Wasserman, R. H. (1996) Ion microscopic imaging of
calcium during 1,25-dihydroxyvitamin D-mediated intestinal absorption. Histochem. Cell Biol.

106: 215-222. Furono, K.; Suetsugu, T.; Sugihara, N. (1996) Effects of metal ions on lipid peroxidation in cultured rat hepatocytes

loaded with α -linolenic acid. J. Toxicol. Environ. Health 48: 121-129. Gainer, J. H. (1977) Effects of heavy metals and of defici ency of zinc on mortality rates in mice infected with
encephalomyocarditis virus. Am. J. Vet. Res. 38: 869-872.
Gallagher, K.; Matarazzo, W. J.; Gray, I. (1979) Trace me tal modification of immunocom petence. II. Effect of Pb2+, Cd2+, and Cr3+ on RNA turnover, hexokinase activity, and blastogenesis during B-lymphocyte

transformation in vitro . Clin. Immunol. Immunopathol. 13: 369-377.
Gandley, R.; Anderson, L.; Silbergeld, E. K. (1999) Lead: male-mediated e ffects on reproduction and development

in the rat. Environ. Res. A 89: 355-363.
Garavan, H.; Morgan, R. E.; Levitsky, D. A.; Hermer-Vaz quez, L.; Strupp, B. J. (2000) Enduring effects of early
lead exposure: evidence for a specific deficit in associative ability. Neurotoxicol. Teratol. 22: 151-164. Garcia, T. A.; Corredor, L. (2004) Biochemical changes in the kidneys after perinatal intoxication with lead and/or
cadmium and their antagonistic effects when coadmi nistered. Ecotoxicol. Environ. Saf. 57: 184-189.
Gautam, A. K.; Chowdhury, A. R. (1987) Effect of lead on erythropoietic system of intact and splenectomized rats. Indian J. Physiol. Pharmacol. 31: 117-124.
Gaworski, C. L.; Sharma, R. P. (1978) The effects of heavy metals on [3H]thymidine uptake in lymphocytes.
Toxicol. Appl. Pharmacol. 46: 305-313. Gerhardsson, L.; Brune, D.; Nordberg, G. F.; Wester, P. O. (1986) Distribution of cadmium, lead and zinc in lung,
liver and kidney in long-term exposed smelter workers. Sci. Total Environ. 50: 65-85. Gerhardsson, L.; Hagmar, L.; Rylander, L.; Skerfving, S. (1995) Mortality and cancer incidence among secondary
lead smelter workers. Occup. Environ. Med. 52: 667-672.
Gerlach, R. F.; Souza, A. P.; Cury, J. A.; Line, S. R. P. (2000a) Effect of lead, cadmium and zinc on the activity of enamel matrix proteinases in vitro . Eur. J. Oral Sci. 108: 327-334.

Gerlach, R. F.; Toledo, D. B.; Novaes, P. D.; Merzel, J.; Li ne, S. R. P. (2000b) The effect of lead on the eruption

rates of incisor teeth in rats. Arch. Oral Biol. 45: 951-955. Gerlach, R. F.; Cury, J. A.; Krug, F. J.; Line, S. R. P. (2002) Effect of lead on dental enamel formation. Toxicology

175: 27-34.

Gewirtz, A. T.; Liu, Y.; Sitaraman, S. V.; Madara, J. L. (2002) Intestinal epithelial pathobiology: past, present and

future. Best Pract. Res. Clin. Gastroenterol. 16: 851-867.
Giavini, E.; Prati, M.; Vismara, C. ( 1980) Effects of cadmium, lead and copper on rat preimplantation embryos.

Bull. Environ. Contam. Toxicol. 25: 702-705. Gibson, S. L. M.; Goldberg, A. (1970) Defects in haem synthesis in mammalian tissues in experimental lead
poisoning and experimental porphyria. Clin. Sci. 38: 63-72.

Gilbert, M. E.; Mack, C. M. (1998) Chronic lead exposure accelerates de cay of long-term poten tiation in rat dentate gyrus in vivo. Brain Res. 789: 139-149.
Gilbert, S. G.; Rice, D. C. (1987) Low-level lifetime lead exposure produces behavioral toxicity (spatial
discrimination reversal) in adult monkeys. Toxicol. Appl. Pharmacol. 91: 484-490. Gilbert, M. E.; Mack, C. M.; Lasley, S. M. (1996) Chroni c developmental lead exposure increases the threshold for
long-term potentiation in rat dentate gyrus in vivo. Brain Res. 736: 118-124.Gilbert, M. E.; Mack, C. M.; Lasley, S. M. (1999a) The influence of developmental period of lead exposure on longterm potentiation in the adult rat dentate gyrus in vivo . Neurotoxicology 20: 57-69.

# AX5-205Gilbert, M. E.; Mack, C. M.; Lasley, S. M. (1999b) Chronic developmental lead exposure and hippocampal longterm potentiation: biphasic dose-response relationship. Neurotoxicology 20: 71-82. Gilbert, M. E.; Kelly, M. E.; Samsam, T. E.; Goodman, J. H. (2005) Chronic developmental lead exposure reduces
neurogenesis in adult rat hippocampus but does not impair spatial learning. Toxicol. Sci. 86:
Giridhar, J.; Isom, G. E. (1990) Interaction of lead acetate with atrial natriu retic factor in rats. Life Sci. 46: 569-576. Göbel, T. W. F. (1996) The T-dependent immune system. In: Davidson, T. F.; Morris, T. R.; Payne, L. N., eds.
Poultry immunology. Abingdon, Oxfordshire, England: Carfax Publishing Co.; pp. 83-114. (Poultry science
symposium series, no. 24).

Goebel, C.; Kirchhoff, K.; Wasmuth, H.; Flohé, S. B.; Ellio tt, R. B.; Kolb, H. (1999) The gut cytokine balance as a
target of lead toxicity. Life Sci. 64: 2207-2214.

Goebel, C.; Flohé, S. B.; Kirchhoff, K.; Herder, C.; Kolb, H. (2000) Orally admi nistered lead chloride induces bias of mucosal immunity. Cytokine 12: 1414-1418.
Goering, P. L.; Fowler, B. A. (1984) Regulation of lead inhibition of δ -aminolevulinic acid dehydratase by a low molecular weight, high affinity renal lead-binding protein. J. Pharmacol. Exp. Ther. 231: 66-71.
Goering, P. L.; Fowler, B. A. (1985) Mechanism of renal lead-binding protein reversal of δ -aminolevulinic acid
dehydratase inhibition by lead. J. Pharmacol. Exp. Ther. 234: 365-371. Goering, P. L.; Fowler, B. A. (1987a) Regulatory roles of high-affinity metal-binding proteins in mediating lead

effects on δ -aminolevulinic acid dehydratase. Ann. N. Y. Acad. Sci. 514: 235-247.
Goering, P. L.; Fowler, B. A. (1987b) Kidney zinc-thionein regulation of δ -aminolevulinic acid dehydratase inhibition by lead. Arch. Bichem. Biophys. 253: 48-55.
Goering, P. L.; Mistry, P.; Fowler, B. A. (1986) A low molecular weight lead-binding protein in brain attenuates

lead inhibition of δ -aminolevulinic acid dehydratase: comparison with a renal lead-binding protein. J. Pharmacol. Exp. Ther. 237: 220-225.
Goldstein, G. W. (1993) Evidence that lead acts as a calcium substitute in second messenger metabolism.
Neurotoxicology 14(2-3): 97-101. Golubovich, E. Ya.; Avkhimenko, M. M.; Chirkova, E. M. (1968) Biochemical and morphological changes in the
testicles of rats induced by small doses of lead. Toksikol. Nov. Prom. Khim. Veschestv. 10: 63-73.
Gong, Z.; Evans, H. L. (1997) Effect of chelation with meso -dimercaptosuccinic acid (DMS A) before and after the appearance of lead-induced neurotoxicity in the rat. Toxicol. Appl. Pharmacol. 144: 205-214.
Gonick, H. C.; Khalil-Manesh, F.; Raghavan, S. R. V. ( 1985) Characterization of human erythrocyte lead-binding
protein. In: Lekkas, T. D., ed. International conference: heavy metals in the environment; September; Athens, Greece, v. 1. Edinburgh, United Kingdom: CEP Consultants, Ltd.; pp. 313-316.
Gonick, H. C.; Ding, Y.; Bondy, S. C.; Ni, Z.; Vaziri, N. D. (1997) Lead-induced hypertension: interplay of nitric oxide and reactive oxygen species. Hypertension 30: 1487-1492.
Gonick, H. C.; Ding, Y.; Vaziri, N. D. (1998) Effect of low lead exposure on eicosanoid excretion in rats.
Prostaglandins Other Lipid Mediators 55: 77-82.

González-Riola, J.; Hernández, E. R.; Es cribano, A.; Revilla, M.; Villa, C.-S. L. F.; Rico, H. (1997) Effect of lead
on bone and cartilage in sexually mature rats: a mo rphometric and histomorphometry study. Environ. Res.

74: 91-93. Gorbel, F.; Boujelbene, M.; Makni-Ayadi, F.; Guermazi, F.; Croute, F.; Soleilhavoup, J. P.; El Feki, A. (2002)
Exploration des effets cytotoxiques du plomb sur la fonction sexuelle endocrine et exocrine chez le rat
pubère mâle et femelle. Mise en évidence d'une action apoptotique [Impact of lead given in drinking water on the endocrine and exocrine sexual activity in pubescent rats. Determination of an apoptotic process].

C. R. Biol. 325: 927-940.

Govoni, S.; Lucchi, L.; Battaini, F.; Spano, P. F.; Trabucchi, M. (1984) Chronic lead treatment affects dopaminergic control of prolactin secretion in rat pituitary. Toxicol. Lett. 20: 237-241.
Goyer, R. A. (1968) The renal tubule in lead poisoning. I. Mitochondrial swelling and aminoaciduria. Lab. Invest.

19: 71-77. Goyer, R. A.; Rhyne, B. C. (1973) Pathological e ffects of lead. Int. Rev. Exp. Pathol. 12: 1-77.
Goyer, R. A.; Wilson, M. H. (1975) Lead-induced inclusion bodies: results of ethylenediaminetetraacetic acid

treatment. Lab. Invest. 32: 149-156. Goyer, R. A.; Krall, A.; Kimball, J. P. (1968) The renal tubule in lead poisoning. II. In vitro studies of mitochondrial

structure and function. Lab. Invest. 19: 78-83. Goyer, R. A.; Leonard, D. L.; Bream, P. R.; Irons, T. G. (1970a) Aminoaciduria in experimental lead poisoning.
Proc. Soc. Exp. Biol. Med. 135: 767-771.

# AX5-206 Goyer, R. A.; Leonard, D. L.; Moore, J. F.; Rhyne, B. Krigman, M. R. (1970b) Lead dosage and the role of the
intranuclear inclusion body: an experimental study. Arch. Environ. Health 20: 705-711.
Goyer, R. A.; May, P.; Cates, M. M.; Krigman, M. R. (1970c) Lead and prot ein content of isolated intranuclear
inclusion bodies from kidneys of lead-poisoned rats. Lab. Invest. 22: 245-251.
Goyer, R. A.; Cherian, M. G.; Delaquerriere-Richardson, L. (1978) Renal effects of repeated administration of calcium disodium ethylenediamnetetraacet ate during excessive exposure to l ead in rats. J. Environ. Pathol.

Toxicol. 1: 403-410.
Grabowska, M.; Guminska, M. (1996) Th e effect of lead on lactate forma tion, ATP level and membrane ATPase activities in human erythrocytes in vitro. Int. J. Occup. Med. Environ. Health 9: 265-274.
Graca, A.; Ramalho-Santos, J.; De Lourdes Pereira, M. (2004) Effect of lead chloride on spermatogenesis and sperm
parameters in mice. Asian J. Androl. 6: 237-241.

Granick, J. L.; Sassa, S.; Granick, S. ; Levere, R. D.; Kappas, A. (1973) St udies in lead poisoning. II. correlation

between the ratio of activated to inactivated δ -aminolevulinic acid dehydratase of whole blood and the blood

lead level. Biochem. Med. 8: 149-159.

Grant, L. D.; Kimmel, C. A.; West, G. L.; Martinez-Vargas, C. M.; Howard, J. L. (1980) Chronic low-level lead
toxicity in the rat. II. Effects on postnatal physical and behavioral development. Toxicol. Appl. Pharmacol.

56: 42-58.

Grobler, S. R.; Rossouw, R. J.; Kotze, D. (1985) Lead in teeth of weanling ra ts received via the maternal drinking

water. Arch. Oral Biol. 30: 509-511.

Grobler, S. R.; Rossouw, R. J.; Kotze, T. J. V.; Stander, I. A. (1991) The effect of airbor ne lead on lead levels of

blood, incisors and alveolar bone of rats. Arch. Oral Biol. 36: 357-360.

Grover, C. A.; Nation, J. R.; Brattom. G. R. (1993) Chronic exposu re to lead attenuates co caine-induced behavioral

activation. Pharmacol. Biochem. Behav. 44: 221-225.

Gruber, H. E.; Gonick, H. C.; Khalil-Manesh, F.; Sanchez, T. V.; Motsinger, S.; Meyer, M.; Sharp, C. F. (1997)
Osteopenia induced by long-term, low- and high-level e xposure of the adult rat to lead. Miner. Electrolyte

Metab. 23: 65-73.
Guilarte T. R.; McGlothan, J. L. (1998) Hippocampal NMDA receptor mRNA undergo es subunit specific changes
during developmental lead exposure. Brain Res. 790: 98-107. Guilarte T. R.; McGlothan, J. L. (2003) Selective decrease in NR1 subunit splice variant mRNA in the hippocampus
of Pb2+-exposed rats: implications for synaptic targeting and cell surface expression of NMDAR
complexes. Mol. Brain Res. 113: 37-43.
Guilarte, T. R.; Miceli, R. C. (1992) Age-dependent effects of lead on [3H] MK-801 binding to the NMDA receptorgated ionophore: in vitro and in vivo studies. Neurosci. Lett. 148: 27-30. Guilarte, T. R.; McGlothan, J. L.; Nihei, M. K. (2000) Hippocampal expression of N -methyl- D 

# -aspartate receptor (NMDAR1) subunit splice variant mRNA is altered by developmental exposure to Pb2+. Mol. Brain Res.

76: 299-305.
Guilarte, T. R.; Toscano, C. D.; McGlothan, J. L.; Weaver, S. A. (2003) Environmental enrichment reverses
cognitive and molecular deficits induced by developmental lead exposure. Ann. Neurol. 53: 50-56.
Guity, P.; McCabe, M. J.; Pitts, D. K.; Santini, R. P.; P ounds, J. G. (2002) Protein kinase C does not mediate the inhibitory action of lead on vitamin D 3 

# -dependent production of osteocalcin in osteoblastic bone cells.
Toxicol. Appl. Pharmacol. 178: 109-116.
Guo, T. L.; Mudzinski, S. P.; Lawrence, D. A. (1996) The heavy metal lead modulates the expression of both TNF- α
and TNF- α receptors in lipopolysaccharide- activated human peripheral blood mononuclear cells. J. Leukoc.

Biol. 59: 932-939.
Gupta, K.; Upreti, R. K.; Kidwai, A. M. (1994) Toxico kinetic study of rat intestinal brush border membrane enzymes following in vitro exposure to lead and vanadium. Bull. Environ. Contam. Toxicol. 52: 919-926.
Gupta, P.; Husain, M. M.; Shankar, R.; Seth, P. K.; Ma heshwari, R. K. (2002) Lead exposure enhances virus
multiplication and pathogenesis in mice. Vet. Hum. Toxicol. 44: 205-210. Gurer, H.; Ercal, N. (2000) Can antioxidants be beneficial in the treatment of lead poisoning? Free Rad. Biol. Med.

29: 927-945. Gurer, H.; Neal, R.; Yang, P.; Oztezcan, S.; Ercal, N. (1999) Captopr il as an antioxidant in lead-exposed Fischer 344 rats. Hum. Exp. Toxicol. 18: 27-32. Gürer, H.; Özgünes, H.; Saygin, E.; Ercal, N. (2001) Antioxidant effect of taurine against lead-induced oxidative

stress. Arch. Environ. Contam. Toxicol. 41: 397-402.
Gutowski, M.; Altmann, L.; Sveinsson, K.; Wiegand, H. (1997) Postnatal development of synaptic plasticity in the
CA3 hippocampal region of control and lead-exposed Wistar rats. Dev. Brain Res. 98: 82-90.

# AX5-207 Gutowski, M.; Altmann, L.; Sveinsson, K.; Wiegand, H. (1998) Synaptic plasticity in the CA1 and CA3
hippocampal region of pre- and postnatally lead-exposed rats. Toxicol. Lett. 95: 195-203.

Habermann, E.; Crowell, K.; Janicki, P. (1983) Lead and other metals can substitute for Ca2+ in calmodulin. Arch.

Toxicol. 54: 61-70.

Ha ć , E.; Krechniak, J. (1996) Lead levels in bone and hair of rats treated w ith lead acetate. Biol. Trace Elem. Res.

52: 293-301. Hacker, H.-J.; Bannasch, P.; Columbano, A. (1990) Effect of lead nitrate on liver carbohydrate enzymes and
glycogen content in the rat. Carcinogenesis 11: 2199-2204.

Haider, S.; Shameem, S.; Ahmed, S. P.; Perveen, T.; Haleem, D. J. (2005) Repeated admi nistration of lead decreases
brain 5-HT metabolism and produces memory deficits in rats. Cell. Mol. Biol. Lett. 10: 669-676.
Hamilton, J. D.; O'Flaherty, E. J. (1994) Effects of lead exposure on skeletal development in rats. Fundam. Appl.

Toxicol. 22: 594-604.
Hamilton, J. D.; O'Flaherty, E. J. (1995) Influence of lead on mineralization during bone growth. Fundam. Appl.

Toxicol. 26: 265-271.
Hamilton, J. D.; O'Flaherty, E. J.; Ross, R.; Shukla, R.; Gartside, P. S. (1994) Structural equation modeling and
nested ANOVA: effects of lead exposure on maternal and fetal growth in rats. Environ. Res. 64: 53-64. Hammond, P. B.; Minnema, D. J.; Shulka, R. (1990) Lead exposure lowers the set point for food consumption and
growth in weanling rats. Toxicol. Appl. Pharmacol. 106: 80-87.
Hammond, P. B.; Minnema, D. J.; Succop, P. A. (1993) Reve rsibility of lead-induced depr ession of growth. Toxicol. Appl. Pharmacol. 123: 9-15.
Han, S.; Qiao, X.; Simpson, S.; Ameri, P.; Kemp, F. W.; Bogden, J. D. (1996) Weight loss alters organ
concentrations and contents of lead and some essential divalent metals in rats previously exposed to lead.

J. Nutr. 126: 317-323. Han, S.; Qiao, X.; Kemp, F. W.; Bogden, J. D. (1997) Lead exposure at an early age substantially increases lead
retention in the rat. Environ. Health Perspect. 105: 412-417. Han, S.; Li, W.; Jamil, U.; Dargan, K. ; Orefice, M.; Kemp, F. W.; Bogden, J. D. (1999) Effects of weight loss and

exercise on the distribution of lead and essential trace elements in rats with prior lead exposure. Environ.
Health Perspect. 107: 657-662.

Han, S.; Pfizenmaier, D. H.; Garcia, E. ; Eguez, M. L.; Ling, M.; Kemp, F. W.; Bogden, J. D. (2000) Effects of lead
exposure before pregnancy and dietary calcium during pregnancy on fetal development and lead

accumulation. Environ. Health Perspect. 108: 527-531. Haneef, S. S.; Swarup, D.; Kalicharan; Dwivedi, S. K. (1995) The effect of concurrent lead and cadmium exposure
on the cell-mediated immune response in goats. Vet. Hum. Toxicol. 37: 428-429. Hanna, L. A.; Peters, J. M.; Wiley, L. M.; Clegg, M. S. ; Keen, C. L. (1997) Comparat ive effects of essential and
non-essential metals on preimplantation mouse embryo development in vitro. Toxicology 116: 123-131.
Harry, G. J.; Schmitt, T. J. ; Gong, A.; Brown, H.; Zawia, N.; Evans, H. L. (1996) Lead-induced alterations of glial fibrillary acidic protein (GFAP) in the developing rat brain. Toxicol. Appl. Pharmacol. 139: 84-93.
Hartwig, A.; Schlepegrell, R.; Beyersmann, D. (1990) Indi rect mechanism of lead-indu ced genotoxicity in cultured

mammalian cells. Mutat. Res. 241: 75-82.

Hashmi, N. S.; Kachru, D. N.; Khandelwal, S.; Tandon, S. K. (1989) Interrelationship between iron deficiency and
lead intoxication (part 2). Biol . Trace Elem. Res. 22: 299-307.
Hayashi, M. (1983a) Lead toxicity in the pregnant rat. I. the effect of high - level lead on δ -aminolevulinic acid dehydratase activity in maternal and fetal blood or tissues. Environ. Res. 30: 152-160.
Hayashi, M. (1983b) Lead toxicity in the pregnant rat. II. Effects of low-level lead on delta-aminolevulinic acid
dehydratase activity in maternal and fetal blood or tissue. Ind. Health 21: 127-135.

He, L.; Poblenz, A. T.; Medrano, C. J.; Fox, D. A. (2000) Lead and calcium produce rod photoreceptor cell
apoptosis by opening the mitrochondrial permeability tr ansition pore. J. Biol. Chem. 275: 12175-12184.

He, L.; Perkins, G. A.; Poblenz, A. T.; Harris, J. B.; Hung, M.; Ellisman, M. H.; Fox, D. A.. (2003) Bcl-xL overexpression blocks bax-mediated mitochondrial contact site formation and apoptosis in rod
photoreceptors of lead-exposed mice. Proc. Natl. Acad. Sci. U. S. A. 100: 1022-1027.

Heiman, A. S.; Tonner, L. E. (1995) The acute effect of lead acetate on glucocorticoid regul ation of tyrosine aminotransferase in hepatoma cells. Toxicology 100: 57-68.
Hellström-Lindahl, E.; Oskarsson, A. (1990) Cellular response after mobilization of metals by diethyldithiocarbamate in rat hepatocyte cultures. Toxicology 65: 23-32.
Hemphill, F. E.; Kaeberle, M. L. ; Buck, W. B. (1971) Lead suppression of mouse resistance to Salmonella
typhimurium . Science (Washington, DC) 172: 1031-1032.

# AX5-208 Hengstler, J. G.; Bolm-Audorff, U.; Faldum, A.; Janssen, K.; Reifenrath, M.; Gotte, W.; Jung, D.; Mayer-Popken, O.; Fuchs, J.; Gebhard, S.; Bienfait, H. G.; Schlink, K.; Dietrich, C.; Faust, D.; Epe, B.; Oesch, F. (2003) Occupational exposure to heavy metals: DNA damage induction and DNA repair
inhibition prove co-exposures to cadmium, cobalt and lead as more dangerous than hitherto expected.
Carcinogenesis 24: 63-73. Henning, S. J.; Cooper, L. C. (1988) Intestinal accumulation of lead salts an d milk lead by suckling rats (42645).
Proc. Soc. Exp. Biol. Med. 187: 110-116.
Heo, Y.; Parsons, P. J.; Lawrence, D. A. (1996) Lead differentially modifies cytokine production in vitro and

in vivo . Toxicol. Appl. Pharmacol. 138: 149-157.
Heo, Y.; Lee, W. T.; Lawrence, D. A. (1997) In vivo the environmental pollutants lead and mercury induce
oligoclonal T cell responses skewed toward type-2 reactivities. Cell. I mmunol. 179: 185-195.

Heo, Y.; Lee, W. T.; Lawren ce, D. A. (1998) Differential effects of lead and cAMP on development and activities of
Th1- and Th2-lymphocytes. Toxicol. Sci. 43: 172-185.
Heo, Y.; Lee, B.-K.; Ahn, K.-D.; Lawrence, D. A. (2004) Serum IgE elevation correlates with blood lead levels in
battery manufacturing workers. Hum. Exp. Toxicol. 23: 209-213.
Herak-Kramberger, C. M.; Sabolic, I. (2001) The integrity of renal cortical brush-border and basolateral membrane vesicles is damaged in vitro by nephrotoxic heavy metals. Toxicology 156: 139-147.

Hermes-Lima, M.; Pereira, B.; Bechara, E. J. H. (1991) Are free radicals involved in lead poisoning? Xenobiotica

21: 1085-1090. Hicks, D. G.; O'Keefe, R. J.; Reynolds , K. J.; Cory-Slechta, D. A.; Puzas, J. E.; Judkins, A.; Rosier, R. N. (1996)
Effects of lead on growth plate chondrocyte phenotype. Toxicol. Appl. Pharmacol. 140: 164-172.

Hilbertz, U.; Krämer, U.; De Ruiter, N. ; Baginski, B. (1986) Effects of cadmium and lead on oxidative metabolism and phagocytosis by mouse peritoneal macrophages. Toxicology 39: 47-57.

Hilderbrand, D. C.; Der, R.; Griffin, W. T.; Fahim, M. S. (1973) Effect of lead acetate on reproduction. Am.
J. Obstet. Gynecol. 115: 1058-1065. Hilson, J. A.; Strupp, B. J. (1997) Analyses of response patterns clarify lead effects in olfactory reversal and
extradimensional shift tasks: assessment of inhibitory control, associative ability, and memory. Behav.

Neurosci. 111: 532-542. Hinton, D. E.; Lipsky, M. M.; Heatfield, B. M.; Trump, B. F. (1979) Opposite eff ects of lead on chemical
carcinogenesis in kidney and liver of rats. Bull. Environ. Contam. Toxicol. 23: 464-469.
Hogan, K.; Marcus, A.; Smith, R.; White, P. (1998) Inte grated exposure uptake biokinetic model for lead in children: empirical comparisons w ith epidemiologic data. Environ. Health Perspect. 106(suppl. 6):

1557-1567. Holgate, S.; Casale, T.; Webzek, S.; Bousquet, J.; Deniz, Y.; Reisner, C. (2005) The anti-inflammatory effects of
omalizumab confirm the central role of IgE in allergic inflammation. J. Allergy Clin. Immunol.

115: 459-465. Holladay, S. D. (1999) Prenatal immunotoxicant exposure and postnatal autoimmune disease. Environ. Health
Perspect. Suppl. 107(5): 687-691.
Holloway, W. R., Jr.; Thor, D. H. (1987) Low level lead exposure during lactation increases rough and tumble play fighting of juvenile rats. Neurotoxicol. Teratol. 9: 51-57.
Holmes, A. L.; Wise, S. S.; Xie, H.; Gordon, N.; Thomps on, D.; Wise, J. P., Sr. (2005) Lead ions do not cause
human lung cells to escape chromate-induced cytotoxicity. Toxicol. Appl. Pharmacol. 203: 167-176. Holsapple, M. P.; West, L. J.; Landreth, K. S. (2003) Species comparison of anatomical and functional immune
system development. Birth Defects Res. B. 68: 321-334.
Honchel, R.; Marsano, L.; Cohen, D.; Shedlofsky, S.; McCl ain, C. J. (1991) Lead enhances lipopolysaccharide and tumor necrosis factor liver injury. J. Lab. Clin. Med. 117: 202-208.
Horiguchi, S.; Kiyoya, I.; Endo, G.; Teramoto, K.; Shinagaw a, K.; Wakitani, F.; Konishi, Y.; Kiyota, A.; Ota, A.;
Tanaka, H.; Wang, C.; Fukui, M. (1992) Serum immunoglobulins and complement C 3 

# levels in workers exposed to lead. Osaka City Med. J. 38: 149-153.

Hotter, G.; Fels, L. M.; Closa, D.; Roselló, J.; Stolte, H.; Gelpí, E. (1995) Altered levels of urinary prostanoids in
lead-exposed workers. Toxicol. Lett. 77: 309-312. Hryhorczuk, D. O.; Rabinowitz, M. B.; He ssl, S. M.; Hoffman, D.; Hogan, M. M.; Mallin, K.; Finch, H.; Orris, P.;
Berman, E. (1985) Elimination kinetics of blood lead in workers with chronic lead intoxication. Am. J. Ind.

Med. 8: 33-42.

Hsu, P. C.; Liu, M. Y.; Hsu, C. C. ; Chen, L. Y.; Guo, Y. L. (1997) Lead exposure causes generation of reactive
oxygen species and functional impairment in rat sperm. Toxicology 26: 122: 133-143.

# AX5-209 Hsu, P. C.; Hsu, C. C.; Liu, M. Y.; Chen, L. Y.; Guo, Y. L. (1998a) Lead-induced changes in spermatozoa function

and metabolism. J. Toxicol. Environ. Health A 55: 45-64.

Hsu, P. C.; Liu, M. Y.; Hsu, C. C.; Chen, L. Y.; Guo, Y. L. (1998b) Effects of vitamin E and/or C on reactive
oxygen species-related lead toxicity in the rat sperm. Toxicology 128: 169-179.
Hu, H. (1991) A 50-year follow-up of childhood plumbism: hypertension, renal function, and hemoglobin levels among survivors. Am. J. Dis. Child. 145: 681-687.
Huang, F., Schneider, J. S. (2004) Effects of lead exposure on proliferation and differentiation of neural stem cells
derived from different regions of embryonic rat brain. Neurotoxicology.25: 1001-1012. Huang, X. P.; Feng, Z. Y.; Zhai, W. L.; Xu, J. H. (1988 ) Chromosomal aberrations and sister chromatid exchanges
in workers exposed to lead. Biomed. Environ. Sci. 1: 382-387.
Huang, B. M.; Lai, H. Y.; Liu, M. Y. (2002) Concentration dependency in lead-inhibited steroidogenesis in MA-10 mouse Leydig tumor cells. J. Toxicol. Environ. Health A 65: 557-567.
Hubermont, G.; Buchet, J.-P.; Roels, H.; Lauwerys, R. (1976) Effect of short-term administration of lead to pregnant rats. Toxicology 5: 379-384.
Hudson, C. A.; Cao, L.; Kasten-Jolly, J.; Kirkwood, J. N.; Lawrence, D. A. (2003) Susceptibility of lupus-prone
NZM mouse strains to lead exacerbation of systemic l upus erythematosus symptoms. J. Toxicol. Environ.

Health A 66: 895-918.
Hussain, I.; Piepenbrink, M. S.; Diet ert, R. R. (2005) Impact of in ovo-administered lead and testosterone on
developing female thymocytes. J. Toxicol. Environ. Health Part A. 68: 1309-1319. Hwang, K.-Y.; Lee, B.-K.; Bressler, J. P.; Bolla, K. I.; Stewart, W. F.; Schwartz, B. S. (2002) Protein kinase
C activity and the relations between blood lead and neurobehavioral function in lead workers. Environ.
Health Perspect. 110: 133-138.Hwua, Y. S.; Yang J. L. (1998) Effect of 3-aminotriazole on anchorage independence and mutagenicity in cadmiumand lead-treated diploid human fibroblasts. Carcinogenesis 19: 881-888.
Iavicoli, I.; Sgambato, A.; Carelli, G.; Ardito, R.; Cittadini, A.; Castellino, N. (2001) Lead-related effects on rat

fibroblasts. Mol. Cell. Biochem. 222: 35-40.

Iavicoli, I.; Carelli, G.; Stanek, E. J., III; Castellino, N.; Ca labrese, E. J. (2003) Effects of low doses of dietary lead
on red blood cell production in male and female mice. Toxicol. Lett. 137: 193-199.

Iavicoli, I.; Carelli, G.; Stanek, E. J., III; Castellino, N.; Ca labrese, E. J. (2004) Effects of low doses of dietary lead
on puberty onset in female mice. Reprod. Toxicol. 19: 35-41.
Ichiba, M.; Tomokuni, K. (1987) Urinary excretion of 5-hydroxyindoleacetic acid, δ -aminolevulinic acid and coproporphyrin isomers in rats and men exposed to lead. Toxicol. Lett. 38: 91-96.

Ikebuchi, H.; Teshima, R.; Suzuki, K.; Terao, T.; Yamane, Y. (1986) Simultaneous induction of Pb-metallothioneinlike protein and Zn-thionein in th e liver of rats given lead acetat e. Biochem. J. 233: 541-546. Inskip, M. J.; Franklin, C. A.; Baccanale, C. L.; Manton, W. I.; O' Flaherty, E. J.; Edwards, C. M. H.;
Blenkinsop, J. B.; Edwards, E. B. (1996) Measurement of the flux of lead from bone to blood in a nonhuman primate ( Macaca fascicularis ) by sequential administration of stable lead isotopes. Fundam.
Appl. Toxicol. 33: 235-245.
Ishihara, K.; Alkondon, M.; Montes, J. G.; Albuquerque, E. X. (1995) Nicotinic responses in acutely dissociated rat hippocampal neurons and the selective blockade of fast-desensitizing nicotinic currents by lead. J.
Pharmacol. Exp. Ther. 273: 1471-1482.
Isolauri, E.; Huurre, A.; Salminen, S.; Impivaara, O. (2004) The allergy epidemic extends beyond the past few decades. Clin. Exp. A llergy. 34: 1007-1010.
Ito, Y.; Niiya, Y.; Kurita, H.; Shima, S.; Sarai, S. (1985) Serum lipid peroxide level and blood superoxide dismutase
activity in workers with occupational exposure to lead. Int. Arch. Occup. Environ. Health 56: 119-127.
Ito, S.; Ishii, K. J.; Ihata, A.; Klinman, D. M. (2005) Co ntribution of nitric oxide to CPG-mediated protection against

Listeria monocytogenes . Infect. Immun. 73: 3803-3805.
Ivanova-Chemishanska, L.; Antonov, G.; Khinkova, L.; Volcheva, Vl.; Khristeva, V. (1980) Deistvie na oloviniya atsetat v"rkhu reproduktsiyata na m"zhki beli pl"khove [Effect of lead acetate on reproduction in male white
rats]. Khig. Zdraveopaz. 23: 304-308.

Jacobs, J. M.; Sinclair, P. R.; Sinclair , J. F.; Gorman, N.; Walton, H. S.; Wood , S. G.; Nichols, C. (1998) Formation of zinc protoporphyrin in cultured hepatocytes: effects of ferrochelatase inhibition, iron chelation or lead.
Toxicology 125: 95-105. Jacquet, P. (1976) Effets du plomb administre durant la gestation a des souris C57B1 [Effects of lead administered
during the gestation period of mice C57B1]. C. R. Seances Soc. Biol. Ses Fil. 170: 1319-1322.
Jacquet, P. (1977) Early embryonic development in lead -intoxicated mice. Arch. Pathol. Lab. Med. 101: 641-643.

# AX5-210 Jacquet, P.; Leonard, A.; Gerber, G. B. (1975) Embryonic death in mouse due to lead exposure. Experientia

31: 24-25. Jacquet, P.; Leonard, A.; Gerber, G. B. (1976) Action of lead on early divisions of the mouse embryo. Toxicology

6: 129-132. Jacquet, P.; Gerber, G. B.; Maes, J. (1977) Biochemical studies in embryos after exposure of pregnant mice to dietary lead. Bull. Environ. Contam. Toxicol. 18: 271-277.
Jagetia, G. C.; Aruna, R. (1998) Effect of various concentrations of lead nitrate on the induction of micronuclei in

mouse bone marrow. Mutat. Res. 415: 131-137. Jehan, Z. S.; Motlag, D. B. (1995) Metal induced changes in the erythrocyte membrane of rats. Toxicol. Lett.

78: 127-133. Jemal, A.; Graubard, B. I.; Devesa, S. S.; Flegal, K. M. (2002) The association of blood lead level and cancer mortality among whites in the United States. Environ. Health Perspect. 110: 325-329.
Jett, D. A.; Kuhlmann, A. C.; Guilarte, T. R. (1997) Intrahippocampal administration of lead (Pb) impairs performance of rats in the Morris water maze. Pharmacol. Biochem. Behav. 57: 263-269.

Jett, D. A.; Beckles, R. A.; Navoa, R. V.; McLemore, G. L. (2002) Increased high-affinity nicotinic receptor-binding
in rats exposed to lead during development. Neurotoxicol. Teratol. 24: 805-811.
Johansson, L. (1989) Premature acrosome reaction in spermatozoa from lead-exposed mice. Toxicology

54: 151-162.
Johansson, L.; Pellicciari, C. E. (1988) Lead-induced ch anges in the stabilization of the mouse sperm chromatin. Toxicology 51: 11-24.
Johansson, L.; Wide, M. (1986) Long-ter m exposure of the male mouse to lead: effects on fertility. Environ. Res.

41: 481-487. Johansson, L.; Sjoblom, P.; Wide, M. (1987) Effects of lead on the male mouse as investigated by in vitro
fertilization and blastocyst culture . Environ. Res. 42: 140-148.
Jones, M. M.; Basinger, M. A.; Gale, G. R.; Atkins, L. M.; Smith, A. B.; Stone, A. (1994) Effect of chelate treatments on kidney, bone and brain levels of lead-intoxicated mice. Toxicology 89: 91-100.
Joseph, C. L. M.; Havstad, S.; Ownby, D. R.; Peters on, E. L.; Maliarik, M.; McCabe, J., M.J.; Barone, C.;
Johnson, C. C. (2005) Blood lead levels and risk of asthma. Environ. Health Perspect. 113: 900-904. Jover, R.; Lindberg, R. L. P.; Meyer, U. A. (1996) Role of heme in cytochrome P450 transcription and function in

mice treated with lead acetate. Mol. Pharmacol. 50: 474-481. Junaid, M.; Chowdhuri, D. K.; Narayan, R.; Shanker, R.; Saxena, D. K. (1997) Lead-induced changes in ovarian follicular development and maturation in mice. J. Toxicol. Environ. Health 50: 31-40.
Kaji, T.; Yamamoto, C.; Sakamoto, M. (1991) Effect of lead on the glycosaminoglycans metabolism of bovine aortic endothelial cells in culture. Toxicology 68: 249-257.
Kaji, T.; Yamamoto, C.; Sakamoto, M.; Kozuka, H. (1992) Inhibitory effect of lead on the release of tissue
plasminogen activator from human vascular endothelial cells in culture. Toxicology 73: 219-227. Kaji, T.; Suzuki, M.; Yamamoto, C.; Mishima, A.; Sakamo to, M.; Kozuka, H. (1995a) Severe damage of cultured
vascular endothelial cell monolayer after simultaneo us exposure to cadmium and lead. Arch. Environ.

Contam. Toxicol. 28: 168-172. Kaji, T.; Fujiwara, Y.; Hoshino, M.; Yamamoto, C.; Sakamoto , M.; Kozuka, H. (1995b) Inhibitory effect of lead on
the proliferation of cultured vascular endothelial cells. Toxicology 95: 87-92.
Kaji, T.; Ohkawara, S.; Nakajima, M.; Yamamoto, C.; Fujiwa ra, Y.; Miyajima, S.; Koizumi, F. (1997) Lead-induced alteration of heparan sulfate proteoglycans in culture d vascular endothelial cells. Toxicology 118: 1-10.
Kala, S. V.; Jadhav, A. L. (1995) Low level lead exposure decreases in vivo release of dopamine in the rat nucleus
accumbens: a microdialysis study. J. Neurochem. 65: 1631-1635. Kanduc, D.; Prisco, M. (1992) Hepatic DNA methylation in young, middle-aged, and sene scent rats: the effect of
mitogen-induced cell proliferation. Biochem. Med. Metab. Biol. 48: 286-291.

Kanduc, D.; Rossiello, M. R.; Aresta, A.; Cavazza, C.; Quagliariello, E.; Farber, E. (1991) Transitory DNA hypomethylation during liver cell proliferation induced by a single dose of lead nitrate. Arch. Biochem.
Biophys. 286: 212-216.

Kanitz, M. H.; Witzmann, F. A.; Zhu, H.; Fultz, C. D.; Skaggs, S.; Moorman, W. J.; Savage, R. E., Jr. (1999) Alterations in rabbit kidney protein expression following lead exposure as analyzed by two-dimensional gel
electrophoresis. Electrophoresis 20: 2977-2985.
Karbownik, M.; Tan, D.-X.; Reiter, R. J. (2000) Mela tonin reduces the oxidation of nuclear DNA and membrane
lipids induced by the carcinogen δ -aminolevulinic acid. Int. J. Cancer 88: 7-11.

# AX5-211 Karmakar, N.; Anand, S. (1989) Study of the inhibitory effect of lead acet ate on duodenal contractility in rat. Clin.
Exp. Pharmacol. Physiol. 16: 745-750. Karmakar, N.; Saxena, R.; Anand, S. (1986) Histopathological changes induced in rat tissues by oral intake of lead

acetate. Environ. Res. 41: 23-28.

Karmaus, W.; Brooks, K. R.; Nebe, T.; Witten, J.; Obi-Osiu s, N.; Kruse, H. (2005) Immune function biomarkers in children exposed to lead and organochlorine compounds: a cross-sectional study. Environ. Health Glob.

Access Sci. 4: 1-10.
Kato, Y.; Takimoto, S.; Ogura, H. (1977) Mechanism of induction of hypercalcemia and hyperphosphatemia by lead

acetate in the rat. Calcif. Tissue Res. 24: 41-46.
Kauppinen, T.; Riala, R.; Seitsamo, J.; Hernberg, S. (1992 ) Primary liver cancer and occupational exposure. Scand.

J. Work Environ. Health. 18: 18-25.

Kelada, S. N.; Shelton, E.; Kaufma nn, R. B.; Khoury, M. J. (2001) δ -aminolevulinic acid dehydratase genotype and
lead toxicity: a HuGE review. Am. J. Epidemiol. 154: 1-13. Keller, C. A.; Doherty, R. A. (1980) Bone lead mobilization in lactating mice and lead transfer to suckling offspring.
Toxicol. Appl. Pharmacol. 55: 220-228.
Kempe, D. A.; Lang, P. A.; Eisele, K.; Klarl, B. A.; Wi eder, T.; Huber, S. M.; Duranton, C.; Lang, F. (2005) Stimulation of erythrocyte phosphatidylserine exposure by lead ions. Am. J. Physiol. 288: C396-C402.
Kempinas, W. G.; Lamano-Carvalho, T. L.; Petenusci, S. O. ; Lopes, R. A.; Azoubel, R. (1988) Morphometric and
stereological analysis of rat testis and epididymis in an early phase of saturnism. Exp. Biol. 8: 51-56. Kempinas, W. G.; Melo, V. R.; Oliveira-Filho, R. M.; Sa ntos, A. C.; Favaretto, A. L.; Lamano-Carvalho, T. L.
(1990) Saturnism in the male rat: endocrine effects. Braz. J. Med. Biol. Res. 23: 1171-1175.
Kempinas, W. G.; Favaretto, A. L. V.; Melo, V. R.; Lamano Ca rvalho, T. L.; Petenusci, S. O.; Oliveira-Filho, R. M. (1994) Time-dependent effects of lead on rat reproductive functions. J. Appl. Toxicol. 14: 427-433.
Kennedy, G. L.; Arnold, D. W.; Calandra, J. C. (1975) Te ratogenic evaluation of lead compounds in mice and rats.

Food Cosmet. Toxicol. 13: 629-632. Keogh, J. P.; Steffen, B.; Siegers, C.-P. (1994) Cytotoxicity of heavy metals in the human small intestinal epithelial
cell line I-407: the role of glutathione. J. Toxicol. Environ. Health 43: 351-359.
Kern, M.; Audesirk, G. (1995) Inorganic lead may inhibit neurite development in cultured rat hippocampal neurons through hyperphosphorylation. Toxicol. Appl. Pharmacol. 134: 111-123.
Kern, M.; Audesirk, G. (2000) Stimulatory and inhibitory effects of inorganic lead on calcineurin. Toxicology

150: 171-178. Kerper, L. E.; Hinkle, P. M. (1997) Cellular uptake of lead is activated by depletion of intracellular calcium stores.

J. Biol. Chem. 272: 8346-8352.

Khalil-Manesh, F.; Gonick, H. C. Cohen, A. H.; Alinovi, R.; Bergamaschi, E.; Mutti, A.; Rosen, V. J. (1992a)
Expermiental model of lead nephropathy. I. Continuous high-dose lead administration. Kidney Int.

41: 1192-1203. Khalil-Manesh, F.; Gonick, H. C.; Cohen, A.; Bergamasch i, E.; Mutti, A. (1992b) Experimental model of lead
nephropathy. II. Effect of removal from lead exposure and chelation treatment w ith dimercaptosuccinic acid
(DMSA). Environ. Res 58: 35-54.

Khalil-Manesh, F.; Gonick, H. C.; Weiler, E. W. J.; Prins, B.; Weber, M. A.; Purdy, R. E. (1993a) Lead-induced
hypertension: possible role of endothelial factors. Am. J. Hypertens. 6: 723-729.
Khalil-Manesh, F.; Gonick, H. C.; Cohen, A. H. (1993b) Ex perimental model of lead nephropathy. III. Continuous

low-level lead administration. Arch. Environ. Health 48: 271-278.

Khalil-Manesh, F.; Gonick, H. C.; Weiler, E. W. J.; Prins, B.; Weber, M. A.; Pu rdy, R.; Ren, Q. (1994) Effect of

chelation treatment with di mercaptosuccinic acid (DMSA) on lead-relat ed blood pressure changes. Environ.

Res. 65: 86-99. Khan, M. Z.; Szarek, J. (1994) Effects of concurrent oral administration of lead, selenium or monensin on hepatic
porphyrin levels in broiler chickens during sub-acute toxicosis. J. Vet. Med. B. 41: 77-82. Kim, D.; Lawrence, D. A. (2000) Immunotoxic effects of inorganic lead on host resistance of mice with different
circling behavior preferences. Brain Behav. Immun. 14: 305-317.
Kim, J. S.; Hamilton, D. L.; Blakley, B. R.; Rousseaux, C. G. (1992) The effects of thiamin on lead metabolism: organ distribution of lead 203. Can. J. Vet. Res. 56: 256-259.
Kim, R.; Rotnitsky, A.; Sparrow, D.; Wei ss, S. T.; Wager, C.; Hu, H. (1996) A longitudinal study of low-level lead exposure and impairment of renal function. The Normative Aging Study. JAMA J. Am. Med. Assoc.

275: 1177-1181.

# AX5-212 Kim, K. A.; Chakraborti, T.; Goldstein, G. W.; Bressler, J. P. ( 2000) Immediate early gene expression in PC12 cells
exposed to lead: requirement for protein kinase C. J. Neurochem. 74: 1140-1146. Kim, H.-S.; Lee, S.-S.; Lee, G.-S.; Hwangbo, Y.; Ahn, K.-D.; Lee, B.-K. (2004) The protective effect of

δ -aminolevulinic acid dehydratase 1-2 and 2-2 isozymes against blood lead with higher hematologic
parameters. Environ. Health Perspect. 112: 538-541. Kimber, I.; Stonard, M. D.; Gidlow, D. A.; Niewola, Z. (1986) Influence of chronic low-level exposure to lead on
plasma immunoglobulin concentration and cellular immune function in man. Int. Arch. Occup. Environ.

Health 57: 117-125.

Kimmel, C. A.; Grant, L. D.; Sloan, C. S.; Gladen, B. C. (1980) Chronic low-level lead toxicity in the rat.
I. Maternal toxicity and perinatal effect s. Toxicol. Appl. Pharmacol. 56: 28-41.
Kiremidjian-Schumacher, L.; Stotzky, G. ; Dickstein, R. A.; Schwartz, J. (1 981) Influence of cadmium, lead, and zinc on the ability of guinea pig macrophages to interact with macrophage migration inhibitory factor.

Environ. Res. 24: 106-116. Kishikawa, H.; Lawrence, D. A. (1998) Differential production of interleukin-6 in the brain and spleen of mice
treated with lipopolysacchar ide in the presence and absence of l ead. J. Toxicol. Environ. Health A

53: 357-373. Kishikawa, H.; Song, R.; Lawrence, D. A. (1997) Interleukin-12 promotes enhanced resistance to Listeria

monocytogenes infection of lead-exposed mice. To xicol. Appl. Pharm acol. 147: 180-189.
Kishimoto, T.; Oguri, T.; Ueda, D.; Tada, M. (1995) Effect of lead on tube formation by cultured human vascular

endothelial cells. Arch. Toxicol. 69: 718-721.
Klann, E.; Shelton, K. R. (1989) The effect of lead on the metabolism of a nuclear matrix protein which becomes
prominent in lead-induced intranuclear inclusion bodies. J. Biol. Chem. 264: 16,969-16,972.
Klann, E.; Shelton, K. R. (1990) A lead-associated nuclear protein which increases in maturing brain and in
differentiating neuroblastoma 2A cells exposed to cyc lic AMP-elevating agents. Dev. Brain Res. 57: 71-75.
Klein, R. F.; Wiren, K. M. (1993) Regulation of os teoblastic gene expression by lead. Endocrinology

132: 2531-2537. Klein, D.; Wan, Y.-J. Y.; Kamyab, S.; Okuda, H.; Sokol, R. Z. (1994) Effects of toxic levels of lead on gene
regulation in the male axis: increase in messenger ribo nucleic acids and intracellula r stores of gonadotrophs within the central nervous system. Biol. Reprod. 50: 802-811.
Kleszcy ń ska, H.; Hladyszowski, J.; Pruchnik, H.; Przestalski, S. (1997) Erythrocyte hemolysis by organic tin and
lead compounds. Z. Naturforsch. C: J. Biosci. 52: 65-69. Knowles, S. O.; Donaldson, W. E. (1990) Dietary modifica tion of lead toxicity: effects on fatty acid and eicosanoid
metabolism in chicks. Comp. Biochem. Physiol. C 95: 99-104. Knowles, S. O.; Donaldson, W. E. (1997) Lead disrupts eicosanoid metabolism, macrophage function, and disease

resistance in birds. Biol. Trace Elem. Res. 60: 13-26.
Kobayashi, N.; Okamoto, T. (1974) Effects of lead oxide on the induction of lung tumors in Syrian hamsters. J. Natl.

Cancer Inst. 52: 1605-1610. Kober, T. E.; Cooper, G. P. (1976) Lead competitively inhibits calcium-dependent synaptic transmission in the
bullfrog sympathetic ganglion. Nature (London) 262: 704-705. Kojima, M.; Nemoto, K.; Murai, U.; Yoshimura, N.; Ayabe, Y.; Degawa, M. (2002) Altered gene expression of
hepatic lanosterol 14 x -demethylase (CYP51) in lead nitrate-tr eated rats. Arch. Toxicol. 76: 398-403.
Kojima, M.; Masui, T.; Nemoto, K.; Degawa, M. (2004) Le ad nitrate-induced developmen t of hypercholesterolemia in rats: sterol-independent gene regulation of hepatic enzymes responsible for cholesterol homeostasis.

Toxicol. Lett. 154: 35-44.
Koller, L. D. (1973) Immunosuppression produced by lead, cadmium, and mercury. Am. J. Vet. Res. 34: 1457-1458.
Koller, L. D.; Kovacic, S. (1974) D ecreased antibody formation in mice exposed to lead. Nature 250: 148-150.
Koller, L. D.; Roan, J. G. (1980) Effects of lead, cadmium and methylmercury on immunological memory.

J. Environ. Pathol. Toxicol. 4: 47-52. Koller, L. D.; Exon, J. H.; Roan, J. G. (1976) Humoral antibody response in mice after single dose exposure to lead
or cadmium. Proc. Soc. Exp. Biol. Med. 151: 339-342.

Koller, L. D.; Roan, J. G.; Brauner, J. A.; Exon, J. H. (1977) Immune response in aged mice exposed to lead.

J. Toxicol. Environ. Health 3: 535-543.
Konantakieti, C.; Beuthin, F. C.; Louis-Ferdinand, R. T. (1986) Erythrocyte pyrimidine 5'-nucleotidase inhibition by acute lead exposure in neonatal ra ts. J. Biochem. Toxicol. 1: 51-59.
Koo, P.; Nagai, M. K.; Farber, E. (1994) Multiple sites of control of glutathione S -transferase P1-1 in rat liver.

J. Biol. Chem. 269: 14601-14606.

# AX5-213 Korashy, H. M.; El-Kadi, A. O. S. (2004) Differential effects of mercury, lead and copper on the constitutive and
inducible expression of aryl hydrocarbon receptor (AHR)-regulated genes in cultured hepatoma Hepa 1c1c7 cells. Toxicology 201: 153-172.

Kostial, K.; Blanuša, M.; Piasek, M.; Re stek-Samaržija, N.; Jones, M. M.; Sing h, P. K. (1999) Combined chelation
therapy in reducing tissue lead c oncentrations in suckling rats. J. Appl. Toxicol. 19: 143-147. Kowolenko, M.; Tracy, L.; Mudzinski, S.; Lawrence, D. A. (1988) Effect of lead on macrophage function.
J. Leukocyte Biol. 43: 357-364.
Kowolenko, M.; Tracy, L.; Lawrence, D. A. (1989) Lead-in duced alterations of in vitro bone marrow cell responses to colony stimulating factor-1. J. Leukocyte Biol. 45: 198-206.
Kowolenko, M.; Tracy, L.; Lawrence, D. (1991) Early effe cts of lead on bone marrow cell responsiveness in mice
challenged with Listeria monocytogenes . Fundam. Appl. Toxicol. 17: 75-82.

Kramer, H. J.; Gonick, H. C.; Lu, E. (1986) In vitro inhi bition of Na-K-ATPase by trace metals: relation to renal and
cardiovascular damage. Nephron 44: 329-336. Kristensen, P.; Andersen, A. (1992) A cohort study on cancer incidence in offspring of male printing workers.
Epidemiology 3: 6-10.

Kristensen, P.; Eilertsen, E.; Einarsdóttir , E.; Øvrebø, S.; Haugen, A. (1993) Effect modification by inorganic lead in
the dominant lethal assay. Mutat. Res. 302: 33-38.
Krocova, Z.; Macela, A.; Kroca, M.; Hernychova, L. (2 000) The immunomodulatory effect (s) of lead and cadmium
on the cells of immune system in vitro . Toxicol. In Vitro. 14: 33-40. Kubo, Y.; Yasunaga, M.; Masuhara, M.; Te rai, S.; Nakamura, T.; Okita, K. (199 6) Hepatocyte proliferation induced
in rats by lead nitrate is suppresse d by several tumor necrosis factor α inhibitors. Hepatology 23: 104-114.
Kuhlmann, A. C.; McGlothan, J. L.; Guilarte, T. R. (199 7) Developmental lead exposure causes spatial learning

deficits in adult rats. Neurosci. Lett. 233: 101-104.
Kumar, K. V.; Das, U. N. (1993) Are free radicals involved in the pathobiology of human essential hypertension?

Free Radical Res. Commun. 19: 59-66. Kumar, P.; Rai, G. P.; Flora, S. J. S. (1994) Immunomodulation following zinc supplementation during chelation of

lead in male rats. Biometals 7: 41-44.

Lai, C.-C.; Lin, H. H.; Chen, C. W.; Chen, S.-H.; Chiu, T. H. (2002) Excitatory action of lead on rat sympathetic preganglionic neurons in vitro and in vivo. Life Sci. 71: 1035-1045.
Lake, L.; Gerschenson, L. E. (1978) Cellular and molecular toxicology of lead. III. Effect of lead on heme synthesis.

J. Toxicol. Environ. Health 4: 527-540.

Lal, B.; Goldstein, G.; Bressler, J. P. (1996) Role of anion exchange and thiol groups in the regulation of potassium
efflux by lead in human erythrocytes. J. Cell Physiol. 167: 222-228. Lara-Tejero, M.; Pamer, E. G. (2004) T cell responses to Listeria monocytogenes . Curr. Opin. Microbiol. 7: 45-50. Larsson, Å. (1974) Studies on dentinogenesis in the ra t. The interaction between lead-pyrophosphate solutions and
dentinal globules. Calcif. Tiss. Res. 16: 93-107. Larsson, Å.; Helander, H. F. (1974) Studies on dentinogenesis in the rat. Light, electron microscopic and

histochemical studies on the interaction between lead pyrophosphate solutions and dentin-producing tissues.

Calcif. Tiss. Res. 14: 87-104. Laschi-Loquerie, A.; Decotes, J.; Tach on, P.; Evreux, J. C. (1984) Influence of lead acetate on hypersensitivity
experimental study. J. Immunopharmacol. 6: 87-93.
Lasky, R. E.; Laughlin, N. K. (2001) Exploring a partially enclosed space by lead-exposed female rhesus monkeys.

Neurotoxicol. Teratol. 23: 177-183.
Lasley, S. M.; Gilbert, M. E. (1996) Presynaptic glutamatergic function in dentate gyrus in vivo is diminished by
chronic exposure to inorganic lead. Brain Res. 736: 125-134. Lasley, S. M.; Gilbert, M. E. (1999) Lead inhibits the rat N -methyl- D 

# -aspartate receptor channel by binding to a site

distinct from the zinc allosteric site. Toxicol. Appl. Pharmacol. 159: 224-233.
Lasley, S. M.; Gilbert, M. E. (2000) Glutamatergic components underlying lead-induced impairments in hippocampal synaptic plasticity. Neurotoxicology 21: 1057-1067.
Lasley, S. M.; Gilbert, M. E. (2002) Rat hippocampal glutamate and GABA re lease exhibit biphasic effects as a
function of chronic lead exposure level. Toxicol. Sci. 66: 139-147. Lasley, S. M.; Green, M. C.; Gilbert, M. E. (1999) Influence of exposure period on in vivo hippocampal glutamate
and GABA release in rats chronically exposed to lead. Neurotoxicology 20: 619-629. Lasley, S. M.; Green, M. C.; Gilbert, M. E. (2001) Rat hippocampal NMDA receptor binding as a function of
chronic lead exposure level. Neurotoxicol. Teratol. 23: 185-189.

# AX5-214 Laughlin, N. K.; Bowman, R. E.; Franks, P. A.; Dierschke, D. J. (1987) Altered menstura l cycles in rhesus monkeys
induced by lead. Fundam. Appl. Toxicol. 9: 722-729. Laughlin, N. K.; Bushnell, P. J.; Bowman, R. E. (1991) Lead exposure and diet: differential effects on social
development in the rhesus monkey. Neurotoxicol. Teratol. 13: 429-440.
Laughlin, N. K.; Lasky, R. E.; Giles, N. L.; Luck, M. L. (1999) Lead effects on neurobehavioral development inthe neonatal rhesus monkey ( Macaca mulatta ). Neurotoxicol. Teratol. 21: 627-638.
Lauwerys, R.; Bernard, A.; Cardenas, A. (1992) Monitoring of early nephrotoxic effects of industrial chemicals.

Toxicol. Lett. 64-65: 33-42. Lawler, E. M.; Duke, G. E.; Redig, P. T. (1991) Effect of sublethal lead exposure on gastric motility of red-tailed

hawks. Arch. Environ. Contam. Toxicol. 21: 78-83.
Lawrence, D. A. (1981a) Heavy metal modulation of lympho cyte activities. I. In vitro effects of heavy metals on primary humoral immune responses. Toxicol. Appl. Pharmacol. 57: 439-451.
Lawrence, D. A. (1981b) Heav y metal modulation of lymphocyte activities - II: lead, an in vitr o mediator of B-cell activation. Int. J. Immunopharmacol. 3: 153-161.
Lawrence, D. A. (1981c) In vivo and in vitro effects of lead on humoral and cell- mediated immunity. Infect.

Immun. 31: 136-143. Lawrence, D. A.; Kim, D. (2000) Central/peripheral nervous system and immune responses. Toxicology

142: 189-201. Lawrence, D. A.; McCabe, M. J., Jr. (2002) Immunomodulation by metals. Int. Immunopharmacol. 2: 293-302.

Ledda-Columbano, G. M.; Coni, O.; Curt o, M.; Giacomini, O.; Faa, G.; Sarma, D. S. R.; Columbano, A. (1992)
Mitogen-induced liver hyperplasia does not substitute for compensatory regeneration during promotion of
chemical hepatocarcinogenesis. Carcinogenesis 13: 379-383.

Ledda-Columbano, G. M.; Columbano, A.; Cannas, A.; Simbul a, G.; Okita, K.; Kayano, K.; Kubo, Y.; Katyal, S. L.;
Shinozuka, H. (1994) Dexamethasone inhibits induction of liver tumor necrosis factor- α mRNA and liver
growth induced by lead nitrate and ethylene dibromide. Am. J. Pathol. 145: 951-958.
Lee, J. J.; Battles, A. H. (1994) Lead toxicity via arachidonate signal transduction to growth responses in the splenic
macrophage. Environ Res. 67: 209-219.
Lee, J.-E.; Dietert, R. R. (2003) Developmental immunotoxicity of lead: impact on thymic function. Birth Defects

Res. A Clin. Mol. Teratol. 67: 861-867.

Lee, J.-E.; Chen, S.; Golemboski, K. A.; Parsons, P. J.; Di etert, R. R. (2001) Developmental windows of differential
lead-induced immunotoxicity in chickens. Toxicology 156: 161-170. Lee, J.-E.; Naqi, S. A.; Kao, E.; Dietert, R. R. (2002 ) Embryonic exposure to lead: Comparison of immune and
cellular responses in unchallenged and virally stressed chickens. Arch Toxicol. 75: 717-724. Levin, E. D.; Bowman, R. E. (1986) Long -term lead effects on the Hamiliton Se arch Task and delayed alternation in
monkeys. Neurobehav. Toxicol. Teratol. 8: 219-224.
Levin, E. D.; Bowman, R. E. (1989) Long-term effects of chronic postnatal lead exposure on delayed spatial alternation in monkeys. Neurotoxicol. Teratol. 10: 505-510.
Levin, E. D.; Bowman, R. E.; Wegert, S.; Vuchetich, J. (1987) Psychopharmacological investigations of a leadinduced long-term cognitive deficit in monkeys. Psychopharmacology 91: 334-341. Levin, E. D.; Schneider, M. L.; Ferguson, S. A.; Schantz, S. L.; Bowman, R. E. (1988) Behavioral effects of
developmental lead exposure in rhesus monkeys. Dev. Psychobiol. 21: 371-382.

Lilienthal, H.; Winneke, G. (1996) Lead effects on the br ain stem auditory evoked potential in monkeys during and after the treatment phase. Neur otoxicol. Teratol. 18:17-32.

Lilienthal, H.; Winneke, G.; Brockhaus, A.; Molik, B. ( 1986) Pre- and postnatal lead-exposure in monkeys: effects
on activity and learning set formation. Neurobehav. Toxicol. Teratol. 8: 265-272.

Lilienthal, H.; Lenaerts, C.; Winneke, G.; Hennekes, R. (1988) Alteration of the visual evoked potential and the
electroretinogram in lead-treated monkeys. Neurotoxicol. Teratol. 10: 417-422.
Lin, R. H.; Lee, C. H.; Chen, W. K.; Lin-Shiau, S. Y. (1994) Studies on cytotoxic and genotoxic effects of cadmium

nitrate and lead nitrate in Chinese hamster ovar y cells. Environ. Mol. Mutagen. 23: 143-149.
Lindahl, L. S.; Bird, L.; Legare, M. E.; Mikeska, G.; Bra tton, G. R.; Tiffany-Castiglio ni, E. (1999) Differential
ability of astroglia and neuronal cells to accumulat e lead: dependence on cell type and on degree of

differentiation. Toxicol Sci. 50: 236-243.
Liu, J.; Kershaw, W. C.; Klaassen, C. D. (1991) The protec tive effect of metallothionein on the toxicity of various metals in rat primary hepatocyte culture. Toxicol. Appl. Pharmacol. 107: 27-34.

# AX5-215 Liu, J.-Y.; Lin, J.-K.; Liu, C.-C.; Chen, W.-K.; Liu, C.-P.; Wang, C.-J .; Yen, C.-C.; Hsieh, Y.-S. (1997)
Augmentation of protein kinase C activity and liver cell proliferation in lead nitr ate-treated rats. Biochem.

Mol. Biol. Int. 43: 355-364.
Liu, M. Y.; Hsieh, W. C.; Yang, B. C. (2000) In vitro aberrant gene expression as the indicator of lead-induced
neurotoxicity in U-373MG cells. Toxicology 147: 59-64. Liu, M.-Y.; Lai, H.-Y.; Yang, B.-C.; Tsai, M.-L.; Yang, H.-Y.; Huang, B.-M. (2001) The inhibitory effects of lead
on steroidogenesis in MA-10 mouse Leydig tumor cells. Life Sci. 68: 849-859.
Liu, M. Y.; Leu, S. F.; Yang, H. Y.; Huang, B. M. (2003) Inhibitory mechanisms of lead on steroidogenesis in MA10 mouse Leydig tumor cells. Arch. Androl. 49: 29-38.
Lögdberg, B.; Berlin, M.; Schütz, A. (1987) Effects of lead exposure on pregnancy outcome and the fetal brain of
squirrel monkeys. Scand. J. Work Environ. Health 13: 135-145. Lögdberg, B.; Brun, A.; Berlin, M.; Schütz, A. (1988) Congenital lead encephalopathy in monkeys. Acta
Neuropathol. 77: 120-127. Loipführer, A. M.; Reichlmayr-Lais, A. M.; Kirchgessner, M. (1993) Concentra tion of free calcium in erythrocytes
of lead-depleted rats. J. Trace Elem. Electrolytes Health Dis. 7: 37-40.
Lolin, Y.; O’Gorman, P. (1988) An intra-erythrocyctic low molecular weight lead-binding protein in acute and chronic lead exposure and its possible protective role in lead toxicity. Ann. Clin. Biochem. 25: 688-97.
Long, G. J.; Rosen, J. F. (1992) L ead perturbs epidermal growth factor (EGF) modulation of intracellular calcium
metabolism and collagen synthesis in clonal rat osteoblastic (ROS 17/2.8) cells. Toxicol. Appl. Pharmacol.

114: 63-70. Long, G. J.; Rosen, J. F.; Pounds, J. G. (1990) Lead im pairs the production of osteocalcin by rat osteosarcoma
(ROS 17/2.8) cells. Toxicol. Appl. Pharmacol. 106: 270-277. Long, G. J.; Pounds, J. G.; Rosen, J. F. (1992) Lead intoxication alters basal and parathyroid hormone-regulated
cellular calcium homeostasis in rat osteosarcoma (ROS 17/2.8) cells. Calcif. Tissue Int. 50: 451-458.
Long, G. J.; Rosen, J. F.; Schanne, F. A. X. (1994) Lead activation of protein kinase C from rat brain. Determination of free calcium, lead, and zinc by 19F NMR. J. Biol. Chem. 269: 834-837.
Lu, H.; Guizzetti, M.; Costa, L. G. ( 2002) Inorganic lead activates the mitogen-activated protein kinase kinasemitogen-activated protein kinase-p90RSK signaling pathway in human astrocytoma cells via a protein kinase C-dependent mechanism. J. Pharmacol. Exp. Ther.300: 818-823.
Luster, M. I.; Faith, R. E.; Kimmel, C. A. (1978) Depression of humoral immunity in rats following chronic
developmental lead exposure. J. Environ. Pathol. Toxicol. 1: 397-402.

Luster, M. I.; Portier, C.; Pait, D. G.; White, K. L. J.; Ge nnings, C.; Munson, A. E.; Rosenthal, G. J. (1992) Risk
assessment in immunotoxicology. I. Sensitivity and predictability of immune tests. Fund. Appl. Toxicol.

18: 200-210.

Lutz, P. M.; Wilson, T. J.; Ireland, A. L.; Gorman, J. S.; Gale, N. L.; Johnson, J. C.; Hewett, J. E. (1999) Elevated
immunoglobulin E (IgE) levels in children with exposure to environmental lead. Toxicology 134: 63-78. Ma, T.; Chen, H. H.; Chang, H. L.; Hume, A. S.; Ho, I. K. (1997) Effects of chronic lead exposure on [3H]MK-801
binding in the brain of rat. Toxicol. Lett. 92: 59-66.
Madden, E. F.; Fowler, B. A. (2000) Mechanisms of nephrotoxicity from metal combinations: a review. Drug Chem.

Toxicol. 23: 1-12.
Maezawa, Y.; Nakajima, H.; Seto, Y.; Suto, A.; Kumano, K.; Kubo, S.; Karasuyama, H.; Saito, Y.; Iwamoto, I.
(2004) IgE-dependent enhancement of Th2 cell-mediated allergic inflammation in the airways. Clin. Exp.

Immunol. 135: 12-18.
Mahaffey, K. R.; Fowler, B. A. (1977) Effects of concurrent administration of lead, cadmium, and arsenic in the rat.
Environ. Health Perspect. 19: 165-171. Mahaffey, K. R.; Capar, S. G.; Gladen, B. C.; Fowler, B. A. (1981) Concurrent exposure to lead, cadmium, and

arsenic. J. Lab. Clin. Med. 98: 463-481.
Maisin, J. R.; Lambiet-Collier, M.; De Saint-Georges, L. (1 978) Toxicite du plomb pour les embryons de la souris [Lead toxicity for mouse embryo s]. C. R. Seances Soc. Biol. Ses. Fil. 172: 1041-1043.

Maitani, T.; Watahiki, A.; Suzuki, K. T. (1986) Induction of metallothione in after lead administration by three
injection routes in mice. Toxicol. Appl. Pharmacol. 83: 211-217.

Maker, H. S.; Lehrer, G. M.; Silides, D. J. (1975) The effect of lead on mouse brain development. Environ. Res.

10: 76-91. Maldonado-Vega, M.; Cerbón-Solórzano, J.; Albores-Medi na, A.; Hernández-Luna, C.; Calderón-Salinas, J. V.
(1996) Lead: intestinal absorption and bone mobilizati on during lactation. Hum. Exp. Toxicol. 15: 872-877.

# AX5-216 Maldonado-Vega, M.; Cerbón-Solórzano, J.; Calderón-Salinas , J. V. (2002) The effect s of dietary calcium during
lactation on lead in bone mobilization: implications for toxicology. Hum. Exp. Toxicol. 21: 409-414.

Malvezzi, C. K.; Moreira, E. G.; Vass ilieff, I.; Vassilieff, V. S.; Cordellini, S. (2001) Effect of L-arginine,
dimercaptosuccinic acid (DMSA) and the association of L-arginine and DMSA on tissue lead mobilization
and blood pressure level in plumbism. Braz. J. Med. Biol. Res. 34: 1341-1346. Manton, W. I.; Angle, C. R.; Stanek, K. L.; Reese, Y. R.; Kuehnemann, T. J. (2000) Acquisition and retention of
lead by young children. Environ. Res. 82: 60-80.

Marchlewicz, M.; Protasowicki, M.; Ró ż ewicka, L.; Piasecka, M.; Laszczy ń ska, M. (1993) Effect of long-term exposure to lead on testis and epididymis in rats. Folia Histochem. Cytobiol. 31: 55-62.
Marcus, A. H. (1985a) Multicompartment kinetic models for lead. I. Bone diffusion models for long-term retention.

Environ. Res. 36: 441-458. Marcus, A. H. (1985b) Multicompartment kinetic models fo r lead. II. Linear kinetics and variable absorption in
humans without excessive lead exposures. Environ. Res. 36: 459-472. Marcus, A. H. (1985c) Multicompartment kinetic model for lead. III. Lead in blood plasma and erythrocytes.

Environ. Res. 36: 473-489.
Markovac, J.; Goldstein, G. W. (1988a) Lead activates protein kinase C in immature rat brain microvessels. Toxicol. Appl. Pharmacol. 95: 14-23.
Markovac, J.; Goldstein, G. W. (1988b) Picomolar concentrations of lead stimulate brain protein kinase C. Nature
(London, U.K.) 334: 71-73. Marques, M.; Millás, I.; Jiménez, A.; García-Colis, E.; Rodr iguez-Feo, J. A.; Velasco, S.; Barrientos, A.; Casado, S.;
López-Farré, A. (2001) Alteration of the soluble guany late cyclase system in the vascular wall of leadinduced hypertension in rats. J. Am. Soc. Nephrol. 12: 2594-2600.

Martins, M. B.; Sabatier, L.; Ricoul, M.; Pinton, A.; Dutr illaux, B. (1993) Specific chromosome instability induced
by heavy ions: a step towards transformation of human fibroblasts? Mutat. Res. 1285: 229-237.
Mas-Oliva, J. (1989) Effect of lead on the erythroc yte (Ca2+,Mg2+)-ATPase activity. Calmodulin involvement

. Mol. Cell. Biochem. 89: 87-93.
Massie, H. R.; Aiello, V. R. (1992) Lead accumulation in the bones of aging male mice. Gerontology 38: 13-17.
Mauël, J.; Ransijn, A.; Buchmüller-Rou iller, Y. (1989) Lead inhi bits intracellular killing of Leishmania parasites and extracellular cytolysis of targ et cells by macrophages exposed to macrophage activating factor.

J. Leukoc. Biol. 45: 401-409.

Mazzolini, M.; Traver so, S.; Marchetti, C. (2 001) Multiple pathways of Pb2+ pe rmeation in rat cerebellar granule

neurones. J. Neurochem. 79: 407-416.
McCabe, M. J., Jr. (1994) Mechanisms and consequences of immunomodulation by lead. In: Dean, J. H.; Luster, M. I.; Munson, A. E.; Kimber, I., eds. Immunotoxicology and immunopharmacology. 2nd ed. New
York, NY: Raven Press, Ltd.; pp. 143-162.
McCabe, M. J., Jr.; Lawrence, D. A. (1990) The heavy me tal lead exhibits B cell-stimulatory factor activity by enhancing B cell Ia expression and differentiation. J. Immunol. 145: 671-677.
McCabe, M. J.; Lawrence, D. A. (1991) Lead, a major environmental pollutant, is immunomodulatory by its
differential effects on CD4+ T cell subsets. Toxicol. Appl. Pharmacol. 111: 13-23.
McCabe, M. J., Jr.; Dias, J. A.; Lawrence, D. A. (1991) Lead influences translational or posttranslational regulation
of Ia expression and increases invariant chain expression in mouse B cells. J. Biochem. Toxicol. 6: 269-276.
McCabe, M. J., Jr.; Singh, K. P.; Reiners, J. J., Jr. (1999 ) Lead intoxication impairs the generation of a delayed type hypersensitivity response. Toxicology 139: 255-264.
McCabe, M. J., Jr.; Singh, K. P.; Reiners, J. J., Jr. (2001) Low level lead exposure in vitro stimulates the
proliferation and expansion of alloantigen-reactiv e CD4high T cells. Toxicol. Appl. Pharmacol.

177: 219-231. McClain, R. M.; Becker, B. A. (1972) Effects of organolead compounds on rat embryonic and fetal development.
Toxicol. Appl. Pharmacol. 21: 265-274.
McGivern, R. F.; Sokol, R. Z.; Berman, N. G. (1991) Pren atal lead exposure in the rat during the third week of
gestation: long-term behavioral, physiological and anatom ical effects associated w ith reproduction. Toxicol.
Appl. Pharmacol. 110: 206-215. McGowan, C.; Donaldson, W. E. (1987) Effect of lead toxicity on the organ concentration of glutathione and
glutathione-related free amino acids in the chick. Toxicol. Lett. 38: 265-270. McLachlin, J. R.; Goyer, R. A.; Cheria n, M. G. (1980) Formation of lead-induced inclusion bodies in primary rat
kidney epithelial cell cultures: effect of actinomyc in D and cycloheximide. Toxicol. Appl. Pharmacol.

56: 418-431.

# AX5-217 McMurry, S. T.; Lochmiller, R. L.; Chandra, S. A. M.; Qualls, C. W., Jr. (1995) Sensitivity of selected
immunological, hematological, and reproductive parameters in the cotton rat ( Sigmodon hispidus ) to subchronic lead exposure. J. Wildl. Dis. 31: 193-204.
McNeill, F. E.; Laughlin, N. K.; Todd, A. C.; Sonawane, B. R.; Van de Wal, K. M.; Fowl er, B. A. (1997) Geriatric
bone lead metabolism in a female nonhuman primate population. Environ. Res. 72: 131-139. McNeill, D. R.; Narayana, A.; Wong, H. K.; Wilson, D. M. III. (2004) Inhib ition of Ape1 nuclease activity by lead,
iron, and cadmium. Environ. Health Perspect. 112: 799-804.
Melchiorri, C.; Chieco, P.; Zedda, A. I.; Coni, P.; Ledda-Columbano, G. M.; Columbano, A. (1993) Ploidy and nuclearity of rat hepatocytes after compensatory regeneration or mitogen-induced liver growth.
Carcinogenesis 14: 1825-1830.
Menegazzi, M.; Carcereri De Prati, A.; Ledda-Columbano, G. M.; Colu mbano, A.; Uchida, K.; Miwa, M.; Suzuki, H. (1990) Regulation of poly(ADP-ribose) polymerase mRNA levels during compensatory and
mitogen-induced growth of rat liver. Arch. Biochem. Biophys. 279: 232-236. Menegazzi, M.; Carcereri de Prati, A.; Ogura, T.; Columbano, A.; Ledd a-Columbano, G. M.; Libonati, M.;
Esumi, H.; Suzuki, H. (1992) Involvement of DNA poly merase beta in proliferation of rat liver induced by
lead nitrate or partial hepatectomy. Febs. Lett. 310: 135-138. Menegazzi, M.; Carcereri-De Prati, A.; Suzuki, H.; Shinozuka, H.; Pibi ri, M.; Piga, R.; Columbano, A.;
Ledda-Columbano, G. M. (1997) Liver cell proliferation induced by nafenopin and cyproterone acetate is

not associated with increases in ac tivation of transcription factors NF- κ B and AP-1 or with expression of

tumor necrosis factor α . Hepatology 25: 585-592.
Miller, L.; Qureshi, M. A. (1992) Heat-shock protein synthesis in chicken macrophages: Influence of in vivo and

in vitro heat shock, lead acetate, and lipo polysaccharide. Poul. Sci. 71: 988-998.

Miller, T. E.; Golemboski, K. A.; Ha, R. S.; Bunn, T.; Sand ers, F. S.; Dietert, R. R. (1998) Developmental exposure
to lead causes persistent immunotoxicity in Fischer 344 rats. Toxicol. Sci. 42: 129-135.

Miller, D. K.; Nation, J. R.; Bratton, G. R. (2001) The effects of perinatal exposure to lead on the discriminative stimulus properties of cocaine and related drugs in rats. Psychopharmacology (Berl). 158: 165-174.
Milosevic, N.; Maier, P. (2000) Lead stimulates interce llular signalling between hepatocytes and Kupffer cells. Eur.

J. Pharmacol. 401: 317-328. Minnema, D. J.; Hammond, P. B. (1994) Effect of lead exposure on patterns of food intake in weanling rats.

Neurotoxicol. Teratol. 16: 623-629.
Minozzo, R.; Deimling, L. I.; Gigante, L. P.; Santos-Mello, R. (2004) Micronuclei in peripheral blood lymphocytes of workers exposed to lead. Mutat. Res. 565: 53-60.
Mishra, M.; Acharya, U. R. (2004) Protective action of vitamins on the spermatogenesis in lead-treated Swiss mice.

J. Trace Elem. Med. Biol. 18: 173-178.
Mishra, K. P.; Singh, V. K.; Rani, R.; Yadav, V. S.; Chan dran, V.; Srivastava, S. P.; Seth, P. K. (2003) Effect of
lead exposure on the immune response of some occupationally exposed individuals. Toxicology

188: 251-259. Mistry, P.; Lucier, G. W.; Fowler, B. A. (1985) High-affin ity lead binding proteins in rat kidney cytosol mediate

cell-free nuclear translocation of lead. J. Pharmacol. Exp. Ther. 232: 462-469. Mistry, P.; Mastri, C.; Fowler, B. A. (1986) Influence of metal ions on renal cytosolic lead-binding proteins and
nuclear uptake of lead in the kidney. Biochem. Pharmacol. 35: 711-713.
Miyahara, T.; Komiyama, H.; Miyanishi, A.; Takata, M. ; Nagai, M.; Kozuka, H.; Hayashi, T.; Yamamoto, M.;
Ito, Y.; Odake, H.; Koizumi, F. (1995) Stimulative effects of lead on bone resorption in organ culture.
Toxicology 97: 191-197.
Mobarak, N.; P'an, A. Y. (1984) Lead distribution in th e saliva and blood fractions of rats after intraperitoneal injections. Toxicology 32: 67-74.
Mojzis, J.; Nistiar, F. (2001) Lead-induced changes of cation-osmotic hemolysis in rats. Gen. Physiol. Biophys.

20: 315-319.

Mom č ilovi ć , B.; Kostial, K. (1974) Kinetics of lead retention and distribution in suckling and adult rats. Environ.

Res. 8: 214-220.
Moore, J. F.; Goyer, R. A. (1974) Lead-induced inclusion bodies: composition and probable role in lead metabolism. Environ. Health Perspect. 7: 121-127.

Mo ore, J. F.; Goyer, R. A.; Wilson, M. (1973) Lead-induced inclusion bodies: solubility, amino acid content, and relationship to residual acidic nuclear proteins. Lab. Invest. 29: 488-494.

# AX5-218 Moorman, W. J.; Skaggs, S. R.; Clark, J. C.; Turner, T. W.; Sharpnack, D. D.; Murre ll, J. A.; Simon, S. D.;
Chapin, R. E.; Schrader, S. M. (1998) Male reproductiv e effects of lead, including species extrapolation for the rabbit model. Reprod. Toxicol. 12: 333-346.
Moreira, E. G.; Vassilieff, I.; Vassilieff, V. S. (2001) De velopmental lead exposure: behavioral alterations in the
short and long term Neurotoxicol. Teratol. 23: 489-495. Morgan, R. E.; Levitsky, D. A.; Strupp, B. J. (2000) Effects of chronic lead exposure on learning and reaction time

in a visual discrimination task. Neurotoxicol Teratol. 22: 337-345.
Morgan, R. E.; Garavan, H.; Smith, E. G.; Driscoll, L. L.; Le vitsky, D. A.; Strupp, B. J. (2001) Early lead exposure produces lasting changes in sustained attention, resp onse initiation, and reactivity to errors. Neurotoxicol.

Teratol. 23: 519-531.

Morita, Y.; Sakai, T.; Araki, S.; Ar aki, T.; Masuyama, Y. (1997) Nicotin amide adenine dinucleotide synthetase activity in erythrocytes as a tool for the biological monitoring of lead exposure. Int. Arch. Occup. Environ.

Health 70: 195-198. Morley, E. J.; Hirsch, H. V.; Hollocher, K.; Lnenicka, G. A. (2003) Effects of chr onic lead exposure on the
neuromuscular junction in Drosophila larvae. Neurotoxicology 24: 35-41.
Moser, R.; Oberley, T. D.; Daggett, D. A.; Friedman, A. L.; Johnson, J. A.; Si egel, F. L. (1995) Effects of lead administration on developing rat kidney: I. Glutathione S-transferase isoenzymes. Toxicol. Appl.

Pharmacol. 131: 85-93.
Mousa, H. M.; Al-Qarawi, A. A.; Ali, B. H.; Abdel Rahman, H. A.; ElMougy, S. A. (2002) Effect of lead exposure on the erythrocytic antioxidant levels in goats. J. Vet. Med. A Physiol. Pathol. Clin. Med. 49: 531-534.
Mouw, D. R.; Vander, A. J.; Cox, J.; Fleischer, N. (1978) Acute effects of lead on renal electrolyte excretion and
plasma renin activity. Toxicol. Appl. Pharmacol. 46: 435-447. Mudzinski, S. P.; Rudofsky, U. H.; Mitchell, D. G.; La wrence, D. A. (1986) Anal ysis of lead effects on in vivo antibody-mediated immunity in several mouse st rains. Toxicol. Appl. Pharmacol. 83: 321-330.

Muller, S.; Gillert, K.-E.; Kr ause, C.; Gross, U.; L'Age-Stehr, J.; Diaman tstein, T. (1977) Suppression of delayed type hypersensitivity of mice by lead. Experientia 33: 667-668.
Munoz, C.; Garbe, K.; Lilienthal, H.; Winneke, G. (1986) Persistence of retention deficit in rats after neonatal lead
exposure. Neurotoxicology 7: 569-580.

Munoz, C.; Garbe, K.; Lilienthal, H.; Winneke, G. (1988) Significance of hippocampal dysfunction in low level lead
exposure of rats. Neurotoxicol. Teratol. 10: 243-253.

Munoz, C.; Garbe, K.; Lilienthal, H. ; Winneke, G. (1989) Neuronal depl etion of the amygdala resembles the learning deficits induced by low level lead expos ure in rats. Neurotoxicol. Teratol. 11: 257-264.
Muñoz, J. J.; Roca, C.; Santos, J. L.; Arroyo, M.; de Sala manca, R. E. (1993) Effectof zinc or S-adenosyl-lmethionine on long term administration of low doses of lead to rats. Pharmacol. Toxicol. (Copenhagen)

73: 189-191. Murphy, K.J.; Regan, C. M. (1999) Low-level lead exposu re in the early postnatal period results in persisting neuroplastic deficits associated with memory consolidation. J. Neurochem. 72: 2099-2104.
Murthy, R. C.; Saxena, D. K.; Gupta, S. K.; Chandra, S. V. (1991) Lead induced ultrastructural changes in the testis
of rats. Exp. Pathol. 42: 95-100. Murthy, R. C.; Gupta, S. K.; Saxena, D. K. (1995) Nuclear alterations during acrosomal cap formation in spermatids
of lead-treated rats. Reprod. Toxicol. 9: 483-489.

Naarala, J. T.; Loikkanen, J. J.; Ruot salainen, M. H.; Savolainen, K. M. (1 995) Lead amplifies glutamate-induced

oxidative stress. Free Radical Biol. Med. 19: 689-693.
Nakagawa, K. (1991) Decreased glutathione S -transferase activity in mice liver s by acute treatment with lead,
independent of alteration in glutathione content. Toxicol. Lett. 56: 13-17. Nakajima, T.; Deguchi, T.; Kagawa, K.; Hikita, H.; Ue da, K.; Katagishi, T.; Ohkawara, T.; Kakusui, M.;
Kimura, H.; Okanoue, T.; Kashima, K.; Ashihara, T. (1995) Identification of apoptotic hepatocytes in situ in

rat liver after lead nitrate administration. J. Gastroenterol. 30: 725-730. Nathan, E.; Huang, H. F. S.; Pogach, L.; Giglio, W.; Bogden, J. D.; Seebode, J. (1992) Lead acetate does not impair
secretion of Sertoli cell function marker proteins in the adult Sprague Dawley ra t. Arch. Environ. Health

47: 370-375. Nation, J. R.; Frye, G. D.; Von Stultz, J.; Bratton, G. R. (1989) Effects of combined lead and cadmium exposure:
changes in schedule-controlled responding and in d opamine, serotonin, and their metabolites. Behav.

Neurosci. 103: 1108-1114.

Natio n, J. R.; Livermore, C. L.; Burkey, R. T. (1996) Chronic lead exposure attenuates sensitization to the
locomotor-stimulating effects of cocaine. Drug Alcohol Depend. 41: 143-149.

# AX5-219 Nation, J. R.; Cardon, A. L.; Heard, H. M.; Valles, R.; Bratton, G. R. (2003) Perinatal lead exposure and relapse to
drug-seeking behavior in the rat: a cocaine reinstatement study. Psychopharmacology (Berl). 168:236-243. Nation, J. R.; Smith, K. R.; Bratton, G. R. (2004) Early developmental lead exposure increases sensitivity to cocaine
in a self-administration paradigm. Pharmacol. Biochem. Behav. 77: 127-135.
Nayak, B. N.; Ray, M.; Persaud, T. V. N.; Nigli, M. (1989a) Relationship of embryotoxicity to genotoxicity of lead nitrate in mice. Exp. Pathol. 36: 65-73.
Nayak, B. N.; Ray, M.; Persaud, T. V. N. (1989b) Maternal and fetal chromosomal aberrations in mice following
prenatal exposure to subembryotoxic doses of lead nitrate. Acta Anat. 135: 185-188. Neal, R.; Yang, P.; Fiechtl, J.; Yildiz, D.; Gurer, H.; Ercal, N. (1997) Pro-oxidant effects of δ -aminolevulinic acid
( δ -ALA) on Chinese hamster ovary (CHO ) cells. Toxicol. Lett. 91: 169-178.
Nehez, M.; Lorencz, R.; Desi, I. (2000) Simultaneous action of cypermethrin and two environmental pollutant

metals, cadmium and lead, on bone marrow cell chromosomes of rats in subchronic administration.

Ecotoxicol. Environ. Saf. 45: 55-60. Nehru, B.; Kaushal, S. (1992) Effect of lead on hepatic microsomal enzyme activity. J. Appl. Toxicol. 12: 401-405.
Neilan, B. A.; Taddeini, L.; McJilton, C. E.; Handwerger, B. S. (1980) Decreased T cell function in mice exposed to
chronic, low levels of lead. Clin. Exp. Immunol. 39: 746-749. Neilan, B. A.; O'Neill, K.; Handwerger, B. S. (1983) Effect of low-level lead exposure on antibody-dependent and
natural killer cell-mediated cytotoxicity. Toxicol. Appl. Pharmacol. 69: 272-275.

Nelson, B. K.; Moorman, W. J.; Schrader, S. M.; Shaw, P. B.; Krieg, E. F., Jr. (1997) Paternal exposure of rabbits to lead: behavioral deficits in offspring. Neurotoxicol. Teratol. 19: 191-198.
Nemoto, K.; Miyata, S.; Nemoto, F.; Yasumoto, T.; Murai, U.; Kageyama, H.; Degawa, M. (2000) Gene expression
of neutrophins and their receptors in lead nitrate-induced rat liver hyperplasia. Biochem. Biophys. Res.

Commun. 275: 472-476. Newland, M. C.; Yezhou, S.; Lögdberg, B.; Berlin, M. (1994) Prolonged behavioral effects of in utero exposure to lead or methyl mercury: reduced sensitivity to changes in reinforcement contingencies during behavioral transitions and in steady state. Toxicol. Appl. Pharmacol. 126: 6-15.
Newland, M. C.; Yezhou, S.; Lödgberg, B.; Berlin, M. (1996) In utero lead exposure in squirrel monkeys: motor

effects seen with schedule-controlled behavior. Neurotoxicol. Teratol. 18: 33-40. Ni, Z.; Hou, S.; Barton, C. H.; Vaziri, N. D. (2004) Lead exposure raises superoxide and hydrogen peroxide in
human endothelial and vascular smooth muscle cells. Kidney Int. 66: 2329-2336.
Nihei, M. K.; Guilarte, T. R. (1999) NMDAR-2A subunit protein expression is reduced in the hippocampus of rats exposed to Pb2+ during development. Mol. Brain Res. 66: 42-49.

Nihei, M. K.; Desmond, N. L.; McGlothan, J. L.; Kuhlmann, A. C.; Guilarte, T. R. (2000) N -methyl- D 

# -aspartate receptor subunit changes are associat ed with lead-induced deficits of long-term potentiation and spatial
learning. Neuroscience 99: 233-242.
Nikolova, P.; Kavaldzhieva, B. (1991) The effect of certain heavy metals (Mn and Pb) on parameters of erythrocyte energy metabolism. J. Hyg. Epidemiol. Microbiol. Immunol. 35: 361-365.
Nilsson, B. O.; Ljung, L.; Wide, M. (1991) Electron microscopy and X-ray microanalyses of uterine epithelium
from lead-injected mice in an experimental delay of implantation. Arch. Toxicol. 65: 239-243. Nolan, C. V.; Shaikh, Z. A. (1992) Lead nephrotoxic ity and associated disorders: biochemical mechanisms.
Toxicology 73: 127-146.
Novak, J.; Banks, R. O. (1995) Lead and nickel alter the ca rdiorenal actions of endothelin in the rat. Proc. Soc. Exp.

Biol. Med. 208: 191-198.
Oberley, T. D.; Friedman, A. L.; Moser, R.; Siegel, F. L. (1995) Effects of lead administration on developing rat
kidney. II. functional, morphologic, and immunohistochemical studies. Toxicol. Appl. Pharmacol.

131: 94-107. Odenbro, A.; Arrhenius, E. (1984) Effects of triethyllead chloride on hepatic microsomal N- and C-oxygenation of

N,N -dimethylaniline in rats. Toxicol. Appl. Pharmacol. 74: 357-363. Odenbro, A.; Kihlström, J. E. (1977) Frequency of pregnancy and ova implantation in triethyl lead-treated mice.
Toxicol. Appl. Pharmacol. 39: 359-363.
Odenbro, A.; Rafter, J. (1988) Effects of triethyl lead chloride on oestradiol metabolism in the female rat liver microsomal fraction. Pharmacol. Toxicol. (Copenhagen) 63: 248-52.
Odenbro, A.; Kihlström, I.; Kihlström, J. E. (1988) Perinatal growth retardation caused by triethyl lead chloride treatment of mice during late gestation. Ph armacol. Toxicol. (C openhagen) 63: 253-256.
O'Flaherty, E. J.; Hammond, P. B.; Lerner, S. I. (1982) Dependence of apparent blood lead half-life on the length of
previous lead exposure in humans. Fundam. Appl. Toxicol. 2: 49-54.

# AX5-220 O'Flaherty, E. J.; Inskip, M. J.; Frank lin, C. A.; Durbin, P. W.; Manton, W. I.; Baccanale, C. L. (1998) Evaluation
and modification of a physiologically based model of lead kinetics using data from a sequential isotope study in cynomolgus monkeys. Toxico l. Appl. Pharmacol. 149: 1-16.
Oishi, H.; Nakashima, M.; Totoki, T.; Tomokuni, K. (1996) Chronic lead exposure may inhibit endotheliumdependent hyperpolarizing factor in rats. J. Cardiovasc. Pharmacol. 28: 558-563. Olivi, L.; Cascio, S.; Wang, S.; Bressler , J. (2002) Mobilization of intracellular calcium in kidney epithelial cells is
inhibited by lead. Toxicology 176: 1-9.
Olshan, A. F.; Breslow, N. E.; Daling, J. R.; Falletta, J. M.; Grufferman, S.; Robiso n, L. L.; Waskerwitz, M.; Hammond, G. D. (1990) Wilms' tumor and paternal occupation. Cancer Res. 50: 3212-3217.
Ong, C. N.; Lee, W. R. (1980) Distribution of lead-203 in human peripheral blood in vitro . Br. J. Ind. Med.

37: 78-84. Oomen, A. G.; Tolls, J.; Sips, A. J.; Groten, J. P. (2003) In vitro intestinal lead uptake and transport in relation to
speciation. Arch. Environ. Contam. Toxicol. 44: 116-124. Oskarsson, A.; Fowler, B. A. (1985) Effects of lead inclusion bodies on subcellular distribution of lead in rat kidney:
the relationship to mitochondrial function. Exp. Mol. Pathol. 43: 397-408.
Oskarsson, A.; Hellström-Lindahl, E. (1989) Lead-dithiocarbama te interaction. Effect on ALAD activity in isolated rat hepatocytes. Biol. Trace Elem. Res. 21: 325-330.
Oskarsson, A.; Squibb, K. S.; Fowler, B. A. (1982) Intracellu lar binding of lead in the kidney: the partial isolation
and characterization of postmitochondrial lead binding components. Biochem. Biophys. Res. Commun.

104: 290-298. Osterode, W.; Ulberth, F. (2000) Increased concentration of arachidonic acid in erythrocyte membranes in
chronically lead-exposed men. J. Toxicol. Environ. Health A 59: 87-95. Othman, A. I.; El Missiry, M. A. (1998) Role of selenium against lead toxicity in male rats. J. Biochem. Mol.

Toxicol. 12: 345-349.
Otto, D. A.; Fox, D. A. (1993) Auditory and visual dysfunction following lead exposure. Neurotoxicology

14: 191-207.

Pace, B. M.; Lawrence, D. A.; Behr, M. J.; Parsons, P. J.; Dias, J. A. (2005) Neonatal lead exposure changes quality
of sperm and number of macrophages in testes of BALB/c mice. Toxicology 210: 247-256. Pagliara, P.; Carlà, E. C.; Caforio, S.; Chionna, A.; Mass a, S.; Abbro, L.; Dini, L. (2003a) Kupffer cells promote
lead nitrate-induced hepatocyte apoptosis via oxidative stress. Comp. Hepatol. 2: 8-21.
Pagliara, P.; Chionna, A.; Carlà, E. C.; Caforio, S.; Dini, L. (2003b) Lead nitrate and gadolinium chloride administration modify hepatocyte cell surfaces. Cell Tissue Res. 312: 41-48.
Palminger Hallén, I.; Jonsson, S.; Karlsson, M. O.; Oskarsson, A. (1996) Kinetic observations in neonatal mice exposed to lead via milk. Toxicol. Appl. Pharmacol. 140: 13-18.
Palus, J.; Rydzynski, K.; Dziubaltowska, E.; Wyszynska, K.; Natarajan, A. T.; Nilsson, R. (2003) Genotoxic effects
of occupational exposure to lead and cadmium. Mutat. Res. 540: 19-28. Pande, M.; Flora, S. J. (2002) Lead induced oxidative damage and its response to combined administration of

α -lipoic acid and succimers in rats. Toxicology 177: 187-196.
Pande, M.; Mehta, A.; Pant, B. P.; Flora, S. J. S. ( 2001) Combined administration of a chelating agent and an antioxidant in the prevention and treatment of acute lead intoxication in rats. Environ. Toxicol. Pharmacol.

9: 173-184. Panemangalore, M.; Bebe, F. N. (1996) Effects of low oral lead and cadmium exposure and zinc status on heme metabolites in weanling rats. Int. J. Occu p. Med. Environ. Health 9: 141-151.

Pani, P.; Dessi, S.; Rao, K. N.; Batetta, B.; Laconi, E. (1984) Changes in serum and hepatic cholesterol in
lead-induced liver hyperplasia. Toxicol. Pathol. 12: 162-167. Papaioannou, N.; Vlemmas, I.; Balaskas, N.; Tsangaris, T. (1998) Histopathological lesions in lead intoxicated dogs.

Vet. Hum. Toxicol. 40: 203-207.
Pappas, J. B.; Ahlquist, J. T.; Allen, E. M.; Banner, W., Jr. (1995) Oral dimercaptosuccinic acid and ongoing exposure to lead: effects on heme synthesis and lead distribution in a rat model. Toxicol. Appl. Pharmacol.

133: 121-129. Patierno, S. R.; Landolph, J. R. (1989) Soluble vs insoluble hexavalent chromate. Relationship of mutation to

in vitro transformation and particle uptake. Biol. Trace Elem. Res. 21: 469-474.
Patierno, S. R.; Banh, D.; Landolph, J. R. (1988) Transformation of C3H/10T1/2 mouse embryo cells to focus formation and anchorage independence by insoluble lead chromate but not soluble calcium chromate:
relationship to mutagenesis and internalization of lead chromate particles. Cancer Res. 48: 5280-5288.

# AX5-221 Patra, R. C.; Swarup, D. (2000) Effect of lead on erythr ocytic antioxidant defence, lipid peroxide level and thiol
groups in calves. Res. Vet. Sci. 68: 71-74. Patra, R. C.; Swarup, D.; Dwivedi, S. K. (2001) Antioxidant effects of α tocopherol, ascorbic acid and L-thenionine
on lead induced oxidative stress to the liver, kidney and brain in rats. Toxicology 162: 81-88.
Payton, M.; Riggs, K. M.; Spiro, A., III; Weiss, S. T.; Hu , H. (1998) Relations of bone and blood lead to cognitive function: the VA Normative Aging Study. Neurotoxicol. Teratol. 20: 19-27.

Peixoto, N. C.; Roza, T.; Pereir a, M. E. (2004) Sensitivity of δ -ALA-D (E.C. 4.2.1.24) of rats to metals in vitro
depends on the stage of postnatal growth and tissue. Toxicol. in Vitro 18: 805-809. Pentschew, A.; Garro, F. (1966) Lead encephalo-myelopathy of the suckling rat and its implications on the
porphyrinopathic nervous diseases, with special reference to the permeability disorders of the nervous
system's capillaries. Acta Neuropathol. 6: 266-278.
Pereira, B.; Curi, R.; Kokubun, E.; Bechara, E. J. H. ( 1992) 5-aminolevulinic acid-induced alterations of oxidative
metabolism in sedentary and exercise-trained rats. J. Appl. Physiol. 72: 226-230.

Perez-Bravo, F.; Ruz, M; Moran-Jimen ez, M. J.; Olivares, M.; Rebolledo, A.; Codoceo, J.; Sepulveda, J.; Jenkin, A.;
Santos, J. L.; Fontanellas, A. (2004) Association between aminolevulinate dehydrase genotypes and blood
lead levels in children from a lead-contaminated area in Antofagasta, Chile. Arch. Environ. Contam.

Toxicol. 47: 276-280.
Pergande, M.; Jung, K.; Precht, S.; Fels, L. M.; Herbort, C.; Stolte, H. (1994) Changed excretion of urinary proteins
and enzymes by chronic exposure to lead. Nephrol. Dial. Transplant. 9: 613-618. Piasecka, M.; Rózewicka, L.; Laszczy ń ska, M.; Marchlewicz, M. (1995) Electro n-dense deposits in epididymal cells
of rats chronically treated with lead acetate [P b(II)]. Folia Histochem. Cytobiol. 33: 89-94.
Piasek, M.; Kostial, K. (1991) Reversib ility of the effects of lead on the re productive performance of female rats. Reprod. Toxicol. 5: 45-51.
Piccinini, F.; Favalli, L.; Chiari, M. C. (1977) Experiment al investigations on the conctraction induced by lead in
arterial smooth muscle. Toxicology 8: 43-51. Pillai, A.; Gupta, S. (2005) Effect of gestational and l actational exposure to lead and/or cadmium on reproductive
performance and hepatic oestradiol metabolising enzymes. Toxicol. Lett. 155: 179-186.
Pineda-Zavaleta, A. P.; García-Vargas, G.; Borja-Abur to, V. H.; Acosta-Saavedea, L. C.; Vera Aguilar, E.; Gómez-Muñoz, A.; Cebrián, M. E. Calderón-Aranda, E. S. (2004) Nitric oxide and superoxide anion
production in monocytes from children exposed to arsenic and lead in region Lagunera, Mexico. Toxicol.
Appl. Pharmacol. 198: 283-290. Pinkerton, L. E.; Biagini, R. E.; Ward, E. M.; Hull, R. D.; Deddens, J. A.; Boenig er, M. F.; Schnorr, T. M.;

MacKenzie, B. A.; Luster, M. I. (1998) Immunologic findings among lead-exposed workers. Am. J. Ind.

Med. 33: 400-408.
Pinon-Lataillade, G.; Thoreux-Manlay, A.; Coffigny, H.; M onchaux, G.; Masse, R.; Soufir, J.-C. (1993) Effect of
ingestion and inhalation of lead on the reproductive syst em and fertility of adult male rats and their progeny. Hum. Exp. Toxicol. 12: 165-172.
Pinon-Lataillade, G.; Thoreux-Manlay, A.; Coffigny, H.; Masse , R.; Soufir, J. C. (1995) Reproductive toxicity of
chronic lead exposure in male and female mice. Hum. Exp. Toxicol. 14: 872-878.

Pinto, D.; Ceballos, J. M.; Garcia, G.; Guzman, P.; Del Razo, L. M.; Vera, E.; Gomez, H.; Garcia, A.;
Gonsebatt, M. E. (2000) Increased cytogenetic damage in outdoor painters. Mutat. Res. 467: 105-111.
Pirkle, J. L.; Schwartz, J.; Landis, J. R.; Harlan, W. R. (1985) The relationship between blood lead levels and blood pressure and its cardiovascular risk implications. Am. J. Epidemiol. 121: 246-258.
Planas-Bohne, F.; Elizalde, M. (1992) Activity of glut athione-S-transferase in ra t liver and kidneys after

administration of lead or cadmium. Arch. Toxicol. 66: 365-367. Polizopoulou, Z. S.; Kontos, V. S.; Koutinas, A. F.; Papasteriades, A. (1994) Whole blood lead concentration and
erythrocyte delta-aminolevulinic acid dehydratase (ALAD) activity in selected canine populations in
Greece. J. Trace Elem. Electroly tes Health Dis. 8: 203-207.
Pounds, J. G.; Rosen, J. F. (1986) Cellular metabolism of l ead: a kinetic analysis in cultured osteoclastic bone cells.
Toxicol. Appl. Pharmacol. 83: 531-545.
Pounds, J. G.; Long, G. J.; Rosen, J. F. (1991) Cellular and molecular toxicity of lead in bone. Environ. Health
Perspect. 91: 17-32. Prentice, R. C.; Kopp, S. J. (1985) Cardiotoxicity of lead at various perfusate calcium concentrations: functional and metabolic responses of the perfused rat heart. Toxicol. Appl. Pharmacol. 81: 491-501.
Price, R. G. (2000) Urinalysis to exclude and monitor nephrotoxicity. Clin. Chim. Acta 297: 173-182.

# AX5-222 Price, R. G.; Taylor, S. A.; Chivers, I.; Arce-Tomas, M.; Crutcher, E.; Fran chini, I.; Slinovi, R.; Cavazzini, S.;
Bergamaschi, E.; Mutti, A.; Vettori, M. V.; Lauwerys, R.; Bernard, A.; Ka banda, A.; Roels, H.; Thielemans, N.; Hotz, P.; De Broe, M. E.; Elseviers, M. M.; Nuyts, G. D.; Gelpi, E.; Hotter, G.; Rosello, J.; Ramis, I.;
Stolte, H.; Fels, L. M.; Eisenberger, U. (1996) De velopment and validation of new screening tests for
nephrotoxic effects. Hum. Exp. Toxicol. 15(suppl. 1): S10-S19. Prigge, E.; Greve, J. (1977) Effekte einer Bleiinhala tion allein und in Kombination mit Kohlenmonoxid bei
nichttragenden und tragenden Ratten und deren Feten. II. Effekte auf die Aktivitat der δ -AminolavulinsaureDehydratase, den Hematokrit und das Korpergewicht [Effects of lead inhaltion exposures alone and in combination with carbon monoxide in nonpregnant and pregnant rats and fetuses. II. Effects on δ

aminolevulinic acid dehydratase activity, hematocrit and body weight. Zentralbl. Bakteriol. Parasitenkd.
Infektionskrankh. Hyg. 16: 294-304. Priya, P. N.; Pillai, A.; Gupta, S. (2004) Effect of simultaneous exposure to lead and cadmium on gonadotropin
binding and steroidogenesis on granulosa cells: an in vitro study. Indian J. Exp. Biol. 42: 143-148. Purdy, R. E.; Smith, J. R.; Ding, Y.; Oveisi, F.; Varizi, N. D.; Gonick, H. C. (1997) Lead-induced hypertension is
not associated with altered vascular reactivity in vitro. Am. J. Hypertens. 10: 997-1003.
Pyatt, D. W.; Zheng, J.-H.; Stillman, W. S.; Irons, R. D. (199 6) Inorganic lead activates NF-kB in primary human CD4+ T lymphocytes. Biochem. Biophys. Res. Commun. 227: 380-385.
Qian, Z. M.; Morgan, E. H. (1 990) Effect of lead on the transport of transferrin-free and transferrin-bound iron into
rabbit reticulocytes. Biochem. Pharmacol. 40: 1049-1054. Qian, Y.; Harris, E. D.; Zheng, Y.; Ti ffany-Castiglioni, E. (2000) Lead target s GRP78, a molecular chaperone, in
C6 rat glioma cells. Toxicol. Appl. Pharmacol.163: 260-266.
Qian, Y., Zheng, Y., Ramos, K. S.; Tiffany-Castiglioni , E. (2005a) GRP78 compartmentalized redistribution in Pb-treated glia: role of GRP78 in lead-induced oxidative stress. Neurotoxicology. 26: 267-275.
Qian, Y.; Zheng, Y.; Ramos, K. S.; Tiffany-Castiglioni, E. (2005b) The in volvement of copper transporter in
lead-induced oxidative stress in astroglia. Neurochem. Res. 30: 429-438. Qu, W.; Diwan, B. A.; Liu, J.; Goyer, R. A.; Dawson, T.; Horton, J. L.; Cherian, M. G.; Waalkes, M. P. (2002) The
metallothionein-null phenotype is associated with heightened sensitivity to lead toxicity and an inability to

form inclusion bodies. Am. J. Pathol. 160: 1047-1056.
Queiroz, M. L. S.; Almeida, M.; Gallão, M. I.; Höehr, N. F. (1993) Defective neutrophil function in workers
occupationally exposed to lead. Pharmacol. Toxicol. 72: 73-77.
Queiroz, M. L. S.; Perlingeiro, R. C. R.; Bincoletto, C.; Almeida, M.; Car doso, M. P.; Dantas, D. C. M. (1994) Immunoglobulin levels and cellular immune function in lead exposed workers. Immunopharmacol.

Immunotoxicol. 16: 115-128.
Quinlan, G. J.; Halliwell, B. ; Moorhouse, C. P.; Gutteridge, J. M. (1988) Action of lead(I I) and aluminium(III) ions
on iron-stimulated lipid peroxidation in liposomes, erythrocytes and rat liver microsomal fractions.
Biochim. Biophys. Acta. 962: 196-200.
Quinn, M. R.; Harris, C. L. (1995) Lead inhibits Ca2+-s timulated nitric oxide synthase activity from rat cerebellum.

Neurosci. Lett. 196: 65-68.
Quintanilla-Vega, B.; Smith, D. R.; Kahng, M. W.; Hernán dez, J. M.; Albores, A.; Fo wler, B. A. (1995) Leadbinding proteins in brain tissue of environmentally lead-exposed humans. Chem. Biol. Interact. 98: 193-209.
Quintanilla-Vega, B.; Hoover, D. J.; Bal, W.; Sibergeld, E. K., Waalkes, M. P., Anderson, L. D. (2000) Lead
interaction with human protamine (HP2 ) as a mechanism of male reproduc tive toxicity. Chem. Res. Toxicol.

13: 594-600. Raghavan, S. R. V.; Gonick, H. C. (1977) Isolation of low-molecular-weight lead-binding protein from human
erythrocytes. Proc. Soc. Exp. Biol. Med. 155: 164-167. Raghavan, S. R. V.; Culver, B. D.; Gonick, H. C. (1980) Erythrocyte lead-binding protein after occupational
exposure. I. Relationship to lead to xicity. Environ. Res. 22: 264-270.
Raghavan, S. R. V.; Culver, B. D.; Gonick, H. C. (1981) Erythrocyte lead-binding protein after occupational exposure. II. influence on lead inhibition of membrane Na+, K+ - adenosinetrip hosphatase. J. Toxicol.

Environ. Health 7: 561-568.
Rajah, T. T.; Ahuja, Y. R. (1995) In vivo genotoxic effects of smoking and occupational lead exposure in printing press workers. Toxicol. Lett. 76: 71-75.
Rajah, T. T.; Ahuja, Y. R. (1996) In vivo genotoxicity of alcohol consumption and lead exposure in printing press

workers. Alcohol 13: 65-68.

# AX5-223 Ramesh, G. T.; Manna, S. K.; Aggarwal, B. B.; Jadhav, A. L. (1999) Lead activ ates nuclear transcription factor -kB,
activator protein-1, and amino-termin al c-Jun kinase in pheochromocytoma cells. Toxicol. Appl. Pharmacol.

155: 280-286. Ramesh, G. T.; Manna, S. K.; Aggarwal, B. B.; Jadhav, A. L. (2001) Lead ex posure activates nuclear factor kappa
B, activator protein-1, c-Jun N-terminal kinase and caspases in the rat brain. Toxicol. Lett. 123: 195-207 Razani-Boroujerdi, S.; Edwards, B.; Sopori, M. L. (1999) Lead stimulat es lymphocyte proliferation through

enhanced T cell-B cell interaction. J. Ph armacol. Exp. Therap. 288: 714-719.
Redig, P. T.; Lawler, E. M.; Schwartz, S.; Dunnette, J. L.; Stephenson, B.; Duke, G. E. (1991) Effects of chronic exposure to sublethal concentrations of lead acetate on heme synthesis and imm une function in red-tailed

hawks. Arch. Environ. Contam. Toxicol. 21: 72-77.
Reigart, J. R.; Graber, C. D. (1976) Evaluation of the humoral immune response of children with low level lead exposure. Bull. Environ. Contam. Toxicol. 16: 112-117.
Restrepo, H. G.; Sicard, D.; Torres, M. M. (2000) DNA damage and repair in cells of lead exposed people. Am.

J. Ind. Med. 38: 330-334.

Reuhl, K. R.; Rice, D. C.; Gilbert, S. G.; Mallett, J. (1989) Effects of chronic developmental lead exposure on
monkey neuroanatomy: visual system. Toxicol. Appl. Pharmacol. 99: 501-509.
Revis, N. W.; Zinsmeister, A. R.; Bull, R. (1981) Athero sclerosis and hypertension induction by lead and cadmium
ions: an effect prevented by calcium ion. Pr oc. Natl. Acad. Sci. U. S. A. 78: 6494-6498.
Reyes, A.; Mercado, E.; Goicoechea, B.; Rosado, A. (1976) Participation of membrane sulfhydryl groups in the epididymal maturation of human and rabbit sp ermatozoa. Fertil. St eril. 27: 1452-1458.
Rice, D. C. (1988a) Chronic low-level exposure in monkey s does not affect simple r eaction time. Neurotoxicology

9: 105-108. Rice, D. C. (1988b) Schedule-controlled behavior in infant and juvenile monkeys exposed to lead from birth.
Neurotoxicology 9: 75-88.
Rice, D. C. (1990) Lead-induced behavioral impairment on a spatial discrimination reversal task in monkeys exposed during different periods of development. Toxicol. Appl. Pharmacol. 106: 327-333.
Rice, D. C. (1992a) Lead exposure during different developmental periods produces different effects on FI
performance in monkeys tested as juveniles and adults. Neurotoxicology 13: 757-770. Rice, D. C. (1992b) Behavioral effects of lead in monkeys tested during infancy and adulthood. Neurotoxicol.

Teratol. 14: 235-245.
Rice, D. C. (1992c) Effect of lead during different developmental periods in the monkey on concurrent discrimination performance. Neurotoxicology 13: 583-592.
Rice, D. C. (1997) Effects of lifetime lead exposure in monkeys on detection of pure tones. Fundam. Appl. Toxicol.

36: 112-118. Rice, D. C.; Gilbert, S. G. (1990a) Lack of sensitive pe riod for lead-induced behavioral impairment on a spatial
delayed alternation task in monkeys. Toxicol. Appl. Pharmacol. 103: 364-373. Rice, D. C.; Gilbert, S. G. (1990b) Sensitive periods for lead-induced behavioral impairment (nonspatial
discrimination reversal) in monkeys. Toxicol. Appl. Pharmacol. 102: 101-109.
Rice, D. C.; Hayward, S. (1999) Comparison of visual function at adulthood and during aging in monkeys exposed to lead or methylmercury. Neurotoxicology 20: 767-784.
Rice, D. C.; Karpinski, K. F. (1988) Lifetime low-level lead exposure produces deficits in delayed alternation in
adult monkeys. Neurotoxicol. Teratol. 10: 207-214. Rice, D. C.; Gilbert, S. G.; Willes, R. F. (1979) Neonatal low-level lead exposure in monkeys: locomotor activity,
schedule-controlled behavior, and the effects of amphetamine. Toxicol. Appl. Pharmacol. 51: 503-513.

Richardt, G.; Federolf, G.; Habermann, E. (1986) Affinity of heavy metal ions to intracellular Ca2+-binding proteins. Biochem. Pharmacol. 35: 1331-1335.
Rijhsinghani, K.; Choi, H.-S. H.; Burton, L. A.; Paronetto, F.; Tavoloni, N. (1993) Immunoelectron microscopy
identification of early proliferating cells in rat liver tissue during hyperplasia induced by lead nitrate. Hepatology (Baltimore) 17: 685-692.

Rizzi, C. A.; Manzo, L.; Tonini, M.; Minoia, C.; Crema, A. (1989) Propulsive motility of the guinea-pig colon after

chronic lead treatment. Phar macol. Res. 21: 127-128. Roberts, J. R.; Reigart, J. R.; Ebeling, M.; Hulsey, T. C. (2001) Time required for blood lead levels to decline in

nonchelated children. Clin. Toxicol. 39: 153-160.

Rocha, A.; Valles, R.; Cardon, A. L.; Bratton, G. R.; Nation, J. R. (2005) Enhanced acquisition of cocaine selfadministration in rats developmentally exposed to lead. Neuropsychopharmacology 30: 2058-2064.

# AX5-224 Rodamilans, M.; Mtz.-Osaba, M. J.; To-Figueras, J.; Rivera -Fillat, F.; Torra, M.; Perez, P.; Corbella, J. (1988)
Inhibition of intratesticular testosterone synthesi s by inorganic lead. Toxicol. Lett. 42: 285-290. Rodrigues, A. L.; Rocha, J. B.; Mello, C. F.; Souza, D. O. (1996a) Effect of perinatal lead exposure on rat behaviour
in open-field and two-way avoidance ta sks. Pharmacol. Toxicol. 79: 150-156.
Rodrigues, A. L.; Rocha, J. B.; Pere ira, M. E.; Souza, D. O. (1996b) δ -aminolevulinic acid dehydratase activity in weanling and adult rats exposed to lead acetate. Bull. Environ. Contam. Toxicol. 57: 47-53.
Rodríguez-Iturbe, B.; Vaziri, N. D.; Herr era-Acosta, J.; Johnson, R. J. (2004) Oxidative stre ss, renal infiltration of
immune cells, and salt-sensitive hypertension: all for one and one for all. Am. J. Physiol. 286: F606-F616. Rodríguez-Iturbe, B.; Sindhu, R. K.; Quiroz, Y.; Vaziri, N. D. (2005) Chronic exposure to low doses of lead results

in renal infiltration of immune cells, NF- κ B activation, and overexpression of tubulointerstitial angiotensin
II. Antioxid. Redox Signaling 7: 1269-1274. Roels, H.; Lauwerys, R. ; Konings, J.; Buchet, J.-P.; Bernard, A.; Gr een, S.; Bradley, D.; Morgan, W.; Chettle, D.
(1994) Renal function and hyperfiltration capacity in lead smelter workers with high bone lead. Occup.

Environ. Med. 51: 505-512
Ronis, M. J. J.; Badger, T. M.; Shema, S. J.; Roberson, P. K.; Shaikh, F. (1996) Reproductive toxicity and growth
effects in rats exposed to lead at different periods during development. Toxicol. Appl. Pharmacol.

136: 361-371. Ronis, M. J.; Badger, T. M.; Shema, S. J.; Roberson, P. K.; Shaikh, F. (1998a) Effects on pubertal growth and
reproduction in rats exposed to lead perinatally or continuously throughout development. J. Toxicol.

Environ. Health A 53: 327-341.
Ronis, M. J. J.; Gandy, J.; Badger, T. (1998b) Endocrine mechanisms underl ying reproductive toxicity in the
developing rat chronically exposed to dietary lead. J. Toxicol. Environ. Health Part A 54: 77-99. Ronis, M. J. J.; Badger, T. M.; Shema, S. J.; Roberson, P. K.; Templer, L.; Ringer, D.; Thomas, P. E. (1998c)
Endocrine mechanisms underlying the growth effects of developmental lead exposure in the rat. J. Toxicol.

Environ. Health Part A 54: 101-120.

Ronis, M. J. J.; Aronson, J.; Gao, G. G.; Hogue, W.; Skinner, R. A.; Badger, T. M.; Lumpkin, C. K., Jr. (2001)
Skeletal effects of developmental lead expos ure in rats. Toxicol. Sci. 62: 321-329.

Roomi, M. W.; Columbano, A.; Ledda-Columbano, G. M.; Sarma, D. S. R. (1986) Lead nitrate induces certain biochemical properties characteristic of hepatocyte nodules. Carcinogenesis 7: 1643-1646.
Roomi, M. W.; Columbano, A.; Ledda-Columbano, G. M.; Sarma, D. S. R. (1987) Induction of the placental form
of glutathione S-transferase by lead nitrate admini stration in rat liver. Toxicol. Pathol. 15: 202-205. Rosen, J. F. (1983) The metabolism of lead in isolated bone cell populations: interactions between lead and calcium.
Toxicol. Appl. Pharmacol. 71: 101-112.
Rosen, J. F.; Markowitz, M. E. (1980) D-Penicillamine: its actions on lead transport in bone organ culture. Pediatr.

Res. 14: 330-335.

Rosen, J. F.; Pounds, J. G. (1988) The cellular metabolism of lead an d calcium: a kinetic analysis in cultured osteoclastic bone cells. In: De Broe, M. E.; Van de Vy ver, F. L., eds. Bone and renal failure: international
symposium; November 1986; Antwerp, Belgium. Basel, Switzerland: S. Karger; pp. 74-82. (Contributions
to nephrology: v. 64.)
Rosen, J. F.; Pounds, J. G. (1989) Quantitative inter actions between Pb2+ and Ca2+ homeostasis in cultured
osteoclastic bone cells. Toxicol. Appl. Pharmacol. 98: 530-543.
Rosen, J. F.; Wexler, E. E. (1977) Studies of lead transport in bone organ culture. Biochem. Pharmacol.

26: 650-652.

Rosen, J. F.; Kraner, H. W.; Jone s, K. W. (1982) Effects of CaNa 2 

# EDTA on lead and trace metal metabolism in
bone organ culture. Toxicol. Appl. Pharmacol. 64: 230-235. Rossi, E.; Attwood, P. V.; Garcia-Webb, P. (1992) Inhibition of human lymphocyte coproporphyrinogen oxidase
activity by metals, bilirubin and haemin . Biochim. Biophys. Acta 1135: 262-268.
Roy, N. K.; Rossman, T. G. (1992) Mutagenesis and comu tagenesis by lead compounds. Mutat. Res. 298: 97-103. Roy, A. K.; Dhir, H.; Sharma, A. (1992) Modification of metal-induced micronuclei formation in mouse bone
marrow erythrocytes by Phyllanthus fruit extract and ascorbic acid. Toxicol. Lett. 62: 9-17.
Ruan, D.-Y.; Chen, J.-T.; Zhao, C.; Xu, Y.-Z.; Wang, M. ; Zhao, W.-F. (1998) Impairment of long-term potentiation and paired-pulse facilitation in rat hippocampal dentate gyrus following developmental lead exposure in

vivo. Brain Res. 806: 196-201.

Ruzittu, M.; Carlá, E. C.; Mo ntinari, M. R.; Maietta, G.; Dini, L. (19 99) Modulation of cell surface expression of
liver carbohydrate receptors during in vivo induction of apoptosis w ith lead nitrate. Cell Tissue Res.

298: 105-112.

# AX5-225 Sabbioni, E.; Marafante, E. (1976) Identifica tion of lead-binding components in rat liver: in vivo study. Chem. Biol.

Interact. 15: 1-20. Salinas, J. A.; Huff, N. C. (2002) Lead and spatial vs. cued open field performance. Neurotoxicol. Teratol.

24: 551-557. Sánchez, S.; Aguilar R. P.; Genta, S.; Aybar, M.; Villecco, E.; Riera, A. S. (2001) Renal ex tracellular matrix alterations in lead-treated rats. J. Appl. Toxicol. 21: 417-423.
Sánchez-Fructuoso, A. I.; Blanco, J.; Cano, M.; Ortega, L. ; Arroyo, M.; Fernández, C.; Prats, D.; Barrientos, A.
(2002a) Experimental lead nephropathy: treatment with calcium di sodium ethylenediam inetetraacetate. Am. J. Kidney Dis. 40: 59-67.
Sánchez-Fructuoso, A. I.; Cano, M.; Arroyo, M.; Fernández, C.; Prats, D.; Barrientos, A. (2002b) Lead mobilization
during calcium disodium ethylenediaminetetraacetate chelation ther apy in treatment of chronic lead poisoning. Am. J. Kidney Dis. 40: 51-58.
Sandhir, R.; Gill, K. D. (1995) Effect of lead on lipid peroxidation in liver of rats. Biol. Trace Elem. Res. 48: 91-97. Sant'Ana, M. G.; Spinosa, H. S.; Florio, J. C.; Bernardi, M. M.; Oliveira, C. A.; Sarkis, J. E.; Kakazu, M. H. (2001)
Role of early GnRH administration in sexual behavior disorders of rat pups perinatally exposed to lead.

Neurotoxicol. Teratol. 23: 203-212. Santos, J. L.; Fontanellas, A.; Morán, M. J.; Enriquez de Salamanca, R. (1999) Nonsynergic effect of ethanol and

lead on heme metabolism in rats. Ecotoxicol. Environ. Saf. 43: 98-102.
Sarasua, S. M.; Vogt, R. F.; Henderson, L. O.; Jones, P. A.; Lybarger, J. A. (2000) Serum immunoglobulins and lymphocyte subset distributions in children and adults living in communities asse ssed for lead and cadmium
exposure. J. Toxicol. Environ. Health A. 60: 1-15.
Sata, F.; Araki, S.; Tanigawa, T.; Morita, Y.; Sakurai, S.; Nakata, A.; Katsuno, N. (1998) Changes in T cell subpopulations in lead workers. Environ. Res. 76: 61-64.
Satija, N. K.; Vij, A. G. (1995) Prev entive action of zinc against lead toxicity. Indian J. Physiol. Pharmacol.

39: 377-382. Sauk, J. J.; Smith, T.; Silbergeld, E. K.; Fowler, B. A.; Somerman, M. J. (1992) Lead inhibits secretion of
osteonectin/SPARC without significantly altering co llagen or Hsp47 production in osteoblast-like ROS
17/2.8 cells. Toxicol. Appl. Pharmacol. 116: 240-247. Saxena, G.; Flora, S. J. S. (2004) Lead-induced oxidative stress and hematological alterations and their response to

combined administration of calcium disodium EDTA with a thiol chelator in rats. J. Biochem. Mol. Toxicol.

18: 221-233. Saxena, D. K.; Lal, B.; Murthy, R. C.; Chandra, S. V. (1984) Lead induced histochemical changes in the testes of

rats. Ind. Health 22: 255-260.

Saxena, D. K.; Hussain, T.; Lal, B.; Chan dra, S. V. (1986) Lead induced testicular dysfunction in weaned rats. Ind.

Health 24: 105-109.
Saxena, D. K.; Srivastava, R. S.; Lal, B.; Chandra, S. V. (1987) The effect of lead exposure on the testis of growing rats. Exp. Pathol. 31: 249-252.

Saxena, D. K.; Lal, B.; Srivastava, R. S.; Chandra, S. V. (1990) Lead induced testicular hypersensitivity in stressed
rats. Exp. Pathol. 39: 103-109. Schanne, F. A. X.; Dowd, T. L.; Gupta, R. K.; Rosen, J. F. (1989) Lead increases free Ca2+ concentration in

cultured osteoblastic bone cells: simultaneous detection of intracellular free Pb2+ by 19F NMR. Proc. Natl.

Acad. Sci. U. S. A. 86: 5133-5135. Schanne, F. A. X.; Gupta, R. K.; Rosen, J. F. (1992) Lead inhibits 1,25-dihydroxyvitamin D-3 regulation of calcium
metabolism in osteoblastic osteosarcoma cells (R OS 17/2.8). Biochim. Bi ophys. Acta 1180: 187-194.
Schanne, F. A. X.; Long, G. J.; Rosen, J. F. (1997) Lead induced rise in intracellular free calcium is mediated through activation of protein kinase C in osteoblastic bone cells. Biochim. Biophys. Acta 1360: 247-254.

Schechtman, L. M.; Hatch, G. G.; Anderson, T. M.; Putman , D. L.; Kouri, R. E.; Came ron, J. W.; Nims, R. W.;
Spalding, J. W.; Tennant, R. W.; Lubet, R. A. (1986) Analysis of the interlab oratory and intralaboratory reproducibility of the enhancement of simian adenov irus SA7 transformation of Syrian hamster embryo
cells by model carcinogenic and noncarcinogenic compounds. Environ. Mutagen. 8: 495-514.
Scheuhammer, A. M. (1987) Erythrocyte δ -aminolevulinic acid dehydratase in birds. II. The effects of lead exposure in vivo. Toxicology 45: 165-175.
Schirrmacher, K.; Wiemann, M.; Bingmann, D.; Büsselber g, D. (1998) Effects of lead, mercury, and methyl mercury on gap junctions and [CA2+] i 

# in bone cells. Calcified Tiss. Int. 63: 134-139.
Schlick, E.; Friedberg, K. D. (1981) The influence of low lead doses on the reticulo-endothelial system and
leucocytes of mice. Arch. Toxicol. 47: 197-207.

# AX5-226 Schlipkoter, H.-W.; Frieler, L. (1979) Der Einfluss kurzze itiger Bleiexposition auf die Bakterienclearance der Lunge
[The influence of short-term lead exposure on the b acterial clearance of the lung ]. Zentralbl. Bakteriol. Parasitenkd. Infektionskr. Hyg. Abt. 1: Orig. Reihe B 168: 256-265.

Schmitt, C. J.; Caldwell, C. A.; Olsen, B.; Serdar , D.; Coffey, M. (2002) Inhibition of erythrocyte δ -aminolevulinic
acid dehydratase (ALAD) activity in fi sh from waters affected by lead smelters. Environ. Monit. Assess.

77: 99-119. Schneider, J. S.; Lee, M. H.; Anderson, D. W.; Zuck, L.; Lidsky, T. I. (2001) Enriched environment during
development is protective against lead-induced neurotoxicity. Brain Res. 896: 48-55. Schneider, J. S.; Anderson, D. W.; Wade, T. V.; Smith, M. G.; Leibrandt, P.; Zuck, L.; Lidsky, T. I. (2005)
Inhibition of progenitor cell proliferation in the dentate gyrus of rats following post-weaning lead exposure.
Neurotoxicology 26: 141-145. Schneyer, C. A.; Hall, H. D. (1970) Influence of physiol ogical activity on mitosis in immature rat parotid gland.
Proc. Soc. Exp. Biol. Med. 133: 349-352. Schrauzer, G. N. (1987) Effects of selenium antagon ists on cancer susceptibility: new aspects of chronic heavy
metal toxicity. J. UOEH 9 Suppl: 208-215.
Schroeder, H. A.; Mitchener, M. (1971) Toxic effects of trace elements on the reproduction of mice and rats. Arch.

Environ. Health 23: 102-106.

Schwartz, B. S.; Lee, B.-K.; Stewart, W.; Sithisar ankul, P.; Strickland, P. T.; Ahn, K.-D.; Kelsey, K. (1997a)

δ -Aminolevulinic acid dehydratase genotype modifies four hour urinary lead excretion after oral administration of dimercaptosuccinic acid. Occup. Environ. Med. 54: 241-246.

Schwartz, B. S.; Lee, B.-K.; Stewart, W.; Ahn, K.-D.; Kelsey, K.; Bresssler , J. (1997b) Associatio ns of subtypes of
hemoglobin with delta-aminolevulinic acid dehydratase genotype and dimercaptosuccinic acid-chelatable

lead levels. Arch. Environ. Health 52: 97-103.
Seaton, C. L.; Lasman, J.; Smith, D. R. (1999) The eff ects of CaNa2EDTA on brain lead mobilization in rodents
determined using a stable lead isotope trace r. Toxicol. Appl. Pharmacol. 159: 153-160. Selvin-Testa, A.; Lopez-Costa, J. J.; Nessi-de Avinon, A. C.; Saavedra, J. P. (1991) Astroglial alterations in rat
hippocampus during chronic lead exposure. Glia 4: 384-392.
Selye, H.; Tuchweber, B.; Bertók, L. (1966) Effect of lead acetate on th e susceptibility of rats to bacterial

endotoxins. J. Bacteriol. 91: 884-890.
Senapati, S. K.; Dey, S.; Dwivedi, S. K.; Patra, R. C.; Sw arup, D. (2000) Effect of thiamine hydrochloride on lead
induced lipid peroxidation in rat liver and kidney. Vet. Hum. Toxicol. 42: 236-237. Sengupta, M.; Bishayi, B. (2002) Effect of lead and ar senic on murine macrophage response. Drug Chem. Toxicol.

25: 459-472.
Serrani, R. E.; Gioia, I. A.; Corchs, J. L. (1997) Lead effects on structural and functional cellular parameters in
human red cells from a prenatal hematopoiesis stage. Biometals 10: 331-335.
Shabani, A.; Rabbani, A. (2000) Lead nitrate induced apoptosis in alveolar macrophages from rat lung. Toxicology

149: 109-114. Shakoor, A.; Gupta, P. K.; Singh, Y. P.; Kataria, M. (2000) Beneficial effe cts of aluminum on the progression of
lead-induced nephropathy in rats. Ph armacol. Toxicol. 87: 258-260.

Shalan, M. G.; Mostafa, M. S. ; Hassouna, M. M.; El-Nabi, S. E.; El-Refai e, A. (2005) Amelioration of lead toxicity
on rat liver with vitamin C and silymarin supplements. Toxicology 206: 1-15.

Shao, Z.; Suszkiw, J. B. (1991) Ca2+-surrogate action of Pb2+ on acetylcholine release from rat brain synaptosomes. J. Neurochem. 56: 568-574.
Sharifi, A. M.; Darabi, R.; Akbarloo, N.; Larijani, B.; Khoshbaten, A. (2004) Investigation of circulatory and tissue
ACE activity during development of lead-induced hypertension. Toxicol. Lett. 153: 233-238.
Shelkovnikov, S. A.; Gonick, H. C. (2001) Influence of lead on rat thoracic aorta contraction and relaxation. Am.
J. Hypertens. 14: 873-878. Shelton, K. R.; Egle, P. M. (1982) The proteins of lead-induced intranuclear inclusion bodies. J. Biol. Chem.

257: 11802-11807. Shelton, K. R.; Cunningham, J. G.; Klann, E.; Merchant, R. E.; Egle, P. M.; Bigbee, J. W. (1990) Low-abundance
32-kilodalton nuclear protein specifi cally enriched in the central ne rvous system. J. Neurosci. Res.

25: 287-294. Shelton, K. R.; Egle, P. M.; Bigbee, J. W.; Klann, E. (1 993) A nuclear matrix protein stabilized by lead exposure: current knowledge and future prospects. Presented at: Ninth international neurotoxicology conference;
October 1991; Little Rock, AR. Neurotoxicology 14(2-3): 61-67.

# AX5-227 Shenker, B. J.; Matarazzo, W. J.; Hirsch, R. L.; Gray, I. (1977) Trace metal modification of immunocompetence.
1. Effect of trace metals in the cultures on in vitro transformation of B lymphocytes. Cell. Immunol.

34: 19-24. Shinozuka, H.; Kubo, Y.; Katyal, S. L.; Coni, P.; Ledda-Co lumbano, G. M.; Columbano, A.; Nakamura, T. (1994)
Roles of growth factors and of tumor necrosis factor- α on liver cell proliferation induced in rats by lead

nitrate. Lab. Invest. 71: 35-41.
Shinozuka, H.; Ohmura, T.; Katyal, S. L.; Zedda, A. I.; Le dda-Columbano, G. M.; Columbano, A. (1996) Possible
roles of nonparenchymal ce lls in hepatocyte proliferation induced by lead nitrate and by tumor necrosis

factor α . Hepatology 23: 1572-1577.
Shraideh, Z. (1999) Effect of triethyl lead on perist altic contractile activity of the ileum of mice. Cytobios

99: 97-104. Shukla, V. K.; Prakash, A.; Tripathi, B. D.; Reddy, D. C.; Singh, S. (1998) Biliary heavy metal concentrations in
carcinoma of the gall bladder: case-control study. BMJ 317: 1288-1289.Sidhu, M. K.; Fernandez, C.; Khan, M. Y.; Kumar, S. (1991) Induction of morphological transformation, anchorageindependent growth and plasminogen activators in non-tumorigenic human osteosarcoma cells by lead

chromate. Anticancer Res. 11: 1045-1053. Sieg, D. J.; Billings, R. E. (1997) Lead/cytokine-mediate d oxidative DNA damage in cultured mouse hepatocytes.
Toxicol. Appl. Pharmacol. 142: 106-115.
Sierra, E. M.; Tiffany-Castiglioni, E. (1992) Effects of low-level lead exposure on hypothalamic hormones and serum progesterone levels in pregnant guinea pigs. Toxicology 72: 89-97.
Silbergeld, E. K. (1990) Toward the 21st century: lessons from lead and lessons yet to learn. Environ. Health
Perspect. 86: 191-196. Silbergeld, E. K.; Hruska, R. E.; Bradley, D. (1982) Neurotoxic aspects of porphyrinopathies: lead and
succinylacetone. Environ. Res. 29: 459-471.

Silkin, Y. A.; Silkina, E. N.; Sherst obitov, A. O.; Gusev, G. P. (2001) Activation of potassium channels in erythrocytes of marine teleost Scorpaena porcus. Membr. Cell Biol. 14: 773-782.
Simons, T. J. B. (1986a) Passive transport and binding of lead by human red blood cells. J. Physiol. 378: 267-286.
Simons, T. J. B. (1986b) The role of anion transport in the passive movement of lead across the human red cell membrane. J. Physiol. 378: 287-312.
Simons, T. J. B. (1988) Active transport of lead by the calcium pump in human red cell ghosts. J. Physiol. (London)

405: 105-13. Simons, T. J. B. (1993a) Lead transport and binding by human erythrocytes in vitro. Pflugers Arch. 423: 307-313.
Simons, T. J. B. (1993b) Lead-calcium interactions in cellular lead toxicity. Neurotoxicology 14(2-3): 77-86. Simons, T. J. B. (1995) The affinity of human erythrocyte porphobilinogen synthase for Zn2+ and Pb2+. Eur.

J. Biochem. 234: 178-183.
Singh, U. S.; Saxena, D.K.; Singh, C.; Murthy, R. C.; Ch andra, S. V. (1991) Lead-induced fetal nephrotoxicity in iron-deficient rats. Reprod. Toxicol. 5: 211-217.
Singh, A.; Cullen, C.; Dykeman, A.; Rice, D.; Foster, W. (1993a) Chronic lead exposu re induces ultrastructural
alterations in the monkey testis. J. Submicrosc. Cytol. Pathol. 25: 479-486. Singh, C.; Saxena, D. K.; Murthy, R. C.; Chandra, S. V. (1993b) Embryo-fetal development influenced by lead
exposure in iron-deficient rats. Hum. Exp. Toxicol. 12: 25-28.
Singh, J.; Pritchard, D. E.; Carlisle, D. L.; Mclean, J. A. ; Montaser, A.; Orenstein, J. M.; Patierno, S. R. (1999) Internalization of carcinogenic lead chromate particles by cultured normal human lung epithelial cells:

formation of intracellular lead-inclusion bodies and in duction of apoptosis. Toxicol. Appl. Pharmacol.

161: 240-248. Singh, V. K.; Mishra, K. P.; Rani, R.; Yadav, V. S.; Awasthi, S. K.; Garg, S. K. (2003) Immunomodulation by lead.

Immunol. Res. 28: 151-165.
Sivaprasad, R.; Nagaraj, M.; Varalakshmi, P. (2002) Lipoic acid in combination with a chelator ameliorates lead-induced peroxidative damages in rat kidney. Arch. Toxicol. 76: 437-441.
Sivaprasad, R.; Nagaraj, M.; Varalakshmi, P. (20 03) Combined efficacies of lipoic acid and meso-2,3-
dimercaptosuccinic acid on lead-induced erythrocyte membrane lipid peroxidation and antioxidant status in rats. Hum. Exp. Toxicol. 22: 183-192.
Sivaprasad, R.; Nagaraj, M.; Varalakshmi, P. (2004) Co mbined efficacies of lipoic aci d and 2,3-dimercaptosuccinic acid against lead-induced lipid peroxidation in rat liver. J. Nutr. Biochem. 15: 18-23
Skoczy ń ska, A.; Smolik, R. (1994) The effect of combined exposure to lead and cadmium on serum lipids and lipid
peroxides level in rats. Int. J. Occup. Med. Environ. Health 7: 263-271.

# AX5-228 Skoczy ń ska, A.; Smolik, R.; Jele ń , M. (1993) Lipid abnormalities in rats given small doses of lead. Arch. Toxicol.

67: 200-204. Skoczy ń ska, A.; Smolik, R.; Milian, A. (1994) The effect of combined exposure to lead and cadmium on the
concentration of zinc and copper in rat tissues. In t. J. Occup. Med. Environ. Health 7: 41-49.
Slobozhanina, E. I.; Kozlova, N. M.; Lukyanenko, L. M.; Oleksiuk, O. B.; Gabbianelli, R.; Fedeli, D.; Caulini, G. C.; Falcioni, G. (2005) Lead-induced changes in human erythrocytes and lymphocytes. J. Appl.

Toxicol. 25: 109-114.
Smejkalova, J. (1990) The chromosomal aberrations investig ation in children permanently living in the lead polluted area. Sb. Ved. Pr. Lek. Fak. Karlovy Univerzity Hradci Kralove 33: 539-564.
Smith, D. R.; Flegal, A. R. (1992) Stab le isotopic tracers of lead mobilized by DMSA chelation in low lead-exposed
rats. Toxicol. Appl. Pharmacol. 116: 85-91.
Smith, K. L.; Lawrence, D. A. (1988) Immunomodulation of in vitro antigen presentation by cations. Toxicol. Appl.

Pharmacol. 96: 476-484. Smith, C. M.; DeLuca, H. F.; Tanaka, Y.; Mahaffey, K. R. (1981) Effect of lead ingestion on functions of vitamin D

and its metabolites. J. Nutr. 111: 1321-1329.
Smith, C. M.; Hu, H.; Wang, X.; Kelsey, K. T. (1995a) ALA- D genotype is not associated with HT or HB levels among workers exposed to low levels of lead. Med. Lav. 86: 229-235.
Smith, C. M.; Wang, X.; Hu, H.; Kelsey, K. T. (1995b) A polymorphism in the δ -aminolevulinic acid dehydratase
gene may modify the pharmacokinetics and toxicity of lead. Environ. Health Perspect. 103: 248-253. Smith, D.; Bayer, L.; Strupp, B. J. (1998 a) Efficacy of succimer ch elation for reducing brain Pb levels in a rodent

model. Environ. Res. 78: 168-176.
Smith, D. R.; Kahng, M. W.; Quintanilla-Vega, B.; Fowler, B. A. (1998b) High-affinity renal lead-binding proteins ini environmentally-exposed humans. Chem. Biol. Interact. 115: 39-52.
Smith, D. R.; Woolard, D.; Luck, M. L.; Laughlin, N. K. (2000) Succimer and the reduction of tissue lead in
juvenile monkeys. Toxicol. Appl. Pharmacol. 166: 230-240. Snyder, R. D.; Lachmann, P. J. (1989) Thiol involvement in the inhibition of DNA repair by metals in mammalian

cells. J. Mol. Toxicol. 2: 117-128.
Snyder, J. E.; Filipov, N. M.; Parsons, P. J.; Lawrence, D. A. (2000) The efficiency of matern al transfer of lead and its influence on plasma IgE and splenic cellularity of mice. Toxicol. Sci. 57: 87-94.
Sokol, R. Z. (1987) Hormonal effects of lead acetate in the male rat: mechanism of action. Biol. Reprod.

37: 1135-1138. Sokol, R. Z. (1989) Reversibility of the toxic effect of lead on the male reproductive axis. Reprod. Toxicol.

3: 175-180. Sokol, R. Z. (1990) The effect of duration of exposure on the expression of lead toxicity on the male reproductive

axis. J. Androl. 11: 521-526.
Sokol, R. Z.; Berman, N. (1991) The effect of age of exposure on lead-induced testicular toxicity. Toxicology

69: 269-278. Sokol, R. Z.; Madding, C. E.; Swerdloff, R. S. (1985) Le ad toxicity and the hypothalamic-pituitary-testicular axis.
Biol. Reprod. 33: 722-728. Sokol, R. Z.; Okuda, H.; Nagler, H. M. ; Berman, N. (1994) Lead exposure in vivo alters the fertility potential of

sperm in vitro . Toxicol. Appl. Pharmacol. 124: 310-316.
Sokol, R. Z.; Berman, N.; Okuda, H.; Raum, W. (1998) Effects of lead exposure on GnRH and LH secretion in male rats: response to castration and α -methyl- p -tyrosine (AMPT) challenge. Reprod. Toxicol. 12: 347-355.
Sokol, R. Z.; Wang, S.; Wan, Y.-J. Y.; Stanczyk, F. Z.; Gentzschein, E.; Chap in, R. E. (2002) Long-term, low-dose
lead exposure alters the gonadotropin-releasing hormone system int he male rat. Environ. Health Perspect.

110: 871-874. Somashekaraiah, B. V.; Padmaja, K.; Prasad, A. R. K. (1992) Lead-induced lipid peroxidation and antioxidant
defense components of developing chick embryos. Free Radic. Biol. Med. 13: 107-114. Spit, B. J.; Wibowo, A. A. E.; Feron, V. J.; Zielhuis, R. L. (1981) Ultrastruc tural changes in the kidneys of rabbits

treated with lead acetate. Arch. Toxicol. 49: 85-91.
Srivastava, D.; Hurwitz, R. L.; Fox, D. A. (1995) Le ad- and calcium-mediated inhibition of bovine rod cGMP phosphodiesterase: interactions with magne sium. Toxicol. Appl. Pharmacol. 134: 43-52. Srivastava, V.; Dearth, R. K.; Hiney, J. K.; Ramirez, L. M. ; Bratton, G. R.; Dees, W. (2004) The effects of low-level Pb on steroidogenic acute regulatory protein (StAR) in the prepubertal rat ovary. Toxicol. Sci. 77: 35-40.

# AX5-229 Stangle, D. E.; Strawderman, M. S.; Smith, D.; Kuypers, M.; Strupp, B. J. (2004) Reductions in blood lead
overestimate reductions in brain lead following repeated succimer regimens in a rodent model of childhood lead exposure. Environ. Health Perspect. 112: 302-308.
Steenland, K.; Selevan, S.; Landrigan, P. (1992) The morta lity of lead smelter workers: an update. Am. J. Public

Health 82: 1641-1644. Stokes, J.; Casale, T. B. (2004) Rationale for new treatments aimed at IgE immunomodulation. Ann. Allergy

Asthma Immunol. 93: 212-217.
Stowe, H. D.; Goyer, R. A. (1971) The reproductive ability and progeny of F 1 

# lead-toxic rats. Fertil. Steril.

22: 755-760.

Stru ż y ń ska, L.; Walski, M.; Gadamski, R.; Dabrowska-Bouta, B.; Rafa ł owska, U. (1997) Lead-induced
abnormalities in blood-brain barrier permeability in experimental chronic toxicity. Mol. Chem. Neuropathol.

31: 207-224. Studnitz, W. von; Haeger-Aronsen, B. (1962) Urinary excretion of amino acids in lead-poisoned rabbits. Acta

Pharmacol. Toxicol. 19: 36-42.
Sugawara, E.; Nakamura, K.; Fukumura, A.; Seki, Y. ( 1990) Uptake of lead by human red blood cells and

intracellular distribution. Kitasato Arch. Exp. Med. 63: 15-23. Sugiura, S.; Dhar, S. K.; Arizono, K.; Ariyoshi, T. (1993) Induction of DT-diaphorase in the liver of rats treated
with various metals. Jpn. J. Toxicol. Environ. Health 39: 7.
Suketa, Y.; Hasegawa, S.; Yamamoto, T. (1979) Changes in sodium and potassium in urine and serum of leadintoxicated rats. Toxicol. Appl. Pharmacol. 47: 203-207.

Sun, L. R.; Suszkiw, J. B. (1995) Extracellular inhi bition and intracellular enhancement of Ca2+ currents by Pb2+ in
bovine adrenal chromaffin cells. J. Neurophysiol. 74: 574-581.

Sun, L.; Hu, J.; Zhao, Z.; Li, L.; Ch eng, H. (2003) Influence of exposure to environmental lead on serum
immunoglobulin in preschool children. Environ. Res. 92: 124-128.
Suszkiw, J. B. (2004) Presynaptic disruption of transmitter release by lead. Neurotoxicology 25: 599-604.

Suszkiw, J.; Toth, G.; Muraws ky, M.; Cooper, G. P. (1984) Effects of Pb2+ and Cd2+ on acetylcholine release and
Ca2+ movements in synaptosomes and subcellular fractions from rat brain and Torpedo electric organ.

Brain Res. 323: 31-46. Suwalsky, M.; Villena, F.; Norris, B.; Cuevas, F.; Sotomayor, C. P.; Zatta, P. (2003) Effects of lead on the human
erythrocyte membrane and molecular models. J. Inorg. Biochem. 97: 308-313.

Suzuki, T.; Morimura, S.; Diccianni, M. B.; Yamada, R.; Hochi, S.-I.; Hirabayashi, M.; Yuki, A.; Nomura. K.; Kitagawa, T.; Imagawa, M.; Muramatsu, M. (1996) Activation of glutathione transferase P gene by lead
requires glutathione transferase P enhancer I. J. Biol. Chem. 271: 1626-1632. Szabo, A.; Merke, J.; Hügel, U.; Ma ll, G.; Stoeppler, M.; Ritz, E. (19 91) Hyperparathyroidism and abnormal
1,25(OH) 2 

# vitamin D 3 

# metabolism in experimental lead intoxication. Eur. J. Clin. Invest. 21: 512-520.
Tabchoury, C. M.; Pearson, S. K.; Bowen, W. H. (1999) Influence of lead on the car iostatic effect of fluoride co-crystallized with sucrose in desalivated rats. Oral Dis. 5: 100-103.
Takeno, M.; Yoshikawa, H.; Kurokawa, M.; Takeba, Y.; Kashoiwakura, J. I.; Sakaguchi, M.; Yasueda, H.; Suzuki,
N. (2004) Th1-dominant shift of T cell cytokine production and subsequent reduction of serum immunoglobulin E response by administration in vivo of plasmid expressing Txk/Rlk, a member of Tec
family tyrosine kinases, in a mouse model. Clin. Exp. Immunol. 34: 965-970.
Taketani, S.; Tanaka, A.; Tokunaga, R. (1985) Reconstitu tion of heme-synthesizing activity from ferric ion and porphyrins, and the effect of lead on the activity. Arch. Biochem. Biophys. 242: 291-296.
Tandon, S. K.; Dhawan, M.; Kumar, A.; Flora, S. J. S. (1992) Influence of selenium supplementation during

chelation of lead in rats. Indian J. Physiol. Pharmacol. 36: 201-204.
Tandon, S. K.; Khandelwal, S.; Jain, V. K.; Mathur, N. (199 3) Influence of dietary iron deficiency on acute metal

intoxication. Biometals 6: 133-138.
Tandon, S. K.; Khandelwal, S.; Jain, V. K.; Mathur, N. (199 4) Influence of dietary iron deficiency on nickel, lead

and cadmium intoxication. Sci. Total Environ. 148: 167-173.
Tandon, S. K.; Singh, S.; Prasad, S.; Mathur, N. (1997) Influence of L-lysine and zinc administration during
exposure to lead or lead and ethanol in rats. Biol. Trace Elem. Res. 57: 51-58. Tandon, S. K.; Singh, S.; Prasad, S.; Srivastava, S.; Siddiqui, M. K. (2002) Reversal of lead-induced oxidative stress
by chelating agent, antioxidant, or their combin ation in the rat. Environ. Res. 90: 61-66. Taupeau, C.; Poupon, J.; Nomé, F.; Lefévre, B. (2001) Lead accumulation in the mouse ovary after treatmentinduced follicular atresia. Reprod. Toxicol. 15: 385-391.

# AX5-230 Tavakoli-Nezhad, M.; Pitts, D. K. (2005) Postnatal inorga nic lead exposure reduces midbrain dopaminergic impulse
flow and decreases dopamine D1 receptor sensitivity in nucleus accumbens neurons. J. Pharmacol. Exp.

Ther. 312: 1280-1288.
Tavakoli-Nezhad, M.; Barron, A. J.; Pitts, D. K. (2001) Po stnatal inorganic lead exposure decreases the number of
spontaneously active midbrain dopamine neurons in the rat. Neurotoxicology 22: 259-269. Taylor, S. A.; Chivers, I. D.; Price, R. G.; Arce-Thomas, M.; Milligan, P.; Francini, I. ; Alinovi, R.; Cavazzini, S.;
Bergamaschi, E.; Vittori, M.; Mutti, A. ; Lauwerys, R. R.; Bern ard, A. M.; Roels, H. A.; De Broe, M. E.; Nuyts, G. D.; Elseviers, M. M.; Hotter, G.; Ramis, I.; Rosello, J.; Gelpi, E.; Stolte, H.; Eisenberger, U.; Fels, L. M. (1997) The assessment of biomarkers to detect nephrotoxicity using an integrated database.

Environ. Res. 75: 23-33.
Tchernitchin, N. N.; Villagra, A.; Tche rnitchin, A. N. (1998a) Antiestrogenic activity of lead. Environ. Toxicol.
Water Qual. 13: 43-53.

Tchernitchin, N. N.; Tchernitchin, A. N.; Mena, M. A.; Villarroel, L.; Guzmán, C.; Polo ni, P. (1998b) Effect of subacute exposure to lead on responses to estrogen in the immature rat uterus. Bull. Environ. Contam.

Toxicol. 60: 759-765.
Tepper, R. I.; Levinson, D. A.; Stanger, B. Z.; Campos-Torres, J.; Abbas, A. K.; Leder, P. (1990) IL-4 induces allergic-like inflammatory disease and alters T cell development in transgenic mice. Cell 62: 457-467.
Teraki, Y.; Uchiumi, A. (1990) Inorgani c elements in the tooth an d bone tissues of rats b earing nickel acetate- and

lead acetate-induced tumors . Shigaku. 78: 269-273. Terayama, K. (1993) Effects of lead on electrophoretic mob ility, membrane sialic acid, deformability and survival of
rat erythrocytes. Ind. Health 31: 113-126.
Terayama, K.; Muratsugu, M. (1988) Effects of lead on sialic acid content and survival of rat erythrocytes. Toxicology 53: 269-276.
Terayama, K.; Maehara, N.; Muratsugu, M.; Makino, M.; Ya mamura, K. (1986) Effect of lead on electrophoretic
mobility of rat erythrocytes. Toxicology 40: 259-265.

Tessitore, L.; Perletti, G. P.; Sesca, E.; Pani, P.; Dianzani, M. U.; Piccinini , F. (1994) Protein kinase C isozyme
pattern in liver hyperplasia. Biochem. Biophys. Res. Commun. 205: 208-214.
Tessitore, L.; Sesca, E.; Pani, P.; Dianzani, M. U. (199 5) Sexual dimorphism in the regulation of cell turnover during liver hyperplasia. Chem. Biol. Interact. 97: 1-10.

Thaweboon, S.; Chunhabundit, P.; Surarit, R.; Swasdison, S.; Suppukpatana, P. (2002) Effects of lead on the
proliferation, protein production, and osteocalcin secretion of human dental pulp cells in vitro . Southeast Asian J. Trop. Med. Public Health 33: 654-661.
Thind, I. S.; Khan, M. Y. (1978) Potentiation of the neurovirulence of Langat virus infection by lead intoxication in mice. Exp. Mol. Pathol. 29: 342-347.
Thoreux-Manlay, A.; Le Goascogne, C.; Segretain, D.; Jégou, B.; Pinon-Lataillade, G. (1995a) Lead affects
steroidogenesis in rat Leydig cells in vivo and in vitro. Toxicology 103: 53-62. Thoreux-Manlay, A.; Vélez de la Calle, J. F.; Olivier, M. F.; Soufir, J. C.; Masse, R. ; Pinon-Lataillade, G. (1995b)
Impairment of testicular endocrine function after lead intoxication in the adult rat. Toxicology 100: 101-109.
Tian, L.; Lawrence, D. A. (1995) Le ad inhibits nitric oxide production in vitro by murine splenic macrophages. Toxicol. Appl. Pharmacol. 132: 156-163.
Tian, L.; Lawrence, D. A. (1996) Metal-induced modulation of nitric oxide production in vitro by murine
macrophages: Lead, nickel, and cobalt utilize diff erent mechanisms. Toxicol. Appl. Pharmacol.

141: 540-547. Tian, X.; Sun, X.; Suszkiw, J. B. (2000) Upregulation of tyrosine hydroxylase and downregulation of choline
acetyltransferase in lead-exposed PC 12 cells: the role of PKC activation. Toxico l. Appl. Pharmacol.

167: 246-252. Tomczok, J.; Grzybek, H.; Ś liwa, W.; Panz, B. (19 88) Ultrastructural aspects of the small intestinal lead toxicology.
Part II. The small intestine goblet cells of rats during lead poisoning. Exp. Pathol. 35: 93-100.

Tomczok, J.; Ś liwa-Tomczok, W.; Grzybek, H. (1991) The small intestinal en terocytes of rats during lead
poisoning: the application of the Timm sulphide silver method and an ultrastructural study. Exp. Pathol.

42: 107-113. Tomokuni, K.; Ichiba, M. (1988) Comparison of inhibitio n of erythrocyte pyrimidine 5'-nucleotidase and deltaaminolevulinic acid dehydratase by lead. Toxicol. Lett. 40: 159-163.
Tomokuni, K.; Ichiba, M. (1990) Effect of lead on th e activity of erythrocyte porphobilinogen deaminase in-vivo

and in-vitro. Toxicol. Lett. 50: 137-142.

# AX5-231 Tomokuni, K.; Ichiba, M.; Hirai, Y. (1989) Effect of lead exposure on some biological indices related to porphyrin
metabolism and the activity of erythrocyte pyrimidine 5' -nucleotidase in the mice. Arch. Toxicol. 63: 23-28.
Tomokuni, K.; Ichiba, M.; Hirai, Y. ( 1991) Elevated urin ary excretion of β -aminoisobutyric acid and

δ -aminolevulinic acid (ALA) and the inhibition of AL A-synthase and ALA-dehydratase activities in both
liver and kidney in mice exposed to lead. Toxicol. Lett. 59: 169-173. Tomsig, J. L.; Suszkiw, J. B. (199 3) Intracellular mechanism of Pb2+-ind uced norepinephrine release from bovine
chromaffin cells. Am. J. Physiol. 265: C1630-C1636.
Tomsig, J. L.; Suszkiw, J. B. (1995) Multisite interactions between Pb2+ and protein kinase C and its role in norepinephrine release from bovine adrenal chromaffin cells. J. Neurochem. 64: 2667-2673.
Tomsig, J. L.; Suszkiw, J. B. (1996) Metal selectivity of exocytosis in alpha-toxin-permeabilized bovine chromaffin

cells. J. Neurochem. 66: 644-650. Tonner, L. E.; Heiman, A. S. (1997) Lead may affect glucocorticoid signal transduction in cultured hepatoma cells
through inhibition of protein kinase C. Toxicology 119: 155-166. Toplan, S.; Ozcelik, D.; Gulyasar, T.; Akyoleu, M. C. (2 004) Changes in hemorheological parameters due to lead
exposure in female rats. J. Tr ace Elem. Med. Biol. 18: 179-182.
Torres, D.; Barrier, M.; Bihl, F.; Ques niaux, V. J.; Maillet, I.; Akira, S.; Ryffel, B.; Erard, F. (2004) Toll-like receptor 2 is required for optimal control of Li steria monocytogenes infection. Infect. Immun.

72: 2131-2139. Toscano, C. D.; Hashemzadeh-Gargari, H.; McGlothan, J. L. ; Guilarte, T. R. (2002) Developmental Pb2+ exposure alters NMDAR subtypes and reduces CREB phosphorylation in the rat brain. Dev. Brain Res. 139: 217-226.
Trasande, L.; Thurston, G. D. (2005) The role of air pollu tion in asthma and other pediatric morbidities. J. Allergy

Clin. Immunol. 115: 689-699. Trejo, R. A.; Di Luzio, N. R.; Loose, L. D.; Hoffman, E. (1972) Reticuloendothelial and hepatic functional
alterations following lead acetate administration. Exp. Mol. Pathol. 17: 145-158.
Trombini, T. V.; Pedroso, C. G.; Ponce, D.; Almeida, A. A.; Godinho, A. F. (2001) Developmental lead exposure in rats: is a behavioral sequel extended at F2 generation? Pharmacol. Biochem. Behav. 68: 743-751.
Tryphonas, H. (2001) Approaches to detecting immunotoxic effects of environmental contaminants in humans.
Environ. Health Perspect. Suppl. 109(6): 877-884. Tsao, D.-A.; Yu, H.-S.; Cheng, J.-T.; Ho, C.-K.; Chang, H.-R. (2000) The change of β -adrenergic system in
lead-induced hypertension. Toxicol. Appl. Pharmacol. 164: 127-133.
Tulasi, S. J.; Reddy, P. U. M.; Ramana Rao, J. V. (1992) Accumulation of lead and effects on total lipids and lipid

derivatives in the freshwater fish Anabas testudineus (Bloch). Ecotoxicol. Environ. Saf. 23: 33-38.
U.S. Environmental Protection Agency. (1986a) Air quality criteria for lead. Research Tr iangle Park, NC: Office of

Health and Environmental Assessment, Environmental Criteria and Assessment Office; EPA report no.
EPA-600/8-83/028aF-dF. 4v. Available from: NTIS, Springfield, VA; PB87-142378.
U.S. Environmental Protection Agency. (1986b) Lead effe cts on cardiovascular functi on, early development, and stature: an addendum to U.S. EPA Air Quality Criteria for Lead (1986). In: Air quality criteria for lead, v. 1.
Research Triangle Park, NC: Office of Health and Environmental Assessment, Environmental Criteria and
Assessment Office; pp. A1-A67; EPA report no. EPA-600/8-83/028aF. Available from: NTIS, Springfield,

VA; PB87-142378. U.S. Environmental Protection Agency. (1990) Air quality criteria for lead: supplement to the 1986 addendum.
Research Triangle Park, NC: Office of Health and Environmental Assessment, Environmental Criteria and Assessment Office; report no. EPA/600/8-89/049F. Available from: NTIS, Springfield, VA; PB91-138420.
Ueda, D.; Kishimoto, T.; Dekio, S.; Tada, M. (1997) Inhibitory effect of lead on tube formation by cultured human

vascular endothelial cells. Hum. Cell 10: 283-291. Ünde ğ er, Ü.; Ba ş aran, N.; Canpinar, H.; Kansu, E. (1996) Immune alterations in lead-exposed workers. Toxicology

109: 167-172. Upasani, C. D.; Khera, A.; Balaraman, R. (20 01) Effect of lead with vitamin E, C, or Spirulina on malondialdehyde, conjugated dienes and hydroperoxides in rats. Indian J. Exp. Biol. 39: 70-74.
Vaglenov, A.; Carbonell, E.; Marcos, R. (1998) Biomonitoring of workers exposed to lead. Genotoxic effects, its
modulation by polyvitamin treatment and evaluation of the induced radioresistance. Mutat. Res. 418: 79-92.

Vakharia, D. D.; Liu, N.; Pause, R.; Fa sco, M.; Bessette, E.; Zhang, Q.-Y.; Kaminsky, L. S. (2001) Effect of metals
on polycyclic aromatic hydrocarbon induction of CYP1A1 and CYP1A2 in human hepatocyte cultures. Toxicol. Appl. Pharmacol. 170: 93-103.

Valencia, I.; Castillo, E. E.; Chamorro, G.; Bobadilla, R. A.; Castillo, C. (2001) Lead induces endothelium- and
Ca2+-independent contraction in rat aortic rings. Pharmacol. Toxicol. (Oxford, UK) 89: 177-182.

# AX5-232 Valentino, M.; Governa, M.; Marchiseppe, I.; Visona, I. (1991) Effects of lead on polymorphonuclear leukocyte
(PMN) functions in occupationally exposed workers. Arch. Toxicol. 65: 685-688. Valverde, M.; Fortoul, T. I.; Diaz-Barriga, F.; Majia, J. ; Del Castillo, E. R. (2002) Genotoxicity induced in CD-1
mice by inhaled lead: differential organ response. Mutagenesis 17: 55-61.

Van Gelder, G. A.; Carson, T.; Smith, R. M.; Buck, W. B. (1973) Behavioral toxi cologic assessment of the neurologic effect of lead in sheep. Clin. Toxicol. 6: 405-418.
Van Larebeke, N.; Koppen, G.; Nelen, V.; Schoeters, G. ; Van Loon H, Albering H, Riga L, Vlietinck, R.;
Kleinjans, J.; Flemish Environment and Health Study Group. (2004) Differences in HPRT mutant frequency among middle-aged Flemish women in association with area of residence and blood lead levels. Biomarkers

9: 71-84.
Vander, A. J. (1988) Chronic effects of lead on the renin-angiotensin system. In: Victery, W., ed. Symposium on lead-blood pressure relationships; April 1987; Chapel Hill, NC. Environ. Health Perspect. 78: 77-83.
Vander, A. J.; Taylor, D. L.; Kalitis, K.; Mouw, D. R.; Victer y, W. (1977) Renal handling of lead in dogs: clearance studies. Am. J. Physiol. 2: F532-F538.

Varnai, V. M.; Piasek, M.; Blanuša, M.; Šari ć , M. M.; Kostial, K. (2001) Succimer treatment during ongoing lead
exposure reduces tissue lead in suckling rats. J. Appl. Toxicol. 21: 415-416. Vaziri, N.; Ding, Y. (2001) Effect of lead on nitric oxide synthase expression in coronary endothelial cells: role of
superoxide. Hypertension 37: 223-226.
Vaziri, N. D.; Wang, X. Q. (1999) cGMP-mediated negative -feedback regulation of endothelial nitric oxide synthase expression by nitric oxide. Hypertension 34: 1237-1241.
Vaziri, N. D.; Ding, Y.; Ni, Z.; Gonick, H. C. (1997) Altered nitric oxide metabolis m and increased oxygen free
radical activity in lead-induced hypertension: effect of lazaroid therapy. Kidne y Int. 52: 1042-1046. Vaziri, N. D.; Ding, Y.; Ni, Z. (1999a) Nitric oxide synthase expression in the course of lead-induced hypertension.
Hypertension 34: 558-562.
Vaziri, N. D.; Liang, K.; Ding, Y. (1 999b) Increased nitric oxide inactivation by reactive oxygen species in leadinduced hypertension. Kidney Int. 56: 1492-1498.
Vaziri, N. D.; Wang, X. Q.; Oveisi, F.; Rad, B. (2000) I nduction of oxidative stress by glutathione depletion causes
severe hypertension in normal rats. Hypertension 36: 142-146. Vaziri, N. D.; Ding, Y.; Ni, Z. (2001) Compensatory up-regulation of nitric-oxide synthase isoforms in lead-induced
hypertension; reversal by a superoxide dismutase-mimetic drug. J. Pharmacol. Exp. Ther. 298: 679-685.
Vaziri, N. D.; Lin, C.-Y.; Farmand, F.; Sindhu, R. K. (2003) Superoxide dismutase, catalase, glutathione peroxidase and NADPH oxidase in lead-induced hypertension. Kidney Int. 63: 186-194.
Vaziri, N. D.; Ding, Y.; Ni, Z.; Barton, C. H. (2005) Br adykinin down-regulates, wh ereas arginine analogs upregulates, endothelial nitric-oxide synthase expression in coronary endothelial cells. J. Pharmacol. Exp.

Ther. 313: 121-126.
Vermande-van Eck, G. J.; Meigs, J. W. (1960) Changes in the ovary of the rhesus monkey after chronic lead

intoxication. Fertil. Steril. 11: 223-234.

Vicente, A.; Varas, A.; Acedon, R. S.; Jimenez, E.; Muno z, J. J.; Zapata, A. G. (1998) Appearance and maturation
of T-cell subsets during rat thymus development. Dev. Comp. Immunol. 5: 319-331. Victery, W.; Vander, A. J.; Mouw, D. R. (1979a) Effect of acid-base status on renal excretion and accumulation of
lead in dogs and rats. Am. J. Physiol. 237: F398-F407.
Victery, W.; Vander, A. J.; Mouw, D. R. (1979b) Renal hand ling of lead in dogs: stop-flow analysis. Am. J. Physiol.

237: F408-F414. Victery, W.; Soifer, N. E.; Weiss, J. S.; Vander, A. J. (1981) Acute effects of lead on the renal handling of zinc in
dogs. Toxicol. Appl. Pharmacol. 61: 358-367. Victery, W.; Vander, A. J.; Markel, H.; Katzman, L.; Sh ulak, J. M.; Germain, C. (1982a) Lead exposure, begun

in utero , decreases renin and angiotensin II in adult rats. Proc. Soc. Exp. Biol. Med. 170: 63-67.
Victery, W.; Vander, A. J.; Shulak, J. M.; Schoeps, P.; Julius, S. (1982b) Lead, hypertension, and the reninangiotensin system in rats. J. Lab. Clin. Med. 99: 354-362.
Victery, W.; Vander, A. J.; Schoeps, P.; Germain, C. (1983) Plasma renin is increased in young rats exposed to lead

in utero and during nursing. Proc. Soc. Exp. Biol. Med. 172: 1-7. Vij, A. G.; Satija, N. K.; Flora, S. J. (1998) Lead indu ced disorders in hematopoietic and drug metabolizing enzyme
system and their protection by ascorbic acid supplementation. Biomed. Environ. Sci. 11: 7-14. Villagra, R.; Tchernitchin, N. N.; Tchernitchin, A. N. (1997) Effect of subacute exposure to lead and estrogen on
immature pre-weaning rat leukocytes. Bull. Environ. Contam. Toxicol. 58: 190-197.

# AX5-233 Virgolini, M. B.; Chen, K.; Weston, D. D.; Bauter, M. R.; Cory-Slechta, D. A. (2005) Interactions of chronic lead
exposure and intermittent stress: consequences for brain catecholamine systems and associated behaviors

and HPA axis function. Toxicol. Sci. 87: 469-482.
Virgolini, M. B.; Bauter, M. R.; Weston, D. D.; Cory-S lechta, D. A. (2006) Permanent alterations in stress
responsivity in female offspring subjected to combined maternal lead exposure and/or stress. Neurotoxicology 27: 11-21.
Vyskocil, A.; Cizkova, M. (1996) Nephrotoxic effects of unleaded petrol in female rats. J. Appl. Toxicol. 16: 55-56.
Vyskocil, A.; Pancl, J.; Tusi, M.; Ettlerova, E.; Semeck y, V.; Kašparová, L.; Lauwer ys, R.; Bernard, A. (1989) Dose-related proximal tubular dysfunction in male rats chronically exposed to lead. J. Appl. Toxicol.

9: 395-399. Vysko č il, A.; Fiala, Z.; Šalandova, J.; Popler, A.; Ettlerová, E.; Emminger, S. (1991) The urin ary excretion of specific proteins in workers exposed to lead. Arch. Toxicol. Suppl. 14: 218-221.
Vyskocil, A.; Cizkova, M.; Tejnorova, I. (1995) Effect of prenatal and postnatal exposure to lead on kidney function in male and female rats. J. Appl. Toxicol. 15: 327-328.
Waalkes, M. P.; Liu, J.; Goyer, R. A.; Diwan, B. A. (2004) Metallothionein-I/II double knockout mice are
hypersensitive to lead-induced kidney carcinogenesis: role of inclusion body formation. Cancer Res.

64: 7766-7772.
Wadi, S. A.; Ahmad, G. (1999) Effects of lead on the male reproductive system in mice. J. Toxicol. Environ. Health

Part A 56: 513-521.
Wagerová, M.; Wagne r, V.; Mádlo, Z.; Zav ázal, V.; Wokounvá, D.; Kř íž, J.; Mohyla, O. (1986) Seasonal variations
in the level of immunoglobulins and serum proteins of children differing by exposure to air-borne lead.
J. Hyg. Epidem. Microbiol. 30: 127-138. Wapnir, R. A.; Moak, S. A.; Lifshitz, F.; Teichberg, S. (197 9) Alterations of intestinal and renal functions in rats
after intraperitoneal injections of lead acetate. J. Lab. Clin . Med. 94: 144-151.
Warner, G. L.; Lawrence, D. A. (1986) Stimulation of murine lymphocyte responses by cations. Cell. Immunol.

101: 425-439. Waterman, S. J.; El-Fawal, H. A. N.; Snyder, C. A. (1994) Lead alters the immunogenicity of two neural proteins:
A potential mechanism for the progression of lead-i nduced neurotoxicity. Environ. Health Perspect.

102: 1052-1056.
Watson, G. E.; Davis, B. A.; Raubertas, R. F.; Pearson, S. K.; Bowen, W. H. (1997) Influence of maternal lead
ingestion on caries in rat pups. Nature Med. 3: 1024-1025.
Watts, S. W.; Chai, S.; Webb, R. C. (1 995) Lead acetate-induced contraction in rabbit mesenteric artery: interaction
with calcium and protein kinase C. Toxicology 99: 55-65. Webb, R. C.; Winquist, R. J.; Victery, W.; Vander, A. J. (1981) In vivo and in vitro effects of lead on vascular
reactivity in rats. Am. J. Physiol. 241: H211-H216.
Wedeen, R. P. (1992) Removing lead from bone: clinical implications of bone lead stores. Neurotoxicology

13: 843-852. Wedrychowski, A.; Schmidt, W. N.; Hnilica, L. S. (1986) The in vivo cross-linking of proteins and DNA by heavy

metals. J. Biol. Chem. 261: 3370-3376.
Weiler, E.; Khalil-Manesh, F.; Gonick, H. C. (1990) Effects of lead and a low-molecular-weight endogenous plasma
inhibitor on the kinetics of sodium - potassium-activated adenosine triphosphatase and potassium-activated
para-nitrophenylphosphatase. Clin. Sci. 79: 185-192. Weisskopf, M. G.; Hu, H.; Mulkern, R. V.; White, R.; Aro, A.; Oliveira, S.; Wri ght, R. O. (2004a) Cognitive deficits
and magnetic resonance spectroscopy in adult monozygotic twins with lead poisoning. Environ. Health
Perspect. 112: 620-625. Weisskopf, M. G.; Wright, R. O.; Schwar tz, J.; Spiro, A., III; Sparrow, D.; Ar o, A.; Hu, H. (2004b) Cumulative lead
exposure and prospective change in cognition among elderly men. The VA Normative Aging Study. Am.
J. Epidemiol. 160: 1184-1193. Weller, C. V. (1915) The blastophthoric effect of chronic lead poisoning. J. Med. Res. 33: 271-293.

Wenda-Ró ż ewicka, L.; Marchlewicz, M.; Barcew -Wiszniewska, B.; Piasecka, M. (1 996) The ultrastructure of the
testis in rats after long-term treatment with lead acetate. An drologia 28: 97-102. Westerink, R. H.; Vijverberg, H. P. (2002) Ca2+-independent vesicular catecholamine release in PC12 cells by

nanomolar concentrations of Pb2+. J. Neurochem. 80: 861-867. Wetmur, J. G. (1994) Influence of the common human delta-aminolevulinate dehydratase polymorphism on lead
body burden. Environ. Health Perspect. 102(suppl. 3): 215-219.

# AX5-234 Wetmur, J. G.; Lehnert, G.; Desnick, R. J. (1991) The δ -aminolevulinate dehydratase polymorphism: higher blood
lead levels in lead workers and environmentally exposed children with the 1-2 and 2-2 isozymes. Environ.

Res. 56: 109-119. Wicklund, K. G.; Daling, J. R.; Allard, J.; Weiss, N. S. (1988) Respiratory cancer among orchardists in Washington
State, 1968-1980. J. Occup. Med. 30: 561-564. Wide, M. (1985) Lead exposure on critical days of feta l life affects fertility in the female mouse. Teratology

32: 375-380. Wide, M.; D'Argy, R. (1986) Effect of inorganic lead on the primordial germ cells in the mouse embryo. Teratology

34: 207-212. Wide, M.; Nilsson, O. (1977) Differential susceptibility of th e embryo to inorganic lead during periimplantation in
the mouse. Teratology 16: 273-276.
Wide, M.; Nilsson, B. O. (1979) In terference of lead with implantation in the mouse: a study of the surface
ultrastructure of blastocysts and e ndometrium. Teratology 20: 101-113. Widzowski, D. V.; Cory-Slechta, D. A. (1994) Homogeneity of regional brain lead concentrations. Neurotoxicology

15: 295-308.
Wiebe, J. P.; Barr, K. J. (1988) Effect of prenatal and neonatal exposure to lead on the affinity and number of estradiol receptors in the uterus. J. Toxicol. Environ. Health 24: 451-460.
Wiebe, J. P.; Barr, K. J.; Buckingham, K. D. (1988) E ffect of prenatal and neonatal exposure to lead on
gonadotropin receptors and steroidogenesis in rat ovaries. J. To xicol. Environ. H ealth 24: 461-476.

Wiemann, M.; Schirrmacher, K.; Büsselb erg, D. (1999) Interference of lead with the calcium release activated

calcium flux of osteoblast-like cells. Calcif. Tissue Int. 65: 479-485.
Wise, J. P.; Leonard, J. C.; Patierno, S. R. (1992) Clasto genicity of lead chromate particles in hamster and human

cells. Mutat. Res. 278: 69-79.
Wise, J. P.; Orenstein, J. M.; Patierno, S. R. (1993) Inhibition of lead chromate clastogenesis by ascorbate:
relationship to particle dissolution and uptake. Carcinogenesis (London) 14: 429-434.

Wise, J. P., Sr.; Stearns, D. M.; Wetterhahn, K. E.; Patiern o, S. R. (1994) Cell-enhanced dissolution of carcinogenic
lead chromate particles: the role of individual di ssolution products in clast ogenesis. Carcinogenesis

15: 249-2254. Wise, J. P. Sr.; Wise, S. S.; Little, J. E. (2002) The cy totoxicity and genotoxicity of particulate and soluble
hexavalent chromium in human lung cells. Mutat. Res. 517: 221-229.

Wise, S. S.; Schuler, J. H.; Holmes, A. L. ; Katsifis, S. P.; Ketterer, M. E.; Hartso ck, W. J.; Zheng, T.; Wise, J. P., Sr. (2004a) Comparison of two particulate hexavalent chromium compounds: Barium chromate is more
genotoxic than lead chromate in human lung cells. Environ. Mol. Mutagen. 44: 156-162.

Wise S. S.; Holmes A. L.; Ketterer, M. E.; Hartsock, W. J.; Fomchenko, E.; Katsifis, S.; Thompson, W. D.;
Wise, J. P. Sr. (2004b) Chromium is the proximate clastogenic species for lead chromate-induced
clastogenicity in human bronchial cells. Mutat. Res. 560: 79-89.

Wise, S. S.; Holmes, A. L.; Moreland, J. A.; Xie, H .; Sandwick, S. J.; Stackpole, M. M.; Fomchenko, E.;
Teufack, S.; May, A. J., Jr.; Katsfis, S. P.; Wise, J. P., Sr. (2005) Human lung cell growth is not stimulated
by lead ions after lead chromate-induced genotoxicity. Mol. Cell. Biochem. 279: 75-84. Wisotzky, J.; Hein, J. W. (1958) Effects of drinking solutions containing metallic ions above and below hydrogen in
the electromotive series on dental caries in the Sy rian hamster. J. Am. Dent. Assoc. 57: 796-800.
Witzmann, F. A.; Daggett, D. A.; Fultz, C. D.; Nelson, S. A.; Wright, L. S.; Kornguth, S. E.; Siegel, F. L. (1998)

Glutathione S -transferases: two-dimensional electrophoretic protein markers of lead exposure.
Electrophoresis 19: 1332-1335.
Wolin, M. S. (2000) Interactions of oxidants with vasc ular signaling systems. Arterioscler. Thromb. Vasc. Biol.

20: 1430-1442. Wood, N.; Bourque, K.; Donaldson, D. D.; Collins, M.; Vercelli, D.; Goldman, S. J.; Kasaian, M. T. (2004) IL-21
effects on human IgE production in response to IL-4 or IL-13. Cell. Immunol. 231: 133-145.

Wo ź niak, K.; Blasiak, J. (2003) In vitr o genotoxicity of lead acetate: induc tion of single and double DNA strand
breaks and DNA-protein cross-links. Mutat. Res. 535: 127-139.
Wright, R. O.; Hu, H.; Maher, T. J.; Amarasiriwardena, C.; Chaiyakul, P.; Woolf, A. D.; Shannon, M. W. (1998) Effect of iron deficiency anemia on lead distribution after intravenous dosing in rats. Toxicol. Ind. Health

14: 547-551.
Wu, W.; Rinaldi, L.; Fortner, K. A.; Russell, J. Q.; Tschoo p, J.; Irvin, C.; Budd, R. C. (2004) Cellular FLIP long
form-transgenic mice manifest a Th2 cytokine bias and enhanced allergic airway inflammation. J. Immunol.

172: 4724-4732.

# AX5-235 Xie, Y.; Chiba, M.; Shinohara, A.; Watanabe, H.; Inaba, Y. (1998) Studies on lead-binding protein and interaction
between lead and selenium in the human erythrocytes. Ind. Health 36: 234-239.
Xie, L.; Gao, Q.; Xu, H. (2003) Ameliorative effect of L 

# -methionine on Pb-exposed mice. Biol. Trace Elem. Res.

93: 227-236.

Xie, H.; Wise, S. S.; Holmes, A. L.; Xu, B, Wakeman, T. P.; Pelsue, S. C.; Singh, N. P.; Wise, J. P., Sr. (2005) Carcinogenic lead chromate induces DNA double-s trand breaks in human lung cells. Mutat. Res.

586: 160-172.
Xu, J. A.; Wise, J. P.; Patierno, S. R. (1992) DNA dama ge induced by carcinogenic lead chromate particles in

cultured mammalian cells. Mutat. Res. 280: 129-136.
Xu, D. X.; Shen, H. M.; Zhu, Q. X.; Chua, L.;, Wang, Q. N.; Chia, S. E.; Ong, C. N. (2003) The associations among
semen quality, oxidative DNA damage in human spermatozoa and concentrations of cadmium, lead and selenium in seminal plasma. Mutat. Res. 534: 155-163.
Yamamoto, C.; Miyamoto, A.; Sakamoto, M.; Kaji, T.; Kozuka, H. (1997) Lead perturbs the regulation of spontaneous release of tissue plasminogen activator and plasminogen activator inhibitor-1 from vascular
smooth muscle cells and fibroblasts in culture. Toxicology 117: 153-161.
Yánez, L.; García-Nieto, E.; Rojas, E.; Carrizales, L.; Mejía, J.; Calder ón, J.; Razo, I.; Díaz-Barriga, F. (2003) DNA damage in blood cells from children exposed to arsenic and lead in a mining area. Environ. Res.

93: 231-240. Yang, Y.; Ma, Y.; Ni, L.; Zhao, S.; Li, L.; Zhang, J.; Fan, M.; Liang, C.; Cao, J.; Xu, L. (2003) Lead exposure through gestation-only caused long-term learning/memory deficits in young adult offspring. Exp. Neurol.

184: 489-495. Ye, S.-H. (1993) Hypoxanthine phosphoribosyl transferase assay of lead mutagenicity on keratinocytes. Zhongguo

Yaoli Xuebao 14: 145-147.
Youssef, S. A. H. (1996) Effect of subclinical lead toxicity on the immune response of chickens to Newcastle's

disease virus vaccine. Res. Vet. Sci. 60: 13-16. Yu, S. Y.; Mizinga, K. M.; Nonavinakere, V. K.; Soliman, K. F. (1996) Decreased endurance to cold water
swimming and delayed sexual maturity in the rat fo llowing neonatal lead exposure. Toxicol. Lett.

85: 135-141. Yücesoy, B.; Turhan, A.; Üre, M.; İ mir, T.; Karakaya, A. (1997) Simultaneou s effects of lead and cadmium on NK
cell activity and some phenotypic parameters. Immunopharmacol. Immunotoxicol. 19: 339-348.
Yun, S.-W.; Lannert, H.; Hoyer, S. (20 00a) Chronic exposure to low-level lead impairs learning ability during aging and energy metabolism in aged rat brain. Arch. Gerontol. Geriatr. 30: 199-213.

Yun, S. W.; Gartner, U.; Arendt, T.; Ho yer, S. (2000b) Increase in vulnerability of middle-aged rat brain to lead by cerebral energy depletion. Brain Res. Bull. 52: 371-378.
Zareba, G.; Chmielnicka, J. (1992) Disturbances in heme biosynthesis in rabbits after administration per os of low

doses of tin or lead. Biol. Trace Elem. Res. 34: 115-122.
Zawia, N. H.; Basha, M. R. (2005) Environmental risk fa ctors and the developmental basis for Alzheimer's disease.

Rev. Neurosci. 16: 325-337.
Zelikoff, J. T.; Li, J. H.; Hartwig, A.; Wang, X. W.; Cost a, M.; Rossman, T. G. (1988) Genetic toxicology of lead compounds. Carcinogenesis 9: 1727-1732.
Zelikoff, J. T.; Parsons, E.; Schlesinger, R. B. (1993) Inhalation of particulate lead oxide disrupts pulmonary
macrophage-mediated functions important for host defense and tumor surveillance in the lung. Environ.

Res. 62: 207-222. Zenick, H.; Rodriquez, W.; Ward, J.; Elkington, B. (1979) Deficits in fixed-interval performance following prenatal
and postnatal lead exposure. Dev. Psychobiol. 12: 509-514. Zhao, W.-F.; Ruan, D.-Y.; Xy, Y.-Z.; Chen, J.-T.; Wang, M. ; Ge, S.-Y. (1999) The effects of chronic lead exposure
on long-term depression in area CA1 and dentate gyrus of rat hippocampus in vitro. Brain Res.

818: 153-159. Zhao, Z. Y.; Li, R.; Sun, L.; Li, Z. Y.; Yang, R. L. (2004) Effect of lead exposure on the immune function of
lymphocytes and erythrocytes. in preschool children. J. Zhejiang Univ. Sci. 5(8): 1001-1004.
Zheng, W.; Shen, H.; Blaner, W. S.; Zhao, Q.; Ren, X.; Graziano, J. H. (1996) Chronic lead exposure alters transthyretin concentration in rat cerebrospinal fluid: the role of the choroid plexus. Toxicol. Appl.

Pharmacol. 139: 445-450.
Zhou, M.; Suszkiw, J. B. (2004) Nicotin e attenuates spatial learning deficits induced in the rat by perinatal lead
exposure. Brain Res. 999: 142-147.

# AX5-236 Zhou, J.; Xu, Y.-H.; Chang, H.-F. (1985) The effects of lead ion on immune function of rabbit alveolar
macrophages: quantitation of immune phagocytosis and Rosette Formation by 51Cr in vitro . Toxicol. Appl.

Pharmacol. 78: 484-487.
Zhou, X. J.; Vaziri, N. D.; Wang, X. Q.; Silva, F. G.; Laszik, Z. (2002) Nitric oxide synthase expression in
hypertension induced by inhibition of glutathione synthase. J. Pharmacol. Exp. Ther. 300: 762-767. Zimmermann, L.; Pages, N.; Antebi, H.; Hafi, A.; Boudene, C. ; Alcindor, L. G. (1993) L ead effect on the oxidation
resistance of erythrocyte membrane in rat triton- induced hyperlipidemia. Biol. Trace Elem. Res.

38: 311-318.

Zuscik, M. J.; Pateder, D. B.; Puzas, J. E.; Schwarz, E. M.; Rosier, R. N.; O'Keefe, R. J. (2002) Lead alters
parathyroid hormone-related peptide and transforming growth factor- β 1 effects and AP-1 and NF- κ B signaling in chondrocytes. J. Orthop. Res. 20: 811-818.

# October 2006

EPA/600/R-05/144bF



# Air Quality Criteria for Lead

Volume II of II

# EPA/600/R-05/144bF

October 2006



# Air Quality Criteria for Lead

Volume II

National Center for Environmental Assessment-RTP Division
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, NC

# II-iii PREFACE

National Ambient Air Quality Standards (NAAQS ) are promulgated by the United States

Environmental Protection Agency (EPA) to meet requirements set forth in Sections 108 and 109

of the U.S. Clean Air Act. Those two Clean Air Act sections require the EPA Administrator

(1) to list widespread air pollutants that reasonabl y may be expected to endanger public health or

welfare; (2) to issue air qualit y criteria for them that assess the latest available scientific

information on nature and effects of ambient e xposure to them; (3) to set “primary” NAAQS to

protect human health with ade quate margin of safety and to set “secondary” NAAQS to protect

against welfare effects (e.g., effects on vegeta tion, ecosystems, visibility, climate, manmade

materials, etc); and (5) to peri odically review and revise, as appropriate, the criteria and NAAQS

for a given listed pollutant or class of pollutants.

Lead was first listed in the mid-1970’s as a “criteria air pollutant” requiring NAAQS

regulation. The scientific inform ation pertinent to Pb NAAQS de velopment available at the time

was assessed in the EPA document Air Quality Criteria for Lead ; published in 1977. Based on

the scientific assessments contained in that 1977 lead air quality criteria document (1977 Lead

AQCD), EPA established a 1.5 μg/m 3 

# (maximum quarterly calendar average) Pb NAAQS in

1978.

To meet Clean Air Act requirements noted above for periodic review of criteria and

NAAQS, new scientific information published si nce the 1977 Lead AQCD was later assessed in

a revised Lead AQCD and Addendum published in 1986 and in a Supplement to the 1986

AQCD/Addendum published by EPA in 1990. A 1990 L ead Staff Paper, prepared by EPA’s

Office of Air Quality Planning and Standards (OPQPS), drew upon key findings and conclusions

from the 1986 Lead AQCD/Addendum and 1990 Supplement (as well as other OAQPSsponsored lead exposure/risk analyses) in posing options for the EPA Administrator to consider

with regard to possible revision of the Pb NAAQS . However, EPA chose not to revise the Pb

NAAQS at that time. Rather , as part of implementing a broad 1991 U.S. EPA Strategy for

Reducing Lead Exposure, the Agency focused primarily on regulatory and remedial clean-up

efforts to reduce Pb exposure from a variety of non-air sources that posed more extensive public

health risks, as well as other actions to reduce air emissions.

# II-iv The purpose of this revised Lead AQCD is to critically assess the latest scientific

information that has become available sin ce the literature asse ssed in the 1986 Lead

AQCD/Addendum and 1990 Supplement, with the main focus being on pertinent new

information useful in evaluating health and enviro nmental effects of ambien t air lead exposures.

This includes discussion in this document of information rega rding: the nature, sources,

distribution, measurement, and c oncentrations of lead in the environment; multimedia lead

exposure (via air, food, water, et c.) and biokinetic modeling of c ontributions of such exposures

to concentrations of lead in brain, kidney, a nd other tissues (e.g., blood and bone concentrations,

as key indices of lead exposure).; characterization of l ead health effects and associated exposureresponse relationships; and delineation of environmen tal (ecological) effects of lead. This final

version of the revised Lead AQCD mainly assesses pertinent literature published or accepted for

publication through December 2005.

The First External Review Draft (dated December 2005) of the revised Lead AQCD

underwent public comment and was reviewed by the Clean Air Scientific Advisory Committee

(CASAC) at a public meeting held in Durham , NC on February 28-March 1, 2006. The public

comments and CASAC recommendations receiv ed were taken into account in making

appropriate revisions and incorporating them in to a Second External Review Draft (dated May,

2006) which was released for further public co mment and CASAC review at a public meeting

held June 28-29, 2006. In addition, still further revised drafts of the Integrative Synthesis

chapter and the Executive Summary were then issued and discussed during an August 15, 2006

CASAC teleconference call. Public commen ts and CASAC advice received on these latter

materials, as well as Second External Review Draf t materials, were taken into account in making

and incorporating further revisions into this fi nal version of this Lead AQCD, which is being

issued to meet an October 1, 2006 court-ordered d eadline. Evaluations c ontained in the present

document provide inputs to an associated Lead Staff Paper prepared by EPA’s Office of Air

Quality Planning and Standards (OAQPS), which poses options for consideration by the EPA

Administrator with regard to proposal and, ul timately, promulgation of decisions on potential

retention or revision, as appropriate, of the current Pb NAAQS.

Preparation of this document has been coordi nated by staff of EPA’s National Center for

Environmental Assessment in Research Triangl e Park (NCEA-RTP). NCEA-RTP scientific

staff, together with experts from academia, contri buted to writing of docum ent chapters. Earlier

# II-v drafts of document materials were reviewed by scientists from other EPA units and by non-EPA

experts in several public peer consultation workshops held by EPA in July/August 2005.

NCEA acknowledges the valuab le contributions provided by authors, contributors, and

reviewers and the diligence of its staff and contractors in the prep aration of this document. The

constructive comments provided by public comment ers and CASAC that served as valuable

inputs contributing to improved scientific and editorial quality of the document are also

acknowledged by NCEA.

DISCLAIMER

Mention of trade names or commercial produc ts in this document does not constitute

endorsement or recommendation for use.

.

# II-vi 

# Air Quality Criteria for Lead (Second External Review Draft)

VOLUME I

EXECUTIVE SUMMARY .........................................................................................................E-1

1. INTRODUCTION ........................................................................................................... 1-1

2. CHEMISTRY, SOURCES, AN D TRANSPORT OF LEAD.......................................... 2-1

3. ROUTES OF HUMAN EXPOSURE TO LEAD AND OBSERVED

ENVIRONMENTAL CONCENTRATIONS.................................................................. 3-1

4. TOXICOKINETICS, BIOLOGICAL MARKERS, AND MODELS OF LEAD

BURDEN IN HUMANS.................................................................................................. 4-1

5. TOXICOLOGICAL EFFECTS OF LEAD IN LABORATORY ANIMALS

AND IN VITRO TEST SYSTEMS................................................................................. 5-1

6. EPIDEMIOLOGIC STUDIES OF HUMAN HEALTH EFFECTS

ASSOCIATED WITH LEAD EXPOSURE.................................................................... 6-1

7. ENVIRONMENTAL EFFECTS OF LEAD ................................................................... 7-1

8. INTEGRATIVE SYNTHESIS OF LEAD EXPOSURE/HEALTH

EFFECTS INFORMATION............................................................................................ 8-1



# VOLUME II

CHAPTER 4 ANNEX (TOXICOKINETICS , BIOLOGICAL MARKERS, AND
MODELS OF LEAD BURDEN IN HUMANS)..................................................... AX4-1

CHAPTER 5 ANNEX (TOXICOLOGICAL EFFECTS OF LEAD IN
LABORATORY ANIMALS AND IN VITRO TEST SYSTEMS)................ AX5-1

CHAPTER 6 ANNEX (EPIDEMIOLOGIC STUDIES OF HUMAN HEALTH

EFFECTS ASSOCIATED WITH LEAD EXPOSURE)................................. AX6-1

CHAPTER 7 ANNEX (ENVIRONMENTA L EFFECTS OF LEAD).................................. AX7-1

# II-vii Table of Contents

Page

PREFACE........................................................................................................................ ..............iii

DISCLAIMER ................................................................................................................................ v

List of Tables ................................................................................................................. ..............viii

Authors, Contributors, and Reviewers........................................................................................... xi
U.S. Environmental Protection Agency Project Team for Development
of Air Quality Criteria for Lead.......................................................................................... ... xvii
U.S. Environmental Protection Agency Science Advisory Board (SAB)

Staff Office Clean Air Scient ific Advisory Committee (CASAC)......................................... xix
Abbreviations and Acronyms ..................................................................................................... . xxi

AX6. CHAPTER 6 ANNEX (EPIDEMI OLOGIC STUDIES OF HUMAN

HEALTH EFFECTS ASSOCIATED WITH LEAD EXPOSURE ......................... AX6-1

ANNEX TABLES AX6-2 ....................................................................................... AX6-2

ANNEX TABLES AX6-3 ..................................................................................... AX6-29

ANNEX TABLES AX6-4 ..................................................................................... AX6-69

ANNEX TABLES AX6-5 ................................................................................... AX6-129

ANNEX TABLES AX6-6 ................................................................................... AX6-168

ANNEX TABLES AX6-7 ................................................................................... AX6-182

ANNEX TABLES AX6-8 ................................................................................... AX6-206

ANNEX TABLES AX6-9 ................................................................................... AX6-220

REFERENCES .................................................................................................... AX6-260

# II-viii List of Tables

Number Page

AX6-2.1 Prospective Longitudinal Cohort St udies of Neurocognitive Ability in

Children............................................................................................................ AX6-3

AX6-2.2 Meta- and Pooled-Analyses of Neur ocognitive Ability in Children ............... AX6-9

AX6-2.3 Cross-Sectional Studies of Neur ocognitive Ability in Children.................... AX6-11

AX6-2.4 Effects of Lead on Academic Achievement in Children ............................... AX6-14

AX6-2.5 Effects of Lead on Specific Cognitive Abilities in Children —

Attention/Executive Functions, Learni ng, and Visual-spatial Skills............. AX6-17

AX6-2.6 Effects of Lead on Disturban ces in Behavior, Mood, and Social

Conduct in Children....................................................................................... AX6-19

AX6-2.7 Effects of Lead on Sensor y Acuities in Children........................................... AX6-23

AX6-2.8 Effects of Lead on Neuromot or Function in Children................................... AX6-24

AX6-2.9 Effects of Lead on Direct Measures of Brain Anatomical
Development and Activity in Children.......................................................... AX6-25

AX6-2.10 Reversibility of Lead-relate d Deficits in Children......................................... AX6-27

AX6-3.1 Neurobehavioral Effects A ssociated with Environmental
Lead Exposure in Adults................................................................................ AX6-30

AX6-3.2 Symptoms Associated with Occupa tional Lead Exposure in Adults............. AX6-33

AX6-3.3 Neurobehavioral Effects Asso ciated with Occupational Lead
Exposure in Adults......................................................................................... AX6-36

AX6-3.4 Meta-analyses of Neurobehavi oral Effects with Occupational
Lead Exposure in Adults................................................................................ AX6-49

AX6-3.5 Neurophysiological Function and Occupational Lead
Exposure in Adults......................................................................................... AX6-51

AX6-3.6 Evoked Potentials and Occupational Lead Exposure in Adults..................... AX6-56

AX6-3.7 Postural Stability, Autonomi c Testing, Electroencephalogram,
Hearing Thresholds, and Occupational Lead Exposure in Adults................. AX6-59

# II-ix List of Tables
(cont’d)

Number Page

AX6-3.8 Occupational Exposure to Organolead and Inorganic Lead in Adults .......... AX6-63

AX6-3.9 Other Neurological Outcomes Associat ed with Lead Exposure in Adults.... AX6-66

AX6-4.1 Renal Effects of Lead in the General Population........................................... AX6-70

AX6-4.2 Renal Effects of Lead in the Occupational Population.................................. AX6-81

AX6-4.3 Renal Effects of Lead in the Patient Population .......................................... AX6-104

AX6-4.4 Renal Effects of Lead on Mortality ............................................................. AX6-120

AX6-4.5 Renal Effects of Lead in Children ............................................................... AX6-122

AX6-5.1 Effects of Lead on Blood Pr essure and Hypertension ................................. AX6-130

AX6-5.2 Effects of Lead on Card iovascular Morbidity ............................................. AX6-159

AX6-5.3 Effects of Lead on Cardiovascular Mortality............................................... AX6-162

AX6-5.4 Cardiovascular Effects of Lead on Children................................................ AX6-166

AX6-6.1 Placental Transfer of Lead from Mother to Fetus........................................ AX6-169

AX6-6.2 Lead Exposure and Male Reproduction: Semen Quality............................ AX6-174

AX6-6.3 Lead Exposure and Male Reproduc tion: Time to Pregnancy ..................... AX6-178

AX6-6.4 Lead Exposure and Male Reproduction: Reproductive History................. AX6-180

AX6-7.1 Recent Studies of Lead Exposure and Genotoxicity.................................... AX6-183

AX6-7.2 Key Occupational Studies of Lead Exposure and Cancer ........................... AX6-186

AX6-7.3 Key Studies of Lead Exposure and Ca ncer in the General Population........ AX6-192

AX6-7.4 Other Studies of Lead Exposure and Cancer ............................................... AX6-194

AX6-8.1 Effects of Lead on Immune Function in Children ....................................... AX6-207

AX6-8.2 Effects of Lead on Immune Function in Adults........................................... AX6-211

# II-x List of Tables
(cont’d)

Number Page

AX6-9.1 Effects of Lead on Biochemi cal Effects in Children ................................... AX6-221

AX6-9.2 Effects of Lead on Bioche mical Effects in Adults....................................... AX6-223

AX6-9.3 Effects of Lead on Hematopoietic System in Children ............................... AX6-231

AX6-9.4 Effects of Lead on Hematopoi etic System in Adults................................... AX6-234

AX6-9.5 Effects of Lead on the Endocrine System in Children................................. AX6-241

AX6-9.6 Effects of Lead on the Endoc rine System in Adults.................................... AX6-243

AX6-9.7 Effects of Lead on the Hepatic System in Children and Adults .................. AX6-251

AX6-9.8 Effects of Lead on the Ga strointestinal System........................................... AX6-253

AX6-9.9 Effects of Lead on Bone and Teeth in Children and Adults........................ AX6-255

AX6-9.10 Effects of Lead on Ocular H ealth in Children and Adults........................... AX6-258

# II-xi Authors, Contributors, and Reviewers

CHAPTER 4 ANNEX (TOXICOKINETIC S, BIOLOGICAL MARKERS, AND
MODELS OF LEAD BURDEN IN HUMANS)

Chapter Managers/Editors

Dr. James Brown—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Principal Authors

Dr. Brian Gulson—Graduate School of the Environment, Macquarie University
Sydney, NSW 2109, Australia

Contributors and Reviewers

Dr. Lester D. Grant—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. John Vandenberg—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

CHAPTER 5 ANNEX (TOXICOLOGICAL EFFECTS OF LEAD IN HUMANS
AND LABORATORY ANIMALS)

Chapter Managers/Editors

Dr. Anuradha Mudipalli—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Srikanth Nadadur—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Lori White—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

# II-xii Authors, Contributors, and Reviewers
(cont’d)

Principal Authors

Dr. Anuradha Mudipalli—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Stephen Lasley—Dept. of Biomedical and Ther apeutic Sciences, Univ. of Illinois College of

Medicine, PO Box 1649, Peoria, IL 61656

Dr. Lori White—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Gary Diamond— Syracuse Research Cor poration, 8191 Cedar Street, Akron, NY 14001

Dr. N.D. Vaziri—Division of Nephrology and Hype rtension, University of California – Irvine
Medical Center, 101, The City Drive, Bldg 53, Room #125. Orange, CA 92868

Dr. John Pierce Wise, Sr.—Maine Center fo r Toxicology and Environmental Health,
Department of Applied Medical Sciences, 96 Falmouth Street, PO Box 9300, Portland, ME

04104-9300

Dr. Harvey C. Gonick—David Geffen School of Medicine, University of California at
Los Angeles, 201 Tavistock Ave, Los Angeles, CA 90049

Dr. Gene E. Watson—University of Rochester Medical Center, Box 705, Rochester, NY 14642

Dr. Rodney Dietert—Institute for Comparativ e and Environmental Toxicology, College of
Veterinary Medicine, Cornel l University, Ithaca, NY 14853

Contributors and Reviewers

Dr. Lester D. Grant—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Paul Reinhart—Nationa l Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Michael Davis—Nationa l Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. David A. Lawrence—Dept of Environmental and Clinical Immunology, Empire State Plaza
P.O. Box 509, Albany, NY 12201

# II-xiii Authors, Contributors, and Reviewers
(cont’d)

Contributors and Reviewers
(cont’d)

Dr. Michael J. McCabe, Jr.—Dept of Environm ental Medicine, University of Rochester,

575 Elmwood Avenue, Rochester, NY 14642

Dr. Theodore I. Lidsky—New York State Inst itute for Basic Research, 1050 Forest RD,

Staten Island, NY 10314

Dr. Mark H. Follansbee—Syracuse Research Corporation, 8191 Cedar St. Akron, NY 14001

Dr. William K. Boyes—National Health and En vironmental Effects Research Laboratory,
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Philip J. Bushnell—National Health and Environmental Effects Research Laboratory,
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Ms. Beth Hassett-Sipple—Office of Air Quality Planning and Standards, U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711

Dr. Zachary Pekar—Office of Air Quality Pla nning and Standards, U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711

Dr. John Vandenberg—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

CHAPTER 6 ANNEX (EPIDEMIOLOGICA L STUDIES OF AMBIENT LEAD
EXPOSURE EFFECTS)

Chapter Managers/Editors

Dr. Jee Young Kim—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Dennis Kotchmar—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. David Svendsgaard—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

# II-xiv Authors, Contributors, and Reviewers
(cont’d)

Principal Authors

Dr. David Bellinger—Children’s Hospital, Fa rley Basement, Box 127, 300 Longwood Avenue,

Boston, MA 02115

Dr. Margit Bleecker—Center for Occupational and Environmental Neurology, 2 Hamill Road,

Suite 225, Baltimore, MD 21210

Dr. Gary Diamond— Syracuse Resear ch Corporation, 8191 Cedar Street.

Akron, NY 14001

Dr. Kim Dietrich—University of Cincinnati College of Medicine, 3223 Eden Avenue,
Kettering Laboratory, Room G31, Cincinnati, OH 45267

Dr. Pam Factor-Litvak—Columbia University Mailman School of Public Health,

722 West 168th Street, Ro om 1614, New York, NY 10032

Dr. Vic Hasselblad—Duke University Medical Center, Durham, NC 27713

Dr. Stephen J. Rothenberg—CINVESTAV-IPN, Mé rida, Yucatán, México & National Institute

of Public Health, Cuernavaca, Morelos, Mexico

Dr. Neal Simonsen—Louisiana State University Hea lth Sciences Center, School of Public Health & Stanley S Scott Cancer Center, 1600 Cana l Street, Suite 800, New Orleans, LA 70112

Dr. Kyle Steenland—Rollins School of Public Health, Emory University, 1518 Clifton Road,

Room 268, Atlanta, GA 30322

Dr. Virginia Weaver—Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe

Street, Room 7041, Baltimore, MD 21205

Contributors and Reviewers

Dr. J. Michael Davis—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Lester D. Grant—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Kazuhiko Ito—Nelson Institute of Environmental Medicine, Ne w York University School of

Medicine, Tuxedo, NY 10987

# II-xv Authors, Contributors, and Reviewers
(cont’d)

Contributors and Reviewers
(cont’d)

Dr. Kathryn Mahaffey—Office of Prevention, Pesticides and Toxic Substances,
U.S. Environmental Protection Agency, Washington, DC 20460

Dr. Karen Martin—Office of Air Quality Pl anning and Standards, U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711

Dr. Zachary Pekar—Office of Air Quality Pla nning and Standards, U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711

Ms. Beth Hassett-Sipple—Office of Air Quality Planning and Standards, U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711

Dr. John Vandenberg—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

CHAPTER 7 ANNEX (ENVIRONME NTAL EFFECTS OF LEAD)

Chapter Manager/Editor

Dr. Timothy Lewis—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Principle Authors

Dr. Ruth Hull—Cantox Environmental Inc., 190 0 Minnesota Court, Suite 130, Mississauga,

Ontario, L5N 3C9 Canada

Dr. James Kaste—Department of Earth Scienc es, Dartmouth College, 352 Main Street,

Hanover, NH 03755

Dr. John Drexler—Department of Geologica l Sciences, University of Colorado,
1216 Gillespie Drive, Boulder, CO 80305

Dr. Chris Johnson—Department of Civil and Envir onmental Engineering, Syracuse University,
365 Link Hall, Syracuse, NY 13244

Dr. William Stubblefield—Parametrix, Inc. 33972 Texas St. SW, Albany, OR 97321

# II-xvi Authors, Contributors, and Reviewers
(cont’d)

Principle Authors
(cont’d)

Dr. Dwayne Moore—Cantox Environmental, Inc., 1550A Laperriere Avenue, Suite 103,

Ottawa, Ontario, K1Z 7T2 Canada

Dr. David Mayfield—Parametrix, Inc., 411 108th Ave NE, Suite 1800, Bellevue, WA 98004

Dr. Barbara Southworth—Menzie-Cura & Associ ates, Inc., 8 Winchester Place, Suite 202,

Winchester, MA 01890

Dr. Katherine Von Stackleberg—Menzie-Cura & Associates, Inc., 8 Winchester Place,

Suite 202, Winchester, MA 01890

Contributors and Reviewers

Dr. Jerome Nriagu—Department of Environmenta l Health Sciences, 109 South Observatory,
University of Michigan, Ann Arbor, MI 48109

Dr. Judith Weis—Department of Biol ogy, Rutgers University, Newark, NJ 07102

Dr. Sharon Harper—National Exposure Research Laboratory (D205-05), U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711

Dr. Karen Bradham—National Research Exposur e Laboratory (D205-05), U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711

Dr. Ginger Tennant—Office of Air Quality Plan ning and Standards, U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711

Ms. Gail Lacey—Office of Air Quality Planning a nd Standards, U.S. Environmental Protection
Agency, Research Triangle Park, NC 27711

Dr. John Vandenberg—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

# II-xvii U.S. Environmental Protection Agency Project Team

for Development of Air Quality Criteria for Lead

Executive Direction

Dr. Lester D. Grant (Director)—National Cent er for Environmental Assessment-RTP Division,
(B243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Scientific Staff

Dr. Lori White (Lead Team Leader)—Nati onal Center for Environmental Assessment
(B243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. James S. Brown—National Center fo r Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Robert Elias—Nationa l Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Re search Triangle Park, NC 27711 (Retired)

Dr. Brooke Hemming—National Center for Environmental Assessment (B243-01), U.S.
Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Jee Young Kim—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Dennis Kotchmar—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Timothy Lewis—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Anuradha Muldipalli—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Srikanth Nadadur—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Paul Reinhart—Nationa l Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Mary Ross— National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. David Svendsgaard—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

# II-xviii U.S. Environmental Protection Agency Project Team

for Development of Air Quality Criteria for Lead
(cont’d)

Technical Support Staff

Mr. Douglas B. Fennell—Technical Information Sp ecialist, National Center for Environmental
Assessment (B243-01), U.S. Environmental Prot ection Agency, Research Triangle Park, NC
27711 (Retired)

Ms. Emily R. Lee—Management Analyst, Natio nal Center for Environmental Assessment
(B243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Ms. Diane H. Ray—Program Specialist, Natio nal Center for Environmental Assessment
(B243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Ms. Donna Wicker—Administrative Officer, National Center for Environmental Assessment
(B243-01), U.S. Environmental Protection Agenc y, Research Triangle Park, NC 27711 (Retired)

Mr. Richard Wilson—Clerk, National Center fo r Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Document Production Staff

Ms. Carolyn T. Perry—Task Order Manager, Com puter Sciences Corpor ation, 2803 Slater Road,

Suite 220, Morrisville, NC 27560

Mr. John A. Bennett—Technical Information Sp ecialist, Library Asso ciates of Maryland,

11820 Parklawn Drive, Suite 400, Rockville, MD 20852

Mr. William Ellis—Records Management Technici an, InfoPro, Inc., 8200 Greensboro Drive,

Suite 1450, McLean, VA 22102

Ms. Sandra L. Hughey—Technical Information Sp ecialist, Library Associates of Maryland,

11820 Parklawn Drive, Suite 400, Rockville, MD 20852

Dr. Barbara Liljequist—Technical Editor, Comp uter Sciences Corporation, 2803 Slater Road,

Suite 220, Morrisville, NC 27560

Ms. Michelle Partridge-Doerr—Publications/Gra phics Specialist, TEK Systems, 1201 Edwards
Mill Road, Suite 201, Raleigh, NC 27607

Mr. Carlton Witherspoon—Graphic Artist, Comput er Sciences Corporation, 2803 Slater Road,

Suite 220, Morrisville, NC 27560

# II-xix U.S. Environmental Protection Agency
Science Advisory Board (SAB) Staff Office

Clean Air Scientific Advi sory Committee (CASAC)

Chair

Dr. Rogene Henderson*—Scientist Emeritus, Lovelace Respiratory Research Institute,
Albuquerque, NM

Members

Dr. Joshua Cohen—Faculty, Center for the Evaluati on of Value and Risk, Institute for Clinical
Research and Health Policy Studies, Tuft s New England Medical Center, Boston, MA

Dr. Deborah Cory-Slechta—Director, University of Medicine and Dentistry of New Jersey and
Rutgers State University, Piscataway, NJ

Dr. Ellis Cowling*—University Distinguished Professor-at-Large, North Carolina State
University, Colleges of Natural Resources and Agriculture and Life Sciences, North Carolina
State University, Raleigh, NC

Dr. James D. Crapo [M.D.]*—Professor, Departme nt of Medicine, National Jewish Medical and

Research Center, Denver, CO

Dr. Bruce Fowler—Assistant Director for Scien ce, Division of Toxicology and Environmental Medicine, Office of the Director, Agency for Toxic Substances and Disease Registry, U.S.

Centers for Disease Control and Pr evention (ATSDR/CDC), Chamblee, GA

Dr. Andrew Friedland—Professo r and Chair, Environmental Studies Program, Dartmouth
College, Hanover, NH

Dr. Robert Goyer [M.D.]—Emeritu s Professor of Pathology, Faculty of Medicine, University of
Western Ontario (Canada), Chapel Hill, NC

Mr. Sean Hays—President, Summ it Toxicology, Allenspark, CO

Dr. Bruce Lanphear [M.D.]—Sloan Professor of Children’s Environmental Health, and the

Director of the Cincinnati Ch ildren’s Environmental Health Ce nter at Cincinnati Children’s
Hospital Medical Center and the Univer sity of Cincinnati, Cincinnati, OH

Dr. Samuel Luoma—Senior Research Hydr ologist, U.S. Geological Survey (USGS),

Menlo Park, CA

# II-xx U.S. Environmental Protection Agency
Science Advisory Board (SAB) Staff Office

Clean Air Scientific Advi sory Committee (CASAC)
(cont’d)

Members
(cont’d)

Dr. Frederick J. Miller*—Consultant, Cary, NC

Dr. Paul Mushak—Principal, PB A ssociates, and Visiting Professor, Albert Einstein College of
Medicine (New York, NY), Durham, NC

Dr. Michael Newman—Professor of Marine Science, School of Marine Sciences, Virginia
Institute of Marine Science, College of William & Mary, Gloucester Point, VA

Mr. Richard L. Poirot*—Environmental Analyst, Air Pollution Control Di vision, Department of
Environmental Conservation, Vermont Agency of Natural Resources, Waterbury, VT

Dr. Michael Rabinowitz—Geochemist, Marine Biological Laboratory, Woods Hole, MA

Dr. Joel Schwartz—Professor, Environmental H ealth, Harvard University School of Public

Health, Boston, MA

Dr. Frank Speizer [M.D.]*—Edward Kass Prof essor of Medicine, Channing Laboratory,

Harvard Medical School, Boston, MA

Dr. Ian von Lindern—Senior Scientist, TerraG raphics Environmenta l Engineering, Inc.,

Moscow, ID

Dr. Barbara Zielinska*—Research Professor, Divi sion of Atmospheric Science, Desert Research

Institute, Reno, NV

SCIENCE ADVISORY BOARD STAFF

Mr. Fred Butterfield—CASAC Designated Fede ral Officer, 1200 Pennsyl vania Avenue, N.W.,
Washington, DC, 20460, Phone: 202-343-9994, Fax: 202-233-0643 (butterfield.fred@epa.gov ) (Physical/Courier/FedEx Address: Fred A. Butterf ield, III, EPA Science Advisory Board Staff
Office (Mail Code 1400F), Woodies Building, 1025 F Street, N.W., Room 3604, Washington,
DC 20004, Telephone: 202-343-9994)

*Members of the statutory Clean Air Scientific Advisory Committee (CASAC) appointed by the

U.S. EPA Administrator

# II-xxi Abbreviations and Acronyms

α FGF α -fibroblast growth factor

AA arachidonic acid

AAL active avoidance learning

AAS atomic absorption spectroscopy

ABA β -aminoisobutyric acid

ACBP Achenbach Child Behavior Profile

ACE angiotensin converting enzyme

ACh acetylcholine

AChE acetylcholinesterase

ACR acute-chronic ratio

AD adult

ADC analog digital converter

ADP adenosine diphosphate

AE anion exchange

AEA N -arachidonylethanolamine

AFC antibody forming cells

2-AG 2-arachidonylglycerol

A horizon uppermost layer of soil (litter and humus)

AHR aryl hydrocarbon receptor

AI angiotensin I

ALA ∗ -aminolevulinic acid

ALAD ∗ -aminolevulinic acid dehydratase

ALAS aminolevulinic acid synthetase

ALAU urinary δ -aminolevulinic acid

ALD aldosterone

ALS amyotrophic lateral sclerosis

ALT alanine aminotransferase

ALWT albumin weight

AMEM Alpha Minimal Essential Medium

AMP adenosine monophosphate

ANCOVA analysis of covariance

ANF atrial natriuretic factor

Ang II angiotensin II

# II-xxii ANOVA analysis of variance

ANP atrial natriuretic peptide

AP alkaline phosphatase

AP-1 activated protein-1

ApoE apolipoprotein E

AQCD Air Quality Criteria Document

Arg arginine

AS52 cells derived from the CHO cell line

ASGP-R aceyl glycoprotein receptor

AST aspartate aminotransferase

ASV anode stripping voltammetry

3-AT 3-aminotriazole; 3-amino triazide

ATP adenosine triphosphate

ATP1A2 sodium-potassium adenosine triphosphase α 2

ATPase adenosine triphosphatase

ATSDR Agency for Toxic Substances and Disease Research

AVCD atrioventricular conduction deficit

AVS acid volatile sulfide

AWQC ambient water quality criteria

∃ beta-coefficient; slope of an equation

∃ FGF ∃ -fibroblast growth factor

17 ∃ –HS 17 ∃ -hydroxysteriod

3 ∃ -HSD 3 ∃ -hydroxysteriod dehydrogenase

17 ∃ -HSDH 17 ∃ -hydroxysteriod dehydrogenase

6 ∃ -OH-cortisol 6- ∃ -hydroxycortisol

B both

BAEP brainstem auditory-evoked potentials

BAER brainstem audito ry-evoked responses

BAF bioaccumulation factor

B cell B lymphocyte

BCFs bioconcentration factors

BCS bovine calf serum

BDNF brain derived neurotrophic factor

BDWT body weight changes

BEI biological exposure index

# II-xxiii BFU-E blood erythroid progenitor

BLL blood lead level

BLM biotic ligand model

BM basement membrane

BMI body mass index

BDNF brain-derived ne urotrophic factor

BOTMP Bruinicks-Oseretsky Test of Motor Proficiency

BP blood pressure

BPb blood lead concentration

BSA bovine serum albumin

BSI Brief Symptom Inventory

BTQ Boston Teacher Questionnaire

BUN blood urea nitrogen

bw, b. wt., BW body weight

C3H10T/12 mouse embryo cell line

C3, C4 complement proteins

CA chromosome aberration

CA3 cornu ammonis 3 region of hippocampus

45 

# Ca calcium-45 radionuclide

Ca-ATP calcium-dependent adenosine triphosphate

Ca-ATPase calcium-dependent adenosine triphosphatase

CaCO 3 

# calcium carbonate

CaEDTA calcium disodium ethylenediaminetetraacetic acid

CAL calcitonin

CaM calmodulin

Ca-Mg-ATPase calcium-magnesium-dependent adenosine triphosphatase

cAMP cyclic adenosinemonophosphate

CaNa 2 

# EDTA calcium disodium ethyl enediaminetetraacetic acid

CANTAB Cambridge Neuropsychologi cal Testing Automated Battery

CAT catalase; Cognitive Abilities Test

CBCL Achenbach Child Behavior Checklist

CBCL-T Total Behavior Problem Score

CBL cumulative blood lead

CBLI cumulative blood lead index

CCB cytochalasin B

# II-xxiv CCD charge-coupled device

CCE Coordination Center for Effects

CCL carbon tetrachloride

CCS cosmic calf serum

C-CV RSA 

# coefficient of component variance of respiratory sinus arrhythmia

Cd cadmium

109 

# Cd cadmium-109 radionuclide

CdU urinary cadmium

CEC cation exchange capacity

CESD, CES-D Center for Epidemio logic Studies Depression (scale)

GFAP glial fibrillary acidic protein

CFU-E colony forming unit blood-er ythroid progenitor (cell count)

CFU-GEMM colony forming unit blood- pluripotent progen itor (cell count)

CFU-GM blood granulocyte/macro phage progenitor (cell count)

cGMP cyclic guanosine-3',5'-monophosphate

ChAT choline acetyltransferase

CHD coronary heart disease

CHO Chinese hamster ovary cell line

CI confidence interval

CLE-SV competitive ligand-exchange/stripping voltammetry

CLRTAP Convention on Long-Range Transboundary of Air Pollution

CLS Cincinnati Lead Study

CMC criterion maximum concentration

CMI cell-mediated immunity

CNS central nervous system

COH cation-osmotic hemolysis

ConA concanavalin A

COR cortisol

CoTx cotreatment

COX-2 cyclooxygenase-2

CP coproporphryn

CPT current perception threshold

cr creatinine

CRAC calcium release activated calcium reflux

CREB cyclic AMP-response element binding protein

# II-xxv CRF chronic renal failure

CRI chronic renal insufficiency

CSF cerebrospinal fluid

CuZn-SOD copper and zinc-dependent superoxide dismutase

CV conduction velocity

CVLT California Verbal Learning Test

CV R-R 

# coefficient of variation of the R-R interval

CYP cytochrome (e.g., CYP1A, CYP-2A6, CYP3A4, CYP450)

CYP3a11 cytochrome P450 3a11

D D-statistic

DA dopamine; dopaminergic

dbcAMP dibutyryl cyclic ad enosine-3',5'-monophosphate

DCV distribution of conduction velocities

DEAE diethylaminoet hyl (chromatography)

DET diffusive equilibrium thin films

DEYO death of young

DFS decayed or filled surfaces, permanent teeth

dfs covariate-adjusted number of caries

DG dentate gyrus

DGT diffusive gradient thin films

DL DL-statistic

DMEM Dulbecco’s Minimal Essential Medium

DMEM/F12 Dulbecco’s Minimal Essential Medium/Ham’s F12

DMFS decayed, missing, or filled surfaces, permanent teeth

DMPS 2,3-dimercaptopropane 1-sulfonate

DMSA 2,3-dimercaptosuccinic acid

DMT Donnan membrane technique

DMTU dimethylthiourea

DNA deoxyribonucleic acid

DO distraction osteogenesis

DOC dissolved organic carbon

DOM dissolved organic carbon

DOPAc 3,4-dihydroxyphenylacetic acid

DPASV differential pulse anod ic stripping voltammetry

dp/dt rate of left ventri cular isovolumetric pressure

# II-xxvi DPPD N

- N -diphenyl- p -phynylene-diamine

DR drinking water

DSA delayed spatial alternation

DTC diethyl dithiocarbomate complex

DTH delayed type hypersensitivity

DTPA diethylenetriaminepentaacetic acid

DTT dithiothreitol

dw dry weight

E embryonic day

E 2 

# estradiol

EBE early biological effect

EBV Epstein-Barr virus

EC European Community

EC 50 

# effect concentration fo r 50% of test population

eCB endocannabinoid

ECG electrocardiogram

Eco-SSL ecological soil screening level

EDS energy dispersive spectrometers

EDTA ethylenediaminetetraacetic acid

EEDQ N -ethoxycarbonyl-2-eth oxy-1,2-dihydroquinone

EEG electroencephalogram

EG egg

EGF epidermal growth factor

EGG effects on eggs

EGPN egg production

EKG electrocardiogram

electro electrophysiological stimulation

EM/CM experimental medium-to-control medium (ratio)

EMEM Eagle’s Minimal Essential Medium

eNOS endothelial nitr ic oxide synthase

EP erythrocyte protoporphyrin

EPA U.S. Environmental Protection Agency

Epi epinephrine

EPMA electron probe microanalysis

EPO erythropoietin

# II-xxvii EPSC excitatory postsynaptic currents

EPT macroinvertebrates from the Ephemeroptera (mayflies),
Plecoptera (stoneflies), and Trichoptera (caddisflies) group

ERG electroretinogram; electroretinographic

ERL effects range – low

ERM effects range – median

EROD ethoxyresorufin- O -deethylase

ESCA electron spectroscopy for chemical analysis

ESRD end-stage renal disease

EST estradiol

ESTH eggshell thinning

ET endothelein; essential tremor

ETOH ethyl alcohol

EXAFS extended X-ray absorption fine structure

EXANES extended X-ray absorption near edge spectroscopy

F F-statistic

F344 Fischer 344 (rat)

FAV final acute value

FBS fetal bovine serum

FCS fetal calf serum

FCV final chronic value

FD food

FEF forced expiratory flow

FEP free erythrocyte protoporphyrin

FERT fertility

FEV 1 

# forced expiratory volume in one second

FGF fibroblast growth factor (e.g., β FGF, α FGF)

FI fixed interval (operant conditioning)

FIAM free ion activity model

FMLP N -formyl-L-methionyl-L-l eucyl-L-phenylalanine

fMRI functional magnetic resonance imaging

FR fixed-ratio operant conditioning

FSH follicle stimulating hormone

FT3 free triiodothyronine

FT4 free thyroxine

# II-xxviii FTES free testosterone

FTII Fagan Test of Infant Intelligence

FTPLM flow-through permeation liquid membranes

FURA-2 1-[6-amino-2-(5-carboxy-2- oxazolyl)-5-benzofuranyloxy]-2-(2-
amino-5-methylphenoxy) ethane- N

, N

, N'

, N' -tetraacetic acid

FVC forced vital capacity

( -GT ( -glutamyl transferase

G gestational day

GABA gamma aminobutyric acid

GAG glycosaminoglycan

G12 CHV79 cells derived from the V79 cell line

GCI General Cognitive Index

GD gestational day

GDP guanosine diphosphate

GEE generalized estimating equations

GFAAS graphite furnace atomic absorption spectroscopy

GFR glomerular filtration rate

GGT ( -glutamyl transferase

GH growth hormone

GI gastrointestinal

GIME-VIP gel integrated microelect rodes combined with voltammetric
in situ profiling

GIS geographic information system

GLU glutamate

GMAV genus mean acute value

GMCV genus mean chronic value

GMP guanosine monophosphate

GMPH general morphology

GnRH gonadotropin releasing hormone

GOT aspartate aminotransferase

GP gross productivity

G6PD, G6PDH glucose-6- phosphate dehydrogenase

GPEI glutathione S -transferase P enhancer element

gp91 phox 

# NAD(P)H oxidase

GPT glutamic-pyruvic transaminase

GPx glutathione peroxidase

# II-xxix GRO growth

GRP78 glucose-regulated protein 78

GSD geometric standard deviation

GSH reduced glutathione

GSIM gill surface interaction model

GSSG glutathione disulfide

GST glutathione- S -transferase

GSTP placental glutathione transferase

GTP guanosine triphosphate

GV gavage

H + 

# acidity

3 

# H hydrogen-3 radionuclide (tritium)

HA humic acid; hydroxyapatite

Hb hemoglobin

HBEF Hubbard Brook Experimenatl Forest

HBSS Hank’s Balanced Salt Solution

HCG; hCG human chorionic gonadotropin

Hct hematocrit

HDL high-density lipopr otein (cholesterol)

HEP habitat evaluation procedure

HET Binghamton heterogeneous stock

HFPLM hollow fiber permeation liquid membranes

Hgb hemoglobin

HGF hepatocyte growth factor

HH hydroxylamine hydrochloride

H-H high-high

HHANES Hispanic Health and Nutrition Examination Survey

H-L high-low

HLA human leukocyte antigen

H-MEM minimum essential medium/nutrient mixture–F12-Ham

HMP hexose monophosphate shunt pathway

HNO 3 

# nitric acid

H 2 

# O 2 

# hydrogen peroxide

HOME Home Observation for Measurement of Environment

HOS TE human osteosarcoma cells

# II-xxx HPLC high-pressure liquid chromatography

H 3 

# PO 4 

# phosphoric acid

HPRT hypoxanthine phosphoribosyltransferase (gene)

HR heart rate

HSI habitat suitability indices

H 2 

# SO 4 

# sulfuric acid

HSPG heparan sulfate proteoglycan

Ht hematocrit

HTC hepatoma cells

hTERT catalytic subunit of human telomerase

HTN hypertension

IBL integrated blood lead index

IBL Η WRAT-R integrated blood lead index Η Wide Range Achievement
Test-Revised (interaction)

ICD International Classification of Diseases

ICP inductively coupled plasma

ICP-AES inductively coupled plas ma atomic emission spectroscopy

ICP-MS, ICPMS inductively coupl ed plasma mass spectrometry

ID-MS isotope dilution mass spectrometry

IFN interferon (e.g., IFN- ( )

Ig immunoglobulin (e.g., IgA, IgE, IgG, IgM)

IGF-1 insulin-like growth factor 1

IL interleukin (e.g., IL-1, IL-1 ∃ , IL-4, IL-6, IL-12)

ILL incipient lethal level

immuno immunohistochemical staining

IMP inosine monophosphate

iNOS inducible nitric oxide synthase

i.p., IP intraperitoneal

IPSC inhibitory postsynaptic currents

IQ intelligence quotient

IRT interresponse time

ISEL in situ end labeling

ISI interstimulus interval

i.v., IV intravenous

IVCD intraventricular conduction deficit

# II-xxxi JV juvenile

KABC Kaufman Assessment Battery for Children

KTEA Kaufman Test of Educational Achievement

KXRF, K-XRF K-shell X-ray fluorescence

LA lipoic acid

LB laying bird

LC lactation

LC 50 

# lethal concentration at which 50% of exposed animals die

LC 74 

# lethal concentration at which 74% of exposed animals die

LD 50 

# lethal dose at which 50% of exposed animals die

LDH lactate dehydrogenase

LDL low-density lipoprotein (cholesterol)

L-dopa 3,4-dihydroxyphenylalanine (precursor of dopamine)

LE Long Evans (rat)

LET linear energy transfer (radiation)

LH luteinizing hormone

LHRH luteinizing hormone releasing hormone

LN lead nitrate

L-NAME L- N G 

# -nitroarginine methyl ester

LOAEL lowest-observed adverse effect level

LOEC lowest-observed-effect concentration

LOWESS locally weighted scatter plot smoother

LPO lipoperoxide

LPP lipid peroxidation potential

LPS lipopolysaccharide

LT leukotriene

LT 50 

# time to kill 50%

LTER Long-Term Ecological Research (sites)

LTP long term potentiation

LVH left ventricular hypertrophy

μPIXE microfocused particle induced X-ray emission

μSXRF microfocused synchrotron-based X-ray fluorescence

MA mature

MA-10 mouse Leydig tumor cell line

MANCOVA multivariate analysis of covariance

# II-xxxii MAO monoamine oxidase

MATC maximum acceptable threshold concentration

MDA malondialdehyde

MDA-TBA malondialdehyde-thiobarbituric acid

MDCK kidney epithelial cell line

MDI Mental Development Index (score)

MDRD Modification of Diet in Renal Disease (study)

MEM Minimal Essential Medium

MG microglobulin

Mg-ATPase magnesium-dependent adenosine triphosphatase

MiADMSA monoisamyl dimercaptosuccinic acid

Mi-DMSA mi monoisoamyl dimercaptosuccinic acid

MK-801 NMDA receptor antagonist

MLR mixed lymphocyte response

MMSE Mini-Mental State Examination

MMTV murine mammary tumor virus

MN micronuclei formation

MND motor neuron disease

MNNG N -methyl- N' -nitro- N -nitrosoguanidine

MPH morphology

MRI magnetic resonance imaging

mRNA messenger ribonucleic acid

MROD methoxyresorufin- O -demethylase

MRS magnetic resonance spectroscopy

MS mass spectrometry

MSCA McCarthy Scales of Children’s Abiltities

mSQGQs mean sediment quality guideline quotients

MT metallothionein

MVV maximum voluntary ventilation

MW molecular weight (e.g., high-MW, low-MW)

N, n number of observations

N/A not available

NAAQS National Ambient Air Quality Standards

NAC N -acetyl cysteine

NAD nicotinamide adenine dinucleotide

# II-xxxiii NADH reduced nicotinamide adenine dinucleotide

NADP nicotinamide adenine dinucleotide phosphate

NAD(P)H, NADPH reduced nicotinamide adenine dinucleotide phosphate

NADS nicotinamide adenine dinucleotide synthase

NAF nafenopin

NAG N -acetyl- ∃ -D-glucosaminidase

Na-K-ATPase sodium-potassium-dep endent adenosine triphosphatase

NAWQA National Water-Quality Assessment

NBT nitro blue tetrazolium

NCBP National Contaminant Biomonitoring Program

NCD nuclear chromatin decondensation (rate)

NCS newborn calf serum

NCTB Neurobehavioral Core Test Battery

NCV nerve conduction velocity

ND non-detectable; not detected

NDI nuclear divison index

NE norepinephrine

NES Neurobehavioral Evaluation System

NF- κ B nuclear transcription factor- κ B

NGF nerve growth factor

NHANES National Health and Nutrition Examination Survey

NIOSH National Institute for Occupational Safety and Health

NIST National Institute for Standards and Technology

NK natural killer

NMDA N -methyl-D-aspartate

NMDAR N -methyl-D-aspartate receptor

NMR nuclear magnetic resonance

NO nitric oxide

NO 2 

# nitrogen dioxide

NO 3 

# nitrate

NOAEC no-observed-adverse- effect concentration

NOAEL no-observed-adverse-effect level

NOEC no-observed-effect concentration

NOEL no-observed-effect level

NOM natural organic matter

# II-xxxiv NORs nucleolar organizing regions

NOS nitric oxide synthase ; not otherwise specified

NO

x 

# nitrogen oxides

NP net productivity

NPSH nonprotein sulfhydryl

NR not reported

NRC National Research Council

NRK normal rat kidney

NS nonsignificant

NSAID non-steroidal anti-inflammatory agent

NT neurotrophin

NTA nitrilotriacetic acid

O 2 

# oxygen

ODVP offspring development

OH hydroxyl

7-OH-coumarin 7-hydroxy-coumarin

1,25-OH-D, 1,25-OH D 3 

# 1,25-dihydroxyvitamin D

24,25-OH-D 3 

# 24,25-dihydroxyvitamin D

25-OH-D 3 

# 25-hydroxyvitamin D

8-OHdG 8-hydroxy-2'-deoxyguanosine

O horizon forest floor

OR odds ratio; other oral

OSWER Office of Solid Waste and Emergency Response

P, p probability value

P300 event-related potential

P450 1A1 cytochrome P450 1A1

P450 1A2 cytochrome P450 1A2

P450 CYP3a11 cytochrome P450 3a11

PAD peripheral arterial disease

PAH polycyclic aromatic hydrocarbon

PAI-1 plasminogen activator inhibitor-1

PAR population attributable risk

Pb lead

203 

# Pb lead-203 radionuclide

204 

# Pb, 206 

# Pb, 207 

# Pb, 208 

# Pb stable isotopes of lead-204, -206, -207, -208, respectively

# II-xxxv 210 

# Pb lead-210 radionuclide

Pb(Ac) 2 

# lead acetate

PbB blood lead concentration

PbCl 2 

# lead chloride

Pb(ClO 4 

# ) 2 

# lead chlorate

PBG-S porphobilinogen synthase

PBMC peripheral bl ood mononuclear cells

Pb(NO 3 

# ) 2 

# lead nitrate

PbO lead oxides (or litharge)

PBP progressive bulbar paresis

PbS galena

PbU urinary lead

PC12 pheochromocytoma cell

PCR polymerase chain reaction

PCV packed cell volume

PDE phosphodiesterase

PDGF platelet-derived growth factor

PDI Psychomotor Development Index

PEC probable effect concentration

PEF expiratory peak flow

PG prostaglandin (e.g., PGE 2 

# , PGF 2 

# ); prostate gland

PHA phytohemagglutinin A

Pi inorganic phosphate

PIXE particle induced X-ray emission

PKC protein kinase C

pl NEpi plasma norepinephrine

PMA progressive muscular atrophy

PMN polymorphonuclear leucocyte

PMR proportionate mortality ratio

PN postnatal (day)

P5N pyrimidine 5'-nucleotidase

PND postnatal day

p.o., PO per os (oral administration)

POMS Profile of Mood States

ppb parts per billion

# II-xxxvi ppm parts per million

PPVT-R Peabody Picture Vocabulary Test-Revised

PRA plasma renin activity

PRL prolactin

PROG progeny counts or numbers

PRR prevalence rate ratio

PRWT progeny weight

PST percent transferrin saturation

PTH parathyroid hormone

PTHrP parathyroid hor mone-related protein

PVC polyvinyl chloride

PWM pokeweed mitogen

PRWT progeny weight

QA/QC quality assura nce/quality control

Q/V flux of air (Q) divided by volume of culture (V)

r Pearson correlation coefficient

R 2 

# multiple correlation coefficient

r 2 

# correlation coefficient

226 

# Ra most stable isotope of radium

R/ALAD ratio of ALAD activity be fore and after reactivation

RAVLT Rey Auditory Verbal Learning Test

86 

# Rb rubidium-86 radionuclide

RBA relative bioavailablity

RBC red blood cell; erythrocyte

RBF renal blood flow

RBP retinol binding protein

RBPH reproductive behavior

RCPM Ravens Colored Progressive Matrices

REL rat epithelial (cells)

REP reproduction

RHIS reproductive organ histology

222 

# Rn most stable isotope of radon

RNA ribonucleic acid

ROS reactive oxygen species

ROS 17.2.8 rat osteosarcoma cell line

# II-xxxvii RPMI 1640 Roswell Park Memorial In stitute basic cell culture medium

RR relative risk; rate ratio

RT reaction time

RSEM resorbed embryos

RSUC reproductive success (general)

RT reproductive tissue

∑ SEM sum of the molar concentrations of simultaneously extracted metal

SA7 simian adenovirus

SAB Science Advisory Board

SAM S -adenosyl-L-methionine

SBIS-4 Stanford-Binet Intelligence Scale-4th edition

s.c., SC subcutaneous

SCAN Test for Auditory Processing Disorders

SCE selective chemical extraction; sister chromatid exchange

SCP stripping chronopotentiometry

SD Spraque-Dawley (rat); standard deviation

SDH succinic acid dehydrogenase

SDS sodium dodecyl sulfate; Symbol Digit Substitution

SE standard error; standard estimation

SEM standard error of the mean

SES socioeconomic status

sGC soluble guanylate cyclase

SH sulfhydryl

SHBG sex hormone binding globulin

SHE Syrian hamster embryo cell line

SIMS secondary ion mass spectrometry

SIR standardized incidence ratio

SLP synthetic leaching procedure

SM sexually mature

SMAV species mean acute value

SMR standardized mortality ratio

SNAP Schneider Neonatal Assessment for Primates

SNP sodium nitroprusside

SO 2 

# sulfur dioxide

SOD superoxide dismutase

# II-xxxviii SOPR sperm-oocyte penetration rate

SPCL sperm cell counts

SPCV sperm cell viability

SQGs sediment quality guidelines

SRA Self Reported Antisocial Behavior scale

SRD Self Report of Delinquent Behavior

SRIF somatostatin

SRM Standard Reference Material

SRT simple reaction time

SSADMF Social Security Admini stration Death Master File

SSB single-strand breaks

SSEP somatosensory-evoked potential

StAR steroidogenic acute regulatory protein

STORET STOrage and RETrieval

SVC sensory conduction velocity

SVRT simple visual reaction time

T testosterone

TA tail

TABL time-averaged blood lead

T&E threatened and endangered (species)

TAT tyrosine aminotransferase

TB tibia

TBARS thiobarbituric acid-reactive species

TBPS Total Behavior Problem Score

TCDD methionine-choline-deficient diet

T cell T lymphocyte

TCLP toxic characteristic leaching procedure

TE testes

TEC threshold effect concentration

TEDG testes degeneration

TEL tetraethyl lead

TES testosterone

TEWT testes weight

TF transferrin, translocation factor

TG 6-thioguanine

# II-xxxix TGF transforming growth factor

TH tyrosine hydroxylase

232 

# Th stable isotope of thorium-232

TLC Treatment of Lead-exposed Children (study)

TNF tumor necrosis factor (e.g., TNF- α )

TOF time-of-flight

tPA plasminogen activator

TPRD total production

TRH thyroid releasing hormone

TRV toxicity reference value

TSH thyroid stimulating hormone

TSP triple-super phosphate

TT3 total triiodothyronine

TT4 serum total thyroxine

TTES total testosterone

TTR transthyretin

TU toxic unit

TWA time-weighted average

TX tromboxane (e.g., TXB 2 

# )

U uriniary

235 

# U, 238 

# U uranium-234 and -238 radionuclides

UCP urinary coproporphyrin

UDP uridine diphosphate

UNECE United Nations Economic Commission for Europe

Ur urinary

USFWS U.S. Fish and Wildlife Service

USGS United States Geological Survey

UV ultraviolet

V79 Chinese hamster lung cell line

VA Veterans Administration

VC vital capacity; vitamin C

VDR vitamin D receptor

VE vitamin E

VEP visual-evoked potential

VI variable-interval

# II-xl vit C vitamin C

vit E vitamin E

VMA vanilmandelic acid

VMI Visual-Motor Integration

VSM vascular smooth muscle (cells)

VSMC vascular smooth muscle cells

WAIS Wechsler Adult Intelligence Scale

WDS wavelength dispersive spectrometers

WHO World Health Organization

WISC Wechsler Intelligence Scale for Children

WISC-R Wechsler Intelligence Scale for Children-Revised

WO whole organism

WRAT-R Wide Range Achievement Test-Revised

WT wild type

WTHBF-6 human liver cell line

ww wet weight

XAFS X-ray absorption fine structure

XANES X-ray absorption near edge spectroscopy

XAS X-ray absorption spectroscopy

XPS X-ray photoelectron spectroscopy

X-rays synchrotron radiation

XRD X-ray diffraction

XRF X-ray fluorescence

ZAF correction in reference to thr ee components of matrix effects:
atomic number (Z), absorpti on (A), and fluorescence (F)

ZnNa 2 

# DTPA zinc disodium diet hylenetriaminepentaacetic acid

ZnNa 2 

# EDTA zinc disodium ethyl enediaminetetraacetic acid

ZPP zinc protoporphyrin

# AX6-1 

# AX6. CHAPTER 6 ANNEX

# AX6-2 

# ANNEX TABLES AX6-2

# AX6-3Table AX6-2.1. Prospective Longitudinal CohortStudies of Neurocognitive Ability in ChildrenReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited StatesBellinger et al. (1992)U.S.148 subjects from the Boston Prospective Studywere re-evaluated at 10 yrs of age. The WISCRwas used to index intellectual status. Extensiveassessment of medicaland sociodemographiccovariates.Cord and serial postnatalblood Pb assessmentsCord blood Pb grouping <3,6-7, >10 μg/dLBlood Pb at 2 yrs 6.5(SD 4.9) μg/dLIncrease of 10 μg/dL in blood Pb level at age two wasassociated with a decrement of ~6 IQ points. Relationshipwas stronger for verbal compared to performance IQ.Prenatal exposure to Pb as indexed by cord blood Pb levelswas unrelated to psychometric intelligence.Dietrich et al.(1991, 1992, 1993a);Ris et al. (2004)U.S.253-260 children followed since birth in theCincinnati Pb Study were re-evaluated at 4, 5, and6.5 yrs of age. At 4 and 5 yrs, the KABC was usedto index intellectual status. At 6.5 yrs, the WISCRwas administered. At 15-17 yrs of age, 195Cincinnati Pb Study subjects were re-evaluated byuse of a comprehensive neuropsychological batterythat yielded a “Learning/IQ” factor in a principalcomponents analysis. Extensive assessment ofmedical and sociodemographic covariates.Prenatal (maternal) and serialpostnatal blood PbassessmentsPrenatal blood Pb 8.3(SD 3.7) μg/dLBlood Pb at 2 yrs 17.4(SD 8.8) μg/dLFew statistically significant relationships between blood Pbindices and covariate-adjusted KABC scales at 4 and 5 yrsof age. One KABC subscale that assesses visual-spatialskills was associated with late postnatal blood Pb levelsfollowing covariate adjustment. After covariateadjustment, avg postnatal blood Pb level was significantlyassociated with WISCR performance IQ at 6.5 yrs. BloodPb concentrations >20 μg/dL were associated with deficitsin performance IQ on the order of 7 points compared withchildren with mean blood Pb concentrations <10 μg/dL.At 15-17 yrs, late childhood blood Pb levels weresignificantly associated with lower covariate-adjustedLearning/IQ factor scores.Canfield et al. (2003a)U.S.172 predominantly African-American, lowersocioeconomic status children in Rochester, NYfollowed since they were 5 to 7 mos were evaluatedat 3 and 5 yrs. An abbreviated form of theStanford-Binet Intelligence Scale-4 (SBIS-4) wasused to index intellectual status. Extensiveassessment of medicaland sociodemographiccovariates.Serial postnatal blood PbBlood Pb at 2 yrs9.7 μg/dLFollowing covariate adjustment, there was a significantinverse relationship between blood Pb indices and IQ at allages. Overall estimate indicated that an increase in avglifetime blood Pb concentration of 1 μg/dL was associatedwith a loss of 1⁄2 IQ point. Effects were stronger forsubjects whose blood Pb levels never exceeded 10 μg/dL.Semiparametric analysis indicated a decline in IQ of 7.4points for a lifetime avg blood Pb concentration up to10 μg/dL, while for levels between 10 and 30 μg/dL amore gradual decrease in IQ was estimated. Authorsconcluded that the most important aspect of their findingswas that effects below 10 μg/dL observed in previouscross-sectional studies havenow been confirmed by thisrigorous prospective study.

# AX6-4Table AX6-2.1 (cont’d). Prospective Longitudinal Cohort Studies of Neurocognitive Ability in ChildrenReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited States(cont’d)Bellinger andNeedleman (2003)U.S.Reanalysis of data from the Boston ProspectiveStudy focusing on 48 subjects at 10 yrs of agewhose blood Pb levels never exceeded 10 μg/dL.WISCR was used to index intellectual status. Seealso Bellinger et al. (1992)Serial postnatal blood PbBlood Pb at 2 yrs 6.5(SD 4.9) μg/dLIQ was inversely related to two-yr blood Pb levelsfollowing covariate adjustment. Blood Pb coefficient(!1.56) was greater than that derived from analysesincluding children with concentrations above 10 μg/dL(!0.58). Authors conclude that children’s IQ scores arereduced at Pb levels still prevalent in U.S.Chen et al. (2005)U.S.Repeat measure psychometric data on 780 childrenenrolled in Treatment of Pb-Exposed Children(TLC) clinical trial were analyzed to determine ifblood Pb concentrations at2 yrs of age constitute acritical period of exposure for expression of laterneurodevelopmental deficits. Data for placebo andactive drug groups were combined in theseanalyses, which spanned ~2 to 7 yrs of age.Measures of intellectual status included the BayleyMental Development Index (MDI) and full scale IQderived from age-appropriate Wechsler scales.Blood PbRange 20-44 μg/dLBaseline blood Pb 26(SD 26.5) μg/dL in both drugand placebo groupsBlood Pb at 7 yrs 8.0(SD 4.0) μg/dLAssociation between blood Pb and psychometricintelligence increased in strength as children became older,whereas the relation between baseline (2 yr) blood Pb andIQ attenuated. Peak blood Pb concentration thus does notfully account for the observed association in older childrenbetween their lower blood Pb concentrations and IQ. Theeffect of concurrent blood Pb on IQ may thusly be greaterthan currently believed. Authors conclude that these data(a) support the idea that Pb exposure continues to be toxicto children as they reach school age and (b) do not lendsupport to the interpretation that majority of the damage isdone by the time the child reaches 2 to 3 yrs of age.

# AX6-5Table AX6-2.1 (cont’d). Prospective Longitudinal Cohort Studies of Neurocognitive Ability in ChildrenReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationEuropeWasserman et al. (1992,1994, 2003); Factor-Litvak et al. (1999)YugoslaviaBirth cohort of ~300-400 infants followed sincebirth residing in two towns in Kosovo, Yugoslavia,one group near a longstanding Pb smelter andbattery manufacturing facility and another in arelatively unexposed location 25 miles away.Intellectual status was monitored from 2 to10-12 yrs of age with the Bayley Scales of InfantDevelopment, McCarthy Scales of Children’sAbilities, and WISCIII. Extensive assessment ofmedical and sociodemographic covariates.Maternal prenatal, umbilicalcord, and serial postnatalblood PbMaternal blood Pb in exposedarea 19.9 (SD 7.7) μg/dL,unexposed area 5.6 (SD 2.0)μg/dLUmbilical cord blood Pb inexposed area 22.2 (SD 8.1)μg/dL, unexposed area 5.5(SD 3.3) μg/dLBlood Pb at 2 yrs inexposed area 35.4 μg/dL,unexposed area 8.5 μg/dLPostnatal blood Pb increment from 10 to 30 μg/dL at 2 yrsof age associated with covariate-adjusted decline of 2.5points in Bayley MDI. Maternal and cord blood Pb notconsistently associated withBayley outcomes. Higherprenatal and cord blood Pb concentrations associated withlower McCarthy General Cognitive Index (GCI) scores at4 yrs. Scores on the Perceptual-Performance subscaleparticularly affected. After covariate-adjustment, childrenof mothers with prenatal blood Pb levels >20 μg/dL scoreda full standard deviation below children in the lowestexposure group (<5 μg/dL prenatal blood Pb). Postnatalblood Pb also associated with poorer performance.Increase in blood Pb level from 10 to 25 μg/dL associatedwith a reduction of 3.8 points in GCI after covariateadjustment. Effects even more pronounced on thePerceptual-Performance subscale. At 7 yrs, significantinverse associations betweenlifetime avg blood Pb andWISCIII IQ were observed, including consistently strongerassociations with Performance IQ and later blood Pbmeasures. Adjusted intellectual loss associated with anincrease in lifetime avg blood Pb from 10 to 30 μg/dL wasover 4 points in WISCIII Full-Scale and Performance IQ.At 10-12 yrs, subjects wereagain assessed with theWISCIII. Following covariate-adjustment, avg lifetimeblood Pb was associated with all components of theWISCIII, with effect sizes similar to those observed at7 yrs. In most instances, bone Pb-IQ relationships werestronger than those for blood Pb among subjects residingnear the Pb smelter.

# AX6-6Table AX6-2.1 (cont’d). Prospective Longitudinal Cohort Studies of Neurocognitive Ability in ChildrenReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationLatin AmericaSchnaas et al. (2000)Mexico112 children followed since birth with completepsychometric data from the Mexico CityProspective Study were examined. Intellectualstatus indexed by General Cognitive Index (GCI)from McCarthy Scales of Children’s Abilities(MSCA). Purpose of the study was to determine ifmagnitude of the effect ofpostnatal blood Pb levelson cognition varies with time between blood Pband cognitive assessments.Serial postnatal blood PbAvg blood Pb24-36 mos 9.7(range 3-48) μg/dLA number of significant interactions observed betweenblood Pb levels and age of assessment. Greatest effectobserved at 48 mos, when a 5.8 deficit in adjusted GCIscores was observed for each natural log increment inblood Pb. Authors concluded that four to five yrs of ageappears to be a critical period for manifestation of earlierpostnatal blood Pb level effects on cognition.Schnaas et al. (2006)MexicoFrom the Mexico City Prospective Study, 150children followed since birth with complete datafor all covariates were examined. Intelligence fromage 6 to 10 yrs was assessed using the WISC-R.Blood Pb measurements from various time points,starting from maternal blood Pb levels during the2nd trimester to postnatal Pblevels at age 10 yrs.Serial prenatal (maternal) andpostnatal blood PbGeometric mean blood PbDuring pregnancy 8.0(range 1-33) μg/dLAge 1-5 yrs 9.8(range 2.8-36.4) μg/dLAge 6-10 yrs 6.2(range 2.2-18.6) μg/dLAmong all the Pb variables atthe various time points, onlylog-transformed blood Pb levels during the 3rd trimesterwere significantly associated with full scale IQ at ages 6 to10 yrs, after adjusting forpotential confounders. A 3.44point deficit in full scale IQwas observed for each naturallog increment in blood Pb.The authors note that, given the modest sample size andrelatively low power of this study, they do not claim thatPb exposure from other developmental period has no effecton child IQ.Gomaa et al. (2002)Mexico197 two yr-old children residing in Mexico Cityfollowed since birth. Bayley Scales of InfantDevelopment Mental Development Index (MDI)used to index intellectual status. Extensiveassessment of medicaland sociodemographiccovariates.Umbilical cord and serialpostnatal blood PbUmbilical cord bloodPb 6.7 (SD 3.4) μg/dLBlood Pb at 2 yrs 8.4(SD 4.6) μg/dLMaternal tibial and patellarbone PbPatellar (trabecular)bone Pb 17.9 (SD 15.2) μg/gUmbilical cord blood Pb and patellar (trabecular) bone Pbsignificantly associated withlower Bayley MDI scores.Maternal trabecular bone Pb levels predicted poorersensorimotor functioning at two yrs independent ofconcentration Pb measured in cord blood. Increase in cordblood Pb level from 5 to 10 μg/dL was associated with a3.1 point decrement in adjusted MDI scores. In relation tolowest quartile of trabecular bone Pb, the 2nd, 3rd, and 4thquartiles were associated with 5.4, 7.2, and 6.5 decrementin MDI following covariate adjustment. Authorsconcluded that higher maternal trabecular bone Pb levelsconstitute an independent risk factor for impaired mentaldevelopment in infancy, likelydue to the mobilization ofmaternal bone Pb stores over gestation.

# AX6-7Table AX6-2.1 (cont’d). Prospective Longitudinal Cohort Studies of Neurocognitive Ability in ChildrenReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationLatin America (cont’d)Téllez-Rojo et al.(2006)Mexico294 one and two yr-olds residing in Mexico Cityfollowed since birth. The Bayley Scales of InfantDevelopment-II (MDI and PDI) were used to indexdevelopmental status. There was extensiveassessment of medicaland sociodemographiccovariates.Umbilical cord blood Pb andpostnatal blood Pb at 12 and24 mosUmbilical cord blood Pb 4.8(SD 3.0) μg/dLBlood Pb at 1 yr 4.27 (SD2.1) μg/dLBlood Pb at 2 yrs 4.3 (SD2.2) μg/dLBlood Pb at 12 mos was not associated with MDI at eitherage. Blood Pb at 24 mos was significantly associated with24 mo MDI. An increase of one logarithmic unit in 24 moblood Pb level was associatedwith a reduction of ~5 pointsin MDI. Findings for PDI were similar. In comparison toa supplemental subsample of 90subjects with blood Pblevels >10 μg/dL, the coefficient for blood Pb wassignificantly larger for infants never exceeding that levelof internal dose. A steeper inverse slope was observedover the blood Pb range up to 5 μg/dL (!1.71 points per1 μg/dL increase in blood Pb, p = 0.01) compared to therange between 5 and 10 μg/dL (!0.94 points, p = 0.12);however, these slopes were not significantly different(p = 0.34). In conclusion, a major finding of thisprospective study was that a significant inverserelationship between blood Pb concentration andneurodevelopment was observed among children whoseblood Pb levels did not exceed 10 μg/dL at any age.AustraliaBaghurst et al. (1992);McMichael et al.(1994); Tong et al.(1996)Australia400-500 subjects residing inand near Port Pirie,Australia and followed since birth were re-evaluatedat 7 to 8 and 11-13 yrs of age. WISCR was used toindex intellectual statusat both ages. Extensiveassessment of medicaland sociodemographiccovariates.Maternal prenatal, umbilicalcord and serial postnatal bloodPbAntenatal avg blood Pb10.1 (SD 3.9) μg/dLUmbilical cord blood Pb9.4 (SD 3.9) μg/dLBlood Pb at 2 yrsgeometric mean 21.3(SD 1.2) μg/dLDeciduous central incisorwhole tooth PbTooth Pb geometric 8.8(SD 1.9) μg/gSignificant decrements in covariate-adjusted full scale IQwere observed in relationship topostnatal blood Pb levelsat both ages. At 7 to 8 yrs of age a loss of 5.3 points wasassociated with an increase in blood Pb from 10 to30 μg/dL. At 11-13 yrs, mean full scale IQ declined by 3.0points for an increase in lifetime avg blood Pbconcentrations from 10 to 20 μg/dL. Pb levels in centralupper incisors were also associated with lower 7-8 yr IQfollowing covariate adjustment. Adjusted estimateddecline in IQ across the range of tooth Pb from 3 to22 ppm was 5.1 points.

# AX6-8Table AX6-2.1 (cont’d). Prospective Longitudinal Cohort Studies of Neurocognitive Ability in ChildrenReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationAustralia(cont’d)Cooney et al. (1991)Australia175 subjects from the Sydney,Australia ProspectiveStudy were assessed at 7 yrs of age. The WISCRwas used to index intellectual status. Extensiveassessment of medicaland sociodemographiccharacteristics.Maternal and cord blood PbCord blood Pb 8.4 μg/dL(SD not given)Blood Pb at 2 yr 15.8 μg/dL(SD not given)Blood indices of Pb exposure were not associated with anymeasure of psychometric intelligence. Authors concludethat the evidence from their study indicates that ifdevelopmental deficits do occur at blood Pb levels<25 μg/dL, the effect size is likely to be small (<5%).Sydney results are difficult to interpret from the statisticalpresentation in their report. Itis not clear which covariateswere entered into regression analyses nor is the empiricalor substantive basis for their conclusion.AsiaShen et al. (1998)ChinaPregnant women and newborns in Shanghai, Chinarecruited from health care facilities in the communityon the basis of cord blood Pb concentrationpercentiles (30th and 70th) yielding a total N of 173subjects. The Bayley Scales of Infant DevelopmentMental Development Index (MDI) and PsychomotorDevelopment Index (PDI) were used to indexsensorimotor/intellectual statusat 3, 6, and 12 mos.Extensive assessment of medical andsociodemographic characteristics.Cord blood Pb“High group” 13.4 (SD 2.0)μg/dL“Low group” 5.3 (SD 1.4)μg/dLBlood Pb at 1 yr“High group” 14.9 (SD 8.7)μg/dL“Low group” 14.4 (SD 7.7)μg/dLAt all ages the Bayley MDI was associated with cordblood Pb groupings following adjustment for covariates.Postnatal blood Pb unrelated to any Bayley measures.Differences in MDI betweenprenatal blood Pb exposuregroupings generally in accordwith similar investigationsin Boston, Cincinnati, and Cleveland. Authors concludethat the adverse effects of prenatal Pb exposure are readilydiscernible and stable over the first yr of life.

# AX6-9Table AX6-2.2. Meta- and Pooled-Analysesof Neurocognitive Ability in ChildrenReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationLanphear et al. (2005) Pooled analysisof seven international prospectivestudies involving 1,333 school-age children.Primary outcome measure was full-scale IQ asassessed by age-appropriate Wechsler scale.Measures of exposure were concurrent, peak, avglifetime and “early” blood Pb(i.e. mean blood Pbfrom 6-24 mos). Cord blood Pb was alsoinvestigated for those studies that collected thesesamples at birth. Multivariate regression modelswere developed adjusting for site as well as 10common covariates. BloodPb measure with thelargest adjusted R2was nominated a priori as thepreferred index for relating Pb exposure to IQ insubsequent analyses. Results evaluated by applyinga random-effects model.Umbilical cord blood PbSerial postnatal blood PbLifetime avg blood Pb 12.4(range 4.1-34.8) μg/dLConcurrent blood Pb level exhibited the strongestrelationship with IQ, although results of regression analysesfor all blood Pb variables were similar. Steepest declines inIQ were at blood Pb concentrations below 10 μg/dL. Forthe entire pooled data set, a decline of 6.2 IQ points (95%CI: 3.8, 8.6) was estimatedfor an increment in blood Pbfrom 1 to 10 μg/dL.Needleman andGatsonis (1990)Meta analysis of 12 studies chosen on the basis ofquality—covariate assessment and application ofmultiple regression techniques. Studies weighted onbasis of sample size. Studies divided according totissue analyzed (blood or teeth). Joint p-values andavg effect sizes calculated using two differentmethods.Blood PbTooth PbJoint p-values for blood Pb studies were <0.0001 for bothmethods, whereas joint p-values of <0.0006 and <0.004were obtained for teeth. Partial correlations ranged from–0.27 to –0.0003. No single study was responsible for thesignificance of the final findings. Authors concluded thatthe hypothesis that Pb lowers children’s IQ at relatively lowdose is strongly supported by results of this quantitativereview.Schwartz (1994) Meta analysis of7 recent studies relating blood Pb toIQ were reviewed, three longitudinal and four crosssectional. Measure of effect was estimated decreasein IQ for an increase in blood Pb from 10 to 20μg/dL. Studies were weighted by the inverse of thevariances using randomBlood PbEstimated decrease in IQper blood Pb increment from 10 to20 μg/dL was –2.6 points (SE 0.41). Results were notdetermined by any individual study. Effect estimates weresimilar for longitudinal and cross-sectional studies.For studies with mean blood Pblevels <15 μg/dL, estimatedeffect sizes were larger. When the study with the lowestexposures was examined alone using nonparametricsmoothing (Boston), no evidence of a threshold wasobserved down to a blood Pb level of 1 μg/dL. Authorconcludes that these data provide further evidence of Pbeffects on cognition at levels below 10 μg/dL.

# AX6-10Table AX6-2.2 (cont’d). Meta- and Pooled-Analyses of Neurocognitive Ability in ChildrenReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationPocock et al. (1994) Meta-analysis offive prospective and fourteen cross-sectional studies (including tooth and blood tissues)were included. The fixed effect method ofThompson and Pocock (1992) was employed.Only blood Pb at or near two yrs of age wasconsidered for the prospective studies.Blood PbTooth PbOverall conclusion was that a doubling of blood Pb levelsfrom 10 to 20 μg/dL, or tooth Pb from 5 to 10 μg/g wasassociated with an avg estimated deficit in IQ of ~1-2points. Authors caution interpretation of these results andPb literature in general, citing questions aboutrepresentativeness of the samples, residual confounding,selection bias, and reverse causality.

# AX6-11Table AX6-2.3. Cross-Sectional Studiesof Neurocognitive Ability in ChildrenReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationUnited StatesLanphear et al. (2000)U.S.4,853 U.S. children ages six to 16 yrs enrolled inNHANES-III. Two subtests of the WISC-R (BlockDesign and Digit Span) used to assess intellectualstatus. Medical and sociodemographic covariates wereassessedBlood Pb at time of testingGeometric blood Pb 1.9(SE 0.1) μg/dL2.1% with blood Pb∃10 μg/dLMultivariate analyses revealed a significant associationbetween blood Pb levels and both WISC-R subtests.Associations remained statistically significant whenanalyses were restricted to children with blood Pb levelsbelow 10 μg/dL. Authors caution that lack of control forparental intelligence and variables like the HOME scaleshould temper any conclusions regarding observed effects.Emory et al. (2003)U.S.77 healthy, lower-risk African-American infants age 7mos. The Fagan Test of Infant Intelligence (FTII) wasadministered to assess intellectual status. Birth weightand gestational age examined as potentialcovariates/confounders.Maternal blood PbBlood Pb 0.72 (SD 0.86)μg/dLInfants scoring in the upper 5th to 15th percentiles for theFTII had mother with significantly lower maternal bloodPb levels when compared to those scoring in the lower5th or 15th percentile. Findings of this study should beconsidered preliminary due tosmall sample size and lackof covariate assessment or control.Chiodo et al. (2004)U.S.237 African-American inner-city children assessed at7.5 yrs of age. Cohort was derived from a larger studyof the effects of prenatal alcohol exposure on childdevelopment. 83% of children in Pb study had little orno gestational exposure to alcohol. WISC-III wasadministered to assess intellectual status. Medical andsociodemographic covariates were assessed.Blood Pb at time of testingBlood Pb 5.4 (SD 3.3)μg/dLFollowing covariate adjustment statistically significantrelationships between blood Pband full-scale, verbal andperformance IQ were observed.Significant effects of Pbon full-scale and performance IQ was evident at blood Pbconcentrations below 7.5 μg/dL.EuropeWalkowiak et al.(1998)Germany384 six-yr-old children in three German cities. Twosubtests of the WISC (Vocabulary and Block Design)used to estimate IQ. Both subscales were combined toform a “WISC Index.” Medical and sociodemographiccovariate covariates were assessed.Blood Pb at time of testingBlood Pb 4.2 μg/dL95th percentile 8.9 μg/dLFollowing covariate-adjustment, WISC Vocabulary wassignificantly associated withblood Pb but combined WISCindex was borderline. Authors conclude that findingsroughly correspond with those of other studies that findeffects below 10 μg/dL but caution that potentiallyimportant covariates such as HOME scores were notcontrolled.Prpic-Majic et al.(2000)Croatia275 3rd and 4th grade students in Zagreb, Croatia.WISC-R was administered to assess intellectual status.Covariate factors limited to parents’ educational statusand gender of child.Blood Pb at time of testingBlood Pb 7.1 (SD 1.8)μg/dLFollowing covariate adjustment,no statistically significantassociations were observed for Pb or other indicators oftoxicity (ALAD, EP) on WISC-R. Authors argue thatstudy had sufficient power and that the “no-effect”threshold for Pb must be in the upper part or above thestudy’s range of exposures.

# AX6-12Table AX6-2.3 (cont’d). Cross-Sectional Studies of Neurocognitive Ability in ChildrenReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationLatin AmericaKordas et al. (2004,2006)Mexico602 1st grade children in public schools in a highlyindustrialized area of northern Mexico. Premise ofstudy was that effects of Pb could be explained bycorrelated nutritional factors such as iron status,anemia, and growth. Peabody Picture VocabularyTest-Revised (PPVT-R),Cognitive Abilities Test(CAT), and an abbreviated form of the WISC-R wereadministered to assess intellectual status. Medical andsociodemographic covariates were assessed.Blood Pb at time of testingBlood Pb 11.5(SD 6.1) μg/dLFollowing covariate adjustment blood Pb levels weresignificantly associated with poorer performance on thePPVT-R, WISC-R Coding, and Number and LetterSequencing, a Math Achievement Test, and the SternbergMemory Test. Authors concluded that Pb’s associationwith iron deficiency anemiaor growth retardation couldnot explain relationship between Pb and cognitiveperformance. Non-linear analyses of selectedneurocognitive outcomes revealed that dose-responsecurves were steeper at lower than at higher blood Pblevels. Moreover, the slopesappeared negative at bloodPb levels below 10 μg/dL, above which they tend toplateau. Effects of Pb on neurocognitive attainmentappeared to be greatestamong the least advantagedmembers of the cohort.Counter et al. (1998)Ecuador77 chronically Pb-exposed children living inEcuadorian villages where Pb is used extensively incommercial ceramics production. Ravens ColoredProgressive Matrices (RCPM) used to indexintellectual status. Only half of the sample wasassessed. No assessment of medical orsociodemographic covariates.Blood Pb at time of testingBlood Pb 47.4 (SD 22)μg/dLSimple regression analysis revealed a correlation betweenblood Pb and RCPM of only borderline significance.Results difficult to interpret because there was no attemptto age-adjust. When analysis restricted to children 9 to11 yrs of age, a highly significant negative correlation wasobtained. Study has little relevance to the question of Pbhazards in the U.S. because of unusually high levels ofexposure.AsiaRabinowitz et al.(1991)Taiwan443 children in grades one to three in Taipei City andthree schools near Pb smelters. Ravens ColoredProgressive Matrices (RCPM) used to indexintellectual status. Medical and sociodemographiccovariate factorswere assessed.Dentin tooth PbTaipei City 4.3 (SD 3.7)μg/gSmelter areas 6.3 (SD 3.3)μg/gScores on the RCPM were negatively correlated with toothPb concentrations. In multivariate analyses, parentaleducation was the most important predictor of RCPMscores, but tooth Pb concentrations still significantlypredicted lower scores in females residing in low-incomefamilies.Bellinger et al. (2005)India74 four to fourteen yr-old children residing in Chennai,India were enrolled in the study, 31 of which wereassessed with the Binet-Kamath Intelligence test. Datawere collected on sociodemographic features ofsubjects’ families.Blood Pb at time of testingBlood Pb 11.1 (SD 5.6)μg/dLCovariate-adjusted blood Pbcoefficient was negative butnonsignificant, perhaps due tosmall sample size andhighly variable performance of subjects with the leastelevated blood Pb concentrations.

# AX6-13Table AX6-2.3 (cont’d). Cross-Sectional Studies of Neurocognitive Ability in ChildrenReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationMiddle EastAl-Saleh et al. (2001)Saudi Arabia533 Riyadh, Saudi Arabian girls (6-12 yrs of age) wereadministered a variety of standardized tests includingthe TONI, and the Beery VMI. Extensive data werecollected on potentially confounding variablesincluding sociodemographic variables, earlydevelopmental milestones and child health status.Blood Pb at time of testingBlood Pb 8.1 (SD 3.5)μg/dLBlood Pb levels had no impact onTONI scores but this testhas limited evidence of validity in this population.Significant negative associations were noted betweenblood Pb levels and the Beery VMI suggesting anassociation between impairment in visual-spatial skills inSaudi children with blood Pb levels in the range of 2.3 to27.4 μg/dL.

# AX6-14Table AX6-2.4. Effects of Lead onAcademic Achievement in ChildrenReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationUnited StatesLanphear et al. (2000)U.S.Design: Cross-sectional.4,853 U.S. children agessix to 16 yrs enrolled in NHANES-III. Subjectswere administered the Arithmetic and Readingsubtests of the WideRange Achievement Test-Revised (WRATR). Anumber of medical andsociodemographic covariates were assessed andentered into multivariable models.Blood Pb at time of testingGeometric blood Pb 1.9(SE 0.1) μg/dL2.1% with blood Pb∃10 μg/dLFollowing covariate adjustment, a statistically significantrelationship between blood Pb and WRATR performancewas found. A 0.70 point decrement in Arithmetic scoresand a 1 point decrement in Reading scores for each1 μg/dL increase in blood Pb concentration was observed.Statistically significant inverse relationships between bloodPb levels and performance for both Reading andArithmetic subtests were found for children with blood Pbconcentrations <5 μg/dL. Authors concluded that resultsof these analyses suggest thatdeficits in academic skillsare associated with blood Pb concentrations lower than5 μg/dL. They cautioned,however, that two covariatesthat have been shown to be important in other Pb studies(i.e., parental IQ and HOME scores) were notavailable.This may have over or under estimated deficits inacademic skills related to Pb. They further caution that, aswith all cross-sectional studies utilizing blood Pb as theindex of dose it is not clearwhether deficits in academicskills were due to Pb exposure that occurred sometimeduring early childhood or due to concurrent exposure.Nevertheless, concurrent bloodPb levels reflect bothongoing exposure and preexisting body burden.Needleman et al. (1990)U.S.Design: Prospective cohort.Re-examination of theChelsea and Somerville cohort recruited in the1970’s (Needleman et al.,1979). 132 adolescentswere recalled. Large battery of tests wasadministered to examine neurobehavioral deficitsand academic achievement in high school and shortlyfollowing graduation. Extensive assessment ofmedical and sociodemographic covariates.Tooth (dentin) PbTooth Pb median 8.2 μg/gSubjects with dentin Pb levels>20 ppm were at higher riskof dropping out of high school (adjusted OR = 5.8 [95%CI: 1.4, 40.7]) and of having a reading disability (adjustedOR = 5.8 [95% CI: 1.7, 19.7]). Higher dentin Pb levelswere also significantly associated with lower classstanding, increased absenteeism, and lower vocabulary andgrammatical reasoning scores on the NeurobehavioralEvaluation System (NES). Authors conclude that undueexposure to Pb has enduring and important effects onobjective parameters of success in life.

# AX6-15Table AX6-2.4 (cont’d). Effects of Leadon Academic Achievement in ChildrenReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationUnited States(cont’d)Bellinger et al. (1992)U.S.Design: Prospective longitudinal. 148 children inthe Boston Pb Study cohort were examined at 10 yrsof age. The short-form of the Kaufman Test ofEducational Achievement (KTEA) was used to assessacademic achievement. Primary outcome was theBattery Composite Score. Extensive assessment ofmedical and sociodemographic covariates.Cord and serial postnatalblood Pb assessments.Cord blood Pb grouping <3,6-7, >10 μg/dLBlood Pb at 2 yrs 6.5(SD 4.9) μg/dLAfter covariate-adjustment, blood Pb levels at 24 mos weresignificantly predictive of lower academic achievement(∃=!0.51, SE 0.20). Battery Composite Scores declined by8.9 points for each 10 μg/dL increase in blood Pb. Thisassociation was significant after adjustment for IQ. Authorsconclude that Pb-sensitive neuropsychological processing andlearning factors not reflected in measures of global intelligencemay contribute to deficits in academic achievement.Leviton et al. (1993)U.S.Design: Prospective cohort.Teachers of ~2000 eightyr-old children born in 1 hospital in Boston between1979 and 1980 filled out the Boston TeachersQuestionnaire (BTQ) to assess academicperformance and behavior. Limited information isprovided on the assessment of covariate factors but anumber were considered and controlled for inmultivariable analyses.Cord blood PbCord blood Pb 6.8 μg/dLTooth (dentin) PbTooth Pb 2.8 μg/gFollowing adjustment for potential confounding variables,elevated dentin Pb concentrations were associated withstatistically significant reading and spelling difficulties asassessed by the BTQ among girls in the sample. Authorsconclude that their findings support the case for Pb-associatedlearning problems at levels that were prevalent at that time inthe general population. However, authors add that the inabilityto assess child-rearing quality inthis study conducted by maillimits the inferences that can be drawn.AustraliaFergusson et al. (1993,1997); Fergusson andHorwood (1993)New ZealandDesign: Prospective cohort.Academic performancewas examined in a birth cohort of 1200 New Zealandchildren enrolled in the Christchurch Health andDevelopment Study. Measures of academicperformance at 12-13 yrsincluded the Brut ReadingTest, Progressive Achievement Test, Test ofScholastic Abilities, and teacher ratings of classroomperformance in the areas of reading, writing, andmathematics. The growth of word recognition skillsfrom 8 to 12 yrs was also examined using growthcurve modeling methods. Academic achievement inrelationship to Pb was re-examined in this cohort at18 yrs. Measures of academic achievement includedthe Burt Reading Test, number of yrs of secondaryeducation, number of certificates passed (based onnational examinations), and leaving school withoutformal qualifications(failing to graduate). Extensiveassessment of medical and social covariates.Tooth (dentin) PbTooth Pb 6.2 (SD 6.2) μg/gFollowing covariate adjustment, dentin Pb levels weresignificantly associated with virtually every formal index ofacademic skills and teacher ratings of classroom performancein 12-13 yr-olds. After adjustment for covariates, tooth Pblevels greater than 8 μg/g were associated with significantlyslow growth in word recognitionabilities with no evidence ofcatch up. At 18 yrs, tooth Pb levels were significantlyassociated with lower reading test scores, having a readinglevel of less than 12 yrs, failing to complete three yrs of highschool, leaving school withoutqualifications, and meannumber of School Certificates passed. Authors conclude thatearly exposure to Pb is independently associated withdetectable and enduring deficits in children’s academicabilities. They further conclude that their findings areparticularly significant in that they confirm the findings ofNeedleman (1990), albeit in a cohort with lower levels ofexposure to environmental Pb.

# AX6-16Table AX6-2.4 (cont’d). Effects of Leadon Academic Achievement in ChildrenReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationAsiaWang et al. (2002a)TaiwanDesign: Cross-sectional. 934 3rd graders living inan urban industrial area of Taiwan. Outcomevariables were grades for Chinese (reading, writing),mathematics, history, and natural science. Gradeswere converted into individual class rankings toavoid teacher bias. Limited data on medical andsociodemographic covariates.Blood Pb at time ofevaluationBlood Pb 5.5 (SD 1.9)μg/dLFollowing covariate adjustment, blood Pb was significantlyassociated with lower class ranking in all academicsubjects. Major shortcomingof this study is lack ofcontrol for potentially important covariates such asparental IQ. However, the relatively low levels ofexposure in this sample and strength and consistency of thereported relationships suggest that Pb may be playing somerole in lowering academic performance.Rabinowitz et al. (1992)TaiwanDesign: Cross-sectional. Teachers of 493 childrenin grades 1-3 filled out the Boston TeachersQuestionnaire (BTQ) to assess academicperformance and behavior. Sociodemographic andmedical covariate factors were assessed.Tooth (dentin) PbTooth Pb 4.6 (SD 3.5) μg/gPrior to adjustment for covariates, girls with higherexposures to Pb evinced a borderline significant trend forreading difficulties while byes displayed significantlyincreased difficulties with respect to activity levels andtask attentiveness. In logistic regression models thatinclude significant covariatefactors, the tooth Pb termsfailed to achieve statistical significance. Authors concludethat Pb levels found in the teeth of children in thisTaiwanese sample are not associated with learningproblems as assessed by the BTQ.Middle EastAl Saleh et al. (2001)Saudi ArabiaClass rank, as assessed by the teacher, was examinedin conjunction with blood Pb levels in 533 Riyadh,Saudi Arabian girls (6-12 yrs of age). Extensive datawere collected on potentially confounding variablesincluding sociodemographic variables, earlydevelopmental milestones and child health status.Blood Pb at time of testingBlood Pb 8.1 (SD 3.5)μg/dLA significant inverse relationship between blood Pb levelsand rank percentile scores was observed after adjusting fora number of demographic and socioeconomic variables.When multiple regression models were fitted to a subset ofstudents with blood Pb levels below 10 μg/dL, class rankpercentile continued to show a statistically significantassociation with blood Pb levels.

# AX6-17Table AX6-2.5. Effects of Lead on Specific Cognitive Abilitiesin Children — Attention/Executive Functions, Learning, andVisual-spatial SkillsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited StatesBellinger et al. (1994a)U.S.Design: Prospective cohort. 79 subjects from theoriginal Chelsea and Somerville, MA Pb study werere-evaluated at 19-20 yrs of age with the Mirskybattery of attentional measures. Extensive measuresof medical and sociodemographic covariates.Tooth (dentin) PbTooth Pb 13.7 (SD 11.2)μg/gKXRF Bone PbTibial bone Pb(range <1 - >10) μg/gPatellar bone Pb(range <1 - >15) μg/gHigher tooth Pb concentrations were significantlyassociated with poorer scores on the Focus-Execute andShift factors of the Mirsky battery. Few significantassociations were observedbetween bone Pb levels andperformance. Authors conclude that early Pb exposuremay be associated with poorer performance onexecutive/regulatory functions, which are thought todepend on the frontal or prefrontal regions of the brain.Stiles and Bellinger(1993)U.S.Design: Prospective longitudinal. 148 subjects fromthe Boston Pb Study were re-evaluated at 10 yrs ofage with an extensive neuropsychological battery.Tests included the California Verbal Learning Test,Wisconsin Card Sorting Test, Test of Visual-MotorIntegration, Rey-Osterieth Complex Figure, StoryRecall, Finger Tapping, and Grooved Pegboard.Extensive measures of medical andsociodemographic covariates.Cord and serial postnatalblood Pb assessmentsCord blood Pb grouping <3,6-7, >10 μg/dLBlood Pb at 2 yrs 6.5(SD 4.9) μg/dLAuthors point out that the number of significantassociations was about equal to those that would beexpected by chance. However, tasks that assess attentionalbehaviors and executive functions tended to among thosefor which Pb was a significant predictor of performance.Following covariate adjustment, higher blood Pbconcentrations at two yr were significantly associated withlower scores on Freedom from Distractibility factor of theWechsler scales, increase in percentage of perseverativeerrors on the Wisconsin Card Sorting Test and theCalifornia Verbal Learning Test.Canfield et al. (2003b,2004)U.S.Design: Prospective longitudinal. 170-174 childrenfrom the Rochester Pb Study were administered anumber of learning and neuropsychologicalfunctioning at 48, 54, and 66 mos of age. At 48 and54 mos the Espy Shape School Task wasadministered while at 66 mos the Working Memoryand Planning assessment protocols of the CambridgeNeuropsychological Test Automated Battery(CANTAB) was given. Extensive measures onmedical and sociodemographic covariates.Serial postnatal blood PbBlood Pb at 2 yrs 9.7 μg/dLLifetime avg blood Pb 7.2(range 0-20) μg/dLFollowing covariate adjustment, blood Pb level at 48 moswas negatively associated withchildren’s focused attentionwhile performing the Shape School Tasks, efficiency atnaming colors, and inhibition of automatic responding.Children with higher blood Pb concentrations alsocompleted fewer phases of the Espy tasks and knew fewercolor and shape names. On the CANTAB battery, childrenwith higher lifetime avg blood Pb levels showed impairedperformance on spatial working memory, spatial memoryspan, and cognitive flexibility and planning. Authorsconclude that the effects ofpediatric Pb exposure are notrestricted to global measures of intellectual functioning andexecutive processes may be at particular risk.

# AX6-18Table AX6-2.5 (cont’d). Effects of Leadon Specific Cognitive Abilities in Children — Attention/Executive Functions,Learning, and Visual-spatial SkillsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited States(cont’d)Ris et al. (2004)U.S.Design: Prospective longitudinal. 195 subjects fromthe Cincinnati Pb Study were administered anextensive and comprehensive neuropsychologicalbattery at 16-17 yrs of age. Domains assessedincluded Executive Functions, Attention, Memory,Achievement, Verbal Skills, Visuoconstructional,and Fine Motor. Factor scores transformed to ranksderived from a principal components factor analysisof the neuropsychological test scores were theprimary outcome variables.Extensive measures onmedical and sociodemographic covariates.Prenatal (maternal) andserial postnatal blood PbassessmentsPrenatal blood Pb 8.3(SD 3.7) μg/dLBlood Pb at 2 yrs 17.4(SD 8.8) μg/dLFollowing covariate adjustment, strongest associationsbetween Pb exposure and performance were observed forfactor scores derived from the Attention component, whichincluded high loadings on variables from the ConnersContinuous Performance Test. This relationship wasstrongest in males. Authors speculate that since theincidence of Attention Deficit/Hyperactivity Disorder isgreater in males in general, early exposure to Pb mayexacerbate a latent potential for such problems.

# AX6-19Table AX6-2.6. Effects of Lead on Disturbances in Behavior, Mood, and Social Conduct in ChildrenReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited StatesSciarillo et al. (1992)U.S.Design: Cross-sectional. 150 2-5 yr-old children inBaltimore separated into “high” (2 consecutive bloodPb levels >15 μg/dL) and “low” groups. Mothersfilled out the Achenbach Child Behavior Checklist(CBCL). The Center for Epidemiologic StudiesDepression Scale (CESD) was administered tomothers as a control measure.Screening blood Pbs atvarious times beforeassessmentHigh group 28.6(SD 9.3) μg/dLLow group 11.3(SD 4.3) μg/dLWhen compared to lower exposed group, children in thehigh group had a significantly higher CBCL TotalBehavior Problems Score (TBPS) and Internalizing andExternalizing scores. After adjustment for maternaldepression, blood Pb concentrations were still significantlyassociated with an increase in the TBPS. Children in highgroup were nearly 3 times morelikely to have a TBPS inthe clinical range. A significantly higher percentage ofchildren in the high group scored in the clinical range forCBCL subscales measuring aggressive and destructivebehavioral tendencies.Bellinger et al. (1994b)U.S.Design: Prospective cohort: 1782 children bornwithin a 1-yr period at a single Boston hospital wereexamined at 8 yrs of age. Teachers filled out theAchenbach Child Behavior Profile (ACBP). Medicaland sociodemographic characteristics assessed byquestionnaire and chart review.Umbilical cord blood PbCord blood Pb 6.8(SD 3.1) μg/dLTooth (dentin) PbTooth Pb 3.4(SD 2.4) μg/gCord blood Pb levels were not associated with theprevalence or nature of behavioral problems reported byteachers. Tooth Pb levels were significantly associatedwith ACBP Total Problem Behavior Scores (TPBS).Statistically significant tooth Pb-associated increases inboth Externalizing and Internalizing scores were observed.Each log unit increase in tooth Pb was associated with a1.5-point increase in T scores for these scales. Authorscaution that residual confounding cannot be ruled outbecause of the lack of information on parentalpsychopathology or observations of the familyenvironment. However, these results are in accord withother studies that social andemotional dysfunction may bean important expression of elevated Pb levels during earlychildhood.Denno (1990)U.S.Design: Prospective cohort. Survey of 987Philadelphia African-American youths enrolled inthe Collaborative Perinatal Project. Data availablefrom birth through 22 yrs of age. Analysisconsidered 100 predictorsof violent and chronicdelinquent behavior.Blood PbValues not providedRepeat offenders presented consistent features such as lowmaternal education, prolonged male-providerunemployment, frequent moves, and higher Pbintoxication. In male subjects, a history of Pb poisoningwas among the most significant predictors of delinquencyand adult criminality.

# AX6-20Table AX6-2.6 (cont’d). Effects of Lead on Disturbances in Behavior, Mood, and Social Conduct in ChildrenReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited States(cont’d)Needleman et al.(1996)U.S.Design: Prospective cohort. 850 boys enrolled in thePittsburgh Youth Study were prescreened to assessdelinquent behavioral tendencies. Subjects whoscored in the 30th percentile on the risk score and anequal number randomly selected from the remainderform the sample of 530 subjects. Measures ofantisocial behavior were administered at 7 and 11 yrsof age including the Self Reported Antisocial Behaviorscale (SRA), Self Reportof Delinquent Behavior(SRD), and parents’ and teachers’ versions of theAchenbach Child Behavior Profile (CBCL). Extensiveassessment of medicaland sociodemographiccovariates.Bone Pb by K-XRFBone Pb (exactconcentrations not reported)Negative values treatedcategorically as 1 andpositive values grouped intoquintiles.Following covariate-adjustment, parents of subjects withhigher Pb levels in bone reported significantly moresomatic complaints, more delinquent and aggressivebehavior, and higher Internalizing and Externalizingscores. Teachers reported significant increase in scores onsomatic complaints, anxious/depressed, social problems,attention problems, delinquent behavior, aggressivebehavior, internalizing and externalizing problems in thehigher bone Pb subjects. At 11 yrs, subject’s SRD scoreswere also significantly related to bone Pb levels. Morehigh Pb subjects had CBCL T scores in the clinical rangefor attention, aggression,and delinquency. Authorsconclude that Pb exposure is associated with increased riskfor antisocial and delinquent behavior.Dietrich et al. (2001)U.S.Design: Prospective longitudinal. 195 subjects fromthe Cincinnati Pb Study were examined at 16-17 yrs ofage. Parents were administered a questionnairedeveloped specifically for the study while CLSsubjects were given the Self Report of DelinquentBehavior. Extensive assessment of medical andsociodemographic covariates.Prenatal (maternal) andserial postnatal blood Pbassessments.Prenatal blood Pb 8.3(SD 3.7) μg/dLBlood Pb at 2 yrs 17.4(SD 8.8) μg/dLPrenatal (maternal) blood Pb was significantly associatedwith a covariate-adjusted increase in the frequency ofparent-reported delinquent and antisocial acts. Prenataland measures of postnatal Pb exposure were significantlyassociated with self-reported delinquent and antisocialbehaviors. Authors concluded that Pb might play ameasurable role in the development of behavioral problemsin inner-city children independent of other important socialand biomedical cofactors.Needleman et al.(2002)U.S.Design: Case-control. 194 adjudicated delinquentsand 146 non-delinquent controls recruited from highschools in the City ofPittsburgh and AlleghenyCounty, PA. Covariate assessments were notextensive but did include race, parentalsociodemographic factors, and neighborhood crimerates.Bone Pb by KXRFCases 11.0 (SD 32.7) μg/gControls 1.5 (SD 32.1) μg/gCases had significantly higher avg concentrations of Pb intibia than controls. Following covariate adjustment,adjudicated delinquents were 4times more likely to havebone Pb concentration >25 μg/g then controls. Bone Pblevel was the second strongest factor in the logisticregression models, exceededonly by race. In modelsstratified by race, bone Pb was exceeded as a risk factoronlyby single parent status. Authors conclude thatelevated body Pb burdens are associated with increasedrisk for adjudicated delinquency.

# AX6-21Table AX6-2.6 (cont’d). Effects of Lead on Disturbances in Behavior, Mood, and Social Conduct in ChildrenReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationEuropeWasserman et al.(1994)YugoslaviaDesign: Prospective longitudinal. Birth cohortof ~300-400 infants followed since birthresiding in two towns in Kosovo, Yugoslavia,one group near a longstanding Pb smelter andbattery manufacturing facility and another in arelatively unexposed location 25 miles away.379 children at 3 yrs of age were examined.Parents were interviewed with the AchenbachChild Behavior Checklist (CBCL). Extensiveassessment of medicaland sociodemographiccovariates.Maternal prenatal, umbilical cordand serial postnatal blood PbMaternal blood Pb in exposedarea 19.9(SD 7.7) μg/dL,unexposed area 5.6(SD 2.0) μg/dLUmbilical cord blood Pb inexposed area 22.2(SD 8.1) μg/dL,unexposed area 5.5(SD 3.3) μg/dLBlood Pb at 2 yrs in exposed area35.4 μg/dL, unexposed area8.5 μg/dLFollowing covariate adjustment, concurrent blood Pb levelswere associated with increased Destructive Behaviors on theCBCL subscale, although the variance accounted for by Pbwas small compared to sociodemographic factors. As bloodPb increased from 10 to 20 μg/dL, subscale scores increasedby 0.5 points. The authors conclude that while statisticallysignificant, the contribution of Pb to social behavioralproblems in this cohort was small compared to the effects ofcorrelated social factors.AustraliaBurns et al. (1999)AustraliaDesign: Prospective longitudinal. 322 subjectsresiding in and near Port Pirie, Australia andfollowed since birth were re-evaluated at 11-13yrs of age. Parents completed the AchenbachChild Behavior Checklist. Extensiveassessment of medicaland sociodemographiccharacteristics.Maternal prenatal, umbilical cordand serial postnatal blood PbAntenatal avg bloodPb 10.1 (SD 3.9) μg/dLUmbilical cord blood Pb9.4 (SD 3.9) μg/dLBlood Pb at 2 yrsgeometric mean 21.3(SD 1.2) μg/dLAfter adjustment for covariates, regression models revealedthat for an increase in avg lifetime blood Pb concentrationsfrom 10 to 30 μg/dL, the Externalizing behavior problem Tscore increased by 3.5 points in boys (95% CI: 1.6, 5.4), butonly 1.8 points (95% CI:!0.1, 11.1) in girls. Internalizingbehavior problems were predicted to rise by 2.1 points (95%CI: 0.0, 4.2) in girls by only 0.8 (95% CI:!0.9, 2.4) in boys.Authors concluded that Pb exposure is associated with anincrease in externalizing (undercontrolled) behaviors in boys.Fergusson et al. (1993)New ZealandDesign: Prospective cohort. 690-891 childrenages 12 and 13 yrs from the Christchurch Childand Health Study, New Zealand were examined.Mothers and teachers were asked to respond toa series of items derived from the Rutter andConners parental and teacher questionnaires.Extensive assessment of sociodemographic andmedical covariates.Tooth (dentine) PbTooth Pb range 3–12 μg/gStatistically significant dose-effect relationships wereobserved between tooth Pb levels and theinattention/restlessness variable at each age. Authorsconclude that this evidence isconsistent with the view thatmildly elevated Pb levels are associated with small but longterm deficits in attentional behaviors.

# AX6-22Table AX6-2.6 (cont’d). Effects of Lead on Disturbances in Behavior, Mood, and Social Conduct in ChildrenReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationAustraliaSilva et al. (1988)New ZealandAs part of the 11-yr follow-up of the DunedinMultidisciplinary Health and Development Study, alongitudinal study of a birth cohort of children bornin Dunedin’s only obstetric hospital, blood Pb levelswere measured in 579 children at age 11 yrs old.The study sample was over-representative of higherSES, but was found to be representative of Dunedinchildren in educational attainment. Blood Pb levelswere examined in association with intelligenceassessed using the WISC-Rand behavioral problemsas assessed by both parents and teachers.Blood Pb at time of testingBlood Pb at age 11 yrs 11.1(SD 4.91, range 4-50) μg/dLLog blood Pb levels were significantly correlated with mostmeasures of behavioral problems, including the Parents’ andTeachers’ Rutter BehavioralScale, the Parents’ andTeachers’ Hyperactivity Scale, and the Teachers’ InattentionScale, after adjustment for various potential confounders. Noassociations were observed between log blood Pb levels andIQ. Authors concluded that exposure to Pb is associated withincreases in children’s’ general behavioral problems,especially in inattention and hyperactivity.

# AX6-23Table AX6-2.7. Effects of Lead onSensory Acuities in ChildrenReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited StatesSchwartz and Otto(1991)U.S.Design: Cross-sectional. 3545 subjects 6-19 yrs oldwho participated in the Hispanic Health andNutrition Examination Survey. Pure toneaudiometric evaluations were performed at 500 Hz,2000 Hz, and 4000 Hz. Extensive measures onmedical and sociodemographic covariates.Blood Pb at the time oftestingBlood Pb 50th percentile8 μg/dLFollowing covariate adjustment, higher blood Pbconcentrations were associated with an increased risk ofhearing thresholds that were elevated above the standardreference level at all four frequencies. Blood Pb was alsoassociated higher hearing threshold when treated as acontinuous outcome. These relationships extended to bloodPb levels below 10 μg/dL. An increase in blood Pb from 6 to18 μg/dL was associated with a 2-dB loss at all frequencies.Authors conclude that HHANES results those reportedearlier for NHANES-II.Dietrich et al. (1992)U.S.Design: Prospective/longitudinal. 215 subjectsdrawn from the Cincinnati PbStudy at the age of 5yrs. Children were administered the SCAN-astandardized test of central auditory processing.Extensive measurement of medical andsociodemographic covariatesPrenatal (maternal) and serialpostnatal blood PbassessmentsPrenatal blood Pb 8.3(SD 3.7) μg/dLBlood Pb at 2 yrs 17.4 (SD8.8) μg/dLHigher prenatal (maternal), neonatal and postnatal blood Pbconcentrations were associated with more incorrectidentification of common monosyllabic words presentedunder conditions of muffling. Following covariateadjustment, avg childhood blood Pb level remainedsignificantly associated with impaired performance on theSCAN subtest. Authors conclude that Pb-related deficits inhearing and auditory processing may be one plausiblemechanism by which an increased Pb burden might impede achild’s learning.EuropeOsman et al. (1999)PolandDesign: Cross-sectional. 155 children 4-14 yr-oldliving in an industrial region of Poland. Pure toneaudiometric evaluations were performed at 500 Hz,1000 Hz, 2000 Hz, 4000 Hz, 6000Hz, and 8000 Hz.Basic data on medical history, limited information onsociodemographic covariates such as familystructure and income.Blood Pb at the timeof testingBlood Pb median 7.2(range 1.9-28) μg/dLHigher blood Pb concentrationswere significantly associatedwith increased hearing thresholds at all frequencies studied.This relationship remained significant when analyses werelimited to subjects with blood Pb levels below 10 μg/dL.Authors conclude that auditory function in children isimpaired at blood Pb concentrations below 10 μg/dL.

# AX6-24Table AX6-2.8. Effects of Lead on Neuromotor Function in ChildrenReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited StatesDietrich et al. (1993b);Bhattacharya et al.(1995); Ris et al.(2004)U.S.Design: Prospective longitudinal. Relationshipbetween Pb exposure and neuromotor function hasbeen examined in several studies on the Cincinnati PbStudy Cohort from 6 to 17 yrs of age. At 6 yrs of age245 subjects were administered the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP); at 6-10 yrs of age subjects were assessed for posturalinstability using a microprocessor-based strain gaugeplatform system and at 16-17 yrs of age the fine-motor skills of study subjects were assessed with thegrooved pegboard and finger tapping tasks (part of acomprehensive neuropsychological battery).Extensive measurement of medical andsociodemographic factors.Prenatal (maternal) andserial postnatal blood PbassessmentsPrenatal blood Pb 8.3(SD 3.7) μg/dLBlood Pb at 2 yrs 17.4 (SD8.8) μg/dLFollowing covariate adjustment, postnatal Pb exposure wassignificantly associated with poorer scores on BOTMPmeasures of bilateral coordination, visual-motor control,upper-limb speed and dexterity and the Fine MotorComposite score. Low-level neonatal blood Pbconcentrations were also significantly associated with poorerscores on the aforementioned subtests, as well as measuresof visual-motor control.Postnatal Pb exposure wassignificantly associated with greater postural instability in 6-10 yr-old subjects and poorer fine-motor coordination whenexamined at 16-17 yrs.Authors conclude that effects of early Pb exposure extendinto a number of dimensions ofneuromotor development.EuropeWasserman et al.(2000a)YugoslaviaDesign: Prospective longitudinal. Birth cohort of~300-400 infants followed since birth residing in twotowns in Kosovo, Yugoslavia, one group near alongstanding Pb smelterand battery manufacturingfacility and another in a relatively unexposed location25 miles away. 283 children at age 54 mos wereadministered the Beery Developmental Test ofVisual-Motor Integration (VMI) and the BruininksOseretsky Test of Motor Proficiency (BOTMP).Extensive measurement of medical andsociodemographic factors.Maternal prenatal, umbilicalcord and serial postnatalblood PbMaternal blood Pb inexposed area 19.9(SD 7.7) μg/dL,unexposed area 5.6(SD 2.0) μg/dLUmbilical cord blood Pb inexposed area 22.2(SD 8.1) μg/dL,unexposed area 5.5(SD 3.3) μg/dLBlood Pb at 2 yrs in exposedarea 35.4 μg/dL, unexposedarea 8.5 μg/dLFollowing covariate-adjustment,the log avg of serial bloodPb assessments to 54 mos was associated with lower FineMotor Composite and VMI scores. Pb exposure wasunrelated to gross motor performance. With covariateadjustment, an increase in avg blood Pb from 10 to 20 μg/dLwas associated with a loss of 0.62 and 0.42 pointsrespectively, in Fine Motor Composite and VMI. Authorsnoted that other factors such as indicators of greaterstimulation in the home make a larger contribution to motordevelopment than Pb.

# AX6-25Table AX6-2.9. Effects of Lead on Direct Measures of Brain AnatomicalDevelopment and Activity in ChildrenReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited StatesTrope et al. (1998)U.S.Design: Case-control. One 10 yr-old subject withhistory of Pb poisoning and unexposed 9 yr-oldcousin. Magnetic Resonance Imaging (MRI) andMagnetic Resonance Spectroscopy (MRS) wereused to assess differences in cortical structures andevidence of neuronal loss. This was the first studyto attempt to determine in vivo structural and/ormetabolic differences in the brain of a childexposed to Pb compared with a healthy control.Blood PbPb poisoned case 51 μg/dLat 38 moUnexposed control notreported.Both children presented with normal volumetric MRI. MRSrevealed a significant alterationin brain metabolites, with areduction in N-acetylaspartate:creatine ratio for both grayand white matter compared to the subject’s cousin. Authorsconclude that results suggestneuronal loss related to earlierPb exposure.Trope et al. (2001)U.S.Design: Case-control. 16 subjects with a history ofelevated blood Pb levels before 5 yrs of age and5 age-matched siblings orcousins were evaluated.Avg age at time of evaluation was 8 yrs. MagneticResonance Imaging (MRI) and MagneticResonance Spectroscopy (MRS) were used toassess differences in cortical structures andevidence of neuronal loss.Blood PbRange in Pb-exposed 23 to65 μg/dLControls <10 μg/dLAll children had normal MRI examinations, but Pb-exposedsubjects exhibited a significant reduction inN-acetylaspartate:creatine and pohosphocreatine ratios infrontal gray matter compared tocontrols. Authors concludethat Pb has an effect on brain metabolites in cortical graymatter suggestive of neuronal loss.Cecil et al. (2005)U.S.Design: Prospective/longitudinal. 48 young adultsages 20 to 23 yrs werere-examined. FunctionalMRI (fMRI) was used to examine the influence ofchildhood Pb exposure on language function.Subjects performed a verb generation/fingertapping paradigm. Extensive measurement ofmedical and sociodemographic covariatesBlood PbAvg childhood blood Pb13.9 (SD 6.6, range4.8-31.1) μg/dLHigher avg childhood blood Pb levels was significantlyassociated with reduced activation in Broca’s area in the lefthemisphere and increased activation in the right temporallobe, the homologue of Wernicke’a area in the lefthemisphere. Authors concludethat elevated childhood Pbexposure strongly influences neural substrates of semanticlanguage function on normal language areas withconcomitant recruitment of contra-lateral regions resulting ina striking dose-dependent atypical organization of languagefunction.

# AX6-26Table AX6-2.9 (cont’d). Effects of Lead on Direct Measuresof Brain Anatomical Development and Activity in ChildrenReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationLatin AmericaRothenberg et al. (2000)MexicoDesign: Prospective/longitudinal. 113 5-7 yr-oldchildren from the Mexico City Prospective Studywere re-examined. Brain stem auditory evokedpotentials were recorded to assess the impact ofprenatal and postnatal Pbexposure on developmentof auditory pathways. Results adjusted for genderand head circumference.Blood PbPrenatal (20 wks) 8.1(SD 4.1) μg/dLCord 8.7 (SD 4.3) μg/dLPostnatal 18 mo 10.8(SD 5.2) μg/dLPrenatal blood Pb at 20 wks was associated with decreasedinterpeak intervals. After fitting a nonlinearmodel to thesedata, I-V and III-V interpeak intervals decreased as blood Pbrose from 1 to 8 μg/dL and increased as blood Pb rose from8 to 30 μg/dL. Increased blood Pb at 12 and 48 mos wasrelated to decreased conduction intervals for I-V and II-Vacross the entire blood Pb range suggesting pathway lengtheffects.AsiaMeng et al. (2005)ChinaDesign: Case-control. 6 subjects with blood Pbconcentrations∃27 μg/dL and 6 controls withblood Pb concentrations <10 μg/dL were evaluatedwith Magnetic Resonance Imaging (MRI) andMagnetic Resonance Spectroscopy to evaluatestructural abnormalities and differences in Nacetylaspartate, creatine, and choline in frontallobes and hippocampus ofcases and controls.Blood PbCases 37.7 (SD 5.7) μg/dLControls 5.4 (SD 1.5)μg/dLAll children presented with normal MRI. Peak values of Nacetylaspartate, choline, and creatine in all four brain regionswere reduced in Pb exposed children relativeto controls.Authors conclude that reducedbrain N-acetylaspartate incases may be related to decreased neuronal density or loss.Reduced choline signal may indicate decreased cellmembrane turnover or myelin alterations while lowercreatine may indicate reduced neuronal cell viability.

# AX6-27Table AX6-2.10. Reversibility of Lead-related Deficits in ChildrenReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited StatesRuff et al. (1993)U.S.Design: Intervention study, non-randomized.126 children with complete data age 13 to 87 mosand with blood Pb levels between 25 and 55 μg/dLwere given chelation with ETDA and/or therapeuticiron where indicated. At baseline and follow-up,patients were evaluated with the Bayley Scales ofInfant Development, Mental Development Index,or Stanford Binet Scales of Intelligence dependingupon age.Blood Pb at time oftreatmentBlood Pb 31.2 (SD 6.5)μg/dLWithout respect to treatment regimen, changes inperformance on cognitive measures after 6 mos weresignificantly related to changes in blood Pb levels aftercontrol for confounding factors. Standardized scores on testsincreased 1 point for every 3 μg/dL decrement in blood Pb.Rogan et al. (2001);Dietrich et al. (2004)U.S.Design: Double blind,placebo-controlledrandomized clinical trial.The Treatment of Pb-Exposed Children (TLC) clinical trial of 780children in 4 centers was designed to determine ifchildren with moderately elevated blood Pbconcentrations given succimer would have betterneuropsychological outcomes than children givenplacebo. Children between 12 and 33 mos of agewere evaluated 3 yrs following treatments andagain at 7 and 7.5 yrs of age. A wide range ofneurological, neuropsychological, and behavioraltests was administered. Assessment of potentiallyconfounding factors included sociodemographicsand parental IQ.Blood PbBaseline blood Pb 26(SD 26.5) μg/dL in bothdrug and placebo groupsSuccimer was effective in lowering blood Pb levels insubjects on active drug during the first 6 mos of the trial.However, after 1 yr differences in the blood Pb levels ofsuccimer and placebo groups had virtually disappears.3 yrs following treatment, nostatistically significantdifferences between active drug and placebo groups wereobserved for IQ or other more focused neuropsychologicaland behavioral measures. Whenevaluated at 7 and 7.5 yrs ofage, TLC could demonstrate nobenefits of earlier treatmenton an extensive battery of cognitive, neurological, behavioraland neuromotor endpoints. Authors conclude that the TLCregimen of chelation therapy is not associated withneurodevelopmental benefits in children with blood Pb levelsbetween 20 and 44 μg/dL and that these results emphasizethe importance of taking environmental measures to preventexposure to Pb in light of the apparent irreversibility of Pbassociated neurodevelopmental deficits.

# AX6-28Table AX6-2.10 (cont’d). Reversibility ofLead-related Deficits in ChildrenReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationUnited States(cont’d)Liu et al. (2002)U.S.Design: Prospective longitudinal clinical trial.Data from the Treatment of Pb-Exposed Children(TLC) used to examine prospective relationshipsbetween falling blood Pb levels and changes incognitive functioning. 741 children recruitedbetween 13 and 33 mos of age were assessed atbaseline and 6 mos later with the Bayley MentalDevelopment Index (MDI) and 36 mos post-randomization with the Wechsler Preschool andPrimary Scales of Intelligence-Revised toobtain IQ.Blood PbBaseline blood Pb 26.2(SD 5.1) μg/dL36 mos post-randomizationblood Pb 12.2 (SD 5.2)μg/dLTLC found no overall effect of changing blood Pb level onchange in cognitive test scores from baseline to 6 mos.Slope estimated to be 0.0 points per 10 μg/dL change inblood Pb. From baseline to 36 mos and 6 mos to 36 mos,falling blood Pb levels were significantly associated withincreased cognitive test scores, but only because of anassociation in the placebo group. Authors conclude thatbecause improvements were not observed in all children, thedata do not provide supportthat Pb-induced cognitiveimpairments are reversible. Although the possibleneurotoxicity of succimer cannot be ruled out.LatinAmericaKordas et al. (2005);Rico et al. (2006)MexicoDesign: Double-blind, placebo-controllednutritional supplementation clinical trial conductedamong 602 1st grade children ages 6-8 yrs inTorreón, Mexico. Subjects received iron, zinc,both or placebo for 6 mos.Parents and teachersfilled out the Conners Rating Scales at baseline andfollow-up six mos following the end ofsupplementation to index behavioral changesfollowing therapy. In addition, 11 cognitive testsof memory, attention, visual-spatial abilities, andlearning were administered, including WISCR-M atbaseline and follow-up 6 mos later.Blood PbBaseline blood Pb 11.5(SD 6.1) μg/dLNo significant effects of treatment on behavior or cognitioncould be detected with any consistency. Authors concludethat this regimen of supplementation does not result inimprovements in ratings of behavior or cognitiveperformance.AustraliaTong et al. (1998)AustraliaDesign: Prospective longitudinal. 375 childrenfrom the Port Pirie Prospective Study werefollowed from birth to the age of 11-13 yrs. BayleyMental Development Index (MDI) at 2 yrs, theMcCarthy Scales General Cognitive Index (GCI)and IQs from the Wechsler Intelligence Scaleserved as the primary indicators of intellectualstatus. The purpose of the study was to assess thereversibility of Pb effects on cognition inrelationship to declines in blood Pb over time.Postnatal blood PbMean blood Pb at 2 yrs21.2 μg/dL declining to7.9 μg/dL at 11-13 yrsAlthough blood Pb levels declined substantially, covariateadjusted scores on standardized measures of intellectualattainment administered at 2, 4,7, and 11-13 yrs of age wereunrelated to declining body burden. Authors conclude thateffects of early exposure to Pb during childhood are notreversed by a subsequent decline in blood Pb concentration.

# AX6-29 

# ANNEX TABLES AX6-3

# AX6-30Table AX6-3.1. Neurobehavioral Effects Associated with Environmental Lead Exposure in AdultsReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationUnited StatesKrieg et al. (2005)1988-1994U.S.4,937 adults aged 20-59 yrs fromNHANES III completed threeneurobehavioral tests.Regression analysesof neurobehaqvioral test and log of bloodPb concentration adjusted for sex, ageeducation, family income, race/ethnicity,computer or videogame familiarity,alcohol use, test language, and surveyphase.Mean blood Pb 3.3 μg/dLRange 0.7 to 41.7 μg/dLNo statistically significant relationship between blood Pb concentrationand mean simple reaction time, symbol-digit substitution latency anderrors and serial digit learning trials to criterion and total score afteradjustments for covariates.Muldoon et al. (1996)U.S.325 women from rural location (mean age71) and 205 women from a city location(mean age 69) participants in the Study forOsteoporotic Fractures had the associationof nonoccupational Pb exposure andcognitive function examined. Logisticregression determined effect of blood Pbon neuropsychological performance.Rural groupBlood Pb 5 μg/dLUrban groupBlood Pb 5 μg/dLGroups were significantly differentwith the urban group more educatedand smoked and drank more. Performance in each group stratified byexposure into three groups (low <4μg/dL, medium 4-7 μg/dL, high>7 μg/dL rural and >8 μg/dL) — no significant associations werepresent in the urban group but the rural group had significantly poorerperformance with increasing blood Pbfor Trails B (OR = 2.6 [95% CI:1.04, 6.49]), Digit Symbol (OR =3.73 [95% CI: 1.57, 8.84]),andReaction Time in the lower (OR = 2.84 [95% CI: 1.19, 6.74]) andupper extremities (OR = 2.43 [95% CI:1.01, 5.83]). The fact thatmarked differences exist between the low Pb groups for rural and urban(the lowest 15th percentile) suggests the differences between the twogroups are unrelated to Pb. Response time for reaction time across Pbgroups increased for the rural group and decreased or remained thesame for the urban group. As response time is sensitive to Pb effect,this raises question whether factors not measured accounted fordifference. Namely MMSE for the whole population was 25 (15-26)with poorer performance in the rural group. The clinical cutoff scorefor MMSE is 24 suggesting the presence of clinical cognitive disorders.Even though this is a simple neuropsychological battery up to 9 wereunable to perform some of the tests including 3 on the MMSE.

# AX6-31Table AX6-3.1 (cont’d). Neurobehavioral Effects Associated with Environmental Lead Exposure in AdultsReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationUnited States(cont’d)Payton et al. (1998)U.S.141 healthy men in VA normal aging studyevaluated every 3 to 5 yrs with cognitivebattery and blood Pb and once ameasurement of patellaand tibia bone Pb.Statistics are confusing as it is not clearwhen ANCOVA is used and how thegroups are created.Mean blood Pb 6 μg/dLMean patella bone Pb 32μg/gMean tibia bone Pb 23 μg/gbone mineralRegressions adjusted for age and education found significantrelationship of blood Pb with Pattern Comparison (perceptual speed),Vocabulary, Word List Memory, Constructional Praxis, BostonNaming Test, and Verbal Fluency Test. Only for Constructional Praxiswere bone Pb and blood Pb significantly associated. Mechanism mostsensitive to low levels Pb exposure believed to be response speed.Vocabulary is significantly associated with blood Pb. Education isnegatively correlated to bone and blood Pb. It is not clear how multiplecomparisons were handledRhodes et al. (2003)U.S.526 participants with mean age 67 yrs,47% had education level of high school orless. Mood symptoms evaluated with BriefSymptom Inventory (BSI). Use of logisticregression adjusting for covariatesexamined association of BSI scales andblood Pb and bone Pb levels.Mean blood Pb 6 μg/dLMean tibia Pb 22 μg/gMean patella Pb 32 μg/gBSI found mood symptoms for anxietyand depression were potentiallyassociated with bone Pb levels.Education was inversely related tobone Pb and high school graduates had significantly higher odds ofGlobal Severity Index andPositive Symptom Total.Wright et al. (2003)U.S.736 healthy men (mean age 68) inNormative Aging Study examined every 3to 5 yrs were administered the MiniMental State Exam (MMSE). Linearregression examined relationship ofMMSE and blood Pb, patella and tibiabone Pb measurements after adjusting forcovariates.Mean blood Pb 5 μg/dL,Mean patella bone Pb 30μg/gMean tibia bone Pb 22 μg/gMean MMSE score 27. Relation ofMMSE scores <24 (n = 41) andblood Pb by logistic regression found OR = 1.21 (95% CI: 1.07, 1.36)and for patella Pb OR = 1.21 (95% CI: 1.00, 1.03) and tibia Pb OR =1.02 (95% CI: 1.00, 1.04). Risk of MMSE <24 when comparing thelowest and highest quartiles of patella Pb was 2.1 (95% CI: 1.1, 4.1),for tibia Pb was 2.2 (95% CI: 1.1, 3.8) and blood Pb was 3.4 (95% CI:1.6, 7.2). Interaction between patella Pb and age, and blood Pb and agein predicting MMSE found steeper decrease in MMSE score relative toage in the higher quartiles ofpatella Pb and blood Pb.MMSE very sensitive to yrs of education below 8 yrs. In this study 213subjects had less than high school education. If the communitydwelling population had older individuals with less education living inareas with higher past pollution the confounding may be impossible tosort out. Initially at beginning ofNAS subjects were eliminated withchronic medical problems or bloodpressure >140/90. It is notaddressed how the development ofmedical conditions during theduration of the study are handled.

# AX6-32Table AX6-3.1 (cont’d). Neurobehavioral Effects Associated with Environmental Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited States(cont’d)Weisskopf et al.(2004b)U.S.466 men, mean age 70 yrs, in the VANormative Aging Study had 2 MMSE tests3.5 yrs apart.Mean blood Pb 4 μg/dLMean patella bone Pb 23μg/gMean tibia bone Pb 19 μg/gBaseline mean MMSE score was 27 and mean change in MMSEscore over 3.5 yrs was 0.3. Change in MMSE associated with oneinterquartile range increment for bone Pb and blood Pb foundrelationship between patella Pb and change in MMSE was unstablewhen patella Pb is∃90 μg/g bone mineral. Examination of patella Pbbelow this level found a greater inverse association with MMSE atlower Pb concentrations (∃=!0.25 [95% CI:!0.45,!0.05]). A similarbut weaker association existed for tibia Pb when values∃67 μg/gbone mineral were removed (∃=!0.19 [95% CI:!0.39, 0.02]). Therewas no association of MMSE change and blood Pb (∃=!0.01 [95%CI:!0.13, 0.11]). There was no interaction of age and bone Pb.These are very high bone Pb levels for environmental exposure. Thebiological plausibility of change in the MMSE over 3.5 yrs wouldhave been reinforced if the change by functional domain in theMMSE was provided.EuropeNordberg et al. (2000)Sweden762 participants, mean age 88 yrs, in a studyof aging and dementia examined MMSE.Used blood Pb as dependent and examinedcontribution of covariates and MMSE.Mean blood Pb 3.7 μg/dL Mean MMSE 25 found norelation of blood Pb and MMSE. In thispopulation was fairly homogenous, all elderly Swedes, and thelikelihood of prior exposure to elevated Pb levels was low.

# AX6-33Table AX6-3.2. Symptoms Associated withOccupational Lead Exposure in AdultsReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationCanadaLindgren et al. (1999)CanadaSmelter workers (n = 467) with a mean ageof 40 yrs completed the Profile of MoodScale. Factor structure of POMS validated inthis occupational population. Regressionanalysis determined association with Pbexposure.Mean (SD, range) blood Pb28 (8.5, 4-62) μg/dLMean (SD, range) IBL 711(415.5, 1-1537) μg·yr/dLFactor analysis found one factor labeled “general distress” composedof POMS subscales anger, confusion, depression, fatigue and tensionand a second factor labeled ‘psychological adjustment.’ IBL wassignificantly associated with ‘general distress’ after adjustment for thecovariates (∃= 0.28 [SE 1.51Η10!4], p = 0.01) while there was norelation with blood Pb. The factorstructure of POMS originallyvalidated in a clinical populationhad six mood subscales however thefactor structure in this occupational population was found to haveonly two subscales.Holness et al. (1988)Canada47 demolition workers with acute Pbintoxication - Phase 1 - were followed withblood Pb and symptoms during engineeringmodifications to control exposure –Phases 2-4. Workers stratified by blood Pband symptom frequency was analyzed.Phase I - Mean blood Pb59 μg/dLPhase 2 - Mean blood Pb30 μg/dLPhase 3 - Mean blood Pb19 μg/dLPhase 4 - Mean blood Pb17 μg/dLBelow blood Pb <50 μg/dL, workers reported symptoms of fatigue(25%), headache (14%), dizzy (9%), sleep (8%), abdominal cramps(8%), muscle ache (8%), paresthesiae (8%), appetite (7%),constipation (6%), and weakness (6%). All symptoms weresignificantly lower except for paresthesiae when compared to groupwith blood Pb >70 μg/dL. Of interest, at beginning of Phase 4 whenmean blood Pb was 13 μg/dL, no symptoms were reported. At theend of Phase 4, mean blood Pb was 17 μg/dL and one workercomplained of fatigue.EuropeLucchini et al. (2000)Italy66 workers in Pb manufacturing, mean age40 (8.7) yrs and 86 controls mean age 43(8.8) yrs were administered a questionnairewith neuropsychological (14 items), sensorymotor (3 items), memory (4 items) andextrapyramidal (8 items), 10 Parkinsonsymptoms and the Mood Scale. Groupcomparisons and linear regression examinedrelationship of symptoms and Pb exposure.Pb workersMean (SD, range) blood Pb27 (11.0, 6-61) μg/dLMean (SD, range) TWA 32(14.1, 6-61) μg/dLMean (SD, range) IBL 410(360.8, 8-1315) μg·yr/dLControlsMean (SD, range) blood Pb8 (4.5, 2-21) μg/dLPb exposed worker reported confusion, somnolence, abnormalfatigue, irritability, and muscular pain more frequently (p < 0.04).There were no group differences for the parkinsonism symptoms orMood Scale. Linear regression combing exposed and control groupfound neurological symptoms significantly associated with blood Pbr = 0.22, p = 0.006). Neuropsychological symptoms weresignificantly higher in the High-IBL compared to the Low-IBL group.The estimated threshold for a significant increase (prevalence of 5%)of a high score for neurological symptoms was at a blood Pb of12 μg/dL.

# AX6-34Table AX6-3.2 (cont’d). Symptoms Associated with Occupational Lead Exposure in AdultsReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationLatin AmericaMaizlish et al. (1995)Venezuela43 workers from a Pb smelter, mean age 34(9) yrs and 47 nonexposed workers, meanage 35 (11) yrs completed the profile ofmood states (POMS) questionnaire and aquestionnaire of symptoms of the central andperipheral nervous system, andgastrointestinal. Prevalence ratios used toexamine symptoms and Pb. ANCOVA andlinear regression adjusting for potentialconfounders examined relationship of Pbexposure and POMS.Pb workersMean (SD) blood Pb 43(12.1) μg/dLMean (SD) peak blood Pb60 (20.3) μg/dLMean (SD) TWA 48 (12.1)μg/dLControlsMean (SD) blood Pb 15 (6)μg/dLMean (SD) peak blood Pb15 (6) μg/dLMean (SD) TWA 15 (SD 6)μg/dLSignificantly increased relative risks found for difficultyconcentrating (RR = 1.8 [95% CI: 1.0, 3.1]), often being angry orupset without reason (RR = 2.2 [95% CI: 1.2, 4.1]), feelingabnormally tired (RR = 2.2 [95% CI: 0.9, 5.3]) and joint pain(RR = 1.8 [95% CI: 1.0, 3.3]).The six subscales of the POMS werenot significantly different betweenthe exposed and control groups.However dose-related analysis found significantly poorer scores fortension-anxiety and blood Pb (p = 0.009), hostility and blood Pb(p = 0.01) and TWA (p = 0.04), and depression and blood Pb(p = 0.003) and peak Pb (p = 0.003) and TWA (p = 0.004).AsiaSchwartz et al.(2001a)Korea803 Pb-exposed Korean workers, mean age40 yrs completed the Center forEpidemiologic Studies Depression Scale.Linear regression examined for associationof CES-D and Pb biomarkers after adjustingfor the covariates.Mean (SD) blood Pb 32(15.0) μg/dLMean (SD) tibia Pb 37(40.3) μg/g bone mineralAfter adjustment for age, gender and education significantassociations found for CES-D and tibia Pb (∃= 0.0021 [SE 0.0008];p < 0.01) but not with blood Pb. This occupational Pb-exposedpopulations had higher past Pb exposure compared to the currentmean blood Pb of 32 μg/dL.Lee et al. (2000)Korea95 Korean Pb exposed workers, mean age 43yrs, completed questionnaire of Pb-relatedsymptoms present over last three mos.Relationship between symptom score andmeasures of Pb exposure assessed by linearregression. Logistic regression use to modelpresence or absence of symptoms forgastrointestinal, neuromuscular, and general.DMSA-chelatable Pb Mean(SD) 289 (167.7) μgMean (SD) ZPP 108 (60.6)μg/dLMean (SD) ALAU3 (2.8)mg/LMean(SD) blood Pb 45(SD 9.3) μg/dLWorkers with DMSA-chelatable Pb above the median of 261 μg were6.2 (95% CI: 2.4, 17.8) times more likely to have tingling ornumbness in their extremities, 3.3 (95% CI: 1.2, 10.5) times morelikely to experience muscle pain and 3.2 (95% CI: 1.3, 7.9) timesmore likely to feel irritable. The workers with higher chelatable Pbwere 7.8 (95% CI: 2.8, 24.5) times more likely to experienceneuromuscular symptoms compared to workers with lower chelatablePb. In this study ZPP predicted weakness of ankle and wrist(OR = 2.9 [95% CI: 1.1, 8.1]) and fatigue (OR = 2.9 [95% CI:1.1, 8.7]) while ALAU predicted inability to sleep (OR = 5.4 [95%CI: 1.2, 33.2]) and blood Pb was not significantly associated with anysymptoms. A measure of Pb in bioavailable storage pools was thestrongest predictor of symptomsparticularly neuromuscular.

# AX6-35Table AX6-3.2 (cont’d). Symptoms Associated with Occupational Lead Exposure in AdultsReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationAsia(cont’d)Niu et al. (2000)China44 Pb-exposed workers (17 men, 27 women)from Pb printing houses, mean age 35 (4.9)and education 9.3 (no SD) yrs and 34controls (19 men and 15 women), mean age33 (7.4) yrs and education 9.5 (no SD) yrscompleted the profile of mood state as part ofthe NCTB. ANCOVA controlling for age,sex and education examined groupdifferences and linear regression for dose-response relationship.Mean blood Pb 29(SD 26.5) μg/dL(8 workers blood Pbexceeded 50 μg/dL)ControlsMean blood Pb 13(SD 9.9) μg/dL(1 control blood Pbexceeded 50 μg/dL)POMS subscales for confusion (F = 3.02, p < 0.01), fatigue (F = 3.61,p < 0.01), and tension (F = 2.82, p <0.01) were significantly elevatedin the Pb exposed group. Regression analyses found a dose response(data not shown).

# AX6-36Table AX6-3.3. Neurobehavioral Effects Associated with Occupational Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited StatesFiedler et al. (2003)New Jersey40 workers with Pb exposure, mean age48 (9.5) yrs completed a neurobehavioralbattery and was compared to 45 Pb/solventworkers, mean age 47 (10.2), 39 solventexposed workers, mean age 43 (9.4), and33 controls, mean age 44 (10.2). Groupdifferences and dose-effect relationshipswere assessed after adjusting for potentialconfounding.Mean (SD) blood Pbμg/dL; mean (SD) bone Pbppm (dry weight)Pb workers14 (11.7); 2.7 (0.7)Pb/Solvent workers12 (11.6); 2.8 (0.6)Solvent workers5 (4.1);!1.8 (1.8)Controls4 (1.4);!1.1 (1.6)Of nineteen outcomes, significant differences found on the Californiaverbal learning test (CVLT) (p= 0.05) and positive symptom distressindex on the Symptom checklist-90-R. On the CVLT the controlsperformed significantly better ontrials 2 and 3 demonstratingefficiency of verbal learning.Symbol digit substitution (SDS)approached significance (p = 0.09) with Pb and Pb/solvent groupslower on latency of response but not accuracy. Bone Pb was asignificant predictor of latency ofresponse on SDS, total errors onpaced auditory serial addition task and simple reaction time non-preferred hand. Bone Pb and SRT, preferred hand approachedsignificance. This is a confusing study design as bone Pb is used as apredictor in workers both with andwithout occupational Pb exposure.CanadaLindgren et al. (1996)Canada467 Canadian former and current, Frenchand English speaking Pb smelter workers,mean age 43 (11.0) yrs and education10 (3.2) yrs were administered aneuropsychological battery in English orFrench. Data analyses used MANCOVAadjusting for age, education, measure ofdepressive symptoms and self reportedalcohol use.Mean (SD) yrs employment18 (7.4)Mean (SD) blood Pb 28(8.4) μg/dLMean (SD) TWA 40(4-66) μg/dLMean (SD) IBL 765(1-1626) μg·yr/dLFourteen neuropsychological variables examined by MANCOVAwith the grouping variable exposure (high, medium and low) and thecovariates, age, education, CES-D,and alcohol use found no exposureterm significant until yrs of employment, a suppressor term, wasadded as a covariate. IBL exposure groups differed significantly (df2,417) on digit symbol (F = 3.03, p= 0.05), logical memory (F = 3.29,P = 0.04), Purdue dominant hand (F = 4.89, p = 0.01), and trails A(F = 3.89, p = 0.02) and B (F = 3.2,p = 0.04). This study showed adose-effect relationship betweencumulative Pb exposure (IBL) andneuropsychological performanceat a time when there was noassociation with current blood Pb.

# AX6-37Table AX6-3.3 (cont’d). Neurobehavioral Effects Associated with Occupational Lead Exposure in AdultsReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationCanada(cont’d)Bleecker et al. (2002)Canada256 smelter workers from the abovepopulation were currently employed andtook the test battery in English. Their meanage was 41 (7.9) yrs, and education 10 (2.8)yrs. The goal was to determine ifeducational achievement as measured byWRAT-R Reading modified performance onMMSE. Linear regression assessed thecontribution of age, WRAT-R, education,alcohol intake, cigarette use, IBL andIBLΗWRAT-R on MMSE performance.Mean (SD) blood Pb 28(8.8) μg/dLMean (SD) IBL 725 (434)μg·yr/dLMMSE had a median (range) score of 29 (19-30). The most commonerrors were recall of 3 items (38%), spell world backwards (31%),repetition of “no ifs ands or buts” (21%) and copy a design to twointersecting pentagons (16%). WRAT-R reading used as an additionalmeasure of educational achievement because it was a stronger predictorof MMSE performance than yrs of education. The significantinteraction (♠R2= 2%, p = 0.01)explained by a dose-effect betweenIBL and MMSE only in the 78 workers with a WRAT-R reading gradelevel less than 6. The workers with higher reading grade levels and thesame cumulative Pb exposure were able to compensate for the effectsof Pb on the MMSE because of increased cognitive reserve.Bleecker et al. (2005a)Canada256 smelter workers currently employed andtook the test battery in English. Their meanage was 41 (7.9) yrs, and education 10 (2.8)yrs. The purpose was to determine whethercomponents of verbal memory as measuredon the Rey Auditory Verbal Learning Test(RAVLT) were differentially affected by Pbexposure. Linear regression and ANCOVAassessed the relationship of Pb andcomponents of verbal learning and memory.Mean (SD) blood Pb 28(8.8) μg/dLMean (SD) TWA 39 (12.3)μg/dLMean (SD) IBL 725 (434)μg·yr/dLOutcome variables RAVLT a word list test included measures ofimmediate memory span and attention (Trial 1), best learning (Trial V),incremental learning across the five trials (Total Score), and storage(Recognition) and retrieval (DelayedRecall) of verbalmaterial. TWAsignificantly contributed to the explanation of variance for Trial V(♠R2= 1.4%, p < 0.03) and Delayed Recall (♠R2= 1.4%, p = 0.03)after adjusting for age and WRAT-R while IBL did the same withRecognition (♠R2= 2.0%, p = <0.02) and Delayed Recall(♠R2= 1.1%, p = 0.06). Workers stratified into 3 group by increasingclinical memory difficulties-Group1had normal encoding, storage andretrieval; Group2 could encode andstore verbal information but haddifficulty with retrieval and Group 3 had abnormal encoding, storageand retrieval but was still able to learn new verbal information.ANCOVA adjusting for age and WRAT-R compared Pb exposureacross the memory groups. Blood Pb showed no difference but TWAand IBL were significantly higher in Group 3 compared to Group 1(p < 0.05 for both). Internal strategies used on the RAVLT over thefive trials found that Groups 1 and 2 remembered more words from thebeginning of the list while group 3 remembered more from the end.At a time when blood Pb was notassociated with performance,cumulative Pb exposure resulted inpoorer storage and retrieval ofpreviously learned material. Alterations in the ability to organizematerials in long term memory interferes with retrieval efficiency.

# AX6-38Table AX6-3.3 (cont’d). Neurobehavioral Effects Associated with Occupational Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationCanada(cont’d)Bleecker et al. (1997a)New Brunswick1992-1993The performance of the 467 current and retiredsmelter workers as described in Lindgren et al.(1996) administered a screeningneuropsychological battery by testers blindedto the degree of Pb exposure of the worker hadtheir performance compared to age matchednorms. If performance on two or more tests inany functional domain was below 1.5 standarddeviations the worker was invited for acomplete clinical evaluation. Eighty currentworkers were identified by this criterion.Mean yrs - age 44 (8.4) yrs, education 8 (2.8)yrs and duration employed 20 (5.3) yrs. Fiveneuropsychological testscommonly associatedwith Pb exposure were examined for adifferential association with blood Pb,IBL,TWA and bone Pb.Mean (SD) blood Pb 26(7.07) μg/dLMean (SD) TWA 42(8.4) μg/dLMean (SD) IBL 903(305.9) μg·yr/dL,Mean (SD) tibial bone Pb41 μg/g bone mineralRelationship of 5 neuropsychologicaltests with 4 measures of Pb doseafter adjusting for age age2and education,education2found RAVLT trialV and Verbal Paired Associates were associated with blood Pb(♠R2= 6.2%, p = 0.02;♠R2= 5.5%, p = 0.07) and TWA (♠R2= 3.2%,p = 0.09;♠R2= 13.9%; P = 0.00) while Digit Symbol and GroovedPegboard were associated with TWA (♠R2= 6.1%, p = 0.00;♠R2= 5.5%,p = 0.02) and IBL (♠R2= 4.8%, p = 0.01;♠R2= 5.7%, p = 0.02). Onlygrooved pegboard was associated with bone Pb (♠R2= 4.2%, p = 0.05).Block design was not associated withany measures of Pb dose. Age wasan effect modifier with grooved pegboard. There was enhanced slowing inolder workers when compared to younger workers with the identical IBL.Bleecker et al. (1997b)New Brunswick1992-1993Of the 80 current smelter workers describedabove 78 completed a simple visual reactiontime (SRT) and had mean yrs age 44 (8.2) yrs,education 8 (7.2) yrs and duration employed20 (5.6) yrs.Mean (SD) blood Pb, 26(7.2) μg/dLMean (SD) blood Pb frombone 7 (4.2) μg/dLMean (SD) blood Pb fromenvironment 19(7.0) μg/dLMean (SD) bone Pb 40(25.2) μg/g bone mineralSRT consisted of 44 responses to avisual stimulusat interstimulusintervals (ISI) varying between 1 through 10 seconds with a mean SRT(median) of 262 (179 to 387) ms. Blood Pb and median SRT had acurvilinear relationship R2= Pb+ Pb2, 13.7%, p < 0.01) after adjusting forage and education with slowing of SRT beginning at a blood Pb of~30 μg/dL. No relationship existedbetween bone Pb and SRT. There wasa stronger association between Pb and Pb2and SRT for the longer ISIs of 6to 10 seconds (R2= 13.9%, p < 0.01), as age was significantly related tothe shorter ISI = s but not the longer ones. In this population thecontribution of bone Pb to blood Pb had been previously where estimatedwhere for a bone Pb level of 100 μg Pb/g bone mineral, 17 μg Pb/dL of theblood Pb was derived from internal bone stores with the remainder fromthe environment. Blood Pb was fractionated to that from bone (blood Pbbn) vs. blood Pb from the environment (blood Pb-en). Regression analysisto examine the relationship of blood Pb-bn and blood Pb-en and SRT afteradjusting for the covariates found significant contribution to the varianceof SRT only for blood Pb-en (R2for blood Pb-en + blood Pb-en2= 14.4%,p < 0.01). The absence of a contribution by age and more stable responseswith ISIs of 6 to 10 sec supportsusing this component of SRT.

# AX6-39Table AX6-3.3 (cont’d). Neurobehavioral Effects Associated with Occupational Lead Exposure in AdultsReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationCanada(cont’d)Lindgren et al. (2003)New Brunswick1992-1993In an attempt to separate the effects of pasthigh Pb exposure from a lower proximateexposure, examination of the pattern of Pblevels of the 467 Canadian Pb smelterworkers found 40 workers who had high pastexposure followed by yrs where 90% ofblood Pb were above 40 μg/dL (High-High = H-H) while another group of 40workers had similar past high Pb exposurefollowed by yrs where 90% of blood Pb werebelow 40 μg/dL (High-Low = H-L). Thegroups did not differ on age, education, yrsof employment or CES-D. Five outcomesexamined-Purdue Pegboard assembly,Block Design, Digit Symbol, Rey AuditoryVerbal Learning Test-total score, delayedLogical Memory.Mean (SD) IBL for pastexposureH-H 633 (202.2) μg·yr/dLH-L 557 (144.8) μg·yr/dLMean (SD) IBL for theproximate exposureH-H 647 (58.7) μg·yr/dLH-L 409 (46.4) μg·yr/dLMean (SD) blood PbH-H 37 (5.1) μg/dLH-L 24 (5.2) μg/dLOf the five neuropsychologicalmeasures examined only RAVLT(total score) and Logical Memory(delayed) were significantlydifferent after adjusting for the covariates in the two pattern groups.Use of regression analyses found pattern group contributedsignificantly (R2= 4%, p < 0.05) to the explanation of variance inRAVLT after accounting for current blood Pb (R2= 3%, p < 0.10) andIBL measures (R2= 7%, p < 0.01). For past IBL, H-H patterncorrelated more strongly with RAVLT (r =!0.21) while H-L patternhad no relationship with past exposure (r = 0.08). For proximate IBLthe difference was maintained between H-H (r =!0.11) and H-Lpattern (r = 0.00). The authors suggested that the absence of anassociation between past high Pb exposure and verbal memory in theH-L pattern group may reflect reversibility of function when blood Pbis maintained below 40 μg/dL.Braun and Daigneault(1991)Quebec41 workers from a secondary Pb smelter,mean age 35 (9.6) yrs and yrs of education10 (2.1) were compared to a control groupmean age 37 (10.1) yrs and yrs of education11 (1.3) on tests of cognitive and motorfunction. MANCOVA and dose-effectrelationships after adjusting for potentialconfounders were performed.Mean (SD) TWA 53(7.5) μg/dLMean (SD) maximumblood Pb 87 (22.4) μg/dLNone of the measures of cognitive executive function showed groupdifferences. Partial correlation adjusting for age and education withdose related variables found no statistical significance. On motorfunction the exposed workers had significantly slower simple reactiontime (p = 0.05). However partial correlations with measures of dosefound dose-effect correlation in bothnegative and positive directions.Group of exposed workers was mixed for Pb exposure with 11currently working and the remainderwith no exposure up to 84 mos.Also two of the exposed workers had been treated with chelation.

# AX6-40Table AX6-3.3 (cont’d). Neurobehavioral Effects Associated with Occupational Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationEuropeH≅nninen et al. (1998)FinlandFifty-four Pb battery workers werestratified by those whose blood Pb neverexceeded 50 μg/dL (n = 26) (group 1)and those who had higher exposure in thepast (n = 28) (group 2) to examine theneuropsychological effects of current lowlevel blood Pb from higher blood Pb inthe past. Mean age group 1was 42 (9.3)yrs, education 8 (1.7) yrs and yrs ofexposure 12 (6.7). Mean age group 2 was47 (6.2) yrs, education 8 (1.0) yrs and yrsof exposure 21 (6.9). Analysis includedpartial correlations within the groups andANCOVA within group 1 divided at themedian TWA3 of 29 μg/dL.Group 1Mean IBL 330 μg·yr/dLMaximum blood Pb 40 μg/dLTWA 29 μg/dLTibial Pb 20 μg/gCalcaneal Pb 79 μg/gGroup 2Mean IBL 823 μg·yr/dLMaximum blood Pb 69 μg/dLTWA 40 μg/dLTibial Pb 35 μg/gCalcaneal Pb 100 μg/gIBL, TWA and maximumblood Pb were also calculatedfor the previous 3 yrs with amedian TWA3 of 29 μg/dLPartial correlations controlling for age, sex and education in group 1found block design, digit symbol, digit span, similarities, Santa Ana 1and memory for design significantly associated with recent measuresof exposure and embedded figureswith maximum blood Pb. In group2 embedded figures, digit symbol, block design, and associativelearning were associated with IBL and /or maximum blood Pb.Calcaneal Pb was weakly associated with digit symbol, digit symbolretention, and synonyms. There was no association with tibial Pb ineither group. Group 1 divided at the median TWA3 of 29 μg/dLfound the high group had lower scores for visuospatial andvisuoperceptive tasks (digit symbol, embedded figures and memoryfor design). Overall past high exposure, blood Pb >50 μg/dL, had thegreatest effect on tests requiring the encoding of complex visuallypresented stimuli. Theauthors conclude that the effect of Pb on brainfunction is better reflected by history of blood Pb than content of Pbin bone.Lucchini et al. (2000)Italy66 workers in Pb manufacturing, meanage 40 (8.6) yrs, mean education 8 ( 2.4)yrs and mean exposure time 11 (9) yrsand a control group of 86 with mean age43 (8.8) yrs, mean yrs of education 9(2.7) yrs. Group differences examinedand dose-effect relationship withcorrelation and ANOVA.Pb workersMean (SD) blood Pb 28(11) μg/dLMean (SD) IBL 410(360.8) μg·yr/dLMean (SD) TWA 32(14.1) μg/dLMean (SD) yrs exposed11(8.1)ControlMean (SD) blood Pb 84.5) μg/dLNo association with neuropsychological tests (addition, digit span,finger tapping symbol digit and motor test from Luria) and blood Pb,TWA or IBL were found. Blood Pb andvisual contrast sensitivities atthe high frequencies were significantly associated for the entire group.Blood Pb and serum prolactin in the whole group was significantlyassociated. Increased prolactin secretion occurs with a variety ofneurotoxins and reflects impaireddopamine function in the pituitary.The estimated threshold for a significant increase of high prolactinlevels was at a blood Pb of 10 μg/dL.

# AX6-41Table AX6-3.3 (cont’d). Neurobehavioral Effects Associated with Occupational Lead Exposure in AdultsReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationEurope(cont’d)_sterberg et al. (1997)Sweden38 workers, median age 42 (no range) yrs ata secondary smelter stratified by finger bonePb concentration and along with 19 controlsmatched triplets for age, education and joblevel. Median yrs employed 10 (2-35).High bone PbMedian (range) bone 32(17-101) μg/gMedian (range) blood Pb38 (19-50) μg/dLMedian (range) peak bloodPb 63 (46-90) μg/dLMedian (range) IBL 408(129-1659) μg·yr/dLLow bone PbMedian (range) bone 16(!7 to 49) μg/gMedian (range) blood Pb34 (17-55) μg/dLMedian (range) peak bloodPb 57 (34-78) μg/dLMedian (range) IBL 250(47-835) μg·yr/dLControlsMedian (range) bone 4(!19 to 18) μg/gMedian (range) blood Pb 4(1-7) μg/dLA cognitive test battery (36 tests) covering learning and memory,visuomotor function,visuospatial function, concentration andsustained attention found no impairment or dose-responserelationships with any of the markers of Pb exposure. Deviating testscores (belong to 10% lowest reference norms) were less in highbone Pb (1 vs. 4 vs. 4). None ofthe deviating parameters weresignificantly correlated with any of the Pb indices. Even when agewas taken into account the significant associationsbetween outcomeand Pb exposure metrics did not exceed chance in light of thenumerous analyses performed. These were the most heavily Pbexposed workers in Sweden. Itwas unusual that the 2 visuomotortasks significantly different hadbetter performance in the Pbexposed workers compared to the controls.

# AX6-42Table AX6-3.3 (cont’d). Neurobehavioral Effects Associated with Occupational Lead Exposure in AdultsReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationEurope(cont’d)Stollery et al. (1991)EnglandSeventy Pb-exposed workers, mean age41(no SD) yrs, grouped by blood Pb(<20 μg/dL, 21-40 μg/dL and 41-80 μg/dL)examined on three occasions each separatedby four mos. Tested on a computer forsyntactic reasoning, delayed five choicereaction time, visual spatial memory, andcategory search task.Low blood PbMean blood Pb 14 μg/dLMean ZPP 13 mg/dLMean urinary ALA 2 mg/LMean yrs exposed 7Medium blood PbMean blood Pb 31 μg/dLMean ZPP 33 mg/dLMean urinary ALA 3 mg/LMean yrs exposed 10High blood PbMean blood Pb 52 μg/dLMean ZPP 77 mg/dLMean urinary ALA 6 mg/LMean yrs exposed 11Pb exposure was stable over the 8 mos of testing. The low Pb groupdrank significantly less alcohol and rated their work as lessdemanding. Performance and exposure stable except in the high Pbgroup where decision time was slowed more than movement timealong with concentration difficulties that remained stable acrosstesting sessions. Movement and decision times were significantlycorrelated for each duration of waiting. On the memory test ofrecalled nouns, the memory deficit associated with Pb (r =!0.35,p = 0.003) was restricted to recall of nouns unrelated to task(distracters) (p = 0.04) that did not improve with repetition suggestiveof difficulties with incidental learning. Workers with blood Pb>40 μg/dL had impairments that correlated best with avg blood Pbover the preceding 8 mos. Workers with blood Pb between 21 to40 μg/dL had essentially no impairment.Stollery (1996)EnglandSame as above except this was a furtheranalysis of the five choice reaction time.Same as above Movement and decisionslowing was correlated with blood Pb.Slowed movement time was constant across response-stimulusintervals in contrast to decision time that was increasingly affected byPb especially at the shortest response-stimulus intervals.This supported the finding that decision gaps, central in origin, asopposed to movement gaps are selectively affected by Pb exposure inthis population.Barth et al. (2002)Austria47 Pb storage-battery workers, mean age40 (9.7) yrs and 53 nonexposed controls,mean age 39 (8.4) yrs were matched for ageand verbal intelligence. Group differencesand dose-response relationship wereexplored.Pb workersMean (SD) blood Pb 31(11.2) μg/dLMean (SD) IBL 384(349.0) μg·yr/dLMean (SD) yrs employed12 (9.0)ControlsMean (SD) blood Pb 4(2.0) μg/dLSignificant differences were found for block design (p#0.01), visualrecognition (p#0.01) and Wisconsin card sorting (categoriesp = 0.0005, total errors p = 0.0025, perseverations p = 0.001, loss ofsorting principle p = 0.003) but not SRT or digit symbol. In theexposed group partial correlation adjusting for age found nosignificant associations with IBL (n = 53). In the entire group the fullcorrelation was significant for blood Pb and Wisconsin card sorting,block design and visual recognition(n = 100). Visuospatial abilitiesand executive function were better predicted by blood Pb thancumulative Pb exposure. It is unusual that a frontal lobe task isassociated with blood Pb when SRT and digit symbol sensitive to theaffects of Pb are not.

# AX6-43Table AX6-3.3 (cont’d). Neurobehavioral Effects Associated with Occupational Lead Exposure in AdultsReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationEurope(cont’d)Winker et al. (2005)Austria48 workers formerly Pb-exposed, meanduration since last exposure 5 (3.5) yrs, andmean age 40 (8.8) yrs were matched with 48controls for age, verbal intelligence, yrs ofeducation and number of alcoholic drinks.Group differences and dose-responserelationship were explored.Formerly Pb-exposedMean (SD, range) blood Pb5.4 (2.7, 1.6-14.5) μg/dLMean (SD) IBL 4153.3(36930.3) μg·yr/dLControlsMean (SD, range) blood Pb4.7 (2.5, 1.6-12.6) μg/dLNo significant differences on neurobehavioral battery were presentwhen groups compared by t-tests for paired samples. When thegroups were combined, partial correlation adjusting for age foundsignificant negative correlation between blood Pb and Block Design,(r =−0.28, p < 0.01) Visual Recognition (r =−0.21, p < 0.05) andDigit Symbol Substitution (r =−0.26, p < 0.01). The authorsconclude that the cognitive deficits associated with low-level Pbexposure are reversible. However there appears to be a residual effectprimarily from those with thehighest past Pb exposure.Winker et al. (2006)AustriaThe same 48 workers formerly Pb-exposeddescribed above were compared to the47 exposed workers described by Barth et al.(2002). Both groups were comparable forage and verbal intelligence. Groupdifferences and differences by duration ofexposure and exposure absence wereevaluated.Exposed workersMean (SD, range) blood Pb31 (11.2, 10.6-62.1) μg/dLMean (SD) IBL 4613(4187.6) μg·yr/dLFormerly Pb-exposedMean (SD, range) blood Pb5.4 (2.7, 1.6-14.5) μg/dLMean (SD) IBL 4153.3(36930.3) μg·yr/dLMann-Whitney test found significantly better performance in theformerly Pb-exposed workers for Block Design (p = 0.005) andWisconsin Card Sorting Test (categories p = 0.0005, total errorsp = 0.005, perseverations p = 0.0095 and loss of sorting principlep = 0.02). To further examine the reduction of cognitive impairmentwith absence of exposure, workers were stratified by duration ofexposure and exposure absence – short exposure and long absence;long exposure and long absence; short exposure and short/no absenceand long exposure and short/no absence. Linear contrasts for BlockDesign (p = 0.003) and WisconsinCard Sorting Test (categoriesp < 0.001, total errors p = 0.001, perseverations p = 0.019 and loss ofsorting principle p = 0.030) were highly significant in thehypothesized direction. Results were believed to support reversibilityof cognitive deficits relatedto occupational Pb exposure.

# AX6-44Table AX6-3.3 (cont’d). Neurobehavioral Effects Associated with Occupational Lead Exposure in AdultsReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationLatin AmericaMaizlish et al. (1995)Venezuela43 workers from a Pb smelter, mean age 34(9) yrs and 47 nonexposed workers, meanage 35 (11) yrs completed the WHOneurobehavioral coretest battery. ANCOVAand linear regression adjusting for potentialconfounders examined relationship of Pbexposure and NCTB.Pb workersMean (SD) blood Pb 43(12.1) μg/dLMean (SD) peak blood Pb60 (20.3) μg/dLMean (SD) TWA 48(12.1) μg/dLControlsMean (SD) blood Pb 15(6) μg/dLMean (SD) peak blood Pb15 (6) μg/dLMean TWA 15 (6) μg/dLGroup comparison was significant for SRT (p = 0.06) but the Pbexposed workers performed faster. Linear regression found SRTpoorer performance with blood Pband TWA but not significant.With peak blood Pb SRT improvedwith increasing Pb exposure.In this study only symptoms weresignificantly different betweenthe groups.AsiaSchwartz et al.(2001a)South Korea803 Korean Pb-exposed workers, 80% menand 20% women, mean age 40 (10.1) yrsfrom a variety of industries, and 135controls, 92% men and 8% women, meanage 35 (9.1) yrs. Educational levels Pbexposed workers/controls#6 yrs = 23% / 7%, 7-9 yrs 23% / 11%, 10-12 yrs = 46% / 70%, and >12 yrs 8% / 12%.Group differences on neurobehavioral testingafter controlling for covariates and linearregression controlling for covariatesexamined the presence of a dose-effectrelationship.Pb workersMean (SD) blood Pb 32(15) μg/dLMean (SD) tibia bone Pb37 (40.3) μg/gMean (SD) DMSAchelatable Pb level 186(208.1) μgControlsMean (SD) blood Pb 5(1.8) μg/dLMean (SD) Tibia bone Pb 6(7) μg/gNineteen outcomes examined. Compared to controls Pb exposedworkers performed significantly worse on SRT, Digit Span, BentonVisual Retention, Colored Progressive Matrices, Digit Symbol, andPurdue Pegboard after controlling forage, gender and education. Theassociation of DMSA with test performance was lost by the additionof blood Pb. Bone Pb was not associated with neurobehavioralperformance. Blood Pb was thebest predictor for significantdecrements in neurobehavioralperformance on trails B (∃=!0.0025[SE 0.0009], p < 0.01), Purdue Pegboard (dominant∃=!0.0159 [SE0.0042], p < 0.01; non-dominant∃= 0.0169 [SE 0.0042], p < 0.01;both∃=!0.0142 [SE 0.0038], p < 0.01; assembly∃=!0.0493 [SE0.0151], p < 0.01), and Pursuit Aiming (# correct∃=!0.1629 [SE0.0473], p < 0.01; # incorrect∃=!0.0046 [SE 0.0023], p < 0.05). Themagnitude of the effect for these eight tests significantly associatedwith blood Pb was an increase in blood Pb of 5 μg/dL was equivalentto an increase of 1.05 yrs in age. Use of Lowess lines for PurduePegboard (assembly) and Trails B suggested a threshold at blood Pb18 μg/dL after which there is a decline of performance.

# AX6-45Table AX6-3.3 (cont’d). Neurobehavioral Effects Associated with Occupational Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationAsia(cont’d)Schwartz et al. (2005)South Korea1997-2001Longitudinal decline in neurobehavioralperformance examinedin 576 of the abovegroup of Pb exposed workers who completed3 visits at one yr intervals.Mean age at baseline was 41 (9.5) yrs andjob duration 9 (6.3) yrs and 76% were men.Compared to non-completers Pb workerswho completed 3 visits were 3.3 yrs older,baseline mean blood Pb was 2.0μg/dL lower,on the job 1.6 yrs longer, 24% women vs.10% of noncompleters, and usually had lessthan high school education. Modelsexamined short-term vs. long-term effects.Final model had current blood Pb, tibia bonePb and longitudinal blood Pb and covariates.Baseline mean (SD) bloodPb 31 (14.2) μg/dLMean (SD) tibiaPb 38 (43) μg/gBlood Pb from baseline correlated with those from visit 2 and 3 andbaseline tibial Pb correlated with that measured at visit 2. Cross-sectional associations of blood Pb orshort-term change occurred withTrails A (∃=!0.0020 [95% CI:!0.0040,!0.0001]) and B(∃=!0.0037 [95% CI:!0.0057,!0.0017]), Digit Symbol (∃=!0.0697[95% CI:!0.1375,!0.0019]) , Purdue Pegboard(dominant∃=!0.0131 [95% CI:!0.0231,!0.0031]; non-dominant∃=!0.0161 (95% CI:!0.0267,!0.0055); both (∃=!0.0163, [95% CI:!0.0259,!0.0067]; assembly (∃=!0.0536 [95% CI:!0.0897,!0.0175]), and Pursuit Aiming (# correct∃= 0.1526, [95% CI:!0.2631,!0.0421]) after covariates. However, longitudinal blood Pbwas only associated with poorerperformance on Purdue Pegboard(non-dominant∃=!0.0086 [95% CI:!0.0157,!0.0015]; both(∃=!0.0063 [95% CI:!0.0122, 0.0004]; assembly (∃=!0.0289 [95%CI:!0.0532,!0.0046]). Historical tibial bone Pb was associated withdigit symbol (∃=!0.0067 [95% CI:!0.0120, 0.0014]) and PurduePegboard (dominant∃=!0.0012, [95% CI:!0.0024,!0.0001]).Magnitude of Pb associations wasexpressed as the number of yrs ofincreased age at baseline that was equivalent to an increase of Pb fromthe 25th to 75th percentile. At baseline, these Pb associations wereequivalent to 3.8 yrs of age for cross-sectional blood Pb, 0.9 yrs ofage for historical tibial Pb and 4.8 yrs of age for longitudinal bloodPb. Analyses showed decline in performance over time related totibia Pb.

# AX6-46Table AX6-3.3 (cont’d). Neurobehavioral Effects Associated with Occupational Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationAsia(cont’d)Hwang et al. (2002)South KoreaFrom the above cohort of 803 Korean Pbworkers, 212 consecutively enrolled workers,were examined for protein kinase C (PKC)activity and the relations between blood Pband neurobehavioral performance. PKCactivity assessed by measuring levels ofphosphorylation of three erythrocytemembrane proteins. Seventy-four percent ofworkers were men, mean age 36(0.8)yrs,duration of exposure 9 (0.6) and education93% had high school or less. For the femaleworkers, mean age 47 (0.9) yrs, duration ofexposure 6 (0.5), and education 95% hadhigh school or less.Male workersMean (SD) blood Pb 32(13.0) μg/dLMean (SD) tibia Pb 38(39.6) μg/gMean (SD) ZPP 69(47.8) μg/dLFemale workersMean (SD) blood Pb 20(9.2) μg/dLMean (SD) tibia Pb 26(14.7) μg/gMean (SD) ZPP 72(29.7) μg/dLBlood Pb was associated significantlywith decrements in Trails B(∃=!0.003 [SE 0.002], p < 0.10), SRT (∃=!0.0005 [SE 0.0003],p < 0.10) and Purdue Pegboard (dominant∃=!0.21 [SE 0.010],p < 0.05); non-dominant (∃=!0.021 [SE 0.010], p < 0.05); both(∃=!0.021 [SE 0.009], p < 0.05). PKCactivity as measured by backphosphorylation of erythrocyte membrane proteins was not associatedwith neurobehavioral test scores. Addition of the interaction term ofblood Pb by back-phosphorylation dichotomized at the median foundsignificant effect modification with the association of higher blood Pband poorer neurobehavioral performance occurring only amongworkers with lower back-phosphorylation levels that corresponds tohigher in vivo PKC activity. Association of blood Pb and SRT for the52 kDa subunit with high invivo PKC activity (adjusted∃=!0.001,p < 0.01) and for low in vivo PKC (adjusted∃=!0.0001, p = 0.92).The authors suggest that PKC activity may identifya subpopulation atincrease risk of neurobehavioral effects of Pb.Chuang et al. (2005)Taiwan27 workers from a glazing factory wereadministered a computerizedneurobehavioral battery 3 times over 4 yrs.At yr 1, the mean age was 40 (9.6) yrs. Inthe first yr workers were compared to areferent group matched for age andeducation. Neurobehavioral performancecompared in first yr to referent group withadjustment for age and Vocabulary.Generalized mixed linear mixed modelsanalyzed relationship between blood Pb leveland neurobehavioral test performance afteradjusting for age and Vocabulary.Pb workersYr 1Mean (SD) blood Pb 26(12)Yr 3Mean (SD) blood Pb 11(6.4)Yr 4Mean (SD) blood Pb 8 (6.9)ReferentMean (SD) blood Pb 7 (4.2)Referents scored significantly lower on questionnaire for chronicsymptoms in yr 1. In the mixed model analyses finger tappingdominant (p = 0.008) and non-dominant (p = 0.025) weresignificantly inversely associatedwith blood Pb. Pattern comparison(p < 0.001) and Pattern memory (p = 0.06) improved significantly asblood Pb levels improved. Chronic symptoms and neurobehavioralperformance appear to reverse when Pb exposure is decreased.However since the referent group was not tested in yr 3 and yr 4 itwas not possible to control for practice effect known to occur withrepeat neurobehavioral testingeven at two yr intervals.

# AX6-47Table AX6-3.3 (cont’d). Neurobehavioral Effects Associated with Occupational Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationAsia(cont’d)Tsai et al. (2000)Taiwan19 Pb workers and 19 referents included inthe above publication, mean age 39 yrs inboth groups and mean education 10 (2.9) and9 (3.2) yrs, respectively, were tested with acomputerized neurobehavioral battery.Alcohol use was similar. Mean duration ofPb exposure 6 (2.5) yrs. Student’s tcompared neurobehavioral performancebetween the two groups.Mean (SD) blood Pb 32(12.2) μg/dLReferentMean (SD) blood Pb 7(2.7) μg/dLPoorer performance in Pb workersfor finger tapping, dominant andnon-dominant, and continuous performance task but only fingertapping was significant. Pb workers performed better than referentson Associate Learning, Pattern Comparison Test, Pattern MemoryTest, Visual Delay and Associate Learning Delayed that wasattributed to higher mean education.Chia et al. (2004)Singapore120 workers from Pb stabilizer factories,mean age 40 (10.7) yrs, duration of exposure10.2 (7.9) were given a neurobehavioralbattery. Genotyping of ALADpolymorphisms was performed. ANCOVAused to test for differences inneurobehavioral performance among ALADpolymorphism types adjusting for age,exposure duration and blood Pb.Mean (SD) blood Pb 22(9.4) μg/dLMean (SD) ALAD0.6(0.25) μm ofporphobilinogen/h/ml ofRBCMean (SD) ALAU0.9(0.56) mg/g creatinineFrequency of ALAD11, 87%, ALAD12, 12%, and ALAD22, 1%.Mean blood Pb adjusting for age and exposure duration was 20 μg/dLfor ALAD11 (n = 107) and 20.4 μg/dL for ALAD12 and 22 (n = 13).However ALAU was significantly higher in ALAD11 (p = 0.023).After adjusting for the covariates significant differences for groovedpegboard dominant hand (p = 0.01), non-dominant hand (p = 0.04),and grooved pegboard mean time (p = 0.006) were found betweenALAD11 and ALAD12 and 22. Considering cognitive tests were partof battery it is surprising education was ignored. As noted by theauthors the study only had 13 in the group with better performanceand the ALAD12 or 22 genotypes limiting the power.Chia et al. (1997)Singapore50 Pb battery manufacturing workers, meanage 36 (10.6) yrs, education 8.6 (2.1) yrsduration of employment 9 (7.4) yrs and97 controls, mean age 34 (3.7) yrs, andeducation 12 (1.8) yrs were administered aneurobehavioral battery. ANCOVA andlinear regression used to assess relationshipof Pb dose and performance.Pb workersMedian (range) blood Pb of38 (13.2-64.6) μg/dLMedian (range) IBL 264(10.0-1146.2) μg·yr/dLControlsMedian (range) blood Pb 6(2.4-12.4) μg/dLSignificant group differences for Santa Ana, grooved pegboard, digitsymbol, pursuit aiming and Trails A and B after adjusting for age,education, smoking, ethnic group andalcohol use. When the exposedgroup was stratified by age, in the group >35 yrs the poorerperformance on digit symbol and Trails A was significantlyassociated with cumulative Pb and not blood Pb after adjustingfor age and education.

# AX6-48Table AX6-3.3 (cont’d). Neurobehavioral Effects Associated with Occupational Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationAsia(cont’d)Niu et al. (2000)China44 Pb-exposed workers (17 men, 27 women)from Pb printing houses, mean age 35 (4.9)and education 9.3 (no SD) yrs and 34controls (19 men and 15 women), mean age33 (7.4) yrs and education 9.5 (no SD) yrscompleted the NCTB. ANCOVA controllingfor age, sex and education examined groupdifferences and linear regression for dose-response relationship.Pb workersMean (SD) blood Pb 29(26.5) μg/dL(8 workers blood Pbexceeded 50 μg/dL)ControlsMean (SD) blood Pb 13(9.9) μg/dL(1 control blood Pbexceeded 50 μg/dL)SRT (F = 2.30, p < 0.05), digit symbol (F = 4.81, p < 0.01) pursuitaiming # correct (F = 7.186, p < 0.01) and pursuit aiming total(F = 6.576, p < 0.01) had significantly poorer performance comparedto controls. No repression analyses provided.Boey and Jeyaratnam(1988)Singapore49 Pb-exposed workers, mean age 26 (7.6)yrs and 36 controls, mean age 30 (6.4) yrscompleted SRT and 8 psychological testscovering attention, vigilance, visual-motorspeed, short-term memory, visuomotortracking, visual scanning, and manualdexterity. Control group was matched foreducation level. Discriminate analysis ofneurobehavioral tests performed to determinewhich best discriminate the groups.Pb workersMean (SD) blood Pb 49(15) μg/dLControlsMean (SD) blood Pb 15(3) μg/dLSix tests were significantly different between the two groups-DigitSymbol, Bourdon-Wiersma, TrailsA, Santa Ana dominant, FlickerFusion and SRT. The group of tests that best differentiates Pbexposed workers from nonexposed workers were Simple ReactionTime, Digit Symbol (WAIS) and Trail Making Test (Part A) withlong latency in reaction time contributing three times more to thederived function than Digit Symbol (WAIS) or Trails A.

# AX6-49Table AX6-3.4. Meta-analyses of Neurobehavioral Effects with Occupational Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationBalbus-Kornfeld et al.(1995)Reviewed 21 studies from 28 publications;number of subjects ranged from 9-708.Mean blood Pb in mostexposed group28-68 μg/dL. Only 5studies used a measure ofcumulative exposure orabsorption of Pb, 2 studiesused duration of exposure.Dexterity (17/21 studies) and executive or psychomotor 11/21studies were the functional domains most commonly associated withPb. Age not adequately controlledin most studies, usually matchingmeans or medians. Intellectualabilities prior to exposure usuallyadjusted for with education; however, Vocabulary, a measure ofoverall intellectual ability stilldifferent between the groups.The conclusion reached that evidence of effects from cumulativeexposure or absorption of Pb was inadequate.Davis and Svendsgaard(1990)Meta-analysis of 32 studies of nerveconduction studies and Pb exposure.Presented 41 effect sizes with the overall effect size for all studiesD =!0.369 (p#0.001). All median nerves combined was D =!0.481(p#0.001) and for all ulnar nerves D =!0.211 (p#0.001). Themedian motor was most sensitive with an effect size of D =!0.553(p#0.001). Overall blood Pb was a weak measure of exposure forthe peripheral nervous system. Paradoxical association found effectsize smaller with increasing blood Pbbut increased with duration ofexposure.Meyer-Baron andSeeber (2000)Meta-analysis of studies with blood Pb<70 μg/dL found 12 studies with comparabletest procedure and sufficient documentationof results. Thirteen tests from the 12 studiesexamined.Exposed groupRange of mean blood Pb 31to 49 μg/dLControlsRange of mean blood Pb 6to 18 μg/dLBlock Design, Logical Memory,and Santa Ana had performancedeficits with small effect size. For Block Design the effect size wascomparable to changes observed with 20 yrs of aging. Aiming, SRT,Trials A and B, Digit Span and Digit Symbol also had poorerperformance but the large variance for effect sizes suggest otherfactors besides Pb exposure influenced performance. The authorsconclude, “that the evidence of neurobehavioral deficits at a blood Pbof ~40 μg/dL is obvious.”Goodman et al. (2002) Meta-analysis of 22 studies with medianblood Pb <70 μg/dL, numbers of exposedand unexposed workers given with scoresand dispersion on neurobehavioral tests.Exposed groupRange blood Pb 24 to63 μg/dLUnexposed groupRange blood Pb 0 to28 μg/dLDigit symbol and D-2 errors significant effect forfixed effects,weighted random effects and unweighted random effects. Simplereaction time, grooved pegboard, Trails A and B, picture completionvisual reproduction, eye-hand coordination and vocabulary hadsignificant effects for the fixed effects model only. The authorsconclude none of the individual studies were adequate or conclusiveof subclinical neurobehavioral effects of exposure to Pb as thebiological effects of blood Pb <70 μg/dL are inconsistent. (SeeSchwartz et al. (2002) for comments).

# AX6-50Table AX6-3.4 (cont’d). Meta-analyses of Neurobehavioral Effects with Occupational Lead Exposure in AdultsReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationSchwartz et al. (2002)Letter to the Editor commenting onshortcomings in the Goodman et al. (2002)meta-analysis on studies of neurobehavioraltesting in workers occupationally exposed toPb.The six points regarding problems with the methodology included:(1) no evaluation of quality of study design or statistical methods,(2) data from poorly done and well done studies are combined,(3) included 6 studies with no age adjustment and 3 with noadjustment for education, (4) confounding of age and educationwhen addressed the variation acrossstudies not discussed, (5) maineffect only examined exposed vs. nonexposed comparisons that areknown to have the lowest power, cannot evaluated dose-effectrelationships and have a tendency for selection bias, and (6) few ofthe 22 studies included contributed to effect size.Seeber et al. (2002) A comparison of the two meta-analysesMeyer-Baron and Goodman) performed toevaluate recommendations of a German BEIof 40 μg/dL.Effect size calculated for 12 testsin two meta-analyses and 10 testsfrom one meta-analyses found subtleimpairments associated withblood Pb between37 μg/dL and 52 μg/dL for Logical Memory,Visual Reproduction, Simple Reaction Time, Attention Test d2,Block Design, and Picture Completion, Santa Ana, GroovedPegboard and Eye-hand Coordination. Effect sizes related to agenorms between ~40 to 50 yrs. For example,!3 score on BlockDesign = 10 to 15 yrs;!3.5 score on Digit Symbol = 10 yrs;!21 scoreon Cancellation d2 = 10 yrs; and +5 to +6 on Trails A = 10 to 20 yrs.This analyses concluded thatboth meta-analyses supportedrecommendation for German BEI of 40 μg/dL.Graves et al. (1991) A meta-analysis on 11 case-control studies ofAlzheimer’s disease for occupationalexposure to solvents and Pb.Four studies had data for Pb exposure with a pooled analysis ofrelative risks for occupational Pb of 0.71 (95% CI: 0.36, 1.41).The exposure frequencies were 16/261 for the cases and 28/337 forthe controls.

# AX6-51Table AX6-3.5. Neurophysiological Function and OccupationalLead Exposure in AdultsReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationCanadaBleecker et al. (2005b)New Brunswick1992-199374 current smelter workers, mean age44 (8.4) yrs, education 8 (2.8) yrs andemployment duration 20 (5.3) yr had currentperception threshold (CPT) measured forlarge and small myelinated and unmyelinatednerve fibers in the finger. Linear regressionmodeled CPT on metrics of Pb dose afteradjusting for covariates. Interaction of Pbdose and ergonomic stressor on peripheralnerve function was assessed.Mean (SD) blood Pb 26(7.1) μg/dLMean (SD) IBL 891(298.8)μg·yr/dLMean (SD) TWA 42(8.4)μg/dLMean (SD) tibia bone 40(23.8) μg/g5 metrics relating to IBLcumulated only exposureabove increasing blood Pbranging from 20 to60 μg/dLBlood Pb and tibial bone Pb were not associated with any of the threenerve fiber populations. IBL and TWA accounted for a significantpercentage of the variance only for the large myelinated nerve fibers(♠R2= 3.9%,♠R2= 8.7% respectively). The relationship of CPT andTWA was curvilinear with a minimum at a TWA of 28 μg/dL.Unique variance of CPT for large myelinated fibers explained bydifferent thresholds of IBL were IBL – 3.9%, p = 0.08; IBL20 – 5.8%,p < 0.03, IBL30 – 7.8%, p < 0.02; IBL40, p < 0.005; IBL50,p < 0.005; and IBL60, p < 0.005. IBL60 also explained significantvariance of CPT for small myelinated nerve fibers demonstrating anincreased impairment in peripheralnerve function. This effect onmyelinated sensory nerve fibers was enhanced when a measure ofergonomic stress was added to the model for IBL60.EuropeKovala et al. (1997)Finland60 workers in a Pb battery factory with amean age of 43 (9) yrs and mean exposureduration of 16 (8) yrs. Nerve conductionstudies, vibration thresholds, and quantitativeEEG were performed. Relationship of Pbexposure with peripheral nerve function andquantitative EEG were examined by partialcorrelation and regression analyses adjustingfor age.Mean (SD) tibial Pb 26(17) mg/kgMean (SD) calcaneal Pb88 (54) mg/kgMean (SD) IBL 546(399)μg·yr/dLMean (SD) TWA 34(8.4) μg/dLMean (SD) maximumblood Pb 53 (19) μg/dL,Mean (SD) blood Pb 27(8.4) μg/dLThe sensory amplitude of the medianand sural nerves had a negativecorrelation with IBL and duration of exposure that was not related toage. Vibration threshold at the ankle related significantly to IBL andduration of exposure after adjusting for age. Vibration threshold inthe finger was associated with bloodPb and blood Pb avgs over thepast three yrs. The alpha and beta frequencies were more present inworkers with higher long term Pb exposure such as tibial andcalcaneal, IBL and TWA. Overall historical blood Pb measures weremore closely associated with peripheral nerve function than bone Pbconcentrations. The study had no comparison group and did notaccount for the effect of smoking and alcohol use or give their usagein this population.

# AX6-52Table AX6-3.5 (cont’d). Neurophysiological Functionand Occupational Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationAsiaSchwartz et al.(2001a)South Korea1997-1999804 workers from 26 different Pb usingfacilities and 135 controls with a mean age of40 ( 10.1) and 35 (9.1) yrs respectively, jobduration of 8 (6.5) and 9 (5.3) yrsrespectively, and education level 42 % and69% completed high school respectively hadcomparable alcohol and smoking use. Linearregression used to compare vibrationthreshold in Pb exposed and controlscontrolling for potential confounders.Pb-exposed workersMean (SD) blood Pb32 (15) μg/dLMean (SD) tibia bone Pb37 (40.3) μg/gMean (SD) DMSA-chelatable Pb186 (208.1) μg (4 hcollection)After adjustment for age, gender,education and height, tibia Pb butnot blood Pb was significantly associated with poorer vibrationthreshold in the dominant great toe but not the finger (∃=!0.0020[SE 0.0007], p < 0.01). These results contrast with those forneurobehavioral measures (see above) performed in the same studywhere tibial Pb was not a predictor of performance.Schwartz et al. (2005)South Korea1997-2001Longitudinal decline in neurobehavioralperformance examinedin 576 of the abovegroup of Pb exposed workers who completed3 visits at one yr intervals.Mean age at baseline was 41 (9.5) yrs andjob duration 9 (6.3) yrs and 76% were men.Compared to non-completers Pb workerswho completed 3 visits were 3.3 yrs older,baseline mean blood Pb was 2.0 μg/dLlower, on the job 1.6 yrs longer, 24% womenvs. 10% of noncompleters, and usually hadless than high school education. Modelsexamined short-term vs. long-term effects.Final model had current blood Pb, tibia bonePb and longitudinal blood Pb and covariates.Baseline mean (SD) bloodPb 31 (14.2) μg/dLMean (SD) tibia Pb 38(43) μg/gAfter adjustment for age, visit number, education, gender, height(for vibration) and BMI (for grip strength and pinch) vibrationthreshold in the dominant great toe and not the finger was associatedwith tibia Pb (∃=!0.0006 [95% CI:!0.0010,!0.0002]) andlongitudinal blood Pb (∃=!0.0051 [95% CI:!0.0078,!0.0024])in one model and blood Pb (∃=!0.0019 [95% CI:!0.0039, 0.0001])in another model.

# AX6-53Table AX6-3.5 (cont’d). Neurophysiological Functionand Occupational Lead Exposure in AdultsReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationAsia(cont’d)Chuang et al. (2000)Taiwan206 Pb battery workers, mean age 41 yrs,with annual blood Pb for the previous fiveyrs had vibration perception measured inhand and foot. Relationship of Pb exposureterm and vibration perception thresholdassessed with multiple regressions, hockeystick regression analysis after adjusting forpotential confounders.Mean blood Pb 28 μg/dLMean blood Pb over past5 yrs 32 μg/dLMean maximum blood Pb39 μg/dLMean index of cumulativeexposure 425 μg·yr/dLMean TWA 32 μg/dLMean working duration13 yrs and life span inwork 31%After adjustment for age, sex, body height, smoking, alcoholconsumption, and use of vibratinghand tools, significant associationbetween mean blood Pb and mean TWA and vibration perception inthe foot were found. After adjustment for the covariates, a hockeystick regression analysis of footvibration threshold vs. mean bloodPb concentration for 5 yrs found an inflection point around 30 μg/dLwith a positive linear relation above this point suggesting a potentialthreshold.Chia et al. (1996a)Singapore72 workers in a Pb battery manufacturingfactory with a mean age of 30 yrs andreference group of 82 workers had nerveconduction studies and blood Pb performedevery 6 mos over the course of three yrs.Only 28 Pb battery workers completed theprogram. At the end of the first yr of the 82workers in the comparison group only 26remained and by yr 3 this had decreased to 4.Mean nerve conduction values examined byANCOVA between the exposed andreference after adjustment for age, ethnicgroup, smoking and drinking habits.Analysis of serial nerve conduction valuesand blood Pb treated as a clustered samplehad the within-cluster regression coefficientexamined. The 28 exposed workers werestratified by blood Pb level and therelationship between nerve conduction valuesand blood tested within the cluster.Geometric mean blood Pbconcentrations for the 6testing periods: 37, 41, 42,40, 41, and 37 μg/dLOverall range for blood Pb16-73 μg/dLThe relationship between blood Pb levels and nerve conductionvalues for the 28 exposed workers was significantfor all outcomesexcept median motor conduction velocity and ulnar sensory nerveconduction velocity and ulnar sensory amplitude. The regressioncorrelation coefficients for blood Pb >40 μg/dL was significant forall parameters exceptthe median sensory conduction velocity andfor blood Pb <40 μg/dL there was no association with nerveconduction values. Therefore the blood Pb level associated withno change in nerve conduction studies was <40 μg/dL.

# AX6-54Table AX6-3.5 (cont’d). Neurophysiological Function and Occupational Lead Exposure in AdultsReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationAsia(cont’d)Chia et al. (1996b)SingaporeExtension of above study - 72 workers in Pbbattery manufacturing and 82 controls. Meanduration of exposure 5.3 yrs.Mean blood Pb 37 μg/dLMean cumulative blood Pb137 μg·yr/dLANCOVA found significant differences for all nerve conductionparameters except three for the ulnar nerve, after adjusting for age,ethnic groups, smoking and drinking habits. There was nosignificant correlation between blood Pb and cumulative blood Pbwith nerve conduction values afterlinear regression with adjustmentfor confounders. When cumulative blood Pb was stratified- 12workers <40 μg·yr/dL, 28 workers 40-300 μg·yr/dL, 21 workers>300 μg·yr/dL ANCOVA found significant differences for5 nerve conduction parameters. The strongest dose effectrelationship was for sensorynerve conduction velocity.Chuang et al. (2004)Taiwan181 Pb battery manufacture workers werestratified by milk drinkers, n = 158 and non-or rare mild drinkers n = 23. Mean age in thetwo groups was 40 and 36 yrs and workingduration 10/8 yrs respectively. Peripheralnerve evaluation was with current perceptionthreshold at 3 frequencies 5Hz = C fibers,250 Hz = A-delta fibers and 2000 Hz = Abeta fibers. Linear regression estimated theassociation of CPT and Pb exposure variableand adjustment of milk intake and potentialconfounders.Blood PbMilk drinkers 25 μg/dLNon or rare milk drinkers30 μg/dLTWAMilk drinkers 28 μg/dLNon or rare milk drinkers32 μg/dLIBLMilk drinkers 316 μg·yr/dLNon or rare mild drinkers245 μg·yr/dLAge was significantly different butdistributions of gender, smoking,alcohol use, use of hand vibrationtool, working history and heightwere not different. Linear regressions found association of 5 Hz CPTand 250 Hz CPT in hand and foot with blood Pb and TWA but notIBL. However the protective effects of drinking milk was present forall fiber populations only in the hands. This paper presents anunusual finding of subclinical Pb neuropathy involving theunmyelinated and small myelinated fibers. Toxic axonopathiesclassically involve the large nervefibers. The main group differencemay be related to other nutritional deficiencies associated with themalabsorption syndrome that lead to the non-milk drinking status.Yokoyama et al.(1998)Japan17 gun-metal workers, mean age 48 yrs and a20 controls with a mean age of 45 yrs haddistribution of conduction velocities (DCV)measured and the maximum median sensoryconduction velocity (SVC) performed twiceat a yr interval. Group differencescontrolling for confounders and dose-effectrelationships were examined.Mean blood Pb 40 μg/dLMean mobilized Pb(CaEDTA) in urine1 mg/24 hANCOVA controlling for age and alcohol found mobilized Pb wasassociated with significant slowing in the large nerve fibers whileblood Pb was not. Workers with increased change in mobilized Pbover 1 yr interval (mean 0.44 mg/24hr) had significant reduction inlarge fiber (V95) conduction velocity while those workers with lesschange in mobilized Pb (0.08mg/24hr) did not have significantchange in DCV or SVC. It appears that larger faster conductingnerve fibers are susceptible to Pb and a measure of body burden(readily mobilized Pb from soft tissue) is a stronger predictor of thischange than blood Pb.

# AX6-55Table AX6-3.5 (cont’d). Neurophysiological Function and Occupational Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationAsia(cont’d)He et al. (1988)China40 workers in a Pb smelter with age range 20to 45 yrs (no mean provided) and duration ofexposure 5.4 yrs. Fifty controls age 20 to55 yrs. Nerve conduction studies examined11 parameters.Student = s t-test examinedfor differences between exposed andcontrols.Mean blood Pb 40 μg/dLMean urinary Pb 71 μg/dLMean ALAU5 μg/dLThere were no symptoms or signs of peripheral nerve disorder.Both motor and sensory conduction velocities were slowed in the Pbexposed groups. 10 nerve conductionparameters were significant inthe group with blood Pb >40 μg/dL and 6 parameters weresignificant in the group with blood Pb <40 μg/dL. An unusualfinding in this study was the lackof age association with nerveconduction values and therefore it was not controlled for in theanalyses.Niu et al. (2000)China44 Pb-exposed workers (17 men, 27 women)from Pb printing houses, mean age 35 (4.9)and education 9.3 (no SD)yrs and 34 controls(19 men and 15 women), mean age 33 (7.4)yrs and education 9.5 (no SD) yrs had nerveconduction studies formaximal motor nerveconduction velocity.ANCOVA controllingfor age, sex and education examined groupdifferences and linear regression for doseresponse relationship.Pb workersMean blood Pb 29(26.5) μg/dL(8 workers blood Pbexceeded 50 μg/dL)ControlsMean blood Pb 13(9.9) μg/dL(1 control blood Pbexceeded 50 μg/dL)Only 12 Pb exposed workers and 24 controls examined for NCV.Left ulnar nerve was significantlyslower but the left median andright ulnar were faster in the Pbexposed and the right median wasslightly slower. This appears to be a finding of chance due to thesmall n. For the Pb exposed group mean left ulnar CV was 52 whilethe mean right ulnar CV was 59 while for the controls left ulnar CVwas 58 while the mean right ulnar CV was 55.

# AX6-56Table AX6-3.6. Evoked Potentials and Occupational Lead Exposure in AdultsReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationCanadaBleecker et al. (2003)New Brunswick1992-1993359 currently employed smelter workers, mean age 41yrs, had brainstem auditory evoked potentials (BAEP)measured. Relationship between absolute latenciesand interpeak latencies assessed using linear regressionafter adjusting for potential confounders. Exposurewas assessed in cases withclinical abnormalities inWave I and I-V interpeak latency compared to thoseworkers with normal BAEPusing post-hoc analysis.Mean blood Pb 28 μg/dLMean TWA 39 μg/dLMean IBL 719 μg·yr/dLLinear regression after the contribution of age found bloodPb and TWA were significantly associated with Wave Iwhile IBL was significantly associated with Wave III and I-III interpeak interval. Fourgroups created with increasingabnormalities based upon clinical cut-off scores for Wave Iand I-V interpeak interval hadsimilar age. blood Pb, TWAand IBL were all significantly higher in the group withprolonged Wave I and I-V interpeak interval comparedto the group with normal BAEP = s. These findingssupport involvement of the brainstem and auditory nervewith Pb exposure.EuropeAbbate et al. (1995)Italy300 Pb exposed men ages 30 to 40 yrs in good healthwith no other neurotoxic exposure had P100 latencymeasured for visual evoked potentials (VEP) for 15and 30 minute of arc. Groups created based uponblood Pb had VEPS examined followed by linearregression for each group.Blood Pb 17 to 60 μg/dLrangeMean blood Pb for 4 groupsn = 39 23 μg/dLn = 113 30 μg/dLn = 89 47 μg/dLn = 59 56 μg/dLANOVA of the blood Pb and P100 latencies weresignificantly prolonged for 15 and 30 minutes of arc.Linear regression found the association of blood Pb andP100 were significant in each group but the relationshipwas not proportional (angular coefficient). Effect of bloodPb on VEP began at 17-20 μg/dL.With age limited to onedecade, contribution from age was not a concern. Eventhough no comparison group, careful screening ruled outother medical and eye conditions and other potentialexposures.Discalzi et al. (1992)Italy49 Pb exposed workers and 49 age and sex matchedcontrols had BAEPs measured. Relationship of 6BAEP outcome variables and Pb exposure examinedwith analysis of variance and linear regression.Mean blood Pb 55 μg/dLMean TWA for previous3 yrs 54 μg/dLLatencies for waves I, III, V and interpeak latencies, I-V, IIII, and III-V were all significantly prolonged in the Pbexposed workers (p < 0.04).No significant associationfound with linear regression between BAEP outcomes andexposure variables. In those workers with TWA>50 μg/dL, I-V latency was significantly prolongedcompared to workers with TWA <50 μg/dL.

# AX6-57Table AX6-3.6 (cont’d). Evoked Potentialsand Occupational Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationEurope(cont’d)Discalzi et al. (1993)Italy22 battery storage workers, mean age 35 yrs and 22control group, age and sex matched, with normalhearing had BAEPs recorded. Latencies I and V and Pbexposure examined by ANOVA after stratifying bloodPb.Mean blood Pb 48μg/dL Interpeak latency I-V was significantly prolonged in Pbexposed workers (p = 0.001). No significant associations bylinear regression between I-V and Pb exposure. StratifyingPb exposed workers by blood Pb 50 μg/dL found I-Vinterpeak latency significantly prolonged (p = 0.03) insubgroup with higher blood Pb.Latin AmericaCounter and Buchanan(2002)Ecuador30 Pb-glazing workers, median age 35 yrs, had pure-tone thresholds and BAEPs performed. Regressionanalyses examined relations between auditory outcomesand blood Pb.Mean blood Pb 45 μg/dL(range 11 to 80 μg/dL)Sixty percent of the men and 20 percent of the women hadabnormal high-frequency thresholds, however there was nosignificant relationship with blood Pb and pure tone thresholdat all frequencies. Analysis of BAEPs found agreementbetween latencies for WavesI, III and V and peripheralhearing status. Interpeak latencies were within normal limitsbut no analysis provided with Pb exposure. Workers lived ina Pb contaminated environment from discarded Pb-acidstorage batteries. Therefore a measure of chronic Pbexposure may have been more appropriate.AsiaHoldstein et al. (1986)Israel20 adults and 8 children (mean age 27 yrs, range 8 - 56yrs) accidentally exposed to Pb through food until one yrprior to measurement of BAEP.Mean blood PbAdult 31 μg/dLChildren 22 μg/dL10 mo avg blood Pb Adults43 μg/dLChildren 36 μg/dLIn adults, latencies I, III andI-III and I-V interpeak intervalswere significantly longer than the control group (p < 0.05).When group stratified by 10 mo avg blood Pb I-III interpeakinterval was longer in the high group. Age and blood Pbwere not studied due to fewsubjects. The I-III interpeakinterval reflects transmission in the lower brainstem andVIIIth nerve.

# AX6-58Table AX6-3.6 (cont’d). Evoked Potentialsand Occupational Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationAsia(cont’d)Hirata and Kosaka(1993)Japan41 Pb-exposed men from Pb-glass-based colors manufacturing(n = 20), production of Pb electrode plates (n = 8), casting of Pb-bronze (n = 4) and casting of Pb pipes and plates (n = 9) had meanage 41 yrs, mean duration of exposure 13 yrs. A battery of testsadministered including radial nerve conduction study,electroretinogram (ERG), visual evoked potential (VEP),brainstem auditory evoked potential (BAER), and short-latencysomatosensory evoked potential (SSEP). Comparison group of 39unexposed used only for BAER analysis by Student’s t test.Correlation and linear regression controlling for age examined therelationship of Pb and the other variables.Mean (range) blood Pb43 μg/dL (13-70)Mean (range) TWA (basedupon previous 5 yrs)43 μg/dL (13-70)Mean (range) duration ofexposure 13 (0.6-29) yrsSignificant partial correlation after adjusting for ageincluded TWA and radial motor conduction velocity,blood Pb and sensory conduction velocity, exposureduration and VEP, blood Pb and SSEP-N20.Comparison of BAERs of 15 Pb exposed and 39controls found interpeak interval III-V wasprolonged significantly. It is not clear whycomparison group only used for BAERs.Considering the large number of variables examinedwith three exposure terms some of the findings couldbe by chance alone.Murata et al. (1993)Japan22 gunmetal foundry workers with age range of 32 to 59 yrs andwork duration of 1 to 19 yrs and control group matched for age,no chronic disease and no Pbexposure participated. Nosignificant difference betweengroups for age, height, skintemperature, alcohol consumption,and yrs of schooling. The testbattery consisted of visual evoked potential (VEP), brainstemauditory evoked potential (BAEP), short latency somatosensoryevoked potential (SSEP), event related potential (P300) and EKGR-R interval variability. Paired-sample t test examined fordifferences between the matched groups. Dose-effectrelationships examined with partial correlation adjusting for ageand stepwise linear regression.Blood Pb 12 to 64 μg/dL(no mean provided)For VEPs, N75 and N145 were significantlyprolonged in the Pb exposed workers. N9-N13interpeak latency of the SSEP was significantlyprolonged. BAEP latencies showed no significantdifferences. P300 believed to reflect cognitivefunction was prolonged in the Pb workers andcorrelated with blood Pb, and PbU. Autonomicnervous system effects weresignificantly diminishedfor CVR-Rand for a measure of parasympatheticactivity C-CVRSA. Fifty percent of the outcomevariables showed significant group differences butthere is limited dose effect for any outcome withinthe exposed group. Small sample size limitedconclusions with 20 outcome variables and 8biomarkers of Pb exposure.

# AX6-59Table AX6-3.7. Postural Stability, Autonomic Testing, Electroencephalogram, Hearing Thresholds, andOccupational Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited StatesDick et al. (1999)U.S.145 workers from a secondary Pb smelter, meanage 33 (8.7) and duration of employment 5 (4.8)yrs and 84 comparison workers mean age 30 (9.3)and duration of employment 4 (4.3) yrs hadpostural sway testing performed. The analysis ofexposure with test conditions and covariates usedmixed models.Pb workersMean (SD) blood Pb 39(8.5) μg/dLMean (SD) ZPP 55 (42.2) μg/dLMean (SD) CBL 230(217.9) μg·yr/dLMean (SD) TWA 35 9(8.5) μg/dLComparison workersMean (SD) blood Pb 2(1.7) μg/dLThe postural sway test had 6 conditions that varied thechallenge to the vestibular and proprioceptive afferents andvisual system. Only blood Pb had a significant effectprimarily on the one leg condition after the effects of thecovariates age, height, mass, and race. For the left leg,exposure slope estimate for area (b = 0.0067, t = 3.88,p = 0.0001) and length (b = 0.0046, t = 4.11, p = 0.0001)were significant. For the right leg only the exposure slopeestimate for length (b = 0.0033, t = 3.02, p = 0.0029) wassignificant. Dose effect was only significant when Pbworkers were combined with comparison workers. Ifcomparison workers with blood Pb level below 12 μg/dLremoved no significant exposure effect was found.EuropeKovala et al. (1997)Finland60 workers in a Pb battery factory with a meanage of 43 (9) yrs and mean exposure duration of16 (8) yrs. Quantitative EEG were performed.Relationship of Pb exposure with quantitativeEEG were examined by partial correlation andregression analyses adjusting for age.Mean (SD) tibial Pb 26(17) mg/kgMean (SD) calcaneal Pb88 (54) mg/kgMean (SD) IBL 546(399)μg·yr/dL,Mean (SD) TWA 34 (8.4) μg/dL,Mean (SD) maximum blood Pb53 (19) μg/dLMean (SD) blood Pb 27(8.4) μg/dLThe alpha and/or beta frequencies were more present inworkers with higher long term Pb exposure such as tibial(p < 0.05) and calcaneal (p < 0.05), IBL (p < 0.01) andTWA (p < 0.05). Slow alpha in workers was believed tocorrelate with increased episodes of ‘microdrowsiness’.The study had no comparison group and did not account forthe effect of smoking and alcoholuse or give their usage inthis population.

# AX6-60Table AX6-3.7 (cont’d). Postural Stability, Autonomic Testing, Electroencephalogram, Hearing Thresholds, andOccupational Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationAsiaIwata et al. (2005)Japan121 workers from a battery recycling plantand 60 age matched comparison group, meanage 46 (11) yrs. Height, body weight, bodymass index, and alcohol use was similar inboth groups. Pb group had significantlymore smokers. ANCOVA used to evaluatepostural sway after controlling for age,height, and smoking and drinking status.Benchmark dose level was calculated as the95% lower confidence limit of thebenchmark dose.Mean (SD) blood Pb 40(15) μg/dLReferentNot doneExcept for sagittal sway, all postural sway parameters with eyes openwere significantly larger in Pb workers. Blood Pb level in workerswas significantly associated with tosagittal sway at 1-2 Hz and 2-4Hz with eyes open, and sagittal and transversal sways at 1-2 Hz and2-4 Hz with eyes closed. The mean benchmark dose level of currentblood Pb level for postural sway was 14.3 μg/dL for the linear modeland 14.6 μg/dL for the K power model.Yokoyama et al.(1997)Japan49 chemical workers exposed to Pb stearate,mean age 48 (1.3) yrs and 23 controls, meanage 47 (2.5) had postural sway evaluated.ANCOVA examined group differences afteradjusting for covariates.Mean (SD) blood Pb 18(1.0) μg/dLMean (SD) maximumblood Pb 48 (3.8) μg/dLMean (SD) TWA 24(1.3) μg/dLMean (SD) Cumulativeblood Pb 391(48.2) μg·yr/dLThere were significant increases in sway in all directions at high andlow frequencies with eyes open and eyes closed (p < 0.05).Regression analysis found blood Pb associated with sway in theanterior-posterior direction, 0.5-1Hz (0.321, p = 0.03), 1-2Hz (0.313,p = 0.04) and TWA associated with right to left sway (0.326,p = 0.02) after adjustment for the covariates age, height, weight andalcohol consumption. The authors conclude that change in thevestibulo-cerebellum is affected by blood Pb while in the anteriorcerebellar lobe is affected by past Pb exposure.Chia et al. (1994a)Singapore60 Pb storage workers, mean age 32 (7.7) yrsand 60 controls, mean age 35 (7.4) hadpostural sway parameters measured.ANCOVA used to examine group differencesafter adjusting for covariates. Linearregression examined relationship between Pbexposure and postural sway.Pb workersMean (SD) blood Pb 36(11.7) μg/dLControlsMean (SD) blood Pb 6(2.4) μg/dLComputerized postural sway measurements found Pb workershave poorer postural stability thatincreased with eyes closed(p < 0.01). Regression analysisadjusting for age, height, andweight found no significantassociation with blood Pb.Chia et al. (1996c)SingaporeThe same 60 Pb storage workers as aboveand 60 control had postural sway dataexamined for contribution of cumulativeblood Pb fractionated over 10 yrs ofexposure.Pb workersMean (SD) blood Pb 36(11.7) μg/dLControlsMean (SD) blood Pb 6(2.4) μg/dLThe Pb exposed group had significantly poorer performance on allpostural sway parameters with eyesclosed compared to controls afteradjusting for height, weight, age and drinking habits (p < 0.01).All postural sway parameters witheyes closed were significantlyassociated with IBL for the 2 yrs prior to testing (n = 23, p < 0.05).

# AX6-61Table AX6-3.7 (cont’d). Postural Stability, Autonomic Testing, Electroencephalogram, Hearing Thresholds, andOccupational Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationAsia(cont’d)Ratzon et al. (2000)Israel63 Pb battery workers, mean age 39 (8.7) yrsand 48 controls mean age 36 (11.8) yrs,matched for age with similar sex andeducation, had postural control measured.Group differences examined with t test.Dose-effect relations assessed withPearson = s correlation coefficients. Linearregression done with exposure category asmajor predictor.Mean past blood Pb38 μg/dLMean yrs employed 11Cumulative Pb determinedby avg blood PbΗyrsemployedUsing a computerized sway measurement system the exposedworkers had significantly increased mean body oscillations with eyesclosed (p < 0.01) and head tilted forward (p < 0.001). Partialcorrelation adjusting for education, coffee consumption, hrs of sleepand estimate of health was significant only for total Pb exposure andincreased body oscillations with head tilted forward (∃= 2.25,p = 0.0089). In order to maintain balance Pb exposed workersrequired increased oscillations whenvisual and vestibular inputswere altered.Teruya et al. (1991)Japan172 Pb exposed workers, mean age 34(18.4-57.4) yrs had cardiac autonomicnervous system evaluated by R-R intervalsvariation with respiration measured.Mean (range) blood Pb 36(5-76) μg/dLAge adjustment controlled for byuse of ratios of predicted toobserved values. A significant doserelated decrease of R-R intervalvariation during deep breathing was present in 132 workers withstable blood Pb over the past yr (p < 0.01). This finding was moreprominent in younger workers with blood Pb∃30 μg/dL but a milddecrease present at blood Pb∃20 μg/dL. A decrease in R-R intervalvariation indicates decreased cardiac parasympathetic function.Ishida et al. (1996)Japan128 workers in the ceramic painting industry,58 men, mean age 55 (11.7) yrs and70 women, mean age 52 (9.2) yrs hadmeasures of sympathetic function byvariations in R-R interval on EKG andchanges in finger blood flow with posturalchanges using Doppler flowmetry.Correlation analyses and linear regressionexamined relationship of finger blood flowand Pb exposure after adjusting forcovariates.MenMean (SD) blood Pb 17(2.1) μg/dLMean (SD) ALAD% 61.6(28.3)%WomenMean (SD) blood Pb 11(1.7) μg/dLMean (SD) ALAD% 72.6(20.8)%22% had blood Pb >20 μg/dL, and 43% had ALAD% <60%. The46 workers in the lowest group with blood Pb <10 μg/dL hadALAD% >80% equivalent tononoccupational exposure andtherefore served as the control group. Blood Pb (∃= 0.205,p = 0.02), smoking (∃=−0.464, p < 0.01), and BMI (∃= 0.213,p = 0.01) were significant predictors of change in finger blood flowwith postural change. Decrease inchange of finger blood flow iscompatible with a peripheral sympathetic nerve impairment.

# AX6-62Table AX6-3.7 (cont’d). Postural Stability, Autonomic Testing, Electroencephalogram, Hearing Thresholds, andOccupational Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationAsia(cont’d)Niu et al. (2000)China44 Pb-exposed workers (17 men, 27 women)from Pb printing houses, mean age 35 (4.9)and education 9.3 (no SD) yrs and 34controls (19 men and 15 women), mean age33 (7.4) yrs and education 9.5 (no SD) yrshad autonomic nervoussystem examined.ANCOVA controlling for age, sex andeducation examined group differences andlinear regression for dose-responserelationship.Pb workersMean (SD) blood Pb 29(26.5) μg/dL(8 workers blood Pbexceeded 50 μg/dL)ControlsMean (SD) blood Pb 13(9.9) μg/dL(1 control blood Pbexceeded 50 μg/dL)Niu et al. (2000) examined autonomic nervous system in 44 Pbexposed workers, mean blood Pb29 μg/dL, and 34 controls, meanblood Pb, 13 μg/dL. Linear regression found association betweenblood Pb and decreased R-R interval with valsalva (F/T 2.349,p < 0.05) and duration of Pb exposure and decreased R-R intervalwith deep breathing (F/T 3.263, p < 0.01) after adjusting for age, sex,education, smoking and drinking.In the same study, quantitativeEEG found significant abnormalities in the Pb-exposed workers,dominant low amplitude in 59%, dominant beta frequency in 42%and abnormalities in 81%.

# AX6-63Table AX6-3.8. Occupational Exposure to Organolead and Inorganic Lead in AdultsReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationUnited StatesSchwartz et al. (1993)U.S.Two hundred and twenty-two currentemployees that manufactured tetraethyl Pbparticipated in a study to determine if therewas impairment on a neurobehavioral batteryassociated with a measure of cumulativeexposure to organic and inorganic Pb derivedfrom 12 yrs of air sampling. Mean age was44 (8.7) yrs, education 13 (1.7) yrs.Mean (SD) cumulative Pbexposure (inorganic andorganic) 869 (769) μg·yr/m3Mean (SD) yrs of exposure13 (9.5)Exposure was divided into 4 groups with the lowest for yrs ofexposure and cumulative Pb exposure serving as the reference group.After adjustments for premorbid intellectual ability, age, race, andalcohol consumption, cumulative Pb exposure had differentialassociation poorer performance in many cognitive domains but mostoften in manual dexterity and verbal memory/learning. Performanceon tests associated with exposure was 5 to 22% lower in the highestgroups when compared with the low exposure reference group.Stewart et al. (1999)U.S.543 former organolead workers, mean yrssince last exposure18, examined for ongoingneurobehavioral impairment related to pastPb exposure. Thirty-eight % were age 60 orolder, predominantly white, 93% had at leasta high school degree. Linear regressionassessed the relationship between Pb doseand neurobehavioral function adjusting forthe covariates.Mean (SD) tibial Pb 14(9.3) μg/gMean (SD) peak tibial bonePb (extrapolated back using aclearance half-time of Pb intibia of 27 yrs) 24(17.4) μg/gMean (SD) DMSA chelatablePb 19 (17.2) μg (urinecollected for 4 hrs)Peak tibial Pb was a significant predictor of poorer performance onVocabulary (∃=!0.063, p = 0.02), serial digit learning (∃=!0.043,p = 0.04), RAVLT trial 1 (∃=!0.054, p = 0.03), RAVLT recognition(∃=!0.019, p = 0.03), Trails B (∃=!0.002, p = 0.03), finger tappingnondominant (∃=!0.042, p = 0.02), Purdue pegboard dominant(∃=!0.043, p = 0.00), nondominant (∃=!0.49, p = 0.00), both(∃=!0.038, p = 0.00), assembly (∃=!0.133, p = 0.00), and Stroop(∃=!0.014, p = 0.00).Current tibial Pb had similarassociations – Vocabulary (∃= 0.103,p = 0.04), Digit Symbol (∃=!0.095, p = 0.05), finger tappingdominant (∃=!0.87, p = 0.02), finger tapping nondominant(∃= 0.102, p = 0.00), Purdue Pegboard dominant (∃=!0.065,p = 0.01), nondominant (∃=!0.091, p = 0.00), both (∃=!0.068,p = 0.00), assembly (∃=!0.197, p = 0.03 ), and Stroop (∃= 0.017,p = 0.01).DMSA-chelatable Pb was only significantly associated with choicereaction time (∃=!0.001, p = 0.01).

# AX6-64Table AX6-3.8 (cont’d). Occupational Exposure to Organolead and Inorganic Lead in AdultsReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationUnited States(cont’d)Stewart et al. (2002)U.S.From the above group of former organoleadworkers 535 were re-examined twice or fourtimes over a four yr period. Also anonexposed control group of 118 had repeatexaminations. Mean age at first visitexposed/controls 56 (7.4)/59 (7.0),percentage with at least a high schooleducation 66/71.2.1st examinationMean (SD) blood Pb 5(2.7) μg/dLMean (SD) tibia Pb 14(9.3) μg/gMean (SD) peak tibia Pb23 (16.5) μg/gMean (SD) exposure duration8 (9.7) yrsMean (SD) duration since lastexposure 16 (11.7) yrsOn 17 of 19 neurobehavioral tests, former organolead workersdemonstrated greater annual decline in adjusted test scorescompared to controls with significant differences for Rey complexFigure copy, RAVLT Trial 1 and RAVLT recognition. Annualdeclines in performance showed greater age-related change in Pbworkers compared to controls for block design, digit symbol,serial digit learning, finger tappingand Trails A. Blood Pb did notpredict annual change scores butpeak tibial Pb did for symboldigit, Rey Complex Figure delayed recall, RAVLT trial 1,RAVLT delayed recall, Purduepegboard (1 measure) and theStroop. For these 6 tests it was determined that an increase of15.7 μg/g bone mineral of peak tibia Pb was equivalent in itseffect on annual test decline to 5 more yrs of age at baseline.Authors conclude that data supports ongoing cognitive declineassociated with past occupational exposure to Pb.Balbus et al. (1997)U.S.222 organolead manufacturing workers,mean age 44 (8.7) yrs and 62 nonexposedreferents, mean age 43 (10) yrs performedsimple visual reaction time (SVRT). Linearregression examined relationship between Pbexposure and mean RT, median RT andstandard deviation of RT after controlling forcovariates.Mean (SD) blood Pb 20(9.5) μg/dLMean (SD) peak urine Pb level143 (130) μg/LBalbus et al. (1998)U.S.A second publication further examined theabove data for relationship of interstimulusinterval (ISI) and Pb exposure.Same as above Short ISIs of 1-3 secondshad no relationship with Pb exposurewhile ISIs of 4-6 seconds were significantly associated with bloodPb (∃= 0.06 [SE 0.02], p = 0.02 along with ISIs of 7-10 seconds(∃= 0.05 [SE 0.02], p = 0.03). ISIs7-10 seconds with peak urinePb levels (∃= 64.29 [SE 21.86], p < 0.01).

# AX6-65Table AX6-3.8 (cont’d). Occupational Exposure to Organolead and Inorganic Lead in AdultsReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationUnited States(cont’d)Stewart et al. (2002)U.S.Population as described in Stewart et al.(1999) and Schwartz et al. (2000b). Dataon 20 neurobehavioral tests from 529former organolead workers wereevaluated to determine if the previouslydescribed relationship with bone Pblevels is influenced by the apolipoproteinE (ApoE) genotype.In 20 linear regression models, coefficients for the ApoE and tibia Pbinteraction term were negative in19 with significance reached for digitsymbol (∃=!0.109 [SE 0.054], p#0.05), Purdue pegboard dominant(∃= 0.068 [SE 0.028], p#0.05) and complex reaction time (∃=!0.003[SE 0.001], p#0.05) and borderline significance existed for symbol digit(∃=!0.046 [SE 0.026], p#0.10), Trails A (∃=!0.303, [SE 0.164]p#0.10) and Stroop (∃=!0.013 [SE 0.008], p#0.10). The slope of therelation between tibia Pb and neurobehavioral outcome was morenegative in those individuals with at least oneε4 allele than individualswithout this allele.It is suggested thatthe presence of one Apo-ε-4 alleleincreases the risk of persistent central nervous system effects of Pb.Tassler et al. (2001)U.S.490 former organolead workers, meanage 58 (7.5) yrs. The peripheral nervoussystem was examined with sensorypressure thresholds, and pinch and gripstrength.Mean (SD) blood Pb 5(2.6) μg/dLMean (SD) DMSA-chelatable Pb19 (16.3) μgMean (SD) current tibia Pb15 (9.4) μg/gMean (SD) peak tibia Pb 24(17.6) μg/gNo strong association was found between Pb biomarkers and measuresof sensory and motor function after adjusting for age. The authorsattributed the findings to decreased sensitivity of the peripheral nerves inthis dose range of inorganic Pb or thepossibility of differential repair inthe peripheral nervous system compared to the central nervous system.Bolla et al. (1995)U.S.190 current workers in organoleadmanufacturing (from the 222 described inSchwartz et al., 1993) mean age 45 (8)yrs compared to 52 referents, mean age45 (8) yrs and 144 solvent exposedworkers, mean age 42 (8) yrs.IH found organic Pb was 65 to70% of exposure in productionarea.Mean (SD) weighted avg bloodPb 24 (9.4) μg/dLPb and solvent exposure associated with adverse effects on tests ofmanual dexterity. When compared to the solvent group Pb exposure hadgreater impairment on memory andlearning and less on executive/motortests. An elevated neuropsychiatric score was present in 43% of the Pbgroup, 15% of the solvent and 7% of the referent group.Mitchell et al. (1996)U.S.58 organolead workers, self-selected fora clinical evaluation. Mean age 45 (7.1)yrs.Mean (SD) blood Pb 19(6.5) μg/dLMean (SD) lifetime blood Pb 26(9.1) μg/dLMean (SD) lifetime urine Pb 51(18.8) μg/LThe most common symptoms were memory loss 74%, joint pain 56%,trouble sleeping 54%, irritability 51%, paresthesia 49%, fatigue 49%,nightmares 35%, moodiness 28%, headaches 21% and depression 21%.Of the 31 workers receiving nerve conduction studies, 29% were normal,carpal tunnel syndrome 36%, cubital tunnel syndrome 3%, medianneuropathy 3%, ulnar neuropathy 23%, mononeuropathy in lowerextremity 5%, tarsal tunnelsyndrome 7% and sensorimotorpolyneuropathy 36%. 39 workers hadneurobehavioral evaluation with64% had abnormal tests of which 46% were considered to be consistentwith a toxic exposure.

# AX6-66Table AX6-3.9. Other Neurological Outcomes Associated with Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited StatesLouis et al. (2005)New York63 cases of essential tremor(ET) and 101 controls,similar for age, 67 (16.6) and65 (11.1) yrs, education,gender and ethnicity wereexamined for interaction ofblood Pb and ALAD genepolymorphisms and increasedodds of ET.ETMean (SD) blood Pb 4 (2.2) μg/dLControlsMean (SD) blood Pb 3 (1.5) μg/dL2 ET cases but no controls had blood Pb>10 μg/dLOf the 63 ET cases 18 (29%) vs. 17 (17%) of 101 controls had anALAD2 allele (OR = 1.98 [95% CI: 0.93, 4.21]; p = 0.077). Whenlog blood Pb was examined by presence of ALAD2 allele in ET, logblood Pb was highest in ET cases with and ALAD2 allele,intermediate in ET cases without an ALAD2 allele and lowest incontrols (test for trend,∃= 0.10; p = 0.001). When ALAD2 allelewas present, blood Pb was significantly associated with odds of ET(OR = 80.29 [95% CI: 3.08, 2.096]; p = 0.008). This increasedodds of ET with an ALAD2 allelewas 30 times greater than in anindividual with only an ALAD1 alleles. In the highest log blood Pbtertile, ALAD2 allelewas present in 22% of ET cases and 5% ofcontrols. It was proposed that increased blood Pb along with theALAD2 allele could affect the cerebellum and thereby increase therisk of tremor.Louis et al. (2003)New York100 cases of ET and 143controls matched for age, sex,and ethnicity.The relationship betweenblood Pb and ET wasexamined.ETMean blood Pb 3 μg/dLControlsMean blood Pb 2 μg/dLTen cases and 7 controls had bonePb levels measured that weresignificantly correlated with blood Pb suggesting that higher bloodPb may have occurred in the past. Total tremor score wascorrelated with blood Pb (r = 0.14, p = 0.03). Logistic regressionadjusting for age and current cigarette smoking found the odds ratiofor ET was 1.19 (95% CI: 1.03, 1.37) per unit increase in blood Pb.Blood Pb was higher in those 39 ET cases with no family history.Both current and lifetime prevalence of occupational Pb exposurewas the same in ET cases and controls but those with history ofoccupational exposure did have a higher blood Pb than thosewithout this history (median, 3.1 μg/dL vs. 2.4 μg/dL, p = 0.004).Kamel et al. (2002)Massachusetts109 cases of ALS and 256controls matched for age, sexand region of residenceexamined the relation of Pband ALS.Cases/controlsMean (SD) blood Pb 5 (0.4) / 3 (0.4) μg/dL3 cases and no controls had blood Pb >10 μg/dLMean (SD) patella Pb 21 (2.1) / 17 (2.0) μg/g5 cases and 1 control had patella Pb levels>50 μg/gMean (SD) tibia Pb 15 (1.6) / 11 (1.6) μg/g2 cases and no controls had tibia Pb >50 μg/g.Increased risk of ALS was foundfor history of occupational Pbexposure (adjusted OR = 1.9 [95% CI: 1.1, 3.3]) increased lifetimedays of exposure (adjusted OR = 2.3 [95% CI: 1.1, 4.9]).Association of blood Pb and ALS (adjusted OR = 1.9 [95% CI: 1.4,2.6]). Elevation in both blood Pband patella and tibia bone Pb wasfound in ALS cases though the precision of these measurementswas questioned (Patella Pb adjusted OR = 3.6 [95% CI: 0.6, 20.6]and tibia Pb adjusted OR = 2.3 [95% CI: 0.4, 14.5]). Therefore,this study found Pb exposure fromhistorical questionnaire data andbiological markers associated with ALS.

# AX6-67Table AX6-3.9 (cont’d). Other Neurological OutcomesAssociated with Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited States(cont’d)Kamel et al. (2003)MassachusettsAs above, the same data was used todetermine the associations of ALS withpolymorphism in ALADand the vitamin Dreceptor (VDR) and the influence ofgenotype.Same as above The ALAD2 allele was associated with a 2-fold increase risk of ALSafter adjustment for the covariates, age, sex, region, education andphysical activity adjusted (OR =1.9 [95% CI: 0.60, 6.3]).Additionally adjusting for blood Pbstrengthened the association ofALAD2 and ALS risk adjusted (OR = 3.6 [95% CI: 0.9, 15]). Thiswas not found for bone Pb or occupational history of Pb exposure(patella-adjusted OR = 2.1 [95% CI:0.61, 6.9]; tibial-adjusted (OR =2.2 [95% CI: 0.66, 7.3]; occupational history-adjusted(OR = 2.4 [95% CI: 0.67, 8.7]). VDR was not associated with Pb orALS risk.Armon et al. (1991)MinnesotaA case-control design with 47 ALS patients,mean age 61 with involvement of upper andlower motor neurons and 201 controls, meanage 62. For the Pb exposure analysis 45 malematched pairs were examined.Lifetime exposure to Pb of200 hrs or more (yrs on job xhrs spent per wk)Of 13 discordant pairs for Pb exposure, 11 were in ALS patient. Therelative risk was 5.5 (95% CI: 1.44, 21.0). A dose-response wasweakened by 3 controls with highest lifetime exposure. Men withALS worked more often at blue collar jobs and significantly moretime welding (p < 0.01). These results expanded a prior pilot studythat found a higher incidence of heavy metal exposure in ALS cases.EuropeChancellor et al.(1993)Scotland1990-1991A case-control design 103 ALS patients fromthe Scottish Motor Neuron Disease Registerand matched community controls.Differences in potential occupationalexposures were determined between casesand controls.Exposure to Pb obtained bylifetime employment historyfrom Office of Population andCensuses and Surveys.Physician’s record review anddirect interview questionnaire.Odds ratio for manual labor in ALS patients was 2.6 (95% CI: 1.1,6.3). Occupational exposure toPb was more common in ALSpatients (OR = 5.7 [95% CI: 1.6, 30]).Gunnarsson et al.(1992)Sweden1990A case-control study of 92 cases of MNDand 372 controls. MND included ALS,progressive bulbar paresis (PBP), andprogressive muscular atrophy (PMA).Relation of MND to risk factors includingoccupational exposure examined.Exposure informationobtained by self-administeredquestionnaire.Exposure to heavy metals primarily from welding had an increasedMantel-Haenszel OR = 3.7 [95% CI: 1.1, 13.0].

# AX6-68Table AX6-3.9 (cont’d). Other Neurological OutcomesAssociated with Lead Exposure in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationEurope(cont’d)Guidetti et al. (1996)ItalyA retrospective incidence, prevalence, andmortality survey of ALS in northern Italywas performed.Mean air Pb 3 μg/m3in1975 to 1 μg/m3in 1985;blood Pb in monitoredchildren decreased 18, 14,and 11 μg/dL in same timeperiod.The area studied had documented Pb pollution for yrs. Based upon79 cases incidence and prevalence rate were comparable to thesurrounding area.Vinceti et al. (1997)Italy19 ALS cases, mean age 66 (14) yrs and39 controls, mean age 64 (12.9) yrs.Sporadic ALSMean (SD) blood Pb 13(6.8) μg/dLControlsMean (SD) blood Pb11 (4.4) μg/dLThere were no cases familial ALS. Blood Pb between ALS casesand controls was not significantly different. Blood Pb was associatedwith disability due to ALS but no support was found for involvementof Pb in the etiology of sporadic ALS.

# AX6-69 

# ANNEX TABLES AX6-4

# AX6-70Table AX6-4.1. Renal Effects of Lead in the General PopulationReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationUnited StatesKim et al. (1996)Boston, MA1979-1994459 men in the Normative Aging Study; periodicexams every 3-5 yrs.Mean serum creatinine at baseline1.2 mg/dLRandom effects modeling, adjusting for baseline age,time since initial visit,body mass index, smokingstatus, alcohol ingestion, education level,hypertension (defined as blood pressure≥160 or 95mm Hg or anti-hypertensive medication use), and, inlongitudinal analysis, baseline serum creatinine andtime between visits.Mean (SD) blood Pb atbaseline9.9 (6.1) μg/dLBlood Pb levels from storedred blood cells were adjustedfor hematocrit; the assay andadjustment procedure werevalidated against freshlycollected samples. Storagetubes were shown to be Pbfree.Cross-sectionalPositive association between log transformed blood Pband concurrent serum creatinine. 10-fold higher blood Pblevel associated with 0.08 mg/dL higher serum creatinine(95% CI: 0.02, 0.13).Association stronger in participants with lower peak bloodPb levels.∃coefficient (95% CI) in the 141 participantswhose peak blood Pb#10 μg/dL: 0.06 (95% CI: 0.023,0.097).LongitudinalPositive association between log transformed blood Pband change in serum creatinine over subsequent follow-upperiod in participants whose peak blood Pb was#25 μg/dL∃coefficient 0.027 (95% CI: 0.0, 0.054)Slope of age-related increase in serum creatinine steeper ingroup with highest quartile of time weighted avg Pbexposure compared to the lowest quartile.

# AX6-71Table AX6-4.1 (cont’d). Renal Effects of Lead in the General PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Muntner et al. (2003)U.S.1988-1994Blood Pb levels measured in 15,211 adult subjects enrolled inthe NHANES III study.Study cohort representative of U.S. population; non-HispanicAfrican Americans, Mexican Americans, the elderly andchildren over-sampled to allow stable estimates in these groups.Hypertension defined as blood pressure∃140 and/or 90 mm Hgand/or current antihypertensive medication use. Based onevidence of interaction between blood Pb and hypertension, thepopulation was stratified by hypertension for further analysis.4,813 hypertensives; 10,398 normotensives.Elevated serum creatinine (%)Defined as∃99th percentile of each race-gender specificdistribution for healthy young adults [age 20-39 withouthypertension or diabetes].11.5 % (hypertensives)1.8 % (normotensives)Chronic kidney disease (%)Chronic kidney disease defined as GFR <60 mL/min/1.73 m2;estimated by MDRD equation (Levey et al. [1999]).10 % (hypertensives)1.1% (normotensives)Multiple logistic regression.Age, race, gender, diabetes,systolic blood pressure, smokingstatus, history of cardiovascular disease, body mass index,alcohol consumption, householdincome, marital status, andhealth insurance.Mean (SD) blood Pb4.21 (0.14) μg/dL(hypertensives)3.30 (0.10) μg/dL(normotensives)Higher odds ratios of both increased serum creatinineand chronic kidney disease by quartile of blood Pb inhypertensives but not in normotensives.HypertensivesOdds ratios for elevated serum creatinine after fulladjustment:Blood Pb (range,μg/dL)%Odds ratio (95% CI)Quartile 1 (0.7 to 2.4) 7.2 1.00Quartile 2 (2.5 to 3.8) 12.1 1.47 (1.03, 2.10)Quartile 3 (3.9 to 5.9) 12.4 1.80 (1.34, 2.42)Quartile 4 (6.0 to 56.0) 16.3 2.41 (1.46, 3.97)p < 0.001 for chi-squared test for trend.Odds ratios for chronic kidney disease after fulladjustment:Blood Pb%Odds ratio (95% CI)Quartile 1 6.1 1.00Quartile 2 10.4 1.44 (1.00, 2.09)Quartile 3 10.8 1.85 (1.32, 2.59)Quartile 4 14.1 2.60 (1.52, 4.45)p < 0.001 for chi-squared test for trend.Associations were similar when Pb was entered as a logtransformed continuous variable.In non-hypertensives, higherblood Pb was associatedwith a higher prevalence of chronic kidney disease, butnot elevated serum creatinine, in diabetics.

# AX6-72Table AX6-4.1 (cont’d). Renal Effects of Lead in the General PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Payton et al. (1994)Boston, MA1988-1991Blood Pb levels measured in 744 men enrolled in theNormative Aging Study.Serum creatinine1.3 mg/dLMeasured creatinine clearance88.2 mL/minCalculated creatinine clearance71 mL/minMultiple linear regression adjusting for age, bodymass index, analgesic anddiuretic use, alcoholconsumption, smoking status, systolic/ diastolic bloodpressure.Mean blood Pb8.1 μg/dLBlood Pb levels below thelimit of detection of 5 μg/dLwere recoded as 4 μg/dL (nnot stated).In blood Pb negatively associated with ln measuredcreatinine clearance (∃=!0.04 [95% CI:!0.079,!0.001]).10 μg/dL higher blood Pb associated with a 10.4 mL/minlower creatinine clearance.Borderline significant associations (p < 0.1) betweenblood Pb and both serum creatinine (∃= 0.027; neither SEnor CI provided) and estimated creatinine clearance(∃=!0.022; neither SE nor CI provided).Shadick et al. (2000)Boston, MA1991-1996777 participants in all male Normative Aging Study.Mean blood Pb5.9 μg/dLMean tibia Pb20.8 μg/g bone mineralMean patella Pb30.2 μg/g bone mineralA significant association between patella Pb and uric acid(∃= 0.0007 [95% CI: 0.001, 0.013]; p = 0.02) was found,after adjustment for age, BMI, diastolic blood pressure,alcohol ingestion, and serum creatinine. Borderlinesignificant associations between tibia (p = 0.06) and bloodPb (p = 0.1) and uric acid were also observed. Notablythese associations were significant even after adjustmentfor blood pressure and renal function, providing furtherevidence that low level Pb increases uric acid. Fifty-twoparticipants had gout; Pb dose was not associated with riskfor gout.

# AX6-73Table AX6-4.1 (cont’d). Renal Effects of Lead in the General PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Tsaih et al. (2004)Boston, MA1991-~2001448 men enrolled in the Normative Aging Study.Baseline Serum Creatinine1.3 mg/dLLongitudinal analysis of data from 2 evaluations amean of 6 yrs apart.Annual change in serum creatinine = (follow-upserum creatinine – baseline serum creatinine) / yrs offollow-up.Covariates assessed = age,age squared, body massindex, hypertension (defined as blood pressure∃160or 95 mm Hg or physician diagnosis with use ofantihypertensive medication), diabetes (defined as useof oral hypoglycemic drugsor insulin or reportedphysician diagnosis), smoking status, alcoholconsumption, analgesic use, and, in longitudinalmodels, baseline serum creatinine and its square.Six percent and 26% of subjects had diabetes andhypertension, at baseline, respectively.Mean (SD) baseline blood Pb6.5 (4.2) μg/dLMean (SD) baseline tibia Pb21.5 (13.5) μg/g bone mineralMean (SD) baseline patella Pb32.4 (20.5) μg/gMean blood Pb levels and serum creatinine decreasedsignificantly over the follow-up period in the group. Pbdose not associated with change in creatinine overall.Significant interaction of blood and tibia Pb with diabetesin predicting annual change in serum creatinine.∃(95% CI) for natural ln baseline blood Pb 0.076 (0.031,0.121) compared to 0.006 (!0.004, 0.016) for nondiabetics.∃(95% CI) for natural ln baseline tibia Pb 0.082 (0.029,0.135) compared to 0.005 (!0.005, 0.015) for nondiabetics.Significant interaction of tibia Pb with hypertensive statusin predicting annual change in serum creatinine.∃(95% CI) for natural ln baseline tibia Pb 0.023 (0.003,0.019) compared to 0.0004 (!0.001, 0.002) for nonhypertensives.Follow-up serum creatinine wasalso modeled separatelyin longitudinal analyses; diabetes modified the associationbetween baseline tibia Pb and follow-up serum creatinine.

# AX6-74Table AX6-4.1 (cont’d). Renal Effects of Lead in the General PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Wu et al. (2003a)Boston, MA1991-1995709 men enrolled in the Normative Aging Study.Serum creatinine1.2 mg/dLCalculated creatinine clearance71.3 mL/minSerum uric acid6.5 mg/dLMultiple linear regression, adjusting for age, bodymass index, blood pressureor HTN (depending onmodel), and alcohol ingestion.Uric acid models alsoadjusted for serum creatinine, other outcome modelsadjusted for smoking statusand analgesic medicationuse.Mean (SD) blood Pb6.2 (4.2) μg/dLMean (SD) tibia Pb22 (13.4) μg/g bone mineralMean (SD) patella Pb32.1 (19.5) μg/g bone mineralSignificant inverse association between patella Pb andcreatinine clearance.∃=!0.069, SE not providedBorderline significant (p = 0.08) inverse associationbetween tibia Pb and creatinine clearance. Borderlinesignificant (p = 0.08) positive associations between tibiaand patella Pb and uric acid.No Pb measure significantlyassociated with serum creatinine.ALAD gene polymorphismalso assessed. 114participants had the ALAD2 variant allele (7 werehomozygous). None of the three renal outcomes differedby genotype. Effect modification by genotype on theassociation between tibia Pb and serum creatinine wasobserved; the beta coefficient (and slope) was greater inthe group with the variant allele (∃= 0.002 [SE notprovided]; p = 0.03).Effect modification of borderline significance (p < 0.1) onrelations between of patella and tibia Pb with uric acid wasobserved; this was significant inparticipants whose patellaPb levels were above 15μg/g bone mineral (∃= 0.016 [SEnot provided]; p = 0.04 ). Similar to the serum creatininemodel, patella Pb was associated with higher uric acid inthose with the variant allele.Genotype did not modify Pbassociations in models of estimated creatinine clearance.

# AX6-75Table AX6-4.1 (cont’d). Renal Effects of Lead in the General PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEuropeAlfven et al. (2002)SwedenOSCAR StudyDate not providedN = 479 men, 542 women. All resided near twobattery plants, 117 participants were current or formerworkers from plants.Renal outcome = urinaryα1microglobulin.Multiple linear regression.Age, smoking status, gender (by stratification),blood cadmium.Mean blood Pb0.16 μmolg/L men0.11 μmolg/L womenBlood Pb not associated with urinaryα1microglobulin(regression performed separately in men and women).Akesson et al. (2005)Women’s Health inthe Lund Area Study,1999-2000N = 820 womenRenal outcomes = GFR (estimated with cystatin C),estimated creatinine clearance,urinary NAG andα1microglobulin.Multiple linear regression.Age, body mass index, diabetes, hypertension, andregular use of nephrotoxic drug, blood and urinarycadmium (in separate models), smoking status(by stratification).Mean blood Pb2.2 μg/dLBlood Pb negatively associated with estimated GFR andcreatinine clearance. No associations with NAG orα1microglobulin.∃(95% CI) for association between blood Pb (μg/dL) andestimated creatinine clearance (mL/min) is!1.8(!3.0,!0.7).

# AX6-76Table AX6-4.1 (cont’d). Renal Effects of Lead in the General PopulationReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationEurope(cont’d)De Burbure et al.(2003)FranceStudy date not provided600 adults (399 exposed, 201 age and gender matched controls).400 children (200 exposed, 200 age and gender matched controls).Age ranged from 8.5 to 12.3 yrs.Exposure from residence near smelters.Exclusion criteria for children included obesity, diabetes, and puberty;for adults included pregnancy, cancer, diabetes, and kidney disease.Serum creatinine1.43 mg/dL (adult male controls)1.38 mg/dL (exposed adult males)1.33 mg/dL (adult female controls)1.26 mg/dL (exposed adult females)Urinary∃2-microglobulin68.16 μg/g creatinine(adult male controls)76.29 μg/g creatinine (exposed adult males)63.79 μg/g creatinine (adult female controls)71.98 μg/g creatinine (exposed adult females)87.8 μg/g creatinine (boy controls)97.3 μg/g creatinine (exposed boys)88.2 μg/g creatinine (girl controls)94.8 μg/g creatinine (exposed girls)Urinary NAG1.12 IU/g creatinine (adult male controls)1.24 IU/g creatinine (exposed adult males)0.98 IU/g creatinine (adult female controls)1.28 IU/g creatinine (exposed adult females)2.29 IU/g creatinine (boy controls)1.70 IU/g creatinine (exposed boys)2.21 IU/g creatinine (girl controls)1.07 IU/g creatinine (exposed girls)Urinary RBP82.8 μg/g creatinine(adult male controls)85.8 μg/g creatinine (exposed adult males)83.42 μg/g creatinine (adult female controls)95.81 μg/g creatinine (exposed adult females)94 μg/g creatinine (boy controls) 99 μg/g creatinine (exposed boys)110 μg/g creatinine (girl controls) 109 μg/g creatinine (exposed girls)Renal outcome measures also included urinary total protein, albumin,transferrin, and brush border antigens.Multiple linear regression adjusting for age, sex, body mass index,area of residence, smoking, alcohol ingestion, mercury, cadmium andurinary creatinine level.Geometric mean bloodPb7.13 μg/dL (adult malecontrols)6.78 μg/dL (exposedadult males)4.17 μg/dL(adult female controls)5.25 μg/dL(exposed adult females)3.42 μg/dL (boycontrols)4.22 μg/dL (exposedboys)2.74 μg/dL (girlcontrols)3.69 μg/dL (exposedgirls)AdultsMean blood Pb level higher in exposed women but notmen. None of the renal outcomes analyzed showedany significant difference between exposed andunexposed groups. After adjustment for covariates,blood Pb was not associated with any renal outcomes.ChildrenMean blood Pb levels higher in exposed. The highestgeometric mean blood cadmium was 0.52 μg/L. Noneof the renal outcomes weresignificantly higher inexposed. After adjustment for covariates, blood Pbwas not associated with any renal outcomes, however,blood cadmium was positively associated with NAG.This association was present in both control andexposed areas.Participants with extremes of urinary creatinineexcluded from data analyses. As a result, number ofsubjects in data tables substantially less than in study.

# AX6-77Table AX6-4.1 (cont’d). Renal Effects of Lead in the General PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Factor-Litvak et al.(1993)Kosovo, Yugoslavia1985-19861447 Yugoslavian women in prospective study ofenvironmental Pb exposure and pregnancy.Exposure from Kosovska Mitrovica with a Pb smelter,refinery, and battery plant. Controls from Pristina, 25miles away.Renal outcome = Proteinuria assessed with a dipstick.Exclusionary criteria included HTN (n = 37 excluded,similar blood Pb levels to remaining participants).Multiple logistic regression adjusting for age (linearand quadratic), height (linearand quadratic), cigarettesmoking, gestational age (linear and quadratic), dailymilk consumption, number of previous live births, avgweekly meat consumption, hemoglobin level andethnic group.Mean blood Pb17.1 μg/dL (582 exposed)5.1 μg/dL (865 controls)Proteinuria (negative, trace, or∃1+)Exposed = 16.2% negative, 74.1% trace and 9.7% with∃1+ proteinuria. Controls = 32.4% negative, 60.6% traceand 7.1% with∃1+ proteinuria. Authors attributed overallhigh proportion of proteinuria to pregnancy.Higher blood Pb associated with increased odds ratio fortrace and∃1+ proteinuria.Comparing women in upper 10th percentile of exposure tolower 10th percentile of exposure, adjusted odds ratios(95% CI) for trace and∃1+ proteinuria was 2.3 (1.3, 4.1)and 4.5 (1.5, 13.6), respectively.Limitations = limited renal outcomes assessed.Staessen et al. (1990)London, EnglandStudy date notprovided531 London civil servants (398 male, 133 female).Exclusionary criteria = occupational exposure toheavy metals.Serum creatinine1.10 mg/dL (men)0.88 mg/dL (women)Mean blood Pb12.4 μg/dL (men)10.2 μg/dL (women)After removal of 2 outliers, the study found no significantcorrelation between serum creatinine and log blood Pb inmen.No correlation between serum creatinine and log blood Pbin women.Limitations = lack of adjustment in data analysis, limitedPb dose and renal outcome assessment, loss of power byanalyzing gender inseparate models.

# AX6-78Table AX6-4.1 (cont’d). Renal Effects of Lead in the General PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Staessen et al. (1992)Belgium1985-1989Blood Pb levels were measured in 1981 adult subjects(965 males, 1016 females) enrolled in the Cadmibelstudy of general Belgian population in four cadmiumpolluted and unpolluted areas.Inclusion criteria included age∃20 yrs and residencein one of four study areas for∃8 yrs. Participantswere randomly selected from the study areas;participation rates were 78% in the two rural areas butonly 39% in the urban areas (one area from eachcategory was known to be cadmium polluted).Measured creatinine clearance99 mL/min (males)80 mL/min (females)Calculated creatinine clearance80 mL/min (males)69 mL/min (females)Multiple linear regression.Covariates assessed included age, age squared, gender(by stratifying), body massindex, blood pressure,ferritin level, smoking status, alcohol ingestion, ruralvs. urban residence, analgesic and diuretic use, bloodand urinary cadmium, diabetes, occupational exposureto heavy metals, and gamma glutamyl transpeptidase.Blood Pb11.4 μg/dL (males)7.5 μg/dL (females)Zinc protoporphyrin alsoassessed.After adjustment, log transformed blood Pb negativelyassociated with measured creatinine clearance.∃coefficient (95% CI)!9.5 (!0.9,!18.1) males!12.6 (!5.0,!20.3) femalesA 10 fold increase in blood Pb associated with a decreasein creatinine clearance of 10 and 13 mL/min in men andwomen, respectively.Log transformed blood Pb alsonegatively associated withcalculated creatinine clearance.∃coefficient (95% CI)!13.1 (!5.3,!20.9) males!30.1 (!23.4,!36.8) femalesLog transformed zinc protoporphyrin negativelyassociated with measured and calculated creatinineclearances and positively associated with serum∃2-microglobulin in both sexes and with serum creatinine inmen.Blood Pb positively associated with serum∃2-microglobulin in men.

# AX6-79Table AX6-4.1 (cont’d). Renal Effects of Lead in the General PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsiaLin et al. (1993)TaiwanStudy date notprovided123 adults living near a Pb battery factory for morethan 10 yrs.Divided into 3 groups by proximity to the factory.Group 1≤500 m (n = 49)Group 2 1000-1500 m (n = 47)Group 3 farther away (n = 27)Exclusionary criteria included history of exposure tonephrotoxicants and nephrotoxicant medications, suchas NSAIDs.24 h urinary NAG excretion3.3 U/day (Group 1)2.4 U/day (Group 3)Multiple linear regression with adjustment for age.Mean blood Pb16.6 μg/dL (Group 1)13.5 μg/dL (Group 2)7.9 μg/dL (Group 3)EDTA diagnostic chelation(done in Group 1)126.1 μg/24 hrsSignificantly higher prevalence of abnormal urinary NAGfound in the exposed group 1 compared to the control group 3(55.6% compared to 11.1%; p < 0.001). However, meanNAG not significantly higher in Group 1.In all 45 participants in whomboth measures were obtained,EDTA chelatable Pb was notcorrelated with urinary NAGexcretion. However, a significant correlation between EDTAchelatable Pb#200 μg/24 hrs and urinary NAG excretion wasobserved in the 39 participants in this group. Furtherevaluation with multiple linear regression, adjusting for age,revealed a∃= 0.034 (95% CI: 0.009, 0.059); p = 0.01.No correlation noted between blood Pb level and urinaryNAG.Limitations = small sample size, plots indicate potential forinfluential outliers.Satarug et al. (2004)Bangkok, ThailandStudy date notprovided118 Thai adults (53 men, 65 women).Renal outcome measures noted below, also includeBUN and total urinary protein.Serum creatinine0.94 mg/dL (males)0.66 mg/dL (females)Urinary NAG4.4 U/g creatinine (males)4.6 U/g creatinine (females)Urinary∃2-microglobulin51 μg/g creatinine (males)29 μg/g creatinine (females)Mean “serum” Pb0.42 μg/dL (males) 0.3 μg/dL(females)Note – cannot determine fromarticle if actually serum Pb(much less commonly used) orblood Pb.Mean urinary Pb1.3 μg/g creatinine (males)2.4 μg/g creatinine(females)Urinary cadmium alsoassessed.In men, urinary Pb excretion correlated only with urinaryprotein at borderline significance (r = 0.22, p < 0.06).In women, urinary Pb excretion correlated with urinary NAG(r = 0.5, p < 0.001), protein (r = 0.31, p = 0.01) and∃2-microglobulin (r = 0.36, p = 0.002) excretion.After adjustment for urinary cadmium, only associationbetween urinaryPb and NAG remained significant.Three urinary renal biomarkers correlated with urinarycadmium, although onlyat borderline significance (p = 0.06)for∃2-microglobulin.Limitations = small sample size, Pb dose assessment sinceonly urine Pb used in renal analyses, limiteddata analysis.

# AX6-80Table AX6-4.1 (cont’d). Renal Effects of Lead in the General PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Satarug et al. (2004)Bangkok, ThailandStudy date notprovided96 Thai men.Subjects subdivided into nonsmokers (n = 53), currentsmokers (n = 27), andex-smokers (n = 16).Renal outcome measures noted below, also includeBUN and total urinary protein.Serum creatinine0.94 mg/dL (nonsmokers)0.93 mg/dL (smokers)0.96 mg/dL (ex-smokers)Urinary NAG4.4 U/g creatinine (nonsmokers)4.2 U/g creatinine (smokers)3.8 U/g creatinine (ex-smokers)Urinary∃2-microglobulin51 μg/g creatinine (nonsmokers)95 μg/g creatinine (smokers)98 μg/g creatinine (ex-smokers)Mean “serum” Pb0.42 μg/dL (nonsmokers)0.9 μg/dL (smokers)0.61 μg/dL (ex-smokers)Mean urinary Pb1.3 μg/g creatinine(nonsmokers)1.4 μg/g creatinine (smokers)1.4 μg/g creatinine (exsmokers)Urinary cadmiumalso assessed.Urinary Pb correlated with urinary protein (r = 0.49,p < 0.01) in smokers and at borderline significance(r = 0.22; p = 0.06) in neversmokers. Also correlatedwith∃2-microglobulin in ex-smokers at borderlinesignificance (r =0.39; p = 0.06).Urinary cadmium correlated with urinary NAG in currentand never smokers and at borderline significance(p = 0.07) in ex-smokers. Also correlated with urinaryprotein and∃2-microglobulin in current smokers and, atborderline significance, in never smokers.Limitations = small sample size, Pb dose assessment sinceonly urine Pb used in renal analyses, limiteddata analysis.Middle EastMortada et al. (2004)EgyptStudy date notprovided68 Egyptian men (35 smokers, 33).Renal outcomes included serum creatinine, BUN, and∃2- microglobulin and urinary albumin, NAG,∃2-microglobulin, alkaline phosphatase, andγ-glutamyltransferase.Mean blood Pb14.4 μg/dL (smokers)10.2 μg/dL (nonsmokers)Pb also measured in urine,hair, and nails.Also measured cadmium, andmercury.Blood and hair Pb levels significantly higher in smokers ascompared to nonsmokers.No significant differences inrenal outcome measures bysmoking status. No correlation between exposure indicesand renal outcome measures.Limitations: small sample size, data analysis – noadjustment.

# AX6-81Table AX6-4.2. Renal Effects of Leadin the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited StatesSmith et al. (1995)U.S.Study date notprovided691 construction workers.96 participants with the ALAD2allele.Mean blood Pb7.8 μg/dL (ALAD11)7.7 μg/dL (ALAD12 or 22)Higher mean BUN (p = 0.03) in participants with theALAD2 allele compared to those with the ALAD11genotype. However, after adjustment for age, alcoholingestion, and blood Pb, the association was no longersignificant. Effect modification was not evaluated.EuropeBergdahl et al. (1997)SwedenStudy date notprovided89 Pb workers; 7 had the ALAD2 allele.34 controls; 10 had the ALAD2 allele.Median blood Pb31.1 μg/dL in Pb workerswith ALAD1128.8 μg/dL in Pb workerswith ALAD12 or 223.7 μg/dL in control workerswith ALAD113.7 μg/dL in control workerswith ALAD12 or 22Higher crude mean serum creatinine (p = 0.11) inparticipants with the ALAD2 allele compared to thosewith the ALAD11 genotype. Adjusted data not presented.

# AX6-82Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationEurope(cont’d)C<rdenas et al. (1993)BelgiumStudy date notprovidedN = 41 Pb smelter workers,41 controls (all males).Study started with 50 Pb smelter workers and 50 controls.Blood Pb level >35μg/dL and exposure >1 yr were requiredin exposed workers. Participants with renal disease, renalrisk factors, such as diabetes or regular analgesic medicationuse, or urinary cadmium >2μg/g creatinine, were excluded.Multiple linear regression; adjusted for urinary creatinineand, in some cases, BMI.Serum creatinine1.02 mg/dL (workers)1.03 mg/dL (controls)Battery of more than 20 renal biomarkers obtainedincluding:RBP68 μg/L (workers)64 μg/L (controls)NAG1.56 U/L (workers)1.21 U/L (controls)Mean blood Pb48.0 μg/dL (workers)16.7 μg/dL (controls)Mean duration of Pbexposure = 14 yrsUrinary cadmium alsomeasured as potentialconfounder.Serum creatinine was not increased in Pb workerscompared to controls; associations between Pb dose andserum creatinine, if assessed, were not specificallyreported.In all 82, blood Pb:-associated with thromboxane B2(∃= 0.36, p < 0.01).-negatively associated with 6-keto-prostaglandin F1 alpha(∃=!0.179, p < 0.01).Zinc protoporphyrin positively associated with sialic acidexcretion.NAG increased in Pb workers butassociated with urinarycadmium.Limitations = sample size, potential for healthy workerbias, limited statistical analysis.

# AX6-83Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Coratelli et al. (1988)Study location anddate not provided;authors from Italy20 Pb battery factory workers.20 controls.12 mo longitudinal study.Renal outcomes = urinary alanine aminopeptidase, NAGand lysozyme.Initial mean blood Pb47.9 μg/dL (workers)23.6 μg/dL (controls)NAG and lysozyme higher inexposed compared tocontrols throughout study.A statistically significantdecline in urinary NAG was noted in association with aone mo period of decreased occupational exposure in thePb workers. NAG correlated with time of exposure(nonlinear) but not blood Pb. Clinical renal functionmeasures were not studied.Fels et al. (1994)Study location anddate not provided81 male Pb workers; 45 age matched controls.Extensive exclusionary criteria.Renal outcomesSerum creatinineGlomerular markers = 6-keto-prostaglandin F1 alpha,thromboxane B2, and fibronectin.Proximal tubular markers = brush border antigens (BBA,BB50, HF5) and intestinal alkaline phosphatase.Distal nephron markers = prostaglandin E2, prostaglandinF2 alpha.Median blood Pb42.1 μg/dL (workers)7.0 μg/dL (controls)Serum creatinine similar in exposed compared to controls.Medians of several markers statistically greater in workerscompared to controls. After adjustment for age anderythrocyte protoporphyrin, several renal marker outcomesshowed “some relation” to blood Pb. The table of thesedata shows r and r2but not beta coefficients making theactual statistical method used unclear.Study limitations include lack of adjustment in statisticalanalysis, potential for healthy worker bias.Garçon et al. (2004)FranceStudy date notprovided35 male nonferrous metal smelter workers.Renal outcomes =α1-microprotein,∃2-microglobulin,retinol binding protein,αandπglutathione S transferases(GST).Oxidative stress markers also measured.All variables log transformed.Mean blood Pb39.6 μg/dLMean blood cadmium5.8 μg/LMean urine cadmium4.7 μg/g creatinineCorrelations between urine Pband cadmium and the renaloutcomes assessed (not blood Pb or cadmium).Significant positive correlations included:urine Pb andαGST (p < 0.01)urine cadmium and RBP (p < 0.05)Also, urine cadmium and 8-OHdG negatively correlated.Limitations = use of urine Pb, lack of adjustment for othercovariates, sample size.Significant correlations between blood Pb and twomarkers of oxidative stresswere observed along with acorrelation between blood cadmium and one marker ofoxidative stress.

# AX6-84Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Gennart et al. (1992)Study location anddates not provided;authors from Belgium98 Pb workers and 85 controls from initial group of 221.Renal outcomes = urinary retinol-binding protein,∃-2microglobulin, albumin, NAG,and serum creatinine and∃-2 microglobulin and estimated creatinine clearance.Exclusionary criteria included lack of exposure to othermetals or solvents, urinary cadmium <2 μg/g creatinine,neurologic or renal disease, certain medications, blood Pblevel >40 μg/dL (workers) and <40 μg/dL for controls.Mean blood Pb51 μg/dL (workers)20.9 μg/dL (controls)Mean duration of employment10.6 yrsMean renal outcomes were not different in workerscompared to controls. Prevalence of abnormalvalues was not greater in workers compared tocontrols. An analysis of variance, in allparticipants, by categorical blood Pb, duration ofemployment, ZPP, and delta-aminolevulinicacid showed no relations with any of the outcomes(data were not shown).Limitations include highPb levels in controls,adjustment only for age in statistical analysis,potential healthy worker bias.

# AX6-85Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Gerhardsson et al.(1992)SwedenStudy date notprovided70 current Pb smelter workers.30 retired Pb smelter workers.31 active and 10 retired truck assembly workers (controls).Renal outcomes = serum creatinine, urinary∃-2microglobulin, NAG, and albumin, clearances ofcreatinine, albumin, relative albumin,∃-2 microglobulinand relative∃-2 microglobulin.Blood Pb measured annually since 1950; time integratedblood Pb index = summation of annual blood Pbmeasurements.Median blood Pb31.9 μg/dL (current Pb workers)9.9 μg/dL (retired Pb workers)4.1 μg/dL (current control workers)3.5 μg/dL (retired control workers)Median time integrated blood Pb index369.9 μg/dL (current Pb workers)1496.1 μg/dL (retired Pb workers)Median calcaneus Pb48.6 μg/g bone mineral(current Pb workers)100.2 μg/g bone mineral(retired Pb workers)Median tibia Pb13.0 μg/g bone mineral(current Pb workers)39.3 μg/g bone mineral(retired Pb workers)3.4 μg/g bone mineral(current control workers)12.0 μg/g bone mineral(retired control workers)Creatinine clearance was higher in Pb workers;p-values not reported for this or other medianvalues between Pb workers and controls.In current Pb workers, blood Pb was positivelycorrelated with urinary∃-2 microglobulin and timeintegrated blood Pb index was correlated withNAG (data not shown).Strengths include assessment of cumulative Pb,inclusion of former workers.Limitations = statistical analysis, lack of powerby stratifying.

# AX6-86Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Pergande et al. (1994)Study location anddate not provided;research team isGerman82 male Pb workers.44 age-matched healthy male volunteers without knownexposure to Pb and living “in areas distant from theexposed people.”Renal outcomes = serum creatinine and∃2microglobulin,urinary albumin and 14 other early biological effectmarkers.Exclusion criteria includedprescription medication useand many diseases; 11 workers and 3 controls excluded.Mean blood Pb42.1 μg/dL (workers)7.0 μg/dL (controls)Erythrocyte protoporphyrinalso measured.Serum creatinine and∃2microglobulin not increased inexposed compared to controlparticipants; correlationswith these outcomes not reported. Blood Pb and/orerythrocyte protoporphyrin correlated with 9 of theurinary renal outcomes.Study limitations include lack of adjustment instatistical analysis, potential for healthy worker bias,potential for differences between exposed and controlgroups.Restek-Samaržijaet al. (1996)CroatiaStudy date notprovided74 patients treated between 1951and 1989 for at least oneepisode of Pb poisoning (53 occupational, 23environmental).Renal outcomes = measured creatinine clearance(collection time not specified), GFR assessed with99mTc-diethylenetriaminepenta-acetic acid (DTPA)clearance.Number of past Pb poisonings negatively correlatedwith creatinine and DTPA clearances.Restek-Samaržijaet al. (1997)CroatiaStudy date notprovided38 patients with occupational Pb poisoning, 23occupationally exposed workers.Renal outcomes = serum creatinine, measured creatinineclearance (collection time notspecified), hippuran renalflow.Mean blood Pb1.5 μmol/L (poisonedworkers)1.6 μmol/L (workers)Creatinine clearance significantly lower in poisonedgroup.

# AX6-87Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Roels et al. (1994)BelgiumStudy date notprovided76 Pb smelter workers (including 21 participants fromCardenas et al. [1993] [Dr.Roels, email communication])68 controls.All males.Matched for age, sex, socioeconomic status, residence, andworkshift characteristics.Extensive exclusionary criteria included renal disease,analgesic abuse, chronic medication for gout, diabetes,occupational exposure to other nephrotoxicants, and priorEDTA chelation.Renal outcomes included serum creatinine and ureanitrogen, measuredcreatinine clearance, NAG, RBP,serum and urinary∃2-microglobulin, as well as other renalearly biological effect markers.Measured creatinine clearance121.3 mL/min/1.73 m2(workers)115.5 mL/min/1.73 m2(controls)Multiple linear regression, adjusted for age, urinarycadmium, hypertension, serum gamma-glutamyltranspeptidase, smoking, exposure status (exposed vs.control), and interaction between exposure variables andhypertension.Mean blood Pb43.0 μg/dL (workers)14.1 μg/dL (controls)Mean tibia Pb66 μg/g bone mineral(workers)21 μg/g bone mineral(controls)Urinary cadmium alsomeasured.Creatinine clearance measured before and after an oralprotein load to determine if eicosanoid changes inCardenas et al. (1993) had clinical implications (Acuteprotein ingestion causes increased renal perfusion andtransient hyperfiltration thought to be mediated bychanges in vasodilator prostanoids. Therefore, it washypothesized that, if the changes noted in Cardenaset al. (1993) were clinically significant, thehyperfiltration response wouldbe diminished in the Pbworkers.).All participants had normal baseline creatinineclearances (>80 mL/min/1.73m2). Both control andPb-exposed workers showed a similar increment increatinine clearance after protein load.However, mean creatinine clearance was statisticallyhigher in Pb workers compared to controls. Log tibiaPb was positively correlated with log measuredcreatinine clearance in the combined group(∃= 0.0319, SE not provided).This was unexpected as the change in eicosanoidsfound in the initial study would not seem to result invasodilatation with increased GFR. Unfortunately, itwas not possible to measure eicosanoid levels in thefollow-up study. No other significant associationsbetween Pb measures and renal outcomes wereobserved. Urinary cadmium associated with NAG.

# AX6-88Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Verschoor et al.(1987)Study location anddate not provided;authors from TheNetherlands155 Pb workers (Pb batteryand plastic stabilizer).126 control industrial workers.Workers with renal disease, HTN, prescriptionmedications excluded.Renal outcomes = BUN, serum creatinine, uric acid,∃2-microglobulin, and RBP, and urinary RBP, NAG,albumin, uric acid,∃2-microglobulin, IgG, and totalprotein. Urine protein electrophoresis performed on subset(n = 25).Cadmium in blood and, in a subset of exposed workers, inurine was also assessed due to this exposure in one planteach from which Pb exposed and control workers weredrawn.Mean blood Pb47.5 μg/dL (workers)8.3 μg/dL (controls)Zinc protoporphyrinalso used as Pb dose measure.Mean renal outcomes in all participants shown bycategorical Pb levels. NAG and RBP higher at bloodPb levels >21 μg/dL compared to those below thislevel (statistical significance not reported). Serum∃2-microglobulin and urinary total protein lower at bloodPb levels >21 μg/dL compared to those below thislevel (again, statistical significance not reported).In simple linear regression models of log transformedurinary total protein,urinary RBP, NAG and serum∃2-microglobulin, higher log transformed blood Pb wassignificantly associated with lower serum∃2-microglobulin and higher RBP and NAG.A matched pair analysis of 55 pairs matched for agewithin 5 yrs, smoking, socioeconomic status, andduration of employment found no differences in renaloutcomes between exposed and controls.Limitations = lack of adjustment, potential for healthyworker bias, occupational cadmium exposure(including in controls) not adequately adjusted.Latin and South AmericaCardozo dos Santoset al. (1994)Study location anddate not provided;authors from Brazil166 Pb battery workers.60 control workers.Renal outcomes = serum creatinine, NAG, urine albumin,and total urinary protein,γ-glutamyl-transpeptidase,alanine-aminopeptidase.Median blood Pb36.8 μg/dL (workers)11.6 μg/dL (controls)Significant results.Median NAG higher in exposed group (p < 0.001).Blood Pb level and duration of exposure correlatedwith NAG in combined group (Spearman’s correlationcoefficients = 0.32 and 0.22,respectively, p < 0.001 forboth).No results mentioned for serum creatinine.Limitations = statistical analysis (no regression forrenal outcomes).

# AX6-89Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationLatin and South America(cont’d)Pinto de Almeidaet al. (1987)Northeast BrazilStudy date notprovided52 primary Pb smelter workers (had to have worked≥5yrs on production line).44 control paper mill workers in same city.All males.Renal outcomes = BUN, serum creatinine, uric acid,proteinuria, creatinine clearance.Only 2 participants excluded for medical reasons.Mean blood Pb64.1 μg/dL (workers)25.5 μg/dL (controls)Also measured zincprotoporphyrin and delta-aminolevulinic acidMean serum creatinine and uric acid higher in exposedthan controls (1.23 vs. 1.1 mg/dL; p < 0.05 and 6.6 vs.4.7 mg/dL; p < 0.001, respectively).Serum creatinine∃1.5 mg/dL present in 32.7% Pbworkers compared to only 2.3% controls.Serum creatinine correlated with duration ofemployment.Limitations = data analysis including lack ofadjustment, several outcomes not analyzed.AustraliaPollock and Ibels(1988)Harbor Bridgeworkers in Sydney,AustraliaStudy date notprovided38 bridge workers.Twenty-four h urine Pb excretion following 1 g of EDTA.Renal outcomes = serum creatinine, creatinine clearance,and 24 h urine protein excretion.Mean (range) blood Pb34.8 (21.8 to 56.2) μg/dL (Pbintoxication)19.9 (9.5 to 26.1) μg/dL(nontoxic)EDTA chelatable Pb range443 to 2366 μg/24 hrs (Pbintoxication)131 to 402 μg/24 hrs(nontoxic)No significant differencesin renal outcomes by Pbexposure group. Two workers in high exposure grouphad evidence of Pb nephropathy.

# AX6-90Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Chia et al. (1994b)Study location notprovided; authorsfrom Singapore1982-1992 (blood Pbmeasurementsobtained every 6 mosover this time)128 Pb workers.152 control workers without Pb or cadmium exposure.Renal outcomes = total NAG, NAG-B isoenzyme(released with lysosomal breakdown assoc with cellmembranes, thought to indicate proximal tubular celltoxicity), NAG-A (released by exocytosis).Cross-sectional outcomes butlongitudinal exposure data.Median blood Pb33.8 μg/dL (workers)8.7 μg/dL (controls)Median cumulative blood Pb(mean of 3.6 blood Pb levelsper worker)208.3 μg·yr/dLMean change in blood Pb(in 6 mos preceding NAGmeasurement)5.8%NAG not different in exposed compared to controlworkers.After adjustment for race, recent change in blood Pbwas significantlyassociated with all NAG outcomes(standardized partial regression coefficients rangedfrom 0.31 for NAG-A to 0.64 for total NAG; neitherSE nor CI provided).In contrast, current blood Pbwas inversely associatedwith NAG-A and NAG-B separately but, oddly, notwith total NAG. Authors do not comment on theseinconsistencies.NAG not associated withcumulative Pb dose.Strengths = longitudinal exposure data.Limitations = data analysis clarity and adjustment.Chia et al. (1994c)SingaporeStudy location notprovided; authorsfrom Singapore1982-1992 (blood Pbmeasurementsobtained every 6 mosover this time)63 Pb workers of >6 mos work duration (median = 3 yrs).91 Pb workers of <6 mos work duration were consideredcontrols.Renal outcomes = urinary BB-50 (brush border antigen inproximal tubule), totalNAG, NAG-B isoenzyme, RBP,α1-microgobulin, albumin and urine and serum∃2-microglobulin.Cross-sectional outcomes butlongitudinal exposure data.Pb dose measures(means or medians not stated)Most recent blood Pb, timeintegrated blood Pb index,relative % change in bloodPb, absolute change in bloodPb, number of times blood Pblevel >40, 50, and 60 μg/dL.Urinary BB-50 higher in exposed compared to recenthire “control” workers.Time integrated blood Pb,number of times blood Pb >40 μg/dL, and relativechange in recent blood Pb were associated withurinary BB-50.Strengths = longitudinal exposure data.Limitations = data analysiscontent (Pb dose means notreported), clarity and adjustment.

# AX6-91Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Chia et al. (1995a)Study location notprovided; authorsfrom Singapore1982-1993 (blood Pbmeasurementsobtained every 6 mosover this time)137 Pb stabilizer workers.Control group of 153 postal workers (older than Pbworkers).Renal outcomes = serum creatinine, four h creatinineclearance, serum∃-2 microglobulin, serumα-1microglobulin, urine albumin.Longitudinal blood Pb data (mean of 4.5 measurementsper Pb worker).Pb dose measures(means or medians not stated)Most recent blood Pb, timeintegrated blood Pb index,relative % change in recentblood Pb, absolute change inrecent blood Pb, number oftimes blood Pb level >40, 50,and 60 μg/dL.In analysis of covariance modeling, adjusted for age and race,mean serumα-1 microglobulin and urine albumin weresignificantly higher in control compared to Pb workers.Serum∃-2 microglobulin was significantly higher in Pbworkers≥30 yrs of age.After adjustment for age, race, and smoking, prevalence ratesfor abnormal values of serum creatinine and∃-2microglobulin were higher in the highest category of timeintegrated blood Pb index in workers∃30 yrs of age(PRR = 3.8 [95% CI: 1.1, 13.3] and 10.3 [95% CI: 3.9,26.9], respectively).Strengths = longitudinal exposure data.Limitations = data analysiscontent (Pb dose means notreported), clarity and adjustment.Chia et al. (1995b)Study location notprovided; authorsfrom Singapore1982-1993 (blood Pbmeasurementsobtained every 6 mosover this time)128 Pb stabilizer factory workers.93 unexposed control subjects (evaluated at preemployment examination; all quit within 1 mo of hire).Blood and urinary cadmium also measured on randomsubset (40 controls and 31 Pb workers).Renal outcomes = serum∃-2 microglobulin and urinaryα1 microglobulin,∃-2 microglobulin, albumin, RBP.Mean recent blood Pb32.6 μg/dL (workers)9.0 μg/dL (controls)Mean time integrated bloodPb index119.9 μg/dLΗyr (workers)0.05 μg/dLΗyr (controls)Mean relative change inrecent blood Pb28.2 % (workers)Mean absolute change inrecent blood Pb6.4 μg/dL/yr (workers)Number of times blood Pblevel >40, 50 and 60 μg/dLOnly urinaryα-1 microglobulin was significantly higher in Pbworkers compared to controls.In multiple linear regression analysis, adjusted only forethnicity and smoking, at least one Pb measure wassignificantly associated with eachof the five renal outcomes.OutcomePb measure∃(95% CI)Uα-1 MG cum. blood Pb 0.10 (0.06, 0.14)Uα-1 MG # blood Pb >50 0.43 (0.04, 0.82)U∃-2 MG cum. blood Pb 0.05 (0.01, 0.09)U RBP # blood Pb >50 0.35 (0.12, 0.59)S∃-2 MG # blood Pb >60 0.47 (0.29, 0.65)U Alb # blood Pb >60 0.66 (0.13, 1.19)Cadmium dose measures reportedly not significant in thesemodels (although power would have been reduced ascadmium measured only in a subset).Strengths = longitudinal exposure data.Limitations = data analysis clarity and adjustment. Overlapin populations between this study and earlier ones possible.

# AX6-92Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Endo et al. (1990)Study location notprovided; authorsfrom Japan198739 male workers.7 female workers (none directly exposed to Pb).Secondary Pb refinery, mean job duration = 10.5 yrsRenal outcomes = BUN, serum creatinine and uric acid,urinary NAG, and tubular reabsorption of phosphate.Mean blood PbRanged from 24.1 to67.6 μg/dL (males)19.6 μg/dL (females)Other Pb measures includedurinary Pb, delta-aminolevulinic acid, andcoproporphyrin.Significant correlations of bloodPb and delta-amino-levulinicacid with BUN and NAG wereobserved. The correlationbetween blood Pb and NAG was dependent on a smallnumber of workers whose bloodPb levels were above80 μg/dL.Limitations include absence of adjustment in statisticalanalysis, small sample size.Endo et al. (1993)Study location anddate not provided;authors from Japan99 male Pb workers.Renal outcomes = serum creatinine and serum and urinealpha-1-microglobulin.Median blood PbRanged from 7.9 μg/dL incategory I consisting of 16office workers who did notwork directly with Pb to76.2 μg/dL in 16 workers inthe highest exposure group(category V).Median urinary alpha-1-microglobulin significantly higher incategories III–V compared to the low exposure group ofoffice workers. This was also the only renal outcome to besignificantly correlated with blood Pb (Spearman rankcorrelation).After alpha-1-microglobulin adjusted for age and blood Pb(by stratifying); few significantdifferences noted. However,analysis approach resulted in substantial loss of power.

# AX6-93Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Hsiao et al. (2001)Taiwan, PR China1991-199830 Pb battery workers.Mean serum creatinine at baseline~ 1.0 mg/dL (based on figure;exact values not provided)Longitudinal Analysis, 8 annual evaluations.Generalized estimating equations used to adjust forautocorrelation in multiple datapoints from eachparticipant.Adjusted for age, gender, and, in models of change inserum creatinine, creatinine at beginning of interval.Mean blood Pb at baseline~35 μg/dL (based on figure;exact values not provided)Mean duration of exposureat baseline13.1 yrsCross-sectionalhigher blood Pb associated with lower concurrentserum creatinine.LongitudinalChange in blood Pb negatively associated withconcurrent change in serum creatinine (p = 0.07).Blood Pb at the beginning of the interval not associatedwith change in serum creatinine in the following yr.Associations may represent Pb-related hyperfiltration.However, as noted by the authors, cumulative Pb dosemay also be a factor. Mean blood Pb declined greatlyjust before renal data collection started. Therefore, theinverse longitudinal associations could be due topersistently elevated cumulative dose (which wasunmeasured but, as evidenced by the long half-life ofbone Pb, likely did not declineas much as blood Pb).However, authors did not model cumulative blood Pbor analyze effect modification by time period, age, orexposure duration to determine if these associationschanged in a pattern consistent with hyperfiltration.The small sample size also limits conclusions that maybe drawn from these results since a small number ofindividuals may be overly influential.Strengths = longitudinal data.Limitations = data analysiscontent (Pb dose means notreported), clarity and adjustment.

# AX6-94Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Huang et al. (1988)Beijing, ChinaStudy date notprovided40 Pb workers (4 women).Control group not described.Renal outcomes = serum beta-2-microglobulin and urinarybeta-2-microglobulin, total protein, IgG.Geometric mean blood Pb40 μg/dLIncreased urinary∃2microglobulin in workerscompared to controls.Multiple limitations including lack of information oncontrol group, data analysis.Jung et al. (1998)KoreaStudy date notprovided75 randomly selected male Pb workers.64 male office workers (controls).Renal outcomes = BUN, serum creatinine, uric acid andurinary NAG, albumin,α1microglobulin and∃2microglobulin.Mean blood PbMeans ranged from 24.3 to74.6 μg/dL (workers)7.9 μg/dL (controls)Other Pb measures includedzinc protoporphyrin,δ-aminolevulinic acid activityand urinary Pb,coproporphyrin, andδ-aminolevulinic acid.Blood Pb, zinc protoporphyrin, and urinaryδaminolevulinic acid significantly correlated with BUN,NAG, andα1microglobulin (appears to be combinedgroup analysis).Limitation = statistical analysis - lack of adjustment.Konishi, et al. (1994)Study locationnot provided;research team fromJapan199199 male Pb workers, including 16 office workers to serveat controls.renal outcomes = fractional clearances ofα1microglobulinand∃2microglobulin (utilizing serum and urinary levels ofboth biomarkers), BUN, serumcreatinine, uric acid andurinary NAG.Median blood PbRange from 7.9 μg/dL incontrols to 76.2 μg/dL inCategory VUrinary NAG,α1microglobulin and fractionalclearance ofα1microglobulin increased with higherblood Pb category. Spearman rank correlation betweenfractional clearance ofα1microglobulin and blood Pbwas significant. This relation also assessed by multiplelinear regression with adjustment for age; bothindependent variables were significantly associatedwith the fractional clearance ofα1microglobulin.Limitation = statistical analysis - lack of adjustment.

# AX6-95Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Kumar andKrishnaswamy(1995)IndiaStudy date notprovided22 auto mechanics volunteers.27 male control workers (from Institute performing study).Renal outcomes = serum creatinine, 4 h creatinineclearance and urinary NAG and∃-2 microglobulin.Renal disease, diabetes, HTN and occupational exposuresexcluded in controls, possibly excluded in workers.Blood Pb range24.3-62.4 μg/dL (exposed)19.4-30.6 μg/dL (controls)Urinary NAG and∃2microglobulin levels weresignificantly higher in exposed compared to controls.However, only NAG was significantly correlated withblood Pb (r = 0.58, p < 0.01).Limitations = study size and lack of adjustment inanalysis, values for 4 h creatinine clearance inabnormal low range in both exposed and controls.Lim et al. (2001)Singapore1999Blood Pb levels every6 mos from 1982 to199955 male Pb workers.Workers followed since 1982, many of same workers as inChia et al. (1995b).Renal outcomes = 4 h creatinine clearance and urinaryalbumin, RBP,α1microglobulin,∃2microglobulin, NAG,NAG-A, and NAG-B.Exclusionary criteria included diabetes, HTN, recentingestion of analgesics, antipyretics, or antibiotics, andthalassemia; 24 participants of the original 80 wereexcluded as a result. One female also excluded.Mean current blood Pb24.1 μg/dLCumulative blood index880.6 μgΗyrs/dL (geometricmean)Number of times blood Pbexceeded 40 μg/dL1.9 (geometric mean)In separate models, after adjustment for age andsmoking, higher categoricalcumulative blood indexand number of times blood Pb exceeded 40 μg/dL wereassociated with lower creatinine clearance (P < 0.001).After adjustment, highernumber of times blood Pbexceeded 40 μg/dL was associated with higher urinaryalbumin,α1microglobulin, RBP, NAG, and NAG-B.Similarly, cumulative blood index was associated withhigher urinary albumin,α1microglobulin, RBP, and∃2microglobulin.No associations between recent blood Pb and any ofthe renal outcomes was observed.Analysis of covariance was used to adjust for smokingand age.Limitation = statistical analysis - lack of adjustment,small sample size, potential for healthy worker bias.

# AX6-96Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Ong et al. (1987)Singapore and JapanStudy date notprovided209 Pb workers (51 females).30 control workers from research staff.Renal outcomes = BUN, serum creatinine, calculatedcreatinine clearance,and urinary NAG.Mean blood Pb42.1 μg/dL (males)31.9 μg/dL (females)Urine Pb also measured.Blood Pb correlated with BUN(r = 0.16; p < 0.01),serum creatinine (r = 0.26; p < 0.001) and creatinineclearance (r =−0.16; p < 0.01). Blood Pb associatedwith NAG after adjustment for age (method notspecified).Higher NAG in exposed compared to controls whenstratified by categorical age.Strengths = sample size.Limitations = statistical analysis - lack of adjustment,urinary NAG not adjustedfor urine dilution.Wang et al. (2002b)TaiwanStudy date notprovided229 Pb battery workers, including 109 females.Renal outcomes = BUN, serum creatinine, serumuric acid.Multiple linear & logistic regression.Adjustment for age, gender,smoking, alcohol ingestion,milk ingestion.Mean blood Pb67.7 μg/dL (males)48.6 μg/dL (females)∃(95% CI) for blood Pb in model of BUN, afteradjustment for Pb job duration/age = 0.062(0.042, 0.082).∃(95% CI) for blood Pb in model of uric acid, afteradjustment for gender and weight = 0.009(0.001, 0.016).Blood Pb not associated serum creatinine.

# AX6-97Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Weaver et al. (2003a)South Korea1997-1999803 Pb workers including 164 females and 94 former Pbworkers.Serum creatinine0.90 mg/dLCalculated creatinine clearance94.7 mL/min4-hr measured creatinine clearance114.7 mL/minRBP63.6 μg/g creatinineNAG215.3μmol/h/g creatinineMultiple linear regression, adjusting for age, gender, BMI,work status (current vs. former worker), HTN or bloodpressure (depending on model), and, for the EBE markers,alcohol ingestion and diabetes.42 associations modeled (7Pb measures with 6 renaloutcomes).Interaction models that assessed effect modification byage in tertiles in 24 associations (4 Pb exposure/dosemeasures with 6 renal outcomes).Mean blood Pb32.0 μg/dLMean tibia Pb37.2μg/g bone mineralMean DMSA-chelatable Pb767.8μg/g creatininePb exposure also assessedwith job duration and threehematologic measures assurrogates for Pb dose(aminolevulinic acid inplasma, zinc protoporphyrin,and hemoglobin).Mean urinary cadmiummeasured insubset (n = 191)1.1 μg/g creatinineAfter adjustment, higher Pb measures associated withworse renal function in 9 of 42 models.Associations in the opposite direction (higher Pbmeasures associated with lower serum creatinine andhigher creatinine clearances) in five models.Opposite direction (inverse)associations observed onlyin models of the clinical outcomes whereas theassociations between higher Pb dose and worse renalfunction were predominantly among the biomarkermodels.In three of 16 clinical renal interaction models, positiveassociations between higher Pb measures and worserenal function in participants in the oldest age tertilewere significantly differentfrom associations in thosein the youngest age tertile which were in the oppositedirection.- This pattern was observed at borderline significance(p < 0.1) in 3 other models.- Pattern was not observed in the EBE marker models.Urinary cadmium associated with NAG.Authors concluded that occupational Pb exposure inthe moderate dose range hasan adverse effect on renalfunction. Inverse associations may representhyperfiltration. Environmental cadmium may have anadverse impact, at least on NAG.

# AX6-98Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Weaver et al. (2003b)Korea Pb workers1997-1999798 Pb workers with genotype information in samepopulation as in Weaver et al. (2003a).79 (9.9%) participants were heterozygous for the ALAD2allele (none was homozygous).89 (11.2%) had VDR genotype Bb or BB.Mean blood Pb31.7 μg/dL (ALAD11)34.2 μg/dL (ALAD12)31.6 μg/dL (VDR bb)34.8 μg/dL (VDR Bb or BB)Mean tibia Pb37.5μg/g (ALAD11)31.4 μg/g (ALAD12)37.1 μg/g (VDR bb)38.1 μg/g (VDR Bb or BB)Data were analyzed todetermine whetherpolymorphisms in the genes encodingδ-aminolevulinicacid dehydratase (ALAD), endothelial nitric oxidesynthase (eNOS), and the vitamin D receptor (VDR)were associated with renal outcomes or modifiedrelations of Pb exposure and dose measures with renaloutcomes.After adjustment, participants with the ALAD2 allelehad lower mean serum creatinine and higher calculatedcreatinine clearance. Effect modification by ALAD onassociations between blood Pb and/or DMSAchelatable Pb and three of six renal outcomes wasobserved. Among those with the ALAD12 genotype,higher Pb measures were associated with lower BUNand serum creatinine and higher calculated creatinineclearance.No significant differences were seen in renal outcomesby VDR genotype nor was consistent effectmodification observed.

# AX6-99Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Weaver et al. (2005a)Korea1997-1999803 current and former Pb workers; 164 females.Serum Uric acid4.8 mg/dLOther renal outcomes as listedin Weaver et al., 2003a.Multiple linear regression.Interaction models that assessed effect modification by agein tertiles.Mean blood Pb32.0 μg/dLMean tibia Pb37.2 (40.4) μg/g bonemineralMean DMSA-chelatable Pb767.8 μg/g creatinineWork to address whether one mechanism for Pb-relatednephrotoxicity, even at current lower levels of Pb exposure, is viaincreasing serum uric acid. Assessed 1) whether Pb dose wasassociated with uric acid and 2) whether previously reportedassociations between Pb dose and renal outcomes (Weaver et al.,2003) were altered after adjustment for uric acid.After adjustment for age, gender,body mass index, and alcohol use,Pb biomarkers not associated with uric acid in all participants.However, in interaction models, both blood and tibia Pb weresignificantly associated in participants in the oldest age tertile(∃= 0.0111 [95% CI: 0.003, 0.019] and 0.0036 [0.0001, 0.007] forblood and tibia Pb, respectively). These models were further adjustedfor blood pressure and renal function. Hypertension and renaldysfunction are known to increase uric acid. However, they are alsorisks associated with Pb exposure.Therefore, adjustment for thesevariables in models of associations between Pb dose and uric acidlikely results in over-control. Onthe other hand, since nonPb relatedfactors contribute to both renal dysfunction and elevated bloodpressure, lack of adjustment likely results in residual confounding.Therefore, as expected, associations between Pb dose and uric aciddecreased after adjustment for systolic blood pressure and serumcreatinine, although blood Pb remained borderline significantlyassociated (∃= 0.0071 [95% CI:!0.001, 0.015]). However, when thepopulation was restricted to the oldest tertile of workers with serumcreatinine greater than the median (0.86 mg/dL), likely the highestrisk segment of the population, blood Pb remained significantlyassociated with uric acid even after adjustment for systolic bloodpressure and serum creatinine (∃= 0.0156).Next, in models of renal function in all workers, uric acid wassignificantly (p < 0.05)associated with all renal outcomes exceptNAG.In models in the oldest tertile ofworkers (266 workers, median age51.1 yrs, range 46.0 to 64.8 yrs), after adjustment for uric acid,associations between Pb dose and NAG were unchanged, but fewerof the previously significant (p#0.05) associations noted between Pbdose and the clinical renal outcomes in Weaver et al. (2003a)remained significant.

# AX6-100Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Weaver et al. (2005b)South Korea1999-2001652 Pb workers including 149 females and 200 formerworkers.Patella Pb measured in the third evaluation of the samestudy reported in Weaver etal. (2003a). Data collectionperformed a mean of 2.2 yrs after collection of the datapresented in Weaveret al. (2003a).Same renal outcomes as Weaver et al. (2003a).Serum creatinine0.87 mg/dLCalculated creatinine clearance97.0 mL/minMultiple linear regression, adjusting for age, gender, BMI,work status (current vs. former worker), HTN or bloodpressure (depending on model), diabetes, smoking status,and, for the clinical measures, use of analgesicsInteraction models assessed effect modification by age,dichotomized at the 67th percentile.Mean blood Pb30.9 μg/dLMean tibia Pb33.6 μg/g bone mineralMean patella Pb75.1 μg/g bone mineralMean DMSA-chelatable Pb0.63μg Pb/mg creatinineAll 4 Pb measures were correlated (Spearman’s r = 0.51 –0.76).Patella, blood and DMSA-chelatable Pb levels positivelyassociated with NAG.Higher DMSA-chelatable Pb associated with lower serumcreatinine and higher calculated creatinine clearance.Interaction modelsAll four Pb measures associated with higher NAG amongparticipants in oldest age tertile.Higher blood, tibia, and patellaPb associated with higherserum creatinine among older participants.-Beta coefficients less in the Pb workers whose ages were inthe younger two-thirds of the age range; difference betweenslopes in the two age groups wasstatistically significant onlyfor association of blood Pb and serum creatinine.Inverse DMSA associations(higher DMSA-chelatable Pbassociated with lower serum creatinine and higher calculatedcreatinine clearance) significant in younger workers.Patella Pb associations were consistent with those of blood andtibia Pb; DMSA-chelatable Pb associations unique.Authors hypothesized that similarities between patella, blood,and tibia Pb associations could be due, in part, to highcorrelations among the Pb biomarkers in this population.Despite similar high correlations, DMSA-chelatable Pbassociations with serum creatinine and calculated creatinineclearance were unique. This biomarker is dependent on renalfunction and the collection timewas only 4 h. Therefore, theamount of Pb that is excreted in this relatively short time periodafter chelation may be influencednot only by bioavailable Pbburden, but also by high-normal aswell as actual supranormalglomerular filtration which are more common in the youngerworkers.

# AX6-101Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Weaver et al. (2005c)Korea1997-1999798 current and former Pb workers.Same population as in Weaver et al. (2003a,b).Data were analyzed todetermine whetherpolymorphisms in the genes encodingδ-aminolevulinicacid dehydratase (ALAD), endothelial nitric oxidesynthase (eNOS), and the vitamin D receptor (VDR)were associated with uric acid or modified relations ofPb exposure and dose measures with uric acid.Uric acid not different by ALAD or VDR genotype.Among older workers (age≥median of 40.6 yrs),ALAD genotype modified associations between Pbdose and uric acid levels. Higher Pb dose wassignificantly associated with higher uric acid inworkers with the ALAD11 genotype; associations werein the opposite direction in participants with the variantALAD12 genotype.Ye et al. (2003)Chinese Pb workersStudy date notprovided216 Pb workers.Renal outcomes = urinary NAG and albumin.Geometric mean blood Pb37.8μg/dL (n = 14 workerswith the ALAD12genotype)32.4μg/dL (n = 212 workerswith the ALAD11 genotype)31.9 μg/dL (VDR bb)41.7 μg/dL (in 20 participantswith VDR Bb or BB)After adjustment for age,NAG was borderline higherin those with the ALAD variant allele whose blood Pblevels were≥40μg/dL (p = 0.06). In all Pb workers,after adjustment for age,gender, smoking, and alcoholingestion, a statistically significant positive associationbetween blood Pb and creatinine adjusted NAG wasobserved in the workers with the ALAD12 genotypebut not in Pb workers with the ALAD11 genotype (thegroups were analyzed separately rather than in aninteraction model).No effect modification by VDR genotype onassociations between blood Pb and urinary albuminand NAG observed (separate analysis reduced power).

# AX6-102Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationMiddle EastAl-Neamy et al.(2001)United Arab EmiratesFeb-June, 1999100 “industrial” workers exposed in a range of industries100 working controls.Matched for age, sex, and nationality.Renal outcomes = BUN, serum creatinine.Mean blood Pb77.5 μg/dL (workers)19.8 μg/dL (controls)Mean BUN and serum creatinine not statisticallydifferent between exposed workers and controls.Limitations = data analysis.Ehrlich et al. (1998)South AfricaStudy date notprovided382 Pb battery factory workers.Mean age = 41.2 yrs.All males.Multiple linear regression adjusted for age, weight, andheight (Covariates assessedfor inclusion also includedsmoking, alcohol ingestion, and diabetes).Clinical renal outcomes included serum creatinine, uricacid, and BUN.Mean serum creatinine1.13 mg/dLRenal early biological effect markers (NAG, RBP,intestinal alkaline phosphatase, tissue nonspecific alkalinephosphatase, Tamm-Horsfall glycoprotein, epidermalgrowth factor, and microalbuminuria) were measured in199 participants randomly selected by tertiles of currentblood Pb.Mean blood Pb53.5 μg/dLMean exposure duration11.6 yrsMean cumulative blood Pb(defined as sum of the avgblood Pb in each yr over all yrsof employment; done in subsetof 246 with past blood Pb data)579.0 (μgΗyr)/dLMean historical blood Pb(defined as cumulative bloodPb divided by yrs of exposure)57.3 μg/dLMean tibia Pb69.7μg/g bone mineral(measured 2 yrs after initialstudy on random sample of 40)After adjustment for age, weight, and height,categorical current and historical blood Pb and zincprotoporphyrin were associated with serum creatinineand uric acid, in separatemodels. Associationsbetween cumulative blood Pb or exposure durationand the renal outcomes were not observed.Among the EBE markers, only current blood Pb wasborderline associatedwith NAG (p = 0.09).Associations with renal dysfunction were observed atblood Pb levels <40μg/dL. Not explained by aneffect on blood pressure since Pb measures notassociated with blood pressure. Blood cadmiummeasured in 56 participants 2 yrs after the initialstudy. All low (#1.2μg/L) suggesting thatoccupational level cadmium exposure was not acontributing factor. Theauthors did implicate Pbbody burden, which was substantial based on meantibia Pb. However, cumulative blood Pb was notassociated in this study and mean tibia Pb in Roelset al. (1994) was similar (in that study a positiveassociation with creatinine clearance was observed).

# AX6-103Table AX6-4.2 (cont’d). Renal Effects ofLead in the Occupational PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationMiddle East(cont’d)El-Safty et al. (2004)EgyptStudy date notprovided45 Pb workers with Pb job duration <20 yrs.36 Pb workers with Pb job duration≥20 yrs.75 control workers.Renal outcomes = urinaryα1-microglobulin, NAG, andglutathione S-transferase.Median urine PbRanged from 15.4 μg/gcreatinine in nonsmokingcontrol workers to 250.4 μg/gcreatinine in smoking Pbworkers with∃20 yrs Pb jobduration.Medians of all 3 renal outcomes significantly higherin Pb workers regardless ofsmoking status (analysisstratified by smoking status).Urine Pb significantly correlated with urinaryα1-microglobulin and glutathione S-transferase innonsmoking Pb workers and with NAG as well insmoking Pb workers.Limitations include using urine Pb as sole Pb dosemeasure and data analysis.Mortada et al. (2001)EgyptStudy date notprovided43 traffic policemen.52 matched control office workers (similar in terms ofage, gender, smoking, and “social life”).Renal outcomes = serum creatinine, beta-2 microglobulin,BUN and urinary∃-2- microglobulin, NAG, alkalinephosphatase,γ-glutamyl transferase, and albumin.Exclusionary criteria included diabetes, HTN, hepatic,renal or urologic diseases.Mean blood Pb32.1 μg/dL (exposed)12.4 μg/dL (controls)Pb also measured in hair, urineand nails.NAG and albumin significantly higher in policemencompared to controls.NAG positively correlated(Pearson’s) with job duration and blood and nail Pb.Urinary albumin positively correlated with jobduration and blood and hair Pb.Limitations: data analysis– no adjustment, use ofparametric correlation techniques with data likely tobe nonparametric; study size.

# AX6-104Table AX6-4.3. Renal Effects of Lead in the Patient PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited StatesOsterloh et al. (1989)Northern CAStudy date notprovided40 male subjects with hypertensive nephropathy(hypertension preceded renal insufficiency; serumcreatinine 1.8-4 mg/dL).24 controls with renal dysfunction from other causes.Patients recruited from the Kaiser Permanente RegionalLaboratory database (large health maintenanceorganization) in northern California.Mean blood Pb7.3 μg/dL (in bothhypertensive nephropathy andcontrols CRI from othercauses)Mean EDTA chelatable Pblevels153.3 μg/72 hrs (hypertensivenephropathy)126.4 μg/72 hrs (control CRI)No significant difference in EDTA chelatable Pblevels; highest chelatable Pb level was609.2 μg/72 hrs.Pb dose and serum creatinine were not correlated.Blood and chelatable Pb levels much lower than thosereported by Wedeen et al. (1983) andSanchez-Fructuoso et al. (1996).Only 17% of their study participants had a history ofpossible Pb exposure based on questionnaire, againmuch lower than the two other studies.Steenland et al. (1990)MichiganDiagnosis from1976-1984325 men with ESRD (diabetes,congenital and obstructivenephropathies excluded).Controls by random digit dialing, matched by age, race,and place of residence.Risk of ESRD significantly related to moonshinealcohol consumption (OR= 2.43), as well asanalgesic consumption, family history of renaldisease, and occupational exposure to silica orsolvents.EuropeBehringer et al.(1986)GermanyStudy date notprovided16 patients with CRI (median serum creatinine =2.2 mg/dL) and gout.19 patients with CRI (median serum creatinine =5.1 mg/dL) without gout.21 healthy controls.Pb excretion in the 96 hrs after administration of 1 gEDTA iv.Median blood Pb7.2 μg/dL (controls)11.5 μg/dL (CRI, no gout)15.3 μg/dL (CRI & gout)Median EDTA chelatable Pb(μg/4 days/1.73 m2)63.4 (controls)175.9 (CRI, no gout)261.3 (CRI & gout)EDTA chelatable Pb higher in gout patients whodeveloped gout after CRI than those in which goutpreceded CRI (statistical test results not mentioned orshown). Authors conclude arole for Pb in patientswith gout occurring in setting of CRI and that Pb maycontributes to renal function decline in establishedrenal disease from other causes.Limitations = small groups, limited data analysis.

# AX6-105Table AX6-4.3 (cont’d). Renal Effects of Lead in the Patient PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Colleoni andD’Amico (1986)Italy(~1982-1985)12 consecutive patients with CRI (mean serumcreatinine = 3.3 mg/dL) and gout, renal diagnosisconsistent with chronic interstitial nephritis in all; 7 hadhistory of occupational Pb exposure.12 controls with chronic glomerulonephritis and nohistory of Pb exposure or gout.Pb excretion in the 48 hrs after administration of 1.5 gEDTA im.Mean EDTA chelatable Pb(μg/48 hrs)180 (CRI, no gout)505 (CRI & gout)Significantly higher EDTA chelatable Pb in thegroup with CRI and gout compared to CRI alone.EDTA chelatable Pb significantly correlated withserum creatinine in patients with CRI and gout butnot CRI alone. Authors conclude that Pb is cause ofCRI with gout but renal insufficiency alone notresponsible for increased Pb body burden (absenceof evidence for reverse causation).Limitations = small sample size, limited dataanalysis.Colleoni et al. (1993)ItalyStudy date notprovidedAll 115 patients on hemodialysisat the time of the study;41 women.Blood Pb data from prior study of 383 healthy controls insame geographical area served as comparison.Mean blood Pb(corrected for hemoglobin)19.9 μg/dL (patients)14.7 μg/dL (controls)Significantly higher mean blood Pb in hemodialysispatients compared to healthy controls. 13% hadblood Pb levels >30 μg/dL.Blood Pb level was notassociated with duration of hemodialysis. Mean Pblevels higher in smokers and in relation to alcoholingestion. Pb not detectable in dialysis fluids.Limited data analysis.Craswell et al. (1987)Germany andAustraliaStudy date notprovidedSee discussion below under Australia.

# AX6-106Table AX6-4.3 (cont’d). Renal Effects of Lead in the Patient PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Fontanellas et al.(2002)SpainStudy date notprovidedALAD/restored ALAD as a possible index of Pb poisoningin chronic renal failure patients.Restored ALAD was measured after the addition ofzinc and dithiothreitol (DTT) to the incubationmedia.The ALAD/restored ALAD ratio was found tocorrelate with the results of the EDTA Pbmobilization test. Patients excreting I,115 to3860 μg Pb per 72 hrs had a ratio of 0.19 whilechronic renal failure patients excreting an avg of322 μg Pb (range 195 to 393) had a ratio of 0.47.In comparison, normal controls had a ratio of 0.5.Jones et al. (1990)Study location anddate not provided;authors from UK27 dialysis patients.59 healthy controls.Mean blood Pb8.1 μg/dL (patients)10.0 μg/dL (controls)Tibia Pb levels not correlated with blood Pb but werecorrelated with Pb inbone biopsy measurements(r = 0.42).Limitations = data analysis.Koster et al. (1989)Study location anddate not provided;authors fromGermany91 patients with CRI (median serum creatinine =2.5 mg/dL).46 age-matched normal controls.Pb excretion in the 4 days after1 g EDTA iv.Mean blood Pb(corrected for hemoglobin)11.2 μg/dL (patients)7.6 μg/dL (controls)Mean EDTA chelatable Pb164.7 μg/4 days /1.73 m2(patients)63.6 μg/4 days /1.73 m2(controls)CRI patients had significantly higher blood andEDTA chelatable Pb levels than controls. In 13% ofthe CRI patients, EDTA chelatable Pb exceeded thehighest value in controls (328.8 μg). EDTAchelatable Pb levels were correlated with serumcreatinine in patients (r = 0.37; p < 0.007).Limitations = data analysis.

# AX6-107Table AX6-4.3 (cont’d). Renal Effects of Lead in the Patient PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Miranda-Carús et al.(1997)Spain1990-199427 patients with gout and CRI.50 patients with gout only.26 controls with normal renal function and no gout.Multiple purine metabolism measures including serumurate, hypoxanthine, and xanthine, as well as theirexcretion, clearance and fractional excretion measures.Mean blood Pb17.8 μg/dL (gout and CRI)14.9 μg/dL (gout only)12.4 μg/dL (controls)Mean EDTA chelatable Pb845 μg/120 hrs (gout and CRI)342 μg/120 hrs (gout only)215 μg/120 hrs (controls)Pb dose measures significantly higher in patients withgout and CRI compared to the other two groups.EDTA chelatable Pb inversely correlated withcreatinine clearance. Each of the 2 patient groupswere dichotomized by EDTA-chelatable Pb level of600μg/120 hrs, resulting in 3 small groups (n rangingfrom 6 to 14) and one group of 44 participants withgout and EDTA chelatable Pbbelow the cut-off. Nosignificant differences in mean purine metabolismmeasures were observed. It is not clear whethercorrelations between EDTA-chelatable Pb and thepurine measures were assessed and if so whether thesmall groups were combinedfor this analysis. Thuslack of power may be onereason for the inconsistencywith Lin’s work. Different Pb body burdens may be afactor as well.Uric acid parameters were unchanged followingchelation in 6 participants with EDTA-chelatableabove 600 μg/120 hrs. Again higher Pb body burdensmay be a factor but the small number and limiteddetails on the group make firmconclusions difficult.Nuyts et al. (1995)BelgiumStudy date notprovidedCase-control study.272 cases with chronic renal failure (all types) matched to272 controls by age, sex and residence.Exposure assessed by 3 industrial hygienistsblinded tocase or control status.Significantly increased odds ratio for chronic renalfailure with Pb exposure (OR = 2.11 [95% CI: 1.23,4.36]) as well as several other metals. Increased riskwith diabeticnephropathy.

# AX6-108Table AX6-4.3 (cont’d). Renal Effects of Lead in the Patient PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Sánchez-Fructuosoet al. (1996)SpainStudy date notprovided296 patients:Group I = 30 normal control subjectsGroup II = 104 patients with essential HTN & normalrenal functionGroup III-A = 68 patients with HTN and CRI of uncertainetiology but presumed nephroangiosclerosisGroup III-B = 64 patients with HTN, CRI, and goutGroup IV = 30 patients with CRI of known etiologyMean blood and EDTA-chelatable Pb levelsGroup I16.7 μg/dL324 μg/72 hrsGroup II16.8 μg/dL487 μg/72 hrsGroup III-A18.5 μg/dL678 μg/72 hrsGroup III-B21.1 μg/dL1290 μg/72 hrsGroup IV16.5 μg/dL321 μg/72 hrsEDTA chelatable Pb >600 μg/72 hrs in 16 patients ingroup II, 30 patients in group III-A, 44 patients ingroup III-B, but no patients in either group I and IV.Mean blood and EDTA chelatable Pb levels in thepatients with CRI ofknown cause were notstatistically different fromcontrols with normal renalfunction. However, baseline urinary Pb excretion waslower in group IV. This provides conflicting evidenceregarding the “reverse causality” hypothesis ofincreased Pb burden due to decreased excretion inCRI.Significant correlations notedbetween bone Pb levels(assessed by biopsy) and EDTA chelatable Pb level in12 patients whose chelatable Pb levels were >600μg/72 hrs; provides support for validity of chelatablePb levels in CRI.A positive correlation was observed between serumcreatinine levels and EDTA-chelatable Pb levels>600 μg/72 hrs but not below this level.In group III, mean measuredcreatinine clearance wassignificantly lower in thosewith EDTA chelatable Pblevels >600μg/72 hrs compared to participants withchelatable Pb <600μg/72 hrs.

# AX6-109Table AX6-4.3 (cont’d). Renal Effects of Lead in the Patient PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Van de Vyver et al.(1988)Belgium, Franceand GermanyStudy date notprovidedTransiliac bone biopsies obtained from:11 cadavers without known Pb exposure and with normalrenal function13 patients with CRI, gout and/or HTN 22 Pb workers153 dialysis patientsMean transiliac Pb levels5.5 μg/g (153 dialysis pts)20.6 μg/g (in highest 5%dialysis pts)3.7 μg/g (in 10 pts on dialysisdue to analgesic nephropathy)6.3 μg/g (11 cadavers)30.1 μg/g (22 Pb workers)In 5% of the hemodialysis patients studied, bone Pbconcentrations approximated the levels found inactive Pb workers, suggesting Pb as a primary causeof their renal failure. Levels in the 10 patients withanalgesic nephropathy were the lowest (all <7 μg/g),evidence against reverse causality.In the combined group of 13 patients with CRI, goutand/or HTN and 22 Pb workers, EDTA chelatable Pbcorrelated with Pb in bone biopsies (r = 0.87).Winterberg et al.(1991)Study location anddate not provided;authors fromGermanyIliac crest bone Pb measured by biopsy in:8 controls8 patients with CRI14 dialysis patientsMean iliac crest bone Pb levels1.63 μg/g (8 controls)2.18 μg/g (8 patients withCRI)3.59 μg/g (in 14 dialysis pts)Noted that the bone Pb levels in patients withanalgesic nephropathy and cadaver controls in Van deVyver et al. (1988) were much higher than in controlgroups of other researchers. They reiterated theconcern that Pb did accumulate due to decreased renalexcretion.Latin and South AmericaNavarro et al. (1992)VenezuelaStudy date notprovided18 dialysis patients.14 controls.Bone (biopsy) and blood levels of Pb and several othermetals.Mean blood Pb5.2 μg/dL (patients)11.5 μg/dL (controls)Mean Pb in bone9.7 μg/g (patients)7.0 μg/g (controls)Blood but not bone Pb significantly higher in patientscompared to controls. Authors concluded that boneaccumulation of aluminum, iron and vanadium, butnot Pb, occurred in dialysis patients.Limitations = sample size, data analysis includinglack of adjustment.

# AX6-110Table AX6-4.3 (cont’d). Renal Effects of Lead in the Patient PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAustraliaCraswell et al. (1987)Germany andAustraliaStudy date notprovidedGerman participants fromindustrialized area wherechronic Pb nephropathy not previously observed.Gp 1 = 8 healthy controls (from hospital staff)Gp 2a = 12 CRI patients, no gout or Pb exposureGp 2b = 7 CRI patients, no gout but + Pb exposureGp 3a = 7 CRI patients with gout but no Pb exposureGp 3b = 6 CRI patients with gout and Pb exposureAustralian participants from Queensland site of knownchronic Pb nephropathy.Gp 1 = 9 healthy controls (from hospital staff)Gp 2a = 14 CRI patients, no gout or Pb exposureGp 2b = 11 CRI patients, no gout but + Pb exposureGp 3a = 25 CRI patients with gout but no Pb exposureGp 3b = 11 CRI patients with gout and Pb exposureCRI defined as serum creatinine≥1.5 mg/dL“Excess” EDTA chelatable Pb defined as Pb excreted over4 days after EDTA minus twice baseline Pb excreted preEDTA.Median blood Pb (hemoglobincorrected)Gp 1German = 6.8 μg/dLAustralian = 11.0 μg/dLGp 2aGerman = 6.2 μg/dLAustralian = 9.1 μg/dLGp 2bGerman = 8.5 μg/dLAustralian = 16.2 μg/dLGp 3aGerman = 10.6 μg/dLAustralian = 12.8 μg/dLGp 3bGerman = 12.0 μg/dLAustralian = 27.1 μg/dLMedian “excess” EDTAchelatable PbGp 1German = 68.4 μgAustralian =82.9 μgGp 2aGerman = 126.4 μgAustralian = 393.7 μgGp 2bGerman = 489.0 μgAustralian = 1181.1 μgGp 3aGerman = 227.9 μgAustralian = 808.1 μgGp 3bGerman = 422.7 μgAustralian = 1077.5 μgUsing nonparametric statistical techniques due toskewed data, German participants excretedstatistically less Pb than their Australian counterparts.Mean EDTA chelatable Pb levels were significantlyhigher in German patients with gout than in thosewithout gout; the observed increase in the Australianpatients was of borderline significance (p < 0.1).Limitations = small groups, limited data analysis.

# AX6-111Table AX6-4.3 (cont’d). Renal Effects of Lead in the Patient PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAustralia(cont’d)Price et al. (1992)Queensland,Australia1981-19868 renal patients compared with age-matched controls.X-ray fluorescence of finger bone Pb conducted twice 5yrs apart.Authors conclude that Pb in bone half-life is similar inrenal patients compared to age-matched controls.Study limitations substantial, however.Limitations = small numbers (although bone Pbmeasured in more patients, many were below the limitof detection, inclusion of outlierswithout formalstatistical analysis.AsiaLin and Lim (1992)Chinese population(likely in Taiwan)Study date notprovided10 healthy controls.10 patients with CRI but no gout.8 patients with gout and subsequent CRI.6 patients with CRI and subsequent gout.Exclusionary criteria included + history of occupational orenvironmental Pb exposure.Mean EDTA chelatable Pb inμg/72 hrs/1.73 m290.2 (controls)98 (CRI, no gout)171.6 (gout, then CRI)359.8 (CRI, then gout)Pb body burden higher in patients with CRI and gout,especially when CRI precedes gout.Limitations = small sample sizes, statistical analysis.Lin and Huang(1994)TaiwanStudy date notprovidedGroup 1 = 10 patients with normal renal function and nogout; Group 2 = 10 patients with CRI (serum creatinine>1.4 mg/dL) and subsequent gout; Group 3 = 20 patientswith CRI but no gout.All males.Pb body burden assessed with 1 g EDTA iv followed by72 hr urine collection.Mean EDTA chelatable PbGp 1 = 60.55 μg/ 72 hrsGp 2 = 252.24 μg/ 72 hrsGp 3 = 84.86 μg/ 72 hrsMean EDTA chelatable Pb and serum uratesignificantly higher in thepatients with gout. Afteradjustment for creatinine clearance, log transformedEDTA chelatable Pb was significantly associated withserum urate levels (∃= 0.757 [95% CI: 0.142, 1.372];p < 0.05), daily urate excretion (∃=!60.15 [95% CI:!118.1,!2.16]; p < 0.05), urate clearance (∃=!0.811[95% CI:!1.34,!0.282]; p < 0.05), and fractionalurate excretion (∃=!1.535 [95% CI:!2.723,!0.347];p < 0.05). EDTA chelatable Pb not associated withcreatinine clearance.Limitations = small sample sizes, limited adjustmentin regression analyses.

# AX6-112Table AX6-4.3 (cont’d). Renal Effects of Lead in the Patient PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Lin and Lim (1994)TaiwanStudy date notprovidedGp 1 = 12 healthy controls.Gp 2 = 10 patients with HTN.Gp 3 = 12 patients with HTN, then CRI (hypertensivenephropathy).Gp 4 = 12 patients with CRI only.Gp 5 = 12 patients with CRI not due to HTN, butsubsequent HTN.Mean EDTA chelatable PbGp 1 = 76.6 μg/72 hrsGp 2 = 67.96 μg/72 hrsGp 3 = 182.9 μg/72 hrsGp 3 = 84.46 μg/72 hrsGp 3 = 92.86 μg/72 hrsHigher mean EDTA chelatable Pb level in Gp 3;5 of 12 had history of gout developing after CRI.Limitations = small sample sizes, limited analyses.Lin et al. (1999)TaiwanStudy date notprovided32 patients selected from 102 patients with serumcreatinine from 1.5–4.0 mg/dL who were followed in theInstitution’s outpatient clinics.Eligibility criteria included serum creatinine from 1.5 –4.0 mg/dL, stable renal function over 6 mos before studyentry; controlled blood pressure and cholesterol; dailyprotein intake <1 g/kg body wt; no known history ofexposure to Pb or otherheavy metals and EDTAchelatable Pb >150 but <600μg/72 h.Exclusionary criteria included potentially reversible orunstable renal disease (i.e., due to systemic diseases suchas lupus and diabetes), andnephrotoxicant medications.Patients divided into 16 patients receiving 1 g EDTA i.v.weekly for two mos and a control group of 16 patientswho received no therapy.Mean EDTA chelatable Pblevels pre-chelation254.9μg/72 hrs in groupreceiving subsequent chelation279.7μg/72 hrs in controlgroupBlood Pb levels notmentioned.Rates of progression of renal insufficiency werefollowed by reciprocal of serum creatinine during the12 mos prior to therapy and for 12 mos followingtherapy. Rates of progression of renal insufficiencywere similar in the treatment group and the controlgroup during the baseline observation. However,improvement in renal function was observed duringEDTA chelation. Following chelation, renal functionstabilized in the treated group but continued to declinein the control group. At 12 mos after treatment, themean difference in the change in the reciprocal ofserum creatinine between the two groups was0.000042 L/μmol per mo (95% CI: 0.00001,0.00007). Results using a sensitivity analysis forpatients lost to follow-up (only one in each group)gave similar results.

# AX6-113Table AX6-4.3 (cont’d). Renal Effects of Lead in the Patient PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Lin et al. (2001a)TaiwanStudy date notprovided24 mo prospective observational study110 patients with CRI dichotomized by EDTA chelatablePb level of 80 μg/72 hrs into two groups of 55 each.Eligibility criteria included serum creatinine from 1.5 – 4.0mg/dL, stable renal function (decrease in GFR <5 mL/minover 6 mos); blood pressure <140/90 mm Hg; cholesterollevel <240 mg/dL; daily protein intake <1 g/kg body wt;no known history of exposure to Pb or other heavy metalsand EDTA chelatable Pb <600μg/72 h.Exclusionary criteria included potentially reversible orunstable renal disease (i.e., due to systemic diseases suchas lupus and diabetes), nephrotoxicant medications, anddrug allergies.196 patients initially screenedfor study; details on reasonsfor non-eligibility not provided.Primary outcome = 1.5 times increase in the initialcreatinine level or need fordialysis; secondary outcome =change in creatinine clearance.Cox proportional-hazards model analysis for primaryoutcome. Mean differences in creatinine clearancecompared at sequential time points with t or MannWhitney U tests.Adjustment for age, gender,baseline BMI, smoking,proteinuria, hypertension, hyperlipidemia, daily proteinintake, and underlying renal disease.Intention-to-Treat and sensitivity analyses comparedcreatinine clearance a by time period in high and low Pbgroups.Mean blood Pb levels6.6 μg/dL in high normal Pbbody burden group (n = 55)3.9 μg/dL in low normal Pbbody burden group (n = 55)Mean EDTA chelatable Pblevels pre-chelation182.9 μg/72 hrs in high normalPb body burden group (n = 55)37.9 μg/72 hrs in low normalPb body burden group(n = 55)24 mo prospective observational studyPb dose measures were only significant differencesbetween high and low normal Pb body burden groups.Of the 96 participants who completed the observationstudy, 14 patients in the high normal body Pb burdengroup reached the primary endpoint compared to 1patient in the low body Pb burden group (p < 0.001 bylog-rank test).From mo 12 to mo 24, creatinine clearance in highnormal body Pb burden patients was at leastborderline statistically lower than in low body Pbburden patients; from 18-24 mos, 95% CI excluded 0.95% CI for the difference at 24 mos was (–15.0,!3.8);difference in creatinine clearance between groups was0.15 mL/s at that point.In a Cox multivariate regression analysis, chelatablePb was significantly associated with overall risk forthe primary endpoint (RR = 41.5 [95% CI: 3.9,440.8]; p = 0.002). In this model, age, basal BMI, andbasal daily proteinuria werealso associated withincreased risk.

# AX6-114Table AX6-4.3 (cont’d). Renal Effects of Lead in the Patient PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Lin et al. (2001a)(cont’d)3 mo clinical trial of chelation with 1 yr follow-upAt 24 mos, 36 patients whose EDTA chelatable Pb levelswere 80 - 600μg/72 hrs and serum creatinine levels of<4.2 mg/dL were randomized; 24 to a 3-mo treatmentperiod consisting of weekly chelation with 1 g EDTA ivuntil their excreted Pb levels fell below 80μg/72 hrs and12 to placebo infusion.Intention-to-Treat and sensitivity analyses comparedcreatinine clearance by time period in treated and controlgroups.3 mo clinical trial of chelation with 1 yr follow-upThe two groups were similar in baseline renal riskfactors (although numbers small so beta errorpossible).Mean EDTA dose during the 3 mo period was 5 μg.After three mos of Pb chelation therapy, the body Pbburden of the patients in the chelation groupdecreased from 198 to 39.2 μg. After 3 mos ofchelation and 3 mos of follow-up, creatinine clearanceincreased by 0.08 mL/s in the treated group butdeclined by 0.04 mL/s in the controls.At the end of the study period, mean creatinineclearance was 0.68 mL/s in the chelated groupcompared to 0.48 mL/s in the control group(p < 0.05; 95% CI for the difference betweengroups = –25.0 to –0.2).

# AX6-115Table AX6-4.3 (cont’d). Renal Effects of Lead in the Patient PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Lin et al. (2001b)Study location anddate not provided;authors from Taiwan101 patients with CRI (defined as serum creatininebetween 1.5 and 3.0 mg/dL).67 with CRI and gout.34 with CRI only.Eligibility criteria included no known history of Pbexposure, certain diagnoses,and medications. CRI musthave preceded gout diagnosis.Randomized chelation trial30 participants with CRI, gout, and EDTA-chelatable Pblevels between 80.2 and 361μg/72 hrs randomized toeither a treatment group receiving 1 gram EDTA iv per wkfor 4 wks (N = 20) or to a control group who receivedglucose in normal saline iv.Mean blood Pb5.4 μg/dL (CRI and gout)4.4 μg/dL (CRI only)Mean EDTA-chelatable Pb138.1 μg/72 hrs (CRI andgout)64.2 μg/72 hrs (CRI only)(p < 0.01)In 101, EDTA-chelatable Pb higher in patients withCRI and gout compared to those with CRI only.EDTA-chelatable Pb, but not blood Pb, wasassociated positively with serum urate and negativelywith daily urate excretion, urate clearance, andfractional urate excretion.Randomized chelation trialThe two groups had similar uric acid, renal function,and Pb measures pre-chelation. In the treated group,mean EDTA-chelatable Pb declined from 159.2 to41μg/72 hrs; mean serum urate decreased from 10.2to 8.6 mg/dL (% change compared to the controlgroup =!22.4 [95% CI:!46.0,!1.5]; p = 0.02), andmean urate clearance increased from 2.7 to4.2 mL/min (% change compared to the control group= 67.9 [95% CI: 12.2, 121.2]; p < 0.01). Daily andfractional urate excretionwere also significantlydifferent between the two groups. Mean measuredcreatinine clearance increased from 50.8 to54.2 mL/min (% change compared to the controlgroup = 8.0 [95% CI:!0.4, 20.1]; p = 0.06).

# AX6-116Table AX6-4.3 (cont’d). Renal Effects of Lead in the Patient PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Lin et al. (2002)Study location anddate not provided;authors from Taiwan84 healthy participants.27 participants with gout.All with normal renal function (defined as serumcreatinine≤1.4 mg/dL).Participants with a history of occupational heavy metalexposure, EDTA-chelatable Pb levels >600μg/72 hrs, orsystemic diseases were excluded.Randomized chelation trial24 participants with EDTA-chelatable Pb levels between75 and 600μg/72 hrs randomized to either a treatmentgroup receiving 1 gram EDTA iv per wk for 4 wks(N = 12) or to a control group who received glucose innormal saline i.v.Multiple linear regression, adjustment for age, sex, BMI,daily protein intake, and creatinine clearance.Mean blood Pb3.9 μg/dL (controls)4.2 μg/dL (gout)Mean EDTA-chelatable Pb45 μg/72 hrs (controls)84 μg/72 hrs (gout)(p < 0.0001)Significantly higher mean EDTA-chelatable Pb andlower urate clearance were present in patients withgout compared to those without (3.7vs. 6.0 mL/min/1.73 m2; p < 0.001 for urate clearance).After adjustment, EDTA-chelatable Pb associatedwith all four uric acid measures (serum urate, dailyurate excretion, urate clearance, and fractional urateexcretion). Blood Pb associated with serum urate.All associations in same direction as in Lin et al.(2001).Randomized chelation trial.The two groups had similar urate, renal function, andPb measures pre-chelation. In the treated group, meanblood and EDTA-chelatable Pblevels declined (from5.0 to 3.7μg/dL and 110 to 46μg/72 hrs,respectively). Statistically significant improvementobserved in all four uratemeasures in the treatedgroup compared to the control group.

# AX6-117Table AX6-4.3 (cont’d). Renal Effects of Lead in the Patient PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Lin et al. (2003)Study location anddate not provided;authors from Taiwan24 mo prospective observational study202 patients with CRIEligibility criteria included serum creatinine from 1.5 - 3.9mg/dL, stable renal function (decrease in GFR <5 mL/minover 6 mos); blood pressure <140/90 mm Hg; cholesterollevel <240 mg/dL; daily protein intake <1 g/kg body wt;no known history of exposure to Pb or other heavy metalsand EDTA chelatable Pb <600μg/72 h.Exclusionary criteria included potentially reversible orunstable renal disease (i.e., due to systemic diseases suchas lupus and diabetes), nephrotoxicant medications, anddrug allergies.250 patients initially observed, loss due to noncomplianceor unstable renal function, baseline data on the 48 who leftor were removed from the study not provided.Cox proportional-hazards model analysis for primaryoutcome. Generalized estimating equations (GEE) forassociations between baseline chelatable Pb or blood Pblevel and longitudinal change in GFR (estimated by anMDRD equation [Levey et al.,1999]) and by measurementof creatinine clearance.Adjustment for age, gender,baseline BMI, smoking,baseline serum creatinine, proteinuria, hypertension,hyperlipidemia, daily protein intake, and underlying renaldiseases.Mean blood Pb levels5.3 μg/dL in total group(n = 202)6.1 μg/dL pre-chelation inchelated group (n = 32)5.9 μg/dL pre-chelation incontrol groupMean EDTA chelatable Pblevels pre-chelation104.5 μg/72 hrs in total group(n = 202)150.9 μg/72 hrs pre-chelationin chelated group144.5 μg/72 hrs pre-chelationin control group24 mo prospective observational studyPrimary endpoint = increase in serum creatinine to 1.5times baseline or need for hemodialysis; occurred in24 participants. Secondary endpoint = change inestimated glomerular filtration rate (GFR).In a Cox multivariate regression analysis, chelatablePb was significantly associated with overall risk forthe primary endpoint (hazard ratio for each 1μgchelatable Pb was 1.00 [95% CI: 1.00, 1.01];p = 0.03). In this model, baseline serum creatininewas also associated (hazard ratio for each 1 mg/dLwas 2.75 [95% CI: 1.46, 5.18]; p = 0.002) and, atborderline significance (p < 0.1), baseline dailyprotein excretion and smoking were as well.The association between baseline chelatable Pb andchange in GFR was modeled using GEE.Estimate =!0.003 (p = <0.001) (neither SE nor CI provided). Inthis model, gender and daily protein intake wereassociated with increased GFR; baseline serumcreatinine level, daily urinary protein excretion, andthe presence of polycystic kidney disease weresignificant predictors of a progressive decline inglomerular filtration rate.Based on this model, a 10μg higher baselinechelatable Pb level was associated with a GFRdecrease of 0.03 mL per minute per 1.73 m2of bodysurface area during the 2 yr observation period.Although statistically significant, this effect isclinically small. Furthermore, it is 40 fold lower thanthat reported in Yu et al. (2004) over a follow-upperiod that is only two-fold shorter.

# AX6-118Table AX6-4.3 (cont’d). Renal Effects of Lead in the Patient PopulationReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Lin et al. (2003)(cont’d)Study location anddate not provided;authors from Taiwan27 mo clinical trial of chelationAt 24 mos, 64 patients whose EDTA chelatable Pb levelswere 80 - 600μg/72 hrs and serum creatinine levels of<4.2 mg/dL were randomized; half to a 3-mo treatmentperiod consisting of weekly chelation with 1 g EDTA ivuntil their excreted Pb levels fell below 60μg/72 hrs andhalf to five wks of placebo infusion.Intention-to-Treat analysiscompared creatinine clearanceand GFR by time period in treated and control groups.27 mo clinical trial of chelationThe two groups were similar in baseline renal riskfactors (although numbers small so beta errorpossible).After three mos of Pb chelation therapy, the body Pbburden of the patients in the chelation groupdecreased from 150.9 to 43.2 μg and their mean bloodPb levels decreased from 6.1 to 3.9 μg/dL. GFRincreased by 3.4 mL/min/1.73 m2in the treated group;in contrast, it decreased by 1.1 mL/min/1.73 m2in thecontrol group. Mean EDTA dose during the 3 moperiod was 5.2 μg.In the subsequent 24 mos, chelation in 19 (59%)participants was repeated due to increases in serumcreatinine in associationwith rebound increases inEDTA chelatable Pb levels. Each received oneadditional chelation series (mean 4.1 g EDTA) a meanof 13.7 mos after the first chelation period. Controlpatients receiving placebo weekly for five wks everysix mos.At the end of the study period, mean estimatedglomerular filtration rate increased by 2.1mL/min/1.73 m2of body-surface area in the chelatedgroup compared to a decline of 6.0 in the controls(p < 0.01; 95% CI for the difference between groups =–11.0 to –5.1).

# AX6-119Table AX6-4.3 (cont’d). Renal Effects of Lead in the Patient PopulationReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationAsia(cont’d)Yu et al. (2004)Study location anddate not provided;authors from Taiwan121 patients followed over a four yr observationalperiod.Eligibility criteria included serum creatinine from 1.5-3.9 mg/dL, stable renal function (decrease in GFR <5mL/min over 6 mos); blood pressure <140/90 mm Hg;cholesterol level <240 mg/dL; daily protein intake <1g/kg body wt; no known history of exposure to Pb orother heavy metals and EDTA chelatable Pb <600μg/72 h.Exclusionary criteria included potentially reversible orunstable renal disease (i.e., due to systemic diseasessuch as lupus and diabetes), medical noncompliance(patients were followed for 6 mos to assesscompliance before enrollment in the study),nephrotoxicant medications, and drug allergies.Cox proportional hazards model analysis for primaryoutcomes and generalized estimating equations (GEE)for associations between baseline chelatable Pb orblood Pb level and longitudinal change in GFR(estimated by an MDRD equation [Levey et al.,1999]).Adjustment for age, gender,baseline BMI, smoking,baseline serum creatinine, proteinuria, hypertension,hyperlipidemia, daily protein intake, use of ACEinhibitor or angiotensin-receptor antagonists (sincenot all patients wereon these), and chronicglomerulonephritis (other underlying renal diseasesincluded in GEE as well).Mean (SD) blood Pb at baseline3.4 (1.3)μg/dL in 58 patientswith “low-normal” EDTAchelatable Pb levels (<80μgPb/72 hrs)4.9 (2.6)μg/dL in 63 patientswith “high-normal” EDTAchelatable Pb levels (∃80 but<600μg/72 hrs)The two groups (dichotomized bydiagnostic EDTA chelatablePb of 80μg Pb/72 hrs ) were similar inmost baseline risk factorsother than Pb body burden. Borderline statistically significant(p < 0.1) differences included mean older age in the highchelatable Pb group and certain renal diagnoses (chronicglomerulosclerosis, chronic interstitial nephritis, hypertensivenephropathy; surprisingly both ofthe latter two diagnoses wereless common in the lower Pb body burden group).Fifteen patients in the “high-normal” chelatable Pb groupreached the primary endpoint (doubling of serum creatinine overthe 4 yr study period or need for hemodialysis) compared to onlytwo in the “low-normal” group (p = 0.001 by Kaplan-Meieranalysis).In a Cox multivariate regression analysis, chelatable Pb wassignificantly associated with overall risk for the primaryendpoint (hazard ratio for each 1μg chelatable Pb was 1.01[95% CI: 1.00, 1.01]; p = 0.002).In this model, the only othervariable reaching at least borderline significance (p < 0.1) wasbaseline serum creatinine.The associations between baseline chelatable Pb or blood Pblevel and change in GFR weremodeled separately using GEE.∃=!0.1295 (p = 0.002) for Pb body burden∃=!4.0123 (p = 0.02) for blood PbBased on these models, a 10μg higher baseline chelatable Pblevel or 1μg/dL higher blood Pb level predicted 1.3 and 4.0mL/min declines in GFR, respectively, during the four yr studyperiod. Similar to the primary outcome analysis, of the manytraditional renal risk factors adjusted for in these models, onlydiagnosis of chronic interstitial nephritis was significantlyassociated, in this case with an increase in GFR. Of note,chronic interstitial nephritis wasalso a more frequent diagnosisin the group with the low-normal chelatable Pb levels (p = 0.09).The authors stated that these patients were not included in earlierpublications (which are described below in Section 6.4.4.3.3Therapeutic EDTA Chelation in Patients).

# AX6-120Table AX6-4.4. Renal Effects of Lead on MortalityReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationUnited StatesCooper (1988);Cooper et al. (1985)16 U.S. plantsEmployment between1946 and 1970;mortality from 1947to 19804519 male battery plant workers.2300 male Pb production workers.Employed for at least one yr between 1946 and 1970.Cause of death per death certificate (extrapolated whenmissing).Standardized mortality ratios (SMRs) compared withnational age-specific rates. PMR also assessed.Analyzed separately by battery and Pb production, by hiredate before and after 1/1/1946, and by cumulative yrs ofemployment (1-9, 10-19, 20+).Mean blood Pb63 μg/dL in n = 1326 batteryworkers80 μg/dL in n = 537production workersPast Pb exposures poorlydocumented prior to 1960Follow-up >90% in both groups; 2339 deathsobserved.“Chronic or unspecified nephritis” SMR:222 (95% CI: 135, 343) in battery workers265 (95% CI: 114, 522) in Pb production workers“Other hypertensive disease” SMR (“includes HTNand related renal disease without mention of heartdisease)”:320 (95% CI: 197, 489) in battery workers475 (95% CI: 218, 902) in Pb production workersRace adjusted proportionatemortality ratios analysessimilar.Nephritis deaths observed primarily in workers hiredbefore 1946.Limitations = due to mortality analysis (inaccuraciesof death certificates, exposure assessment generallylimited).Steenland et al. (1992)IdahoEmployed between1940 and 1965;mortality up to 19881990 male Pb smelter workers.Employed in a Pb-exposed department for at least one yrbetween 1940 and 1965.Vital status was determined using records from the SocialSecurity Administration andthe National Death Index.Mean blood Pb56.3 μg/dL (n = 173, measuredin 1976)High Pb exposure defined asworkers from departmentswith an avg >0.2 mg/m3airborne Pb or∃50% of jobshad avg levels more than twicethat level (1975 survey). Inthis category, n = 1,436.Compared to the U.S. white male population, thestandardized mortality ratio (SMR) for chronic kidneydisease, based on only 8 deaths, was 1.26 (95%CI = 0.54, 2.49). SMR = 1.55 in high Pb exposuregroup, also not significant. The SMR for chronickidney disease increased with duration of exposurefrom 0.79 in workers exposed 1-5 yrs to 2.79 inworkers exposed >20 yrs; however SMR was notsignificant.

# AX6-121Table AX6-4.4 (cont’d). Renal Effects of Lead on MortalityReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationEuropeFanning (1988)UKDeaths from1926-1985Deceased males identified through pension records of Pbbattery and other factory workers.867 deaths of mean with high Pb exposure compared to1206 men with low or no Pb exposure.Range of blood Pb40-80 μg/dL since ~1968 inhigh Pb exposure group;thought not to have hadclinical Pb poisoning due tomedical surveillance.<40 μg/dL since ~1968 in littleor no exposure group.Odds ratio for renal disease = 0.62, not significant,based on only 11 deaths. Similar for diagnosis ofnephritis. Possible decreasing odds ratio over time ofdeaths with mention of nephritis on death certificatebut not significant and numbers still quite small.Limitations = standardmortality study issuesalthough deaths compared with other workers and notgeneral population which is a strength in this type ofstudy.

# AX6-122Table AX6-4.5. Renal Effects of Lead in ChildrenReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationUnited StatesHu (1991)U.S.Study date notprovided21 of 192 adults who werehospitalized at BostonChildren’s Hospital between 1932 to 1942 for childhoodPb poisoning were traced to a Boston area address.Matched on age, sex, race, and neighborhood to21controls.Mean (SD) blood Pb6.0 μg/dL (Pb poisoned)7.5 μg/dL (controls)No significant differencesin blood Pb level, serumcreatinine, or BUN. Mean measured creatinineclearance higher in the previously Pb poisoned groupcompared to controls (112.8 vs. 88.8 mL/min/1.73 m2[p < 0.01]). Mean in the Pb exposed group was alsohigher than the predicted value of 94.2 mL/min/1.73m2from the nomogram of Rowe et al. (1976).Suggests Pb-related hyperfiltration. As noted insection 6.4, one survivor, identified but not includedin the study, had disease consistent with Pbnephropathy.Limitations = small study size and concern forsurvivor bias in the study group.Loghman-Adham(1998)Chicago, ILStudy date notprovided134 children and young adults, 8 to 13 yrs after chelationtherapy for severe Pb poisoning.Mean age at poisoning = 2.3 yrsMean age at follow-up = 13.4 yrsMean peak blood Pb level121 μg/dLMean blood Pb level at timeof study18.6 μg/dLMean serum creatinine was normal (0.8 mg/dL).Calculated creatinine clearance normal in all but 3children. No correlation between either initial orcurrent blood Pb and serum creatinine or calculatedcreatinine clearance.Urinaryα-amino nitrogen concentrations weresignificantly increased compared with 19 healthy agematched controls and were correlated with currentblood Pb levels. Thirty-two children (24%) hadglycosuria. Fractionalexcretion of phosphate,however, was normal in all children. The authorconcluded that a partial Fanconi syndrome couldpersist for up to 13 yrs after childhood Pb poisoning.The author notes that the prognostic significance ofthis is unknown at present.

# AX6-123Table AX6-4.5 (cont’d). Renal Effects of Lead in ChildrenReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationEuropeMcDonald and Potter(1996)Boston, MA1991454 pediatric hospital patientswho were diagnosed withPb poisoning between 1923 and 1966 were tracedthrough 1991.Mortality study, comparison with U.S. population.Chronic nephritis was not a significant cause of death.Mortality from all cardiovascular disease waselevated (observed/expected = 2.1 [95% CI: 1.3,3.2]) and cerebral vasculardeaths were particularlycommon among women (observed/expected = 5.5[95% CI: 1.1, 15.9]).Moel and Sachs (1992)Chicago, IL1974-198962 participants with blood Pb>100 μg/dL, diagnosed andchelated between 1966 and 1972, together with 19 age-matched control siblings with initial blood Pbs less than40 μg/dL. Mean age at follow-up = 22 yrs.Renal outcomes = serum creatinine, uric acid, and∃2-microglobulin, fractional excretion of∃2-microglobulin,urinary protein:creatinine ratio, and tubular reabsorptionof phosphate.Mean initial blood Pb150.3 μg/dL (highly poisonedas children)Data for siblings not availableas levels <40 μg/dL notquantified.There were no statistical differences in either renalfunction or blood pressure between study subjects andcontrol siblings. Initial blood Pb level was notassociated with serum creatinine, after adjustment forage, gender, and body mass index. A modest increasein serum creatinine values was observed over a nine-yr period in four of the 62 study subjects (up to1.6 mg/dL).Bernard et al. (1995b)Czech RepublicStudy date notprovided144 children living close to a Pb smelter (exposed groups1 and 2).51 controls living in a rural area presumed to berelatively unpolluted with Pb.Mean age = 13.5 yrs.Renal outcome measures included urinary albumin, RBP,NAG, Clara cell protein, and∃2-microglobulin.Retinol binding protein73.8 μg/g creatinine (controls)109.4 μg/g creatinine (exposed group 1)117.8 μg/g creatinine (exposed group 2)∃2-microglobulin60.3 μg/g creatinine (controls)89.1 μg/g creatinine (exposed group 1)66.4 μg/g creatinine (exposed group 2)NAG1.56 IU/g creatinine (controls)2.32 IU/g creatinine (exposed group 1)1.46 IU/g creatinine (exposed group 2)Multiple linear adjusting for age and gender.Blood Pb8.7 μg/dL (control boys)8.39 μg/dL (control girls)10.9 μg/dL (exposed boys 1)9.4 μg/dL (exposed girls 1)14.9 μg/dL (exposed boys 2)12.9 μg/dL (exposed girls 2)Mean blood Pb levels significantly higher in bothexposed groups compared to the control group. Incontrast, blood cadmium levels were similar amongall groups. After adjustment for age, sex, bloodcadmium, and zinc protoporphyrin, log transformedblood Pb was associated with log transformed RBP(∃= 0.302, p = 0.005).

# AX6-124Table AX6-4.5 (cont’d). Renal Effects of Lead in ChildrenReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationEurope(cont’d)De Burbure et al.(2006)France, the CzechRepublic, and PolandStudy date notprovided804 exposed and control children.Exposed children recruited from residents near historicalnonferrous smelters, must have lived∃8 yrs nearsmelters.Mean age = 10 yrs; range = 8.5-12.3 yrs.Renal outcome measures included serum creatinine,cystatin C and ß2-microglobulin as well as urinary RBP,NAG, Clara cell protein.Mean blood PbRanged from 2.8 to 4.2 mg/dLin various control and exposedgroups.Urinary cadmium, arsenic andmercury as well as bloodcadmium also assessed.Serum concentrations of creatinine, cystatin C, andß2-microglobulin negatively correlated with blood Pblevels.Authors state suggestive of an early renalhyperfiltration that avgd 7% in the upper quartile ofPbB levels (>5.5 μg/dL; mean 7.84 μg/dL).Factor-Litvak et al.(1999)Kosovo, Yugoslavia1985-1993577 children followed at 6 mo intervals through 7.5 yrsof age.Divided into a high exposure and a low exposure group,based on residence in Kosovska Mitrovica with a Pbsmelter, refinery, and battery plant or in Pristina, 25 milesaway.Renal outcome = Proteinuria assessed with a dipstick.Multiple logistic regression modeling of proteinuriadichotomized as either any or none, adjusting forsocioeconomic status, maternal education/ intelligence,and quality of childrearing environment.Mead blood Pb from graphpeaked at ~38 μg/dL betweenages 3-5 in KosovskaMitrovica and at ~10 μg/dL incontrols.Blood Pb level ranged from1 to 70 μg/dL.In higher exposed group, adjusted OR for proteinuriawas 3.5 (95% CI: 1.7, 7.2); adjusted odds ofproteinuria increased by 1.15 (95% CI: 1.1, 1.2) perunit increase in blood Pb in the higher exposed group.Proteinuria unrelated to blood Pb in lower exposedcontrol group.Limitations = limited renal outcomes assessed, highdropout rate in the study.

# AX6-125Table AX6-4.5 (cont’d). Renal Effects of Lead in ChildrenReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationEurope(cont’d)Fels et al. (1998)Poland1995112 children (50 controls, 62 exposed).Mean age = 9.9 yrs and 10.6 yrs in controls and exposedgroup, respectively.Numerous (29) renal outcome measures were examinedincluding serum creatinine and∃2-microglobulin, andurinary NAG, RBP, Clara cell protein,∃2-microglobulin,6-keto-prostaglandin F1α(6-keto-PGF1α), prostaglandinE2(PGE2) and thromboxane B2(TXB2).Urinary RBP46 μg/g creatinine (exposed)42 μg/g creatinine (controls)Urinary∃2-microglobulin89 μg/g creatinine (exposed)37 μg/g creatinine (controls)Serum creatinine0.63 mg/dL (exposed)0.63 mg/dL (controls)Mean blood Pb13.3 μg/dL (exposed)3.9 μg/dL (controls)Significantly higher mean serum∃2-microglobulin,and urinary transferrin, 6-keto-PGF1α, thromboxaneB2, epidermal growth factor,∃2-microglobulin, PGE2,and Clara cell protein in the exposed children. Incontrast, NAG-B was lower in the exposed group.Categorical blood Pb associated with prevalence ofvalues above the upper reference limits for severalbiomarkers. Urinary 6-keto-PGF1α, TXB2,∃2-microglobulin, Clara cell protein, epidermal growthfactor and PGE2positively correlated with blood Pb(r = 0.441, 0.225, 0.203, 0.261, 0.356, and 0.23,respectively; all with significant p-values).Limitations = data analysis, limited adjustment._ktem et al. (2004)TurkeyStudy date notprovided79 adolescent auto repair workers (mean age 17.3 yrs).71 rural adolescents as negative controls (mean age 17.0yrs).Renal outcomes = urinary NAG,∃2-microglobulin, uricacid, and calcium; blood urea nitrogen (BUN), serumcreatinine and uric acid.Mean blood Pb7.79 μg/dL (exposed workers)1.6 μg/dL (controls)No difference in mean BUN, serum creatinine, uricacid, or GFR (apparently estimated) between workersand controls.Urinary NAG and calcium significantly higher inworkers compared to controls. Urinary NAGpositively correlated blood Pb (r = 0.427).Limitations = data analysis, lack of adjustment.

# AX6-126Table AX6-4.5 (cont’d). Renal Effects of Lead in ChildrenReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationEurope(cont’d)Price et al. (1999)Belgium, Poland,Germany and ItalyStudy date notprovidedUrinary Pb measured in 481 European children (236controls, 245 exposed) aged 6 – 14 yrs.Several renal outcome measures assessed includingurinary NAG and∃2-microglobulin; values not reported.Mean urinary PbRange from 3.9 to 7.2 μg/gcreatinine (controls)Range from 5.2 to 24.6 μg/gcreatinine (exposed)Urinary Pb generally higherin exposed children ascompared to controls. Authors unexpectedly foundsubstantial differences inrenal biomarkers by studysite. Authors note several renal biomarkers differedbetween exposed and control groups. Alsoquestioned the use of “control” groups in ubiquitousexposures.Sch≅rer et al. (1991)Germany1988-198922 children, age 5-14 yrs, with CRI.20 siblings or neighbors as lower exposed group.16 control children without known Pb exposure.Mean blood Pb2.9 μg/dL in children withCRI, not tested in other groupsMean dental Pb content2.8 μg/g in children with CRI1.7 μg/g in sibs/neighbors1.4 μg/g in controlsPb levels in teeth significantly higher in both thepatient and sibling/neighbor control groups comparedto the unexposed control group.S⎯nmez et al. (2002)TurkeyStudy date notprovided39 adolescent auto repair workers (mean age 16.2 yrs).13 adult battery workers as positive controls (mean age32 yrs).29 rural adolescents as negative controls (mean age14.8 yrs).Serum creatinine0.99 mg/dL (exposed group)0.99 mg/dL (positive/ adult controls)0.89 mg/dL (negative/ adolescent controls)Urinary NAG4.7 IU/g creatinine (exposed group)7.4 IU/g creatinine (positive/ adult controls)3.1 IU/g creatinine (negative/ adolescent controls)Mean blood Pb8.13 μg/dL (exposed group)25.3 μg/dL(positive/adult controls)3.49 μg/dL(negative/ adolescent controls)All participants had normal blood urea, creatinine,and uric acid levels as well as normal routineurinalysis.Blood Pb level and urinaryNAG significantly higherin adolescent auto repair workers compared to thenegative control group.Limitations = data analysis, lack of adjustment.

# AX6-127Table AX6-4.5 (cont’d). Renal Effects of Lead in ChildrenReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationEurope(cont’d)Staessen et al. (2001)Belgium1999100 exposed and 100 control children.Mean age = 17 yrs.Two exposed groups were recruited from industrializedsuburbs while the control group was recruited from a ruralarea.∃2-microglobulin5.22 μg/mmol creatinine (controls)5.3 μg/mmol creatinine (exposed group 1)9.09 μg/mmol creatinine (exposed group 2)Cystatin-C0.65 mg/L (controls)0.63 mg/L (exposed group 1)0.71 mg/L (exposed group 2)Multiple linear regression adjusting for sex and smokingstatus.Mean blood Pb1.5 μg/dL (controls)1.8 μg/dL (exposed group 1)2.7 μg/dL (exposed group 2)Blood Pb,∃2-microglobulin, and Cystatin-C levelshigher in exposed group 2 as compared to controls andexposed group 1.After adjustment for sex and smoking status, blood Pbwas associated with both∃2-microglobulin andcystatin-C. A two-fold increase in blood Pb wasassociated with a 3.6% (95%CI: 1.5, 5.7) increase inCystatin-C and a 16% (95% CI: 2.7, 31) increase in∃2-microglobulin. Blood cadmium was not associatedwith either outcome.Verberk et al. (1996)Romania1991-1992151 children who resided at different distances from a Pbsmelter.Mean age = 4.6 yrs.Renal outcomes = urinary RBP, NAG,α1-microglobulin,albumin and alanine aminopeptidase.Geometric meansUrinary RBP49.4 μg/g creatinineUrinary NAG6.9 U/g creatinineUrinaryα1-microglobulin2.4 mg/g creatinineUrinary alanine aminopeptidase19.8 U/g creatinineMultiple regression analysis adjusting for age and gender.Mean (SD) blood Pb34.2 (22.4) μg/dLAfter adjustment for age and gender, a 10 μg/dLincrease in blood Pb was associated with a 13.5%increase in NAG excretion (90% CI: 10.2, 17).No threshold was observed. No other significantassociations noted.

# AX6-128Table AX6-4.5 (cont’d). Renal Effects of Lead in ChildrenReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationAfricaDiouf et al. (2003)Senegal199838 Senegalese children (19 exposed, 19 controls).Age range = 8 – 12 yrs old.Renal function assessed by measuring urinary alpha-glutathione S-transferase (αGST).Mean (SD) blood Pb10.7 (1.7) μg/dL (exposed)6.1 (1.8) μg/dL (controls)Blood Pb significantly higher in exposed group (urbandwellers) as compared tocontrols (rural dwellers).Unclear as to whetherαGST was higher or lower incontrols as compared to exposed group (stated to behigher in controls in the results section BUT stated to behigher in the exposed group in the discussion).Regardless, the difference was not statisticallysignificant.Limitations = small sample size, data analysis.

# AX6-129 

# ANNEX TABLES AX6-5

# AX6-130Table AX6-5.1. Effects of Lead onBlood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationMeta-analysisNawrot et al. (2002)31 U.S. and Europeanstudies, communityand occupationallyexposed, publishedbetween 1981 and2001.48 different groups, 32 of whichwere only of men, 15 of which wereonly of women, and one studyingboth sexes. Total meta-analysisN > 58,490. Age ranged from 15 to93 yrs, depending on the study.Two methods of meta-analysis wereused, subject-weighted and non-weighted, using study-reportedeffect sizes and standard errors,transformed from the original studyspecification of blood Pb (linear,logarithmic, or blood Pb group) to asingle effect size for doubling ofblood Pb. Also did analysesstratified by race and sex.Mean blood Pb concentrationacross studies ranged from2.3 to 63.8 μg/dL. Totalrange of blood Pb acrossstudies was 0 to 97.9 μg/dL.Each doubling of blood Pb was associated with a significant 1.0 mm Hg(95% CI: 0.5, 1.4) increase in systolic blood pressure and a significant 0.6mm Hg (95% CI: 0.4, 0.8) increase in diastolic blood pressure. Stated thatdifferences in Pb effect were not statistically different between sexes, but didnot describe test nor givestatistics other than p-values. Presented black andwhite differences as a trend for blacks to be “more susceptible than whites,”but presented no tests.Statistically examined assumptionsof homogeneity of effect and found nosignificant heterogeneity. Tested for publication bias (statistically significantresults tend to be published more than non-significant results) and found noevidence. Found no significant effects of removing one study at a time insensitivity analysis. It appears that the presented results of effect sizes andconfidence intervals were calculated bythe subject-weightedmethod, but thiswas not made explicit. Included some studies that presented no Pbcoefficients or standard errors, assuming effect size of zero, though thereported effect sizes without these studies did not appear to be different fromoverall effect sizes. For studies using a linear Pb measure, effect sizes werecalculated by doubling the arithmetic mean blood Pb. If the concentrationresponse curve for the Pb-blood pressurerelationship was really bettercharacterized by a log-linear function, the authors’ use of studies with a linearblood Pb term with high avg blood Pb led to over-estimation of the slope ofthe relationship and those studies withlow blood Pb avgs produced an underestimation of the slope of the relationship.

# AX6-131Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited StatesCheng et al. (2001)U.S.-Boston,Normative AgingStudy (VA)1991-1997833 males (~97% white), avg age(SD):65.5 (7.2) Normotensive subjects,N = 33768.3 (7.8) Borderline hypertensivesubjects, N = 18167.9 (6.8) Definite hypertensivesubjects, N = 314474 males with no history ofhypertension at first measurement,returning up to 6 yrs later forhypertension study.Linear multiple regression models ofblood pressure and Cox proportionalhazard models of new cases ofhypertension after up to 7 yrs, withone group of covariates forced intomodels based on biologicalplausibility and another groupforced based on significantunivariate or bivariate results or>20% effect modification of Pbvariable coefficient in multiplemodels. Linear blood Pb, tibia Pb,and patella Pb forced in separatemodels.Arithmetic mean (SD) bloodPb:5.9-6.4 μg/dL (3.7-4.2),depending on hypertensiongroup (only data shown).Multiple regression models of blood pressure always included age, agesquared, BMI, family history of hypertension, daily alcohol consumption,and daily calcium consumption. Increasing tibia Pb concentration wasassociated with increased systolic bloodpressure (diastolic not addressed) inbaseline measurements insubjects (n = 519) free from definite hypertension(systolic >160 mm Hg, diastolic >95 mmHg, or taking daily antihypertensivemedication). Each increase of 10 μg/g tibia Pb concentration was associatedwith an increase in systolic blood pressure of 1.0 mm Hg (95% CI: 0.01,1.99). Patella and linear blood Pb were not significant.Cox proportional hazard models always included age, age-squared, BMI, andfamily history of hypertension. In follow up (n = 474), only increasingpatella Pb predicted increasing risk of definite hypertension in thoseclassified as normotensive at baseline. For every 10 μg/g increase in patellaPb risk ratio increased 1.14 (95% CI: 1.02, 1.28). Combining borderlinehypertension (systolic 141-160 mm Hg or diastolic 91-95 mm Hg) withdefinite hypertension (n = 306), the relative risk ratio of becoming acombined hypertensive associated with a 10 μg/g increase in patella Pb was1.23 (95% CI: 1.03, 1.48). Linear blood Pb and tibia Pb were notsignificant.Linear blood Pb is not indicated for blood pressure models due to stronglikelihood of significant residual heteroscedasticity and non-normality.Relatively small sample size may haveprevented tibia blood Pb significancein the Cox proportional hazard models.

# AX6-132Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Den Hond et al.(2002)U.S.-NHANES III1988-19944,685 white males, 5,138 whitefemales, 1,761 black males, 2,197black females, from 20 yrs up. Log-transformed blood Pb, systolic anddiastolic blood pressure measured atsurvey time and analyzed withforward, stepwise multipleregression with covariates.Avg age:WhiteMale: 44.3 yrsFemale: 46.2 yrsBlackMale: 40.5 yrsFemale: 41.5 yrsGeometric mean(25th-75th percentile)blood Pb:White male mean 3.6 μg/dL(2.3-5.3)White female mean 2.1 μg/dL(1.3-3.4)Black male mean 4.2 μg/dL(2.7-6.5)Black female mean 2.3 μg/dL(1.4-3.9)After adjusting for age, age-squared, BMI, hematocrit, smoking, alcohol, and anindicator variable for use of antihypertensive medications, each model wasfurther modified by a unique mix ofother covariates, including: coffeeconsumption, dietary calcium, dietary sodium/calcium ration, total serumprotein, total serum calcium, diabetes, and poverty index. Log Pb was forced inlast.In stratified analyses, only blacks had significant positive blood pressureassociations with log blood Pb. Each doubling of blood Pb was associated withincrease of black male systolic blood pressure of 0.9 mm Hg (95% CI: 0.04,1.8), black female systolicblood pressure of 1.2 mm Hg (95% CI: 0.4, 2.0), andfemale diastolic blood pressure of 0.5 mmHg (95% CI: 0.01, 1.1). In whitemales only, each doubling of blood Pb was significantly associated with adecrease in diastolic blood pressure of -0.6 mm Hg (95% CI:−0.9,−0.3).Stepwise models can rely on chance associations due to multiple testing andusually lead to a different pattern of covariate adjustment in different models.Inclusion of likely confounding variables such as serum calcium could haveaffected estimated Pb effects. No testing for significant Pb coefficientdifferences between each stratum. Nomodel diagnostic tests reported. Noexplanation offered for inverse relationship between Pb and diastolic bloodpressure in white males. No adjustment for survey design.Gerr et al. (2002)U.S.-Spokane WAand area aroundSilver Valley ID1994502 young people, age 19-29 yrs,53% female, nearly evenly dividedinto the Spokane group (no unusualchildhood exposure) and the SilverValley group, where a Pb smelteroperated during their childhood.Multiple regression models ofsystolic blood pressure and diastolicblood pressure. All covariatesforced into model as block with bothlinear blood Pb and tibia bone Pb ineach model.Mean (SD) blood Pb onlygiven stratified on tibia Pbcategory:Tibia <1 μg/g: 1.9 μg/dL(1.6)Tibia 1-5 μg/g: 2.3 μg/dL(2.1)Tibia 6-10 μg/g: 2.4 μg/dL(2.4)Tibia <10 μg/g: 3.2 μg/dL(2.3)No other descriptive tibia Pbdata given.Adjusting for sex, age, height, BMI, education, income, current smoker, currentalcohol use, childhood residence (the two recruitment areas), current birthcontrol pills, hemoglobin,and serum albumin, only tibia Pb, and not linear bloodPb, was significantly related to systolicand diastolic blood pressure. Comparedto the <1 μg/g tibia Pb category,subjects in the >10 μg/g category had4.3 mm Hg (95% CI: 1.4, 6.7) highersystolic blood pressure and 2.8 mm Hg(95% CI: 0.4, 5.2) higher diastolic blood pressure.Linear blood Pb is not indicated for blood Pb-blood pressure models.No diagnostic testing reported. Insufficient descriptive data given for tibia Pb.

# AX6-133Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Glenn et al. (2003)U.S.-New Jersey1994-1998496 males, mean (SD, range) age55.8 (7.4, 40-71) yrs, working orformerly working at a plantproducing tetraethyl or tetramethylPb until 1991, were followed from10 mos to 3.5 yrs during whichblood pressure was repeatedlytested. Blood Pb was tested only atbaseline. Tibia Pb was tested in1991 (at the end of organic Pbproduction at the plant) and called“peak tibia Pb” and again during1997 (yr 3). Generalized estimatingequations with an exchangeablecorrelation structure for repeatedmeasurements were used for systolicand diastolic blood pressure. Onegroup of covariates was forced intothe model as a block (age atbaseline, race, BMI, indicatorvariable for technician, Pb variable(linear blood Pb, peak tibia Pb, andtibia Pb each tested separately),duration of follow up, and theinteraction between the Pb variableand the duration term. Potentialconfounding variables were enteredstepwise and retained in the model ifsignificant. Alternate models notusing linear time were constructed,using quartile of follow up time toavoid assuming a linear relationshipof change in blood pressure withtime.Arithmetic mean (SD, range)blood Pb at baseline:4.6 μg/dL (2.6,!1 to 20)Tibia Pb at yr 3:14.7 μg/g (9.4,!1.6 to 52)Peak tibia Pb:24.3 μg/g (18.1,!2.2 to118.8)Controlling for baseline age, BMI, antihypertensive medication use, smoking,education, technician and number of yrs to each blood pressure measurement,each 1 μg/dL increase in linear baseline blood Pb was associated with avgsystolic blood pressure increase of 0.64 mm Hg/yr (95% CI: 0.14, 1.14),each 10 μg/g increase in yr 3 tibia Pb with an avg increase of 0.73 mm Hg/yr(95% CI: 0.23, 1.23), and each increase of10 μg/g of peak tibia Pb with anavg increase of 0.61 mm Hg/yr (95% CI: 0.09, 1.13). Similar results wereobtained using the follow up time quartile designation for systolic bloodpressure with all subjects and withsubjects not taking antihypertensivemedications.This was one of the few studies usinga prospective design and that used astatistical technique accounting for repeated measures. No justification givenfor using an exchangeable correlation structure instead of an alternate one.Only examined cortical bonePb (tibia) and not trabecular bone Pb (patella orcalcaneus). Linear blood Pb may not be indicated for use in blood Pb-bloodpressure models. Stepwise modeling involves multiple testing of the samedata set with no control for altered probabilities. Nomodel diagnosticspresented.

# AX6-134Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Glenn et al.(2001)U.S.-New Jersey1996-1997213 males (92% white), mean (SD)age 58.0 (7.4) yrs, working orformerly working at a plantproducing tetraethyl or tetramethylPb until 1991, were genotyped forATP1A2(5’) and ATP1A2(3’)polymorphism. ATPase is thought toplay a role in regulating bloodpressure and Pb inhibits its activity.Blood pressure, blood Pb, and tibiaPb were measured. Multiple linearregression models were used forsystolic and diastolic blood pressure.Logistic regression model wasreported for hypertension(systolic >160 mm Hg,diastolic >96 mm Hg, or takingantihypertensive medications).Covariate entry methods notspecified, but were likely stepwise.Covariates for the blood pressuremodel were age, use ofantihypertensive medications,alcohol, smoking, season of yr, linearblood Pb, tibia Pb (the two Pbmeasures apparently testedseparately), ATP1A2(5’) andATP1A2(3’) polymorphism (eachtested separately), and an interactionterm between polymorphism and Pb.Covariates for the hypertensionmodels were age, BMI, lifetimealcoholic drinks, linear blood Pb andtibia Pb, and polymorphism, each Pbmeasure and polymorphism testedseparately.Arithmetic mean (SD, range)blood Pb:5.2 μg/dL (3.1, 1-20)Mean (SD) tibia Pb:16.3 μg/g (9.3)None of the relationships between theATP1A2(5’) polymorphism and either bloodor bone Pb or blood pressure were significant.The ATP1A2(3’) polymorphism was homogenous for the 10.5 kilobase allele(10.5/10.5) in 11 subjects, heterogeneousfor the 10.5 and 4.3 kilobase allele(10.5/4.3) in 82 subjects, and heterogeneous(10.5/4.3) in 116 subjects. Prevalenceof the 10.5 allele was significantlyhigher in blacks than in whites.Regression coefficients of 4.3/4.3 and 10.5/4.3 genotypes were not significantlydifferent and all subsequent analyses compared the 10.5/10.5 genotype with thecombined 4.3/4.3-10.5/4.3) genotype. The significant interaction between linearblood Pb and the 10.5/10.5 genotype showed that for every 1 μg/dL of blood Pbsystolic blood pressure increased 5.6 mm Hg (95% CI: 1.2, 9.9) more than the bloodpressure of the combined genotype group. Blood Pb range of the combinedgenotype group was twice that of the 10.5/10.5 group. When data were truncated tomake blood Pb of both groups cover the samerange, coefficients of the genotypelinear blood Pb interaction term did not change appreciably. Authors state that tibiaPb interacted with genotype on blood pressurebut showed no data to estimate eithertype or size of effect. Diastolic blood pressure was not related to genotype, to Pb orto the interaction between Pb and genotype.Prevalence of hypertension (30% in total sample) was significantly higher amongthe 10.5/10.5 group (63.4 %) than among the combined group (28.3 %). Adjustingfor age, BMI, and lifetime alcohol, the oddsof hypertension in the 10.5/10.5 groupwere OR = 7.7 (95% CI: 1.9, 31.4) compared to the 4.3/4.3 group. Theheterogeneous group was not significantly different from the 4.3/4.3 group.Linear blood Pb specification not indicated for blood Pb-blood pressure modeling.Examination of partial residual plot forsystolic blood pressure and linear blood Pbshows typical heterogeneity ofresiduals as a function of predicted values. Thus,presented coefficients may be inefficient and biased. Only 9 subjects werehomogenous for 10.5/10.5 in the multiple regression model. Only cortical bone Pbwas tested, not trabecular bone Pb. Cortical bone Pb models not shown orquantitatively described. Blood Pb roundedto nearest unit μg/dL. Mixed organicinorganic Pb exposure. Relatively small sample size may have prevented detectionof other significant effects.No model diagnostics described.

# AX6-135Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference,StudyLocation, andPeriodStudy Description Pb Measurement Findings, InterpretationUnited States(cont’d)Hu et al. (1996)U.S.-Boston-NormativeAging Study-VA1991-1994590 males (over 98% white), mean agearound 67 yrs, divided into 146hypertensives (systolic >160 mm Hg,diastolic >95 mm Hg, or dailyantihypertensive medication) and 444 non-hypertensives. Linear blood Pb, tibia andpatella bone Pb added separately to logisticregression model containing forcedcovariates of age, race, BMI, family historyof hypertension, pack-yrs smoking, alcoholingestion dietary sodiumand calcium. Then,a backward elimination procedure startingwith all covariates, including all Pbvariables, resulted in a model in which onlysignificant covariates were retained.Hypertensives:Arithmetic mean (SD)blood Pb:6.9 μg/dL (4.3)Mean tibia Pb:23.7 μg/g (14.0)Mean patella Pb:35.1 μg/g (19.5)Non-hypertensives:Arithmetic mean (SD)blood Pb:6.1 μg/dL (4.0)Mean tibia Pb:20.9 μg/g (11.4)Mean patella Pb:31.1 μg/g (18.3)Logistic regression model withall forced covariates revealed no significant Pbeffects when the three Pb variables were forced into the model separately. Afterbackward elimination, the only significantcovariates left were BMI and familyhistory of hypertension. Of all the Pb variables, only tibia Pb remained in themodel. With each increase of 10 μg/gof tibia Pb, odds of being classifiedhypertensive rose (OR = 1.21; 95% CI: 1.04, 1.43).Stepwise regression, backward or forward,involves multiple testing with the samedata set, capitalizes on chance occurrencein the data set, and gives over-optimisticprobability values. No model diagnostic testing reported.

# AX6-136Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Korrick et al.(1999)U.S.-Boston-NurseHealth Study1993-1995284 women, from 47-74 yrs, mean age(SD) 58.7 (7.2), were divided into 97cases (systolic∃140 mm Hg,diastolic∃90 mm Hg, or physician-diagnosed hypertension) and195 controls. Controls were furtherclassified as low normal(<121/75 mm Hg) and high normal>121/75 mm Hg). Three ordinalregression models were constructed,each containing either blood Pb, tibia Pbor patella Pb with forced entry of allother covariates. A final backwardselimination ordinal regression modelstarted with all covariates, including allPb variables, excluding each until onlysignificant variables were left.Interactions were tested in the finalmodel between patellaPb and alcoholuse, age, and menopausal status.Mean blood Pb (SD, range):3.1 μg/dL (2.3, <1 to 14)Mean tibia Pb (SD, range):13.3 μg/g (9.0,!5 to 69)Mean patella Pb (SD, range):17.3 μg/g (11.1,!5 to 87)Only patella Pb was significantly related to increased odds of hypertensionin the preliminary models, adjusted for age, BMI,alcohol, dietary calciumand sodium, ever smoke, and family hypertension. Each 10 μg/g increase inpatella Pb was associated with increased odds of hypertension OR = 1.28(95% CI: 1.03, 1.60). In the backwardelimination model adjusted for age,BMI dietary sodium and family hypertension, only natural log transformedpatella Pb remained in the model. Identical odds ratios from patella Pb wereobtained in both models. None of the interaction tests were significant.Small study size may have limited power to detect significant interactions.The proportional odds assumption ofthe ordinal regression model wasverified. Note that the odds ratios above are for movement from one of thetwo lower categories, low normal andhigh normal, to the next highercategory as patella Pb increased. No other model diagnostic tests reported.Morris et al. (1990)U.S.-sampled fromgeneral populationaround Portland,OR responding toads to participate inclinical trials ofnonpharmacologicalmanagement ofblood pressure.1984-1989?145 males and 106 females, 73% witharterial pressures >105 mm Hg,provided blood pressure measurementsonce a wk over four consecutive wks.Blood for Pb analysis was collectedduring this period. Stepwise multipleregression was used to constructseparate models of systolic and diastolicblood pressure stratified by sex.Covariates availableto be entered wereage, BMI, dietary calcium and “othernutrient intakes,” ionized serumcalcium, erythrocyte protoporphyrin andnatural log transformed blood Pb.Arithmetic mean (SD) bloodPb:Males: 8.0 μg/dL (4.4)Females: 6.9 μg/dL (3.6)Natural log blood Pb wasonly a significant predictor of blood pressure inmales. Adjusting for age and ionized serum calcium, every one natural unitincrease in blood Pb was significantly associated with a 4.58 mm Hg(neither SE nor CI stated) in systolic blood pressure and, adjusting forhemoglobin, age, and current smoking, a 1.90 mm Hg (neither SE nor CIstated) in diastolic blood pressure.The usual precautions regarding multiple testing and different covariatepatterns in stratified models constructed with stepwise regression apply.Reporting of effects not complete. Small sample size limits conclusionsabout non-significant effects. High prevalence of hypertensives in sampledue to study recruitment design. Blood Pb technique, as represented bypresented graph, had a detection limitof 5 μg/dL. No model diagnostics.

# AX6-137Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Nash et al. (2003)U.S.-NHANES III1988-19941084 premenopausal and 633postmenopausal women, from 40to 59 yrs. Multiple linearregression models withcovariates, including linear bloodPb, entered as a block for systolicand diastolic blood pressure.Logistic regression models withsame covariates and Pb quartileadded last for hypertension.Mean (range) blood Pb byPb quartile:1st quartile 1.0 μg/dL(0.5-1.6)2nd quartile 2.1 μg/dL(1.7-2.5)3rd quartile 3.2 μg/dL(2.6-3.9)4th quartile 6.4 μg/dL(4.0-31.1)Linear blood Pb was entered last after forcing in age, race/ethnicity, alcohol use,cigarette smoking, BMI, and kidney function (serum creatinine) in multiple regressionmodels for all women and women stratifiedby menopause status for systolic anddiastolic blood pressure. Pb quartile wasadded to logistic regression models ofhypertension (systolic∃140 mm Hg, diastolic∃90 mm Hg or taking antihypertensivemedication with the same covariates as the blood pressure models, in all women andstratified by menopausal status. Tested additional models in which women treated forhypertension were excluded from models.All models were adjusted for sampledesign and weighting.Each increase of 1 μg/dL of blood Pb was significantly associated with a 0.32 mm Hg(95% CI: 0.01, 0.63) increase of systolicblood pressure and a 0.25 mm Hg (95% CI:0.07, 0.43) increase of diastolic blood pressure in all women without respect tomenopausal status. In analyses stratified by menopausalstatus, only postmenopausalwomen showed a significant blood Pb effect. For each 1 μg/dL increase of blood Pbwas associated with significantly increased diastolic blood pressure of 0.14 (95% CI:−0.11, 0.39sic.) only in postmenopausal women.Referenced to the 1st blood Pb quartile,no other quartile showed significantlyincreased odds for hypertension in all subjectsor in subjects stratified by menopausalstatus. With further analyses stratified bysystolic and diastolic hypertension withoutwomen taking antihypertensive medications, in the combined group of pre andpostmenopausal women the oddsof diastolic hypertension were significant when the4th Pb quartile was compared to the 1st quartile (OR = 3.4 [95% CI: 1.3, 8.7]). In amodel of only postmenopausalwomen untreated for hypertension, odds of diastolichypertension were significantly increasedin the higher three quartiles of blood Pb(OR = 4.6 [95% CI: 1.1, 19.2], OR = 5.9 [95% CI: 1.5, 23.1], OR = 8.1 [95% CI:2.6, 24.7], respectively) and odds of systolichypertension were significant only for thetwo middle Pb quartiles (OR = 3.0 [95% CI: 1.3, 6.9], OR = 2.7 [95% CI: 1.2, 6.2],respectively).Linear blood Pb is suspect in linear regression models of bloodpressure as it isusually associated with biased and inefficient estimation of Pb coefficients due toprobable heteroscedasticityand non-normal distribution ofresiduals. No modeldiagnostics were reported. Nostatistical testing for differences in Pb coefficientsaccording to strata. Nine stratified models overall. Not all stated significance levelsand standard errors in the blood pressure model table corresponded for certainvariables.

# AX6-138Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Proctor et al.(1996)U.S.-Boston-Normative AgingStudy (VA)1992-1993798 men from 17 to 44 yrs.Multiple linear regression modelsof natural log blood Pb onsystolic and diastolic bloodpressure. All covariates forcedinto model.Arithmetic mean (SD,range) blood Pb:6.5 μg/dL (4.0, 0.5-35)Natural log blood Pb, age, age-squared, BMI, adjusted dietary calcium, exercise,indicator variables for current and formersmoker, daily alcohol consumption, sittingheart rate, and hematocrit were entered into multiple regression models without regardfor significance.Increased diastolic, but not systolic, blood pressure was significantly associated withincreased blood Pb. Each natural log increase in blood Pb was associated with a1.2 mm Hg (95% CI: 0.1, 2.2) increase in diastolic blood pressure.Interactions between dietary calcium and blood Pb onblood pressure were notsignificant. Further analyses stratifiedon use of antihypertensive medication andthose older than or equal to 74 yrs stillrevealed significant blood Pb-diastolic bloodpressure relationships.Blood Pb in over half the study group (n = 410) was determined by analyzingpreviously frozen erythrocytes collected several yrs prior to the blood pressuremeasurements used in the study and corrected by using hematocrit values alsomeasured when blood was originally collected. Combining both groups means thatnearly half the group was tested for the effects of blood Pb on blood pressuremeasured at the same time, the other half measured several yrs apart. There was nocorrection in models for this potential effect. The effect of taking antihypertensivemedication could have been assessed in a single model by using an indicator variable.No statistical testing for the effects ofstratification on the blood Pb-blood pressurerelationship. No model diagnostics.

# AX6-139Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Rothenberg et al.(1999)U.S.-Los Angeles1995-19981188 immigrants and 439 nonimmigrants,from 15 to 43 yrs, all women in 3rdtrimester of pregnancy. Multipleregression models of natural log blood Pbon systolic and diastolic blood pressurewith all covariates forced into models.Covariates selectedfrom larger set basedon significant univariate or bivariate tests.Geometric mean (SD)blood Pb:Immigrants: 2.3 μg/dL(1.4)Non-immigrants:1.9 μg/dL (1.3)Natural log blood Pb, age, BMI, coffee drinking, iron supplementation, and job stresswere entered as a block without regard to significance in linear multiple regressionmodels of systolic and diastolic blood pressure stratified by immigration status.Increased blood Pb was significantly associated with increased blood pressure only inimmigrants. Each natural log unit increase in blood Pb was associated with a1.7 mm Hg (95% CI: 0.7, 2.8) increase insystolic blood pressure and a 1.5 mm Hg(95% CI: 0.5, 1.9) increase in diastolic blood pressure in immigrants.Used and reported model diagnostic tests, asevidenced by the use of standard errorcalculations robust to residual heteroscedasticity. Stated reasons for stratification onimmigrant status were significant differences between the two groups in blood Pb,blood pressure, age, BMI, and education. Did not statistically test difference in Pbcoefficients between the immigration strata. Did not correct for potential non-linearityin age effects on blood pressure.Rothenberg et al.(2002a)U.S.-Los Angeles1995-2001668 women, 15 to 44 yrs, studied in 3rdtrimester pregnancy and again a mean of10 wks postpartum. Exclusion criteriawere diabetes, renal or cardiovasculardisease, extreme postnatal obesity(BMI >40), and subjects using stimulantdrugs. Multiple linear regression modelsof natural log blood Pb, tibia andcalcaneus Pb on systolic and diastolicblood pressure with all covariates and allPb variables forced into model. Separatemodels for 3rd trimester and postpartum,excluding all women with hypertension(see below) during each specific period.Logistic regression for hypertension(systolic∃140 mm Hg or diastolic∃90),specific to 3rd trimester and postpartumperiods with the same covariates and Pbvariables.Geometric mean bloodPb (SD):3rd trimester:1.9 μg/dL (1.7)Postpartum: 2.3 μg/dL(2.0)Tibia mean Pb (SD):8.0 μg/g (11.4)Calcaneus mean Pb(SD):10.7 μg/g (11.9)Multiple linear regression models for normotensives adjusted for postnatalhypertension (3rd trimester model only), BMI,age, parity, smoking, alcohol,immigrant status, and educational level plus all three Pb indices. Only calcaneus Pbwas associated with blood pressure in 3rd trimester models. Every 10 μg/g increase incalcaneus Pb was associated with 0.70 mm Hg (95% CI: 0.04, 1.36) increase insystolic blood pressure and a 0.54 mm Hg (95% CI: 0.01, 1.08) increase in diastolicblood pressure. In postpartum models, natural log blood Pb was the only variablestatistically associated with blood pressure. Every natural log unit increase in bloodPb was associated with!1.52 mm Hg (95% CI:!2.83,!0.20)decrease in systolicblood pressure and a−1.67 mm Hg (95% CI:!2.85,!0.50) decrease in diastolic bloodpressure.In logistic models, only calcaneus Pb was significantly associated with increased oddsfor hypertension. Each 10 μg/g increase in calcaneus Pb was associated with an OR =1.86 (95% CI: 1.04, 3.32) of 3rd trimesterhypertension. None of the Pb variableswas associated with postpartum hypertension.Models did not use age-squared covariate.Models did not use repeated measuresstatistics. No statistical comparisons between 3rd trimester andpostpartum models.Model diagnostic tests reported.

# AX6-140Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Schwartz et al.(2000c)U.S.-Eastern1996-1997543 mostly former organoleadworkers, predominantly white(92.8%), at a tetraethyl/tetramethylplant, mean (SD) [range] age 7.6 (7.6)[41.7-73.7] yrs had blood Pb, DMSA-chelatable Pb (4-hr. urinary Pbexcretion after a single 10 mg/kg doseof DMSA) measured for modelingsystolic and diastolic blood pressureand hypertension (systolic >160mm Hg or diastolic∃96 mm Hg ortaking antihypertensive medications.Tibia Pb ~2 yrs later was also used asa Pb index. For blood pressure, linearmultiple regression with backwardelimination of non-significantcovariates or covariates that “hadimportant influence on the coefficientsfor the Pb-dose terms.” Each Pbvariable was tested in a separatemodel. Potential covariates for thesemodels were age, BMI, currenttobacco use, and current use ofantihypertensive medications. Othermodels were constructed taking outthose subjects using antihypertensivemedications. Both linear and linear +quadratic blood and tibia Pb termswere tested. Logistic regressionanalyses were used to test the effect ofthe Pb variables on hypertension,controlling for age, diabetes, lifetimealcohol consumption, and BMI.Logistic models also tested each Pbmeasure in interaction with age.Blood Pb arithmeticmean (SD, range):4.6 μg/dL (2.6, 1to 20)DMSA-chelatable Pbmean (SD, range):19.0 μg (16.6, 1.2to 136)Tibia Pb mean (SD,range): 14.4 μg/g(9.3,!1.6 to 52)Adjusting for age, BMI, current smoking, andcurrent use of antihypertensive medications,each 1 μg/dL increase in blood Pb-squared was significantly associated with 0.189 mm Hg(95% CI: 0.087, 0.330) increase in systolic blood pressure with three outliers removed.With the same covariates, each 1 μg/dLincrease in linear blood Pb was significantlyassociated with 0.310 mm Hg (95% CI: 0.028, 0.592) in diastolic blood pressure takenover a 2-yr period (n = 525). No other Pb variables were significant.For the hypertension models, only the interaction of linear blood Pb by age was significant,with subjects showing significant decrease in odds ratio of hypertension with every jointincrease of 1 μg/dL blood Pb and 1 yr increase in age (linear blood Pb X age OR = 0.98;[95% CI: 0.97, 0.99]). The interaction suggested a concentration-response relationshipbetween linear blood Pb and hypertension only up to ~58 yrs of age.Authors note that blood pressure findings “werenot affected by exclusion or inclusion ofsubjects using antihypertensive medications,”but do not present either the data or thestatistical tests to evaluate that conclusion.No other model diagnostics were reported.Although blood Pb was also modeled as a quadratic Pb term for systolic blood pressure, noanalysis was shown for non-linear blood Pbterms for diastolic blood pressure.Trabecular bone Pb was not tested, though otherstudies indicate that it is a better Pb indexthan cortical Pb for cross-sectional blood pressure and hypertension study.Although the backward procedures described could have resulted in less than the full set ofconsidered covariates entering the models, all model presentations were limited to showingthe Pb coefficients and all models indicated in a footnote that the Pb coefficients wereadjusted for each possible covariate for that model. While this is possible with the shortlist of covariates, given the 14 models presented one might expect to see at least one modelwhere one of the covariates did not remain.

# AX6-141Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Schwartz (1995)15 prior U.S. andEuropean studiespublished between1985 and 1993Total subjects not specified, men andwomen ages 18 to 74 yrs. Randomeffects meta-analysis with inversevariance weighting of Pb-bloodpressure coefficients from each study.Sensitivity analysis performed bydropping study with largest or smallesteffect.Blood Pb levels notstated.Each doubling of natural log blood Pb level was associated with an increase of 1.25mm Hg (95% CI: 0.87, 1.63) systolic bloodpressure. Sensitivity analysis showednegligible change in meta-analysis coefficient. Concluded that adding newer studieswould not change calculated coefficient.Noted Pb-blood pressure slope was larger atlower Pb levels than at higher Pb levels.The study only analyzed systolic, not diastolic, blood pressure. Superseded byNawrot et al. (2002).Schwartz (1991)NHANES IIU.S.1976-1980Under 10,000 subjects (exact numbernot reported), males and females, aged25 to 74 yrs for left ventricularhypertrophy results with logisticregression. Linear blood Pb used forLVH. For blood pressure results,multiple linear regressions stratified bysex, with one block of variablesforced, another block of variablesentered with stepwise regression, aged6 mos to 74 yrs, exact number notgiven. Natural log blood Pb used forlinear regression. Both logistic andlinear regressions adjusted for surveydesign.No blood Pbdescriptive datagiven.Used logistic regression to study Pb effect on left ventricular hypertrophy (LVH)determined by a combination of electrocardiogram parameters and body habitus,controlling for age, race, and sex. Every 10 μg/dL blood Pb increase was associatedwith increased odds of LVH of 1.33 (95% CI: 1.20, 1.47). Interaction terms for raceby blood Pb and sex by bloodPb were not significant.Blood pressure models stratified by sex always included BMI, age and age-squared,race, and natural log blood Pb. Male blood pressure model also included familyhistory of hypertension, cholesterol, height,cigarette use, serum zinc, and tricep skinfold. Female model also included serum zinc, family history of hypertension, tricepskin fold, and cholesterol. Every 1 natural log unit of blood Pb increase wasassociated with an increase in diastolic blood pressure of 2.93 mm Hg (95% CI: 0.93,4.98) in males and 1.64 mm Hg (95% CI:0.27, 3.01). Used interaction terms forrace-blood Pb and sex-blood Pb in a non-stratified model and found no significanteffect of race or sex on the blood Pb-blood pressure coefficient.Incomplete reporting of subject size for models and for descriptive statistics for allvariables in models. Tested both linear and log transformed Pb in preliminary testing.Found log Pb had lower probability values than linear Pb for blood pressure, andlinear Pb had lower probability values than log Pb for LVH. No testing of significantdifference between the two blood Pb specifications. No model diagnostics reported.Only reported diastolic blood pressure results.

# AX6-142Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Sokas et al. (1997)U.S.-Maryland1989-1990264 active or retired constructionworkers, over 99% men, who were notinvolved in Pb work at time of testing,mean age (range) 43 yrs (18-79).Multiple regression modeling ofsystolic and diastolic blood pressureadjusted for covariates of BMI, age,hematocrit, erythrocyteprotoporphyrin, race, linear blood Pband a race-linear blood Pb interaction.Method of covariate entry not madeexplicit, though it appeared to beforced.Mean blood Pb(range): 8.0 μg/dL(1-30)Linear blood Pb was not significantly related to either systolic or diastolic bloodpressure, though the race by linear bloodPb interaction was marginally significant(p = 0.09). Each 1 μg/dL increase in bloodPb increased black systolic blood pressure0.86 mm Hg (no SE or 95% CI reported) more than white systolic blood pressure.Linear blood Pb term may not be appropriate. Small sample compromisesinterpretation of non-significant results.By using erythrocyte protoporphyrin andblood Pb in the same model, these two measures of Pb exposure may have beenconfounded. Incomplete reporting of procedures and results.No model diagnostictests reported.Sorel et al. (1991)U.S.-NHANES II1976-19802056 females, 2044 males, 473 blacksand 3627 whites, from 18-74 yrs, wereused in survey design and weightadjusted multiple linear regressionsstratified by sex, with separate modelsfor systolic and diastolic bloodpressure. Covariates included age,BMI, race, and poverty income ratioand linear blood Pb. Method ofcovariate entry not specified but mayhave been forced. Different covariategroups were used for different models.Primary test for the effect of race onthe Pb-blood pressure relationship wasto note the change in the racecoefficient in modelswith and withoutthe linear blood Pb variable.Age-adjustedarithmetic meanblood Pb:Black female:13.2 μg/dL (novariance informationfor any blood Pb)White female:12.1 μg/dLBlack male:20.1 μg/dLWhite male:16.8 μg/dLLinear blood Pb was significantly related only to diastolic blood pressure in males,adjusting for age and BMI. For every 1 μg/dL blood Pb increase diastolic bloodpressure increased 0.13 mm Hg (95% CI: 0.04, 0.21). Adding race to the model withand without linear blood Pb terms did not appear to change the race coefficient.Adding poverty index to the models withand without blood Pb produced the samesmall change in poverty index coefficient.Linear blood Pb may not be appropriate. Only confidence intervals were used toassess the significance of changes in race and poverty index coefficients acrossmodels with and withoutPb, instead of using interaction terms of these two variableswith Pb. Incomplete reporting of procedures and results. Nomodel diagnostic testsreported.

# AX6-143Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Sharp et al. (1990)U.S.-SanFrancisco, CA1986After exclusion of subjects undertreatment for hypertension, 249 malebus drivers, 132 of whom were black,age from 31 to 65 yrs, were used inrace stratified multiple regressionmodels of systolic and diastolic bloodpressure with covariate forced entry ofage, age-squared, BMI, caffeine use,tobacco use, and natural log blood Pb.Alcohol use was added in othermodels. Other models stratified bycaffeine use.Geometric mean (range)blood Pb:Black males: 6.5 μg/dL (3-21)Non-black males:6.2 μg/dL (2-15)Significant log blood Pb effects were noted inblacks. In models excluding alcoholuse, for every one natural log unit increase of blood Pb, systolic blood pressure rose7.53 mm Hg (95% CI: 0.86, 14.2) and diastolic blood pressure rose 4.72 mm Hg(95% CI: 0.15, 9.29). Stratified by infrequent/frequent caffeine users, only blackinfrequent caffeine users showed a significant response to blood Pb. For every onenatural log unit increase of blood Pb, systolic blood pressure rose 16.69 mm Hg (95%CI: 3.83, 29.5) and diastolic blood pressurerose 10.43 mm Hg (95% CI: 1.26, 19.6).Non-black blood pressure was decreasedwith increasing natural log Pb but wasmarginally significant. In all non-black subjects, for every unit increase in natural logblood Pb, systolic blood pressure decreased−5.71 mm Hg (95% CI:−12.0, 0.6).Addition of alcohol to the models decreased all coefficients a small amount.Progressive addition of age, BMI, caffeine, and tobacco, in that order, progressivelyincreased the coefficient of natural log bloodPb in models of systolic and diastolicblood pressure in blacks. Removal of two black outliers did not materially change theresults for blacks.No statistical tests for comparing stratifiedmodels, models withand without caffeineuse, effect of progressive addition of covariates, or addition of alcohol. Influencediagnostics reported for detecting the two outlying subjects. No other diagnostic testsreported. Small differences in text and table reports of the same coefficients. Smallsample size limits interpretation of non-significant results.

# AX6-144Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Tepper et al.(2001)U.S.-Cincinnati,OHAfter 1991 tobefore 200143 females and 57 males, current orformer workers at a Pb-acid batteryfactory, between 36 and 73 yrs of age,with at least 10 yrs working in batteryproduction, participated. Multivariateregression models and logisticregression models were constructed toassess Pb exposure effect on outcome(hypertension: >140/90 mm Hg and>160/95 mm Hg or takingantihypertensive meds; diastolic andsystolic blood pressure, and leftventricular mass/body surface area(g/m2). Echocardiograms were used todetermine left ventricular mass.Variables used to adjust all modelswere age, BMI, sex, and family historyof hypertension.Plant blood Pb records wereused to calculate cumulativeblood Pb index (CBLI) used asa tertile measure, a linearcontinuous measure, and a logtransformed measure.CBLI μg/dL-yr1st tertile: 138-5042nd tertile: 505-7463rd tertile: 747-1447Time-avgd blood Pb TABL)was treated the same way:TABL μg/dL1st tertile: 12-252nd tertile: 26-333rd tertile: 34-50No odds ratios were given for hypertensionand any Pb variable for hypertensiondefined as >140/90 mm Hg butORs were claimed not significant. Odds ratios were2.71 and 1.44 for the 3rd tertile CBLI and TABLPb measures compared to 1st tertile,apparently significant, but no probabilities, SEs or CIs given.With the 81 subjects not taking anti-hypertensive meds, neither CBLI tertile norTABL tertile were significantly associatedwith either diastolic or systolic bloodpressure (coefficients, SEs or 95% CIsnot given). Using log transformed CBLIprobability of a positive association with diastolic blood pressure was 0.06. Using logtransformed TABL, probabilityof a positive association with diastolic blood pressurewas 0.10. No coefficients, SEs, or CIs given.Left ventricular mass adjusted for body surface area was not significantly related toany Pb measure. No coefficients, SEs or CIs given.Despite the certainty of the authors that “we found no convincing evidence of anassociation...”, the very low power of thisstudy gives certainty to none of thefindings. Very poor reporting of results further reduces the possibility of evaluation.No model diagnostic testing was reported.

# AX6-145Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Vupputuri et al.(2003)U.S.-NHANES III1988-19945188 white women, 2300 blackwomen, 5360 white men, and 2104black men, aged 18 yrs and older.Survey adjusted multiple linear andlogistic regression were used to assesslinear blood Pb effect on systolic anddiastolic blood pressure andhypertension in race and sex stratifiedmodels.Arithmetic mean (SD)blood Pb:White women 3.0 μg/dL (7.2)Black women 3.4 μg/dL (4.8)White men 4.4 μg/dL (7.3)Black men 5.4 μg/dL (9.3)Multiple linear regression models were all adjusted for age, education, BMI, alcoholconsumption, leisure time physical activity, dietary sodium and potassium, and totalcalories. Only black women and men showed significant linear Pb effects. Every1 μg/dL increase in blood Pb was associated with an increase of 0.47 mm Hg (95%CI: 0.14, 0.80) in systolic and 0.32 mmHg (95% CI: 0.11, 0.54) diastolic bloodpressure in black women, and 0.25 mm Hg(95% CI: 0.06, 0.44) systolic and 0.19mm Hg (95% CI: 0.02, 0.36) diastolic blood pressure in black men.Odds of hypertension (systolic∃140 mm Hg, diastolic∃90 mm Hg, or takingantihypertensive medication) significantlyincreased for every SD (3.3 μg/dL) ofblood Pb level in black women (OR = 1.39 [95% CI: 1.21, 1.61]), in white women(OR = 1.32 [95% CI: 1.14, 1.52]), in black men (OR = 1.26 [95% CI: 0.99, 1.19]),but not in white men.Linear blood Pb terms are usually not appropriate in multiple linear regression modelsof blood pressure. Furthermore, they reportedtheir results in terms of change in 1 SDunit of Pb. Linear SD of Pb is incorrect for log-normal distributions of blood Pb. Nomodel diagnostic tests reported. Discrepancy between Methods report of race-Pb andsex-Pb interactions in simple, not multiple, analyses, but Results reports significantinteractions for race-Pb and sex-Pb in multiple regression models for both linearregression and logistic regression models, without showing the results of theinteraction analyses. The probability of the stated interactions (p < 0.001) appearsextremely low, given the degree of 95%CI overlap in Pb coefficients among thestratified models. No model diagnostics reported.

# AX6-146Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEuropeBost et al. (1999)Europe-England-Health Survey forEngland19952763 women and 2563 men from a multi-stage stratified probability surveyrepresentative of the English populationliving in private residences, mean (SE) agefor men 47.5 yrs (0.34) and for women 47.7yrs (0.33) (all subjects 16 yrs and older)were used in an analysis of blood Pbassociation with systolic and diastolic bloodpressure. Stepwise multiple regressionanalysis were used testing natural log bloodPb against common log systolic bloodpressure and non-transformed diastolicblood pressure, with the following potentialcovariates: age,BMI, smoking status,region of residence, social class, andalcohol consumption.Models werestratified by sex, with and withoutadjustment for alcohol, including orexcluding those taking antihypertensivemedications.Geometric mean blood Pb:Men: 3.7 μg/dL (no statedmeasure of variance)Women: 2.6 μg/dL(no stated measure ofvarianceModel tables presented only standardized variable coefficients. The mostconsistent results were reported on common log Pb association with men’sdiastolic blood pressure. Every doubling of blood Pb was significantlyassociated with an increase of 0.78mm Hg (95% CI: 0.01, 1.55) diastolicblood pressure, adjusted for age, logBMI, and alcohol, but excluding menon antihypertensive medication. Every doubling of blood Pb wassignificantly associated with an increase of 0.88 mm Hg (95% CI: 0.13,1.63) in the same model with men onantihypertensive medication. Everydoubling of blood Pb was significantly associated with an increase of 0.96mm Hg (95% CI: 0.23, 1.70) in the same model excluding men onantihypertensive medication and not adjusting for alcohol. Every doublingof blood Pb was significantly associated with an increase of 1.07 mm Hg(95% CI: 0.37, 1.78) including men taking antihypertensive medication andnot accounting for alcohol. None of the multiple regression models hadsignificant Pb terms for women.This report was not sufficiently detailed. Stepwise regression modeling isprone to the usual pitfalls. Survey design adjusted analysis not used. Pbwas not entered in models in which criterion probability was exceeded(p > 0.05). No rationale given for stratifying. No testing of differencesamong Pb coefficients for the different models was made, which would havebeen especially valuable to compare models adjusted and not adjusted foralcohol use. No explanation for using log systolic blood pressure asdependent variable. Nomodel diagnostics reported.

# AX6-147Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Fewtrell et al.(2004)Global1988-2002Using available global figures oncategorized blood Pb ranges by age group,authors calculated relative risk ratiosrelating increased blood pressure toischemic heart disease, cerebrovasculardisease, hypertensivedisease, and othercardiac diseases. Theyused a calculation of“impact fraction,” based on the proportionof the population within the particular Pbexposure category and the relative risk atthat exposure category compared to the riskat the reference level. They used the meta-analysis of Schwartz (1995) to derive anaccumulating 1.25 mm Hg increase inblood pressure in men for 5-10, 10-15, and15-20 μg/dL, and an increase of3.75 mm Hg for blood Pb levels above20 μg/dL. Comparable blood pressureincreases in women for each Pb categorywas 0.8 mm Hg for each of the first threecategories and 2.4 mm Hg for blood Pb>20 μg/dL.See left for blood Pbcategories used.The largest risk ratios were for hypertensive disease populations at ages 15-44,calculated at 1.12, 1.41, 1.78, and 2.00 for each of the four Pb categories formen, and 1.08, 1.25, 1.45, and 1.56 forwomen. Risk ratios for all diseasecategories increased withincreasing Pb category anddecreased for populationsolder than 44 yrs.The authors assumed a linear relationship between blood pressure and bloodPb, whereas available evidence suggests it may be non-linear. If blood Pbblood pressure concentration-responsefunction is log-linear, as implicitlyaccepted by over half the reviewed studies, the calculated global risk ratios forall cardiovascular disease will be overestimated at higher blood Pb levels andunderestimated at lower blood Pb levels.

# AX6-148Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Maheswaran, et al.(1993)Europe-England-Birmingham1981809 out of 870 workers, mean (SD)age 43.3 (10.4) yrs, at an Pb acidbattery plant were used in the study.Women and workers takingantihypertensive medications wereexcluded. Used multiple linearregression analyses of systolic anddiastolic blood pressure, forcing age,BMI, alcohol use,linear blood Pb, zincprotoporphyrin, yrs of work exposure,cigarette smoking as covariates.Geometric mean(SD) blood Pb:31.6 μg/dL (5.5)Linear blood Pb was not significant for either systolic or diastolic blood pressure.Authors used two indices of Pb exposure in the same models. Over much of the studiedblood Pb range, zinc protoporphyrin was likely collinear with blood Pb. Linear blood Pbmay not be the appropriate metric to use in blood pressure models. Did not use age-squaredto adjust for non-linear relationship of bloodpressure with age. Did not report modeldiagnostics.Menditto et al.(1994)Europe-RomeNew Risk FactorsSurvey1989-19901319 males, mean (range) age 63 (55-75) yrs, not treated for hypertension,were used in forward stepwisemultiple linear regression models ofsystolic and diastolic blood pressurewith available covariates of age, BMI,heart rate, serum high densitylipoprotein, non-high densitylipoprotein, triglycerides, glucose,cigarette use, alcoholuse, sum of fiveskinfold thicknesses (triceps, biceps,subscapular, suprascapular, andsuprailiac), and natural logtransformed blood Pb.Median (2.5th-97.5thpercentiles, range)blood Pb: 11.3 μg/dL(6.2-24.7, 4-44.2)Only BMI, heart rate, and serum glucosewere not simultaneously and significantlycorrelated with both natural log blood Pb and blood pressure. In a systolic blood pressuremodel adjusted for BMI, age,heart rate, high and non-high density lipoprotein, triglycerides,glucose, and cigarettes, each unit increasein natural log blood Pb was significantlyassociated with a 5.6 mm Hg (95% CI: neither SEnor CI stated) increase in blood pressure.In a diastolic blood pressure model adjusted for BMI, heart rate, age, cigarettes, triglycerides,and high density lipoprotein, each unit increase in natural log blood Pb was significantlyassociated with a 1.7 mm Hg (95% CI: neither SEnor CI stated) increase in blood pressure.In stratified models for alcohol drinkers (n = 1068) and non-drinkers (n = 251) only alcoholdrinkers showed significant natural log blood Pbassociated blood pressure increase, with Pbcoefficients similar to those of the entire group.Authors observed change in natural log blood Pb coefficient produced by successive additionof covariates to models. In no case did the coefficients change by more than 30% afteraddition of a covariate. Authors noted that wine was the predominant drink in alcohol usersand that the correlation between alcohol consumption and natural log blood Pb level was thehighest among all correlations reported (p < 0.001; correlation coefficient not stated).No statistical tests were made to determine ifthe change in Pb coefficients with addition ofcovariates was significant, nor were statistical tests made to determine if the Pb coefficientsin the alcohol use stratified models were significantly different. Small size of the nonalcohol drinking group in stratified analysis precludes interpretation of non-significanteffects. Incomplete reporting of results. Paper published in a supplement issue reportingmeeting papers may indicate that it received less that thenormal peer-review scrutiny forpublished research articles. No model diagnostic tests were reported.

# AX6-149Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Møller andKristensen (1992)Europe-Denmark-CopenhagenCounty-GlostrupPopulation Studies1976-1990A cohort born in 1936 was followed atage 40 (women n = 546, men n = 504),age 45 (women n = 430, men n = 463) andagain at age 51 (men only n = 439).Reported no difference in results ifsubjects taking antihypertensivemedications were excluded. Reportedresults included these subjects. Linearmultiple regression models of systolic anddiastolic blood pressure of follow up,stratified by sex and by yr, used asequence of forced entry of covariates:natural log blood Pb was tested alone(unadjusted), then adjusted for tobacco,cholesterol, physicalactivity, and sex(Model 1), then adjusted for the abovecovariates plus systolic blood pressure(Model 2), and then adjusted for the abovecovariates plus alcohol (Model 3).Another group of linear multipleregression models ofchange of systolicand diastolic blood pressure from age 40to 51 yrs in men only, following the samecovariate entry scheme as above, but usedchange in covariates instead of theoriginal covariates. All subjects werefollowed until 54 yrs of age (from 1976 to1990) to assess Pb association with totalmortality and with coronary heart disease(CHD; ICD-8 410-414) andcardiovascular disease (CVD; ICD-8 430-435) combined morbidity and mortalityusing Cox proportional hazards models(n = 1050). Cox modelswere adjusted asabove.Arithmetic mean (SD,range) blood Pb by ageand sex:Women 40 yrs:9.6 μg/dL (3.8, 4-39)Women 45 yrs:6.8 μg/dL (3.5, 2-41)Men 40 yrs: 13.6 μg/dL(5.7, 5-60)Men 45 yrs: 9.6 μg/dL(4.3, 3-39)Men 51 yrs: 8.3 μg/dL(4.1, 2-62)In women, each one unit increase in natural log blood Pb was associated with asignificant increase in systolic blood pressure of 4.93 mm Hg (p = 0.002; neither SE norCI stated) at age 40 and an increase of 2.64mm Hg (p = 0.06; neither SE nor CI stated)at age 45, in models adjusted for tobacco,BMI, and physical activity (Model 1). Whenalcohol (Model 2) or alcohol plus hemoglobin (Model 3) were added to the models Pbblood pressure relationships were not significant at either age. With each one unitchange in natural log blood Pb, diastolicpressure increased 4.26 mm Hg (p = 0.002;neither SE nor CI stated) at 40 yrs and 3.26 mm Hg (p = 0.002; neither SE nor CIstated) at 45 yrs in Model 1. In Model 2,the increase in diastolic blood pressure was3.21 mm Hg (p = 0.02; neither SE nor CI stated) at 40 yrs and 2.86 mm Hg (p = 0.01;neither SE nor CI stated) at 45 yrs. In Model 3, the increase in diastolic blood pressurewas 2.65 mm Hg (p = 0.07; neither SE norCI stated) at 40 yrs and 2.78 mm Hg(p = 0.01; neither SE nor CI stated) at 45 yrs.In men, the only significantassociation between natural log blood Pb and bloodpressure was at 45 yrs. For every increase of one unit of natural log blood Pb theincrease in systolic blood pressure was2.73 mm Hg (p = 0.05; neither SE nor CIstated).The change in blood Pb between 40 and 51 yrs was not significantly associated withchange in systolic or diastolic blood over the same period in any of the models.None of the relative hazard ratios for CHD andDVD combined morbidity and mortalitybetween 40 and 54 yrs were significantly related to blood Pb concentration. Totalmortality, however, was significantly increased with increased blood Pb. In Model 1,every increase of one natural log unit of blood Pb was associated with an increasedrelative hazard of mortality of 1.96 (p = 0.009; neither SE nor CI stated). For Model 2,every increase of one natural log unit of blood Pb was associated with an increasedrelative hazard of mortality of 1.82 (p = 0.03;neither SE nor CI stated). There were 40cases of CHD recorded, of which 13 were fatal. There were 54 cases of CVD recorded,of which 19 were fatal. Of the total of46 subjects who died during the period, 32(70%) died of cardiovascular problems. It was not clear if blood Pb at a particular ageor a mean blood Pb across ages was usedin the Cox proportional hazards models.

# AX6-150Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Møller andKristensen (1992)(cont’d)Though this study was one of the few touse a longitudinal design, it did nottake advantage of that design feature in blood pressure modeling. Cross-sectional multiple regression modeling at each age loses valuable informationavailable in repeated measures modeling. Power to detect significant effects ismuch higher in repeated measurement modeling than in cross-sectionalmodeling. Analyzing only change inblood pressure loses informationregarding starting and ending blood pressure. Including change in blood Pb isproblematical due to the unknown history ofPb exposure prior to the start ofthe study, the resultant bone Pb load asa result of past exposure, the unknownPb contribution of bone to blood, and the unknown relative contributions ofpast exposure and present exposure toalteration in blood pressure. Modelingother covariates as change is also questionable. BMI, to pick a covariate withknown and strong effects on blood pressure, may be high and relativelyconstant over the study period or low and relatively constant over the study. Inboth cases, the change in BMI will besmall, but the high BMI will beassociated with higher blood pressure thanwill the low BMI. Thus, both casesmodeled as change in BMI should have the same effect on blood pressurewhen the high BMI subject has expectedhigher blood pressure than the lowBMI subject. Using difference scoresfor the dependent and the exposurevariables also risks confounding secular trends in either or both of thesevariables, for whatever reasons, with independent difference variable effect ondependent difference variable effect.The Cox proportional hazards model, however, is longitudinal in nature.Failure to detect significant associations between Pb and cardiovascularmorbidity/mortality could have been due tothe small sample size used for thistype of analysis. The blood pressure part of the study did not take mortalityinto account during the study, which could have produced a progressivelyincreasing “healthy subject” effect. Since subjects taking antihypertensivemedications were included in analyses, anindicator variableshould have beenused to account for them, whether or nottheir exclusion in preliminary testingproduced no apparent change in results. This paper contained a gooddiscussion of confounding variables. Incomplete reporting of results andprocedures. No model diagnostic tests were reported.

# AX6-151Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Staessen et al.(1996a)Europe-Belgium-PheeCad study.1985-1995359 men and 369 womenparticipated at baseline (between1985 and 1989) and again about 5yrs later (median 5.2 yrs) atfollow up (between 1991 and1995), mean age (range) atbaseline 46 yrs (20-82), abouthalf of whom were recruited fromtowns surrounding a non-ferroussmelter (targeted to produce highcadmium exposure) and half fromtowns without heavy metalproduction. Over half the menhad occupational exposure(59.0% from the near smeltertowns, 17.4% from the othertowns).Four different outcomes wereexplored: time-integratedconventional blood pressure (avgof 10 baseline and 5 follow upblood pressure measurements),24-h ambulatory blood pressureonly during the follow up period(avg of readings every 20 minutesfrom 8 AM to 10 PM and every45 minutes from 10 PM to 8 AM,weighted by interval betweenmeasurements), difference inconventional blood pressure overthe five yr follow up period, andincidence of developinghypertension during follow up.Geometric mean (5th95th percentile) by sexand time period:Baseline women:6.6 μg/dL (3.3-14.5)Follow up women:4.8 μg/dL (1.7-11.8)Baseline men:11.4 μg/dL(5.6-28.8)Follow up men:7.7 μg/dL(3.7-20.1)The study was one of the few prospective longitudinal studies reported and was innovative in itsuse of 24-h ambulatory blood pressureas one of its outcome variables.Time-integrated conventional blood pressure models:In 187 peri- and post-menopausal women,after adjusting for age, BMI, gammaglutamyltransferase activity, and hematocrit, each increase of one unit of natural log blood Pbwas associated with an increase in diastolic blood pressure of 7.49 mm Hg (95% CI: 1.48,13.50). No other time-integrated conventionalblood pressure measurements were significantlyassociated with time-integrated natural log blood Pb in either men or women, nor in stratifiedgroups within sex.Ambulatory 24-h blood pressure models:In all 345 women, after adjusting for age, hematocrit, gamma-glutamyltransferase activity, andoral contraceptive use, each one unit increase in natural log blood Pb was associated with anincrease of diastolic blood pressure of 3.49 mmHg (95% CI: 0.02, 6.96). When the group waslimited to the 174 premenopausal women eachunit increase in natural log blood Pb wasassociated with an increase of diastolic bloodpressure of 5.48 mm Hg (95% CI: 0.56, 10.40).Difference in blood pressure between baseline and follow up:After adjustment for change in BMI, beginning use of antihypertensive medication andcontraceptive medication during the follow upperiod, and starting smoking there was nosignificant relationship between difference in either systolicor diastolic bloodpressure and bloodPb in women. After adjustment for change in BMI, change in exposure at work, change insmoking, beginning use of antihypertensive medication in men there was no significantrelationship between difference ineither systolic ordiastolic blood pressure and blood Pb inmen.Incidence of hypertension:At baseline 107 (14.7%) and 120 (16.5%) subjects had borderline and definite hypertension,respectively. At follow up 98 (13.5%) and 186 (25.5%) had borderline and definitehypertension, respectively. 51 of 501 initially normotensive subjects became borderlinehypertensive and 47 of the 501 became border linehypertensive during the follow up period.After adjusting for sex, age, and BMI, natural log baseline blood Pb was not related to significantrisk ratios of becoming hypertensive (not stated, but presumably combined definite andborderline hypertension) or becoming a definite hypertensive.

# AX6-152Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Staessen et al.(1996a) (cont’d)Multiple regression models were used to test theassociation between natural log transformedblood Pb (mean of baseline and follow up Pb)and blood pressure (systolic and diastolic),stratified by sex, then further stratified by use ofantihypertensive medications in men andmenopausal status in women. Age and age-squared (calculated in quintiles) were forced intothe models, then remaining covariates werestepwise added to the model. Though notexplicitly stated, natural log blood Pb (mean ofbaseline and follow up) was likely forced in last.Other candidate covariates were BMI,hemoglobin or hematocrit, serum gamma-glutamyltransferase activity (an index of alcoholuse) and serum calcium, 24 h urinary sodium andpotassium excretion, energy expenditure,exposure to heavy metals (at the workplace),social class, smokingand drinking habits,menstrual status in women, and use ofantihypertensive medications, oral contraceptives,and hormone replacement therapy. In ambulatoryblood pressure models,differences betweenbaseline and follow up blood pressure modelswere constructed in the same way. For thedifference models “concurrent variations in bloodPb concentrations” were used, presumablydifference in baseline and blood Pb.The study does not use the full power of repeated measurements in theanalyses. For problems encountered when collapsing repeatedmeasurements to difference measures, see Møller(1992) above. Stepwiseregressions are prone to capitalizing on chance results due to multipletesting of the same data and almostalways produce a different mix ofcovariates when they are stratified. Thus, it was puzzling to find that whereinformation on the effects of stepwise covariate addition to models wasavailable in this article, that the same covariates were listed for both modelsbased on the stratification variable.There is excessive reliance onfractionation of the data set due to multiple stratification, sometimesreducing the number of subjects in a model to as few as 171. Even themodels using the most subjects had only 359 subjects. Lowpower to detectsignificant effects cautions againstany interpretation of non-significantresults. The time-integrated modelused 10 baseline blood pressuremeasurements and 5 follow up blood pressure measurements, thusweighting the avg toward baseline blood pressure. The entry of thebiochemical correlate of alcohol use in most of the models suggests that Pbeffects and Pb-containing alcohol effects on blood pressure were confused,especially given the European setting and the time period during which thestudy was conducted. Control for use of hypertensive medication rarelyentered models and partial control forthis variable was achieved only bystratified analyses, further reducing powerto detect significant effects in theremaining subgroup. No justificationwas given for stratified analyses.Incomplete information in statistical methods and results complicatesinterpretation. It was uncertain if stepwise regression was used for logisticmodels. No comparisons were performed to assess possible bias due tosubject attrition over the course of the study.

# AX6-153Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Staessen et al.(1996a) (cont’d)For the hypertension incidence model twodefinitions of hypertension were used:definite hypertension (systolic >160 mm Hg,diastolic >95 mm Hg or takingantihypertensive medications) and borderlinehypertension (systolic between 141 to159 mm Hg and diastolic between 91 to94 mm Hg). Method of covariate entry intohypertension incidence models not stated.Baseline natural log blood Pb was used as theexposure index.The over six decades of age representedin the sample was modeled by linear andquadratic terms based on age quintiles rather than continuous age, making it likelythat adequate control for age effects on blood pressure was not achieved and thatthe “healthy subject” effect seen in older groups was not controlled. If stepwiseaddition of significant covariates was used in the blood pressure difference models,were covariates in those models that were marked in the coefficient column asnon-significant not included in the models,and if that were so, it is unclear fromwhere the probability values that substitutefor the coefficients of those variableswere derived. There were no model diagnostic tests reported.Staessen et al.(1993)Belgium-CadmibelStudy1985-1989827 males and 821 females recruited from twoareas in Belgium, one of them surrounding anon-ferrous smelter, mean age (SD) 46 (15)and 44 (15) yrs, in men and womenrespectively. Subjects taking antihypertensivemedication were excluded from the analyses.Stepwise multiple regression models ofsystolic and diastolic blood pressure werestratified by sex. Covariates available forentry were age and age-squared, BMI, pulserate, log protoporphyrin, log gammaglutamyltranspeptidase, serum calcium, logserum ferritin, log serum creatinine, log serumzinc, urinary calcium, urinary sodium, andurinary potassium. Natural log blood Pb wasthe only variable forced into the models.Additional models tested the interaction ofserum calcium and blood Pb on bloodpressure.Geometric meanblood Pb (range),stratified by sex:Male blood Pb:10.4 μg/dL(2.7, 84.9)Female blood Pb:6.2 μg/dL (1.3, 42.4)In men, adjusting for age and age-squared, BMI, pulse rate, log gammaglutamyltranspeptidase, serum calcium,and log serum creatinine, every unitnatural log blood Pb increase was significantly associated with a -5.2 mm Hg (95%CI:!0.5,!9.9) decrease in systolic blood pressure. Natural log blood Pb was notsignificant in the model for diastolic blood pressure for men nor the systolic ordiastolic blood pressure for women.Adjusting for age and age-squared,BMI, pulse rate, and log gammaglutamyltranspeptidase, the interaction term between natural log blood Pb andserum calcium was only significant for systolic blood pressure in women. Everydoubling of blood Pb was associated with a 1.0 mm Hg decreasein systolic bloodpressure at serum calcium concentrationof 2.31 mmol/L (25th percentile) and anincreasein systolic blood pressure of 1.5 mm Hg at serum calcium concentrationof 2.42 mmol/L (75th percentile).Stepwise multiple regression analyses run risks of accepting chance associationsdue to multiple analyses of the same dataset. The role of alcohol use or alcoholuse markers in confounding Pb effect on bloodpressure in this setting has alreadybeen noted. The unexplained interaction between serum calcium and blood Pbhighlights the potential confounding roleof serum calcium with Pb in bloodpressure studies. The study shows graphs indicating distinct differences in the ageserum calcium and age-blood Pb relationships for men and women. From 50-70yrs of age serum calcium is higher than from≤29-49 yrs in women and

# AX6-154Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEurope(cont’d)Staessen et al.(1993) (cont’d)exceeds serum calcium of men at those older ages. The steepest rise inwomen’s blood Pb with age occurs between the 40-49 and 50-59 yr decades.The timing of these changes in women suggests that menopause may be afactor, which was accounted for only in the model for diastolic blood pressure.It also suggests that serum calcium level and age were also confounded in theblood pressure models. As serum creatinine clearance and blood Pb areinversely related, and serum creatinine is a significant covariate in the systolicblood pressure model for men with a significant negative bloodPb coefficient,it is possible that serum creatinine and blood Pb are confounded with bloodpressure in the men’s systolic blood pressure model. There were noassessments of subject selection bias due to exclusions. The authors noteexamining quintile blood pressure relationships with all covariates to determinethe acceptability of the linear relationship implied by the linear modelingtechnique. No other model diagnostic tests were reported.Telišman et al.(2004)Europe-CroatiaZagrebDate of datacollection notgiven.100 workers from factories producing Pbbased products, mean (range) age 30 (20-43)yrs. Exclusion criteria were absence ofpsychological stress (e.g., death in family)over last 4 mos, absence of verified diabetes,coronary heart disease, cerebrovascular andperipheral vascular disease, renal disease,hyperthyroidism, androgenital syndrome,primary aldosteronism, and “other diseasesthat could influence blood pressure or metalmetabolism.” Linear or natural log blood Pbwere considered for stepwise entry in modelsof systolic and diastolic blood pressure,forcing in all other covariates: bloodcadmium, BMI, age, serum zinc, serumcopper, hematocrit, smoking, and alcohol.Arithmetic mean(range) blood Pb:36.7 μg/dL(9.9-65.9)Neither linear nor natural log blood Pb entered as significant in multipleregression models of systolicand diastolic blood pressure.Very small sample sizelimited power todetect significant effects; nonsignificant effects should not be interpreted as lack of effect. Too manycovariates for a small study. Almost no subjects below 10 μg/dL. Takinghypertensive medications not controlled,likely a problem with top systolic anddiastolic blood pressure in the group 170 mm Hg and 110 mm Hg, respectively.No model diagnostic testing reported.

# AX6-155Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsiaLee et al. (2001)Korea-Chonan1997-1999798 workers from various Pb-using orproducing factories, mean (SD, range) age 40.5yrs (10.1) [17.8-64.8], 79.4% male, wereclassified as to Vitamin D receptor genotype(VDR bb or Bb/BB) and delta-aminolevulinicacid dehydratase (ALAD11 or 12) genotype, asVDR polymorphism has been implicated inmodifications of Pb absorption and Pb uptakeand release from bone as well as risk forelevated blood pressure and hypertension, andALAD polymorphism affects Pb binding to it inthe erythrocyte, the major storage depot of Pb inblood. The hypothesis was that polymorphismtype could influence the effect of Pb on bloodpressure and hypertension.Multiple linear regression models of linearblood Pb, DMSA-chelatable Pb, and tibia Pbeffect on systolic and diastolic blood pressurewith potential covariates of age and agesquared, sex, creatinine clearance, hemoglobin,weight, height, BMI, job duration, tobacco andalcohol consumption, pack-yrs of tobacco, andcumulative life time alcoholic drinks. Stepwiseprocedure allowed retention of covariates onlyif they were significant or “there weresubstantive changes in the coefficients ofpredictor variables after” their inclusion. In themodels shown, Appearance of multiple Pbvariables and the interaction between Pbvariables and genotype for each gene dependedupon the specific model. Both ALAD and VDRreceptor polymorphism were sometimes testedsimultaneously in each model containingpolymorphism termsand sometimes VDRappeared without ALAD.Arithmetic mean(SD, range) bloodPb: 32.0 μg/dL(15.0, 4-86)Mean (SD, range)DMSA-chelatablePb: 186 μg(208.4, 4.8-2103)Mean (SD, range)tibia Pb: 37.2 μg/g(40.4,!7 to 338)With simple t-tests, subjects with VDR Bb/BB allele were significantly older,had more DMSA-chelatable Pb, and hadhigher systolic and diastolic bloodpressure than subjects with VDR bb allele.In multiple regression models of systolic blood pressure, controlling for ageand age-squared, sex, BMI, antihypertensive medication use, and cumulativelife-time alcoholic drinks, adding tibiaPb, VDR type, and ALAD type, eachincrease of 10 μg/g of tibia Pb was associated with an increase of 0.24 mm Hg(95% CI:−0.01, 0.49) and VDR BB/Bb type was associated with an increaseof 3.24 mm Hg (95% CI: 0.18, 6.30) blood pressure compared to the VDR bbtype. ALAD genotype was not significant. In the same model, butsubstituting linear blood Pb for tibia Pb, each increase in 1 μg/dL of linearblood Pb was associated with an increase of 0.07 mm Hg (95% CI: 0.00,0.14) and VDR BB/Bb type was associated with an increase of 2.86 mm Hg(95% CI:!0.22, 5.94) blood pressure compared to the VDR bb type. ALADgenotype had no significant effects on blood pressure.When both tibia and linear blood Pbwere entered simultaneously along withVDR genotype, adjusting for the same covariates, only VDR Bb/BB wassignificant; compared to VDR bb, bloodpressure was 3.51 mm Hg (95% CI:2.41, 8.61) higher. ALAD genotypehad no significant effects on bloodpressure.In a model without any Pb terms, VDR genotype was interacted with the ageand the age-squared terms. The VDRBb/BB genotype interaction with thelinear age term was significant for systolic blood pressure. Compared withthe bb genotype the VDR Bb/BB genotypes’ blood pressure increased0.36 mm Hg (95% CI:0.06, 0.66) per yr faster with increasing age.There were no significant effects ofany Pb variable with diastolic bloodpressure, though the VDR Bb/BB genotype had significantly higher bloodpressure (1.9 mm Hg; not enough information given to calculate CI) than thebb genotypes.There were no significant interactions ofthe Pb measures with the genotypesfor either ALAD or VDR.

# AX6-156Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Lee et al. (2001)(cont’d)Logistic regression analysis was used to testthe effect of the Pb indices on hypertension(systolic >160 mm Hg or diastolic>96 mm Hg or taking antihypertensivemedications) using the same group ofpotential covariates, testing the Pb termsand the Pb-genotype interaction termsseparately. The hypertension models testedboth gene polymorphisms separately.Subjects with the Bb/BB genotypes had a significantly higher odds hypertensionprevalence (OR = 2.1 [95% CI: 1.0, 4.4]) than subjects with the bb genotype,adjusting for age, sex, BMI, tibia Pb, and current alcohol use. There were nosignificant effects of any Pb variablenor of ALAD on hypertension status.Linear blood Pb may not give efficient and unbiased estimates of blood Pb effect onblood pressure. The descriptive data shows highly skewed distributions for blood Pb,DMSA-chelatable Pb, and tibia Pb in this group, suggesting that coefficients of all Pbeffect on blood pressure may not have beenefficient and unbiased. Stepwise modelsusually produce different covariate patterns for different models, though the tablesindicate that the covariatesused for all the models discussed above were the same. Nomodel diagnostic tests were reported.Lustberg et al.(2004)Korea-Chonan1997-1999 (periodof enrollment; nostatement on datesof data collection)793 (number given for genotype analysis;numbers in models notgiven) current andformer Pb workers, mean (SD) age 40 (10)yrs and 80% male, were genotyped for thethree polymorphisms of endothelial nitricoxide synthase (eNOS)(GG, GT, TT), anenzyme that is a modulator of vascularresistance. The effect of genotype and theinteraction of genotype with blood Pb andtibia Pb on systolic and diastolic bloodpressure were evaluated by multiple linearregression analyses, forcing covariates ofage (modeled as a 2 degree of freedomspline with knot at 45 yrs), sex, natural logBMI, smoking and alcohol consumption,high school education, and job duration.Both blood Pb and tibia Pb were entered aspercentiles and entered together. Logisticmodels of hypertension (systolic∃140 mm Hg or diastolic∃90 mm Hg orreported use of antihypertensivemedication) used the same covariates.Interaction terms between each of the Pbmeasures (plus a Pb-squared term) andgenotype was used to determine differentialeffect of Pb according to genotype.Pb according togenotype:Arithmetic mean(SD) blood Pb, GG:32 (15) μg/dLArithmetic mean(SD) blood Pb,TG/TT: 32(15) μg/dLMean (SD) tibia Pb,GG: 37 (42) μg/gMean (SD) tibia Pb,TC/TT: 36 (34) μg/g85% (673/793) of the group were typed GG, 14% (114/793) were TG, and 1% (6/793)were TT. TG and TT groups were combined for analysis (TG/TT).Mean systolic and diastolic blood pressures, adjusted for all covariates, were notsignificantly different between GG and TG/TT groups.In multiple regression models for systolic anddiastolic blood pressure, neitherpercentile blood Pb nor percentile tibiaPb, entered together, were significantpredictors. Interaction terms betweenthe Pb variables and genotype were notsignificant.In the logistic regression model for hypertension, neither percentile blood Pb norpercentile tibia Pb, entered together, were significant predictors.Reporting was incomplete: number of subjectsentering the models was not stated; nocomparisons between recruited subjects and subjects not used in models. Despitereporting non-significant interactions, the paper showed both loess plots and tables ofanalyses stratified by genotype, reportingsignificant associations between both tibiaand blood Pb in the GG genotype, insignificant in the other. Inspection of the loessplots revealed striking non-linearity for bothadjusted blood Pb-systolic blood pressureand adjusted tibia Pb-systolic blood pressure relationships. Small group size of theTG/TT genotypes and highly unbalancedterms of the interaction may havecontributed to the non-significant interactions. Although the interaction Pb term wasalso probed as a quadratic function, the tibiaPb interaction was not, suggesting thatpoor concentration-response specification in the model mayalso have contributed tothe lack of significant main effects and interactions.

# AX6-157Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Nomiyama et al.(2002)China, BeijingNo statement ondates of datacollection123 female Pb-exposedleaded crystal toyworkers, mean age (range) 27.3 (17-44) yrs,and 70 female sewing workers (referencegroup), mean age (range) 24.2 (16-58) yrswere tested. Forward stepwise multipleregression models of systolic and diastolicblood pressure of the combined groupswere used with linear blood Pb and a set ofcovariates. Variables with p < 0.2 wereallowed to enter. The covariate set wasselected from a larger set of potentialcovariates by factor analysis, and arepresentative variable from each factorwas selected for possible entry in theregressions.Alternate models wereconstructed usingfour ordered categories of blood Pb, insteadof the linear continuous blood Pb variable.Logistic regressions were used to determinethe odds of elevated systolic (∃125 mm Hg)and elevated diastolic (∃80 mm Hg) bloodpressure as a function of blood Pb category.Blood Pb mean(SD, range) in Pbworkers: 55.4(13.5, 22.5-99.4 μg/dLBlood Pb mean(SD, range) in nonPb workers:6.4 (1.6, 3.8-11.4) μg/dLAdjusted for age, urine protein, and plasmatriglyceride, each 1 μg/dL increase inlinear blood Pb significantly associated with a 0.13 mm Hg increase in systolicblood pressure (no SE or CI given; p = 0.0003). Adjusted for plasma triglyceride,age, urine protein, plasma low density lipoprotein, and hypertension heredity, each1 μg/dL increase in linear blood Pb was associated with a 0.10 mm Hg increase indiastolic blood pressure (no SEor CI given; p = 0.0001).Using the ordered categories of blood Pb and the same covariates for systolic anddiastolic blood pressure, the 40-60 μg/dL group had 4.2 mm Hg (95% CI: 0.0, 8.5)higher systolic blood pressure and 4.1 mm Hg(95% CI: 1.3, 6.8) higher diastolicblood pressure than the reference group (blood Pb (<11.4 μg/dL). The group with∃60 μg/dL blood Pb had 7.5 mm Hg (95% CI:3.0, 12.0) systolic blood pressure and6.3 mm Hg (95% CI: 3.4, 9.1) diastolic blood pressure higher than the referencegroup.Logistic regression modelsfor “elevated” blood pressure, modeled using the samecovariates were similar. In the 40-60 μg/dL group odds of systolic blood pressure∃125 mm Hg and diastolic blood pressure∃80 mm Hg were 4.26 (95% CI: 1.07,17.04) and 2.43 (95% CI: 0.97, 6.04), respectively, higher than the reference group.The odds of “elevated” systolic and diastolic blood pressure in the group with bloodPb∃60 μg/dL were 7.48 (95% CI: 1.86, 30.12) and 3.31 (95% CI: 1.29, 8.50),respectively.Incomplete reporting in paper: no modelN, no SEs for linear blood Pb regressions,no description of type of factor analysis used or dates of data collection. Innovativeuse of factor analysis to select covariatesthat, depending on howthe factor analysiswas run, could have produced a set oforthogonal variables for model entry.However, BMI was not included in the original set of covariates or in the models.Small sample size limits conclusions based on nonsignificant results. Stepwiseregression produced a different covariatepattern for each component of bloodpressure. The linear blood Pb variable may be inappropriate given the markedskewness of blood Pb in descriptive analysis. The 11 μg/dL gap in blood Pbbetween Pb workers and non-Pb workers could have introduced problems inanalyses with continuous blood Pb. Larger age spread in non-exposed group than inexposed group could have caused misspecification of age variable. No control forantihypertensive medication use. No model diagnostics reported.

# AX6-158Table AX6-5.1 (cont’d). Effects of Leadon Blood Pressure and HypertensionReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationAsia(cont’d)Wu et al. (1996)Central TaiwanNo statement ondates of datacollection222 workers in two Pb battery plants, 112men, mean (range) age 36.2 (18-67) yrs, and110 women, mean (range) age 36.2 (18-71)yrs were tested for blood Pb relationshipswith systolic and diastolic blood pressure inmultiple regression models, using a fixed,forced set of covariates: age, sex, BMI,working history, yrs of work, noise exposure,natural log ambient air Pb concentration, andordered categorical bloodPb concentration.Arithmetic mean (SD,range) blood Pb:Women: 44.6 (18.4,8.3-103.1) μg/dLMen: 60.2 (26.8,17.0-150.4) μg/dLUsing four ordered blood Pb categories (<25 μg/dL [n = 16/222; 6.8%], 25-40 μg/dL [58/222; 26.1%], 41-60 μg/dL [63/222; 27.9%], and >60 μg/dL[85/222; 38.3%]) adjusted systolic and diastolic blood pressure were notsignificantly related to the top three blood Pb categories compared to thelowest, natural log ambient Pb. Yrs in work environment was a significantpredictor of both systolic and diastolic blood pressure, but age was onlymarginally significant for systolic blood pressure and not significant fordiastolic blood pressure.Small study size limits any conclusionsdrawn from non-significant results.Three measures, all related to Pb exposure, were simultaneously tested in themodels. While blood Pb may only be weakly correlated with yrs of work,ambient air Pb would be expected to be much better correlated with blood Pb.There is a clear possibility of collinearity among those three variables, whichwould inflate standard errors and reduce coefficients. Authors selectedordered categories of Pb to “avoid unnecessary assumption of linearity.” Theuse of natural log air Pb concentration suggests that some diagnostics wererun, but no model diagnostic tests were reported. No control forantihypertensive medication use.

# AX6-159Table AX6-5.2. Effects of Lead on Cardiovascular MorbidityReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited StatesCheng et al.(1998)U.S.-Boston,Normative AgingStudy (VA)1991-1995775 males (97% white), mean age (SD,range) 67.8 yrs (7.3, 48-93).Multiple linear regression models ofheart rate-corrected QT and QRSelectrocardiogram intervals wereadjusted by stepwise entry ofcovariates, retaining only those thatremained significant at p < 0.10.Linear blood Pb, tibia, and patella bonePb were apparently (not described intext) entered separately. Logisticregression models for Minnesota ECGCoding Center diagnoses ofintraventricular conduction deficit(IVCD), atrioventricular conductiondeficit (AVCD), and arrhythmia wereadjusted by covariates the same way.Only analyses stratified by age (<65yrs, n = 277;∃65 yrs, n = 498) werepresentedArithmetic mean (SD)blood Pb: 5.8 μg/dL (3.4)Mean (SD) tibia Pb:22.2 μg/g (13.4)Mean (SD) patella Pb:30.8 μg/g (19.2)Multiple regression models of QT intervals, adjusted for age, alcohol intake,BMI, and diastolic blood pressure, foundthat only tibia and patella Pb weresignificantly related to outcome in the under 65 group. Every 10 μg/g increase oftibia and patella Pb was associated with a 5.0 ms (95% CI: 0.8, 9.2) and 3.0 ms(95% CI: 0.2, 5.8) increase in QT interval, respectively. Multiple regressionmodels of QRS intervals, adjusted for age, fasting glucose level, and diastolicblood pressure, also found that only tibia and patella Pb were significantly relatedto outcome in the under 65 group. Every 10 μg/g increase of tibia and patella Pbwas associated with a 4.8 ms (95% CI: 1.8, 7.8) and 2.2 ms (95% CI: 0.1, 4.4)increase in QRS interval, respectively. There were no significant effects of Pb inthe 65 and over group.Logistic regression models of IVCD, adjusted for age and serum HDL level,found that only tibia Pb was significantly related to outcome in the under65 group. Every 10 μg/g increase of tibia Pb was associated with increased oddsof IVCD, OR = 2.23 (95% CI: 1.28, 3.90). There were no significant Pb effectsin the 65 and over group for IVCD. Logistic regression models of AVCD,adjusted for age and serum HDL level, found that both tibia and patella Pb weresignificantly related to outcome in the 65 and over group. Every 10 μg/gincrease of tibia Pb and patella Pb was associated with increased odds of AVCD,OR = 1.22 (95% CI: 1.02, 1.47) and OR = 1.14 (95% CI: 1.00, 1.29),respectively. Pb was not significantlyrelated to AVCD in the under 65 group.There were no significant effects of Pbon arrhythmia in either age group.Stepwise models may capitalize on chance associations.Linear blood Pbspecification may not be appropriate in someor all of these models. Not clear ifthree models were constructed for each stratified analysis for each outcome, eachbased on a different Pb index. No statistical comparisons across strata. Nomodel diagnostics were presented.Gump et al. (2005)U.S.-Oswego, NYDates of study notgivenSee Gump et al. (2005) entry in BloodPressure and Hypertension section forheart rate, stroke volume, cardiacoutput, total peripheral resistance, andcardiac interbeat interval data.

# AX6-160Table AX6-5.2 (cont’d). Effects ofLead on Cardiovascular MorbidityReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Navas-Acien(2004)U.S.-NHANESIV-Phase 11999-20002125 subjects (1070 males, 1055females), age 40->70 yrs were testedfor peripheral arterial disease (PAD;n = 139) by taking the ratio of theankle mean systolic blood pressure tothe arm mean systolic blood pressure.Any subject with the ratio <0.90 wasclassified as PAD. Logistic regressionanalysis was weighted and adjusted bysample design. Covariates forced intothe models were age, sex, race,education, and Pbquartile (Model 1);Model 1 covariates plus BMI, alcoholintake, hypertension, diabetes,hypercholesterolemia, glomerularfiltration rate, and C-reactive protein(Model 2); Model 2 covariates plusself-reported smokingstatus and serumcotinine (Model 3); and Model 3covariates plus cadmium quartile(Model 4). Tested interactionsbetween Pb and cadmium on PAD,and between Pb and sex, race, smokingstatus, renal function, and c-reactiveprotein on PAD. Tested for trend ofOR as a function of Pb quartile.Geometric mean blood Pb(25th-75th percentile):2.1 μg/dL (1.4, 2.9)Pb quartile 1: <1.4 μg/dLPb quartile 2:1.4-2.1 μg/dLPb quartile 3:2.1-2.9 μg/dLPb quartile 4: >2.9 μg/dLOdds for PAD significantly increased with Pb quartile (1st quartile used ascomparison) for all four models. Onlymodels 1 and 2,however, showed asignificant increase in odds of PAD for the 4th Pb quartile compared to the 1st Pbquartile, OR = 3.78 (95% CI: 1.08, 13.19) and OR = 4.07 (95% CI: 1.21, 13.73).None of the tested interactions with blood Pb quartile were significant.Well-designed study with sound statisticalanalysis. Including two variables forsmoking in Models 3 and 4 (smoking status and cotinine) may have overcontrolled for smoking). There was a trend toward increased blood Pb level withincreased smoking status and with increasedcotinine levels,though no statisticaltests of trend were reported. Thus the two smoking variables and Pb may havebeen confounded with PAD. No model diagnostic tests reported.Schwartz (1991)NHANES IIU.S.1976-1980See Schwartz (1991) entry in BloodPressure and Hypertension for leftventricular hypertrophy results.

# AX6-161Table AX6-5.2 (cont’d). Effects ofLead on Cardiovascular MorbidityReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Tepper et al.(2001)U.S.-Cincinnati,OHAfter 1991 tobefore 2001See Tepper et al. (2001) entry in BloodPressure and Hypertension for leftventricular mass results.EuropeGustavsson et al.(2001)Europe-Stockholm,Sweden1992-1994Study base was all Swedish citizens45-70 yrs old from Stockholm Countyfree of previous myocardial infarction.Cases who survived at least 28 daysafter infarct (1,105 males and 538females) of which 937 men (85%) and398 women (74%) had sufficientinformation on occupational exposuresand “main confounders”, werecompared against referents (1,120 menand 538 women) matched to cases bysex, age, yr, and hospital catchmentarea. Risk ratios for the case groupcompared to referent group wereadjusted on the basis of the matchingvariables and smoking, alcoholdrinking, hypertension, overweight,diabetes mellitus, leisure physical“inactivity”, and were calculated for anumber of exposure factors separately,including Pb.Pb exposure wasclassified as none, low orhigh corresponding toairborne dust levels of 0,>0 to 0.03, and∃0.04 mg/m3,respectively, for thehighest intensity ofexposure during at leastone yr of work. The samethree classifications wereused for 0, >0 to 0.04, and∃0.05 mg/m3forcumulative exposure.All risk ratios were calculated relative to the “no exposure” groups. Adjustedrisk ratios for surviving a myocardialinfarction were 0.88 (95% CI: 0.69, 1.12)and 1.03 (95% CI: 0.64, 1.65) for low and high exposure groups for peak Pbexposure, and were 0.81 (95% CI: 0.60, 1.11) and 1.00 (0.74, 1.34) for the lowand high cumulative exposure groups.This study of myocardial morbidity was compromised by poor Pb exposurecharacterization (occupational air dust Pb concentration) and by including acovariate collinear with Pb exposure and confounded with the outcome,hypertension, in the adjusted models.No model diagnostics were reported.

# AX6-162Table AX6-5.3. Effects of Lead on Cardiovascular MortalityReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited StatesLustberg andSilbergeld (2002)U.S.-NHANES II1976-1980,follow up to 19924190 persons, 30 to 74 yrs, 929 of whomdied during follow up, had baseline blood Pbmeasurements during the NHANES IIperiod. Proportional hazard models forcirculatory disease-related death (ICD-9codes 390-459) were based on the complexsurvey design, but not weighted. Presentedmodels were unadjusted, adjusted for ageand sex, and adjusted for age, sex, location,education, race, income, smoking, BMI, andexercise. Blood Pb was entered as anordinal three-category variable.Blood Pb <10 μg/dL,n = 818Blood Pb 10-19 μg/dL,n = 2735Blood Pb 20-29 μg/dL,n = 637Blood Pb∃30 μg/dL,n = 102, excluded fromanalysisCrude, sex and age adjusted, and multivariate adjusted circulatory diseasemortality were all significantly increased in the 20-29 μg/dL group comparedto the <10 μg/dL reference group. Risk ratio for the highest Pb group forcrude circulatory mortality was 1.74 (95% CI: 1.25, 2.40), for age and sexadjusted circulatory mortality was 1.48 (95% CI: 1.10, 2.01), and formultivariate circulatory mortality was 1.39 (95% CI: 1.01, 1.91).Stratified analyses were performed by race, sex, age, smoking, education, etc.,but only for all-cause mortality.No model diagnostics reported.Schober et al.(2006)U.S.-NHANESIII1988-1994,follow up to 20009757 persons, age 40 yrs, 2515 of whomdied during follow-up (median length offollow-up 8.55 yrs), had baseline blood Pbmeasurements during the NHANES IIIperiod. Analyses were performed usingproportional hazard models for all causedeaths, major cardiovascular disease-relateddeaths (I00-I78), and malignant neoplasms(C00-C97). Multivariate models wereadjusted for sex, race/ethnicity, education,and smoking status and stratified by age.Blood Pb was entered as an ordinal threecategory variable.Blood Pb <5 μg/dL(median 2.6 μg/dL),n = 6608Blood Pb 5-9 μg/dL(median 6.3 μg/dL),n = 2532Blood Pb 10 μg/dL(median 11.8 μg/dL),n = 617Multivariate-adjusted cardiovascular disease mortality was significantlyincreased in the 10 μg/dL group compared to the <5 μg/dL reference group.All cause and cancer mortalities were significantly increased in the 5-9 μg/dLand 10 μg/dL groups.Relative risk for cardiovascular disease mortality, compared to <5 μg/dL:5-9 μg/dL: 1.20 (95% CI: 0.93, 1.55)10 μg/dL: 1.55 (95% CI: 1.16, 2.07)Relative risk for all cause mortality, compared to <5 μg/dL:5-9 μg/dL: 1.24 (95% CI: 1.05, 1.48)10 μg/dL: 1.59 (95% CI: 1.28, 1.98)Relative risk for cancer mortality, compared to <5 μg/dL:5-9 μg/dL: 1.44 (95% CI: 1.12, 1.86)10 μg/dL: 1.69 (95% CI: 1.14, 2.52)Tests for trends were statistically significant for all three mortality groups.

# AX6-163Table AX6-5.3 (cont’d). Effects ofLead on Cardiovascular MortalityReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Michaels et al.(1991)U.S.-New YorkCity1961-19841261 males, avg age (range) at thebeginning of study 49.6 yrs (19-83),representing 24,473 person-yrs werefollowed. 498 died in the interval.Subjects belonged to the InternationalTypographical Union and worked at twolarge city newspapers. Hot Pb linotypingwas discontinued at the newspapersduring 1974-1978, providing the primarysource of occupational exposure. Lastexposure for all subjects still employedwas at the end of 1976.Standardized mortality ratios (SMR)were calculated using the LTAS programdeveloped by NIOSH, calculating theexpected number of deaths of the cohortreferenced to a comparison population, inthis case disease-specific mortality ratesfrom New York City. Cohort wasstratified based on yrs of employment.Causes of death were based on ICD-8codes.Exposure was estimatedbased on yrs of linotypeemployment before theend of 1976. Authorsnote that, based onmeasurements at otherprint shops using hot Pblinotype, air Pb levelsprobably did not exceed20 μg/m3.Standardized mortality ratio was significant (SMR = 1.68 [95% CI: 1.18, 2.31])only for cerebrovascular disease in thoseworking, and thus exposed, for 30 yrsor more. Neither arteriosclerotic heart disease (ICD-8 410-414) nor vascularlesions of the central nervous system(ICD-8 430-438) had significant SMR inthe total cohort not stratified by yrs of exposure.No direct measurement of Pb exposure.Many groupings of ICD codes wereexplored in stratified and unstratified analyses, with the only significantlyelevated SMR found for cerebrovascular disease. No a priori hypotheses.General weakness of all studies relying on a comparison population is that thecohort belongs to the comparison population and can influence the comparisonmortality rates in direct proportion tothe ratio between cohort and comparisonpopulation size.

# AX6-164Table AX6-5.3 (cont’d). Effects ofLead on Cardiovascular MortalityReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationUnited States(cont’d)Steenland et al.(1992)U.S.-Idaho>1941 to 1988The death certificatesof 1028 males ofthe 1990 who worked at a smelter plantat least one yr between 1940 and 1965were examined to construct standardizedmortality ratios (SMR) for various ICD-9disease classifications using the U.S.population as a referent group.In 1976 blood Pb of173 workers avgd (SD)56.3 μg/dL (12.9). AirPb was measured in1975 at 3.1 mg/m3in208 personal 8-hsamples. High Pbdepartments in the plantwere defined as thoseexceeding 0.2 mg/m3inthe 1975 survey.Non-malignant respiratory disease andaccidents accounted for most of thesignificantly elevated SMR in the group.SMRs were not significantly elevatedfor ischemic heart disease (410-414), SMR = 0.94 (95% CI: 0.84, 1.05);hypertension with heart disease (402, 404), SMR = 0.97 (95% CI: 0.53, 1.63);hypertension with no heart disease (401,403, 405), SMR = 1.73 (95% CI: 0.63,3.77); or cerebrovascular diseases (430-436), SMR = 1.05 (95% CI: 0.82, 1.32).Similar results were found for the peopleworking in the “high Pb departments.”Though there is no doubt that this group was highly exposed to Pb, exposurecharacterization over the working lifetime was not well defined, few blood Pbdata were available, and poor demographic datafor the exposed group onlyallowed a comparison with total U.S. population. As is usual with occupationallyexposed groups, selection bias may influence results. No smoking data wereavailable for the group. In industrial conditions smoking will be confoundedwith other Pb exposure (constant hand tomouth behavior on the plant floor willexposure smokers to more Pb via theoral route than in non-smokers).

# AX6-165Table AX6-5.3 (cont’d). Effects ofLead on Cardiovascular MortalityReference, StudyLocation, andPeriod Study Description Pb Measurement Findings, InterpretationEuropeGerhardsson et al.(1995)Europe-southernSweden1969-1989664 male workers at a secondary Pbsmelter had blood Pb tested every 2-3mos since 1969. The past blood Pb levelof 201 workers who had been working atthe plant from before 1969 was estimatedfrom their 1969 results. Median (10thpercentile, 90th percentile) yr of birthwas 1943 (1918, 1960). Median (10thpercentile, 90th percentile) duration ofemployment was 2.8 yrs (0.3, 25.7) andmedian (10th percentile, 90th percentile)duration of follow up was 13.8 yrs (2.8,20.9). A total of 8706 person-yrs wererepresented in the study. Standardizedmortality ratios based on countymortality tables by calendar yr, cause,sex and five-yr age group werecalculated. Cardiovascular diseases werecoded by ICD-8 from death certificates.Arithmetic mean bloodPb levels dropped from~62 μg/dL in 1969 to~33 μg/dL in 1985.95% CI were difficultto extract from thepresented graph, butappeared to be no morethan 5-6 μg/dL aboutthe mean.All cardiovascular diseasemortality (ICD-8 390-458) was significantly elevatedabove that expected from the county mortality tables (SMR = 1.46 [95% CI:1.05, 2.02]), with 39 of the 85 deaths observed in the cohort. For just ischemicheart disease (ICD-8 410-414), SMR = 1.72 (95% CI: 1.20, 2.42) in the plantworkers with 34 of the 85 deaths observed in the cohort. There were no deathsrecorded for cerebrovascular diseases (ICD-9 430-438). There was no apparentconcentration-response relationship, using peak blood Pb and time-integratedblood Pb.Problems inherent in using standardized mortality ratios in such mortality studieshave been discussed above. The samplesize was too small (85 all cause deathsamong 664 workers) to interpret non-significant results.Møller andKristensen (1992)Europe-DenmarkCopenhagenCounty-GlostrupPopulation Studies1976-1990See Møller et al. (1992) entry in BloodPressure and Hypertension for results ofcardiovascular disease and coronary heartdisease mortality.

# AX6-166Table AX6-5.4. Cardiovascular Effects of Lead on ChildrenReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings, InterpretationUnited StatesChen et al. (2006)U.S.-Baltimore, MD;Cincinnati, OH;Newark, NJ;Philadelphia, PA~1998-2004780 children from 12-33 mos participatedin a randomized clinical trial of oralsuccimer chelation in four clinicalcenters. Half the children had up to three26-day treatments, the other half weregiven placebo. 75% got two treatmentsessions and 81% of those with twotreatments received a third.Blood pressure was measured pre-treatment, at 7, 28, and 42 days after eachtreatment, then every 3 to 4 mos for fiveyrs of follow up. Cross-sectionalmultiple regression models adjusting forclinic location, baseline linear Pb, race,sex, parents’ education, single parent, ageat test, height at test, and BMI at test foreach period of the study tested thedifference of diastolic and systolic bloodpressure between placebo and succimergroups. Cross-sectional multipleregression models forthe effect of linearblood Pb at each period on bloodpressure adjusted for clinic location,treatment group, race, sex, parents’education, single parent, age at test,height and BMI.Two mixed models,one from start of treatment to 9-mofollow up, the other from 12 to 60 mosfollow up, adjusted for the samevariables, and tested the effect oftreatment group over time.Blood Pb ranged from20-44 μg/dL at pre-treatmentand from 1-27 μg/dL at 5 yrfollow up. Succimer-treatedgroup had significantlylower blood Pb than placebogroup only for 9-10 mosfollowing the end oftreatment. Blood Pb did notdiffer significantly beyondthat period.Adjusted systolic blood pressure was significantly higher in the succimergroup than the placebo group at 36 mos (1.27 mm Hg [95% CI: 0.06,2.48]) and at 60 mos follow up (1.69 mm Hg [95% CI: 0.34, 3.04]).Systolic blood pressure was not significantly different at any other timeperiod; diastolic blood pressure wasnever significantly different betweengroups.Concurrent linear blood Pb was not associated with blood pressure incross-sectional models at any timepoint in the study. Adjustedcoefficients for linear blood Pb and systolic blood pressure ranged from1.36 mm Hg (95% CI:!0.58, 3.30) at pre-treatment to!0.72 mm Hg (95%CI:!1.91, 0.48) at 36 mos of follow up.Diastolic pressure coefficientswere generally lower but followed the same pattern.Mixed model analysis for start of treatment through 9 mos follow upshowed succimer treatment effect of 0.24 mm Hg (95% CI:!0.79, 1.28)for systolic and 0.46 mm Hg (95% CI:!0.44, 1.36) for diastolic bloodpressure. The treatment effect from 12 through 60 mos follow up was1.09 mm Hg (95% CI: 0.27, 1.90) systolic and 0.15 mm Hg (95% CI:!0.45, 0.75) for diastolic blood pressure.The only reliable effect of succimer treatment was an elevation of systolicblood pressure, especially notablebetween three and five yrs posttreatment. The authors could notaccount for the apparent increase inblood pressure in the succimer-treatedgroup 3-5 yrs after treatment ended.It is notable that thetwo groups had different mean blood Pb for less thana yr after succimer treatment ended, a period perhaps too short to observeany beneficial effect of treatment. Failure to find cross-sectional effects ofblood Pb on blood pressure, especiallypre-treatment, may indicate that Pbexposure for a period of less than threeyrs after birth is not sufficient toaffect blood pressure or that blood pressure measurements in the first threeyrs of life are highly variable, as could be seen from scatter plots of bloodpressure vs. blood Pb at pre-treatment compared 60 mo follow up. Theuse of linear Pb term may have reduced sensitivityto finding a significantblood Pb effect on blood pressure.No model diagnostics mentioned.

# AX6-167Table AX6-5.4 (cont’d). Cardiovascular Effects of Lead on ChildrenReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited States(cont’d)Gump et al. (2005)U.S.-Oswego, NYDates of study notgiven122 9.5-yr old children participated.Multiple regression models of percentchanges in systolic and diastolic bloodpressure, heart rate, stroke volume,cardiac output, andtotal peripheralresistance due to acute stress wereadjusted by stepwise entry of up to50 possible control variables withquartile blood Pb forced in last. A linearcontrast was used to test dose-responseeffects of quartile Pb. Linear Pb termswere also used.Contemporary blood Pbquartile:1st quartile: 1.5-2.8 μg/dL2nd quartile: 2.9-4.1 μg/dL3rd quartile: 4.2-5.4 μg/dL4th quartile: 5.5-13.1 μg/dLAll∃represent percent change in outcome from nonstress to stresscondition for each change in 1 μg/dL blood Pb.Systolic blood pressure:∃=!0.009 (95% CI:!0.74, 0.055)Diastolic blood pressure:∃= 0.069 (95% CI:!0.001, 0.138)Heart rate:∃= 0.013 (95% CI:!0.046, 0.072)Stroke volume:∃=!0.069 (95% CI:!0.124,!0.015)Cardiac output:∃=!0.056 (95% CI:!0.113, 0.001)Total peripheral resistance:∃= 0.088 (95% CI: 0.024, 0.152)Mean successive difference ofcardiac interbeat interval:∃=!0.028 (95% CI: (!0.098, 0.042)Despite low power to detect significant effects, blood pressure, cardiacoutput, and total peripheral resistance change to stress were associatedwith contemporary blood Pb. Stepwise modeling creates uniquemodels for each outcome. Some models had up to 12 control variablesplus Pb, an excessive number for only 122 subjects. Scatter plots ofregression with linear Pb and barcharts of response to quartile Pbshowed obvious non-linearity, though all Pb effects were modeled aslinear effects. Probability of contemporary exposure to mercury andPCB’s was very high. No model diagnostic testing reported.EuropeFactor-Litvak et al.(1996)Europe-KosovskaMitrovica and Pristina,Kosovo~1992-1993281 5.5-yr old children studied sincepregnancy participated. Multiple linearregression models of systolic bloodpressure, adjusted for height, BMI,gender, ethnic group, and birth order, anddiastolic blood pressure, adjusted forwaist circumference, ethnic group, andbirth order were constructed by stepwiseelimination from a larger pool ofpotential confounding variables andretained if they modified the linear bloodPb coefficient by more the 10%.Blood Pb arithmetic mean(range):22.7 μg/dL (5-55)For each increase of 1 μg/dL of blood Pb:Systolic blood pressure:∃= 0.054 (95% CI:!0.024, 0.13)Diastolic blood pressure:∃= 0.042 (95% CI:!0.01, 0.090)Despite low power to detect significant effects, there was a marginallysignificant tendency for blood pressureto be positivelyassociated withblood Pb. Stepwise multiple regression may have capitalized onchance results. The linear Pb term may have reduced the ability todetect significant effects of Pbif the modeled relationship werenonlinear. Log Pb was tested but notreported. A quadratic Pb termwas reported nonsignificant. No model diagnostics reported.

# AX6-168 

# ANNEX TABLES AX6-6

# AX6-169Table AX6-6.1. Placental Transfer of Lead from Mother to FetusReference andStudy LocationStudy Description Pb Measurement Findings, InterpretationUnited StatesHarville et al. (2005)Pittsburgh, PA159 mother-infant pairs. Maternal blood Pb at delivery:Mean 1.93 μg/dL (range 0.55-4.70)Cord blood Pb:Mean 1.64 μg/dL (range 0.05-3.95)Correlation coefficient = 0.79On avg, cord blood Pb was lower than maternalblood Pb by 0.03 μg/dL (95% CI: 0.21, 0.38).Angell and Lavery(1982)Louisville, KY635 cord blood specimens. 154 maternaland infant blood samples collected 24 hpostpartum from these deliveries.Maternal blood Pb:Mean 9.85 μg/dL (SD 4.4)Infant blood Pb:Mean 9.82 μg/dL (SD 4.8)Cord blood Pb:Mean 9.78 μg/dL (SD 4.1)Maternal-infant blood Pb:Correlation coefficient = 0.73,∃= 0.73Maternal-cord blood Pb:Correlation coefficient = 0.60,∃= 0.55Cord-infant blood Pb:Correlation coefficient = 0.77,∃= 0.90Bogden et al. (1978)Newark, NJ25 deliveries of infants with birth weightsbetween 1,500-2,500g and 50 matchedcontrols with birth weights above 2,500g.Low birth weight infants:Maternal blood Pb:Mean 16.2 μg/dL (SD 4.5)Cord blood Pb:Mean 13.8 μg/dL (SD 4.4)Normal birth weight infants:Maternal blood Pb:Mean 15.3 μg/dL (SD 5.2)Cord blood Pb:Mean 13.1 μg/dL (SD 4.3)No significant differencesin maternal blood tocord blood ratios in low birth weight and normalbirth weight infants.Correlation coefficient = 0.55

# AX6-170Table AX6-6.1 (cont’d). Placental Transfer of Lead from Mother to FetusReference andStudy LocationStudy Description Pb Measurement Findings, InterpretationUnited States(cont’d)Fahim et al. (1976)Missouri249 mother-infant pairs from Columbia.Samples also collected from 253 mothersfrom Rolla who delivered near Pb miningareas.Term pregnancies:Columbia (n = 240):Maternal blood Pb:Mean 13.1 μg/100 g (SE 0.31)Fetal blood Pb:Mean 4.3 μg/100 g (SE 0.10)Placenta blood Pb:Mean 7.0 μg/100 g (SE 0.01)Cord blood Pb:Mean 11.0 μg/100 g (SE 0.31)Rolla (n = 177):Maternal blood Pb:Mean 14.3 μg/100 g (SE 0.16)Fetal blood Pb:Mean 4.6 μg/100 g (SE 0.08)Placenta blood Pb:Mean 8.0 μg/100 g (SE 0.06)Cord blood Pb:Mean 11.0 μg/100 g (SE 0.14)Maternal-fetal blood Pb:Correlation coefficient = 0.29

# AX6-171Table AX6-6.1 (cont’d). Placental Transfer of Lead from Mother to FetusReference andStudy LocationStudy Description Pb Measurement Findings, InterpretationUnited States(cont’d)Gershanik et al.(1974)Shreveport, LA98 mother-infant pairs. Maternal blood Pb during labor:Mean 10.3 μg/dLCord blood Pb:Mean 10.1 μg/dLCorrelation coefficient = 0.64EuropeGraziano et al.(1990)Kosovo, Yugoslavia902 births in Titova Mitrovica, site of alarge Pb smelter, refinery, and batteryfactory, and Pristina, a non-Pb-exposedcontrol town.Maternal blood Pb at mid-pregnancy:Geometric means:Titova Mitrovica 17.1 μg/dL (95% CI:16.9, 42.6)Pristina 5.1 μg/dL (95% CI: 2.5, 10.6)Maternal blood Pb at delivery and cordblood Pb:Correlation coefficient = 0.920,∃= 0.928Huel et al. (1981)FranceHair sample pairs (n = 100) from mothersand newborns at time of delivery.Maternal hair Pb:Geometric mean 8.5 μg/dLFetal hair Pb:Geometric mean 7.3 μg/dLCorrelation coefficient = 0.24Lauwerys et al.(1978); Roels et al.(1978) Belgium474 mother-infant pairs from Antwerp,Brussels, Leuven, Tournai, and Vilvoorde.Maternal blood Pb:Mean 10.1 μg/dL (range 3.1-31)Infant blood Pb:Mean 8.3 μg/dL (range 2.7-27.3)Placenta blood Pb:Median 7.5 μg/100 g wet weight (range 1.1-39.5)Maternal-infant blood Pb:Correlation coefficient = 0.81,∃= 0.73ln placenta-maternal blood Pb:Correlation coefficient = 0.22ln placenta-infant blood Pb:Correlation coefficient = 0.28Barltrop (1969)England29 paired maternal and fetalsamples. Maternal blood Pb:Mean 13.9 μg/100 gCord blood Pb:Mean 10.8 μg/100 gCorrelation coefficient = 0.86

# AX172Table AX6-6.1 (cont’d). Placental Transfer of Lead from Mother to FetusReference andStudy LocationStudy Description Pb Measurement Findings, InterpretationEurope(cont’d)Barltrop (1969)England34 fetuses at gestational age 10 to 40 wksobtained from termination of pregnancy andneonatal deaths.Blood Pb levels in femur, liver, blood, brain, heart,and kidney measured.Pb became detectable at gestational age 12 -14wks. For skeletal (femur) and soft tissue withhigh affinity (liver), Pb levels increasedprogressively until term. In contrast, in softtissue with low affinity (heart), only a modestincrease in Pb levels was observed between 14wks and term.Latin AmericaChuang et al. (2001)Mexico City, Mexico615 women recruited in 1994-1995.Investigators used structural equationmodeling to estimate plasma Pb as theunmeasured variable and to quantify theinterrelations of cord blood Pb with plasmaPb, whole blood Pb, and bone Pb (corticaland trabecular).Maternal whole blood Pb:Mean 8.45 μg/dL (SD 3.94)Maternal patella bone Pb:Mean 14.24 μg/g bone mineral (SD 14.19)Maternal tibia bone Pb:Mean 9.67 μg/g bone mineral (SD 9.21)Cord blood Pb:Mean 6.55 μg/dL (SD 3.45)ln cord-ln maternal whole blood Pb:Correlation coefficient = 0.82ln cord-ln maternal plasma Pb:Correlation coefficient = 0.89ln cord-maternal patella Pb:Correlation coefficient = 0.23ln cord-maternal tibia Pb:Correlation coefficient 0.18The structural equation models indicated thatmaternal plasma Pb had a stronger associationwith fetal cord blood Pb compared to that ofwhole blood Pb. In addition, the modelssuggested a significant contribution of Pb fromthe skeletal system toplasma during pregnancy,a contribution that is independent of theinfluence of maternal whole blood Pb.

# AX6-173Table AX6-6.1 (cont’d). Placental Transfer of Lead from Mother to FetusReference andStudy LocationStudy Description Pb Measurement Findings, InterpretationOther LocationsClark (1977)Zambia122 mother-infant pairs residing near theBroken Hill Pb Mine and Smelter. Controlgroup of 31 mother-infant pairs.Mine group:Maternal blood Pb:Mean 41.2 μg/dL (SD 14.4)Infant cord blood Pb:Mean 37.0 μg/dL (SD 15.3)Control group:Maternal blood Pb:Mean 14.7 μg/dL (SD 7.5)Infant cord blood Pb:Mean 11.8 μg/dL (SD 5.6)Mine group:Correlation coefficient = 0.77Control group:Correlation coefficient = 0.56Casey and Robinson(1978)New Zealand40 fetuses (23 stillborn and 17 died within24 hrs), 22 to 43 wks gestation.Pb detected in 73% of liver, 23% of kidneys, 40%of brain, 25% of heart, 33% skeletal muscle, and70% of bone samples. Pb also detected in 11 of 14lung samples (79%).Overall Pb concentration in soft tissue:0.1-2.4 μg/g dry matterPb concentration in bone samples:0.4-4.3 μg/g dry matterPb concentrations in bonewere higher than inthe other tissues.Levels in brain, heart, and muscle similar tovalues reported for children and adults. Levelsin liver, kidney, lung, and bone were much lessthan adult values, suggesting much of the Pb thatenters the body after birth accumulates in thesetissues.Chaube et al. (1972) 50 embryos and fetuses 31 to 261 daysgestational age that were aborted.Among the 1st trimester specimens:Pb detected in 77% of liver, 15% of brain, and 30%of kidney samples.Placental transfer occurs as early as the 1sttrimester of pregnancy.

# AX6-174Table AX6-6.2. Lead Exposure and Male Reproduction: Semen QualityReference andStudy LocationStudy Description Pb Measurement Findings, InterpretationUnited StatesBenoff et al. (2003a)New York74 male partners of women undergoingtheir first in vitro fertilization cycle.Seminal plasma Pb:Mean 39.50 μg/dL (SD 35.97)Significant negative correlation between seminalplasma Pb and fertilization rate (r =!0.447).Statistically significant inverse correlations (rvalues of <!0.3) were found between seminalplasma Pb levels and sperm count, motility, andmorphology. Stronger negative relationshipswere observed between seminal plasma Pbvalues and mannose receptor expression (r =!0.383), and mannose-stimulated acrosome loss(r =!0.423).Benoff et al. (2003b)New York15 semen donors in an artificialinsemination program. None wereoccupationally exposed to Pb.Seminal plasma Pb:Range <10 to >150 μg/dLCorrelation coefficient for seminal plasma Pband artificial fecundity rate is!0.641.Cullen et al. (1984)U.S.Seven men with symptomatic occupationalPb intoxication.Maximum whole blood Pb levels:66-139 μg/dLAlthough serum testosterone concentration wasnormal in six patients, five had defects inspermatogenesis, including two witholigospermia and two withazoospermia. Repeatexaminations after chelation therapy showedonly partial improvement.Heavy occupational exposure to Pb may beassociated with diffuse disturbances of endocrineand reproductive functions in men that are notrapidly reversible with standard treatment.

# AX6-175Table AX6-6.2 (cont’d). Lead Exposure and Male Reproduction: Semen QualityReference andStudy LocationStudy Description Pb Measurement Findings, InterpretationCanadaAlexander et al.(1996a)British Columbia119 workers employed at a Pb smelter. Current blood Pb:Mean 22.4 μg/dL (range 5-58)Sperm concentration and total sperm count wereinversely related to current blood Pbconcentration, with the largest effects detectedamong men with blood Pb concentrations of 40μg/dL or more.Geometric meanBlood Pb (μg/dL)sperm count×106<15 186.015-24 153.025-39 137.0∃40 89.1Blood Pb levels were notconsistently associatedwith abnormal morphology and poor motility ofthe sperm.When classified by long term exposure toPb, calculated from the mean blood Pbconcentrations of the preceding 10 yrs, similartrends were observed.

# AX6-176Table AX6-6.2 (cont’d). Lead Exposure and Male Reproduction: Semen QualityReference andStudy LocationStudy Description Pb Measurement Findings, InterpretationEuropeBonde et al. (2002)UK, Belgium, ItalyEuropean study of 503 men (362 exposed toPb, 141 unexposed controls) employed inPb industry.Blood Pb:Exposed workers:Mean 31.0 μg/dL (range 4.6-64.5)Unexposed workers:Mean 4.4 μg/dLMedian sperm concentration reduced by 49% inmen with blood Pb levels >50 μg/dL.Odds ratio for sperm count#50 million/ml inmen with blood Pb levels >50 μg/dL comparedto <10 μg/dL was 4.4 (95% CI: 1.6, 11.6).Regression analyses indicated a threshold valueof 44 μg/dL below which no adverseassociations were found.Assennato et al.(1986)Italy18 battery workers (exposed group) and 18cement workers (control group).Blood Pb:Battery workers:Mean 61 μg/dL (SD 20)Cement workers:Mean 18 μg/dL (SD 5)Semen Pb:Battery workers:Mean 79 μg/dL (SD 36)Cement workers:Mean 22 μg/dL (SD 9)Sperm count and blood Pb:r2=!0.385Sperm count and sperm Pb:r2=!0.02638% lower median sperm count and threefoldgreater prevalence of oligospermia (16.7% vs.5.5%) in battery workers compared to cementworkers.Lancranjan et al.(1975)Europe150 men occupationally exposed to Pbdivided into four groups: Pb-poisonedworkmen (n = 23) and those showing amoderate (n = 42), slight (n = 35), orphysiologic absorption (n = 50).Blood Pb:Pb poisoned workers:Mean 74.5 μg/dLModerately exposed workers:Mean 52.8 μg/dLDecreased sperm counts and increasedprevalence of morphologically abnormal spermamongst workers withheavy and moderateexposure to Pb.

# AX6-177Table AX6-6.2 (cont’d). Lead Exposure and Male Reproduction: Semen QualityReference andStudy LocationStudy Description Pb Measurement Findings, InterpretationLatin AmericaHernandez-Ochoaet al. (2005)Region Lagunera,Mexico68 environmentally-exposed men residingin Torreón, Gómez Palacio, and Lerdo forat least 3 yrs.Blood Pb:Geometric mean 9.3 μg/dL (range 2-24)Seminal fluid Pb:Geometric mean 2.02 μg/L (range 1.14-12.4)Pb in spermatozoa:Geometric mean 0.047 ng/106cells (range 0.032-0.245)Decreased sperm concentration, motility, normalmorphology and viability correlated with Pb inspermatozoa. Reduced semen volume associatedwith seminal fluid Pb.Multiple linear regression indicated thatpercentages of progressive motility andmorphology were the most sensitive parametersto Pb toxicity, which showed the highestpercentages of abnormality among the semenquality parametersevaluated.No associations were found with blood Pb.Lerda (1992)Argentina38 male workers exposed to Pb in a batteryfactory and 30 controls.Blood Pb:A (n = 12): mean 86.6 μg/dL (SD 0.6)B (n = 11): mean 65.9 μg/dL (SD 1.6)C (n = 15): mean 48.6 μg/dL (SD 4.2)Controls (n = 30): mean 23.5 μg/dL (SD 1.4)Decreased sperm count, decreased percentmotility, and increased percent with abnormalmorphology observed in all three exposuregroups compared to control group.AsiaChowdhury et al.(1986)IndiaTen men occupationally exposed to Pb in aprinting press.Blood Pb:Exposed group:Mean 42.5 μg/dLUnexposed group:Mean 14.8 μg/dLDecrease in sperm count, percent motility andincrease in number of sperm with abnormalmorphology observed in these semen samples.

# AX6-178Table AX6-6.3. Lead Exposure and MaleReproduction: Time to PregnancyReference andStudy LocationStudy Description Pb Measurement Findings, InterpretationEuropeJoffe et al. (2003)Belgium, England,Finland, ItalyAsclepios Project, large Europeancollaborative cross-sectional study.1,108 men (638 occupationally exposed toPb at the time of pregnancy) who havefathered a child.Blood Pb:Belgium: mean 31.7 μg/dLEngland: mean 37.2 μg/dLFinland: mean 29.3 μg/dLItaly: mean 29.2 μg/dLFecundity densityBlood Pb (μg/dL)ratios (95% CI)control 1.00<20 1.12 (0.84, 1.49)20-29 0.96 (0.77, 1.19)30-39 0.88 (0.70, 1.10)∃40 0.93 (0.76, 1.15)Results indicate thatno association was foundbetween blood Pb and delayed time topregnancy. Similar results were found whenduration of exposure or cumulative exposure wasused as the exposure metric.Apostoli et al. (2000)ItalyItalian men included in the Asclepiosproject. 251 exposed men and 45unexposed men with at least one completedpregnancy.Blood Pb distribution among exposed men:PercentageBlood Pb (μg/dL)of population0-19 14%20-29 40%30-39 32%∃40 14%Time to pregnancy shorter in couples in whichmale partner exposed compared to unexposed.Among the exposed men, a longer time topregnancy observed with blood Pb levels∃40 μg/dL, though not statistically significant.

# AX6-179Table AX6-6.3 (cont’d). Lead Exposure and Male Reproduction: Time to PregnancyReference andStudy LocationStudy Description Pb Measurement Findings, InterpretationEurope(cont’d)Sallmθn et al.(2000a)Finland502 occupationally exposed malesmonitored by the Finnish Institute ofOccupational Health.Blood Pb distribution (available close to time ofconception in 62% of men;in 38% estimated basedon blood Pb levels obtainedat other times or basedon job histories):PercentageBlood Pb (μg/dL)of population<10 35%10-20 40%21-30 16%31-39 4%∃40 5%Results suggest that paternal exposure to Pb maybe associated with increased time to pregnancy.Fecundity densityBlood Pb (μg/dL)ratios (95% CI)<10 1.0010-20 0.92 (0.73, 1.16)21-30 0.89 (0.66, 1.20)31-39 0.58 (0.33, 0.96)∃40 0.83 (0.50, 1.32)AsiaShiau, et al. (2004)Taiwan280 pregnancies in 133 couples in whichmale partner employed in battery plant.127 conceived during exposure; remainderconceived prior to exposure.Blood Pb:Annual means from 1987 to 1999 ranged from 32to 41 μg/dL.Fecundity densityBlood Pb (μg/dL)ratios (95% CI)unexposed 1.00<20 0.91 (0.61, 1.35)20-29 0.71 (0.46, 1.09)30-39 0.50 (0.34, 0.74)∃40 0.38 (0.26, 0.56)Using blood Pb as a continuous variable andrestricting the analysis to blood Pb levelsbetween 10 and 40 μg/dL, time to pregnancyincreased by 0.15 mos for each 1 μg/dL increasein blood Pb level.

# AX6-180Table AX6-6.4. Lead Exposure and MaleReproduction: Reproductive HistoryReference andStudy LocationStudy Description Pb Measurement Findings, InterpretationUnited StatesLin et al. (1996)New York4,256 male workers reported to the NewYork State Heavy Metals Registry(exposed) and 5,148 male bus drivers fromthe New York State Department of MotorVehicles file (control), frequency-matchedfor age and residence. Fertility during theperiod of 1981 to 1992. Records linked tobirth certificates from the New York StateOffice of Vital Statistics.Blood Pb in Pb-exposed men:Mean 37.2 μg/dL (SD 11.1)Standardized fertility ratio of Pb-exposed men incomparison with non-exposed men was 0.88(95% CI: 0.81, 0.95).Exposed group had fewer births than expected.Among those employed in Pb industry over5 yrs, a relative risk of 0.38 (95% CI: 0.23,0.61) was observed after adjusting for age, race,education, and residence.EuropeGennart et al. (1992)Belgium74 men occupationally exposed to Pb formore than 1 yr and 138 men in referencegroup with no occupational exposure.Blood Pb in Pb-exposed men:Mean 40.3 μg/dLDuration of Pb exposure:Mean 10.7 yrsCompared to reference group, odds of at leastone live birth reduced in exposed group duringthe period of Pb exposure (odds ratio of 0.65[95% CI: 0.43, 0.98]).Fertility decreased with increasing exposure(although number of men at higher exposurelevels small).Bonde and Kolstad(1997)Denmark1,349 male employees ages 20-49 yrs fromthree battery plants and control group of9,656 men not employed in Pb industry.Cohorts identified by records in a nationalpension fund. Information on birthsobtained from Danish Population Register.Blood Pb in subset of battery worker cohort (4,639blood samples from 400 workers):Mean 35.9 μg/dL (SD 13.0)No associations found between exposuremeasure and birth rate.Relative risk comparing person yrs at risk fromPb exposure with yrs at risk in reference groupwas 0.88 (95% CI: 0.81, 0.95).

# AX6-181Table AX6-6.4 (cont’d). Lead Exposure and Male Reproduction: Reproductive HistoryReference andStudy LocationStudy Description Pb Measurement Findings, InterpretationEurope(cont’d)Sallmθn et al.(2000b)FinlandOccupationally exposed males monitoredby the Finnish Institute of OccupationalHealth. 2,111 individuals with probableexposure (a blood Pb level∃10 μg/dLwithin a 5-yr time period including acalendar yr preceding the yr of marriageand 4 consecutive yrs) and 681 controls(with mean blood Pb levels <10 μg/dL).Blood Pb distribution among individuals probablyexposed:PercentageBlood Pb (μg/dL)of population10-20 51%21-30 30%31-40 11%41-50 5%∃51 3%Risk ratios among men in the probably exposedgroup:Blood Pb (μg/dL)Infertility ratios (95% CI)controls 1.0010-20 1.27 (1.08, 1.51)21-30 1.35 (1.12, 1.63)31-40 1.37 (1.08, 1.72)41-50 1.50 (1.08, 2.02)∃51 1.90 (1.30, 2.59)Results suggest that paternal exposure to Pbincreases the risk of infertility at lowoccupational exposure levels.

# AX6-182 

# ANNEX TABLES AX6-7

# AX6-183Table AX6-7.1. Recent Studies of Lead Exposure and GenotoxicityReference, StudyLocation, andPeriod Study Description Pb MeasurementFindings and InterpretationEuropeFracasso et al. (2002)ItalyCase-control design.37 workers employed at a battery plant.29 student and office worker volunteerswith no known occupational exposure togenotoxins.Peripheral lymphocytes isolated fromwhole blood.Reactive Oxygen Species (ROS)production, cellular GSH level, PKCisoforms, and DNA breaks (via comet)assayed.ANOVA and logistic regression used tocompare workers vs. healthy volunteers.Adjusted for age, alcohol use, andsmoking.Battery plant workers. Blood Pbcategories used for somecomparisons, with <25, 25-35, and>35 μg/100mL as cutpoints.Mean blood Pb 39.6 μg/100mL forworkers, 4.4 μg/100mL forvolunteers.OR (95% CI)Workers vs. Volunteers:ROS: 1.43 (0.79, 2.60)DNA breaks (tail moment):1.07 (1.02, 1.12)GSH: 0.64 (0.49, 0.82)PKCαreduced in workers, atypical PKC unchanged vs.volunteers (no statistics provided).Means (SE) via blood Pb category for ROS and GSH:<25 μg/100 mL 4.9 (0.4) and 12.8 (0.8)25-35 μg/100 mL 5.4 (0.7) and 7.7 (1.7)>35 μg/100 mL 5.4 (0.5) and 9.2 (1.2)Major analyses controlled for age,smoking, and alcohol intake.Analyses by blood Pb category not controlled for age, smoking,or alcohol intake but these factors said not to influence endpointand/or results “significantly.” No control for potentialcoexposures.

# AX6-184Table AX6-7.1 (cont’d). Recent Studies of Lead Exposure and GenotoxicityReference, StudyLocation, andPeriod Study Description Pb MeasurementFindings and InterpretationEuropePalus et al. (2003)PolandCross-sectional design.Battery plant workers: 34 acid battery,22 alkaline battery, and 52 plantpersonnel from departments with noknown exposure to Pb or cadmium.Lymphocytes isolated from whole blood.SCE, MN, DNA damage (via comet)assayed.Means compared via ANOVA.Workers considered Pb-exposed iffrom acid battery department,cadmium-exposed if from alkaline,unexposed if from other department.Mean blood Pb 504 μg/L forPb-exposed workers, 57 μg/L forcadmium-exposed, and 56 μg/L forother workers.Mean (SD)Pb exposed workers (all combined):SCEs 7.48 (0.88)MN 18.63 (5.01)NDI 1.89 (no SD given)Cadmium exposed workers (all combined):SCEs 6.95 (0.79)MN 15.86 (4.92)NDI 1.96 (no SD given)Other workers (all combined):SCEs 6.28 (1.04)MN 6.55 (3.88)NDI 1.86 (no SD given)Elevation of SCEs and MN vs. controls at p < 0.05 andp < 0.01, respectively.Both SCEs and MN elevated among Pb-exposed workers as wellas cadmium-exposed workers compared to controls. Differencesgreatest for Pb-exposed workers.Higher SCE and MN also occurred among Pb-exposed workersafter stratificationby smoking status.No direct control for potential coexposures, but mean bloodcadmium no higher in Pb-exposed than in other worker group.

# AX6-185Table AX6-7.1 (cont’d). Recent Studies of Lead Exposure and GenotoxicityReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings and InterpretationEurope(cont’d)Van Larebeke et al.(2004)BelgiumCross-sectional design.99 female nonsmokers, ages 50-65,drawn from rural and industrial areas.Peripheral lymphocytes isolated fromblood. HPRT variant frequencydetermined.Pb concentration measured in blood(serum).Women also classified as above vs.below median for blood Pb.HPRT variant frequencyAbove median serum Pb: 9.45Η10-6Below median serum Pb: 5.21Η10-6P-value for difference = 0.08 adjusted for age, education,smoking, BMI, and serum selenium. (Significant inverseassociation noted between variant frequency and serumselenium.) Uncontrolled forpotential exposure to othergenotoxins.Latin AmericaMinozzo et al. (2004)BrazilCross-sectional design.26 workers employed at a batteryrecyclery for 0.5 to 30 yrs.29 healthy volunteers of similar agerange and SES.Peripheral lymphocytes isolated fromwhole blood.Fixed blood slides stained with Giemsavisually evaluated to determinemicronuclear frequency (MN) andcellualr proliferation as nucleardivision index (NDI).ANOVA and logistic regression usedto compare workers vs. healthyvolunteers. Adjusted for age, alcoholuse, and smoking.Battery recyclery workers wereconsidered exposed.Blood Pb also determined.Mean blood Pb 35.4 μg/dL forworkers, 2.0 μg/dL for volunteers.Means (SD) for workers and volunteersMN: 3.85 (2.36) and 1.45 (1.43)NDI: 1.77 (0.22) and 1.89 (0.18)Kendal correlation coefficient:All workers{assuming recyclery workers only, not totalpopulation, but no population number given in table.}Blood PbΗMN: 0.061 (p = 0.33)Blood PbΗNDI: 0.385 (p = 0.003)Not controlled for age or SES, although worker and volunteerpopulations said to be of similarage and SES. Uncontrolled forpotential coexposures. Correlations appear uncontrolled forsmoking, age, or other factors. Differences in MN and NDIminor for smokers vs. nonsmoker, however. Diet “type”“similar” for workers and controls, although no definition ofsimilarity provided.

# AX6-186Table AX6-7.2. Key Occupational Studies of Lead Exposure and CancerReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings and InterpretationUnited StatesSteenland et al. (1992)(follow-up of Selevanet al. (1985)U.S.1940-1988Cohort design.1,990 male workers employed forat least 1 yr in a Pb-exposeddepartment at aU.S. Pb smelterin Idaho during 1940-1965.Mortality traced through 1988 todetermine cause of death.SMR computed for workers vs.national rates for age-comparablecounterparts.Exposure categorizations based onairborne Pb measurements from1975 survey. High-Pb-exposuresubgroup consisted of 1,436 workersfrom departments with an avg of least0.2 mg/m3airborne Pb or≥50% ofjobs showing 0.40 mg/m3or greater.Mean blood Pb 56 μg/dL in 1976.SMR (95% CI); number of deathsTotal cohort:Nonsignificantly elevated RRs: kidney, bladder, stomach, and lungcancer.High-Pb-exposure subgroup:Kidney 2.39 (1.03, 4.71); 8Bladder 1.33 (0.48, 2.90); 6Stomach 1.28 (0.61, 2.34); 10Lung 1.11 (0.82, 1.47); 49No control for smoking or exposure to other metals.Wong and Harris(2000)(follow-up of Cooperet al. (1985)U.S.1947-1995Cohort design.Pb battery plant (4,518) and smelter(2,300) workers.Worker mortality was followed upthrough 1995.Cause of death was identified fromdeath certificates.Mortality was compared with U.S.national age-, calendar-yr-, and genderspecific rates to compute the SMR.(See additional entry for nested studyof stomach cancer.)Workers were evaluated as a whole,and also as separate battery plant andsmelter worker populations.Job histories were also used tostratify workers by cumulative yrs ofemployment (1-9,10-19, 20+), dateof hire (pre-1946 vs. 1946 on), andlag between exposure and cancer(<20, 20-34, >34 yrs). Mean bloodPb 80 μg/dL during 1947-72 amongsmelter workers, 63 μg/dL amongbattery workers.SMR (95% CI)Battery plant workers:All cancer 1.05 (0.97, 1.13)All respiratory 1.13 (0.98, 1.29)Stomach 1.53 (1.12, 2.05)Lung, trachea, bronchus 1.14 ( 0.99, 1.30)Thyroid, Hodgkin’s: nonsignificantBladder 0.49 (0.23, 0.90)Smelter workers:Digestive, respiratory, thyroid: nonsignificantLung 1.22 (1.00, 1.47)Battery plant and smelter workers combined:All cancer 1.04 (0.97, 1.11)All respiratory 1.15 (1.03, 1.28)Stomach 1.47 (1.13, 1.90)Lung, trachea, bronchus 1.16 ( 1.04, 1.30)Thyroid/endocrine 3.08 (1.33, 6.07)Lung and stomach risks lower pre-1946 hires; higher for workersemployed 10-19 yrs than <10, but lower for >19 yrs; SMRs peakedwith 20- to 34-yr latency forlung, but <20 yrs for stomach.No control for smoking or exposure to other agents. No assessmentof employment history after 1981.

# AX6-187Table AX6-7.2 (cont’d). Key OccupationalStudies of Lead Exposure and CancerReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings and InterpretationUnited States(cont’d)Wong and Harris(2000)U.S.1947-1995.(Nested in Wong andHarris 200 cohort.)Case-control design.Cases: the 30 stomach cancer casesoccurring in a Philadelphia Pb batteryplant.Controls: 120 age-matched cohortmembers.Mean exposure was compared forcases vs. controls. Odds of exposurewere also computed for increasingquartiles of cumulative exposure.Job titles were used to classify Pbexposure as low, intermediate, orhigh; total mos of any exposure, ofintermediate or high exposure only,and of cumulative exposure, withmos weighted by 1, 2, or 3 if spent inlow-, intermediate-, or high-exposurejob.Mean mos of employment, of intermediate or high exposure, or ofweighted exposure to Pb wereall nonsignificantly lower amongcases.OR for cumulative weighted exposure in the 10 yrs prior to death:1st quartile 1.002nd quartile 0.623rd quartile 0.824th quartile 0.61p for trend = 0.47; ORs showed no positive association withany index of exposure.Analyses appear uncontrolled for smoking, other occupationalexposures, or other risk factors.EuropeFanning (1988)(Cases overlap thoseoccurring inDingwall-Fordyce andLane, 1963; andMalcolm and Barnett,1982).U.K.1926-1985Proportional mortality/cohort design.Subjects:2,073 deceased malesidentified through pension records ofPb battery and other factory workers inthe U.K.Workers dying from a specific cancerwere compared with workers dyingfrom all other causesWorkers were classified as High ormoderate Pb exposure vs. little or noexposure based on job titles.OR (95% CI); number of deathsLung cancer: 0.93 (0.8, 1.1); 76Stomach cancer: 1.34; 31No associations for other cancer types; elevations in stomach andtotal digestive cancers limited to the period before 1966.

# AX6-188Table AX6-7.2 (cont’d). Key OccupationalStudies of Lead Exposure and CancerReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings and InterpretationEurope(cont’d)Anttila et al. (1995)Finland1973-1988Cohort plus case-referent design.20,700 workers with at least one bloodPb measurement between 1973 and1983.Workers were linked to the FinnishCancer Registry for follow-up through1988. For deceased workers, cause ofdeath was identified from deathcertificate.Mortality and incidence were comparedwith gender-, 5-yr age, and 4-yrcalendar-yr matched national rates.Exposure was categorized accordingto the highest peak blood levelmeasured:Low: 0-0.9 μmol/L(0-18.6 μg/dL)Moderate: 1-1.9 μmol/L(20.7-39.4 μg/dL)High: 2-7.8 μmol/L(41.4-161.6 μg/dL)Mean blood Pb 26 μg/dL.Total cohort:No elevation in total or site-specific cancer mortality.Moderately exposed:Total respiratory and lung cancer:SIR = 1.4 (95% CI: 1.0, 1.9) for bothTotal digestive, stomach, bladder, and nervous system:nonsignificant elevations.Highly exposed:No increase in risks.All cancer:RR = 1.4 (95% CI: 1.1, 1.8)Lung or tracheal:RR = 2.0 (95% CI: 1.2, 3.2)No increase in high-exposure group.No RRs reported for other cancers.Case-referent substudies:Lung cancer ORs increased with increasing cumulativeexposure to Pb.Highly exposed: squamous-cell lung cancer OR of 4.1(95% CI: 1.1, 15) after adjustment for smoking.Short follow-up period limits statistical power, offset to alarge degree by the substantialsample size. No control forexposure to other potential carcinogens.

# AX6-189Table AX6-7.2 (cont’d). Key Occupational Studies of Lead Exposure and CancerReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings and InterpretationEurope(cont’d)Anttila et al. (1996)Finland1973-1988(Nested analysis basedon Antilla et al., 1995cohort)Case-control design.(See Anttila et al., 1995 for basicinformation on thesource population.)Cases: 26 Finnish men with CNScancer.Controls:200 Finnish men withoutCNS cancer.Nested case-control analysis.Peak blood Pb levels used tocategorize exposure as 0.1-0.7,0.8-1.3, and 1.4-4.3 μg/L.Cumulative exposure estimated byusing mean annual blood Pb level tocategorize exposure as0, 1-6, 7-14,or 15-49 μg/L.Interviews were used to obtainoccupational history and other risk-factor data from patients or nextof kin.Number of cases or deathsCNS cancer incidence(26 cases):Rose with increasing peak lifetimeblood Pb measurements; not significant.Glioma mortality(16 deaths):Rose consistently and significantlywith peak and mean blood Pb level, duration of exposure, andcumulative exposure.Mortality by cumulative exposure,controlled for cadmium, gasoline,and yr monitoring began:Low (13 subjects) 2.0 (2)Medium (14 subjects) 6.2 (2)High (16 subjects) 12.0 (5)One death among 26 subjects with no exposure: test for trendsignificant at p= 0.02.Controlled for smoking as well as exposure to cadmium and gasoline.Complete follow-up with minimal disease misclassification.Gerhardsson et al.(1995)Sweden1969-1989Cohort design.684 male Swedish secondary Pb smelterworkers with Pb exposure.Cancer incidence among workers wastraced through 1989.Incidence was compared with countyrates.Blood Pb level: any worker with adetectable blood Pb level wasclassified as exposed.SIR (95% CI); number of casesAll malignancies:1.27 (0.91, 1.74); 40Respiratory:1.32 (0.49, 2.88); 6All gastrointestinal:Cohort 1.84 (0.92, 3.29); 11Highest quartile 2.34 (1.07, 4.45); 9Stomach:1.88 (0.39, 5.50); 3Colon:1.46 (0.30, 4.28); 3SIRs for all other sites except brain were nonsignificantly elevated;too few cases.No control for smoking. Small numbers, so meaningful doseresponse analyses not possible for most cancer sites.

# AX6-190Table AX6-7.2 (cont’d). Key OccupationalStudies of Lead Exposure and CancerReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings and InterpretationEurope(cont’d)Lundström et al.(1997)(follow-up ofGerhardsson et al.(1986)(see also subcohortanalyses of Englystet al., 2001).Sweden1928-1987Cohort design.3,979 copper and Pb smelter workers.Standardized mortality and incidenceratios were computed for workerscompared with age-, yr-, gender-, andcounty-specific rates for the generalpopulation.For some analyses, the entire cohortwas treated as exposed. For others,job histories were used to single out1,992 workers belonging todepartments thought to be exposed to“Pb only.” Mean blood Pbmonitoring test results across timewere used to single out a “highlyexposed” group of 1,026 workerswith blood Pb levels≥10 μmol/L[≥207 μg/dL].Mean blood Pb 60 μg/dL in 1959.SMR (95% CI); number of deathsLung:Total cohort 2.8 (2.0, 3.8); 39Highly exposed 2.8 (1.8, 4.5); 19SIR (95% CI); number of casesLung with 15-yr lag:Total cohort 2.9 (2.1, 4.0); 42Highly exposed 3.4 (2.2, 5.2); 23Pb-only 3.1 (1.7, 5.2); 14Pb-only highly exposed 5.1 (2.0, 10.5); 7Other highly exposed (total cohort), with 15-yr lag:Brain 1.6 (0.4, 4.2); 4Renal pelvis, ureter, bladder 1.8 (0.8, 3.4); 9Kidney 0.9 (0.2, 2.5); 3All cancer 1.1 (0.9, 1.4); 83No control for smoking.Englyst et al. (2001)(follow-up and subanalysis of Lundströmet al., 1997).Sweden1928-1987Nested cohort analysis.Limited to 1,093 workers in thesmelter’s Pb department, followedthrough 1997.Incidence was compared with countyrates; age-specific SIRs with 15-yr lag.Workers were divided intoSubcohorts I and II for ever andnever worked in areas generallyassociated with exposure to arsenicor other known carcinogens (701 and383 workers, respectively).Detailed individual assessment ofarsenic exposure was made for alllung-cancer cases.SIR (95% CI); number of casesSubcohort I (coexposed):Lung 2.4 (1.2, 4.5); 10Subcohort II (not coexposed):Lung 3.6 (1.2, 8.3); 5Subjects with lung cancer found to have history of “considerable”exposure to arsenic: 9/10among Subcohort I, 4/5 amongSubcohort II.No control for smoking.

# AX6-191Table AX6-7.2 (cont’d). Key OccupationalStudies of Lead Exposure and CancerReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings and InterpretationEurope(cont’d)Carta et al. (2003)Sardinia1972-2001Cohort design.918 Pb smelter workers.Mortality traced from 1972 through2001.Standardized mortality ratios computed.Smelter workers considered exposed.Job histories also used to categorizedegree of exposure based onenvironmental and blood Pbmeasurements for specificdepartments and tasks during1985-2001.SMR; number of casesSmelter workers as a wholeAll cancer 1.01; 108Gastric cancer 1.22; 4Lymphoma/leukemia 1.82; 6Lung cancer 1.21; 18Highly exposed workersLung cancer 1.96 (95% CI: 1.02, 3.68) for highest exposuregroup, with statistically significant upward trend.Analyses for worker population as a whole supported bypresence of dose-response pattern for lung cancer based onestimated exposure. Modest population size, inability to assessdose-response for cancers of interest other than lung. No controlfor smoking or other occupational exposures.

# AX6-192Table AX6-7.3. Key Studies of Lead Exposureand Cancer in the General PopulationReference, StudyLocation, and Period Study DescriptionPb Measurement Findings and InterpretationUnited StatesJemal et al. (2002)(same cohort as inLustberg andSilbergeld, 2002except for inclusioncriteria)U.S.1976-1992.Cohort design.3,592 white participants from the1976-1980 NHANES II survey whohad blood Pb measured at entry.Mortality was followed through 1992via NDI and SSADMF.RRs were calculated for the variousexposure groups compared to surveyparticipants with the lowest exposure,adjusted for age and smoking.Blood Pb (μg/dL) was measuredby atomic absorption and used toclassify subjects into exposurequartiles or groups above vs.below median exposure.Median blood Pb 12 μg/dL.RR (95% CI); number of deathsLung (above vs. below median):Total cohort 1.5 (0.7, 2.9); 71Male 1.2 (0.6, 2.5); 52Female 2.5 (0.7, 8.4); 19Stomach (above vs. below median):Total cohort 2.4 (0.3, 19.1); 5Male 3.1 (0.3, 37.4); 4Female no deaths in referent groupAll cancer: total cohort by quartile(age-adjusted) 1.0, 1.2, 1.3, 1.5(p = 0.16 for trend).Smoking was controlled for. Pb levelsoccurring in the general populationwere examined, not just those in workers with high occupational exposurepotential. Exposure to other carcinogenswere not examined. Potential forresidual confounding by degree andduration of smoking exists (onlycontrolled for never, former, current<1, current 1+ pack/day). Limitedcase numbers yield low statistical power for stomach or other cancers.

# AX6-193Table AX6-7.3 (cont’d). Key Studies of Lead Exposure and Cancer in the General PopulationReference, StudyLocation, and Period Study DescriptionPb Measurement Findings and InterpretationUnited StatesLustberg andSilbergeld (2002)(same cohort as Jemalet al., 2002 except forinclusion criteria)U.S.1976-1992.Cohort design.4,190 U.S. participants from the 1976-1980 NHANES II health and nutritionsurvey who had blood Pb measured atentry and whose levels fell below30 μg/dL.Mortality was followed through 1992via NDI and SSADMF.RRs were calculated for the variousexposure groups compared to surveyparticipants with the lowest exposure,adjusted for age, smoking and otherfactors.Blood Pb (μg/dL) measured byatomic absorption was used toclassify subjects into exposuregroups:Low: <10Medium: 10-19High: 20-19Mean blood Pb 14 μg/dL.RR (95% CI)All cancer, vs. low exposure:Medium 1.5 (0.9, 2.5)High 1.7 (1.0, 2.8)Lung, vs. low exposure:Medium 1.7 (0.6, 4.8)High 2.2 (0.8, 6.1)Non-lung, vs. low exposure:Medium 1.5 (0.8, 2.8)High 1.5 (0.8, 2.8).Significant upward trends noted forall-cause and for cardiovascularmortality with increasing Pb category.Smoking was controlled for in the analysis. Pb levels occurring in thegeneral population wereexamined, with individuals showing levelsconsistent with intense occupational exposure excluded, thus allowingexploration of potential effects outside of groups experiencing intenseoccupational exposure. Exposure to other carcinogens were not examined.Potential for residual confounding by degree and duration of smokingexists (only controlled fornever, former, current <1, current 1+ pack/day).Limited case numbers yield low statistical power for stomach or othercancers.

# AX6-194Table AX6-7.4. Other Studies ofLead Exposure and CancerReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings and InterpretationUnited StatesMallin et al. (1989)Illinois1979-1984Case-control design.Cases: random sample of 10,013 deathsfrom 7 specific cancers, identified fromdeath certificates for Illinois malesbetween 1979 and 1984.Controls: 3,198 randomly selecteddeaths from other causes.Odds of exposure computed for glassworkers vs. other occupations.Exposure was based onoccupations abstracted fromdeath certificates.No specific measure of Pbexposure; glass workers can beconsidered potentially exposed.Brain cancer, white male glass workers:OR = 3.0, p < 0.05No significant associationsfor other cancer sites.No control for smoking or other riskfactors. Poor specificity for Pbexposure.Cocco et al. (1998a)U.S.1984-1992Case-control design.Cases: all 27,060 brain cancer deathsoccurring among persons aged 35 orolder during 1984-1992, from U.S.24-state death certificate registry.Controls: 4 gender-, race-, age-, andregion-matched controls per caseselected from deaths due tononmalignant causes.Subjects were subdivided into 4 groupsby gender and race (white or AfricanAmerican) for all analyses.A job-exposure matrix wasapplied to death certificate-listedoccupations to categorizepersons as having low, medium,or high probability and intensityof exposure.Risk of brain cancer mortality increased consistently with intensity ofexposure among African-American males, but not other race-gendergroups.Probability of exposure alone was not consistently associated withrisk.In the high-probability group, riskincreased with exposure intensityfor all groups except African-American women (only 1 death in thehigh-probability group).Exposure estimate was based solely on occupation listed on deathcertificate, hence there was substantial opportunity formisclassification.

# AX6-195Table AX6-7.4 (cont’d). Other Studies of Lead Exposure and CancerReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings and InterpretationUnited States(cont’d)Cocco et al. (1998b)U.S.1984-1992Case-control design.Cases: all 28,416 CNS cancer deathsoccurring among persons aged 35 orolder during 1984-1992, from U.S.4-state death certificate registry.Controls: 4 gender-, race-, age-, andregion-matched controls per caseselected from deaths due tononmalignant causes.Subjects were subdivided into 4 groupsby gender and race (white or African-American) for all analyses.Death certificate listed industryand occupation was used tocategorize decedents. Noestimates of Pb exposurespecifically.OR (95% CI)All occupations or industries withORs above 1.0 and p < 0.05 in atleast one race-gender group were reportedNewspaper printing and publishing industry:White male 1.4 (1.1, 1.8)Black male 3.1 (0.9, 10.9)Typesetting and compositing:White male 2.0 (1.1, 3.8)White female 1.3 (0.4, 3.8)Black female 4.2 (0.6, 30.7)No deaths among black males.Only two Pb exposure associatedoccupations or industries showed astatistically significant elevation of mortality. No specific measuresof Pb exposure. Occupation basedsolely on death certificate, hencethere was substantial opportunity for misclassification.

# AX6-196Table AX6-7.4 (cont’d). Other Studies of Lead Exposure and CancerReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings and InterpretationUnited States(cont’d)Cocco et al. (1999)U.S.1984-1996Case-control design.Cases: all 41,957 stomach cancer deathsoccurring among persons aged 35 orolder during 1984-1996, from U.S.24-state death certificate registry.Controls: 2 gender-, race-, age-, andregion-matched controls per caseselected from deaths due tononmalignant causes.Subjects were subdivided into 4 groupsby gender and race (white or African-American) for all analyses.A job-exposure matrix wasapplied to death certificate-listed occupations to categorizepersons as having low, medium,or high probability and intensityof exposure.OR (95% CI)Adjusted for age, ethnicity, marital status, urban residence, andsocioeconomic status.Elevated ORs:White female, high probability ofexposure 1.53 (1.10, 2.12)Black male, high probability ofexposure 1.15 (1.01, 1.32)Black female, high probability ofexposure 1.76 (0.74, 4.16)Highly exposed group included 1,503 white and 453 black men and65 white and 10 black women; no pattern of increase across exposurelevels.Intensity of exposure showed noassociation with stomach cancerexcept for black women:Low 1.82 (1.04, 3.18)Moderate 1.39High 1.25No control for other occupational exposures. Exposure estimatebased on occupation listed on deathcertificate and hence subject tomisclassification due tomissing longest-held job.

# AX6-197Table AX6-7.4 (cont’d). Other Studies of Lead Exposure and CancerReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings and InterpretationCanadaRisch et al. (1988)Canada1979-1982Case-control design.Cases:826 Canadian men withhistologically confirmed bladder cancerduring 1979-1982.Controls:792 controls fromCanadian population, matched on age,gender, and area.Odds of exposure toPb for cases vs.controls were computed, adjusted forsmoking and other risk factors.Subjects were interviewedregarding length ofoccupational exposure to Pbcompounds, as well as 17 othersubstances.OR (95% CI)61 men ever exposed to Pb (smoking-adjusted):2.0 (1.2, 3.5)Trend per 10 yrs duration of exposure:1.45 (1.09, 2.02)No other substances showed significant associations with bladdercancer.Controlled for smoking, maritalstatus, socioeconomic status,education, ethnicity, and urban vs. rural residence.No control for other occupationalexposures. Low control interviewrate (53%), which could resultin biased control sample.Siemiatycki et al.(1991)CanadaCase-control design.Cases:3,730 various histologicallyconfirmed cancers.Controls:specific cancer types werecompared with other cancers as a controlgroup, excluding lung cancer.Separate subgroup analysis wasrestricted to French Canadians.Occupational exposure to293 substances, including Pb,was estimated from interviews.Exposure was classified as“any”; a subgroup with“substantial” exposure also wasidentified.OR (90% CI); number of casesAny exposure to Pb:Lung 1.1 (0.9, 1.4); 326(French Canadians only)Stomach 1.2 (1.0, 1.6); 126Bladder 1.3 (1.0, 1.6); 155(French Canadians only)Kidney 1.2 (1.0, 1.6); 88ORs rose in the “substantial”exposure subgroup for stomach andlung, but not for bladder or kidney cancer.Controlled for smoking but not for other occupational exposures.

# AX6-198Table AX6-7.4 (cont’d). Other Studies of Lead Exposure and CancerReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings and InterpretationEuropeSankila et al. (1990)Finland1941-1977Cohort design.1,803 male and 1,946 female glassworkers employed for at least 3 mos atone of 2 Finnish glass factories in 1953-1971 or 1941-1977.Cancer incidence was compared withage-, gender-, and calendar-yr-specificnational rates.Stomach, lung, and skin cancer rates alsowere compared separately for 201 maleand 34 female glassblowers and non-glassblowers.No specific Pb exposure indiceswere computed. Analyses didexamine glass workers as awhole and then glassblowersspecifically, which comprisedthe group at highest risk for Pbexposure.SIR (95% CI); number of casesLung cancer, all glass workers:Male 1.3 (1.0, 1.7); 62Female 1.1 (0.5, 2.3); 7Lung cancer risk showed no specificity for glassblowers.Skin cancer, males and females combined:All workers 1.5 (0.8, 2.7); 11 (little difference between genders)Glassblowers 6.2 (1.3, 18.3); 3Stomach cancer, males and females combined:Glassblowers 2.3 (0.9, 5.0); 6No increase in other glass workersNo increase in cancers of other sites. No control for smokingor occupational coexposures.Kauppinen et al.(1992)Finland1976-1981Case-control design.Cases:344 primary liver cancer deathsreported to the Finnish Cancer Registryin 1976-1978 or 1981.Controls:registry-reported stomachcancer (476) or myocardial infarction(385) deaths in the same hospitals,frequency matched by age and gender.Questionnaires regarding jobhistory and personal habits weresent to the closest availablerelative.U.K. based job-exposure matrixwas used to rate potentialexposure to 50 substances,including Pb compoundsIndustrial hygienists alsoinspected histories to identifythose with highly probableexposure and rate it as high,low, or moderate (<10 yrs highor 10+ yrs low exposure).OR (95% CI)52 workers with potential Pb exposure:0.91 (0.65, 1.29)11 womenwith potential Pb exposure:1.84 (0.83, 4.06)5 men with probable moderate exposure:2.28 (0.68, 7.67)None had high exposure and only1 had low exposure, whereas4 controls had high exposure.Female controls appeared to underreport their job history.Most controls had stomach cancer, which if caused by Pb would biasresults toward the null. Few subjects were rated as having a highprobability of exposure.

# AX6-199Table AX6-7.4 (cont’d). Other Studies of Lead Exposure and CancerReference, StudyLocation, andPeriod Study Description Pb Measurement Findings and InterpretationEurope(cont’d)Wesseling et al.(2002)Finland1971-1995Cohort design, but at ecologic level.413,877 Finnish women with occupationreported in 1970 linked to Finnish CancerRegistry to identify new cases of brain ornervous system cancer arising form1971 to 1995.Poisson regression was used to calculate SIRsfor exposed vs. unexposed groups.Reported occupation in 1970 wasused to classify women into jobtitles. Potential exposure foreach job title was estimatedusing a job matrix afterexcluding women in the highestsocial classes or in farming. Pband 23 other workplace agentsexamined. Rates for each jobtitle were calculated, and SIRsfor low and medium/highexposure calculated (avgestimated blood Pb of0.3 μmol/L served as cut pointbetween low and medium/highexposure).SIR (95% CI), unadjusted for other metalsLow exposure: 1.25 (0.68, 1.81)Medium/high exposure: 1.33 (0.90, 1.96)SIR (95% CI), adjusted for cadmium and nickel exposureLow exposure: 1.18 (0.88, 1.59)Medium/high exposure: 1.24 (0.77, 1.98)All results were adjusted for birth cohort, period of diagnosis, andjob turnover rate.Incidence, exposure to Pb, andpotential confounding factors werecalculated at the level of job title rather than at the individuallevel. Exposure and other estimates were based on data for allworkers pooled, not for women specifically. Job classificationwas based on a single yr,not lifetime job history.Pesch et al. (2000)Germany1991-1995Case-control design.Cases:935 renal-cell cancer patients in fiveGerman areas.Controls:4,298 region, age, and gendermatched controls from the surroundingpopulation.ORs were adjusted for age, center,and smoking.Job histories were used tocategorize exposure to cadmium,Pb, and other potential as low vs.medium, high, or substantial.Separate exposure estimateswere obtained from British andfrom German-derived jobexposure matrices.OR (95% CI); number of casesSubstantial Pb exposure based on British matrix:Male 1.5 (1.0, 2.3); 29Female 2.6 (1.2, 5.5); 11Substantial Pb exposure based on British matrix:Male 1.3 (0.9, 2.0); 30Female not reportedAnalyses controlled for smoking. No control for exposure toother occupational agents.

# AX6-200Table AX6-7.4 (cont’d). Other Studies of Lead Exposure and CancerReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings and InterpretationEurope(cont’d)Kandiloris et al. (1997)GreeceCase-control design.Cases:26 patients with histologicallyconfirmed laryngeal carcinoma and nohistory of Pb exposure or toxicity.Controls:53 patients with similardemographic profiles and no history ofcancer from the same hospital.Blood Pb levels and ALAD activity weremeasured.Blood Pb levels were similar, but ALAD activity wassignificantly lower in casesthan controls (Mean 50.79 U/Lvs. 59.76 U/L, p < 0.01). No control for other risk factors.Potential distortion by effects of disease on Pb and/orALAD parameters.)Cordioli et al. (1987)Italy1953-1967Cohort design.468 Italian glass workers employed forat least one yr between 1953 and 1967.Mortality among workers was trackedand cause of death was determined fordeceased workers. Standardizedmortality ratios were computed forworkers vs. national populationcounterparts.Workers producing low-quality glasscontainers were classified as Pb-exposed.SMR (95% CI); number of deathsAll cancer 1.3 (0.8, 1.8); 28Lung2.1 (1.1, 3.6); 13Laryngeal 4.5 (1.2, 11.4); 4Cocco et al. (1994a)(expansion of Cartaet al., 1994).Sardinia1931-1992Cohort design.1,741 male Sardinian Pband zinc minersfrom two mines employed at least one yrbetween 1931 and 1971.Mortality traced through 1992 todetermine cause of death.Mortality among miners was comparedwith age- and calendar-yr-specificregional rates to compute an SMR.All miners were considered to be exposedto Pb.SMR (95% CI); number of deathsAll cancer 0.94 (0.83, 1.05); 293Prostate 1.21;16Bladder 1.15;17Kidney 1.28;7Nervous system 1.17; 8Oral 0.61;8Lymphohemopoietic 0.91; 21Digestive 0.83;86Peritoneum3.67 (1.35, 7.98); 6No other p < 0.05.No control for smoking or exposure to silica, radon, orother exposures.

# AX6-201Table AX6-7.4 (cont’d). Other Studies of Lead Exposure and CancerReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings and InterpretationEurope(cont’d)Cocco et al. (1994b)Sardinia1951-1988Cohort design.526 female Sardinian Pb andzinc miners from the samemines as in Cocco et al.(1994a).Mortality traced through 1992to determine cause of death.Mortality among miners wascompared with age- andcalendar-yr-specific regionalrates to compute an SMR.All miners were considered to beexposed to Pb.SMR (95% CI)Liver 5.02 (1.62, 11.70)Lung 2.32 (0.85, 5.05)Other cancers showed nonsignificantly reduced rates.No control for smoking or exposure to silica, radon, or other exposures.Low statistical power dueto small population and paucity of cancersduring follow-up.Cocco et al. (1996)Sardinia1973-1992Cohort design.1,222 male Sardinian Pb andzinc smelter workers whoseG6PD phenotypes had beendetermined, employed anytime from 1973-1990.Mortality traced through 1992to determine cause of death.Mortality was compared withregional rates.All workers were considered to beexposed to Pb.Workers were subdivided into6PD-normal and -deficient groups.All cancer and lung cancer: mortality lower than expectedStomach cancer: mortality higher than expectedG6PD deficiency had little apparent effect on mortality: cancer and allcause mortality was slightly loweramong G6PD-deficient workers thanamong G6PD-normal workers.No control for smoking or exposure to other agents in the smelter.Healthy worker bias-evident (all-cause mortality 31 observed vs. 44expected), brief follow-up, low proportion of older ages (mean age atentry 30, avg follow-up less than 11 yrs), no cumulative exposure data.

# AX6-202Table AX6-7.4 (cont’d). Other Studies of Lead Exposure and CancerReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings and InterpretationEurope(cont’d)Cocco et al. (1997)Sardinia1931-1992Cohort design.1,388 male production and maintenanceworkers employed for at least 1 yr at aSardinian Pb and zinc smelter betweenJune of 1932 and July of 1971.Mortality was followed up through 1992.Mortality was compared with age- andcalendar-yr-specificregional rates.Since regional rates were only availablefor 1965 and later, analyses were limitedto this period.All workers were considered tobe exposed to Pb.SMRs vs. regional rates (95% CI); number of deathsLung 0.82 (0.56, 1.16); 31Stomach 0.97 (0.53, 1.62); 14All cancers 0.93 (0.78, 1.10); 132Kidney 1.75 (0.48, 4.49); 4Bladder 1.45 (0.75, 2.53); 12Brain 2.17 (0.57, 5.57); 4Kidney cancer showed a significanttrend toward increasing risk withincreasing duration of exposureNo significant trends were noted for lung or other cancersBrain cancer excess was limited to workers employed for 10 yrs orless.No control for smoking or exposure to arsenic or other smelter-related exposures. No dataon intensity of exposure.Strong association of smelter workwith pneumoconiosis and otherrespiratory disease (SMR = 4.47, 95% CI: 3.37, 5.80); since thisoutcome includes silicosis, which is thought to predispose individualsto lung cancer, some lung cancer deaths may have been missed due tomisclassification of cause of death based on death certificates.Wingren and Axelson(1987, 1993)(update of Wingrenand Axelson, 1985,same basic cohort as inWingren andEnglander (1990)Sweden1950-1982Case-control design.Source population:5,498 men aged45 or older in 11 Swedish parishes,including 887 glass workers.Cancer-specific nested case-controlanalysis:Cases:deaths due to stomach, colon,and lung cancer from 1950-1982Controls:deaths due to causes otherthan cancer or cardiovascular diseaseGlass workers were consideredexposed.Glassblowers also singled outas workers with higherexposure potential.Job history applied to jobmatrix to categorizeoccupations as low, moderate,or high Pb exposure.OR (90% CI); number of deathsAll glass workers:Lung 1.7 (1.1, 2.5); 86Stomach 1.5 (1.1, 2.0); 206Colon 1.6 (1.0, 2.5); 79Glassblowers:Lung 2.3Stomach 2.6Colon 3.1Glassblowers singled out from glass workers as a whole thus showedhigher estimated risk. ORs for high or moderate vs. low exposureshowed no consistent increase for lung or stomach cancer, however,although they did show mild upward trend for colon cancer.No control for smoking or other occupational exposures.

# AX6-203Table AX6-7.4 (cont’d). Other Studies of Lead Exposure and CancerReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings and InterpretationEurope(cont’d)Wingren andEnglander (1990)Sweden1964-1985(same population as incase-control analysesof Wingren andAxelson 1985, 1987,1993)Cohort design.625 Swedish glass workers employedfor at least 1 mo between 1964and 1985.Mortality was compared with nationalrates.Workers from areas withairborne Pb levels up to 0.110mg/m3were classified asexposed.SMR (95% CI)Pharyngeal:9.9 (1.2, 36.1)Lung:1.4 (0.5, 3.1)Colon: nonsignificantDingwall-Fordyceand Lane (1963)U.K.1925-1962Cohort design.425 male employees drawing pensionsfrom U.K. battery plants.Standardized mortality for employeesvs. national population counterparts.Battery plant workers wereassumed to be exposed, andtheir mortality compared to thatof like age and gender in theU.K. population as a whole.Urinary Pb excretion was alsoused to categorize workers byestimated exposure (none, light,or heavy): 80 lightly and 187heavily (at least 100 μg/L)exposed.SMR (95% CI); number observed deathsAll cancer: 1.2 (0.8, 1.7); 267No consistent increase in SMRsacross categories of increasing Pbexposure.Limitations: No cancer site-specific analyses. No control forpotential confounders including smoking and exposure to arsenic orother metals.Malcolm and Barnett(1982) (follow-up ofDingwall-Fordyce andLane, 1963)U.K.1925-1976Cohort design.1,898 Pb-acid battery workers.Mortality was traced for the Pb-acidbattery workers to determine cause ofdeath. The proportion of deaths due tocancer (all types and majorsubcategories) among the workerpopulation was compared to that seen incorresponding members of the generalpopulation, yielding a PMR.Job histories were reviewed toclassify workers’ Pb exposureas high, medium, or none.Proportionate mortality ratio (PMR)All cancers:1.15 (136 deaths), p > 0.05By exposure:None 1.02Medium 1.06High 1.30No significant excesses for individual cancer sites except fordigestive cancer PMR of 1.67, p< 0.01, among nonexposed workers.The difference in exposure for the high and medium exposure groupsnarrowed greatly over the follow-up,thus complicating interpretationof dose-response patterns. No control for smoking or occupationalexposure to other carcinogens.

# AX6-204Table AX6-7.4 (cont’d). Other Studies of Lead Exposure and CancerReference, StudyLocation, and Period Study DescriptionPb Measurement Findings and InterpretationEurope(cont’d)Ades and Kazantzis(1988)U.K.1943-1982Cohort design.4,393 male zinc, Pb, and cadmium smelterworkers.(Workers born after 1939 or who had workedless than one yr at the facility were excluded.)Workers followed up for mortality.Nested case-control analysis also conducted toquantitatively assessed cadmium and,secondarily, arsenic,Pb, and other metalexposures among 174 cases.Job histories were used to quantifycadmium exposure and assignordinal ranks for exposure to Pb andother metals.Standardized lung cancer mortalityratio computed for workers vs.national rates.SMR (95% CI); number of deathsCohort:Lung 1.25 (1.07, 1.44); 174Increased significantly with duration of employment.Nested case-control analyses did not implicate anydepartment or process, nor didcadmium, zinc, sulfur dioxide,or dust exposure account for the observed increase.Cumulative exposure to Pb and to arsenic both showedpositive associations with lung cancer, but the relativeimportance of these two exposures could not be determined.Cadmium exposure did not account for the elevated SMR,but analyses could not control for exposure, and were notadjusted for smoking.AsiaHu et al. (1998)China1989-1996Case-control design.Cases:218 patients with histologicallyconfirmed primary gliomas occurring during1989-1996 at 6 Chinese hospitals.Controls:436 patients withnon-neurological,nonmalignant disease, matched by age, gender,and residence from the same hospitals(excluding one cancer-only center).Patients were interviewed, and thosewith factory or farm occupationswere further interviewed to identifyexposure to Pb (or other potentiallytoxic substances).Occupational exposure to Pb:Not reported for any glioma patients, but was reported for4 controls.No control for exposure to other occupational orenvironmental agents.

# AX6-205Table AX6-7.4 (cont’d). Other Studies of Lead Exposure and CancerReference, StudyLocation, and Period Study DescriptionPb MeasurementFindings and InterpretationAsia(cont’d)Hu et al. (1999)China1989-1996Case-control design.Cases:383 patients with histologicallyconfirmed primary meningiomasoccurring during 1989-1996 at 6 Chinesehospitals.Controls:366 patients with non-neurological, nonmalignant diseasematched by age, gender, and residencefrom the same hospitals (excluding onecancer-only center).Patients were interviewed, andthose with factory or farmoccupations were furtherinterviewed to identifyexposure to Pb (or otherpotentially toxic substances).OR (95% CI); number of casesOccupational exposure to Pb:Male: 7.20 (1.00, 51.72); 6Female: 5.69 (1.39, 23.39); 10Results were adjusted for income, education, and fruit and vegetableintake, plus cigarette pack-yrs for the women. No control forexposure to additional metals orother occupational exposures.Shukla et al. (1998)India1995-1996Case-control design.Cases:38 patients with newlydiagnosed, histologically confirmed gallbladder cancer cases assembled from asurgical unit.Controls:58 patients with gall stonesdiagnosed at the same surgical unit,matched on geographic area.Mean bile Pb content was comparedbetween cases and controls.Heavy metal content wasmeasured in bile drawn fromthe gall bladder at time ofsurgery.Bile Pb content: mean (SE)Gall bladder cancer: 58.38 mg/L (1.76)Gallstones: 3.99 mg/L (0.43)Cadmium and chromium levels also were elevated in cancer patients,but less than Pb. No control for smoking or any other risk factors.

# AX6-206 

# ANNEX TABLES AX6-8

# AX6-207Table AX6-8.1. Effects of Lead on Immune Function in ChildrenReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationUnited StatesJoseph et al. (2005)SE Michigan(1994-1998)Design: prospective (1 yr following 3-yrbaseline recruitment)Subjects: children (n = 4634), age range0.4–3.0 yrOutcome measures: asthma prevalence andincidence.Analysis: multivariate proportional hazardmodel (Cox)Blood Pb (μg/dL) mean(SD, median, % >10):5.5 (4.0, 4.0, 8.6%)Covariate-adjusted hazards ratio (HR, asthma incidence <5 μg/dLcompared to∃5 or∃10 μg /dL):Caucasian:∃5 μg/dL, 1.4 (95% CI: 0.7, 2.9)∃10 μg/dL, 1.1 (95% CI: 0.2, 8.4)African American:∃5 μg/dL, 1.0 (95% CI: 0.8, 1.3)∃10 μg/dL, 0.9 (95% CI: 0.5, 1.4)HR for asthma incidence in African Americans, compared toCaucasians (<5 μg/dL):<5 μg/dL: 1.6 (95% CI: 1.4, 2.0)∃5 μg/dL: 1.4 (95% CI: 1.2, 1.6)∃10 μg/dL: 2.1 (95% CI: 1.2, 3.6)Covariates included: avg annual income, birth weight, and gender.Sarasua et al. (2000)ATSDR Multi-siteStudy: Granite City,IL, Galena, KA; Joplin,MO; Palmerton, PA1991Design: cross-sectionalSubjects: children and adults (n = 2036)Outcome measures: total lymphocyte count,lymphocyte phenotype abundance, serumIgA, IgG, and IgM.Analysis: multivariate linear regressionBlood Pb (μg/dL) mean(SD, 5th–95th %):6–35 mo: 7.0(16, 1.1–16.1)36–71 mo: 6.0(4.3, 1.6–14.1)6–15 yr: 4.0(2.8,1.1–9.2)16–75 yr: 4.3(2.9, 1.0–9.9)Significant association (p < 0.05) between increasing blood Pb andincreasing serum IgA, IgG, IgM, and B-cell abundance (%, number),and decreasing T-cell abundance (%) in 6–35 mo age category;adjusted for age, sex, and studysite. Comparison of outcome meansacross blood Pb quartiles (1st quartile as reference, [+], higher, [−]lower): [+] lymphocyte count (4thquartile, p = 0.02), T-cell count(4th quartile, p = 0.09), B-cell count(4th quartile, p < 0.01), B-cell% (4th quartile, p = 0.09).Rabinowtiz et al. (1990)Boston, MA1979–1987Design: cross-sectionalSubjects: infants/children (n = 1768)Outcome measures: incidence of illness inchildren was solicited from parents byquestionnaire.Analysis: relative risk of illness estimatedfrom incidence ratios, highest: combinedlower blood Pb deciles, without adjustmentfor covariates or confounders.Cord blood Pb (μg/dL)~90th %: 10Shed tooth Pb (μg/g) ~90th%: 5Relative risk (unadjusted) was elevated for the following illnesscategories: severe incidence of earinfection, 1.2 (95% CI: 1.0, 1.4),other respiratory illness, 1.5 (95% CI: 1.0, 2.3), school absence forillness other than cold or flu, 1.3 (95% CI: 1.0, 1.5).

# AX6-208Table AX6-8.1 (cont’d). Effects of Lead on Immune Function in ChildrenReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationUnited States(cont’d)Lutz et al. (1999)Springfield-Green Co,MONRDesign: cross-sectionalSubjects: children (n = 279; age range 9mo–6 yr)Outcome measures: differential blood cellcounts; lymphocyte phenotype abundance(%); and serum IL-4, soluble CD25, CD27,IgE and IgG (Rubella).Analysis: nonparametric comparison ofoutcome measures (adjusted for age) forblood Pb categories, correlationBlood Pb (μg/dL) range:1–45Blood Pb categories:<10 μg/dL, 10–14 μg/dL,15–19 μg/dL, 20–45 μg/dLSignificant association (p < 0.05) between increasing blood Pb(categorical) and increasing serum IgE levels, after adjusting for age.EuropeAnnesi-Maesano et al.(2003)France1985, 1992Design: cross-sectionalSubjects: mother/newborn pairs (n = 374),mean age 30 yrOutcome measures: maternal venous andnewborn cord serum IgE levelsAnalysis: multivariate linear regression,ANOVABlood Pb (μg/dL) mean(SD):Infant cord: 67.3 (47.8)Maternal: 96.4 (57.7)Hair Pb (ppm) mean (SD):Infant: 1.38 (1.26)Maternal: 5.16 (6.08)Significant (p < 0.0001) associationbetween increasing infant hairPb and infant cord serum IgE levels.Although medical histories were taken to identify potential IgE riskfactors (asthma, allergies) and“confounders” (e.g.,smoking), thesedo not appear to have been quantitatively integrated into theregression models. Allergy statusand blood levels were reportedlyunrelated to load biomarkers or serum IgE (basis for conclusion notreported).Karmaus et al. (2005)Germany1994–1997Design: cross-sectionalSubjects: children (n = 331, 57% male), age7–8 yrs (96%), 9–10 yrs (4%)Outcome measures: differential blood cellcount; lymphocyte phenotype abundance;and serum IgA, IgE, IgG, IgMAnalysis: multivariate linear regressionBlood Pb (μg/dL) mean(95% CI):Males: 2.5 (1.1, 4.4)Females (2.8 (1.5, 4.8)Blood Pb quartile ranges:<2.2 (n = 82)2.2–2.8 (n = 81)2.8–3.4 (n = 86)>3.4 (n = 82)Significant association between blood Pb (p < 0.05) and serum IgE(not monotonic with quartile range).Comparison of adjusted meanoutcomes (p#0.05) across blood Pb quartiles (1st quartile asreference, [+], higher, [−] lower): [−] CD3+T-cells (2nd quartile),[−] C3+CD8+T-cells (2nd quartile), [+] C3+CD5+CD19+B-cells (2ndquartile).Covariates retained: age, sex, environmental exposure to tobaccosmoke, infections (in last 12mo), serum cholesterol, andtriglycerides.

# AX6-209Table AX6-8.1 (cont’d). Effects of Lead on Immune Function in ChildrenReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationEurope(cont’d)Reigart and Graber(1976)NRNRDesign: clinicalSubjects: children (n = 19), ages 4–6 yrsOutcome measures: serum IgA, IgG, IgM,total complement and C-3, before and afterimmunization with tetanus toxoidAnalysis: none; presentation of prevalenceof clinically low, normal, and high values ofoutcome measuresBlood Pb (μg/dL) mean(range):High: >40 (n = 12): 45.3(41–51)Low:#30 (n = 7): 22.6(14–30)No apparent difference in prevalence of abnormal values for serumimmunoglobulin or complement (nostatistical analysis applied).Wagnerova et al. (1986)CzechNRDesign: longitudinal cohort (repeatedmeasures for 2-yrs)Subjects: children (n = 92, 38 females) ages11–13 yrs residing near a smelter; referencegroup (n = 67, 36 females), ages 11–13 yrsOutcome measures: serum IgA, IgE, IgG,IgMAnalysis: comparison of outcome measuresand between exposed and reference groups,stratified sex and season of samplingBlood Pb (μg/dL) mean:Pb: ~23–42Reference: ~5–22Significant (p NR, statistic NR) lower serum IgE and IgM levels inexposed group compared to reference group.Latin AmericaPineda-Zavaleta et al.(2004)MexicoNRDesign: cross-sectionalSubjects: children (n = 30 female, 35 male)ages 6–11 yrs, residing near smelterOutcome measures:mitogen- (PHA) andcytokine- (IFN-() induced nitric oxide andsuperoxide production in lymphocytesAnalysis: multivariate linear regressionBlood Pb (μg/dL) mean(range) for 3 schools:1 (n = 21): 7.0 (3.5–25.3)2 (n = 21): 20.6(10.8–49.2)3 (n = 23): 30.4(10.3–47.5)Significant (p = 0.036) association between increasing blood Pbconcentration and covariate adjusted decreasing nitric oxideproduction in PHA-activated lymphocytes (∃=−0.00089 [95% CI:−0.0017,−0.00005]).Significant (p = 0.034) association between increasing blood Pbconcentration and covariate adjusted increasing super oxideproduction in IFN-(-activated lymphocytes (∃=−0.00389 [95% CI:0.00031, 0.00748]). Covariates considered included age, sex,allergies, and blood arsenic (age, sex, and blood arsenic wereretained).Significant effect of sex on associations, significant blood Pb-arsenicinteraction.Covariates considered included age, sex, allergies, urinary arsenic(age, sex, and urinary arsenic were retained).

# AX6-210Table AX6-8.1 (cont’d). Effects of Lead on Immune Function in ChildrenReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationAsiaSun et al. (2003); Zhaoet al. (2004)ChinaNRDesign: cross-sectionalSubjects: children (n = 73) age 3–6 yrsOutcome measures: serum IgE, IgG, IgM;lymphocyte phenotype abundanceAnalysis: Nonparametric comparisons ofoutcome measures stratified by blood PbBlood Pb (μg/dL) mean(SD, range) (n = 217):9.5 (5.6, 2.6–43.7)Females: significantly higher (p <0.05) IgE levels in high blood Pbcategory (∃10 μg/dL, n = 16) compared to low category (<10 μg/dL,n = 17), and significantly lower IgG and IgM levels. A multivariateanalysis of association between blood Pb and IgE was noted but notdescribed in sufficient detail to evaluate.All children: significantly lower (p < 0.05) CD3+CD4+(%),CD3+CD8+(%), CD4+CD8+(%) in high blood Pb (∃10 μg/dL,n = 38) compared to low blood Pb (10 μg/dL, n = 35) group.

# AX6-211Table AX6-8.2. Effects of Lead on Immune Function in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited StatesPinkerton et al. (1998)U.S.NRDesign: cross-sectional cohortSubjects: adult male smelter workers(n = 145, mean age 32.9∀8.6); referencegroup, male hardware workers (n = 84, meanage 30.1∀9.3)Outcome measures: differential blood cellcounts; lymphocyte phenotype abundance;serum IgA, IgG, IgM; salivary IgA;lymphocyte proliferation (tetanus toxoid)Analysis: multivariate logistic regressionwith comparison of adjusted outcomemeasures between exposed and nonexposedgroupsBlood Pb (μg/dL) median(range)Pb: 39 (15–55)Reference: <2 (<2–12)Covariate-adjusted outcomes in Pbworkers that were significantly(p < 0.05) different from nonexposed ([+], higher, [−] lower): [−] %monocytes, [−] % CD4+CD8+cells, [−] % CD8+CD56+cells.Significant (p < 0.05) adjusted regression coefficients in exposedgroup for independent variable:blood Pb: [+] CD19+B-cells (%, no)time-integrated blood Pb: [−] serum IgG, [+] CD4+CD45RA+cells(%, number)Covariates considered in the analysis included age, race, smokinghabits, alcohol consumption, marijuana use, work shift, and variousfactors that might stimulate or suppress the immune system (e.g.,exposure to direct sunlight, sleep hrs,allergy, flu or cold symptoms).Covariates retained in the final model were age, race, work shift,smoking habits.Sarasua et al. (2000)ATSDR Multi-siteStudy: Granite City,IL, Galena, KA; Joplin,MO; Palmerton, PA1991Design: cross-sectional cohortSubjects: children and adults (n = 2036)Outcome measures: total lymphocyte count,lymphocyte phenotype abundance, serumIgA, IgG, and IgMAnalysis: multivariate linear regressionBlood Pb (μg/dL) mean(SD, 5th–95th %):6–35 mo: 7.0(16, 1.1–16.1)36–71 mo: 6.0(4.3, 1.6–14.1)6–15 yr: 4.0(2.8,1.1–9.2)16–75 yr: 4.3(2.9, 1.0–9.9)No significant association (p < 0.05) between blood Pb andoutcomes in adults (age∃16 yr).Covariates retained: age, sex,cigarette smoking, and study site.

# AX6-212Table AX6-8.2 (cont’d). Effects of Lead on Immune Function in AdultsReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationUnited States(cont’d)Fischbein et al. (1993)New YorkNRDesign: cross-sectional cohortSubjects: adult firearms instructors (n = 51),mean age 48 yr; age-matched referencesubjects (n = 36).Outcome measures:lymphocyte phenotypeabundance, lymphocyte proliferation (PHA,PWM,Staph. aureus)Analysis: comparison of outcome measuresbetween reference and blood Pb categories;multivariate linear regressionBlood Pb (μg/dL) mean(SD)Pb high (∃25): 31.4 (4.3)Pb low (<25): 14.6 (4.6)Reference: <10Outcomes in Pb workers that were significantly (p < 0.05) differentfrom reference group ([+], higher, [−] lower):[−] CD+3cells (%, number), [−] CD4+cells (%, number), [−]CD4+CD8+cells (number), [−] HLA-DR cells (number), [+] CD20+cells (%, number), [−] mitogen (PHA)-induced lymphocyteproliferation, [−] mitogen (PWM)-induced lymphocyte proliferation;[−] lymphocyte response in mixed-lymphocyte culture. No effect onantigen (Staph. aureus)-induced lymphocyte proliferation.Significant (p < 0.05) association between increasing blood Pb anddecreasing abundance of CD4+phenotypes (%), and decreasinglymphocyte proliferative response in mixed lymphocyte cultures.Covariates retained: age, sex,smoking habits, and duration ofexposure.EuropeBergeret et al. (1990)FranceNRDesign: cross-sectional cohortSubjects: adult battery smelting workers(n = 34), mean age 40 yr; reference subjects(n = 34), matched for age, sex, ethnic origin,smoking and alcohol consumption habits,intake of antibiotics, and NSAIDsOutcome measures: PMN chemotaxis(FMLP); PMN phagocytosis (opsonizedzymosan)Analysis: comparison of outcome measuresbetween worker and reference groupsBlood Pb (μg/dL) mean(SD):Pb: 70.6 (18)Reference: 9.0 (4.3)Significantly (p < 0.05) lower PMN chemotactic response (index)and phagocytic response in Pb workers.

# AX6-213Table AX6-8.2 (cont’d). Effects of Lead on Immune Function in AdultsReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationEurope(cont’d)Ewers et al. (1982)GermanyNRDesign: cross-sectional cohortSubjects: adult malebattery manufacture orsmelter workers (n = 72), mean age 36.4 yr(16–58); reference workers (n = 53), meanage 34.8 yr (21–54)Outcome measures: serum IgA, IgG, IgM,C3; saliva IgAAnalysis: parametric and nonparametriccomparison of outcome measures betweenPb workers and reference subjects; linearregressionBlood Pb (μg/dL) mean(range):Pb: 55.4.0 (18.6–85.2)Reference: 12.0 (6.6–20.8)Significantly (p < 0.05) lower serum IgM, lower salivary IgA in Pbworkers compared to reference group.Coscia et al. (1987)ItalyNRDesign: cross-sectional cohortSubjects: adult Pb workers (n = 32, 2female), mean age 42.8 yr (SD 11.5);reference subjects (n = 25), mean age 38.6 yr(SD 13.3)Outcome measures: serum IgA, IgG, IgM,C3-C4; lymphocyte phenotype abundanceAnalysis: parametric comparison ofoutcome measures between worker andreference groupsBlood Pb (μg/dL) mean(SD):Pb: 62.3 (21.6)Reference: NROutcomes in Pb workers that were significantly (p < 0.05) differentfrom reference group ([+], higher, [−] lower): [−] serum IgM, [+]serum C4, [+] lymphocyte abundance (%), [−] T-cell abundance (%,number, E-rosette forming cells), [+] B-cellabundance (%,number,immunoglobulin-bearing cells), [+] CD8+cell abundance (number).Governa et al. (1987)ItalyNRDesign: cross-sectional cohortSubjects: adult male battery manufactureworkers (n = 9), mean age 38.4 yr (SD 13.7);age-matched reference subjects (n = 18)Outcome measures: PMN chemotaxis(zymosan-activated serum)Analysis: parametric comparison ofoutcome measures between worker andreference groups, correlationBlood Pb (μg/dL) mean(SD):Pb: 63.2 (8.2)Reference: 19.2 (6.4)Significantly (p < 0.05) lowerPMN chemotactic response tozymosan activated serum. Effect magnitude was not correlated withblood Pb.

# AX6-214Table AX6-8.2 (cont’d). Effects of Lead on Immune Function in AdultsReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationEurope(cont’d)Valentino et al. (1991)ItalyNRDesign: cross-sectional cohortSubjects: adult male Pb scrap refiningworkers (n = 10), mean age 41.1 yr (SD 7.3,range 28–54); age-matched referencesubjects (n = 10)Outcome measures: PMN chemotaxis (C5 orFMLP) and phagocytosis (FMLP)Analysis: comparison of outcome measuresbetween worker and reference groups,correlationBlood Pb (μg/dL) mean(SD, range):Pb: 33.2 (5.6, 25–42)Reference: 12.6 (2.5, 8.9–18)Significantly (p < 0.002) lower PMNchemotactic response to C5 orFMLP and higher stimulated production of LT (leukotriene)B4 in Pbworkers compared to reference group. Effect magnitude correlatedwith blood Pb. No effect on phagocytic activity.Kimber et al. (1986)UKNRDesign: cross-sectional cohortSubjects: adult male TEL manufactureworkers (n = 39) mean age: 45.1 yr; andage-matched reference subjects (n = 21);mean age 32.2 yrOutcome measures: serum IgA, IgG, IgM;mitogen (PHA)-inducedlymphoblastogenesis; and NK cellcytotoxicityAnalysis: comparison of outcome measuresfor exposed and reference groupsBlood Pb (μg/dL) mean(SD, range):Pb: 38.4 (5.6, 25–53)Reference: 11.8 (2.2, 8–17)No significant (p < 0.05) differences in outcomes between exposedand reference groups.Latin AmericaQueiroz et al. (1993)BrazilNRDesign: cross-sectional cohortSubjects: adult male battery manufactureworkers (n = 39), mean age 33.9 yr (SD 12.1,range 18–56); reference subjects (n = 39)matched by age and raceOutcome measures: PMN chemotaxis(endotoxin LPS); phagocytic (endotoxinLPS) respiratory burst activity (NBTreduction)Analysis: nonparametric comparison ofoutcome measures between worker andreference groupsBlood Pb (μg/dL) range:Pb: 14.8–91.4 (>30,n = 52)Reference: <10Significantly (p < 0.001) lower chemotactic activity of PMNs, andlower phagocytic respiratory burst, in Pb workers relative toreference group.

# AX6-215Table AX6-8.2 (cont’d). Effects of Lead on Immune Function in AdultsReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationLatin America(cont’d)Queiroz et al. (1994a)BrazilNRDesign: cross-sectional cohortSubjects: adult male battery manufactureworkers (n = 60), mean age 33.9 yr (range18–56); reference subjects (n = 49) matchedby age and raceOutcome measures: PMN phagocytic/lyticactivity (opsonized yeast)Analysis: nonparametric comparison ofoutcome measures between worker andreference groupsBlood Pb (μg/dL) range:Pb: 14.8–91.4 (>30,n = 27)Reference: <10Significantly (p < 0.001) lower lytic activity of PMNs in Pb workersrelative to reference group.Queiroz et al. (1994b)BrazilNRDesign: cross-sectional cohortSubjects: adult male battery manufactureworkers (n = 33), mean age 32.4 yr (range18–56); reference subjects (n = 20) matchedby age and raceOutcome measures: serum IgA, IgG, IgM;mitogen (PHA)-induced lymphocyteproliferationAnalysis: parametric comparison ofoutcome measures between worker andreference groupsBlood Pb (μg/dL) range:Pb: 12.0–80.0 (>30,n = 27)Reference: <10No significant difference in outcomes(p < NR; SD of Pb worker andreference groups overlap) between Pbworkers and reference group.AsiaKuo et al. (2001)ChinaNRDesign: cross-sectional cohortSubjects: adult battery manufacture workers(n = 64, 21 female) 14 subject aged <40 yrand 14 subjects aged >50 yr; nonexposedreference subjects (n= 34, 17 female).Outcome measures: differential blood cellcounts, lymphocyte phenotype abundanceAnalysis: comparison of outcome measuresin exposed and reference groups,multivariate linear regressionBlood Pb (μg/dL) mean:Pb: 30Significantly (p < 0.05) adjusted mean higher monocytes (%,number), lower B cells (%), lowerlymphocytes (number), and lowergranulocytes (number) in Pb workers compared to controls.Covariates retained: age, gender,and disease status (definition notreported).

# AX6-216Table AX6-8.2 (cont’d). Effects of Lead on Immune Function in AdultsReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationAsia(cont’d)Mishra et al. (2003)IndiaNRDesign: cross-sectional cohortSubjects: adult males occupationallyexposed to Pb (n = 84), mean age 30 yr;reference subjects (n = 30), mean age 29 yrOutcome measures: serum IFN-(level,mitogen (PHA)-induced lymphocyteproliferation, NK cell cytotoxicityAnalysis: comparison of outcome measuresbetween Pb-exposed and reference groups,correlationBlood Pb (μg/dL) mean(SD, range):3-wheel drivers (n = 30):6.5 (4.7, 0.0–17.5)Battery workers (n = 34):128.1 (13.2–400.8)Jewelry makers: 17.8(18.5, 3.1–76.8)Reference: 4.5 (NR, 1.6–9.8)Significantly (p < 0.001) lower lymphocyte proliferative response toPHA in Pb-exposed groups compared to reference groups, higherIFN-(production by blood monocytes.Alomran andShleamoon (1988)IraqNRDesign: cross-sectional cohortSubjects: adult Pb (oxide) workers (n = 39),mean age 35.6 yr (9,2, SD); age-matchedreference subjects (n = 19)Outcome measures: serum IgA, IgG;mitogen (PHA, Con-A)-induced lymphocyteproliferationAnalysis: comparison of outcome measuresbetween Pb workers and reference groupBlood Pb (μg/dL) mean:Pb: 54–64Reference: NRSignificantly (p < 0.05) lower lymphocyte proliferative response toPHA or Con A in Pb workers, compared to reference group.Cohen et al. (1989)IsraelNRDesign: cross-sectional cohortSubjects: adult male occupationally Pbexposed (n = 10), age range 22–70; agematched reference subjects (n = 10)Outcome measures: mitogen (Con A, PHA)-induced-lymphocyte proliferation and Tsuppressor cell proliferation; lymphocytephenotype abundanceAnalysis: parametric comparison ofoutcome means between Pb-exposed andreference groupsBlood Pb (μg/dL) range:Exposed: 40–51Reference: <19Significantly (p < 0.02) highermitogen (Con-A)-induced suppressorcell activity. No significant (p not reported) effects on abundance ofT-cells (E-rosette-forming cells), OKT+4, OKT+8, or OKT4+/T8+ratio; mitogen (Con A or PHA)-induced lymphocyte proliferation.

# AX6-217Table AX6-8.2 (cont’d). Effects of Lead on Immune Function in AdultsReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationAsia(cont’d)Sata et al. (1998)JapanNRDesign: cross-sectional cohortSubjects: adult male Pb stearate manufactureworkers (n = 71), mean age 48 yr (range 24–74); reference subjects (n = 28), mean age 55yr (range 33–67).Outcome measures:lymphocyte phenotypeabundanceAnalysis: comparison of outcome measuresin exposed and reference groups(ANCOVA), multivariate linear regressionBlood Pb (μg/dL) mean(range):Pb: 19 (7–50)Reference: NRPb workers vs. reference: significantly (p < 0.05) covariate-adjustedlower CD3+CD45RO+(number) and higher CD8+cells (%).Significant (p < 0.05) associationbetween exposure(categorical:yes/no) and lower CD3+CD45RO+cells (number).Covariates retained: ageand cigarette smoking habits.Sata et al. (1997)JapanNRDesign: clinicalSubjects: adult male Pb smelter workers(n = 2) who underwent CaEDTA therapyOutcome measures: serum IgA, IgG, IgD,IgM; lymphocyte phenotype abundanceAnalysis: Parametric comparison ofoutcome measures before and aftertreatment, correlation of outcome means withblood PbBlood Pb (μg/dL):Subject 1: 81 μg/dL atreferral; mean beforeEDTA: 45.1 (SD 16.0);after chelation: 31.0 (9.8)Subject 2: 68 μg/dL atreferral; mean beforeEDTA: 43.3 (SD 14.1);after chelation: 33.7 (7.2)Blood Pb and outcome measures were sampled prior to and 24 hrsafter 3 CaEDTA treatments (onconsecutive days) per wk for 10wks. Comparison of mean outcome measures assessed before andafter treatments showed significantly(p < 0.05) higher IgA, IgG, andIgM; and significantly higher CD8+T-cells and CD57+NK cellsafter treatment in subject 1. Serum IgG levels in subject 1 weresignificantly correlated (r =−0.72) with blood Pb concentration.Heo et al. (2004)KoreaNRDesign: cross-sectional cohortSubjects: adults, battery manufactureworkers (n = 606; 52 females); ages: <30 yr,n = 184; >40 yr, n = 123.Outcome measures: serum IgE, IL-4, IFN(Analysis: comparison of outcomes measures(ANOVA), stratified by age and blood PbBlood Pb (μg/dL) mean(SD):<30 yr: 22.0 (10.4)30–39 yr: 23.0 (11.3)∃40 yr: 24.1 (9.3)Significantly higher (p < 0.05) serum IgE levels in blood Pbcategory (∃30 μg/dL) compared to low categories (<10 or 10–29 μg/dL).

# AX6-218Table AX6-8.2 (cont’d). Effects of Lead on Immune Function in AdultsReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationAsia(cont’d)Ünde er et al. (1996);Ba∏aran and Ünde er(2000)TurkeyNRDesign: cross-sectional cohortSubjects: adult male battery manufactureworkers (n = 25), mean age, 33 yr (22–55);reference subjects (n = 25) mean age 33 yr(22–56).Outcome measures: differential blood cellcounts; lymphocyte phenotype abundance;serum IgA, IgG, IgM, C3, and C4; neutrophilchemotaxis (zymosan-activated serum); latexparticle-induced neutrophil phagocytic (latexparticles) respiratoryburst (NBT reduction)Analysis: nonparametric and parametriccomparisons of outcome measures forexposed and reference groupsBlood Pb (μg/dL) mean(SD):Pb: 74.8 (17.8)Reference: 16.7 (5.0)Workers relative to reference: significantly (p < 0.05) lower serumIgG, IgM, C3, and C4 levels; lower CD4+(“T-helper”) abundance,lower neutrophil chemotactic response; no significant difference inCD20+(B-cell) , CD8+(“T-suppressor”) cell, CD56+(NK) cellabundance, or particle-induced NK cell respiratory burst.Yücesoy et al. (1997a)TurkeyNRDesign: cross-sectional cohortSubjects: adult male battery manufactureworkers (n = 20), ages 39–48 yr; agematched reference subjects (n = 12)Outcome measures: serum cytokines IL-1∃,IL-2, TNF∀, IFN-(Analysis: parametric and nonparametriccomparison of outcomemeasures in exposedand reference groupsBlood Pb (μg/dL) mean(SE, range):Pb: 59.4 (3.2, 42–94)Reference: 4.8 (1.0, 2–15)Significantly (p < 0.05) lower serum IL-1∃and IFN-(levels in Pbworkers compared to controls.Yücesoy et al. (1997b)TurkeyNRDesign: cross-sectional cohortSubjects: adult male battery manufactureworkers (n = 50), ages 39–48 yr; agematched reference subjects (n = 10)Outcome measures:lymphocyte phenotypeabundance, NK cell cytotoxicityAnalysis: comparison of outcome measuresin exposed and reference groupsBlood Pb (μg/dL) mean(SE, range):Pb 1 (n = 20): 59.4 (3.2,42–94)Pb 2 (n = 30): 58.4 (2.5,26–81)Reference: 4.0 (0.4, 2–6)Significantly (p < 0.05) lower CD20+B-cell (%) abundance in Pbworkers compared to controls, no difference in % CD4+T-cellabundance.

# AX6-219Table AX6-8.2 (cont’d). Effects of Lead on Immune Function in AdultsReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationAfricaAnetor and Adeniyi(1998)NigeriaNRDesign: cross-sectional cohortSubjects: adult male “Pb workers” (n = 80),mean age, 36 yr (21–66) and referencesubjects (n = 50), mean age 37 yr (22–58).Outcome measures: serum IgA, IgG, andIgM; lymphocyte countAnalysis: comparison of outcomes measuresin workers and reference group, linearregression, principal component analysisBlood Pb (μg/dL) mean(SE):Pb: 53.6 (0.95)Reference: 30.4 (1.4)Significantly lower (p < 0.05) serum IgA, IgG, and total bloodlymphocyte levels; significant associations and interactions betweenblood Pb and serum total globulins (note high blood Pb levels inreference).

# AX6-220 

# ANNEX TABLES AX6-9

# AX6-221Table AX6-9.1. Effects of Lead onBiochemical Effects in ChildrenReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited StatesMarcus and Schwartz(1987)U.S.1976–1980Design: cross-sectional national survey(NHANES II)Subjects: ages 2-6 yr (n = 1677)Outcome measures: EP,red blood cell count,mean corpuscular volume,iron status variablesAnalysis: nonlinear least squares regressionBlood Pb (μg/dL) range:6-65Non-linear regression used to fit kinetic model relating blood Pbto EP, in strata having low (<14%), medium (14-31%), or high(>31%) percent transferrin saturation (PST). Parameters in modelincluded: parameters for total red cell surface area, maximum redcell Pb concentration, equilibrium concentration ratio for plasmaand whole blood. Blood Pb increase (from 10 μg/dL) predicted todouble EP: 22 (PST < 14%), 24 (PST = 14-31%), 37(PST > 31%).Piomelli et al. (1982)New York1976Design: cross-sectionalSubjects: children (n = 2002), ages 2–12 yrOutcome measures: EPAnalysis: linear regressionBlood Pb (μg/dL) range:2–98Regression equation relating blood Pb concentration to EP(log-transformed):∀= 1.099,∃= 0.016, r = 0.509, p < 0.001Threshold for increase in EP estimated to be: 15.4 μg/dL (95%CI: 12.9, 18.2)Soldin et al. (2003)Washington DC2001–2002Design: cross-sectionalSubjects: children (n = 4908, 1812 females),age range 0–17 yrOutcome measures: EPAnalysis: locally weighted scatter plotsmoother (LOWESS)Blood Pb (μg/dL):Mean (range 1–17 yr):2.2–3.3Median (1–17 yr): 3Range: <1–103EP increases as blood Pb concentration increased above15 mg/dL. A doubling of EP occurred with an increase in bloodPb concentration of ~20 μg/dL (apolynomial expression for EP asa function of blood Pb (PbB) is:EP =−0.0015(blood Pb)3+ 0.1854(blood Pb)2−2.7554(blood Pb)+ 30.911 (r2= 0.9986)(derived from data in Table 2 of Soldin et al. (2003)EuropeRoels and Lauwerys(1987)Belgium1974–1980Design: cross-sectionalSubjects: children (n = 143), age range10–13 yrOutcome measures: ALAD, urinary ALA, EPAnalysis: linear regression, correlationBlood Pb (μg/dL) range:15–41Linear regression for EP (log-transformed) and blood Pbconcentration:∀= 1.321,∃= 0.025, r = 0.73 (n = 51)Linear regression for ALA (log-transformed) and blood Pbconcentration:∀= 0.94,∃= 0.11, r = 0.54 (n = 37)Linear regression for ALAD (log-transformed) and blood Pbconcentration:∀= 1.864,∃=−0.015, r =−0.87 (n = 143)

# AX6-222Table AX6-9.1 (cont’d). Effects of Lead on BiochemicalEffects in ChildrenReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationLatin AmericaPerez-Bravo et al.(2004)ChileNRDesign: cross-sectional;Subjects: children (n = 93, 43 males), aged 5-12 yrs who attended school near a powdered Pbstorage facilityOutcome measures: blood Hgb and Hct, ALADgenotypeAnalysis: comparison of outcome measuresbetween ALAD genotype strataBlood Pb (μg/dL) mean(SE):ALAD1 (n = 84):13.5 (8.7)ALAD2 (n = 9): 19.2 (9.5)Mean blood Pb, blood Hgb, and Hct not different between ALADgenotypes (p = 0.13).

# AX6-223Table AX6-9.2. Effects of Lead onBiochemical Effects in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationEuropeGennart et al. (1992)BelgiumNRDesign: cross-sectional cohortSubjects: adult battery manufacture workers(n = 98), mean age, 37.7 yr (range 22–55);reference group (n = 85), mean age 38.8 yr(24–55)Outcome measures:blood Hct, blood EP,urine ALAAnalysis: linear regressionBlood Pb (μg/dL) mean(SD, range):Pb: 51.0 (8.0, 40–70)Reference: 20.9(11.1, 4.4–30.0)Significant association between increasing blood Pb concentrationand increasing (log) blood EP (∀= 0.06,∃= 0.019, r = 0.87,p = 0.0001) or (log) urine ALA (∀= 0.37,∃= 0.008, r = 0.64,p < 0.0001)(No apparent analysis of covariables)Mohammed-Brahimet al. (1985)BelgiumNRDesign: cross-sectional cohortSubjects: adult smelter and ceramicsmanufacture workers (n = 38, 13 females);reference subjects (n= 100) matched withworker group by age, sex, and socioeconomicstatus.Outcome measures: blood P5N, EP, ALAD,R/ALAD (ratio of ALADbefore and afterreactivation).Analysis: comparison of outcome measures(ANOVA) between Pb workers and referencegroup; correlationBlood Pb (μg/dL) mean(SD, range):Pb: 48.5 (9.1, 27.8–66.6)Reference: 14.3(6.7, 5.6–33.6)Urine Pb (μg/g creatinine)mean (SD, range):Pb: 84.0 (95.9, 21.8–587)Reference: 10.5(8.2, 1.7–36.9)Significantly lower (p = NR) P5N in Pb workers (males or females,or combined) compared to corresponding reference groups.Correlations with blood Pb:log P5N r =−0.79 (p < 0.001)log ALAD r =−0.97 (p = NR)R/ALAD r =−0.94 (p < 0.001)log EP r = 0.86 (p = NR)Correlations with urine Pb:log P5N r =−0.74 (p = NR)log ALAD r =−0.79 (p = NR)R/ALAD r =−0.84 (p < 0.001)log EP r = 0.80 (p = NR)Roels and Lauwerys(1987)Belgium1974–1980Design: cross-sectionalSubjects: adults (n = 75, 36 females)Outcome measures: ALAD, urinary ALA, EPAnalysis: linear regression, correlationBlood Pb (μg/dL) range:adult males: 10–60adult females: 7–53Linear regression for EP (log-transformed) and blood Pbconcentration:adult male (n = 39):∀= 1.41,∃= 0.014, r = 0.74, p < 0.001adult female (n = 36):∀= 1.23,∃= 0.027, r = 0.81, p < 0.001Linear regression for ALA (log-transformed) and blood Pbconcentration:adult male (n = 39):∀= 0.37,∃= 0.006, r = 0.41, p < 0.01adult female (n = 36):∀= 0.15,∃= 0.015, r = 0.72, p < 0.001

# AX6-224Table 6-9.2 (cont’d). Effects of Leadon Biochemical Effects in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationEurope(cont’d)Grandjean (1979)DenmarkNRDesign: longitudinalSubjects: male battery manufacture workers(n = 19), mean age 32 yr (range 22–49)Outcome measures: EPAnalysis: EP and blood Pb for serialmeasurements displayed graphicallyBlood Pb (μg/dL) median(range):Group 1 (n = 5): 47.7(22.8–53.9)Group 2 (n = 5): 37.3(35.2–53.9)Five subjects (group 1) showeddeclines in EPwith decliningblood Pb (33–58 μg/dL) over a 10-mo period; 5 subjects (group 2)showed no change in EP with achange in blood Pb concentration(25–54 μg/dL) over the same period.Alessio et al. (1976)ItalyNRDesign: cross-sectionalSubjects: adult male Pb worker (n = 316), agerange NROutcome measures: blood ALAD, EP, urineALA, CPAnalysis: linear regression, correlationBlood Pb (μg/dL) range:10–150Regression relating outcomes to blood Pb concentration:ALAD (ln-transformed) (n = 169):∀= 3.73,∃=−0.031, r = 0.871ALAU (ln-transformed) (n = 316):∀= 1.25,∃= 0.014, r = 0.622UCP (ln-transformed) (n = 252):∀= 2.18,∃= 0.34, r = 0.670EP (log-transformed (males, n = 95):∀= 0.94,∃= 0.0117EP (log-transformed (females, n = 93):∀= 1.60,∃= 0.0143Cocco et al. (1995)Italy1990Design: longitudinalSubjects: adult male foundry workers(n = 40), mean age 25.1 yr (SD 2.1, range21–28)Outcome measures: serum total-, HDL- andLDL-cholesterol, blood Hgb, urine ALA,erythrocyte G6PDAnalysis: comparison of outcomes betweenpre-exposure (at start of employment,sample 1) and after 172 (range 138–217,sample 2) daysBlood Pb (μg/dL) mean(range):Sample 1: 10.0 (7–15)Sample 2: 32.7 (20–51)G6PD levels were unrelated to starting blood Pb; however, theyincreased in subjects whose bloodPb concentration increased from<30 μg/dL to >30 μg/dL or decreased from >30 μg/dL to<30 μg/dL. Increasing exposure duration was significantlyassociated with decreasing magnitude of change in G6PD.Sample 1 <30 μg/dL:∃=−0.3980 (SE 0.1761), p < 0.05Sample 1 >30 μg/dL:∃=−1.3148 (SE 0.3472), p < 0.05In the >30 μg/dL subgroup, increasing blood Pb was associatedwith decreasing magnitude of change of G6PD (∃=−2.0797[SE0.7173], p < 0.05).Serum cholesterol levels were unrelated to blood Pb concentration.

# AX6-225Table 6-9.2 (cont’d). Effects of Leadon Biochemical Effects in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationEurope(cont’d)Fracasso et al. (2002)ItalyNRDesign: cross-sectional cohortSubjects: adult battery manufacture workers(n = 37, 6 females), mean age 41 yr (SD 7);reference office workers (n = 29, 8 females),mean age 38 yr (SD 21)Outcome measures: lymphocyte DNA strandbreaks, ROS, GSHAnalysis: comparison of outcome measuresbetween Pb workers and reference group(ANOVA), logistic regressionBlood Pb (μg/dL) mean(SD):Pb: 39.6 (7.6)Reference: 4.4 (8.6)Covariate-adjusted DNA strand breaks were significantly higher inPb workers compared to the reference group andsignificantlyassociated with increased blood Pb (p = 0.011).Covariate-adjusted lymphocyte ROS was significantly higher andGSH significantly lower in the Pb workers compared to thereference group. Lower GSH levelswere significantly associatedwith increasing blood Pb concentration (p = 0.006).Odds ratios (OR) for DNA strandbreaks and lower GSH levelswere significant (Pb workers vs. reference):DNA strand breaks: OR = 1.069 (95% CI: 1.020, 1.120),p = 0.005GSH: OR = 0.634 (95% CI: 0.488, 0.824), p = 0.001ROS: OR = 1.430 (95% CI: 0.787, 2.596), p = 0.855Covariates retained: age, alcohol consumption and tobaccosmoking.Hernberg et al. (1970)PolandNRDesign: cross-sectionalSubjects: adult Pb workers (n = 166);reference group (n = 16)Outcome measures: blood ALADAnalysis: regression, correlationBlood Pb (μg/dL) range:5–95Linear regression for blood ALAD (log-transformed) and blood Pbconcentration (n = 158):∀= 2.274,∃=−0.018, r =−0.90, p < 0.001Bergdahl et al. (1997)SwedenNRDesign: cross-sectionalSubjects: adult smelter worker (n = 89);reference groups (n = 24)Outcome measures: blood Pb, erythrocyteALAD-bound Pb, ALAD genotypeAnalysis: comparison of outcome measuresBlood Pb (μg/dL) range:0.8–93Urine Pb (mg/L) range:1–112Bone Pb (μg/g) range:−19–101No association between ALAD genotype and Pb measures.Selander and Cramθr(1970)SwedenNRDesign: cross-sectionalSubjects: adult battery manufacture workers(n = 177)Outcome measures: urine ALAAnalysis: regression, correlationBlood Pb (μg/dL) range:6–90Linear regression for urine ALA (log-transformed) and blood Pbconcentration (n = 150):∀=−1.0985,∃= 0.0157, r = 0.74

# AX6-226Table 6-9.2 (cont’d). Effects of Leadon Biochemical Effects in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationEurope(cont’d)Wildt et al. (1987)SwedenNRDesign: longitudinalSubjects: adult battery manufacture workers(n = 234, 37 females) mean age 35 y (range17–70); reference group (n = 951, 471females), mean age 39 yr (range 19–67)Outcome measures: EPAnalysis: analysis ofvariability over time,linear regression, correlationBlood Pb (μg/dL) mean(range):Pb: 10–80Reference:Male: 11.3 (8–27)Female: 8.5 (5–21)Linear regression for EP (log-transformed) and blood Pbconcentration:Males (n = 851):∀= 1.21,∃= 0.0148, r = 0.72Females (n = 139):∀= 1.48,∃= 0.0113, r = 0.56AsiaHsieh et al. (2000)ChinaNRDesign: cross-sectionalSubjects: Adults in general population(n = 630, 255 females)Outcome measures:blood Hgb, Hct, RBCcount, ALAD genotypeAnalysis: comparison of outcome measuresbetween ALAD genotype strataBlood Pb (μg/dL) mean(SD):ALAD1,1 (n = 630):6.5 (5.0)ALAD1,1/2,2 (n = 30):7.8 (6.0)Mean blood Pb not different between ALAD genotype strata(p = 0.17). RBC count, Hgb, Hct not different between ALADgenotype strata (p = 0.7)Jiun and Hsien (1994)China1992Design: longitudinalSubjects: adult male Pb workers (n = 62),ages NR; reference group (n = 62, 40 females),ages NROutcome measures: plasma MDAAnalysis: comparison of outcome measuresbetween Pb workers and reference group,linear regressionBlood Pb (μg/dL) mean(SD, range):Pb: 37.2(12.5, 18.2–76.0)Reference: 13.4(7.5, 4.8–43.9)Plasma MDA levels significantly(p < 0.0001) higher (~2x) in Pbworkers whose blood Pb concentration 35 μg/dL compared to#30 μg/dL. In subjects with blood Pb >35 μg/dL, blood Pb andplasma MDA were significantly correlated:blood Pb = 9.584(MDA) + 24.412 (r = 0.85)Froom et al. (1999)Israel1980–1993Design: longitudinal surveySubjects: adult malebattery manufacturingworkers (n = 94), mean age, 38 yr (SD 9,range 26–60)Outcome measures:blood Hgb, blood EPAnalysis: multivariate linear regressionBlood Pb (μg/dL) range of13-yr individual subjectmeans:20–61 μg/dLWeak (and probably not significant) covariate-adjusted associationbetween blood Hgb and individual sample blood Pb (∃=−0.0039[SE 0.0002]), subject avg blood Pb (∃=−0.0027 [SE 0.0036]), orblood EP (∃=−0.001 [SE 0.0007])Covariates retained in model were age andsmoking habits.

# AX6-227Table 6-9.2 (cont’d). Effects of Leadon Biochemical Effects in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationAsia(cont’d)Kristal-Boneh et al.(1999)Israel1994–1995Design: cross-sectional cohortSubjects: adult male battery manufactureworkers (n = 56), mean age 43.1 yr (SD 10.6);reference group (n = 87), mean age 43.2 yr(SD 8.3)Outcome measures: serum total-, HDL-, LDL-cholesterol, HDL: total ratio, triglyceridesAnalysis: comparison of outcome measuresbetween Pb workers and reference group(ANOVA), multivariate linear regressionBlood Pb (μg/dL) mean(SD):Pb: 42.3 (14.9)Reference: 2.7 (3.6)Covariate-adjusted serum total-cholesterol (p = 0.016) and HDL-cholesterol (p = 0.001) levelswere significantly higher in Pbworkers compared to reference group. Covariates retained inANOVA: age, body mass index,season of sampling, nutritionalvariables (dietary fat, cholesterol, calcium intakes), sport activities,alcohol consumption, cigarette smoking, education, job seniority.Increasing blood Pb concentration was significantly associatedwith covariate-adjusted total cholesterol (∃= 0.130 [SE 0.054],p = 0.017) and HDL-cholesterol (∃= 0.543 [SE 0.173], p = 0.002).Covariates retained: age, body mass index. Stepwise inclusion ofother potential confounders had no effect.Solliway et al. (1996)IsraelNRDesign: cross-sectional cohortSubjects: adult male battery manufactureworkers (n = 34), mean age: 44 yr (SD 13);reference subjects (n = 56), mean age 43 yr(SD 12); cohorts constructed to have similarage, ethnic characteristics, socioeconomicstatus, education level, and occupationOutcome measures: urinary ALA, erythrocyteGSH-peroxidaseAnalysis: parametric comparison of outcomemeasures between Pband reference groups,correlationBlood Pb (μg/dL) mean(SD, range):Pb: 40.7 (9.8, 23–63)Reference: 6.7 (2.4, 1–13)Significantly lower mean erythrocyte GSH-peroxidase activity(p < 0.005) in and higher urinary ALA (p < 0.001) in Pb workerscompared to reference group.Ito et al. (1985)JapanNRDesign: cross-sectional cohortSubjects: adult male steel (smelting, casting)workers (n = 712), age range 18–59 yr;reference (office workers) group (n = 155,total), age range 40–59 yrOutcome measures: serum LPO and SOD,total and HDL-cholesterol, phospholipidAnalysis: comparison of outcome measuresbetween Pb workers and reference group,correlationBlood Pb (μg/dL) range:Pb: 5–62Reference: NRWhen stratified by age, significantly (p < 0.05) higher serum HDLcholesterol and LPO in Pb workers, age range 40–49 yr, comparedto corresponding strata of reference group. Serum lipoperoxidelevels increased as blood Pb increased above 30 μg/dL (p = NR),SOD appeared to decrease with increasing blood Pb concentration(p = NR)

# AX6-228Table 6-9.2 (cont’d). Effects of Leadon Biochemical Effects in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationAsia(cont’d)Makino et al. (1997)Japan1990–1994Design: longitudinal surveySubjects: adult male pigment or vinyl chloridestabilizer manufacture workers (n = 1573)mean age 45 yrOutcome measures:blood Hgb, Hct,RBC countAnalysis: parametric comparison of outcomemeasures, stratified by blood Pb, linearregressionBlood Pb (μg/dL) mean(SD, range):12.6 (2.0, 1–39)Urine Pb (μg/L) mean(SD, range):10.2 (2.7, 1–239)Significantly higher (p < 0.001) Hct, blood Hgb and RBC count inblood Pb category 16–39 μg/dL, compared to 1–15 μg/dLcategory.Significant positive correlation between blood Pb concentrationand Hct:∀= 42.95,∃= 0.0586 (r = 0.1553, p < 0.001), bloodHgb:∀= 14.65,∃= 0.0265 (r = 0.1835, p < 0.001) and RBCcount∀= 457,∃= 0.7120 (r = 0.1408, p < 0.001).Morita et al. (1997)JapanNRDesign: cross-sectional cohortSubjects: male Pb workers (n = 76), mean age42 yr (range 21–62); reference subjects(n = 13, 6 females), mean age, males 41 yr(range 26–52), females 45 yr (range 16–61)Outcome measures: blood NADS, ALADAnalysis: comparison of outcome measures(ANOVA) between blood Pb categories, linearregressionBlood Pb (μg/dL) mean(SD, range)Pb: 34.6 (20.7, 2.2–81.6)Significantly lower (p < 0.01) blood NADS and ALAD in blood Pbcategories >20 μg/dL compared to <20 μg/dL, with dose trend inmagnitude of difference.Significant associations between increasing blood Pb anddecreasing blood NADS andALAD in Pb workers:NADS:∀= 0.843,∃=−0.00971, r =−0.867, p < 0.001, n = 76log ALAD:∀= 1.8535,∃=−0.015, r =−0.916, p < 0.001, n = 58Oishi et al. (1996)JapanNRDesign: cross-sectionalSubjects: adult glass and pigment manufactureworkers (n = 418, 165 females), mean age 33yr (range 18–58); reference workers (n = 227,89 females), mean age 30 yr (range 17–59)Outcome measures: plasma ALA, urinaryALAAnalysis: linear regression, correlationBlood Pb (μg/dL) mean(SD, range):Pb: 48.5 (17.0, 10.3–99.4Reference: 9.6 (3.3, 3.8–20.4)Significant correlation between bloodPb concentration and plasmaand urinary ALA (both log-transformed):Plasma ALA:∀= 0.327,∃= 0.022, r = 0.742UrinaryALA:∀=−0.387,∃= 0.022, r = 0.711Significant correlation between plasma and urinary ALA:∀= 6.038,∃= 4.962, r = 0.897

# AX6-229Table 6-9.2 (cont’d). Effects of Leadon Biochemical Effects in AdultsReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationAsia(cont’d)Sugawara et al. (1991)JapanNRDesign: cross-sectional cohortSubjects: adult Pb workers and referencegroup (n = 32, total), ages NROutcome measures: plasma and erythrocytelipoperoxide and SOD; erythrocyte CAT,GSH, and methemoglobinAnalysis: comparisons of outcome measuresbetween Pb workers and reference group,linear regression and correlationBlood Pb (μg/dL) mean(SD, range):Pb: 57.1 (17.6, 20–96)Reference: NRSignificantly (p < 0.01) higher erythrocyte LPO and lower SOD,CAT and GSH levels in workers compared to reference group.Erythrocyte lipoperoxide (r = 0.656) and GSH (r =−0.631) weresignificantly correlated with blood Pb.Kim et al. (2002)Korea1996Design: cross-sectional cohortSubjects: adult male secondary Pb smelterworkers (n = 83), mean age: 38.7 yr (SD10.8); reference subjects (n = 24), mean age:32.0 (SD 10.8)Outcome measures:blood Hgb, blood ALAD,blood EP, blood P5NAnalysis: parametric comparison (ANOVA)of outcome measures between Pb workers andreference group, correlation, multivariatelinear regressionBlood Pb (μg/dL) mean(SD)Pb: 52.4 (17.7)Reference: 6.2 (2.8)Significantly (p < 0.05) lowerblood P5N, ALAD, and Hgb; andhigher blood EP in Pb workers compared to controls.Significant (p < 0.001) correlations (in Pb worker group) withblood Pb: P5N (r =−0.704), log EP (r = 0.678), log ALAD(r =−0.622).Significant association between increasing EP and decreasingblood Hgb:blood Pb∃60 μg/dL:∃=−1.546 (95% CI:−2.387,−0.704),r2= 0.513, p = 0.001blood Pb <60 μg/dL:∃=−1.036 (95% CI:−1.712,−0.361),r2= 0.177, p = 0.003Significant association between increasing P5N and increasingblood Hgb (high blood Pb group only):blood Pb∃60 μg/dL:∃= 0.222 (95% CI: 0.015, 0.419),r2= 0.513, p = 0.036Covariates included in model: P5N, log serum ferritin, log EPLee et al. (2000)KoreaNRDesign: cross-sectional cohortSubjects: adult male Pb workers (n = 95;secondary smelter,PVC-stabilizermanufacture, battery manufacture); mean age42.8 yr (SD 9.3, range 19–64); reference group(n = 13), mean age 35.1 yr (SD 9.9, range22–54)Outcome measures: urinary ALA, EPAnalysis: correlationBlood Pb (μg/dL) mean(SD, range):Pb: 44.6 (12.6, 21.4–78.4)Reference: 5.9(1.2, 4.0–7.2)Significant correlation betweenincreasing DMSA-provokedurinary Pb and urinary ALA (r = 0.31, p < 0.002) and EP (r = 0.35,p < 0.001).

# AX6-230Table 6-9.2 (cont’d). Effects of Leadon Biochemical Effects in AdultsReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationAsia(cont’d)Schwartz et al. (1997)Korea1994-1995Design: cross-sectionalSubjects: adult male battery manufactureworkers (n = 57), mean age 32 yrs (SD 6).Outcome measures: blood Hgb, HgbA1, andHgbA2, ALAD genotypeAnalysis: comparison of outcome measuresbetween ALAD genotype strataBlood Pb (μg/dL) mean(SD):ALAD1,1 (n = 38): 26.1(9.8)ALAD1,2 (n = 19): 24.0(11.3)Mean blood Pb (p = 0.48) and blood Hgb levels (p = 0.34) werenot different between ALAD genotype strata.Gurer-Orhan et al.(2004)TurkeyNRDesign: cross-sectional cohortSubjects: adult male battery manufactureworkers (n = 20), mean age 35 yr (SD 8);reference workers (n = 16), mean age32 yr (SD 9)Outcome measures: blood ALAD, EP,erythrocyte MDA, CAT, G6PD, bloodGSH:GSSGAnalysis: comparison of outcome measuresbetween Pb workers and reference group,correlationBlood Pb (μg/dL) mean(SD):Pb: 54.6 (17)Reference: 11.8 (3.2)Significant correlation between blood Pb concentration and bloodALAD (r = -0.85, p < 0.0001) and EP (r = 0.83, p < 0.001).Significant correlation betweenblood Pb concentration anderythrocyte MDA (r = 0.80, p = <0.0001), erythrocyte G6PD(r = 0.70, p < 0.0001, erythrocyte CAT (r = 0.62, p < 0.001), bloodGSH (r = 0.64, p < 0.0005), blood GSSG (r = 0.67, p < 0.0001).GSH: GSSG ratio lower (p = NR) in Pb workers (3.2), comparedto controls (8.0).Süzen et al. (2003)TurkeyNRDesign: cross-sectionalSubjects: Male Pb battery manufactureworkers (n = 72), age range 24-45 yrs.Outcome measures: blood ALAD, urine ALA,ALAD genotypeAnalysis: comparison of outcome measuresbetween ALAD genotype strataBlood Pb (μg/dL) mean(SD, range):All: 34.5 (12.8, 13.4–71.8)ALAD1,1 (n = 51)34.4 (13.1, 13.4–71.8)ALAD2 (n = 21)34.9 (12.6, 19.2–69.6)Mean blood Pb concentration (p = 0.88) and blood ALAD activity(p = 0.33) were not differentbetween ALAD genotype strata.Mean urinary ALA was significantly higher (p < 0.05) in theALAD1,1 stratum.

# AX6-231Table AX6-9.3. Effects of Lead onHematopoietic System in ChildrenReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationUnited StatesLiebelt et al. (1999)ConnecticutNRDesign: cross-sectionalSubjects: children (n =86, 31 female), ages1–6 yrOutcome measures: serum EPO, blood HgbAnalysis: ANOVA of outcome measuresstratified by blood Pb, linear regressionBlood Pb (μg/dL) median(range):18 (2–84)84% <35Significant association between increasing blood Pb concentrationand decreasing serum EPO concentration (∃=−0.03, p = 0.02).Covariates included in model were blood Hgb (∃=−1.36, p < 0.01)(age was not included), r2= 0.224. Predicted decrease in serum EPOper 10 μg/dL was 0.03 mIU/mL. Nosignificant association betweenblood Pb and blood Hgb.Schwartz et al. (1990)Idaho1974Design: cross-sectionalSubjects: children (n = 579), ages 1–5 yr,residing near an active smelter (withuncontrolled emissions)Outcome measures: HctAnalysis: logistic regressionBlood Pb (μg/dL) range:11–164Significant association between increasing blood Pb concentrationand probability of anemia (Hct < 35%) (∃1= 0.3083 [SE 0.0061])and age (∃2=−0.3831 [SE 0.1134]). A 10% probability of anemiawas predicted to be associatedwith blood Pb concentration of~20 μg/dL at age 1 yr, 50 μg/dL at age 3 yr, and 75 μg/dL at age 5yrs (from Fig. 2 Schwartz et al. (1990).Regression model relating Hct to blood Pb (BL μg/dL) and age(AGE, yr): Hct = A/[1 + exp(∃0+∃1BL +∃2AGE)]:A = 39.42 (SE 0.79), p = 0.0001∃0=−3.112 (SE 0.446), p = 0.0001∃1= 0.0133 (SE 0.0041), p = 0.0005∃2=−0.2016 (SE 0.0905), p = 0.0129Based on above model, a 10% decrease in hematocrit (from 39.5 to35.5%) is predicted in association with blood Pb concentrations of85, 115, and 145 μg/dL, at ages 1, 3, and 5 yrs, respectively.

# AX6-232Table AX6-9.3 (cont’d.). Effects of Leadon Hematopoietic System in ChildrenReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationEuropeGraziano et al. (2004)(Factor Litvak et al.(1999, 1998)Yugoslavia1985–1998Design: prospectiveSubjects: children (n = 311; age range4.5–12 yr) from high-Pb (smelter/refinery)and low-Pb areasOutcome measures:blood Hgb, serum EPO.Analysis: multivariate linear regression(GEE for repeated measures)Blood Pb (μg/dL) range:4.5 yr: 4.6–73.16.5 yr: 3.1–71.79.0 yr: 2.3–58.1Blood Pb (μg/dL) meansfor ages 4.5–12 yrs:High Pb: 30.6–39.3Low Pb: 6.1–9.0Significant association between increasing blood Pb concentrationand increasing serum EPO concentration at ages 4.5 (p < 0.0001)and 6.5 yr (p < 0.0007), with decreasing regression slope with age:4.5 yr:∃= 0.21 (SE 0.043), p = 0.0001; 6.5 yr:∃= 0.11 (SE 0.41),p = 0.0103; 9.5 yr:∃= 0.029 (SE 0.033), p = 0.39; 12 yr:∃= 0.016(SE 0.031), p = 0.60.Covariates retained in regression model were age (∀), blood Pb (∃),and blood Hgb ((). GEE for repeated measures yielded (FactorLitvak et al., 1998, updatedfrom personal communication fromGraziano 07/2005):(: 0.6097 (95% CI:−0.0915,−0.0479), p < 0.00014.5 yr:∀= 1.3421 (95% CI: 1.0348, 1.6194), p < 0.0001∃= 0.2142 (95% CI: 0.1282, 0.3003), p < 0.00016.5 yr:∀= 1.6620 (95% CI: 1.3737, 1.9503), p < 0.0001∃= 0.1167 (95% CI: 0.0326, 0.2008), p < 0.0019.5 yr:∀= 1.7639 (95% CI: 1.4586, 2.0691), p < 0.0001∃= 0.0326 (95% CI:−0.0346, 0.0998), p = 0.164512 yr:∀= 1.8223 (95% CI: 1.524, 2.1121), p < 0.0001∃= 0.0112 (95% CI:−0.0359, 0.0584), p = 0.1645Based on the GEE, the predictedincrease in serum EPO per 10μg/dL increase in blood Pb concentration (at Hgb = 13 g/dL) \ was:1.25 mIU/mL (36%) at age 4.5 yr and 1.18 (18%) at age 6.5 yr.Blood Hgb levels were not significantly different in children fromhigh-Pb area (mean 25–38 μg/dL) compared to low-Pb area (mean5–9 μg/dL).

# AX6-233Table AX6-9.3 (cont’d). Effects of Leadon Hematopoietic System in ChildrenReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationLatin AmericaPerez-Bravo et al.(2004)ChileNRDesign: cross-sectional;Subjects: children (n = 93, 43 males), aged5-12 yrs who attended school near apowdered Pb storage facilityOutcome measures:blood Hgb and Hct,ALAD genotypeAnalysis: comparison of outcome measuresbetween ALAD genotype strataBlood Pb (μg/dL) mean(SE):ALAD1 (n = 84): 13.5(8.7)ALAD2 (n = 9): 19.2 (9.5)Mean blood Pb, blood Hgb, and Hct not different between ALADgenotypes

# AX6-234Table AX6-9.4. Effects of Lead onHematopoietic System in AdultsReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationUnited StatesHu et al. (1994)U.S.1991Design: surveySubjects: adult male carpentry workers(n = 119), mean age: 48.6 yr (range 23–67)Outcome measures:blood Hct, blood HgbAnalysis: multivariate linear regressionBlood Pb (μg/dL) mean(SD, range):8.3 (4.0, 2–25)Bone Pb (μg/g) mean(SD, range)Tibia: 9.8 (9.5,−15 to 39)Patella: 13.9 (16.6,−11 to78)Significant association between increasing patella bone Pb anddecreasing covariate adjusted blood Hgb (∃=−0.019 [SE 0.0069],p = 0.008, r2= 0.078) and blood Hct (∃=−0.052 [SE 0.019],p = 0.009, r2= 0.061). After adjustment for bone Pb measurementerror, a 37 μg/dL increase in patella bone Pb level (from the lowestto highest quintile) was associated with a decrease in blood Hgb andHct of 11 g/L (95% CI: 2.7, 19.3) and 0.03 (95% CI: 0.01, 0.05),respectively.Covariates considered: age, bodymass index, tibia Pb, patella Pb,blood Pb, current smoking status, alcohol consumptionCovariates retained: patella bonePb, alcohol consumption, bodymass index.EuropeOsterode et al. (1999)AustriaNRDesign: cross-sectional cohortSubjects: adult male Pb workers (n = 20),ages 46 yr (SD, 7); age-matched referencegroup (n = 20)Outcome measures:blood PCV, blood Hgb,serum EPO, blood erythroid progenitor(BFU-E) cell count, blood pluripotentprogenitor (CFU-GEMM) cell count, bloodgranulocyte/macrophage progenitor (CFUGM) cell count.Analysis: parametric and nonparametriccomparison of outcomes between Pb workersand reference group; correlationBlood Pb (μg/dL) mean(range):Pb: 45.5 (16–91)Reference: 4.1 (3–14)Urine Pb (μg/L) mean(range):Pb: 46.6 (7–108)Reference: 3.7 (2–16)Significantly lower (p < 0.001) BFU-E counts in Pb workers whohad blood Pb concentrations∃60 μg/dL, compared to referencegroup. Significant negative correlation between blood Pb or urinePb and CFU-GM and CFU-E. Serum EPO was not correlated withHct in Pb workers, however, serum EPO increased exponentiallywith decrease in Hct in reference group.

# AX6-235Table AX6-9.4 (cont’d). Effects of Leadon Hematopoietic System in AdultsReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationEurope(cont’d)Gennart et al. (1992)BelgiumNRDesign: cross-sectional cohortSubjects: adult battery manufacture workers(n = 98), mean age, 37.7 yr (range 22–55);reference group (n = 85), mean age 38.8 yr(24–55)Outcome measures:blood Hgb, RBC count,Hct, blood EPAnalysis: linear regressionBlood Pb (μg/dL) mean(SD, range):Pb: 51.0 (8.0, 40–70)Reference: 20.9 (11.1, 4.4–30.0)Significant association between increasing blood Pb concentrationand decreasing blood Hgb (∃=−0.011, r = 0.22, p = 0.003) or Hct(∃= -0.035, r = 0.24, p < 0.01).Significant association between increasing blood Pb concentrationand increasing blood EP (∃= 0.0191, r = 0.87, p = 0.0001)(No apparent analysis of covariables).Mohammed-Brahimet al. (1985)BelgiumNRDesign: cross-sectional cohortSubjects: adult smelter and ceramicsmanufacture workers (n = 38, 13 females);reference subjects (n= 100) matched withworker group by age, sex, andsocioeconomic statusOutcome measures: blood P5N, EP, ALAD,R/ALAD (ratio of ALADbefore and afterreactivation).Analysis: comparison of outcome measures(ANOVA) between Pb workers andreference group; correlationBlood Pb (μg/dL) mean(SD, range):Pb: 48.5 (9.1, 27.8–66.6)Reference: 14.3 (6.7, 5.6–33.6)Urine Pb (μg/g creatinine)mean (SD, range):Pb: 84.0 (95.9, 21.8–587)Reference: 10.5 (8.2, 1.7–36.9)Significantly lower (p = NR) P5N in Pb workers (males or females,or combined) compared to corresponding reference groups.Correlations with blood Pb:log P5N r =−0.79 (p < 0.001)log ALAD r =−0.97 (p = NR)R/ALAD r =−0.94 (p < 0.001)log EP r = 0.86 (p = NR)Correlations with urine Pb:log P5N r =−0.74 (p = NR)log ALAD r =−0.79 (p = NR)R/ALAD r =−0.84 (p < 0.001)log EP r = 0.80 (p = NR)Hajem et al. (1990)FranceNRDesign: cross-sectionalSubjects: adult males (n = 129), mean age36 yr (SD 7.8, range 24–55), with noenvironmental exposure to PbOutcome measures: erythrocyte membraneactivities of Na+-K+-ATPase, Na+-K+-cotransport, Na+-Li+-antiport, and passive Na+and K+ permeabilityAnalysis: linear regression, correlationBlood Pb (μg/dL)geometric mean (95% CI,range):16.0 (15.2–16.8, 8.0–33.0)Hair Pb (μg/g)geometricmean (95% CI, range):5.3 (4.44–6.23, 0.9–60)Na+-K+-co-transport activity negatively correlated with blood Pbconcentration (r =−0.23, p = 0.02); linear regression:∀= 583.19,∃=−170.70Na+-K+-ATPase activity negatively correlated with hair Pb(r =−0.18, p = 0.04); simple linear regression:∀= 3.34,∃=−0.02

# AX6-236Table AX6-9.4 (cont’d). Effects of Leadon Hematopoietic System in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationEurope(cont’d)Poulos et al. (1986)GreeceNRDesign: cross-sectional cohortSubjects: adult male cable productionworkers who were exposed to Pb (worker 1;n = 50, mean age 37 yr); male cable workerswho had not direct contact with Pb (worker2, n = 75, mean age 36.5 yr); reference group(n = 35, mean age 39 yr)Outcome measures:blood Hgb, HctAnalysis: simple linear regression in theform: mean Hct = a +∃(individual Hct –group mean Hct)Blood Pb (μg/dL) mean(SE):Worker 1: 27.0 (0.7)Worker 2: 18.3 (0.6)Reference: 21.5 (1.5)Significant association between increasing blood Pb and decreasingHct:Worker 1:∀= 46.50,∃=−0.170 (SE 0.079), p < 0.05Worker 2:∀= 44.57,∃=−0.180 (SE 0.083), p < 0.05Reference:∀= 44.69,∃=−0.255 (SE 0.044), p < 0.001Significant association between increasing blood Pb and decreasingblood Hgb:Worker 1:∀= 15.23,∃=−0.058 (SE 0.028), p < 0.05Worker 2:∀= 14.58,∃=−0.071 (SE 0.034), p < 0.05Reference:∀= 14.64,∃=−0.087 (SE 0.015), p < 0.001Romeo et al. (1996)ItalyNRDesign: cross-sectional cohortSubjects: adult male Pb workers (n = 28),age range, 17–73; reference group (n = 113),age range, 21–75 yrOutcome measures: serum EPO, blood HgbAnalysis: nonparametric comparison ofoutcome measures between Pb workers andreference group; correlationBlood Pb (μg/dL) mean(SD, range):Pb 1: 32.3 (5.6, 30–49)Pb 2: 65.1 (16, 50–92)Reference: 10.4 (4.3, 3–20)Significantly (p = 0.021) lower serum EPO in Pb workers comparedto reference group. No significant(p < 0.05) Pb effect on bloodHgb.Graziano et al. (1990)Yugoslavia1986Design: prospectiveSubjects: pregnant women (n = 1502) fromhigh-Pb (smelter/refinery) and low-Pb areasOutcome measures: HgbAnalysis: comparison of outcome measuresbetween high-and low-Pb groupsBlood Pb (μg/dL) mean(95% CI):High Pb: 17.1 (6.9, 42.6)Low Pb: 5.1 (2.5, 10.6)Mean blood Hgb levels (g/dL) in high-Pb group (12.4; 95% CI:10.3, 14.5) not different from low-Pb group (12.3; 95% CI: 10.0,14.7).

# AX6-237Table AX6-9.4 (cont’d). Effects of Leadon Hematopoietic System in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationEurope(cont’d)Graziano et al. (1990)Yugoslavia1986Design: prospectiveSubjects: pregnant women (n = 48) fromhigh-Pb (smelter/refinery) and low-Pb areas(6 highest and lowest mid-pregnancy bloodPb concentrations), within each of 4 Hgbstrata (g/dL): 9.0–9.9, 10.0–10.9, 11.0–11.9,12.0–12.9Outcome measures: Hgb, EPOAnalysis: ANOVA of outcome measures insubjects stratified by blood Pb and bloodHgbBlood Pb (μg/dL) meanrange for Hgb strataHigh Pb: 16.9–38.6Low Pb: 2.4–3.6Significant effect of blood Pb (p = 0.049) and blood Hgb (p = 0.001)on mid-term and term serum EPO (blood Pb p = 0.055, Hgbp = 0.009), with significantly lower serum EPO associated withhigher blood Pb.AsiaHsiao et al. (2001)China1989–1999Design: longitudinalSubjects: adult battery manufacture workers(n = 30, 13 females), mean age 38.3 yrOutcome measures:blood Hgb, Hct,RBC countAnalysis: GEE for repeated measures(models: linear correlation, thresholdchange, synchronous change, lag change);logistic regressionBlood Pb (μg/dL) mean:1989: 601999: 30Significant association between increasing blood Pb and increasingRBC count and Hct:Odds ratios (95% CI):Synchronous change model:Blood Hgb: 0.95 (0.52, 1.78)RBC count: 3.33 (1.78, 6.19)Hct: 2.19 (1.31, 3.66)Lag change:Blood Hgb: 1.70 (0.99, 2.92)RBC count: 2.26 (1.16, 4.41)Hct: 2.08 (1.16, 4.41)Hsieh et al. (2000)ChinaNRDesign: cross-sectionalSubjects: Adults in general population(n = 630, 255 females)Outcome measures:blood Hgb, Hct, RBCcount, ALAD genotypeAnalysis: comparison of outcome measuresbetween ALAD genotype strataBlood Pb ( μg/dL) mean(SD):ALAD1,1 (n = 630):6.5 (5.0)ALAD1,1/2,2 (n = 30):7.8 (6.0)Mean blood Pb not differentbetween ALAD genotype strata(p = 0.17). RBC count, Hgb, Hct not different between ALADgenotype strata (p = 0.7).

# AX6-238Table AX6-9.4 (cont’d). Effects of Leadon Hematopoietic System in AdultsReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationAsia(cont’d)Froom et al. (1999)Israel1980–1993Design: longitudinal surveySubjects: adult malebattery manufacturingworkers (n = 94), mean age, 38 yr (SD 9,range 26–60)Outcome measures:blood Hgb, blood EPAnalysis: multivariate linear regressionBlood Pb (μg/dL) range of13-yr individual subjectmeans: 20–61 μg/dLWeak (and probably not significant) covariate-adjusted associationbetween blood Hgb and individual sample blood Pb (∃=−0.0039[SE 0.0002]), subject avg blood Pb (∃=−0.0027 [SE 0.0036]) orblood EP (∃=−0.001 [SE 0.0007]).Covariates retained in model were age andsmoking habits.Solliway et al. (1996)IsraelNRDesign: cross-sectional cohortSubjects: adult male battery manufactureworkers (n = 34), mean age: 44 yr (SD 13);reference subjects (n = 56), mean age 43 yr(SD 12); cohorts constructed to have similarage, ethnic characteristics, socioeconomicstatus, education level, and occupationOutcome measures:blood Hgb, RBC countAnalysis: parametric comparison ofoutcome measures between Pb and referencegroups, correlationBlood Pb (μg/dL) mean(SD, range):Pb: 40.7 (9.8, 23–63)Reference: 6.7 (2.4, 1–13)Significantly lower (p < 0.05) mean RBC count in Pb workerscompared to reference group.Significant negative correlationbetween blood Pb concentration and RBC count (r =−0.29,p < 0.05). Mean comparison for blood Hgb (p = 0.4); correlationwith blood Pb concentration (r =−0.05, p = 0.7).Horiguchi et al. (1991)JapanNRDesign: cross-sectional cohortSubjects: adult male secondary Pb refineryworkers (n = 17), mean age: 44.9 yr (range24–58); reference male subjects (n = 13),mean age: 33.5 yr (range 22–44)Outcome measures: RBC deformability(microfiltration at−20 cm H2O pressure),RBC count, Hct, blood HgbAnalysis: comparisons of outcome measuresbetween Pb workers and reference groupBlood Pb (μg/dL) mean(SD):Pb: 53.5 (16.1)Reference: NRUrine Pb (μg/L) mean(SD):Pb: 141.4 (38.1)Reference: NRSignificantly lower RBC deformability (p < 0.01), RBC count(p < 0.01) Hct (p < 0.01), and blood Hgb (p > 0.001) in Pb workerscompared to reference group.

# AX6-239Table AX6-9.4 (cont’d). Effects of Leadon Hematopoietic System in AdultsReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationAsia(cont’d)Makino et al. (1997)Japan1990–1994Design: longitudinal surveySubjects: adult male pigment or vinylchloride stabilizer manufacture workers(n = 1573) mean age 45 yrOutcome measures:blood Hgb, Hct, RBCcountAnalysis: parametric comparison ofoutcome measures, stratified by blood Pb,linear regressionBlood Pb (μg/dL) mean(SD, range):12.6 (2.0, 1–39)Urine Pb (μg/L) mean (SD,range):10.2 (2.7, 1–239)Significantly higher (p < 0.001) Hct, blood Hgb, and RBC count inblood Pb category 16–39 μg/dL, compared to 1–15 μg/dL category.Significant positive correlation between blood Pb concentration andHct:∀= 42.95,∃= 0.0586 (r = 0.1553, p < 0.001), blood Hgb:∀= 14.65,∃= 0.0265 (r = 0.1835, p < 0.001), and RBC count∀= 457,∃= 0.7120 (r = 0.1408, p < 0.001).Morita et al. (1997)JapanNRDesign: cross-sectional cohortSubjects: male Pb workers (n = 76), meanage 42 yr (range 21–62); reference subjects(n = 13, 6 females), mean age, males 41 yr(range 26–52), females 45 yr (range 16–61)Outcome measures: blood NADS, ALADAnalysis: comparison of outcome measures(ANOVA) between blood Pb categories,linear regressionBlood Pb (μg/dL) mean(SD, range)Pb: 34.6 (20.7, 2.2–81.6)Significantly lower (p < 0.01) blood NADS and ALAD in blood Pbcategories >20 μg/dL compared to <20 μg/dL, with dose trend inmagnitude of difference.Significant associations between increasing blood Pb and decreasingblood NADS and ALAD in Pb workers:NADS:∀= 0.843,∃=−0.00971, r =−0.867, p < 0.001, n = 76logALAD:∀= 1.8535,∃=−0.015, r =−0.916, p < 0.001, n = 58Kim et al. (2002)Korea1996Design: cross-sectional cohortSubjects: adult male secondary Pb smelterworkers (n = 83), mean age: 38.7 yr (SD10.8); reference subjects (n = 24), mean age:32.0 (SD 10.8)Outcome measures:blood Hgb, bloodALAD, blood EP, blood P5NAnalysis: parametric comparison (ANOVA)of outcome measures between Pb workersand reference group, correlation, multivariatelinear regressionBlood Pb (μg/dL) mean(SD)Pb: 52.4 (17.7)Reference: 6.2 (2.8)Significantly (p < 0.05) lowerblood P5N, ALAD, and Hgb; andhigher blood EP in Pb workers compared to controls.Significant (p < 0.001) correlations (in Pb worker group) with bloodPb: P5N (r =−0.704), log EP (r = 0.678), log ALAD(r = -0.622).Significant association between increasing EP and decreasing bloodHgb:blood Pb∃60 μg/dL:∃=−1.546 (96% CI:−2.387,−0.704),r2= 0.513, p = 0.001blood Pb <60 μg/dL:∃=−1.036 (96% CI:−1.712,−0.361),r2= 0.177, p = 0.003Significant association between increasing P5N and increasing bloodHgb (high blood Pb group only):blood Pb∃60 μg/dL:∃= 0.222 (96% CI: 0.015, 0.419), r2= 0.513,p = 0.036Covariates included in model: P5N, log serum ferritin, log EP

# AX6-240Table AX6-9.4 (cont’d). Effects of Leadon Hematopoietic System in AdultsReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationAsia(cont’d)Schwartz et al. (1997)Korea1994-1995Design: cross-sectionalSubjects: adult male battery manufactureworkers (n = 57), mean age 32 yrs (SD 6).Outcome measures: blood Hgb, HgbA1, andHgbA2, ALAD genotypeAnalysis: comparison of outcome measuresbetween ALAD genotype strataBlood Pb (μg/dL) mean(SD):ALAD1,1 (n = 38): 26.1(9.8)ALAD1,2 (n = 19): 24.0(11.3)Mean blood Pb (p = 0.48) and blood Hgb levels (p = 0.34) were notdifferent between ALADgenotype strata.

# AX6-241Table AX6-9.5. Effects of Lead on the Endocrine System in ChildrenReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationUnited StatesMahaffey et al. (1982)Wisconsin, New YorkNRDesign: cross-sectionalSubjects: children/adolescents (n = 177),ages 1–16 yrOutcome measures: serum 1,25-OH-DAnalysis: comparison of outcome measuresbetween age, location and blood Pb strata,linear regressionBlood Pb (μg/dL) range:12–120Serum 1,25-OH-D levels were significantly (p = 0.05) higher in theage group 11–16 yr compared to age groups 1–5 or 6–10 yr.Increasing blood Pb (log-transformed)significantly associated withdecreasing serum 1,25-OH-D levels in children 1–5 yr of age(∀= 74.5,∃=−34.5, r =−0.884, n = 50)Dietary calcium: NRRosen et al. (1980)New YorkNRDesign: cross-sectionalSubjects: children (n = 45), ages 1–5 yrOutcome measures: serum calcium, PTH,25-OH-D, 1,25-OH-DAnalysis: comparison of outcome measuresbetween blood Pb strata, and before and afterchelation, correlationBlood Pb (μg/dL) mean(SE, range):#29 (n = 15): 18(1, 10–26)30–59 (n = 18): 47(2, 33–55)∃60 (n = 12): 74(98, 62–120)Significantly higher serum PTH levels and lower 25-OH-D in highPb group compared to low-Pb group; significantly lower 1,25-OH-Dlevels in moderate- and high-Pb group compared to low-Pb group.Serum levels of 1,25-OH-D werenegatively correlated with bloodPb (high Pb: r =−0.71, moderate: r =−0.63, p < 0.01). Afterchelation therapy, blood Pb decreased and serum 1,25-OH-D levelsincreased to levels not significantly different (p > 0.1) from low-Pbgroup, 25-OH-D levels were unchanged.Dietary calcium intake (mg/day) mean (SE):Low Pb: 800 (30)Moderate Pb: 780 (25)High Pb: 580 (15)Sorrell et al. (1977)New York1971–1975Design: cross-sectionalSubjects: children (124), ages 1–6 yrOutcome measures: serum calcium,phosphate, 25-OH-DAnalysis: comparison of outcome measuresbetween blood Pb strata, correlationBlood Pb (μg/dL) mean(SE):#29 (n = 40): 23 (1)30–59 (n = 35): 48 (1)∃60 (n = 49): 84 (5.0)Serum calcium and 25-OH-D weresignificantly lower in high Pbgroup (p < 0.001). Significant negative correlation between bloodPb and serum calcium (high Pb, r =−0.78, p < 0.001) or calciumintake high Pb, (r =−0.82, p < 0.001) in all three Pb strata. Serum25-OH-D was significantly positively correlated with vitamin Dintake, but not with blood Pb.Dietary calcium intake (mg/day) mean (SE):Low Pb: 770 (20)Moderate Pb: 760 (28)High Pb: 610 (20)

# AX6-242Table AX6-9.5 (cont’d). Effects of Leadon the Endocrine System in ChildrenReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationUnited States(cont’d)Siegel et al. (1989)Connecticut1987Design: cross-sectionalSubjects: children (n =68, 32 female), ages11 mo to 7 yrOutcome measures: serum FT4, TT4Analysis: linear regressionBlood Pb (μg/dL) mean(range):25 (2–77)No significant association between blood Pb concentration andthyroid hormone outcomes. Linear regression parameters:FT4:∀= 1.55 (SE 0.05),∃= 0.0024 (SE 0.0016), r2= 0.03,p = 0.13TT4:∀= 8.960 (SE 0.39),∃= 0.0210 (SE 0.0127), r2= 0.04,p = 0.10Koo et al. (1991)OhioNRDesign: longitudinal (subset of prospective)Subjects: children (n = 105, 56 females), age21, 27, 33 moOutcome measures: serum calciummagnesium, phosphorus, PTH, CAL, 25-OHD, 1,25-OH-D, and bonemineral contentAnalysis: structural equation modelingBlood Pb (μg/dL)geometric mean(GSD, range):Lifetime mean, based onquarterly measurements:9.74 (1.44, 4.8–23.6)Concurrent:15.01 (1.52, 6–44)Maximum observed:18.53 (1.53, 6–63)Significant association between increasing blood Pb (ln-transformed)and covariate-adjusted decreasing serum phosphorus(∀= 1.83,∃=−0.091). No other covariate-adjusted outcomes weresignificantly associated with blood Pb.Covariates retained: age, sex, race, and sampling season.Dietary calcium intake (mg/day)#600: n = 4 (4%)600–1200: n = 58 (55%)>1200: n = 43 (41%)

# AX6-243Table AX6-9.6. Effects of Lead onthe Endocrine System in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationUnited StatesCullen et al. (1984)Connecticut1979NRDesign: clinical case studySubjects: adult males with neurologicalsymptoms of Pb poisoningOutcome measures: serum, FSH, LH, PRL,TESAnalysis: clinical outcomes in terms ofabnormal valuesBlood Pb (μg/dL) range:66–139Five subjects with defectsin spermatogenesis (includingazospermia), with no change in basal serum FSH, LH,PRL, and TES.Robins et al. (1983ConnecticutNRDesign: cross-sectionalSubjects: adult male brass foundry workers(n = 47), age range 20–64 yrOutcome measures: FT4Analysis: simple linear regression withstratification by age and race.Blood Pb (μg/dL) range:16–127Significant association between increasing blood Pbconcentration and decreasing FT4 (∀= 1.22,∃=−0.0042 [95% CI:−0.0002,−0.0082], r2= 0.085,p = 0.048). Significant interaction between race (black,white) and blood Pb.When stratified by race:Black:∀= 1.13,∃=−0.0051 (95% CI: 0.0007,−0.0095), r2= 0.21, p = 0.03White: r2= 0.05, p = 0.27Strength of association not changed by including age inthe regression model.Braunstein et al.(1978)CaliforniaNRDesign: clinicalSubjects: adult male secondary Pb smelter(n = 12), mean age 38 yr, reference group,(n = 9), mean age 29 yrOutcome measures: serum EST, FSH, LH,TES, HCG-stimulated EST and TES, GnRHstimulated serum FSH and LHAnalysis: comparisons of outcome measuresbetween patients symptomatic for Pbpoisoning, Pb-exposed patients notsymptomatic, reference groupBlood Pb (μg/dL) mean (SD):Symptomatic (n = 9):Time of test: 38.7 (3.0)Highest: 88.2 (4.0)Asymptomatic (n = 4):Time of test: 29.0 (5.0)Highest: 80.0 (0.0)Reference: 16.1 (1.7)Statistically significant (p < 0.05) lower basal serumTES, higher TES response to HCG, and significantlyreduced LH response to GnRH in workers symptomaticfor Pb poisoning (including EDTA-provoked urinary Pb>500 μg/24 hr).Refowitz (1984)NRDesign: cross-sectional surveySubjects: secondary copper smelter workers(n = 58)Outcome measures: FT4, TT4Analysis: linear regressionBlood Pb (μg/dL) range:5–60No significant association between blood Pb andhormone levels:FT4:∀= 2.32,∃=−0.0067 (95% CI:−0.18, 0.0043)TT4:∀= NR,∃=−0.28 (95% CI:−0.059, 0.0002)No significant association when ratified by race (black,white)

# AX6-244Table AX6-9.6 (cont’d). Effects of Leadon the Endocrine System in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationCanadaAlexander et al. (1998,1996a)British Columbia1993Design: cross-sectionalSubjects: adult male primary smelter workers(n = 152), mean age 40 yrOutcome measures: serum FSH, LH, TESAnalysis: multivariate linear regressionBlood Pb (μg/dL) range(n = 81): 22.8 (5–58)Semen Pb (μg/dL) range:1.9 (0.1–17.6)No significant association betweencovariate-adjusted blood Pb andhormone levels (p∃0.5) or prevalence of abnormal levels.Significant association between covariate-adjusted increasingsemen Pb concentration and decreasing serum TES (∃=−1.57,p = 0.004).Covariates considered: age, smoking, alcohol, other metals in blood(arsenic, cadmium, copper, zinc), abstinence days prior to samplecollection, and sperm count.Schumacher et al.(1998)British Columbia1993Design: cross-sectionalSubjects: adult male smelter workers(n = 151) mean age 40 yr (SD 7.2)Outcome measures: serum FT4, TT4, TSHAnalysis: linear regression, ANOVABlood Pb (μg/dL) mean:24.1 (n = 151)<15 (n = 36)15–24 (n = 52)25–39 (n = 41)∃40 (n = 22)No significant effect of blood Pb(categorical) on covariate-adjustedor unadjusted FT4 (p = 0.68), TT4 (p = 0.13), TSH (p = 0.54). Nosignificant association of blood Pbwith prevalence of abnormalvalues of hormones. No significant association between 10-yr avgblood Pb and hormone levels orprevalence of abnormal values.Covariates considered: age and alcohol consumption.EuropeGennart et al. (1992)BelgiumNRDesign: cross sectional cohortSubjects: adult battery manufacture workers(n = 98), mean age 37.7 yr (SD 8.3, range 22–55); reference worker group (n = 85), meanage 38.8 yr (SD 8.7, range 22–55)Outcome measures: serum TT3, FT4, TT4,TSH, FSH, LHAnalysis: comparison of outcome measuresbetween Pb workers and reference groupBlood Pb (μg/dL) mean(SD, range):Pb: 51.0 (8.0, 40.0–75.0)Reference: 20.9 (11.1, 4.4–39.0)Urine Pb (μg/g creatinine)mean (range):Pb: 57.8 (1.95, 4.3–399)Reference: 9.75 (2.73,1.45–77.7)Mean hormone levels in Pb workers and reference group notdifferent (p = NR); no association between hormone levels andblood Pb or exposure duration quartile.

# AX6-245Table AX6-9.6 (cont’d). Effects of Leadon the Endocrine System in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationEurope(cont’d)Assennato et al. (1987)ItalyNRDesign: cross-sectionalSubjects: adult male battery manufactureworkers (n = 39), mean age 41 yr (SD 10);reference cement plant workers (n = 18), meanage 40 yr (SD 10)Outcome measures: serum FSH, LH, PRL,TES; urinary 17-ketosteroidsAnalysis: parametric comparison of outcomemeasures between Pb and reference groupsBlood Pb (μg/dL) mean(SD):Pb: 61 (20)Reference: 18 (5)Urinary Pb (μg/L) mean(SD):Pb: 79 (37)Reference: 18 (8)No significant association (p > 0.05) between blood Pb andhormone levels.Govoni et al. (1987)ItalyNRDesign: cross-sectionalSubjects: adult male pewter manufactureworkers (n = 78), mean age 35 yr (SD 19,range 19–52)Outcome measures: serum PRLAnalysis: parametric comparison of outcomemeasures between blood Pb and ZPP strataBlood Pb (μg/dL) mean(SD)/blood ZPP (μg/dL)mean (SD):A (n = 22):28.2 (7.1)/24.4 (8.7)B (n = 33):60/3 (19.3)/131 (107)C (n = 13):33.1 (6.7)/77.0 (42.2)D (n = 8):49.1 (4.2)/34.0 (4.8)Significantly (p < 0.02) higher serum PRL in high ZPP strata (B andC, compared to low ZPP strata A).Rodamilans et al.(1988)SpainNRDesign: cross-sectional cohortSubjects: adult male Pb smelter workers(n = 23), age range 21–44 yr; reference group(n = 20), age range 20–60 yrOutcome measures: serum FSH, LH, TES,FTES, SHBGAnalysis: comparison of outcome measuresbetween exposure duration strataBlood Pb (μg/dL) mean(SD)Pb <1 yr (n = 5): 66 (22)Pb 1–5 yr (n = 8): 73 (24)Pb >5 yr (n = 10): 76 (11)Reference (n = 20): 17.2(13)Serum TES (p = 0.01) and FTES (p= 0.001) significantly lower andSHBG significantly higher (p < 0.025) in >5-yr exposure groupcompared to reference group; serumLH was significantly (p < 0.01)higher in all exposure groups compared to reference group.

# AX6-246Table AX6-9.6 (cont’d). Effects of Leadon the Endocrine System in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationEurope(cont’d)Erfurth et al. (2001)SwedenNRDesign: cross-sectional cohortSubjects: adult male active secondary smelterworkers (n = 62), mean age 43 yr (range 21–78) reference worker group (n = 26), meanage 43 yr (range 23–66)Outcome measures: serum FT3, FT4, TSH,TES, SHBG; TRH-stimulated serum TSH;GnRH-stimulated serum FSH, LH, and PRLAnalysis: nonparametric comparison ofoutcome measures between Pb workers andreference group; multivariate linear regressionBlood Pb (μg/dL) median (range):Pb: 31.1 (8.3–93.2)Reference: 4.1 (0.8–6.2)Plasma Pb (μg/dL) median (range):Pb: 31.1 (8.3–93.2)Reference: 4.1 (0.8–6.2)Urine Pb (μg/g creatinine) median (range):Pb: 19.6 (3.1–80.6)Reference: 4.1 (2.4–7.3)Bone (finger) Pb (μg/g) median (range):Pb: 25 (−13 to 99)Reference: 2 (−21 to 14)Basal hormone levels in workers not different fromreference group (p∃0.05); age-adjusted basalhormone levels not associated with plasma Pb, bloodPb, urine Pb, or bone Pb. In an age-matched subsetof the cohorts (n = 9 Pb workers, n = 11 reference),median GnRH-stimulated serum FSH wassignificantly (p = 0.014) lower (77 IU/LΗhr) in Pbworkers than in reference group (162 IU/LΗhr).No association between stimulated TSH, LH, FSH orPRL and Pb measures.Gustafson et al. (1989)SwedenNRDesign: cross-sectional cohortSubjects: adult male secondary smelterworkers (n = 21) mean age 36.0 yr (SD 10.4);individually matched for age, sex, and workshift (n = 21)Outcome measures: serum FTES, TTES;FSH, LH, PRL, COR, TSH, TT3, TT4Analysis: nonparametric comparison ofoutcome measures between Pb workers andreference group, correlationBlood Pb (μg/dL) mean (SE):Pb: 39.4 (2.1)Reference: 5.0 (0.2)Significantly higher TT4 (p < 0.02) and lower serumFSH (p = 0.009) in Pb workers compared toreference group. When restricted to the age range<40 yr, Pb workers had significantly higher TT4(p = 0.01) and lower FSH (p = 0.03), LH (p = 0.04),and COR (p = 0.04), compared to the referencegroup.Campbell et al. (1985)UKNRDesign: cross-sectional cohortSubjects: adult male welders (n = 25);reference subjects (n = 8) (ages NR)Outcome measures: plasma ACE, AI, PRA,plasma ALDAnalysis: linear regression, nonlinear leastsquaresBlood Pb (μg/dL) mean(SD, range): 35.6(15.3, 8–62)Significant positive correlation between blood Pbconcentration and plasma ALD level (r = 0.53,p < 0.002), PRA (r =−0.76, p < 0.001), AI (r = 0.68,p < 0.002), and ACE (r = 0.74, p < 0.001).

# AX6-247Table AX6-9.6 (cont’d). Effects of Leadon the Endocrine System in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationEurope(cont’d)Chalkley et al. (1998)UK1979–1984Design: cross-sectionalSubjects: adult male primary metal(cadmium, Pb, zinc) workers (n = 19), agesNROutcome measures:blood calcium, serum 25-OH-D, 1,25-OH-D, 24,25-OH-DAnalysis: comparison of outcome measures(ANOVA) in group stratified by blood Pb andurinary cadmiumBlood Pb (μg/dL) mean(SD, range): 47 (21–76)After stratification by blood Pband urinary cadmium, serum 1,25-OH-D levels in strata were significantly different (p = 0.006), withhigher mean values in high blood Pb (>40 μg/dL)/high bloodcadmium (>0.9 μg/L)/high urinecadmium >3.1 μg/L) stratumcompared to low blood Pb (<40 μg/dL)/high blood cadmium(>0.9 μg/L)/high urine cadmium >3.1 μg/L) stratum. Serum 24,25-OH-D levels decreased with increasing urinary cadmium (p = NR)Mason et al. (1990)UKNRDesign: cross-sectionalSubjects: adult male Pb workers (n = 63), agerange 21–63 yr; reference male subjects(n = 75), age range 22–64 yrOutcome measures: serum calciumphosphate, PTH, 1,25-OH-DAnalysis: comparison of al outcome measuresbetween Pb workers and reference group,multivariate regressionBlood Pb (μg/dL) range:Pb (15–94)Reference: NRTibia Pb (μg/g)Pb: 0–93Reference: NRSignificantly higher (p < 0.025) prevalence of elevated 1,25-OH-D(>2 SD of reference mean) in Pb workers (8/63, 13%) compared toreference group (1/75, 1.3%). Serum levels of 1,25-OH-Dsignificantly (p < 0.05) higher in Pb workers compared to referencegroup.After stratification of Pb workersinto exposure categories (high:blood Pb∃40 μg/dL and bone Pb∃40 μg/g, low: blood Pb#40 μg/dL and bone Pb#40 μg/g), serum 1,25-OH-D levels weresignificantly (p < 0.01) higher in the high Pb group.Increasing blood Pb was significantly (p = NR) associated withincreasing 1,25-OH-D levels (r2= 0.206; with age and bone Pbincluded, r2= 0.218). After excluding12 subjects whose blood Pbconcentrations >60 μg/dL, r2= 0.162 (p = 0.26).McGregor and Mason,(1990)UKNRDesign: cross-sectional cohortSubjects: adult male Pb workers (n = 90),mean age (31.5 yr (SD 11.9); referenceworkers (n = 86), mean age 40.6 yr (SD 11.8)Outcome measures: serum FSH, LH, TES,SHBGAnalysis: comparison of outcome meansbetween Pb workers and reference groups,multivariate regression, correlationBlood Pb (μg/dL) range:Pb: 17–77Reference: <12Age-adjusted serum FSH was significantly (p = 0.004) higher in Pbworkers compared to reference group.Increasing serum FSH significantly(p = NR) associated with bloodPb and age. Increasing serum LH significantly associated withincreasing exposure duration (not blood Pb or age).No significant association between serum TES or SHBG and bloodPb or exposure duration.No significant difference in prevalence of abnormal hormone levelsbetween groups.

# AX6-248Table AX6-9.6 (cont’d). Effects of Leadon the Endocrine System in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationLatin AmericaL∴pez et al. (2000)ArgentinaNRDesign: cross sectionalSubjects: adult male battery manufactureworkers (n = 75), age range 21–56 yr;reference group (n = 62), age NROutcome measures: serum TT3, FT4, TT4,TSHAnalysis: comparison of outcome measuresbetween Pb workers and reference group,correlationBlood Pb (μg/dL) mean(range):Pb: 50.9 (23.3, 8–98)Reference: 19.1 (7.1, 4–39)Significantly higher serum FT4 (p < 0.01) and TT4 (p < 0.05) in Pbworkers compared to reference group. Significant positivecorrelation between blood Pb and serum TT3 (p < 0.05), FT4(p < 0.01), TT4 (p < 0.05), and TSH (p < 0.05), for blood Pb range8–50 μg/dL; and for TSH (p < 0.05) for blood Pb range 8–26 μg/dL.Roses et al. (1989)BrazilNRDesign: adult male Pb workers (n = 70), agerange 20–53 yr; reference group (n = 58), agerange 25–37 yr.Outcome measures: serum PRLAnalysis: comparison of outcome measurebetween Pb workers and reference group,linear regressionBlood Pb (μg/dL) range:Pb: 9–86Reference: 8–28Serum RL levels in Pb workers and reference group notsignificantly different (p = NR).Correlation between serum PRLand blood Pb (r = 0.57, p = NR).AsiaDursun and Tutus(1999)TurkeyNRDesign: cross-sectionalSubjects: adult metal powder manufactureworkers (n = 27) mean age 41.1 yr (SD 5.45,range 25–50); reference group (n = 30), meanage 42 yr (SD 3.42, range 28–49)Outcome measures: serum FT4, TT4, FT3,TT3, TSHAnalysis: parametric comparison of outcomemeasures between Pband reference groups,simple and multivariate linear regressionBlood Pb (μg/dL) mean(range):Pb: 17.1 (9.0, 6–36)Reference: 2.4 (0.1, 1–4)Significantly (p < 0.0001) higher mean TT4, FT4, and FT3 in Pbworkers compared to reference group.Significant association between TT4, age (∃= 0.23, p < 0.006), andexposure duration (∃=−0.20, p > 0.01), but not blood Pb (∃= 0.00,NR) in linear regression model that included age, blood Pb, andexposure duration (∀= 2.76, r2= 0.3, p = 0.03).

# AX6-249Table AX6-9.6 (cont’d). Effects of Leadon the Endocrine System in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationAsia(cont’d)Kristal-Boneh et al.(1998)IsraelNRDesign: cross-sectional cohortSubjects: adult male batterymanufacture/recycling workers (n = 56), meanage 43.4 yr (SD 11.2); reference workers(n = 90), mean age 41.5 yr (SD 9.3)Outcome measures: serum calcium,magnesium, phosphorus, PTH, 25-OH-D,1,25-OH-DAnalysis: parametric comparison of outcomemeasures between Pb workers and referencegroup, multivariate linear regressionBlood Pb (μg/dL) mean(SD, range):Pb: 42.6 (14.5, 20–77)Reference: 4.5 (2.6, 1.4–19)Serum 1,25-OH-D (p = 0.0001) and PTH (p = 0.042) weresignificantly higher in Pb workers compared to reference groupIncreasing blood Pb concentration (ln-transformed) wassignificantly associated with covariate-adjusted increasing serumPTH and 1,25-OH-D levels:PTH:∃= 4.8 (95% CI: 0.8, 8.8), r2= 0.121,25-OH-D:∃= 4.8 (95% CI: 2.7, 6.9), r2= 0.10Occupational Pb exposure (yes) significantly associated withincreasing PTH and 1,25-OH-D levels.Covariates retained: age, alcoholconsumption, smoking; calcium,magnesium, and calorie intake:PTH:∃= 7.81 (95% CI: 3.7, 11.5)1,25-OH-D:∃= 12.3 (95% CI: 3.84, 20.8)Horiguchi et al. (1987)JapanNRDesign: cross-sectionalSubjects: adult secondary Pb refinery (n = 60,8 females), mean age 49 yr (range 15–69)Outcome measures: serum TT3, TT4, TSHAnalysis: comparison of outcome measures(method NR), between job categories,correlationBlood Pb (μg/dL) mean(SD):Male: 31.9 (20.4)Female: 13.5 (9.5)Urine Pb (μg/L) mean (SD):Male: 59.3 (76.3)Female: 26.0 (19.7)No significant differences (p = NR) between hormone levels in jobPb categories: mean blood Pb(μg/dL, SD): 17.9 (10.7), 25.6(15.4), 49.9 (18.7). No significantcorrelations (p = NR) betweenhormone levels and blood or urine Pb levels.Ng et al. (1991)ChinaNRDesign: cross-sectional cohortSubjects: adult male battery manufactureworkers (n = 122), mean age 32.6 (SD 8,2,range 17–54); reference group (n = 49), meanage 43.4 yr (SD 13.4, range 18–74)Outcome measures: serum FSH, LH, PRL,TESAnalysis: multivariate linear regressionANCOVABlood Pb (μg/dL) mean(SD, range):Pb: 35.2 (13.2, 9.6–77.4)Reference: 8.3 (2.8, 2.6–14.8)When cohorts were stratified by age serum FSH and LH weresignificantly (p < 0.02) higher in Pb workers <40 yrs of agecompared to corresponding age strata of the reference group; serumTES was significantly (p < 0.01) lower in Pb workers∃40 yr of age.Covariate-adjusted serum TES weresignificantly lower (p < 0.01)in Pb workers in the∃10-yr exposure duration category, comparedto the reference group. Covariate-adjusted serum FSH and LH weresignificantly higher (p < 0.01) in Pb workers in the <10-yr exposureduration category, compared to the reference group.Covariates: age and tobacco smoking.

# AX6-250Table AX6-9.6 (cont’d). Effects of Leadon the Endocrine System in AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationAsia(cont’d)Zheng et al. (2001)ChinaNRDesign: retrospective cross-sectionalSubjects: adult hospital patients (n = 82, 32females) mean age 49.6 yr (SD 18.7)Outcome measures: serum and CSF TTR,TT4Analysis: simple and multivariate linearregressionBlood Pb (μg/dL) mean(SD):All: 14.9 (8.3)Female: 14.2 (8.76)Male: 15.4 (8.07)No significant association between blood Pb and serum TTR(r =−0.114, p = 0.307), TT4 (r =−0.160, p = 0.152).Significant association between age-adjusted CSF Pb and CSF TTR(r =−030, p = 0.023).No significant association between CSF Pb and CSF TT4(r =−0.22, p = 0.090).Singh et al. (2000)IndiaNRDesign: cross-sectional cohortSubjects: adult malepetrol pump attendants(n = 58), mean age 31.7 yr (SD 10.6);reference group (n = 35), mean age 28.9 yr(SD 4.20)Outcome measures: serum TT3, TT4, TSHAnalysis: parametric comparison of outcomemeasures between Pb workers and referencegroup, stratified by blood Pb or exposuredurationBlood Pb (μg/dL) mean(SD):Pb: 51.6 (9.3)Reference: 9.5 (8.7)Serum TSH significantlyhigher (p < 0.01) in Pb workers comparedto reference group, significantlyhigher in high blood Pb category(#70 μg/dL, mean 54.5 μg/dL) compared to low worker group#41 μg/dL, mean 31.3 μg/dL). Serum TSH significantly higher inPb workers who were exposed for#60 mo, compared to workersexposed for >60 mo.AfricaTuppurainen et al.(1988)Kenya1984Design: cross-sectionalSubjects: adult male battery manufactureworkers (n = 176), mean age 34.1 yr(SD 8.1, range 21–54)Outcome measures: serum TT3, FT4,TT4, TSHAnalysis: multivariate linear regressionand correlationBlood Pb (μg/dL) mean(SD, range):55.9 (23.8, 14.5–133.6)Increasing exposure duration significantly associated withdecreasing FT4 (r2= 0.071, p = 0.001) and TT4 (r2= 0.059,p = 0.021); regression not improved by including age or blood Pb.Strength of association greater whenrestricted to workers who hadan exposure duration >7.6 yrs: FT4: r2= 0.33, p < 0.002; TT4:r2= 0.21, p < 0.001.No significant association between blood Pb and hormone levels.

# AX6-251Table AX6-9.7. Effects of Lead on theHepatic System in Children and AdultsReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationChildrenUnited StatesSaenger et al. (1984)New YorkNRDesign: clinical casesSubjects: children (n = 26) ages 2–9 yr; age-matched reference group (n = NR)Outcome measures: urinary cortisol and 6∃-OH-cortisol (CYP3A metabolite of cortisol)Analysis: comparison of outcome measurebetween children whoqualified for EDTAtreatment (EDTA provocation >500 μg/24hr)Blood Pb (μg/dL) mean(SE, range):Chelated: 46 (2, 33–60)Not chelated:42 (3, 32–60)Urinary Pb (μg/24 hr) mean(SE, range), EDTA-provocation:Chelated: 991 (132, 602–2247)Not chelated: 298 (32,169–476)Significantly lower (~45% lower) urinary excretion of 6∃-OH-cortisol (p = 0.001) and urinary 6∃-OH-cortisol: cortisol ratio(p < 0.001) in children who qualifiedfor chelation than in childrenwho did not qualify and significantly lower than age-matchedreference group. Urinary 6∃-OH-cortisol: cortisol ratio wassignificantly correlated with blood Pb (r =−0.514, p < 0.001),urinary Pb, and EDTA provocation urinary Pb (r =−0.593,p < 0.001).AdultsAsiaAl-Neamy et al. (2001)United Arab Emirates1999Design: cross-sectional cohortSubjects: adult male (n = 100) workers (e.g.,gas pump attendants, garage workers,printing workers, construction workers),mean age 34.6 yr (SD 8.0); reference group(n = 100) matched with Pb workers for age,sex, nationality.Outcome measures: serum protein, albumin,ALT, AP, AST, BUN,(GT, LDHAnalysis: comparison of outcome measuresbetween Pb workers and reference groupBlood Pb (μg/dL) mean(SD): Pb: 77.5 (42.8)Reference: 19.8 (12.3)Significantly higher serum AP (p = 0.012) and LDH (p = 0.029) inPb workers compared to reference group (values within normalrange).

# AX6-252Table AX6-9.7 (cont’d). Effects of Lead onthe Hepatic System in Children and AdultsReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationAsia(cont’d)Hsiao et al. (2001)China1989–1999Design: longitudinalSubjects: adult battery manufacture workers(n = 30, 13 females), mean age 38.3 yrOutcome measures: serum ALTAnalysis: GEE for repeated measures(models: linear correlation, thresholdchange, synchronous change, lag change);logistic regressionBlood Pb (μg/dL) mean:1989: 60 (~25–100)1999: 30 (~10–60)No association between blood Pb and ALT.Odds ratios (95% CI):Synchronous change model: 1.25 (0.69, 2.25)Lag change: 1.76 (0.76, 4.07)Satarug et al. (2004)ThailandNRDesign: cross-sectionalSubjects: adults from general population(n = 118, 65 female), age range, 21–57 yrOutcome measures: coumarin-inducedurinary 7-OH-coumarin (marker forCYP2A6 activity)Analysis: multivariate linear regressionUrinary Pb (μg/gcreatinine) mean(SD, range):Males: 1.3 (1.8, 0.1–12)Females: 2.4 (1.1, 0.6–6.8)Serum Pb (μg/L) mean(SD, range):Males: 4.2 (5.4, 1–28)Females: 3.0 (2.2, 1–12)Significant association between increasing urinary Pb and decreasingcovariate-adjusted urinary 7-OH-coumarin (∃=−0.29, p = 0.003) inmales, but not in females. Covariates retained: age and zincexcretion. Significant association in opposite direction betweenurinary cadmium and urinary 7-OH-coumarin (∃= 0.38, p = 0.006).

# AX6-253Table AX6-9.8. Effects of Lead on the Gastrointestinal SystemReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationCanadaHolness and Nethercott(1988)Ontario1982–1984Design: longitudinalSubjects: adult male demolition workers(n = 119), age NROutcome measures: prevalence of symptomsAnalysis: comparison of prevalence ofsymptoms (questionnaire) stratified by jobphase or blood PbBlood Pb (μg/dL) mean(range):Phase 1: 59 (15–99)Phase 2: 30Phase 3: 19Phase 4: 17Prevalence of reporting of symptoms of abdominal cramps orconstipation increased with increasing blood Pb concentration(p < 0.05):<50 μg/dL: 8%, 6%50–70 μg/dL: 37%, 42%>70 μg/dL: 77%, 62%CaribbeanMatte et al. (1989)Jamaica1987Design: surveySubjects: battery manufacture/repairworkers (n = 63), mean age ~30 yr(range 11–47)Outcome measures: prevalence of symptomsAnalysis: comparison of GI symptoms(questionnaire) between blood Pb strataBlood Pb (μg/dL)geometric mean site range:40–64Blood Pb distribution:>60: 60%<60: 40%When stratified by blood Pb, <60 μg/dL (low) or∃60 μg/dL (high),prevalence ratio (high/low) wasnot significant forabdominal pain(1.5, [95% CI: 0.5, 4.6]), or for any other Pb symptom (e.g. muscleweakness).AsiaBercovitz and Laufer(1991)IsraelNRDesign: cross-sectionalSubjects: health individuals (n = 12), pepticulcer patients (n = 11), and individuals withheart disease (n = 11) with environmentalexposureAnalysis: one-way ANOVA used tocompare tooth Pb concentrations in the threegroupsTooth Pb (:g/g dry dentine)mean (SE):Healthy: 25.62 (10.15)Peptic ulcer: 75.02 (8.15)Heart disease: 20.30 (2.70)Tooth Pb levels in patients with gastrointestinal ulcers (n = 11), weresignificantly higher than that in healthy subjects (p = 0.001)). Ten ofthe 11 peptic ulcer patients had a higher Pb level than the healthsubjects. In these 10 patients, increased severity of the ulcer andlongevity of suffering was associated with increased tooth Pb levels.There was no significant differencebetween the tooth Pb levels inthe healthy subjects and inthe heart disease patients.

# AX6-254Table AX6-9.8 (cont’d). Effects of Lead on the Gastrointestinal SystemReference, StudyLocation, and Period Study DescriptionPb Measurement Findings, InterpretationAsia(cont’d)Lee et al. (2000)KoreaNRDesign: cross-sectional cohortSubjects: adult male Pb workers (n = 95;secondary smelter,PVC-stabilizermanufacture, battery manufacture); mean age42.8 yr (SD 9.3, range 19–64); referencegroup (n = 13), mean age 35.1 yr (SD 9.9,range 22–54)Outcome measures: prevalence of GIsymptoms (self-administered questionnaire)Analysis: multivariate logistic regressionBlood Pb (μg/dL) mean(SD, range):Pb: 44.6 (12.6, 21.4–78.4)Reference:5.9 (1.2, 4.0–7.2)Covariate-adjusted OR for GI symptoms (loss of appetite,constipation or diarrhea, abdominalpain) in workers (referents notincluded in model) were not significant:Blood Pb (45.7 μg/dL vs. <45.7 μg/dL): OR = 1.8 (95%CI: 0.7, 4.5)DMSA-provoked urinary Pb (>260.5 vs. <260.5 μg): OR = 1.1(95% CI: 0.4, 2.5)OR for neuromuscular symptoms were significantly associated withDMSA-provoked Pb (OR = 7.8 [95% CI: 2.8, 24.5]), but not withblood Pb.Covariates retained: age,tobacco smoking, and alcoholconsumption.AfricaAwad el Karim et al.(1986)SudanNRDesign: cross-sectional cohortSubjects: adult male battery manufactureworkers (n = 92), mean age 31.1 yr (SD 8.2);reference group (n = 40), mean age 33.7 yr(SD 9.7)Outcome measures: clinical evaluationAnalysis: comparison of prevalence ofsymptoms of Pb poisoning between Pbworkers and reference groupBlood Pb distribution forPb workers>80: 23%40–80: 72%<40: 5%Blood Pb (μg/dL) mean(SD, range):Pb: 55–81 (mean range forvarious jobs), range 39–107Reference: 21 (8.5, 7.4–33.1)Prevalences of abdominal colic (pain) and constipation were 41.3%and 41.4 % in Pb workers and 7.5%and 10%, respectively, in thereference group.

# AX6-255Table AX6-9.9. Effects of Lead on Bone and Teeth in Children and AdultsReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationChildrenUnited StatesMoss et al. (1999)U.S.1988–1994Design: cross-sectional national survey(NHANES III)Subjects: general population (n = 24,901),ages 2–5 yr (n = 3,547), 6–11 yr (n = 2,894),∃12 yr (18,460)Outcome measures: number of caries (dfs,DFS, DMFS)Analysis: multivariate linear regression andlogistic regressionBlood Pb (:g/dL) geometricmean (SE):2–5 yr: 2.90 (0.12)6–11 yr: 2.07 (0.08)∃12 yr: 2.49 (0.06)Increasing blood Pb concentration (log-transformed) significantlyassociated with covariate adjusted increases in dfs:2–5 yr:∃= 1.78 (SE 0.59), p = 0.0046–11 yr:∃= 1.42 (SE 0.51), p = 0.007Increases in DFS:6–11 yr:∃= 0.48 (SE 0.22), p = 0.03∃12 yr:∃= 2.50 (SE 0.69), p < 0.001Increases in DMFS:∃12 yr:∃= 5.48 (SE 1.44), p = 0.01Odds ratio (OR) for caries (∃1 DMFS, ages 5–17 yr) and populationattributable risk (PAR) in association with 2nd or 3rd blood Pbtertiles, compared to 1st tertile were:1st tertile (#1.66:g/dL)2nd tertile (1.66–3.52:g/dL): OR = 1.36 (95% CI: 1.01, 2.83);PAR = 9.6%3rd tertile (>3.52:g/dL): OR = 1.66 (95% CI: 1.12, 2.48);PAR = 13.5%For an increase of blood Pb of 5:g/dL, OR = 1.8 (95% CI: 1.3, 2.5)Covariates retained were age, gender, race/ethnicity, poverty incomeratio, exposure to cigarette smoke, geographic region, educationallevel of head of household, carbohydrate and calcium intakes, anddental visits.

# AX6-256Table AX6-9.9 (cont’d). Effects of Leadon Bone and Teeth in Children and AdultsReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationUnited States(cont’d)Schwartz et al. (1986)U.S.1976–1980Design: cross-sectional national survey(NHANES II)Subjects: ages <7 yr (n = 2,695)Outcome measures: variables of stature,including height, weight, and chestcircumferenceAnalysis: multivariate weighted linearregressionBlood Pb (:g/dL) range:5-35Blood Pb levels were a statisticallysignificant predictor of children’sheight (p < 0.0001), weight (p< 0.001), and chest circumference(p < 0.026), after controlling for age in mos, race, sex, and nutrition.Height:∃=−0.119 (SE 0.0005)Weight:∃=−1.0217 (SE 0.08) for log-transformed blood PbChest circumference:∃=−0.6476 (SE 0.077) for log-transformedblood PbThere are several explanations for the inverse correlation betweenblood Pb and growth in children.First, blood Pb level may be acomposite factor for genetic, ethnic, nutritional, environmental, andsociocultural factors. Second, nutritional deficits that retard growthalso enhance Pb absorption. Finally, there may be a direct effect oflow level Pb on growth in children.Gemmel et al. (2002)Boston/Cambridge, MANRDesign: cross-sectionalSubjects: children (n = 543), ages 6–10 yrOutcome measures: number of caries (dfs,DFS)Analysis: multivariate linear regressionBlood Pb (:g/dL) mean(SD, max):Urban (n = 290): 2.9 (2.0,13)Rural (n = 253): 1.7 (1.0, 7)Increasing blood Pb (ln-transformed) was significantly associatedwith covariate-adjusted number of caries (dfs + DFS) (lntransformed) in the urban (∃= 0.22 [SE 0.08], p = 0.005) group, butnot in the rural group (∃=−0.15 [SE 0.09], p = 0.09). When dfsnumbers were stratified by permanent or deciduous teeth, the bloodPb association in the urban group was significant for deciduousteeth.(∃= 0.28, SE 0.09, p = 0.002), but not for permanent teeth (∃= 0.02,SE 0.07, p = 0.8).Covariates retained: age, sex, ethnicity, family income, education offemale guardian, maternal smoking,frequency of tooth brushing,firmness of toothbrush bristles,and frequency of chewing gum.Campbell et al. (2000)New York1995–1997Design: retrospective cohortSubjects: children (n = 154), ages 6.9–12 yrOutcome measures: prevalence of caries(dfs, DMFS)Analysis: multivariate logistic regressionBlood Pb (:g/dL) mean(range): 10.7 (18.0–36.8)(measured at ages 18 and37 mo)Covariate-adjusted odds ratios forcaries in association with bloodPb <10 or∃10:g/dL, were:permanent teeth (DMFS): OR =0.95 (95% CI: 0.43, 2.09)deciduous teeth (dfs): OR = 1.77 (95% CI: 0.97, 3.24)Covariates retained: age, gradein school, number of tooth surfacesat risk. Other covariates explored, that had no effect on strength ofassociation with blood Pb were: sex, ethnicity, and oral hygienescore.

# AX6-257Table AX6-9.9 (cont’d). Effects of Leadon Bone and Teeth in Children and AdultsReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationAdultsUnited StatesDye et al. (2002)U.S.1988–1994Design: cross-sectional national survey(NHANES III)Subjects: adults in general population(n = 10,033; 5,255 females), ages 20–69 yrOutcome measures: symptoms ofperiodontal bone loss(attachment loss,periodontal pocket depth)Analysis: multivariate linear regressionBlood Pb (:g/dL) geometricmean (SE, range):2.5 (0.08) (2.36% > 10)Increasing blood Pb (log-transformed) was significantly associatedwith increasing prevalence of covariate-adjusted dental furcation(∃= 0.13 [SE 0.05], p = 0.005). Covariates retained: age, sex,race/ethnicity, education, smoking, and age of home. Smokingstatus interaction was significant when included in the model as aninteraction term (∃= 0.10 [SE 0.05], p = 0.034). When stratified bysmoking status, association betweendental furcation and blood Pbwas significant for current smokers (∃= 0.21 [SE 0.07], p = 0.004)and former smokers (∃= 0.17 [SE 0.07], p = 0.015), but not fornonsmokers (∃=−0.02 [SE 0.07], p = 0.747).EuropeTvinnereim et al.(2000)Norway1990–1994Design: cross-sectionalSubjects: 1,271 teeth samples collected bydentists in all 19 counties in NorwayAnalysis: Student’s t-test comparing metalconcentrations in teeth with caries, roots, andin different tooth groupsTooth Pb (:g/g tooth)geometric mean (SD,range):1.16 (1.72, 0.12–18.76)Also examined mercury, cadmium, and zinc. All tooth groups hadhigher Pb concentrations in cariousthan in non-carious teeth. Thegeometric mean Pb concentration in carious teeth was 1.36:g/gcompared to 1.10:g/g (p = 0.001).

# AX6-258Table AX6-9.10. Effects of Lead on Ocular Health in Children and AdultsReference, StudyLocation, and PeriodStudy Description Pb Measurement Findings, InterpretationChildrenLatin AmericaRothenberg et al.(2002b)Mexico1987–1997Design = longitudinal (subset of prospective)Subjects: children (n = 45, 24 female), ages7–10 yrOutcome measures: ERGAnalysis: comparison of outcome measuresbetween blood Pbtertiles (ANOVA forrepeated measures)Blood Pb (:g/dL) median(range) at 85–124 mo:1st tertile: 4.0 (2.0–4.5)2nd tertile: 6.0 (5.0–6.5)3rd tertile: 7.5 (7.0–16.0)Blood Pb (:g/dL) median(range), maternal at 12 wkof gestation:1st tertile: 4.0 (2.0–5.5)2nd tertile: 8.5 (6.0–10.0)3rd tertile: 14.0 (10.5–32.5)Significant association between increasing maternal blood Pb at12 wk of gestation and increasing ERG a-wave (p = 0.025) and b-wave amplitude (p = 0.007), with significant increases in a-wave inthe 2nd blood Pb tertile (6.0–10.0:g/dL), and a-wave and b-wave inthe 3rd blood Pb tertile (10.5–32.5:g/dL), compared to the 1st bloodPb tertile.AdultsUnited StatesSchaumberg et al.(2004)Massachusetts1991–2002Design = longitudinal (subset of NormativeAging Study)Subjects: adult male (n = 642), mean age69 yr (range 60–93)Outcome measures: cataract diagnosisAnalysis: multivariate logistic regression,odds ratio (vs. 1st quintile)Blood Pb (:g/dL) median(range):5 (0–35)Bone Pb (:g/g) median(range):Patella : 29 (0–165)Tibia: 20 (0–126)Significant covariate adjusted odds ratio (OR) for cataracts in 5thtibia bone Pb quintile (31.0–125:g/g), OR = 3.19 (95% CI: 1.48,6.90), p = 0.01. OR for cataractswere not significantly associatedwith patella bone Pb (5th quintile: 43.0–165:g/g), OR = 1.88 (95%CI: 0.88, 4.02), or blood Pb (5th quintile: 8.17–35.0:g/dL), OR =0.89 (95% CI: 0.46, 1.72).Covariates retained: age, smoking,history of diabetes, daily intakeof vitamin C, vitamin E, and carotenoids.

# AX6-259Table AX6-9.10 (cont’d). Effects of Lead on Ocular Health in Children and AdultsReference, StudyLocation, and PeriodStudy DescriptionPb MeasurementFindings, InterpretationAdultsEuropeCavalleri et al. (1982)ItalyNRDesign = cross-sectional cohortSubjects: adult male vinyl chloride pipemanufacture workers, exposed to Pb stearate(n = 35), mean age 45 yr (SD 14, range 21–59); reference group (n = 35) matched forage, smoking, and alcohol consumption.Outcome measures: visual fieldAnalysis: comparison of outcome measuresbetween Pb workers and reference groupBlood Pb (:g/dL) mean(SD, range):Pb: 46 (14, 21–82)Reference: 23 (4, 21–37)Urine Pb (:g/L) mean (SD,range):Pb: 71 (18, 44–118)Reference: 30 (5, 21–42)Visual sensitivity was significantly (p = 0.003) lower in Pb workerscompared to the reference group; however, visual sensitivity indexwas not significantly associated with blood or urine Pb. Mesopicfield scotoma prevalence was 10 of 35 (28%) in Pb workers and 0%in the reference group.

# AX6-260 

# REFERENCES

Abbate, C.; Buceti, R.; Munaò, F.; Giorgianni, C.; Ferrer i, G. (1995) Neurotoxicity induced by Pb levels: an electrophysiological study. Int. Arch. Occup. Environ. Health 66: 389-392.

Adachi, J. D.; Arlen, D.; We bber, C. E.; Chettle, D. R.; Beaumont, L. F.; Gordon, C. L. (1998) Is there any
association between the presence of bone disease and cumulative exposur e to Pb? Calcif. Tissue Int.

63: 429-432. Ades, A. E.; Kazantzis, G. (1988) Lung cancer in a non-ferrous smelter: the role of cadmium. Br. J. Ind. Med.

45: 435-442. Agency for Toxic Substances and Diseas e Registry. (1993) Toxicological profile for cadmium. Atlanta, GA: U.S.
Department of Health & Human Services, Public Health Service; report no. ATSDR/TP-92/06. Available from: NTIS, Springfield, VA; PB93-182418.
Agency for Toxic Substances and Disease Registry. (199 9) Toxicological profile for Pb. Atlanta, GA: U.S.
Department of Health and Human Services, Public Health Service. Agency for Toxic Substances and Diseas e Registry. (2005) Toxicological profile for Pb [draft]. Atlanta, GA: U.S.
Department of Health and Human Services , Public Health Service. Available:
http://www.atsdr.cdc.gov/toxprofile s/tp13.pdf [5 May, 2006]. Ǻ kesson, A.; Lundh, T.; Vahter, M.; Bjelle rup, P.; Lidfeldt, J.; Nerbrand, C.; Go ran, S.; Strömberg, U.; Skerfving,
S. (2005) Tubular and glomerular kidney effects in Swedish women with low environmental cadmium
exposure. Environ. Health Perspect. 113: 1627-1631. Ǻ kesson, A. (2006) Personal communication [from Agneta Ǻ kesson to Virginia Weaver with attached
GFR plots]. April 12.
Al-Ashban, R. M.; Aslam, M.; Shah, A. H. (2004) Kohl (surma): a toxic traditional eye cosmetic study in Saudi

Arabia. Public Health 118: 292-298.
Al-Hakkak, Z. S.; Hamamy, H. A.; Murad, A. M.; Hussain, A. F. (1986) Chromosome ab errations in workers at a
storage battery plant in Iraq. Mutat. Res. 171: 53-60. Al-Neamy, F. R.; Almehdi, A. M.; Alwash, R.; Pasha, M. A. H.; Ibrahim, A.; Bener, A. (2001) Occupational Pb
exposure and amino acid profiles and liver function te sts in industrial worker s. Int. J. Environ.

Health Res. 11: 181-188. Al-Saleh, I.; Nester, M.; DeVol, E.; Shinwari, N.; Munchari, L.; Al-Shahria, S. (2001) Relationships between blood
Pb concentrations, intelligence, and academic achievement of Saudi Arabian schoolgirls. Int. J. Hyg.

Environ. Health 204: 165-174.

Alessio, L.; Bertazzi, P. A.; Monelli, O.; Toffoletto, F. (1976) Free erythrocyte protoporphyr in as an indicator of the
biological effect of Pb in adult males. III. Behavior of free erythrocyte protoporphyrin in workers with past Pb exposure. Int. Arch. Occup. Environ. Health 38: 77-86.

Alessio, L.; Castoldi, M. R.; Buratti, M.; Maroni, M.; Bertazzi, P. A. (1977) Behaviour of some indicators of
biological effect in female Pb workers. Int. Arch. Occup. Environ. Health 40: 283-292. Alexander, B. H.; Checkoway, H.; Van Netten, C.; Muller, C. H.; Ewers, T. G.; Kaufman, J. D.; Mueller, B. A.;
Vaughan, T. L.; Faustman, E. M. (1996a) Semen quality of men employed at a Pb smelter. Occup. Environ.

Med. 53: 411-416. Alexander, B. H.; Checkoway, H.; Van Netten, C.; Kaufman, J. D.; Vaughan, T. L.; Mueller, B. A.; Faustman, E. M.
(1996b) Paternal occupational Pb exposure and pregnancy outcome. Int. J. Occup. Environ. Health 2: 280-

285. Alexander, B. H.; Checkoway, H.; Faustman, E. M.; Van Ne tten C.; Muller, C. H.; Ewers, T. G. (1998) Contrasting

associations of blood and semen Pb concentrations with semen quality among Pb smelter workers. Am. J.

Ind. Med. 34: 464-469. Alfvén, T.; Järup, L.; Elinder, C.-G. (2002) Cadmium and Pb in blood in relation to low bone mineral density and
tubular proteinuria. Environ. Health Perspect. 110: 699-702.
Alomran, A. H.; Shleamoon, M. N. (1988) The influence of chronic Pb exposure on lymphocyte proliferative response and immunoglobulin levels in storage battery workers. J. BioI. Sci. Res. 19: 575-585.
American Educational Research Association, American Psychological Association, National Council on
Measurement in Education. (1999) Standards for educational and psychological testing. Washington, DC: American Psychological Association.
American Thoracic Society. (2000) What constitutes an advers e health effect of air pollu tion? Am. J. Respir. Crit.

Care Med. 161: 665-673.

# AX6-261 Anetor, J. I.; Adeniyi, F. A. A. (1998) Decreased immune status in Nigerian workers occupationally exposed to Pb.

Afr. J. Med. Med. Sci. 28: 169-172. Angell, N. F.; Lavery, J. P. (1982) The relationship of blood levels to obstetric outcome. Am. J. Obstet. Gynecol.

142: 40-46. Angle, C. B.; Kuntzelman, D. R. (1989) Increased erythrocyte protoporphyrins and blood Pb; a pilot study of childhood growth patterns. J. Toxicol. Environ. Health 26: 149-156.
Angle, C. R.; McIntire, M. S. (1978) Low level Pb and in hibition of erythrocyte pyrimidine nucleotidase. Environ.

Res. 17: 296-302. Angle, C. R.; McIntire, M. S.; Swanson, M. S.; Stohs, S. J. (1982) Erythrocyte nucleotides in children - increased
blood Pb and cytidine triphosphate. Pediatr. Res. 16: 331-334.
Annesi-Maesano, I.; Pollitt, R.; King, G.; Bousquet , J.; Hellier, G.; Sahuquillo, J.; Huel, G. (2003) In utero exposure to Pb and cord blood total IgE. Is there a connection? Allergy 58: 589-594.

Annest, J. L.; Pirkle, J. L.; Makuc, D.; Neese, J. W.; Bayse, D. D.; Kovar, M. G. (1983) Chronological trend in blood Pb levels between 1976 and 1980. N. Engl. J. Med. 308: 1373-1377.
Anttila, A.; Heikkila, P.; Pukkala, E.; Nykyri, E.; Kauppinen, T.; Hernberg, S; Hemminki, K. (1995) Excess lung
cancer among workers exposed to Pb. Scand. J. Work Environ. Health. 21: 460-469. Anttila, A.; Heikkila, P.; Nykyri, E.; Kauppinen, T.; Pukkala, E.; Hernberg, S.; Hemminki, K. (1996) Risk of
nervous system cancer among workers exposed to Pb. J. Occup. Environ. Med. 38: 131-136.
Apostoli, P.; Maranelli, G.; Dei Cas, L.; Micciolo, R. (1990) Blood Pb and blood pressure: a cross sectional study in a general population group. Cardiologia 35: 597-603.
Apostoli, P.; Kiss, P.; Porru, S.; Bonde, J. P.; Va nhoorne, M.; the ASCLEPIOS study group. (1998) Male
reproductive toxicity of Pb in animals and humans. Occup. Environ. Med. 55: 364-374. Apostoli, P.; Bellini, A.; Porru, S.; Bisa nti, L. (2000) The effect of Pb on male fertility: a time to pregnancy (TTP)
study. Am. J. Ind. Med. 38: 310-315.

Armon, C.; Kurland, L. T.; Daube, J. R.; Obrien, P. C. (1991) Epidemiologic correlates of sporadic amyotrophic lateral sclerosis. Neurology 41: 1077-1084.
Arnvig, E.; Grandjean, P.; Beckmann, J. (1980) Neurotoxic effects of heavy Pb exposure determined with
psychological tests. Toxicol. Lett. 5: 399-404.

Aro, A. C. A.; Todd, A. C.; Amarasiriwardena, C.; Hu, H. (1994) Improvemen ts in the calibration of 109 

# Cd K x-ray
fluorescence systems for measuring bone Pb in vivo . Phys. Med. Biol. 39: 2263-2271.

Assennato, G.; Paci, C.; Baser, M. E.; Molinini, R.; Cand ela, R. G.; Altamura, B. M.; Giorgino, R. (1986) Sperm count suppression without endocrine dysfunction in Pb-exposed men. Arch. Environ. Health 41: 387-390.

Assennato, G.; Baser, M.; Molinini, R.; Candela, R. G.; Altamura, B. M.; Gi orgino, R.; Abbaticchio, G.; Paci, C. (1987) Sperm count suppression without endocrine dysfunction in Pb-exposed men. Arch. Environ. Health

42: 124-127. Astrin, K. H.; Bishop, D. F.; Wetmur, J. G.; Kaul, B.; Davidow, B.; Desnick, R. J. (1987) δ -aminolevulinic acid dehydratase isozymes and Pb toxicity. In: Silbergeld, E. K.; Fowler, B. A., eds. Mechanisms of chemicalinduced porphyrinopathies. New York, NY: New York Academy of Sciences; pp. 23-29. (Annals of the
New Yord Academy of Sciences: v. 514). Auger, J.; Kunstmann, J. M.; Czyglik, F.; Jouannet, P. (1995) Decline in semen quality among fertile men in Paris
during the past 20 yrs. N. Engl. J. Med. 332: 281-285.

Awad El Karim, M. A.; Hamed, A. S.; Elhaimi, Y. A.; Osma n, Y. (1986) Effects of exposure to Pb among Pb-acid battery factory workers in Sudan. Arch. Environ. Health 41: 261-265.
Axelson, O.; Steenland, K. (1988) Indir ect methods of assessing the effects of tobacco use in occupational studies.

Am. J. Ind. Med. 13: 105-118. Ayatollahi, M. (2002) Study of the impact of blood Pb level on humoral immunity in humans. Toxicol. Ind.

Health 18: 39-44.
Azcona-Cruz, M. I.; Rothenberg, S. J.; Schnaas-Arrieta, L.; Romero-Placeres, M.; Perroni-Hernández, E. (2000) Niveles de plomo en sangre en niños de 8 a 10 años y su relación con la alteración en el sistema visomotor
y del equilibrio [Relationship of blood Pb levels with visual-motor and equilibrium disturbances in children
aged 8 to 10 yrs]. Salud Publica Mex. 42: 279-287. Baghurst, P. A.; McMichael, A. J.; Wigg, N. R.; Vimpani, G. V.; Robertson, E. F.; Roberts, R. J.; Tong, S.-L.
(1992) Environmental exposure to Pb and children's intelligence at the age of seven yrs: the Port Pirie cohort study. N. Engl. J. Med. 327: 1279-1284.

# AX6-262 Baghurst, P. A.; McMichael, A. J.; Tong, S.; Wigg, N. R.; Vimpani, G. V.; Robertson, E. F. (1995) Exposure to
environmental Pb and visual-motor integration at age 7 yrs: the Port Pirie cohort study. Epidemiology 6:

104-109.

Bairati, C.; Goi, G.; Bollini, D.; Ro ggi, C.; Luca, M.; Apostoli, P.; Lomb ardo, A. (1997) Effects of Pb and
manganese on the release of lysosomal enzymes in vitro and in vivo. Clin. Chim. Acta 261: 91-101. Baird, D. D.; Wilcox, A. J.; Weinberg, C. R. (1986) Use of time to pregnancy to study environmental exposures.
Am. J. Epidemiol. 124: 470-480.
Baker, E. L., Jr.; Landrigan, P. J.; Barbour, A. G.; Cox, D. H.; Folland, D. S.; Ligo, R. N.; Throckmorton, J. (1979) Occupational Pb poisoning in the United States: clinical and biochemical findings related to blood Pb

levels. Br. J. Ind. Med. 36: 314-322.

Balbus, J. M.; Stewart, W.; Bolla, K. I.; Schwartz, B. S. (1 997) Simple visual react ion time in organolead manufacturing workers: comparison of different methods of modeling Pb exposure and reaction time. Am.

J. Ind. Med. 32: 544-549.

Balbus, J. M.; Stewart, W.; Bolla, K. I.; Schwartz, B. S. (1 998) Simple visual react ion time in organolead
manufacturing workers: influence of the interstimulus interval. Arch. Environ. Health 53: 264-270.
Balbus-Kornfeld, J. M.; Stewart, W.; Bolla, K. I.; Schwartz, B. S. (1995) Cumulative exposure to inorganic Pb and neurobehavioural test performance in adults: an epidemiological review. Occup. Environ. Med. 52: 2-12.
Ball, G. V.; Sorensen, L. B. (1969) Pathogenesis of hyperuricemia in saturnine gout. N. Engl. J. Med.

280: 1199-1202. Ballard, J. L.; Novak, K. K.; Driver, M. (1979) A simplif ied score for assessment of fetal maturation of newly born

infants. J. Pediatr. 95: 769-774.
Baloh, R. W.; Spivey, G. H.; Brown, C. P.; Morgan, D.; Campion, D. S.; Browdy, B. L.; Valen tine, J. L. (1979) Subclinical effects of chronic increased Pb absorption - a prospective study. II. Results of baseline
neurologic testing. J. Occup. Med. 21: 490-496.
Barltrop, D. (1969) Transfer of Pb to the human foetus. In: Barltrop, D.; Burl and, W. L., eds. Mineral metabolism in pediatrics. Philadelphia, PA: F. A. Davis Co.; pp. 135-151.
Barth, A.; Schaffer, A. W.; Osterode, W.; Winker, R.; Konnaris, C.; Valic, E.; Wolf, C.; Rüdiger, H. W. (2002)
Reduced cognitive abilities in Pb-exposed men. Int. Arch. Occup. Environ. Health 75: 394-398. Basaran, N.; Ündeger, U. (2000) Effects of Pb on immune parameters in occupationally exposed workers. Am. J.

Ind. Med. 38: 349-354.
Battistuzzi, G.; Petrucci, R.; Silvagni, L. ; Urbani, F. R.; Caiola, S. (1981) δ -aminolevulinate dehydrase: a new genetic polymorphism in man. Ann. Hum. Genet. 45: 233-229.
Batuman, V. (1993) Pb nephropathy, gout, and hypertension. Am. J. Med. Sci. 305: 241-247. Bauchinger, M.; Dresp, J.; Schmid, E.; Englert, N.; Krause, Chr. (1977) Chromosome analyses of children after
ecological Pb exposure. Mutat. Res. 56: 75-80.
Behringer, D.; Craswell, P.; Mohl, C.; Stoeppler, M.; Ritz, E. (1986) Urinar y Pb excretion in uremic patients. Nephron 42: 323-329.
Bellinger, D. C. (1995) Interpreting the literature on Pb and child development: the neglected role of the
"experimental system." Neurotoxicol. Teratol. 17: 201-212. Bellinger, D. C. (2000) Effect modification in epidemiologic studies of low-level neurotoxicant exposures and

health outcomes. Neurotoxicol. Teratol. 22: 133-140.
Bellinger, D. (2002) Perspectives on incorporating human neurobehavioral end points in risk assessments. Risk

Anal. 22: 487-498.
Bellinger, D. C. (2003) Perspectives on incorporating human neurobehavioral end points in risk assessments. Risk

Anal. 23: 163-174. Bellinger, D. C. (2004) Assessing environmental neurotoxicant exposures and child neurobehavior: confounded by
confounding? Epidemiology 15: 383-384.
Bellinger, D. C. (2005) Teratogen update: Pb and pregnancy. Birth Defects Res. Part A 73: 409-420. Bellinger, D. C.; Needleman, H. L. (2003) Intellectual impairment and blood Pb levels [letter]. N. Engl. J. Med. 349:

500. Bellinger, D.; Rappaport, L. (2002) Developmental assessment and interventions. In: Managing elevated blood Pb levels among young children: recommendations from the Advisory Committee on Childhood Pb Poisoning
Prevention. Atlanta, GA: Centers for Disease Control; pp. 79-95. Bellinger, D.; Needleman, H. L.; Bromfield, R.; Mintz, M. (1984) A followup study of the academic attainment and

classroom behavior of children with elevated dentine Pb levels. Biol. Trace Elem. Res. 6: 207-223.

# AX6-263 Bellinger, D.; Leviton, A.; Waternaux, C.; Needleman, H.; Rabinowitz, M. (1987) Longitudinal analyses of prenatal
and postnatal Pb exposure and early cognitive de velopment. N. Engl. J. Med. 316: 1037-1043. Bellinger, D.; Leviton, A.; Waternaux, C.; Needleman, H. ; Rabinowitz, M. (1988) Low-level Pb exposure, social
class, and infant development. Neurotoxicol. Teratol. 10: 497-503.
Bellinger, D.; Leviton, A.; Waternaux, C. (1989) Pb, IQ and social cla ss. Int. J. Epidemiol. 18: 180-185. Bellinger, D.; Leviton, A.; Rabinowitz, M.; Allred, E.; Needleman, H.; Schoenbaum, S. (1991) Weight gain and
maturity in fetuses exposed to low levels of Pb. Environ. Res. 54: 151-158.
Bellinger, D. C.; Stiles, K. M.; Needleman, H. L. (1992) Low-level Pb exposure, intelligence and academic achievement: a long-term follow-up study. Pediatrics 90: 855-861.
Bellinger, D.; Hu, H.; Titlebaum, L.; Needleman, H. L. (19 94a) Attentional correlates of dentin and bone Pb levels

in adolescents. Arch. Environ. Health 49: 98-105. Bellinger, D.; Leviton, A.; Allred, E.; Rabinowitz, M. (1994b) Pre- and postnatal Pb exposure and behavior
problems in school-aged children. Environ. Res. 66: 12-30. Bellinger, D. C.; Hu, H.; Kalaniti, K.; Thomas, N.; Rajan, P.; Sambandam, S.; Ramaswamy, P.; Balakrishnan, K.
(2005) A pilot study of blood Pb levels and neurobehavioral function in children living in Chennai, India.
Int. J. Occup. Environ. Health 11: 138-143. Benetou-Marantidou, A.; Nakou, S.; Micheloyannis, J. (1988) Neurobehavioral estimation of children with life-long
increased Pb exposure. Arch. Environ. Health 43: 392-395.
Benoff, S.; Centola, G. M.; Millan, C.; Napolitano, B.; Ma rmar, J. L.; Hurley, I. R. (2003a) Increased seminal plasma Pb levels adversely affect the fertility pot ential of sperm in IVF. Hum. Reprod. 18: 374-383.
Benoff, S.; Hurley, I. R.; Millan, C.; Napolitano, B.; Cent ola, G. M. (2003b) Seminal Pb concentrations negatively

affect outcomes of artificial insemi nation. Fertil. Steril. 80: 517-525. Bercovitz, K.; Laufer, D. (1991) Age and gender influence on Pb accumulation in root dentine of human permanent

teeth. Arch. Oral Biol. 36: 671-673.
Bergdahl, I. A.; Gerhardsson, L.; Schütz, A.; Desnick, R. J.; Wetmur, J. G.; Skerfving, S. (1997) Deltaaminolevulinic acid dehydratase polymorphism: influence on Pb levels and kidney function in humans.

Arch. Environ. Health 52: 91-96.
Bergeret, A.; Pouget, E.; Tedone, R.; Meygert, T.; Cadot, R.; Descotes, J. (1990) Neutrophil functions in Pbexposed workers. Hum. Exp. Toxicol. 9: 231-233.
Bernard, A. (2004) Renal dysfunction induced by cadmium: biomarkers of critical effects. Biometals 17: 519-523.
Bernard, A.; Thielemans, N.; Roels, H.; Lauwerys, R. (1995a) Association between NAG-B and cadmium in urine with no evidence of a threshold. Occup. Environ. Med. 52: 177-180.
Bernard, A. M.; Vyskocil, A.; Roels, H. ; Kriz, J.; Kodl, M.; Lauwer ys, R. (1995b) Renal effects in children living in the vicinity of a Pb smelter. Environ. Res. 68: 91-95.
Bhattacharya, A.; Shukla, R.; Dietrich, K.; Bornschein, R.; Berger, O. (1995) Effect of early Pb exposure on
children's postural balance. Dev. Med. Child Neurol. 37: 861-878.

Bleecker, M.; Bolla-Wilson, K.; Kawas, C. ; Agnew, J. (1988) Age-specific no rms for the mini-mental state exam.
Neurology 38: 1565-1568.
Bleecker, M. L.; Lindgren, K. N.; Ford, D. P. (1997a) Differential contribution of current and cumulative indices of Pb dose to neuropsychological performance by age. Neurology 48: 639-645.
Bleecker, M. L.; Lindgren, K. N.; Tibu rzi, M. J.; Ford, D. P. (1997b) Curvilinear relationship between blood Pb
level and reaction time. Differential association with blood Pb fractions derived from exogenous and endogenous sources. J. Occup. Environ. Med. 39: 426-431.
Bleecker, M. L.; Lindgren, K. N.; Ford, D. P.; Tiburzi, M. J. (2002) The inte raction of education and cumulative Pb
exposure on the mini-mental state examinatio n. J. Occup. Environ. Med. 44: 574-578. Bleecker, M. L.; Ford, D. P.; Lindgren, K. N.; Scheetz, K.; Tiburzi, M. J. (2 003) Association of chronic and current
measures of Pb exposure with different components of brainstem auditory evoked potentials.
Neurotoxicology 24: 625-631. Bleecker, M. L.; Ford, D. P.; Lindgren, K. N.; Hoese, V. M.; Wa lsh, K. S.; Vaughan, C. G. (2005a) Differential
effects of Pb exposure on components of verbal memory. Occup. Environ. Med. 62: 181-187.
Bleecker, M. L.; Ford, D. P.; Baughan, C. G.; Lindgren, K. N.; Tiburzi, M. J.; Walsh, K. S. (20 05b) Effect of Pb exposure and ergonomic stressors on peripheral nerve function. Environ. Health Perspect. 113: 1730-1734.
Boey, K. W.; Jeyaratnam, J. (1988) A discriminant analysis of neuropsychological effect of low Pb exposure. Toxicology 49: 309-314.
Bogden, J. D.; Thind, I. S.; Louria, D. B.; Caterini, H. (1978) Maternal and cord blood metal concentrations and low
birth weight—a case-control study. Am. J. Clin. Nutr. 31: 1181-1187.

# AX6-264 Bolla, K. I.; Schwartz, B. S.; Stewart, W.; Rignani, J.; Agnew, J.; Ford, D. P. (1995) Comparison of neurobehavioral
function in workers exposed to a mixture of organic and inorganic Pb and in workers exposed to solvents.

Am. J. Ind. Med. 27: 231-246.
Bonde, J. P. E.; Kolstad, H. (1997) Fertility of Danish battery workers ex posed to Pb. Int. J. Epidemiol.

26: 1281-1288. Bonde, J. P.; Joffe, M.; Apostoli, P.; Dale, A. Kiss, P.; Spano, M.; Caruso, F. ; Giwercman, A.; Bisanti, L.; Porru, S.;
Vanhoorne, M.; Comhaire, F.; Zschiesche, W. (2002) Sperm count and chromatin structure in men exposed
to inorganic Pb: lowest adverse effect levels. Occup. Environ. Med. 59: 243-242. Borja-Aburto, V. H.; Hertz-Picciotto, I. ; Lopez, M. R.; Farias, P.; Rios, C.; Blanco, J. (1999) Blood Pb levels
measured prospectively and risk of spontaneous abortion. Am. J. Epidemiol. 150: 590-597.
Bornschein, R. L.; Rabinowitz, M. B. (1985) The second international conference on prospective studies of Pb -

foreword. Environ. Res. 38: 1-2.
Bornschein, R. L.; Grote, J.; Mitchell, T., Succop. P. A.; Dietrich, K. N.; Krafft, K. M.; Hammond, P. B. (1989) Effects of prenatal Pb exposure on in fant size at birth. In: Smith, M. A.; Grant, L. D.; Sors, A. I., eds. Pb
exposure and child development: an international assessment [workshop organized by the Commission of
the European Communities and the U.S. Environmental Protection Agency]; September 1986; Edinburgh, United Kingdom. Dordrecht, The Netherlands: Kluwer Academic Publishers BV; pp. 307-319.
Bost, L.; Primatesta, P.; Dong, W.; Poulter, N. (1999) Blood Pb and blood pressure: evidence from the Health
Survey for England 1995. J. Hum. Hypertens. 13: 123-128. Bound, J. P.; Harvey, P. W.; Francis, B. J.; Awwad, F.; Gatrell, A. C. (1997) Involvement of deprivation and
environmental Pb in neural tube defects: a matched case-control study. Arch. Dis. Child. 76: 107-112.
Bratton, G. R.; Hiney, J. K.; Dees, W. L. (1994) Pb (Pb) alters the norepinephrine-indu ced secretion of luteinizing hormone releasing hormone from the medium eminence of adult male rats in vitro . Life Sci. 55: 563-571.
Braun, C. M. J.; Daigneault, S. (1991) Sparing of cognitive executive functions and impairment of motor functions
after industrial exposure to Pb: a field study with control group. Neuropsychology 5: 179-193. Braunstein, G. D.; Dahlgren, J.; Loriau x, D. L. (1978) Hypogonadism in chronically Pb-poisoned men. Infertility 1:

33-51. Brody, D. J.; Pirkle, J. L.; Kramer, R. A.; Flegal, K. M.; Matte, T. D.; Gu nter, E. W.; Paschal, D. C. (1994) Blood Pb levels in the US population: phase 1 of the third National Health and Nutrition Examination Survey
(NHANES III, 1988 to 1991). JAMA J. Am. Med. Assoc. 272: 277-283.

Buchet, J. P.; Lauwer ys, R.; Roels, H.; Bernard, A.; Bruaux, P.; Claey s, F.; Ducoffre, G.; De Plaen, P.; Staesen, J.; Amery, A.; Linjen, P.; Thijs, L.; Rondia, D.; Sartor, F.; Saint Remy, A.; Nick, L. (1990) Renal effects of
cadmium body burden of the general population. Lancet 336: 699-702. Burns, J. M.; Baghurst, P. A.; Sawyer, M. G.; McMichael, A. J.; Tong, S.-L. (1999) Lifetime low-level exposure to
environmental Pb and children's emotional and behavioral development at ages 11-13 yrs. The Port Pirie
cohort study. Am. J. Epidemiol. 149: 740-749. Campara, P.; D'Andrea, F.; Micciolo, R.; Savonitto , C.; Tansella, M.; Zimmermann-Tansella, C. (1984)
Psychological performance of workers with blood-Pb concentration below the current threshold limit value.
Int. Arch. Occup. Environ. Health 53: 233-246. Campbell, B. C.; Meredith, P. A.; Sc ott, J. J. C. (1985) Pb exposure and changes in the renin-angiotensinaldosterone system in man. Toxicol. Lett. 25: 25-32.
Campbell, J. R.; Moss, M. E.; Rauberta s, R. F. (2000) The association be tween caries and childhood Pb exposure. Environ. Health Perspect. 108: 1099-1102.
Canfield, R. L.; Henderson, C. R., Jr.; Cory-Slechta, D. A.; Cox, C.; Jusko, T. A.; Lanphear, B. P. (2003a)
Intellectual impairment in children with blood Pb concentrations below 10 μ g per deciliter. N. Engl. J.

Med. 348: 1517-1526.

Canfield, R. L.; Kreher, D. A.; Cornwell, C.; Henderson , C. R., Jr. (2003b) Low-level Pb exposure, executive
functioning, and learning in early childhood. Child Neuropsychol. 9: 35-53. Canfield, R. L.; Gendle, M. H.; Cory-Sl echta, D. A. (2004) Impaired neuropsychological functioning in Pb-exposed
children. Dev. Neuropsychol. 26: 513-540.
Cantarow, A.; Trumper, M. (1944) Pb poisoning. Baltimore, MD: Williams & Wilkins Co.

Cárdenas, A.; Roels, H.; Bernard, A. M.; Barbon, R.; Buchet, J. P.; Lauwerys, R. R.; Roselló, J.; Ramis, I.; Mutti,

A.; Franchini, I.; Fels, L. M.; Stolte, H.; De Broe, M. E.; Nuyts, G. D.; Taylor, S. A.; Price, R. G. (1993) Markers of early renal changes induced by industrial pollutants. II. Application to workers exposed to Pb.

Br. J. Ind. Med. 50: 28-36.

# AX6-265 Cardozo dos Santos, A.; Colacciopo, S.; Bó, C. M. R. dal; Santos, N. A. G. dos. (1994) Occupational exposure to
Pb, kidney function tests, and blood pressure. Am. J. Ind. Med. 26: 635-643.
Carta, P.; Cocco, P.; Picchiri, G. ( 1994) Lung cancer mortality and airway s obstruction among metal miners exposed
to silica and low levels of radon daughters. Am. J. Ind. Med. 25: 489-506.

Carta, P.; Aru, G.; Cadeddu, C.; Nieddu , V.; Polizzi, M.; Nurchis, P.; Flore, C.; Salis, S.; Randaccio, F. S. (2003) Mortalità per cancro polmonare in lavoratori di una fonderia di piombo della Sardegna [Follow-up: 1972-
2001] [Lung cancer mortality among workers of a Sardinian Pb smelte r]. G. Ital. Med. Lav. Ergon.
25(suppl. 3): 17-18.

Carta, P.; Aru, G.; Nurchis, P.; Cade ddu, C.; Polizzi, M.; Nieddu , V.; Salis, G.; Gaviano, L.; Flore, C.; Randaccio,
F. S. (2005) Studio di mortalità per cause specifiche in lavoratori di una fonderia di piombo e zinco della
Sardegna. G. Ital. Med. Lav. Ergon. 27(suppl. 1): 43-45. Casey, C. E.; Robinson, M. F. (1978) Copper, manganese, zinc, nickel, cadmium and Pb in human foetal tissue. Br.

J. Nutr. 39: 639-646.

Cavalleri, A.; Trimarchi, F.; Gelmi, C.; Baruffini, A.; Minoia, C.; Biscaldi, G.; Gallo, G. (1982) Effects of Pb on the
visual system of occupationally exposed subjects. Scan d. J. Work Environ. Health 8(suppl. 1): 148-151.

Cecil, K. M.; Yuan, W.; Holland, S.; Wessel, S.; Dietri ch, K.; Ris, D.; Lanphear, B. (2005) The influence of childhood Pb exposure on language function in young adults: an fMRI study. Presented at: International
Society for Magnetic Resonance Imaging: 12th scientif ic meeting and exhibition; May; Miami, FL; A1443.
Centers for Disease Control and Prevention. (1991) Preventing Pb poisoning in young children: a statement by the

Centers for Disease Control. Atlanta, GA: U.S. De partment of Health and Human Services; October.

Centers for Disease Control and Preventio n. (1993) Pb poisoning associated with use of traditional ethnic remedies.
Morb. Mortal. Wkly. Rep. 42: 521-524.

Centers for Disease Control and Preven tion. (1997) Update: blood Pb levels - United States, 1991-1994. Morb.
Mortal. Wkly. Rep. 46: 141-146.
Centers for Disease Control and Prevention. (2000) Blood Pb levels in young children

― United States and selected states, 1996-1999. Morb. Mortal. Wkly. Rep. 49: 1133-1137.
Centers for Disease Control and Prevention. (2005) Preventing Pb poisoning in young children: a statement by
the Centers for Disease Control - August 2005. Atlanta, GA: U.S. Department of Health & Human Services, Public Health Service. Washington, DC: U.S. Environmental Protection Agency; document
ID EPA-HQ-ORD-2004-0018-0105.1. Available: http://www.regulations.gov/fdmspublic/component/main
[5 July, 2006]. Chalkley, S. R.; Richmond, J.; Barltrop, D. (1998) Measurement of vitamin D 3 

# metabolites in smelter workers
exposed to Pb and cadmium. Occup. Environ. Med. 55: 446-452. Chancellor, A. M.; Slattery, J. M.; Fraser, H.; Warlow, C. P. (1993) Risk factors for motor neuron disease: a casecontrol study based on patients from the Scottish Moto r Neuron Disease Register . J. Neurol. Neurosurg.
Psychiatry 56: 1200-1206. Chaube, S.; Swinyard, C. A.; Nishimura, H. (1972) A quantitative study of human embryonic and fetal Pb
with considerations of maternal fetal Pb gradients and the effect of Pb on human reproduction. Teratology

5: 253. Chen, A.; Dietrich, K. N.; Ware, J. H.; Radcliffe, J.; Rogan, W. J. (2005) IQ and blood Pb from 2 to 7 yrs of age: are
the effects in older children the residual of high blood Pb concentrations in 2-yr-olds? Environ. Health
Perspect. 113: 597-601. Chen, A.; Rhoads, G. G.; Cai, B.; Salganik, M.; Rogan, W. J. (2006) The effect of chelation on blood pressure in Pbexposed children: a randomized study. Environ. Health Perspect. 114: 579-583.
Cheng, Y.; Schwartz, J.; Vokonas, P. S.; Weiss, S. T.; Aro, A.; Hu, H. (1998) Electrocardiographic conduction disturbances in association with low-level Pb exposu re (the Normative Aging Study). Am. J. Cardiol.

82: 594-599. Cheng, Y.; Schwartz, J.; Sparrow, D.; Aro, A.; Weiss, S. T.; Hu, H. (2001) Bone Pb and blood Pb levels in relation to baseline blood pressure and the prospective development of hypertension: the Normative Aging Study.
Am. J. Epidemiol. 153: 164-171.
Chia, S. E.; Chua, L. H.; Ng, T. P.; Fo o, S. C.; Jeyaratnam, J. (1994a) Postur al stability of workers exposed to Pb. Occup. Environ. Med. 51: 768-771.
Chia, K. S.; Mutti, A.; Tan, C.; Ong, H. Y.; Jeyaratnam, J.; Ong, C. N. ; Lee, E. (1994b) Urinary N-acetyl- β

- D



# glucosaminidase activity in workers exposed to inorganic Pb. Occup. Environ. Med. 51: 125-129.
Chia, K. S.; Mutti, A.; Alinovi, R.; Jeya ratnam, J.; Tan, C.; Ong, C. N.; Lee, E. (1994c) Urinary excretion of tubular
brush-border antigens among Pb exposed workers. Ann. Acad. Med. Singapore 23: 655-659.

# AX6-266 Chia, K. S.; Jeyaratnam, J.; Tan, C.; Ong, H. Y.; Ong, C. N.; Lee, E. (1995a) Glomerular function of Pb-exposed

workers. Toxicol. Lett. 77: 319-328. Chia, K. S.; Jeyaratnam, J.; Lee, J.; Tan, C.; Ong, H. Y. ; Ong, C. N.; Lee, E. (1995b) Pb-induced nephropathy:
relationship between various biological exposure indices and early markers of nephrotoxicity. Am. J. Ind.

Med. 27: 883-895. Chia, S.-E.; Chia, K.-S; Chia, H.-P.; Ong, C.-N.; Jeya ratnam, J. (1996a) Three-yr follow-up of serial nerve
conduction among Pb-exposed workers. Scand. J. Work Environ. Health 22: 374-380.
Chia, S. E.; Chia, H. P.; Ong, C. N.; Jeyaratnam, J. (1996b) Cumulative blood Pb levels and nerve conduction parameters. Occup. Med. 46: 59-64.
Chia, S. E.; Chia, H. P.; Ong, C. N.; Jeyaratnam, J. (1 996c) Cumulative concentrations of blood Pb and postural
stability. Occup. Environ. Med. 53: 264-268. Chia, S.-E.; Chia, H.-P.; Ong, C.-N.; Jeyaratnam, J. (1997) Cumulative blood Pb levels and neurobehavioral test
performance. Neurotoxicology 18: 793-803. Chia, S. E.; Yap, E.; Chia, K. S. (2004) δ -aminolevulinic acid dehydratase (A LAD) polymorphism and susceptibility
of workers exposed to inorganic Pb and its effects on neurobehavioral functions. Neurotoxicology 25:

1041-1047. Chiodo, L. M.; Jacobson, S. W.; Jacobson, J. L. (2004) Neurodevelopmental effects of postnatal Pb exposure at very

low levels. Neurotoxicol. Teratol. 26: 359-371.
Chowdhury, A. R.; Chinoy, N. J.; Gautam, A. K.; Rao, R. V.; Parikh, D. J.; Shah , G. M.; Highland, H. N.; Patel, K. G.; Chatterjee, B. B. (1986) Effect of Pb on human semen. Adv. Contracept. Delivery Syst. 2: 208-210.
Chu, N.-F.; Liou, S.-H.; Wu, T.-N.; Chang, P.-Y. (1999) Reappraisal of the relation between blood Pb concentration
and blood pressure among the general population in Taiwan. Occup. Environ. Med.

56: 30-33. Chuang, H.-Y.; Schwartz, J.; Tsai, S.-Y.; Lee, M.-L. T.; Wa ng, J.-D.; Hu, H. (2000) Vibration perception thresholds
in workers with long term exposure to Pb. Occup. Environ. Med. 57: 588-594. Chuang, H. Y.; Schwartz, J.; Gonzales-Cossio, T.; Lugo, M. C.; Palazuelos, E.; Aro, A.; Hu, H.; Hernandez-Avila,
M. (2001) Interrelations of Pb levels in bone, venous blood, and umbilical cord blood with exogenous Pb
exposure through maternal plasma Pb in peripartum women. Environ. Health Perspect. 109: 527-532. Chuang, H.-Y.; Yu, K.-T.; Ho, C.-K.; Wu , M.-T.; Lin, G.-T.; Wu, T.-N. (2004) Investigations of vitamin D receptor
polymorphism affecting workers' susceptibility to Pb. J. Occup. Health 46: 316-322.
Chuang, H.-Y.; Chao, K.-Y.; Tsai, S.-Y. (2005) Reversible neurobehavioral performance with reductions in blood Pb levels–a prospective study on Pb workers. Neurotoxicol. Teratol. 27: 497-504.
Clark, A. R. L. (1977) Placen tal transfer of Pb and its effects on the newborn. Post grad. Med. J. 53: 674-678.

Clark, C. S.; Bornschein, R. L.; Succo p, P.; Que Hee, S. S.; Hammond, P. B.; Peace, B. (1985) Condition and type
of housing as an indicator of potential environmental Pb exposure and pediatric blood Pb levels. Environ.

Res. 38: 46-53.

Cocco, P. L.; Carta, P.; Belli, S.; Picchir i, G. F.; Flore, M. V. (1994a) Mortality of Sardinian Pb and zinc miners:
1960-88. Occup. Environ. Med. 51: 674-682.

Cocco, P. L.; Carta, P.; Flore, V.; Picchiri, G. F.; Zucca, C. (1994b) Lung cancer mortality among female mine workers exposed to silica. J. Occup. Med. 36: 894-898.

Cocco, P.; Salis, S.; Anni, M.; Cocco, M. E.; Flore, C.; Ib ba, A. (1995) Effects of short-term occupational exposure
to Pb on erythrocyte glucose-6-phosphate dehydrogenase activity and serum cholesterol. J. Appl. Toxicol.

15: 375-378. Cocco, P.; Carta, P.; Flore, C.; Congia, P.; Manca, M. B.; Saba, G.; Salis, S. (1996) Mortality of Pb smelter workers
with the glucose-6-phosphate dehydrogenase-deficient phenotype. Cancer Epidemiol. Biomarkers Prev. 5:

223-225.

Cocco, P.; Hua, F.; Boffetta, P.; Carta, P. ; Flore, C.; Flore, V.; Onnis, A.; Picch iri, G. F.; Colin, D. (1997) Mortality

of Italian Pb smelter workers. Scand. J. Work Environ. Health 23: 15-23.

Cocco, P.; Dosemeci, M.; Heineman, E. F. (1998a) Brain cancer and occupa tional exposure to Pb. J. Occup.

Environ. Med. 40: 937-942.

Cocco, P.; Dosemeci, M.; Heineman, E. F. (1998b) Occupational risk factor s for cancer of the central nervous system: A case-control study of death certificates fr om 24 U.S. States. Am. J. Ind. Med. 33: 247-255.

Cocco, P.; Ward, M. H.; Dosemeci, M. (1999) Risk of stomach cancer associated with 12 workplace hazards: Analysis of death certificates from 24 states of the United States with the aid of job exposure matrices.
Occup. Environ. Med. 56: 781-787.

Cockcroft, D. W.; Gault, M. H. (1976) Prediction of crea tinine clearance from serum cr eatinine. Nephron 6: 31-41.

# AX6-267 Cohen, N.; Modai, D.; Golik, A.; Weissgarten, J.; Peller, S.; Katz, A.; Averbukh, Z.; Sh aked, U. (1989) Increased
concanavalin A-induced suppressor cell activity in hu mans with occupational Pb exposure. Environ. Res.

48: 1-6. Colleoni, N.; D'Amico, G. (1986) Chronic Pb accumulation as a possible cause of renal failure in gouty patients.
Nephron 44: 32-35. Colleoni, N.; Arrigo, G.; Gandini, E.; Cori gliano, C.; D'Amico, G. (1993) Blood Pb in hemodialysis patients. Am. J.
Nephrol. 13: 198-202.

Constantine, N. A.; Kraemer, H. C.; Kendall-Tackett, K. A.; Bennett, F. C.; Tyson, J. E.; Gross, R. T. (1987) Use of physical and neurologic observations in assessment of gestational age in low birth weight infants. J.
Pediatr. (St. Louis, MO, U.S.) 110: 921-928.
Cooney, G. H.; Bell, A.; McBride, W.; Carter, C. (1989a ) Neurobehavioural consequenc es of prenatal low level exposures to Pb. Neurotoxicol. Teratol. 11: 95-104.
Cooney, G. H.; Bell, A.; McBride, W.; Carter, C. (1989b ) Low-level exposures to Pb: the Sydney Pb study. Dev.

Med. Child Neurol. 31: 640-649.
Cooney, G.; Bell, A.; Stavrou, C. (199 1) Low level exposures to Pb and neurobehavioural development: the Sydney
study at seven yrs. In: Farmer, J. G., ed. Internationa l conference: heavy metals in the environment, v. 1; September; Edinburgh, United Kingdom. Edinburgh, United Kingdom: CEP Consultants, Ltd.; pp. 16-19.
Cooper, W. C. (1988) Deaths from chronic renal disease in U. S. battery and Pb production workers. In: Victery, W.,
ed. Symposium on Pb-blood pressure relationships; Apr il 1987; Chapel Hill, NC. Environ. Health Perspect.

78: 61-63. Cooper, W. C.; Gaffey, W. R. (1975) Mortality of Pb workers. In: Cole, J. F., ed. Proceedings of the 1974
conference on standards of occupational Pb exposure; February 1974; Washington, DC. J. Occup. Med. 17:

100-107. Cooper, W. C.; Tabershaw, I. R.; Nelson, K. W. (1973) La boratory studies of workers in Pb smelting and refining.
In: Barth, D.; Berlin, A.; Engel, R.; Recht, P.; Sm eets, J., eds. Environmental health aspects of Pb: proceedings [of an] international symposium; October 1972; Amsterdam, The Netherlands. Luxembourg:
Commission of the European Communities; pp. 517-530; report no. EUR 5004 d-e-f.
Cooper, W. C.; Wong, O.; Kheifets, L. (1985) Mortality among employees of Pb battery plants and Pb-producing plants, 1947-1980. Scand. J. Work Environ. Health 11: 331-345.

Coratelli, P.; Giannattasio, M.; Lomonte, C.; Marzolla, R.; Rana, F.; L'Abbate, N. (1988) Enzymuria to detect
tubular injury in workers exposed to Pb: a 12-mo follow-up. In: Bianchi, C.; Bocci, V.; Carone, F. A.; Rabkin, R., eds. Kidney and proteins in health and disease: fifth international symposium in health and
disease; July 1987; Montecatini Terme, Italy. Basel, Switzerland: S. Karger; pp. 207-211. Cordioli, G.; Cuoghi, L.; Solari, P. L. ; Berrino, F.; Crosignani, P.; Riboli, E. (1987) Mortalità per tumore in una

coorte di lavoratori della industria del vetro [Tumor mortality in a cohort of glass industry workers].
Epidemiol. Prev. (Italy) 9(30): 16-18. Cory-Slechta, D. A. (1995) Bridging human and experimental animal studies of Pb neurotoxicity: moving beyond
IQ. Neurotoxicol. Teratol. 17: 219-221.
Coscia, G. C.; Discalzi, G.; Ponzetti, C. (1987) Immunolog ical aspects of occupational Pb exposure. Med. Lav.

78: 360-364. Coste, J.; Mandereau, L.; Pessione, F.; Bregu, M.; Faye, C.; Hemon, D.; Spira, A. (1991) Pb-exposed workmen and
fertility: a cohort study on 354 subjects. Eur. J. Epidemiol. 7: 154-158. Counter, S. A.; Buchanan, L. H.; Rosas, H. D.; Ortega, F. (1998) Neurocognitive effects of chronic Pb intoxication

in Andean children. J. Neurol. Sci. 160: 47-53.
Counter, S. A.; Buchanan, L. H. (2002) Neuro-ototoxicity in Andean adults with chronic Pb and noise exposure. J. Occup. Environ. Med. 44: 30-38.

Craswell, P. W.; Price, J.; B oyle, P. D.; Behringer, D.; Stoeppler, M.; Ritz, E. (1987) Patterns of Pb excretion in
patients with gout and chronic renal failure

― a comparative German and Australian study. Sci. Total

Environ. 66: 17-28.
Cullen, M. R.; Kayne, R. D.; Robins, J. M. (1984) Endocrine and reproductive dysfunction in men associated with
occupational inorganic Pb intoxication. Arch. Environ. Health 39: 431-440. Dalpra, L.; Tibiletti, M. G.; Nocera, G.; Giulotto, P.; Aur iti, L.; Carnelli, V.; Simoni, G. (1983) SCE analysis in
children exposed to Pb emission from a smelting plant. Mutat. Res. 120: 249-256.
David, O. J.; Clark, J.; Voeller, K. (1972) Pb and hyperactivity. Lancet (7783): 900-903.
David, O. J.; Hoffman, S. P.; Sverd, J.; Clark, J.; Voeller, K. (1976) Pb and hyperactivity. Behavorial response to
chelation: a pilot study. Am. J. Psychiatry 133: 1155-1158.

# AX6-268 David, O. J.; Clark, J.; Hoffman, S. (1979) Childhood Pb poisoning: a re-evaluation. Arch. Environ. Health

34: 106-111. Davies, J. M. (1984) Lung cancer mortality among worker s making Pb chromate and zinc chromate pigments at
three English factories. Br. J. Ind. Med. 41: 158-169.
Davis, J. M.; Svendsgaard, D. J. (1987) Pb and child development. Nature (London) 329: 297-300. Davis, J. M.; Svendsgaard, D. J. (1990) Nerve conductio n velocity and Pb: a critical review and meta-analysis.
In: Johnson, B. L.; Anger, W. K.; Durao, A.; Xintaras, C., eds. Advances in neurobehavioral toxicology:
applications in environmental and occupational health: [selected papers presented at the third international symposium on neurobehavioral and occupational health]; December 1988; Washington, DC. Chelsea, MI:
Lewis Publishers, Inc.; pp. 353-376.

Davis, J. M.; Otto, D. A.; Weil, D. E. ; Grant, L. D. (1990) The comparative developmental neurotoxicity of Pb in

humans and animals. Neurotoxicol. Teratol. 12: 215-229.

De Burbure, C.; Buchet, J. P.; Bernard, A.; Leroyer, A.; Nisse, C.; Haguenoe r, J.-M.; Bergamaschi, E.; Mutti, A.
(2003) Biomarkers of renal effects in children and adu lts with low environmental exposure to heavy metals.

J. Toxicol. Environ. Health Part A 66: 783-798.

De Burbure, C.; Buchet, J.-P.; Lero yer, A.; Nisse, C.; Haguenoer, J.-M.; Mutti, A.; Smerhovský, Z.; Cikrt, M.; Trczinka-Ochocka, M.; Razniewska, G.; Jakubowski, M.; Bernard, A. (2006) Renal and neurologic effects
of cadmium, Pb, mercury, and arsenic in children: evid ence of early effects and multiple interactions at
environmental exposure levels. Environ. Health Perspect. 114: 584-590. De Kort, W. L. A. M.; Verschoor, M. A.; Wibowo, A. A. E.; van Hemmen, J. J. (1987) Occupational exposure to Pb
and blood pressure: a study in 105 workers. Am. J. Ind. Med. 11: 145-156.
Den Hond, E.; Nawrot, T.; Staessen, J. A. (2002) The relationship between blood pressure and blood Pb in
NHANES III. J. Hum. Hypertens. 16: 563-568. Denno, D. (1990) Biology and violence. From birth to adulthood. New York, NY: Cambridge University Press.
Després, C.; Beuter, A.; Richer, F.; Poitras, K.; Veilleux, A.; Ayotte, P.; De wailly, É.; Saint-Amour, D.; Muckle, G.

(2005) Neuromotor functions in Inuit preschool children exposed to Pb, PCBs, and Hg. Neurotoxicol.

Teratol. 27: 245-257.
Dick, R. B.; Pinkerton, L. E.; Krieg, E. F., Jr.; Biagini, R. E.; Deddens, J. A.; Bri ghtwell, W. S.; Grubb, P. L.; Taylor, B. T.; Russo, J. M. (1999) Evaluation of postur al stability in workers exposed to Pb at a secondary
Pb smelter. Neurotoxicology 20: 595-608.

Dietrich, K. N.; Krafft, K. M.; Bier, M. ; Succop, P. A.; Berger, O.; Bornschein, R. L. (1986) Early effects of fetal Pb exposure: neurobehavioral findings at 6 mos. Int. J. Biosoc. Res. 8: 151-168.

Dietrich, K. N.; Krafft, K. M.; Shukla, R.; Bornschein, R. L.; Succ op, P. A. (1987a) The neurobehavioral effects of early Pb exposure. In: Schroeder, S. R., ed. Toxic substances and mental retardation: neurobehavioral
toxicology and teratology. Washington, DC: American Association on Mental Deficiency; pp. 71-95.
(Begab, M. J., ed. Monographs of the American Association on Mental Deficiency: no. 8).

Dietrich, K. N.; Krafft, K. M.; Bornschein, R. L.; Hamm ond, P. B.; Berger, O.; Succop, P. A.; Bier, M. (1987b)
Low-level fetal Pb exposure effect on neurobehavioral development in early infancy. Pediatrics

80: 721-730. Dietrich, K. N.; Succop, P. A.; Bornschein, R. L.; Krafft, K. M.; Berger, O.; Hammond, P. B.; Buncher, C. R. (1990)
Pb exposure and neurobehavioral development in later infancy. In: Conference on advances in Pb research:
implications for environmental health; January 1989 ; Research Triangle Park, NC. Environ. Health
Perspect. 89: 13-19. Dietrich, K. N.; Succop, P. A.; Berger, O. G.; Hammond, P. B.; Bornschein, R. L. (1991) Pb exposure and the
cognitive development of urban preschool children: the Cincinnati Pb study cohort at age 4 yrs.

Neurotoxicol. Teratol. 13: 203-211.
Dietrich, K. N.; Succop, P. A.; Berger, O. G.; Keith, R. W. (1992) Pb exposure and the central auditory processing
abilities and cognitive development of urban children: the Cincinnati Pb study cohort at age 5 yrs.

Neurotoxicol. Teratol. 14: 51-56.
Dietrich, K. N.; Berger, O. G.; Succop, P. A.; Hammond, P. B.; Bornschein, R. L. (1993a) The developmental
consequences of low to moderate prenatal and postnatal Pb exposure: intellectual attainment in the Cincinnati Pb Study Cohort following school entry. Neurotoxicol. Teratol. 15: 37-44.
Dietrich, K. N.; Berger, O. G.; Succop, P. A. (1993b) Pb exposure and the motor developmental status of urban sixyr-old children in the Cincinnati prospective study. Pediatrics 91: 301-307.
Dietrich, K. N.; Ris, M. D.; Succop, P. A.; Berger, O. G.; Bornschein, R. L. (2001) Early exposure to Pb and
juvenile delinquency. Neurotoxicol. Teratol. 23: 511-518.

# AX6-269 Dietrich, K. N.; Ware, J. H.; Salganik, M.; Radcliffe, J.; Ro gan, W. J.; Rhoads, G. G.; Fay, M. E.; Davoli, C. T.;

Denckla, M. B.; Bornschein, R. L. ; Schwarz, D.; Dockery, D. W.; Adubato, S.; Jones, R. L.; for the Treatment of Pb-Exposed Children Clinical Trial Group. (2004) Eff ect of chelation therapy on the
neuropsychological and behavioral development of Pb-exposed children after school entry. Pediatrics 114:

19-26.

Dietrich, K. N.; Eskenazi, B.; Schantz, S.; Yolton, K.; Rauh, V. A.; Johnson, C. B.; Alkon, A.; Canfield, R. L.;
Pessah, I. N.; Berman, R. F. (2005) Principles and practices of neurodevelopmental assessment in children:

lessons learned from the Centers for Children's Envi ronmental Health and Disease Prevention Research. Environ. Health Perspect. 113: 1437-1446.
Dingwall-Fordyce, I.; Lane, R. E. (1963) A follow-up study of Pb workers. Br. J. Ind. Med. 20: 313-315.
Diouf, A.; Garcon, G.; Thiaw, C.; Diop , Y.; Fall, M.; Ndiaye B.; Siby, T.; Ha nnothiaux, M. H.; Zerimech, F.; Ba, D.; Haguenoer, J. M.; Shirali, P. (2003) Environmenta l Pb exposure and its relationship to traffic density
among Senegalese children: a pilot study. Hum. Exp. Toxicol. 22: 559-564. Discalzi, G. L.; Capellaro, F.; Bottalo, L.; Fabbro, D.; Mocellini, A. (1992) Auditory brainstem evoked potentials
(BAEPS) in Pb-exposed workers. Neurotoxicology 13: 207-209.
Discalzi, G.; Fabbro, D.; Meliga, F.; Mocellini, A.; Capellaro, F. (1993) Effects of occupational exposure to mercury and Pb on brainstem auditory evoked potentials. Int. J. Psychophysiol. 14: 21-25.
Dowd, T. L.; Rosen, J. F.; Gundberg, C. M.; Gupta, R. K. (1994) The displacement of calcium from osteocalcin at
submicromolar concentrations of free Pb. Biochim. Biophys. Acta 1226: 131-137. Driscoll, R. J. (1998) Epidemiologic study of adverse reproductive outcomes among women in the U.S. Forest

Service. In: Driscoll, R. J.; Reh, B. D.; Esswein, E. J. ; Mattorano, D. A. Health hazard evaluation report no.
93-1035-2686, section 2. Washington, DC: U.S. Department of Agriculture, Forest Service; pp. 33-71. Available from: NTIS, Springfield, VA; PB99-152241.
Dursun, N.; Tutus, A. (1999) Chronic oc cupational Pb exposure and thyroid f unction. J. Trace Elem. Exp. Med. 12:

45-49. Duydu, Y.; Süzen, H. S.; Aydin, A.; Cander, O.; Uysal, H. ; Isimer, A.; Vural, N. (2001) Correlation between Pb
exposure indicators and sister chromatid exchange (SCE) frequencies in lymphocytes from inorganic Pb
exposed workers. Arch. Environ. Contam. Toxicol. 41: 241-246. Duydu, Y.; Dur, A.; Süzen, H. S. (2005) Evaluation of increased proportion of cells with unusually high sister
chromatid exchange counts as a cytogenetic biomarker for Pb exposure. Biol. Trace Elem. Res.

104: 121-129. Dye, B. A.; Hirsch, R.; Brody, D. J. (2002) The relationship between blood Pb levels and periodontal bone loss in
the United States, 1988-1994. Environ. Health Perspect. 110: 997-1002. EL-Safty, I. A.; Afifi, A. M.; Shouman, A. E.; EL-Sady, A. K. R. (2004) Effects of smoking and Pb exposure on
proximal tubular integrity among Egyptian industrial workers. Arch. Med. Res. 35: 59-65.
Elwood, P. C.; Davey-Smith, G.; Oldham, P. D.; Toothill, C. (1988a) Two Welsh surveys of blood Pb and blood pressure. In: Victery, W., ed. Symposium on Pb-blood pressure relationships; April 1987; Chapel Hill, NC.
Environ. Health Perspect. 78: 119-121.

Elwood, P. C.; Yarnell, J. W. G.; Oldh am, P. D.; Catford, J. C.; Nutbeam, D.; Davey-Smith, G.; Toothill, C. (1988b) Blood pressure and blood Pb in surveys in Wales. Am. J. Epidemiol. 127: 942-945.

Ehrlich, R.; Robins, T.; Jordaan, E.; Miller, S.; Mbuli, S.; Selby, P.; Wync hank, S.; Cantrell, A.; De Broe, M.;
D'Haese, P.; Todd, A.; Landrigan, P. (1998) Pb absorption and renal dysfunction in a South African battery factory. Occup. Environ. Med. 55: 453-460.
Elmarsafawy, S. F.; Tsaih, S.-W.; Korrick, S.; Dickey, J. H.; Sparrow, D.; Aro, A. ; Hu, H. (2002) Occupational
determinants of bone and blood Pb levels in middle aged and elderly men from the general community: the Normative Aging Study. Am. J. Ind. Med. 42: 38-49.
Emmerson, B. T. (1965) The renal excretion of urate in chronic Pb nephropathy. Australas. Ann. Med.

14: 295-303. Emmerson, B. T.; Ravenscroft, P. J. (1975) Abnormal renal urate homeostasis in systemic disorders. Nephron

14: 62-80. Emory, E.; Ansari, Z.; Pattillo, R.; Archibold, E.; Cheva lier, J. (2003) Maternal blood Pb effects on infant intelligence at age 7 mos. Am. J. Obstet. Gynecol. S26-S32.
Endo, G.; Horiguchi, S.; Kiyota, I. (1990) Urinary N -acetyl- β -D-glucosaminidase activity in Pb-exposed workers. J. Appl. Toxicol. 10: 235-238.
Endo, G.; Konishi, Y.; Kiyota, A.; Horiguchi, S. (1993) Urinary ά 1 

# microglobulin in Pb workers. Bull. Environ.

Contam. Toxicol. 50: 744-749.

# AX6-270 Englyst, V.; Lundstrom, N. G.; Gerhardsson, L.; Rylander, L.; Nordberg, G. (2001) Lung cancer risks among Pb
smelter workers also exposed to arsenic. Sci. Total Environ. 273: 77-82.

Erfurth, E. M.; Gerhardsson, L.; Nilsso n, A.; Rylander, L.; Schütz, A.; Skerfvin g, S.; Börjesson, J. (2001) Effects of
Pb on the endocrine system in Pb smelter workers. Arch. Environ. Health 56: 449-455.
Ernhart, C. B. (1995) In consistencies in the Pb-effects literature exist and cannot be explained by "effect

modification." Neurotoxicol. Teratol. 17: 227-233.
Ernhart, C. B. (2006) Effects of Pb on IQ in children [letter]. Environ. Health Perspect. 114: A85-A86.
Ernhart, C. B.; Greene, T. (1990) Low-level Pb exposure in the prenatal and early preschool periods: language development. Arch. Environ. Health 45: 342-354.

Ernhart, C. B.; Landa, B.; Wolf, A. W. (1985) Subclinical Pb level and developm ental deficit; reanalyses of data. J.
Learning Disabilities 18: 475-479. Ernhart, C. B.; Wolf, A. W.; Kennard, M. J.; Erhard, P.; Filipovich, H. F.; Sokol, R. J. (1986) Intrauterine exposure

to low levels of Pb: the status of the ne onate. Arch. Environ. Health 41: 287-291.

Ernhart, C. B.; Morrow-Tlucak, M.; Marler, M. R.; Wolf, A. W. (1987) Low level Pb exposure in the prenatal and
early preschool periods: early preschool development. Neurotoxicol. Teratol. 9: 259-270.
Ernhart, C. B.; Morrow-Tlucak, M.; Wolf, A. W. (1988) Low level Pb exposure and intelligence in the preschool yrs. Sci. Total Environ. 71: 453-459.
Espy, K. A. (1997) The Shape School: assessing executive function in presch ool children. Dev. Neuropsychol.

13: 495-499.
Ewers, U.; Stiller-Winkler, R.; Idel, H. (1982) Serum im munoglobulin, complement C3, and salivary IgA levels in

Pb workers. Environ. Res. 29: 351-357.

Factor-Litvak, P.; Graziano, J. H.; Klin e, J. K.; Popovac, D.; Mehmeti, A.; Ahmedi, G.; Shrout, P.; Murphy, M. J.; Gashi, E.; Haxhiu, R.; Rajovic, L.; Nenezic, D. U.; Stein, Z. A. (1991) A prospective study of birthweight
and length of gestation in a population surrounding a Pb smelter in Kosovo, Yugoslavia. Int. J. Epidemiol.

20: 722-728. Factor-Litvak, P.; Stein, Z.; Graziano, J. (1993) Increased risk of proteinuria among a cohort of Pb-exposed pregnant
women. Environ. Health Perspect. 101: 418-421.
Factor-Litvak, P.; Kline, J. K.; Popovac, D.; Hadzialjevic, S.; Lekic, V.; Preteni-Rexh epi, E.; Capuni-Paracka, S.; Slavkovich, V.; Graziano, J. (1996) Blood Pb and blood pressure in young children. Epidemiology

7: 633-637. Factor-Litvak, P.; Slavkovich, V.; Liu, X.; Popovac, D.; Preteni, E.; Capuni-Par acka, S.; Hadzialjevic, S.; Lekic, V.; LoIacono, N.; Kline, J.; Graziano, J. (1998) Hyperproduction of erythropoietin in nonanemic Pb-exposed
children. Environ. Health Perspect. 106: 361-364.

Factor-Litvak, P.; Wasserman, G.; Klin e, J. K.; Graziano, J. (1999) The Yugoslavia prospective study of
environmental Pb exposure. Environ. Health Perspect. 107: 9-15.
Fahim, M. S.; Fahim, Z.; Hall, D. G. (1976) Effects of subtoxic Pb levels on pregnant women in the state of

Missouri. Res. Commun. Chem. Pathol. Pharmacol. 13: 309-331.
Fanning, D. (1988) A mortality study of Pb workers, 1926-1985. Arch. Environ. Health 43: 247-251.
Farrow, S. (1994) Falling sp erm quality: fact of fiction? Br. Med. J. 309: 1-2.

Fels, L. M.; Herbort, C. ; Pergande, M.; Jung, K.; Hotter, G.; Roselló, J.; Gelpi, E.; Mutti, A.; De Broe, M.; Stolte, H.
(1994) Nephron target sites in chronic exposure to Pb. Nephrol. Dial. Transplant. 9: 1740-1746.

Fels, L. M.; Wünsch, M.; Baranowski, J.; Norska-Borówka, I. ; Price, R. G.; Taylor, S. A.; Patel, S.; De Broe, M.; Elsevier, M. M.; Lauwerys, R.; Roels, H.; Bernard, A.; Mutti, A.; Gelpi, E.; Roselló, J.; Stolte, H. (1998)
Adverse effects of chronic low level Pb exposure on kidney function

― a risk group study in children.
Nephrol. Dial. Transplant 13: 2248-2256. Fergusson, D. M.; Horwood, L. J. (1993) The effects of Pb levels on the growth of word recognition in middle
childhood. Int. J. Epidemiol. 22: 891-897.
Fergusson, D. M.; Fergusson, J. E.; Horwood, L. J.; Kinzett, N. G. (1988a) A longitudinal study of dentine Pb levels, intelligence, school performance and behaviour. Part II. Dentine Pb and cognitive ability. J. Child
Psychol. Psychiatry Allied Discip. 29: 793-809.
Fergusson, D. M.; Fergusson, J. E.; Horwood, L. J.; Kinzett, N. G. (1988b) A longitudinal study of dentine Pb levels, intelligence, school performance and behaviour. Part III. Dentine Pb levels and attention/activity. J.
Child Psychol. Psychiatry Allied Discip. 29: 811-824. Fergusson, D. M.; Fergusson, J. E.; Horwood, L. J.; Kinzett, N. G. (1988c) A longitudinal study of dentine Pb
levels, intelligence, school performance and behaviour . Part I. Dentine Pb levels and exposure to
environmental risk factors. J. Child Psyc hol. Psychiatry Allied Discip. 29: 781-792.

# AX6-271 Fergusson, D. M.; Horwood, L. J.; Lynskey, M. T. (199 3) Early dentine Pb levels and subsequent cognitive and
behavioural development. J. Child Psychol . Psych. Allied Disciplines 34: 215-227. Fergusson, D. M.; Horwood, L. J.; Lynskey, M. T. (1997) Early dentine Pb levels and educational outcomes at 18
yrs. J. Child Psychol. Psychiatry 38: 471-478. Fewtrell, L. J.; Prüss-Üstün, A.; Landri gan, P.; Ayuso-Mateos, J. L. (2004) Estimating the global burden of disease of mild mental retardation and cardiovascular diseases from environmental Pb exposure. Environ. Res. 94:

120-133. Fiedler, N.; Weisel, C.; Lynch, R.; Kelly-McNeil, K.; We deen, R.; Jones, K.; Udasin, I.; Ohman-Strickland, P.; Gochfeld, M. (2003) Cognitive effects of chronic expo sure to Pb and solvents. Am. J. Ind. Med.

44: 413-423.

Fisch, H.; Andrews, H.; Hendricks, J.; Goluboff, E. T.; Olso n, J. H.; Olsson, C. A. (1997) The relationship of sperm counts to birth rates: a population based study. J. Urol. (Hagerstown, MD, U.S.) 157: 840-843.
Fischbein, A.; Alvares, A. P.; Anderson, K. E.; Sassa, S.; Kappas, A. (1977) Pb intoxication among demolition

workers: the effect of Pb on the he patic cytochrome P-450 systems in hum ans. J. Toxicol. Environ. Health

3: 431-437. Fischbein, A.; Tsang, P.; Luo, J.-C. J.; Roboz, J. P.; Jiang, J. D.; Bekesi, J. G. (1993) Phenotypic aberrations of the

CD3 + 

# and CD4 + 

# cells and functional impairments of lymphocytes at low-level occupational exposure to Pb.
Clin. Immunol. Immunopathol. 66: 163-168.
Fleming, D. E. B.; Chettle, D. R.; Wetmur, J. G.; Desnick, R. J.; Robin, J.-P.; Boulay, D.; Richard, N. S.; Gordon, C. L.; Webber, C. E. (1998) Effect of the delta-aminolevulinate dehydratase polymorphism on the

accumulation of Pb in bone and blood in Pb smelter workers. Environ. Res. 77: 49-61.
Flood, P. R.; Schmidt, P. F.; Wesenberg, G. R.; Gadeholt, H. (1988) The distribution of Pb in human hemopoietic tissue and spongy bone after Pb poisoning and Ca-EDTA chelation therapy: observations made by atomic
absorption spectroscopy, laser micr obeam mass analysis and electron microbeam X-ray analysis. Arch.

Toxicol. 62: 295-300. Folstein, M. F.; Folstein, S. E.; McHugh , P. R. (1975) Mini-Mental State: a practical method of grading the state of
patients for the clinician. J. Psychiatr. Res. 12: 189-198.
Fontanellas, A.; Navarro, S.; Morán-Jiménez, M.-J.; Sánchez-Fructuoso, A. I.; Vegh, I.; Barrientos, A.; De Salamanca, R. E. (2002) Erythrocyte aminolevulinate dehydratase activity as a Pb marker in patients with
chronic renal failure. Am. J. Kidney Dis. 40: 43-50.
Forni, A.; Cambiaghi, G.; Secchi, G. C. (1976) Initial occupational exposure to Pb: chromosome and biochemical findings. Arch. Environ. Health 31: 73-78.

Forni, A.; Sciame’, A.; Bertazzi, P. A.; Alessio, L. (1980) Chromosome and biochemical studies in women occupationally exposed to Pb. Arch. Environ. Health 35: 139-146.
Foster, W. G. (1992) Reproductive toxi city of chronic Pb exposure in th e female cynomolgus monkey. Reprod.

Toxicol. 6: 123-131.

Fracasso, M. E.; Perbellin i, L.; Solda, S.; Talamini, G. ; Franceschetti, P. (2 002) Pb induced DNA strand breaks
in lymphocytes of exposed workers: role of reactive oxygen species and protein kinase C. Mutat. Res.

515: 159-169. Franks, P. A.; Laughlin, N. K.; Dierschk e, D. J.; Bowman, R. E.; Meller, P. A. (1989) Effects of Pb on luteal
function in rhesus monkeys. Biol. Reprod. 41: 1055-1062.
Froom, P.; Kristal-Boneh, E.; Benbassat, J., Ashkanazi, R.; Ribak, J. (1999) Pb exposure in battery-factory workers is not associated with anemia. J. Occup. Environ. Med. 41: 120-123.
Fu, H.; Boffetta, P. (1995) Cancer and occupational exposure to inorganic Pb compounds: a meta-analysis of
published data. Occup. Environ. Med. 52: 73-81.

Fulton, M.; Raab, G.; Thomson, G.; Laxen, D.; Hunter, R.; Hepburn, W. (1987) Influence of blood Pb on the ability
and attainment of children in Edinburgh. Lancet (8544): 1221-1226.
Garçon, G.; Leleu, B.; Zerimech, F.; Mare z, T.; Haguenoer, J.-M.; Furon, D.; Sh irali, P. (2004) Biologic markers of oxidative stress and nephrotoxicity as studied in biomonitoring and adverse effects of occupational
exposure to Pb and cadmium. J. Occup. Environ. Med. 46: 1180-1186.
Gartside, P. S. (1988) The relationship of blood Pb levels and blood pressure in NHAN ES II: additional calculations. In: Victery, W., ed. Symposium on Pb-blood pressure relationships; April 1987; Chapel Hill, NC. Environ.
Health Perspect. 78: 31-34. Gemmel, A.; Tavares, M.; Alperin, S.; Soncini, J.; Dani el, D.; Dunn, J.; Crawford, S.; Braveman, N.; Clarkson,
T. W.; McKinlay, S.; Bellinger, D. C. (2002) Blood Pb level and dental caries in school-age children.
Environ. Health Perspect. 110: A625-A630.

# AX6-272 Gennart, J. P.; Bernard, A.; Lauwerys, R. (1992) Assessment of thyroid, testes, kidney and autonomic nervous
system function in Pb-exposed workers. Int. Arch. Occup. Environ. Health 64: 49-57. Gerhardsson, L.; Brune, D.; Nordberg, G. F.; Wester, P. O. (1986) Distribution of cadmium, Pb and zinc in lung,
liver and kidney in long-term exposed smelter workers. Sci. Total Environ. 50: 65-85.
Gerhardsson, L.; Chettle, D. R.; Englyst, V.; Nordberg, G. F.; Nyhlin, H.; Scott, M. C.; Todd, A. C.; Vesterberg, O. (1992) Kidney effects in long term exposed Pb smelter workers. Br. J. Ind. Med. 49: 186-192.
Gerhardsson, L.; Attewell, R.; Chettle, D. R.; Englyst, V. ; Lundström, N.-G.; Nordberg, G. F.; Nyhlin, H.; Scott,
M. C.; Todd, A. C. (1993) In vivo measurements of Pb in bone in long-term exposed Pb smelter workers.

Arch. Environ. Health 48: 147-156.
Gerhardsson, L.; Hagmar, L.; Rylander, L.; Skerfving, S. (1995) Mortality and cancer incidence among secondary
Pb smelter workers. Occup. Environ. Med. 52: 667-672.

Gerr, F.; Letz, R.; Stokes, L.; Chettle, D.; McNeill, F.; Ka ye, W. (2002) Association between bone Pb concentration
and blood pressure among young adults. Am. J. Ind. Med. 42: 98-106.

Gershanik, J. J.; Brooks, G. G.; Little, J. A. (1974) Blood Pb values in pregnant women and their offspring. Am. J.
Obstet. Gynecol. 119: 508-511.

Gil, F.; Pérez, M. L.; Facio, A.; Villanueva, E.; Tojo, R.; Gil, A. (1994) Dental Pb levels in the Galacian population, Spain. Sci. Total Environ. 156: 145-150.

Glenn, B. S.; Stewart, W. F.; Schwar tz, B. S.; Bressler, J. (2001) Relation of alleles of the sodium-potassium
adenosine triphosphatase ά 2 gene with blood pressure and Pb exposure. Am. J. Epidemiol. 153: 537-545.

Glenn, B. S.; Stewart, W. F.; Links, J. M.; Todd, A. C.; Schwartz, B. S. (2 003) The longitudinal association of Pb
with blood pressure. Epidemiology 14: 30-36.

Glickman, L.; Valciukas, J. A.; Lilis, R.; Weisman, I. (1984) Occupational Pb exposu re: effects on saccadic eye movements. Int. Arch. Occup. Environ. Health 54: 115-125.
Gomaa, A.; Hu, H.; Bellinger, D.; Schwar tz, J.; Tsaih, S.-W.; Gonzalez-Cossio, T.; Schnaas, L.; Peterson, K.; Aro,
A.; Hernandez-Avila, M. (2002) Maternal bone Pb as an independent risk factor for fetal neurotoxicity: a prospective study. Pediatrics 110: 110-118.
Gonick, H. C.; Behari, J. R. (2002) Is Pb exposure the principal cause of essential hypertension? Med. Hypotheses

59: 239-246.
Gonick, H. C.; Cohen, A. H.; Ren, Q.; Saldanha, L. F.; Kha lil-Manesh, F.; Anzalone, J.; Sun, Y. Y. (1996) Effect of
2,3-dimercaptosuccinic acid on nephrosclerosis in the Da hl rat. I. Role of reac tive oxygen species. Kidney

Int. 50: 1572-1581.

González-Cossío, T.; Peterson, K. E.; Sa nín, L.-H.; Fishbein, E.; Palazuelos, E.; Aro, A.; Herná ndez-Avila, M.; Hu,
H. (1997) Decrease in birth weight in relation to maternal bone-Pb burden. Pediatrics 100: 856-862.

Goodman, M.; LaVerda, N.; Clarke, C.; Foster, E. D.; Iannuzzi, J.; Mandel, J. (2002) Neurobehavioural testing in
workers occupationally exposed to Pb: systematic review and meta-analysis of publications. Occup.

Environ. Med. 59: 217-223. Governa, M.; Valentino, M.; Visonà, I. (1987) In vitro impairment of human granulocyte functions by Pb. Arch.

Toxicol. 59: 421-425.

Govoni, S.; Battaini, F.; Fernicola, C.; Castelletti, L.; Trabucchi, M. (1987) Pl asma prolactin concentrations in Pb exposed workers. J. Environ. Path oI. Toxicol. Oncol. 7: 13-15.
Goyer, R. A.; Epstein, S.; Bhattachar yya, M.; Korach, K. S.; Pounds, J. (1994) Environmental risk factors for
osteoporosis. Environ. Health Perspect. 102: 390-394. Grandjean, P. (1979) Occupational Pb exposure in Denmark: screening with the haematofluorometer. Br. J. Ind.

Med. 36: 52-58.
Grandjean, P.; Arnvig, E.; Beckmann, J. (1978) Psychological dysfunctions in Pb-exposed workers: relation to biological parameters of exposure. Scand. J. Work Environ. Health 4: 295-303.
Grandjean, P.; Wulf, H. C.; Niebuhr, E. (1983) Sister chromatid exchange in response to variations in occupational
Pb exposure. Environ. Res. 32: 199-204. Grandjean, P.; Hollnagel, H.; Hedegaard, L.; Christensen, J. M.; Larsen, S. (1989) Blood Pb-blood pressure
relations: alcohol intake and hemoglobin as co nfounders. Am. J. Epidemiol. 129: 732-739.
Graves, A. B.; Van Duijn, C. M.; Chandra, V.; Fratiglioni , L.; Heyman, A.; Jorm, A. F.; Kokmen, E.; Kondo, K.;

Mortimer, J. A.; Rocca, W. A.; Shalat, S. L.; Soininen, H.; Hofman , A. (1991) Occupational exposures to

solvents and Pb as risk factors for Alzheimer's diseas e: a collaborative re-analysis of case-control studies. Int. J. Epidemiol. 20(suppl. 2): S58-S61.
Graziano, J. H.; Popovac, D. ; Factor-Litvak, P.; Shrout, P.; Kline, J.; Murphy, M. J.; Zhao, Y.-H.; Mehmeti, A.;
Ahmedi, X.; Rajovic, B.; Zvicer, Z.; Nenezic, D. U.; Lolacono, N. J.; Stein, Z. (1990) Determinants of

# AX6-273 elevated blood Pb during pregnancy in a population surrounding a Pb smelter in Kosovo, Yugoslavia. In:

Conference on advances in Pb rese arch: implications for environmental health; January 1989; Research Triangle Park, NC. Environ. Health Perspect. 89: 95-100.
Graziano, J. H.; Slavkovic, V.; Factorlitvak, P.; Popovac, D.; Ahmedi, X.; Mehmeti, A. (1991) Depressed serum
erythropoietin in pregnant women with elevated blood Pb. Arch. Environ. Health 46: 347-350.

Graziano, J.; Slavkovich, V.; Liu X., Factor-Litvak, P.; Todd, A. (2004) A prospective study of prenatal and
childhood Pb exposure and erythropoietin production. J. Occup. Environ. Med. 46: 924-929.
Greene, T.; Ernhart, C. B. (1993) Dentine Pb and intelligence prior to school entry: a statistical sensitivity analysis. J. Clin. Epidemiol. 46: 323-339.
Greene, T.; Ernhart, C. B.; Boyd, T. A. (1992) Contributions of risk factors to elevated blood and dentine Pb levels
in preschool children. Sci. Total Environ. 115: 239-260. Groth-Marnat, G. (2003) Handbook of psychological assessment. 4th ed. Hoboken, NJ: John Wiley & Sons.
Guidetti, D.; Bondavalli, M.; Sabadini, R.; Marcello, N.; Vinceti, M.; Cavalletti, S.; Marbini, A.; Gemignani, F.;
Colombo, A.; Ferriari, A.; Vivoli, G.; Solime, F. (1 996) Epidemiological survey of amyotrophic lateral
sclerosis in the province of Reggio Emilia, Italy: influence of environmental exposure to Pb.
Neuroepidemiology 15: 301-312.

Gulson, B. L.; Mizon, K. J.; Palmer, J. M.; Korsch, M. J.; Taylor, A. J.; Mahaffey, K. R. (2004) Blood Pb
changes during pregnancy and postpartum with calcium supplementation. Environ. Health Perspect.

112: 1499-1507. Gump, B. B.; Stewart, P.; Reihman, J.; Lonky, E.; Darvill, T.; Matthews, K. A.; Parsons, P. J. (2005) Prenatal and
early childhood blood Pb levels and cardiovascular functioning in 91⁄2 yr old children. Neurotoxicol.

Teratol. 27: 655-665. Gunnarsson, L. G.; Bodin, L.; Söderfeldt, B.; Axelson, O. (1992) A case-control study of motor neurone disease: its
relation to heritability, and occupational exposures, par ticularly to solvents. Br. J. Ind. Med. 49: 791-798.
Guo, T. L.; Mudzinski, S. P.; Lawrence, D. A. (1996a) The heavy metal Pb modulates the expression of both TNF- ά

and TNF- ά receptors in lipopolysaccharide- activated human peripheral blood mononuclear cells. J. Leukoc.

Biol. 59: 932-939.

Guo, T. L.; Mudzinski, S. P.; Lawren ce, D. A. (1996b) Regulation of HLA-DR and invariant chain expression by human peripheral blood mononuclear cells with Pb, interferon- γ , or interleukin-4. Cell. Immunol.

171: 1-9. Gurer-Orhan, H.; Sabir, H.D.; Ozgunes, H. (2004) Correlation between clinical indicators of Pb poisoning and oxidative stress parameters in controls and Pb-exposed workers. Toxicology 195: 147-154. Gustafson, Å.; Hedner, P.; Schütz, A.; Skerfving, S. (1989) Occupational Pb exposure and pituitary function. Int. Arch. Occup. Environ. Health 61: 277-281.
Gustavsson, P.; Plato, N.; Hallqvist, J.; Hogstedt, C.; Lewne, M.; Reuterwall, C.; Sch eele, P. (2001) A populationbased case-referent study of myocardial infarction and occupational exposure to motor exhaust, other combustion products, organic solvents, Pb, and dynamite. stockholm heart epidemiology program (SHEEP)
study group. Epidemiology 12: 222-228.
Gyllenborg, J.; Skakkebaek, N. E.; Nielsen, N. C.; Keiding, N.; Giwercman, A. (1999) Secular and seasonal changes in semen quality among young Danish men: a statistical analysis of semen samples from 1927 donor
candidates during 1977-1995. Int. J. Androl. 22: 28-36.
Hagmar, L.; Strömberg, U.; Bonassi, S.; Hansteen, I.-L.; Knudsen, L. E.; Lindholm, C.; Norppa, H. (2004) Impact of types of lymphocyte chromosomal aberrations on human cancer risk: results from Nordic and Italian

cohorts. Cancer Res. 64: 2258-2263.
Hajem, S.; Moreau, T.; Hannaert, P.; Lellouch, J.; Huel, G.; Hellier, G.; Orssaud, G.; Claude, J. R.; Juguet, B.; Festy, B.; Garay, R. P. (1990) Influence of environmental Pb on membrane ion transport in a French urban
male population. Environ. Res. 53: 105-118.

Hammond, P. B.; Lerner, S. I.; Gartside, P. S.; Hanenson, I. B.; Roda, S. B.; Foulkes, E. C.; Johnson, D. R.; Pesce, A. J. (1980) The relationship of biological indices of Pb exposure to the health status of workers in a
secondary Pb smelter. J. Occup. Med. 22: 475-484.
Haenninen, H.; Hernberg, S.; Mantere, P.; Vesanto, R.; Jalkanen, M. (1978) Psychological performance of subjects with low exposure to Pb. J. Occup. Med. 20: 683-689.
Haenninen, H.; Mantere, P.; Hernberg, S.; Seppalainen, A. M.; Kock, B. (1979) Subjective symptoms in low-level exposure to Pb. Neurotoxicology 1: 333-347.

Hänninen, H.; Aitio, A.; Kovala, T.; Lu ukkonen, R.; Matikainen, E.; Mannelin, T.; Erkkilä, J.; Riihimäki, V. (1998)
Occupational exposure to Pb and neuropsychological dysfunction. Occup. Environ. Med. 55: 202-209.

# AX6-274 Haraguchi, T.; Ishizu, H.; Takehisa, Y.; Kawai, K.; Yoko ta, O.; Terada, S.; Tsuchiya, K.; Ikeda, K.; Morita, K.;
Horike, T.; Kira, S.; Kuroda, S. (2001) Pb content of brain tissue in diffuse neurofibrillary tangles with calcification (DNTC): the possibility of Pb neurotoxicity. Neuroreport 12: 3887-3890.

Harville, E. W.; Hertz-Picciotto, I.; Schramm, M.; Watt-Morse, M.; Chantala, K.; Osterloh, J.; Parsons, P. J.; Rogan,
W. (2005) Factors influencing the difference between maternal and cord blood Pb. Occup. Environ. Med.

62: 263-290. Hatzakis, A.; Salaminios, F.; Kokevi, A.; Katsouyanni, K.; Maravelias, K.; Kalandidi, A.; Koutselinis, A.; Stefanis,
K.; Trichopoulos, D. (1985) Blood Pb and classr oom behaviour of children in two communities with different degree of Pb exposure: evidence of a dose -related effect? In: Lekkas, T. D., ed. International
conference: heavy metals in the environment, v. 1; September; Athens, Greece. Edinburgh, United
Kingdom: CEP Consultants, Ltd.; p. 47.

Hatzakis, A.; Kokkevi, A.; Maravelias, C.; Katsouyanni, K.; Salaminios, F.; Kala ndidi, A.; Koutselinis, A.; Stefanis,
C.; Trichopoulos, D. (1989) Psychometric intelligence de ficits in Pb-exposed children. In: Smith, M. A.; Grant, L. D.; Sors, A. I., eds. Pb exposure and child development: an international assessment [workshop
organized by the Commission of the European Communities and the U.S. Environmental Protection
Agency]; September 1986; Edinburgh, United Kingdom. Dordrecht, The Netherlands: Kluwer Academic Publishers BV; pp. 211-223.
Haynes, E. N.; Kalkwarf, H. J.; Hornung , R.; Wenstrup, R.; Dietrich, K.; Lanphe ar, B. P. (2003) Vitamin D receptor

Fok1 polymorphism and blood Pb concentration in children. Environ. Health Perspect. 111: 1665-1669. He, F. S.; Zhang, S. L.; Li, G.; Zhang, S. C.; Huang, J. X.; Wu, Y. Q. (1988) An electroneurographic assessment of
subclinical Pb neurotoxicity. Int. Arch. Occup. Environ. Health 61: 141-146.
Hellström, L.; Elinder, C.-G.; Dahlberg, B.; Lundberg, M. ; Järup, L.; Persson, B.; Axelson, O. (2001) Cadmium exposure and end-stage renal disease. Am. J. Kidney Dis. 38: 1001-1008.
Hemdan, N. Y. A.; Emmrich, F.; Adham, K.; Wichmann, G.; Lehmann, I.; El-Massry, A.; Ghoneim, H.; Lehmann,
J.; Sack, U. (2005) Dose-dependent modulation of the in vitro cytokine production of human immune competent cells by Pb salts. Toxicol. Sci. 86: 75-83.
Henderson, D. A. (1955) Chroni c nephritis in Queensland. Australas. Ann. Med. 4: 163-177.
Hense, H. W.; Filipiak, B.; Keil, U. (1993) The associatio n of blood Pb and blood pressure in population surveys. Epidemiology 4: 173-179.
Hense, H. W.; Filipiak, B.; Keil, U. (1994) Alcohol consum ption as a modifier of the relation between blood Pb and
blood pressure. Epidemiology 5: 120-123.
Heo, Y.; Lee, B.-K.; Ahn, K.-D.; Lawrence, D. A. (2004) Serum IgE elevation correlates with blood Pb levels in
battery manufacturing workers. Hum. Exp. Toxicol. 23: 209-213.

Hernandez-Avila, M.; Peterson, K. E.; G onzalez-Cossio, T.; Sanin, L. H.; Aro, A.; Schnaas, L.; Hu, H. (2002) Effect
of maternal bone Pb on length and head circumference of newborns and 1-mo-old infants. Arch. Environ.

Health 57: 482-488.

Hernandez-Avila, M.; Gonzalez-Cossio, T.; Hernandez-Av ila, J. E.; Romieu, I.; Peterson, K. E.; Aro, A.;
Palazuelos, E.; Hu, H. (2003) Dietary calcium supplements to lower blood Pb levels in lactating women: a
randomized placebo-controlled tria l. Epidemiology 14: 206-212. Hernández-Ochoa, I.; García-Vargas, G.; López-Carrillo, L.; Rubio-Andrade, M.; Morán- Martínez, J.; Cebrián,
M. E.; Quintanilla-Vega, B. (2005) Low Pb enviro nmental exposure alters semen quality and sperm
chromatin condensation in northern Mexico. Reprod. Toxicol. 20: 221-228. Hernberg, S.; Nikkanen, J.; Mellin, G.; Lilius, H. (1970) δ -aminolevulinic acid dehydrase as a measure of Pb
exposure. Arch. Environ. Health 21: 140-145.
Hertz-Picciotto, I. (2000) The evidence that Pb increases the ri sk for spontaneous abortion. Am. J. Ind. Med.

38: 300-309.

Hertz-Picciotto, I.; Schramm, M.; Watt- Morse, M.; Chantala, K.; Anderson, J. ; Osterloh, J. (2000) Patterns and
determinants of blood Pb during pregnancy. Am. J. Epidemiol. 152: 829-837.
Hill, A. B. (1965) The environment and disease: asso ciation or causation? Proc. R. Soc. Med. 58: 295-300.
Hirata, M.; Kosaka, H. (1993) Effects of Pb exposure on neurophysiological parameters. Environ. Res. 63: 60-69.
Hogstedt, C.; Hane, M.; Agrell, A; Bodin, L. (1983) Neuropsychological test results and symptoms among workers with well-defined long-term exposure to Pb. Br. J. Ind. Med. 40: 99-105.
Holness, D. L.; Nethercott, J. R. (1 988) Acute Pb intoxication in a group of demolition workers. Appl. Ind.
Hyg. 3: 338-341.

Holdstein, Y.; Pratt, H.; Goldsher, M.; Rosen, G.; Shenha v, R.; Linn, S.; Mor, A.; Barkai, A. (1986) Auditory
brainstem evoked potentials in asymptomatic Pb-exposed subjects. J. Laryngol. Otol. 100: 1031-1036.

# AX6-275 Horiguchi, S.; Endo, G.; Kiyota, I. (1987 ) Measurement of total triiodothyronine (T 3 

# ), total thyroxine (T 4 

# ) and
thyroid-stimulating hormone (TSH) levels in Pb-exposed workers. Osaka City Med J. 33: 51-56. Horiguchi, S.; Matsumura, S.; Fukumo to, K.; Karai, I.; Endo, G.; Teramo to, K.; Shinagawa, K.; Kiyota, I.;
Wakitani, F.; Takise, S.; Kawaraya, T. (1991) Erythr ocyte deformability in workers exposed to Pb. Osaka
City Med. J. 37: 149-155.

Hotz, P.; Buchet, J. P.; Bernard, A. ; Lison, D.; Lauwerys, R. (1999) Rena l effects of low-level environmental
cadmium exposure: 5-yr follow-up of a subcohort from the Cadmibel study. Lancet 354: 1508-1513.
Hsiao, C. Y.; Wu, H. D.; Lai, J. S.; Kuo, H. W. (2001) A longitudinal study of the effects of long-term exposure to Pb among Pb battery factory workers in Taiwan (1989-1999). Sci. Total Environ. 279: 151-158.
Hsieh, L. L.; Liou, S. H.; Chen, Y. H.; Tsai, L. C.; Yang , T.; Wu, T. N. (2000) Association between aminolevulinate
dehydrogenase genotype and blood Pb levels in Taiwan. J. Occup. Environ. Med. 42(2): 151-155. Hu, H. (1991) A 50-yr follow-up of childhood plumbism: hypertension, renal function, and hemoglobin levels
among survivors. Am. J. Dis. Child. 145: 681-687. Hu, H.; Milder, F. L.; Burger, D. E. (1991) The use of K X-ray fluores cence for measuring Pb burden in
epidemiological studies: high and low Pb burdens and measurement uncertainty. Environ. Health Perspect.

94: 107-110. Hu, H.; Watanabe, H.; Payton, M.; Korrick, S.; Rotnitz ky, A. (1994) The relationship between bone Pb and
hemoglobin. JAMA J. Am. Med. Assoc. 272: 1512-1517.
Hu, H.; Aro, A.; Payton, M.; Korrick, S.; Sparrow, D.; Weiss, S. T.; Rotnitzky, A. (1996) The relationship of bone and blood Pb to hypertension. The Normative Aging Study. JAMA J. Am. Med. Assoc. 275: 1171-1176.
Hu, H.; Rabinowitz, M.; Smith, D. (1998) Bone Pb as a biological marker in epidem iologic studies of chronic
toxicity: conceptual paradigms. Environ. Health Perspect. 106: 1-8. Hu, J.; La Vecchia, C.; Negri, E.; Chatenoud, L.; Bosetti, C.; Jia, X.; Liu, R.; Huang, G.; Bi, D.; Wang, C. (1999)

Diet and brain cancer in adults: a case-control study in no rtheast China. Int. J. Cancer 81: 20-23. Hu, H.; Wu, M.-T.; Cheng, Y.; Sparrow, D.; Weiss, S.; Kelsey, K. (2001) The δ -aminolevulinic acid dehydratase (ALAD) polymorphism and bone and blood Pb levels in community-exposed men: the Normative Aging
Study. Environ. Health Perspect. 109: 827-832.
Huang, J.; He, F.; Wu, Y.; Zhang, S. (1988) Observations on renal function in workers exposed to Pb. Sci. Total

Environ. 71: 535-537.
Huel, G.; Boudene, C.; Ibrahim, M. A. (1981) Cadmium and Pb content of maternal and newborn hair: relationship
to parity, birth weight, and hypertension. Arch. Environ. health 36: 221-227.

Hunter, J.; Urbanowicz, M. A.; Yule, W.; Lansdown, R. (1985) Automated testing of reaction time and its

association with Pb in children. Int. Ar ch. Occup. Environ. Health 57: 27-34. Hwang, K.-Y.; Lee, B.-K.; Bressler, J. P.; Bolla, K. I.; Stewart, W. F.; Schwartz, B. S. (2002) Protein kinase C
activity and the relations between blood Pb and neurobehavioral function in Pb workers. Environ. Health
Perspect. 110: 133-138. International Agency for Research on Cancer (IARC). (1980) Some metals and metallic compounds. Lyon, France:
International Agency for Research on Cancer. (IARC monographs on the evaluation of the carcinogenic
risk of chemicals to humans: volume 23). International Agency for Research on Cancer (IARC). (2005) Inorganic and organic Pb compounds. Lyon, France:
International Agency for Research on Cancer. (IARC monographs on the evaluation of the carcinogenic
risk of chemicals to humans: volume 87: in preparation). Irgens, Å.; Krüger, K.; Skorve, A. H.; Irgens, L. M. (1998) Reproductive outcome in offspring of parents

occupationally exposed to Pb in Norway. Am. J. Ind. Med. 34: 431-437.
Ishida, M.; Ishizaki, M.; Yamada, Y. (1996) Decreases in postural change of finger blood flow in ceramic painters chronically exposed to low level Pb. Am. J. Ind. Med. 29: 547-553.
Ito, Y.; Niiya, Y.; Kurita, H.; Shima, S.; Sarai, S. (1985) Serum lipid peroxide level and blood superoxide dismutase
activity in workers with occupational exposure to Pb. Int. Arch. Occup. Environ. Health 56: 119-127.
Iwata, T.; Yano, E.; Karita, K.; Dakeishi, M.; Murata, K. (2 005) Critical dose of Pb affecting postural balance in

workers. Am. J. Ind. Med. 48: 319-325.

Jackson, L. W.; Correa-Villaseñor, A.; L ees, P. S. J.; Dominici, F.; Stewart, P. A.; Breysse, P. N.; Matanoski, G. (2004) Parental Pb exposure and total anomalous pulmonary venous return. Birth Defects Res.

Part A 70: 185-193. Järup, L.; Hellström, L.; Alfvèn, T.; Carlsson, M. D.; Grubb, A.; Persson, B.; Pettersson, C.; Spång, G.; Schutz, A.;
Elinder, C.-G. (2000) Low level exposure to cadmium and early kidney damage: the OSCAR study. Occup.

Environ. Med. 57: 668-672.

# AX6-276 Jemal, A.; Graubard, B. I.; Devesa, S. S.; Flegal, K. M. (2002) The association of blood Pb level and cancer
mortality among whites in the United States. Environ. Health Perspect. 110: 325-329. Jiun, Y. S.; Hsien, L. T. (1994) Lipid peroxidation in workers exposed to Pb. Arch. Environ. Health 49: 256-259.
Joffe, M.; Bisanti, L.; Apostoli, P.; Kiss, P.; Dale, A.; Roeleveld, N.; Lindbohm, M.-L.; Sallmén, M.; Vanhoorne,
M.; Bonde, J. P.; Asclepios. (2003) Time to pregnancy and occupational Pb exposure. Occup. Environ.

Med. 60: 752-758.
Johnson, R. J.; Kang, D.-H.; Feig, D.; Kivlighn, S.; Kane llis, J.; Watanabe, S.; Tuttle, K. R.; Rodriguez-Iturbe, B.;
Herrera-Acosta, J.; Mazzali, M. (2003) Is there a pat hogenetic role for uric acid in hypertension and cardiovascular and renal disease? Hypertension 41: 1183-1190.

Jones, S. J.; Williams, A. J.; Kudlac, H.; Hainsworth, I. R.; Morgan, W. D. (1990) The measurement of bone Pb
content in patients with end stage failure. In: Yasumura , S.; Harrison, J. E., eds. In vivo body composition

studies: recent advances. New York, NY: Plenum Pre ss; pp. 259-262. (Basic life sciences: v. 55).
Joseph, C. L. M.; Havstad, S.; Ownby, D. R.; Peterson, E. L.; Maliarik, M. ; McCabe, M. J.; Barone, C.; Johnson, C. C. (2005) Blood Pb levels and risk of asthma. Environ. Health Perspect. 113: 900-904.
Jung, K.-Y.; Lee, S.-J.; Kim, J.-Y.; Hong, Y.-S.; Kim, S.-R.; Kim, D.-I.; Song, J.-B. (1998) Renal dysfunction
indicators in Pb exposed workers. J. Occup. Health 40: 103-109.

Kamel, F.; Umbach, D.; Munsat, T.; Shefner, J.; Hu, H. ; Sandler, D. (2002) Pb exposure and amyotrophic later
sclerosis. Epidemiology 13: 311-319.

Kamel, F.; Umbach, D. M.; Lehman, T. A.; Park, L. P.; M unsat, T. L.; Shefner, J. M.; Sandler, D. P.; Hu, H.; Taylor, J. A. (2003) Amyotrophic lateral sclerosis, Pb, and genetic susceptibility: polymorphisms in the δ

aminolevulinic acid dehydrat ase and vitamin D receptor genes. Enviro n. Health Perspect. 111: 1335-1339.
Kandiloros, D. C.; Goletsos, G. A.; Nikolopoulos, T. P.; Fe rekidis, E. A.; Tsomis, A. S.; Adamopoulos, G. K. (1997)

Effect of subclinical Pb intoxication on la ryngeal cancer. Br. J. C lin. Practice 51: 69-70.
Kannel, W. B. (2000a) Elevated systolic blood pressure as a cardiovascular risk factor. Am. J. Cardiol. 85: 251-255.
Kannel, W. B. (2000b) Risk stratification in hypertension: new insights from the Framingham Study. Am. J.
Hypertens. 13: 3S-10S. Karakaya, A. E.; Ozcagli, E.; Ertas, N.; Sardas, S. (2005) Assessment of abnormal DNA repair responses and
genotoxic effects in Pb exposed workers. Am. J. Ind. Med. 47: 358-363.

Karmaus, W.; Brooks, K. R.; Nebe, T.; Witten, J.; Obi-Osiu s, N.; Kruse, H. (2005) Immune function biomarkers in
children exposed to Pb and organochlorine compounds: a cross-sectional study. Environ. Health Glob.

Access Sci. 4: 1-10. Kaufman, A. S.; Kaufman, N. L. (1983) Kaufman assessment battery for children. Circle Pines, MN: American

Guidance Service. Kauppinen, T.; Riala, R.; Seitsamo, J.; Hernberg, S. (1992 ) Primary liver cancer and occupational exposure. Scand.

J. Work Environ. Health. 18: 18-25.
Kavlock, R. J.; Daston, G. P.; DeRosa, C.; Fenner-Crisp. P. ; Gray, L. E.; Kaattari, S.; Lucier, G.; Luster, M.; Mac,

M. J.; Maczka, C.; Miller, R.; Moore, J.; Rolland, R.; Scott, G.; Sheeha n, D. M.; Sinks, T.; Tilson, H. A.
(1996) Research needs for the risk assessment of health and environmental effects of endocrine disruptors:
a report of the U.S. EPA-sponsored workshop. Environ. Health Perspect. Suppl. 104(4): 715-740.

Kelada, S. N.; Shelton, E.; Kaufma nn, R. B.; Khoury, M. J. (2001) δ -aminolevulinic acid dehydratase genotype and
Pb toxicity: a HuGE review. Am. J. Epidemiol. 154: 1-13.
Khalil-Manesh, F.; Gonick, H. C.; Cohen, A.; Bergamas chi, E.; Mutti, A. (1992) Experimental model of Pb nephropathy. II. Effect of removal from Pb exposure and chelation treatment w ith dimercaptosuccinic acid
(DMSA). Environ. Res 58: 35-54.
Keiding, N.; Skakkebaek, N. E. (1996) Sperm dec line--real or artifact? Fer til. Steril. 65: 450-453. Keiding, N.; Giwercman, A.; Carlsen, E.; Skakkebaek, N. E. (1994) Comment on "Farrow, S. (1994) Falling sperm
quality: fact of fiction? Br. Med. J. 309: 1-2." Br. Med. J. 309: 131.
Kim, R.; Rotnitsky, A.; Sparrow, D.; Weiss, S. T.; Wager, C.; Hu, H. (1996) A longitudinal study of low-level Pb exposure and impairment of renal function. The Normative Aging Study. JAMA J. Am. Med.

Assoc. 275: 1177-1181. Kim, Y.; Lee, H.; Lee, C. R.; Park, D. U.; Yang, J. S.; Park, I. J.; Lee, K. Y.; Lee, M.; King, T. K.; Sohn, N. S.; Cho, Y. S.; Lee, N.; Chung, H. K. (2002) Evaluation of Pb exposure in workers at s econdary Pb smelters in
South Korea: with focus on activity of erythrocyte pyrimidine 5'-nucleotidase (P5N). Sci. Total Environ.

286: 181-189.

# AX6-277 Kimber, I.; Stonard, M. D.; Gidlow, D. A.; Niewola, Z. (1986) Influence of chronic low-level exposure to Pb on
plasma immunoglobulin concentration and cellular immune function in man. Int. Arch. Occup. Environ.

Health 57: 117-125.
Klein, D.; Wan, Y.-J. Y.; Kamyab, S.; Okuda, H.; Sokol, R. Z. (1994) Effects of toxic levels of Pb on gene
regulation in the male axis: increase in messenger ribo nucleic acids and intracellula r stores of gonadotrophs within the central nervous system. Biol. Reprod. 50: 802-811.
Kline, J.; Stein, Z.; Hutzler, M. (1987) Cigarettes, alcohol and marijuana: varyin g associations with birthweight. Int.
J. Epidemiol. 16: 44-51. Klitzman, S.; Sharma, A.; Nicaj, L.; V itkevich, R.; Leighton, J. (2002) Pb poisoning among pregnant women in New
York City: risk factors and screening practices. Bull. N. Y. Acad. Med. 79: 225-237.
Koller, K.; Brown, T.; Spurgeon, A.; Le vy, L. (2004) Recent developments in low-level Pb exposure and intellectual impairment in children. Environ. Health Perspect. 112: 987-994.
Konishi, Y.; Endo, G.; Kiyota, A.; Horiguchi, S. (1994) Fractional clearances of low mo lecular weight proteins in

Pb workers. Ind. Health 32: 119-127.
Koo, W. W. K.; Succop, P. A.; Bornschein, R. L.; Krugwispe, S. K.; Steinchen, J. J.; Tsang, R. C.; Berger, O.G.
(1991) Serum vitamin D metabolites and bone mineralization in young children with chronic low to moderate Pb exposure. Pediatrics 87: 680-687.
Kordas, K.; Lopez, P.; Rosado, J. L.; Vargas, G. G.; Rico, J. A.; Ronquillo, D.; Cebrian, M. E.; Stoltzfus, R. J.
(2004) Blood Pb, anemia, and short stature are inde pendently associated with cognitive performance in

Mexican school children. J. Nutr. 134: 363-371.
Kordas, K.; Stoltzfus, R. J.; López, P.; Rico, J. A.; Rosado, J. L. (2005) Iron and zinc supplementation does not
improve parent orteacher ratings of be havior in first grade Mexican childre n exposed to Pb. J. Pediatr. 147:

632-639. Kordas, K.; Canfield, R. L.; López, P. ; Rosado, J. L.; Vargas, G. G.; Cébrian, M. E.; Rico, J. A.; Ronquillo, D.;
Stoltzfus, R. J. (2006) Deficits in cognitive functio n and achievement in Mexican first-graders with low

blood Pb concentrations. Environ. Res. 100: 371-386.
Korrick, S. A.; Hunter, D. J.; Rotnitzky, A.; Hu, H.; Speize r, F. E. (1999) Pb and hypertension in a sample of
middle-aged women. Am. J. Public Health 89: 330-335. Koster, J.; Erhardt, A.; Stoeppler, M.; Mohl, C.; Ritz, E. (1989) Mobilizable Pb in patients with chronic renal failure.

Eur. J. Clin. Invest. 19: 228-233.
Kovala, T.; Matikainen, E.; Mannelin, T.; Erkkilä, J.; Riihimäki, V.; Hänninen, H.; Aitio, A. (1997) Effects of low level exposure to Pb on neurophysiological functions among Pb battery workers. Occup. Environ. Med. 54:

487-493. Kramer, M. S. (1987) Intrauterine growth and gestational duration determinants. Pediatrics 80: 502-511.

Kramer, M. S.; McLean, F. H. ; Boyd, M. E.; Usher, R. H. (1988) The validity of gestational age estimation by
menstrual dating in term, preterm, and postterm gestations. JAMA J. Am. Med. Assoc. 260: 3306-3308. Krieg, E. F., Jr.; Chrislip, D. W.; Crespo, C. J.; Bri ghtwell, W. S.; Ehrenberg, R. L.; Otto, D. A. (2005) The
relationship between blood Pb levels and neurobehav ioral test performance in NHANES III and related
occupational studies. Public Health Rep. 120: 240-251. Kristal-Boneh, E.; Froom, P.; Yerushalmi, N.; Harari, G.; Ribak, J. (1998) Calcitropic hormones and occupational
Pb exposure. Am. J. Epidemiol. 147: 458-463.

Kristal-Boneh, E.; Coller, D.; Froom, P.; Harari, G.; Ribak, J. (1999) The association between occupational Pb exposure and serum cholesterol and lipoprotein levels. Am. J. Public Health 89: 1083-1087.
Kristensen, P.; Irgens, L. M.; Daltveit, A. K.; Anders en, A. (1993) Perinatal outcome among children of men
exposed to Pb and organic solvents in the pr inting industry. Am. J. Epidemiol. 137: 134-144. Kromhout, D.; Wibowo, A. A. E.; Herber, R. F. M.; Dalderup, L. M.; Heerdink, H.; de Lezenne Coulander, C.;
Zielhuis, R. L. (1985) Trace metals and coronary hear t disease risk indicators in 152 elderly men (the
Zutphen study). Am. J. Epidemiol. 122: 378-385. Kumar, B. D.; Krishnaswamy, K. (1995) Detection of oc cupational Pb nephropathy using early renal markers. J.

Toxicol. Clin. Toxicol. 33: 331-335.
Kuo, H.-W.; Hsiao, T.-Y.; Lai, J.-S. (2001) Immunological effects of long-term Pb exposure among Taiwanese

workers. Arch. Toxicol. 75: 569-573.
Lancranjan, I.; Popescu, H. I.; G ă v ă nescu, O.; Klepsch, I.; Serb ă nescu, M. (1975) Reproductive ability of workmen occupationally exposed to Pb. Arch. Environ. Health 30: 396-401.

# AX6-278 Lanphear, B. P.; Howard, C.; Eberly, S.; Auinger, P.; Kolassa, J.; Weitzman, M.; Schaff er, S. J.; Alexander, K.
(1999) Primary prevention of childhood Pb exposure: a randomized trial of dust control. Pediatrics

103: 772-777. Lanphear, B. P.; Dietrich, K.; Auinger, P.; Cox, C. (2000) Cognitive deficits associated with blood Pb

concentrations < 10 μ g/dL in U.S. children and adolescents. Public Health Rep. 115: 521-529. Lanphear, B. P.; Hornung, R.; Khoury, J.; Yolton, K.; Baghurst, P.; Bellinger, D. C.; Canfield, R. L.; Dietrich,
K. N.; Bornschein, R.; Greene, T.; Rothenberg, S. J.; Needleman, H. L.; Sc hnaas, L.; Wasserman, G.;
Graziano, J.; Roberts, R. (2005) Low-level environmen tal Pb exposure and children's intellectual function: an international pooled analysis. Environ. Health Perspect. 113: 894-899.
Lanphear, B. P.; Hornung, R.; Khoury, J.; Yolton, K.; Dietrich, K. N. (2006) Pb and IQ in children: Lanphear et al.
respond [letter]. Environ. Health Perspect. 114: A86-A87. Last, J. M. (2001) A dictionary of epidemiology. New York, NY: Oxford University Press.
Laudanski, T.; Sipowicz, M.; Modzelewsk i, P.; Bolinski, J.; Szamatowicz, J.; Razniewska, G.; Akerlund, M. (1991) Influence of high Pb and cadmium soil content on human reproductive outcome. Int. J. Gynecol. Obstet.

36: 309-315. Laughlin, N. K.; Bowman, R. E.; Franks, P. A.; Dierschke, D. J. (1987) Altered menstura l cycles in rhesus monkeys induced by Pb. Fundam. Appl. Toxicol. 9: 722-729.
Lauwers, M. C.; Hauspie, R. C.; Susanne, C.; Verheyden, J. (1986) Comparison of biometric data of children with
high and low levels of Pb in the blood. Am. J. Phys. Anthropol. 69: 107-116. Lauwerys, R.; Buchet, J. P.; Roels, H.; Hubermont, G. (1978) Placental transfer of Pb, mercury, cadmium, and
carbon monoxide in women: I. comparison of the frequency distributions of the biological indices in

maternal and umbilical cord blood. Environ. Res. 15: 278-289.

Lazutka, J. R.; Lekevi č ius, R.; Dedonyt ė , V.; Maciulevi č i ū t ė -Gervers, L.; Mierauskien ė , J.; Rudaitien ė , S.; Slapšyt ė

, G. (1999) Chromosomal aberrations and sister-chromatid exchanges in Lithuanian populations: effects of
occupational and environmental exposures. Mutat. Res. 445: 225-239.

Leal-Garza, C.; Moates, D. O. R.; Cerd a-Flores, R. M.; et al. (1986) Frequenc y of sister-chromatid exchanges (SCE)
in Pb exposed workers. Arch. Invest. Med. 17: 267-276.

Lee, B.-K.; Ahn, K.-D.; Lee, S.-S.; Lee, G.-S.; Kim, Y.-B.; Schwartz, B. S. (2000) A comparison of different

Pb biomarkers in their associati ons with Pb-related symptoms. Int. Arch. Occup. Environ. Health

73: 298-304.

Lee, B.-K.; Lee, G.-S.; Stewart, W. F.; Ahn, K.-D.; Sim on, D.; Kelsey, K. T.; Todd, A. C.; Schwartz, B. S. (2001) Associations of blood pressure and hypertension with Pb dose measures and polymorphisms in the vitamin
D receptor and δ -aminolevulinic acid dehydratase genes. Environ. Health Perspect. 109: 383-389.
Lerchl, A. (1995) Evidence for decreasing quality of sperm. Presenta tion of data on sperm concentration was

flawed. Br. Med. J. 311: 569-570.
Lerda, D. (1992) Study of sperm char acteristics in persons occupationally ex posed to Pb. Am. J. Ind. Med.

22: 567-571. Levey, A. S.; Bosc, J. P.; Lewis, J. B.; Greene, T.; Rogers, N.; Roth, D. (1999) A more accurate method to
estimate glomerular filtration rate from serum creatin ine: a new prediction equation. Ann. Intern. Med.

130: 461-470. Levey, A. S.; Coresh, J.; Balk, E.; Kaus z, A. T.; Levin, A.; Steffes, M. W.; Hogg, R. J.; Perrone, R. D.; Lau, J.;
Eknoyan, G. (2003) National kidney foundation practice guidelines for chronic kidney disease: evaluation,

classification, and stratification. Ann. Intern. Med. 139: 137-147.
Leviton, A.; Bellinger, D.; Allred, E. N.; Rabinowitz, M.; Needleman, H.; Schoenbaum, S. (1993) Pre- and postnatal
low-level Pb exposure and children's dysfunction in school. Environ. Res. 60: 30-43.

Lezak, M. D.; Howieson, D. B. ; Loring, D. W.; Hannay, H. J.; Fischer, J. S. (2004) Neuropsychological assessment.
4th ed. New York, NY: Oxford University Press.
Lidsky, T. I.; Schneider, J. S. (2003) Pb neurotoxicity in children: basic mechanisms an d clinical correlates. Brain

126: 5-19.

Lieb elt, E. L.; Schonfeld, D. J.; Gallagher, P. (1999) Elev ated blood Pb levels in child ren are associated with lower
erythropoietin concentrations. J. Pediatr. 134: 107-109. Lilis, R.; Eisinger, J.; Blumberg, W.; Fischbein, A.; Seli koff, I. J. (1978) Hemogl obin, serum iron, and zinc
protoporphyrin in Pb-exposed workers. Environ. Health Perspect. 25: 97-102. Lim, Y. C.; Chia, K. S.; Ong, H. Y.; Ng, V.; Chew, Y. L. (2001) Renal dysfunction in workers exposed to inorganic
Pb. Ann. Acad. Med. Singapore 30: 112-117.

# AX6-279 Lin, J. L.; Huang, P. T. (1994) Body Pb stores and urate excretion in men with chronic renal disease. J. Rheumatol.

21: 705-709. Lin, J.-L.; Lim, P.-S. (1992) Elevated Pb burden in Chinese patients without occupational Pb exposure. Miner.
Electrolyte Metab. 18: 1-5.
Lin, J.-L.; Lim, P.-S. (1994) Does Pb play a role in the development of renal insufficiency in some patients with essential hypertension? J. Hu m. Hypertens. 8: 495-500. Lin, J.-L.; Yeh, K.-H.; Tseng, H.-C.; Chen, W- Y.; Lai, H.-H.; Lin, Y.-C.; Green Cross Health Service Association
Study Group. (1993) Urinary N-acetyl-glucosaminidase excretion and environmental Pb exposure. Am. J. Nephrol. 13: 442-447.
Lin, S.; Hwang, S. A.; Marshall, E. G.; Stone, R.; Chen, J. (1996) Fertility rates among Pb workers and professional
bus drivers: a comparative study. Ann. Epidemiol. 6: 201-208. Lin, S.; Hwang, S.-A.; Marshall, E. G.; Marion, D. (1998) Do es paternal occupational Pb exposure increase the risks
of low birth weight or prematurity? Am. J. Epidemiol. 148: 173-181. Lin, J.-L.; Ho, H.-H.; Yu, C.-C. (1999) Chelation therapy for patients with elevated body Pb burden and progressive
renal insufficiency. A randomized, controlled trial. Ann. Intern. Med. 130: 7-13.
Lin, J.-L.; Tan, D.-T.; Hsu, K.-H.; Yu, C.-C. (2001a) Environmental Pb exposure and progressive renal insufficiency. Arch. Intern. Med. 161: 264-271.
Lin, J.-L.; Yu, C.-C.; Lin-Tan, D.-T.; Ho, H.-H. (2001b) Pb chelation therapy and urat e excretion in patients with
chronic renal diseases and gout. Kidney Int. 60: 266-271.

Lin, J.-L.; Tan, D.-T.; Ho, H.-H.; Yu, C.-C. (2002) Environmental Pb exposure and urate excretion in the general
population. Am. J. Med. 113: 563-568.
Lin, J.-L.; Lin-Tan, D.-T.; Hsu, K.-H.; Yu, C.-C. (2003) Environmental Pb exposure and progression of chronic renal diseases in patients without diabetes. N. Engl. J. Med. 348: 277-286.

Lindbohm, M.-L.; Hemminki, K.; Bonhomme, M. G.; Anttila , A.; Rantala, K.; Heikkila , P.; Rosenberg, M. J.
(1991a) Effects of paternal occupational exposure on spontaneous abortions. Am. J. Public Health

81: 1029-1033.

Lindbohm, M. L.; Sallmen, M.; Anttila, A.; Taskinen, H.; He mminki, K. (1991b) Paternal occupational Pb exposure
and spontaneous abortion. Scand. J. Work Environ. Health 17: 95-103. Lindeman, R. D.; Tobin, J.; Shock, N. W. (1985) Longitudinal studies on the rate of decline in renal function with
age. J. Am. Geriatr. Soc. 33: 278-285. Lindgren, K.; Masten, V.; Ford, D.; Bleecker, M. (1996) Relation of cumula tive exposure to inorganic Pb and neuropsychological test performance. Occup. Environ. Med. 53: 472-477.
Lindgren, K. N.; Masten, V. L.; Tiburzi, M. J.; Ford, D. P.; Bleecker, M. L. (1999) The factor structure of the profile of mood states (POMS) and its relationship to occupational Pb exposure. J. Occup. Environ. Med.

41: 3-10. Lindgren, K. N.; Ford, D. P.; Bleecker , M. L. (2003) Pattern of blood Pb levels over working lifetime and neuropsychological performance. Arch. Environ. Health 58: 373-379.
Liu, X.; Dietrich, K. N.; Radcliffe, J.; Ragan, N. B.; Rhoads, G. G.; Rogan, W. J. (2002) Do children with falling
blood Pb levels have improved cognition? Pediatrics 110: 787-791.
Lockett, C. J.; Arbuckle, D. (1987) Pb, ferritin, zinc, and hypertension. Bull. Environ. Contam. Toxicol.

38: 975-980.

Loeber, R.; Stouthamer-Loeber, M.; Van Kammen, W.; Farr ington, D. P. (1991) Initiation, escalation and desistance in juvenile offending and their correlates. J. Criminal Law Criminol. 82: 36-82.
Loghman-Adham, M. (1998) Aminoaciduria and glycosuria following severe childhood Pb poisoning. Pediatr.
Nephrol. 12: 218-221. López, C. M.; Piñeiro, A. E.; Núñez, N.; Avagnina, A. M.; Villaamil, E. C.; Roses, O. E. (2000) Thyroid hormone
changes in males exposed to Pb in the Buenos Ai res area (Argentina). Pharm acol. Res. 42: 599-602.
Louis, E. D.; Jurewicz, E. C.; Applegate, L.; Factor-Litvak , P.; Parides, M.; Andrews, L.; Slavkovich, V.; Graziano,

J. H.; Carroll, S.; Todd, A. (2003) Association between essentia l tremor and blood Pb concentration.
Environ. Health Perspect. 111: 1707-1711.
Louis, E. D.; Applegate, L.; Graziano, J. H.; Parides, M. ; Slavkovich, V.; Bhat, H. K. (2005) Interaction between

blood Pb concentration and δ -amino-levulinic acid dehydratase gene polymorphisms increases the odds of

essential tremor. Mov. Disord. 20: 1170-1177. Lucchini, R.; Albini, E.; Cortesi, I.; Placidi, D.; Bergamas chi, E.; Traversa, F.; Alessi o, L. (2000) Assessment of
neurobehavioral performance as a function of current and cumulative occupational Pb exposure.
Neurotoxicology 21: 805-811.

# AX6-280 Lundström, N.-G.; Nordberg, G.; Englyst, V.; Gerhardsson, L.; Hagmar, L.; Jin, T.; Ryla nder, L.; Wall, S. (1997)
Cumulative Pb exposure in relation to mortality and lung cancer morbidity in a cohort of primary smelter

workers. Scand. J. Work Environ. Health 23: 24-30.
Lustberg, M.; Silbergeld, E. (2002) Blood Pb levels and mortality. Arch. Intern. Med. 162: 2443-2449.
Lustberg, M. E.; Schwartz, B. S.; Lee, B. K.; Todd, A. C.; Silbergeld, E. K. (2004) The g(894)-t(894)polymorphism in the gene for endothelial nitric oxide synthase and blood pressure in Pb-exposed workers from Korea. J.
Occup. Environ. Med. 46: 584-590.

Lutz, P. M.; Wilson, T. J.; Ireland, A. L.; Gorman, J. S.; Gale, N. L.; Johnson, J. C.; Hewett, J. E. (1999) Elevated immunoglobulin E (IgE) levels in children with exposure to environmental Pb. Toxicology 134: 63-78.
Mahaffey, K. R.; Annest, J. L.; Roberts, J.; Murphy, R. S. (1982) National estimates of blood Pb levels: United

States, 1976-1980. Association with selected demographic and socioeconomic factors. N. Engl. J. Med.

307: 573-579.

Maheswaran, R.; Gill, J. S.; Beevers, D. G. (1993) Blood pressure an d industrial Pb exposure. Am. J. Epidemiol.

137: 645-653. Maizlish, N. A.; Parra, G.; Feo, O. (1995) Neurobehavioural evaluation of Venezuelan workers exposed to inorganic
Pb. Occup. Environ. Med. 52: 408-414. Makino, S.; Shimizu, Y.; Takata, T. (1997) A study on the relationship between blood Pb levels and anemia
indicators in workers exposed to low levels of Pb. Ind. Health 35: 537-541.
Mäki-Paakkanen, J.; Sorsa, M.; Vainio, H. (1981) Chromo some aberrations and sister chromatid exchanges in Pbexposed workers. Hereditas 94: 269-275.
Malcolm, D.; Barnett, H. A. (1982) A mortality study of Pb workers 1925-76. Br. J. Ind. Med. 39: 404-410.
Mallin, K.; Rubin, M.; Joo, E. (1989) Occupational cancer mortality in Illinois white and black males, 1979-1984,

for seven cancer sites. Am. J. Ind. Med. 15: 699-717.
Mantere, P.; Hänninen, H.; Hernberg, S. (1982) Subclinical neurotoxic Pb effects: two-yr follow-up studies with
psychological test methods. Neurobehav. Toxicol. Teratol. 4: 725-727. Marcus, A. H.; Schwartz, J. (1987) Dose-response curves for erythrocyte protoporphyrin vs blood Pb: effects of iron

status. Environ. Res. 44: 221-227.
Markowitz, M. E.; Gundberg, C. M.; Rosen, J. F. (1988) Sequential osteocalcin campling as a biochemical marker

of the success of treatment of mode rately Pb poisoned children [abs tract]. Pediatr. Res. 23: 393A.
Mason, H. J.; Somervaille, L. J.; Wright, A. L.; Chettle, D. R.; Scott, M. C. (1990) Effect of occupational Pb
exposure on serum 1,25-dihydroxyvitamin D levels. Hum. Exp. Toxicol. 9: 29-34.Matte, T. D.; Figueroa, J. P.; Burr, G.; Flesch, J. P.; Keenlyside, R. A.; Baker, E. L. (1989) Pb exposure among Pbacid battery workers in Jamaica. Am. J. Ind. Med. 16: 167-177.

McBride, W. G.; Carter, C. J.; Bratel, J. R.; Cooney, G.; Bell, A. (1989) The Sydn ey study of health effects of Pb in

urban children. In: Smith, M. A.; Gran t, L. D.; Sors, A. I., eds. Pb exposure and child development: an
international assessment [workshop organized by the Commission of the European Communities and the U.S. Environmental Protection Agency]; September 1986; Edinburgh, United Kingdom. Dordrecht, The
Netherlands: Kluwer Academic Publishers BV; pp. 255-259.
McCabe, M. J.; Lawrence, D. A. (1991) Pb, a major environmental pollutant, is immunomodulatory by its differential effects on CD4+ T cell subsets. Toxicol. Appl. Pharmacol. 111: 13-23.
McCall, R. B. (1979) The development of intellectual f unctioning in infancy and the prediction of later IQ. In:
Osofsky, J. D., ed. Handbook of infant development. New York, NY: John Wiley; pp. 707-741. McDonald, J. A.; Potter, N. U. (1996) Pb's legacy? Earl y and late mortality of 454 Pb-poisoned children. Arch.

Environ. Health. 51: 116-121.
McGregor, A. J.; Mason, H. J. (1990) Chronic occupational Pb exposure and testicular endocrine function. Hum. Exp. Toxicol. 9: 371-376.
McMichael, A. J.; Johnson, H. M. (198 2) Long-term mortality profile of heav ily-exposed Pb smelter workers. J.
Occup. Med. 24: 375-378. McMichael, A. J.; Vimpani, G. V.; Robe rtson, E. F.; Baghurst, P. A.; Clark, P. D. (1986) The Port Pirie cohort
study: maternal blood Pb and pregnancy outcome. J. Epidemiol. Commun. Health 40: 18-25.
McMichael, A. J.; Baghurst, P. A.; Wigg, N. R.; Vimpani, G. V.; Robertson, E. F.; Roberts, R. J. (1988) Port Pirie cohort study: environmental exposure to Pb and children' s abilities at the age of four yrs. N. Engl. J. Med.

319: 468-475. McMichael, A. J.; Baghurst, P. A.; Vimpani, G. V.; Robertson, E. F.; Wigg, N. R.; Tong, S.-L. (1992)
Sociodemographic factors modifying the effect of environmental Pb on neuropsychological development in
early childhood. Neurotoxicol. Teratol. 14: 321-327.

# AX6-281 McMichael, A. J.; Baghurst, P. A.; Vimpani, G. V.; Wigg, N. R.; Robertson, E. F.; Tong, S. (1994) Tooth Pb levels
and IQ in school-age children: the Port Pirie cohort study. Am. J. Epidemiol. 140: 489-499.

McNeill, F. E.; Stokes, L.; Brito, J. A.; Chettle, D. R.; Kaye, W. E. (2000) 109 

# Cd K x -ray fluorescence
measurements of tibial Pb content in young adults exposed to Pb in early childhood. Occup. Environ. Med.

57: 465-471. Menditto, A.; Morisi, G.; Spagnolo, A.; Menotti, A.; NFR Study Group. (1994) Association of blood Pb to blood
pressure in men aged 55 to 75 yrs: effect of select ed social and biochemical co nfounders. NFR study group.
Environ. Health Perspect. 102(suppl. 9): 107-111. Meng, X.-M.; Zhu, D.-M.; Ruan , D.-Y.; She, J.-Q.; Luo, L. (2005) Eff ects of chronic Pb exposure on H MRS of
hippocampus and frontal lobes in children. Neurology 64: 1644-1647.
Meredith, P. A.; Campbell, B. C.; Moor e, M. R.; Goldberg, A. (1977) The e ffects of industrial Pb poisoning on cytochrome P450 mediated phenazone (antipyrine) hydroxylation. Eur. J. Clin. Pharmacol. 12: 235-239.
Meyer-Baron, M.; Seeber, A. (2000) A meta-analysis for ne urobehavioural results due to occupational Pb exposure

with blood Pb concentrations < 70 μ g/100 ml. Arch. Toxicol. 73: 510-518.

Michaels, D.; Zoloth, S. R.; St ern, F. B. (1991) Does lo w-level Pb exposure increase risk of death? A mortality
study of newspaper printers. Int. J. Epidemiol. 20: 978-983.

Min, Y.-I.; Correa-Villaseñor, A.; Stew art, P. A. (1996) Parental occupational Pb exposure and low birth weight.

Am. J. Ind. Med. 30: 569-578.
Mink, P. J.; Goodman, M.; Barraj, L. M.; Imrey, H.; Kelsh, M. A.; Yager, J. (2004) Evaluation of uncontrolled confounding in studies of environmental exposures an d neurobehavioral testing in children. Epidemiology

15: 385-393. Minozzo, R.; Deimling, L. I.; Gigante, L. P.; Santos-Mello, R. (2004) Micronuclei in peripheral blood lymphocytes of workers exposed to Pb. Mutat. Res. 565: 53-60.

Miranda-Carús, E.; Mateos, F. A.; Sanz, A. G.; Herrero, E. ; Ramos, T.; Puig, J. G. (1997) Purine metabolism in
patients with gout: the role of Pb. Nephron 75: 327-335. Mirsky, A. F. (1987) Behavioral and psychophysiological makers of disordered attention. Environ. Health Perspect.

74: 191-199. Mishra, K. P.; Singh, V. K.; Rani, R.; Yadav, V. S.; Chan dran, V.; Srivastava, S. P.; Seth, P. K. (2003) Effect of Pb exposure on the immune response of some occupationally exposed individuals. Toxicology

188: 251-259.

Mitchell, C. S.; Shear, M. S.; Bolla , K. I.; Schwartz, B. S. (1996) Clinical evaluation of 58 organolead manufacturing workers. J. Occup. Environ. Med. 38: 372-378.
Moel, D. I.; Sachs, H. K. (1992) Renal function 17 to 23 yrs after chelation therapy for childhood plumbism. Kidney

Int. 42: 1226-1231. Mohammed-Brahim, B.; Buchet, J. P.; Lauwerys, R. (1985) Erythrocyte pyrimidine 5'-nucleotidase activity in
workers exposed to Pb, mercury or cadmium. Int. Arch. Occup. Environ. Health 55: 247-252.

Moline, J.; Carrillo, L. L.; Sanchez, L. T.; Godbold, J.; Todd, A. (2000) Lactation and Pb body burden turnover: a
pilot study in Mexico. J. Occup. Environ. Med. 42: 1070-1075.
Møller, L.; Kristensen, T. S. (1992) Bl ood Pb as a cardiovascular risk factor. Am. J. Epidemiol. 136: 1091-1100. Moore, M. R.; Goldberg, A.; Bushnell, I. W. R.; Day, R.; Fyfe, W. M. (1982) A prospective study of the
neurological effects of Pb in children. Neurobehav. Toxicol. Teratol. 4: 739-743.
Morgan, J. M. (1975) Chelation therapy in Pb nephropathy. South. Med. J. 68: 1001-1006.

Morita, Y.; Sakai, T.; Araki, S.; Ar aki, T.; Masuyama, Y. (1997) Nicotin amide adenine dinucleotide synthetase
activity in erythrocytes as a tool for the biological monitoring of Pb exposure. Int. Arch. Occup. Environ.

Health 70: 195-198. Morris, C.; McCarron, D. A.; Bennett, W. M. (1990) Low-level Pb exposure, blood pressure, and calcium
metabolism. Am. J. Kidney Dis. 15: 568-574.
Mortada, W. I.; Sobh, M. A.; El-Defrawy, M. M.; Farahat, S. E. (2001) Study of Pb exposure from automobile exhaust as a risk for nephrotoxicity among traffic policemen. Am. J. Nephrol. 21: 274-279.
Mortada, W. I.; Sobh, M. A.; El-Defrawy, M. M. (2004) The exposure to cadmium, Pb and mercury from smoking
and its impact on renal integrity. Med. Sci. Monit. 10: CR112-CR116. Moss, M. E.; Lanphear, B. P.; Auinger, P. (1999) Association of dental caries and blood Pb levels. JAMA J. Am.

Med. Assoc. 281: 2294-2298. Muldoon, S. B.; Cauley, J. A.; Kuller, L. H. ; Morrow, L.; Needleman, H. L. ; Sc ott, J.; Hooper, F. J. (1996) Effects
of blood Pb levels on cognitive function of older women. Neuroepidemiology 15: 62-72.

# AX6-282 Muntner, P.; He, J.; Vupputuri, S.; Coresh, J.; Batuman, V. (2003) Blood Pb and chronic kidney disease in the
general United States population: results fr om NHANES III. Kidney Int. 63: 1044-1050. Murata, K.; Araki, S.; Yokoyama, K.; Uchida, E.; Fujimu ra, Y. (1993) Assessment of central, peripheral, and
autonomic nervous system functions in Pb workers: neuroelectrophysiological studies. Environ.

Res. 61: 323-336. Murphy, M. J.; Graziano, J. H.; Popovac, D.; Kline, J. K.; Mehmeti, A.; Factor-Litvak, P.; Ahmedi, G.; Shrout, P.;
Rajovic, B.; Nenezic, D. U.; Stein, Z. A. (1990) Past pregnancy outcomes among women living in the
vicinity of a Pb smelter in Kosovo, Yugoslavia. Am. J. Public Health 80: 33-35. Nash, D.; Magder, L.; Lustberg, M.; Sherwin, R. W.; Rubin, R. J.; Kaufmann, R. B.; Silbergeld, E. K. (2003) Blood
Pb, blood pressure, and hypertension in perimenopausal and postmenopausal women. JAMA J. Am. Med.

Assoc. 289: 1523-1532. National Toxicology Program. (2003) Report on carcinogens background document for Pb and Pb compounds.
Research Triangle Park, NC: U.S. Department of Health and Human Services. Available: http://ntp.niehs.nih.gov/ntp/newhomeroc/roc11/Pb-Public.pdf [5 May, 2006].
National Toxicology Program. (2004) Pb (CAS no. 7439-92-1) and Pb compounds. In: Report on carcinogens,
eleventh edition. Research Triangle Park, NC: U.S. De partment of Health and Human Services. Available: http://ntp.niehs.nih.gov/ntp/roc/eleventh/pr ofiles/s101Pb.pdf [28 November, 2005].
Navarro, J. A.; Granadillo, V. A.; Salgado, O.; Rodríguez- Iturbe, B.; García, R.; Delling, G.; Romero, R. A. (1992)
Bone metal content in patients with chronic renal failure. Clin. Chim. Acta 211: 133-142.

Navas-Acien, A.; Selvin, E.; Sharrett, A. R.; Calderon-Ara nda, E.; Silbergeld, E.; Gualla r, E. (2004) Pb, cadmium,
smoking, and increased risk of peripheral ar terial disease. Circulation 109: 3196-3201.
Nawrot, T. S.; Thijs, L.; Den Hond, E. M.; Roels, H. A.; Staessen, J. A. (2002) An epidemiological re-appraisal of the association between blood pressure and blood Pb: a meta-analysis. J. Hum. Hypertens. 16: 123-131.
Needleman, H. L. (1995) Environmental Pb and children's intelligence: studies included in the meta-analysis are not
representative [letter]. Br. Med. J. 310: 1408. Needleman, H. L.; Bellinger, D. (1988) Recent developments. Environ. Res. 46: 190-191.
Needleman, H. L.; Gatsonis, C. A. (1990) Low-level Pb ex posure and the IQ of children: a meta-analysis of modern

studies. JAMA J. Am. Med. Assoc. 263: 673-678.

Needleman, H. L.; Gunnoe, C.; Leviton, A.; Reed, R.; Pe resie, H.; Maher, C.; Barrett, P. (1979) Deficits in
psychologic and classroom performance of children with elevated dentine Pb levels. N. Engl. J.

Med. 300: 689-695. Needleman, H. L.; Rabinowitz, M.; Leviton, A.; Linn, S.; Schoenbaum, S. (1984) The relationship between prenatal
exposure to Pb and congenital anomalies. JAMA J. Am. Med. Assoc. 251: 2956-2959. Needleman, H. L.; Schell, A.; Bellinger, D.; Leviton, A.; Al lred, E. N. (1990) The long-term effects of exposure to
low doses of Pb in childhood; an 11-yr follow-up report. N. Engl. J. Med. 322: 83-88.

Needleman, H. L.; Riess, J. A.; Tobi n, M. J.; Biesecker, G. E. ; Greenhouse, J. B. (1996) Bone Pb levels and delinquent behavior. JAMA J. Am. Med. Assoc. 275: 363-369.
Needleman, H. L.; McFarland, C.; Ness, R. B.; Fienberg, S. E.; Tobin, M. J. (2002) Bone Pb levels in adjudcated
delinquents. A case control study. Neurotoxicol. Teratol. 24: 711-717.

Neisser, U.; Boodoo, G.; Bouchard, T. J.; Boykin, A. W.; Brody, N.; Ceci, S. J.; Halpern, D. F.; Loehlin, J. C.;
Perloff, R.; Sternberg, R. J.; Ur bina, S. (1996) Intelligence: knowns and unknowns. Am. Psychol.

51: 77-101.
Nenov, V. D.; Taal, M. W.; Sakharova, O. V.; Brenner, B. M. (2000) Multi-hit nature of chronic renal disease. Curr.
Opin. Nephrol. Hypertens. 9: 85-97.
Neri, L. C.; Hewitt, D.; Orser, B. (19 88) Blood Pb and blood pressure: analys is of cross-sectional and longitudinal data from Canada. In: Victery, W., ed. Symposium on Pb-blood pressure relationships; April 1987; Chapel
Hill, NC. Environ. Health Perspect. 78: 123-126.
Ng, T. P.; Goh, H. H.; Ng, Y. L.; Ong, H. Y.; Ong, C. N.; Chia, K. S.; Chia, S. E.; Jeyaratnam, J. (1991) Male endocrine functions in workers with moderate exposure to Pb. Br. J. Ind. Med. 48: 485-491.
Niu, Q.; He, S. C.; Li, H. Y.; Wang, J. Y.; Dai, F. Y.; Chen, Y. L. (2000) A comprehensive neurobehavioral and
neurophysiological study for low level Pb-exposed workers. G. Ital. Med. Lav. Ergon. 22: 299-304. Nolte, J. (1993) The human brain: an introduction to its functional anatomy. St. Louis, MO: Mosby Yr Book

Publishers. Nomiyama, K.; Nomiyama, H.; Liu, S. J.; Tao, Y. X.; Nomiyama, T.; Omae, K. (2002) Pb induced increase of blood
pressure in female Pb workers. Occup. Environ. Med. 59: 734-738.

# AX6-283 Noonan, C. W.; Sarasua, S. M.; Campagna, D.; Kathman, S. J.; Lybarger, J. A.; Mueller, P. W. (2002) Effects
of exposure to low levels of environmental cadmium on renal biomarkers. Environ. Health Perspect.

110: 151-155. Nordberg, M.; Winblad, B.; Fratiglioni, L.; Basun, H. (2000) Pb concentrations in elderly urban people related
to blood pressure and mental performance: results from a population-based study. Am. J. Ind. Med.

38: 290-294. Nordenson, I.; Beckman, G.; Beckman, L.; Nordström, S. (1978) Occupational and environmental risks in and

around a smelter in northern Sweden. IV. Chromosoma l aberrations in workers exposed to Pb. Hereditas
(Lund, Swed.) 88: 263-267.
Nordström, S.; Beckman, L.; Nordenson, I. (1978a) Occupa tional and environmental risks in and around a smelter in
northern Sweden: I. Variations in birth weight. Hereditas (Lund, Swed.) 88: 43-46. Nordström, S.; Beckman, L.; Nordenson, I. (1978b) Occupational and environmental risks in and around a smelter
in northern Sweden: III. Frequencies of spontaneous abortion. Hereditas (Lund, Swed.) 88: 51-54. Nordström, S.; Beckman, L.; Nordenson, I. (1979) Occupational and environmental risks in and around a smelter in
northern Sweden. V. Spontaneous abortion among female employees and decreased birth weight in their
offspring. Hereditas (Lund, Swed.) 90: 291-296. Nuyts, G. D.; Van Vlem, E.; Thys, J.; De Leersnijder, D.; D'Haese, P. C.; Elseviers, M. M.; De Broe, M. E. (1995)
New occupational risk factors for chronic renal failure. Lancet 346: 7-11.
Oishi, H.; Nomiyama, H.; Nomiyama, K.; Tomokuni, K. (1996) Comparison between males and females with respect to the porphyrin metabolic disorders found in workers occupationally exposed to Pb. Int. Arch.
Occup. Environ. Health 68: 298-304. Öktem, F.; Arslan, M. K.; Dündar, B.; Delibas, N.; Gülte pe, M.; Ergürhan Ilhan, I. (2004) Renal effects and erythrocyte oxidative stress in long-term low-leve l Pb-exposed adolescent workers in auto repair
workshops. Arch. Toxicol. 78: 681-687.
Oliver, T. (1911) Pb poisoning and th e race. Br. Med. J. 1(2628): 1096-1098.

Olsen, G. W.; Bodner, K. M.; Ramlow, J. M.; Ross, C. E. ; Lipshultz, L. I. (1995) Have sperm counts been reduced
50 percent in 50 yrs? A statistical mode l revisited. Fertil. Steril. 63: 887-893.
Olsson, I.-M.; Bensryd, I.; Lundh, T.; Ottosson, H.; Skerfving, S.; Oskarsson, A. (2002) Cadmium in blood and

urine

― impact of sex, age, dietary intake, iron status, and former smoking

― association of renal effects.
Environ. Health Perspect. 110: 1185-1190.
Onalaja, A. O.; Claudio, L. (2000) Genetic susceptibility to Pb poisoning. Environ. Health Perspect. Suppl.
108(1): 23-28. Ong, C. N.; Endo, G.; Chia, K. S.; Phoon, W. O.; Ong, H. Y. (1987) Evaluation of renal function in workers with

low blood Pb levels. In: Foá, V.; Emmett, E. A. ; Maroni, M.; Colombi, A., eds. Occupational and
environmental chemical hazards: cellular and biochemical indices for monitoring toxicity. New York, NY:
Halstead Press; pp. 327-333. O'Riordan, M. L.; Evans, H. J. (1974) Absence of significant chromosome damage in males occupationally exposed
to Pb. Nature (London) 247: 50-53.
Orssaud, G.; Claude, J. R.; Moreau, T.; Lellouch, J.; Juguet, B.; Festy, B. (1985) Blood Pb concentration and blood pressure. Br. Med. J. 290: 244.
Osman, K.; Pawlas, K.; Schütz, A.; Gazdzik, M.; Sokal, J. A.; Vahter, M. (1999) Pb exposure and hearing effects in

children in Katowice, Poland. Environ. Res. 80: 1-8. Österberg, K.; Börjesson, J.; Gerhardsson, L.; Schütz, A. ; Skerfving, S. (1997) A neurobehavioural study of longterm occupational inorganic Pb exposure. Sci. Total Environ. 201: 39-51.
Osterloh, J. D.; Selby, J. V.; Bernard, B. P.; Becker, C. E.; Menke, D. J.; Te pper, E.; Ordonez, J. D.; Behrens, B. (1989) Body burdens of Pb in hypertensive nephropathy. Arch. Environ. Health 44: 304-310.
Osterode, W.; Barnas, D.; Geissler, K. (1999) Dose dependent reduction of erythroid progenitor cells and
inappropriate erythropoietin response in exposure to Pb: new aspects of anaemia induced by Pb. Occup.

Environ. Med. 56: 106-109.
Otto, D. A.; Fox, D. A. (1993) Auditory and visual dysfunction following Pb exposure. Presented at: Ninth
international neurotoxicology conference; October 1991; Little Rock, AR. Neurotoxicology 14(2-3):

191-207.Otto, D.; Robinson, G.; Baumann, S.; Schroeder, S.; Mushak, P.; Kleinbaum, D.; Boone, L. (1985) Five-yr followup study of children with low-to-moderate Pb absorption: electrophysiological evaluation. Environ. Res.

38: 168-186.

# AX6-284 Paksy, K.; Gáti, I.; Náray, M.; Rajczy , K. (2001) Pb accumulation in human ova rian follicular fluid, and in vitro
effect of Pb on progesterone production by cultured human ovarian granulosa cells. J. Toxicol. Environ.

Health Part A 62: 359-366.
Palus, J.; Rydzynski, K.; Dziubaltowska, E.; Wyszynska, K.; Natarajan, A. T.; Nilsson, R. (2003) Genotoxic effects
of occupational exposure to Pb and cadmium. Mutat. Res. 540: 19-28. Parkinson, D. K.; Hodgson, M. J.; Bromet, E. J.; Dew, M. A.; Connell, M. M. (1987) Occupational Pb exposure and
blood pressure. Br. J. Ind. Med. 44: 744-748.

Paschal, D. C.; Burt, V.; Caudill, S. P.; Gunter, E. W.; Pirkle, J. L.; Sampson, E. J.; Miller, D. T.; Jackson, R. J. (2000) Exposure of the U.S. population aged 6 yrs and older to cadmium: 1988-1994. Arch. Environ.

Contam. Toxicol. 38: 377-383.
Patterson, C.; Ericson, J.; Manea-Krichten, M.; Shirahata, H. (1991) Natural skeletal levels of Pb in Homo-sapiens
sapiens uncontaminated by technological Pb. Sci. Total Environ. 107: 205-236.
Payton, M.; Hu, H.; Sparrow, D.; Weiss, S. T. (1994) Lo w-level Pb exposure and renal function in the normative aging study. Am. J. Epidemiol. 140: 821-829.
Payton, M.; Riggs, K. M.; Spiro, A., III; Weiss, S. T.; Hu, H. (1998) Relations of bone and blood Pb to cognitive
function: the VA Normative Aging Study. Neurotoxicol. Teratol. 20: 19-27.

Perez-Bravo, F.; Ruz, M; Moran-Jimen ez, M. J.; Olivares, M.; Rebolledo, A.; Codoceo, J.; Sepulveda, J.; Jenkin, A.;
Santos, J. L.; Fontanellas, A. (2004) Association between aminolevulinate dehydrase genotypes and blood
Pb levels in children from a Pb-contaminated area in Antofagasta, Chile. Arch. Environ. Contam. Toxicol.
47(2): 276-280. Pergande, M.; Jung, K.; Precht, S.; Fels, L. M.; Herbort, C.; Stolte, H. (1994) Changed excretion of urinary proteins
and enzymes by chronic exposure to Pb. Nephrol. Dial. Transplant. 9: 613-618. Pesch, B.; Haerting, J.; Ranft, U. ; Klimpel, A.; Oelschlägel, B.; Sc hill, W.; MURC Study Group. (2000)
Occupational risk factors for renal cell carcinoma: agent-specific resu lts from a case-control study in
Germany. Int. J. Epidemiol. 29: 1014-1024. Philion, J. J.; Schmitt, N.; Rowe, J.; Gelp ke, P. M. (1997) Effect of Pb on fetal growth in a Canadian smelter city,

1961-1990. Arch. Environ. Health 52: 472-475.
Pineda-Zavaleta, A. P.; García-Vargas, G.; Borja-Aburto, V. H.; Acosta-Saaved ea, L. C.; Vera Aguilar, E.; GómezMuñoz, A.; Cebrián, M. E. Calderón-Aranda, E. S. (2004) Nitric oxide and superoxide anion production in
monocytes from children exposed to arsenic and Pb in region Lagunera, Mexico. Toxicol. Appl.

Pharmacol. 198: 283-290. Pinkerton, L. E.; Biagini, R. E.; Ward, E. M.; Hull, R. D.; Deddens, J. A.; Boenig er, M. F.; Schnorr, T. M.;

MacKenzie, B. A.; Luster, M. I. (1998) Immunologic findings among Pb-exposed workers. Am. J. Ind.

Med. 33: 400-408.
Pinto de Almeida, A. R.; Carvalho, F. M.; Spinola, A. G.; Rocha, H. (1987) Renal dysfunction in Brazilian Pb
workers. Am. J. Nephrol. 7: 455-458. Piomelli, S.; Seaman, C.; Zullow, D.; Curran, A.; Davidow, B. (1982) Threshold for Pb damage to heme synthesis in

urban children. Proc. Natl. Acad. Sci. U. S. A. 79: 3335-3339.
Pirkle, J. L.; Kaufmann, R. B.; Brody, D. J.; Hickman, T.; Gunter, E. W.; Paschal, D. C. (1998) Exposure of the U.S. population to Pb, 1991-1994. Environ. Health Perspect. 106: 745-750.
Pocock, S. J.; Shaper, A. G.; Ashby, D.; Delves, T.; Wh itehead, T. P. (1984) Blood Pb concentration, blood
pressure, and renal function. Br. Med. J. 289: 872-874. Pocock, S. J.; Ashby, D.; Smith, M. A. (1987) Pb expo sure and children's intellectual performance. Int. J.
Epidemiol. 16: 57-67.
Pocock, S. J.; Smith, M.; Baghurst, P. (1994) Environmental Pb and children's intelligence: a systematic review of the epidemiological evidence. Br. Med. J. 309: 1189-1197.
Pollock, C. A.; Ibels, L. S. (1988) Pb intoxication in Sydney Harbour bridge workers. Aust. N. Z. J. Med.

18: 46-52.
Poulos, L.; Qammaz, S.; Athanaselis, S.; Maravelias, C.; Koutselinis, A. (1986) Statistically significant
hematopoietic effects of low blood Pb levels. Arch. Environ. Health 41: 384-386.
Pounds, J. G.; Long, G. J.; Rosen, J. F. (1991) Cellular and molecular toxicity of Pb in bone. Environ. Health
Perspect. 91: 17-32. Price, J.; Grudzinski, A. W.; Craswell, P. W.; Thomas, B. J. (1992) Bone Pb measurements in patients with chronic

renal disease studied over time. Arch. Environ. Health 47: 330-335.

Price, R. G.; Patel, S.; Chivers, I.; Milligan, P.; Taylor, S. A. (1999) Early markers of nephrotoxicity: detection of

children at risk from environmenta l pollution. Renal Fail. 21: 303-308.

# AX6-285 Proctor, S. P.; Rotnitzky, A.; Sparrow, D.; Weiss, S. T.; Hu, H. (1996) The relationship of blood Pb and dietary
calcium to blood pressure in the normative aging study. Int. J. Epidemiol. 25: 528-536. Prpi ć -Maji ć , D.; Bobi ć , J.; Šimi ć , D.; House, D. E.; Otto, D. A.; Jurasovi ć , J.; Pizent, A. (2000) Pb absorption and
psychological function in Zabreb (Croatia) school children. Neurotoxicol. Teratol. 22: 347-356.
Pueschel, S. M.; Kopito, L.; Schwachman, H. (1972) Child ren with an increased Pb burden. A screening and followup study. JAMA J. Am. Med. Assoc. 222: 462-466.
Puzas, J. E. (2000) Osteotoxicology: the role of Pb in bone disease. Curr. Opin. Orthop. 11: 360-365.
Puzas, J. E.; Sickel, M. J.; Felter, M. E. (1992) Osteoblasts and chondrocytes are important target cells for the toxic effects of Pb. Neurotoxicology 13: 783-788.
Pyatt, D. W.; Zheng, J.-H.; Stillman, W. S.; Irons, R. D. (1996) Inorganic Pb activates NF- κ B in primary human

CD4 + 

# T lymphocytes. Biochem. Biophys. Res. Commun. 227: 380-385.
Queiroz, M. L. S.; Almeida, M.; Gallao, M. I.; Höehr, N. F. (1993) Defective neutrophil function in workers
occupationally exposed to Pb. Pharmacol. Toxicol. 72: 73-77.
Queiroz, M. L.; Costa, F. F.; Bincoletto , C.; Perlingeiro, R. C. R.; Dantas, D. C. M.; Cardoso, M. P.; Almeida, M.
(1994a) Engulfment and killing capabilities of neutrophils and phagocytic splenic function in persons
occupationally exposed to Pb. Int. J. Immunopharmacol. 16: 239-244. Queiroz, M. L. S.; Perlingeiro, R. C. R.; Bincoletto, C.; Almeida, M.; Cardos o, M. P.; Dantas, D. C. M. (1994b)
Immunoglobulin levels and cellular immune function in Pb exposed workers. Immunopharmacol.

Immunotoxicol. 16: 115-128. Raab, G. M.; Thomson, G. O. B.; Boyd , L.; Fulton, M.; Laxen, D. P. H. (1 990) Blood Pb levels, reaction time,
inspection time and ability in Edinburgh chil dren. Br. J. Dev. Ps ychol. 8: 101-118.
Rabinowitz, M. B. (1991) Toxicokinetics of bone Pb. Environ. Health Perspect. 91: 33-37. Rabinowitz, M.; Bellinger, D.; Leviton, A.; et al. (1987) Pregnancy hypertension, blood pressure during labor, and
blood Pb levels. Hypertension 10: 447-451.

Rabinowitz, M. B.; Allred, E. N.; Be llinger, D. C.; Leviton, A.; Needleman, H. L. (1990) Pb and childhood propensity to infectious and allergic disorders: is th ere an association? Bull. Environ. Contam. Toxicol.

44: 657-660. Rabinowitz, M. B.; Bellinger, D.; Leviton, A.; Wang, J.-D. (1991) Pb levels among various deciduous tooth types.

Bull. Environ. Contam. Toxicol. 47: 602-608.
Rabinowitz, M. B.; Wang, J.-D.; Soong, W. T. (1992) Children's classroom behavior and Pb in Taiwan. Bull.

Environ. Contam. Toxicol. 48: 282-288. Rabinowitz, M. B.; Leviton, A.; Bellinge r, D. (1993) Relationships between serial blood Pb levels and exfoliated

tooth dentin Pb levels: models of tooth Pb kinetics. Calcif. Tissue Int. 53: 338-341. Rahman, A.; Hakeem, A. (2003) Blood Pb levels during pregnancy and pregnancy outcome in Karachi women. J.

Pak. Med. Assoc. 53: 529-533.
Rajah, T.; Ahuja, Y. R. (1995) In vivo genotoxic effects of smoking and occupational Pb exposure in printing press

workers. Toxicol. Lett. 76: 71-75.
Rajah, T. T.; Ahuja, Y. R. (1996) In vivo genotoxicity of alcohol consumption and Pb exposure in printing press

workers. Alcohol 13: 65-68. Rajegowda, B. K.; Glass, L.; Evans, H. E. (1972) Pb concentrations in the newborn infant. J. Pediatr. 80: 116-117.

Ratzon, N.; Froom, P.; Leikin, E.; Kristal-B oneh, E.; Ribak, J. (2000) Effect of exposure to Pb on postural control in
workers. Occup. Environ. Med. 57: 201-203. Refowitz, R. M. (1984) Thyroid function and Pb: no clear relationship. J. Occup. Med. 26: 579-583.
Reigart, J. R.; Graber, C. D. (1976) Evaluation of the humoral immune response of children with low level Pb
exposure. Bull. Environ. Contam. Toxicol. 16: 112-117. Reimer, W.; Tittelbach, U. (1989) Verhalten von Herzfreque nz, Blutdruck und systolischen Zeitintervallen in Ruhe
und wahrend Einhandarbeit bei Bleiexponierten und Kontrollpersonen [Heart rate, blood pressure and
systolic time interval in rest and during single-han d exertion in persons exposed to Pb and in control subjects]. Z. Gesamte Hyg. Ihre Grenzgeb. 35: 491-492.
Restek-Samaržija, N.; Mom č ilovi ć , B.; Troši ć , I.; Piasek, M.; Samaržija, M. (1996) Chronic Pb poisoning, renal
function and immune response. Arh. Hig. Rada Toksikol. 47: 1-8. Restek-Samaržija, N.; Mom č ilovi ć , B.; Turk, R.; Samaržija, M. (1997) Contribution of Pb poisoning to renal
impairment. Arh. Hig. Rada Toksikol. 48: 355-364. Rhainds, M.; Levallois, P. (1997) Effects of maternal cigarette smoking and alcohol consumption on blood Pb levels
of newborns. Am. J. Epidemiol. 145: 250-257.

# AX6-286 Rhainds, M.; Levallois, P.; Dewailly, É.; Ayotte, P. (1999) Pb, mercury, and organochlorine compound levels in
cord blood in Québec, Canada. Arch. Environ. Health 54: 40-47. Rhodes, D.; Spiro, A., III; Aro, A.; Hu, H. (2003) Relationship of bone and blood Pb levels to psychiatric
symptoms: The Normative Aging Study. J. Occup. Environ. Med. 45: 1144-1151.
Rico, J. A.; Kordas, K.; López, P.; Rosa do, J. L.; Vargas, G. G.; Ronquillo, D.; Stoltzfus, R. J. (2006) The efficacy of iron and/or zinc supplementation on cognitive performance of Pb-exposed Mexican school children: a
randomized, placebo-contro lled trial. Pediatrics 117: e518-e527.
Ris, M. D.; Dietrich, K. N.; Succop, P. A.; Berger, O. G.; Bornschein, R. L. (2004) Early exposure to Pb and neuropsychological outcome in adolescence. J. Int. Neuropsychol. Soc. 10: 261-270.

Risch, H. A.; Burch, J. D.; Miller, A. B.; Hill, G. B.; Steele, R.; Howe, G. R. (1988) Occupational factors and the

incidence of cancer of the bladder in Canada. Br. J. Ind. Med. 45: 361-367. Robins, J. M.; Cullen, M. R.; Connors, B. B.; Kayne, R. D. (1983) Depressed thyroid indexes associated with
occupational exposure to inorganic Pb. Arch. Intern. Med. 143: 220-224.

Rodamilans, M.; Osaba, M. J. M.; To-F igueras, J.; Rivera Fillat, F.; Marque s, J. M.; Pérez, P.; Corbella, J.
(1988) Pb toxicity on endocrine testicular function in an occupationally exposed population. Hum. Toxicol.

7: 125-128.

Roelofs-Iverson, R. A.; Mulder, D. W.; Elveback, L. R.; Kurland, L. T.; Molgaard, C. A. (1984) ALS and heavy
metals: a pilot case study. Neurology 34: 393-395.
Roels, H.; Lauwerys, R. (1987) Evaluation of dose-effect and dose-response relationships for Pb exposure in different Belgian population groups (fetus, child, adult men and women). Trace Elem. Med. 4: 80-87.

Roels, H.; Hubermont, G.; Buchet, J.-P .; Lauwerys, R. (1978) Pl acental transfer of Pb, mercury, cadmium, and
carbon monoxide in women. III. Factors influencing the accumulation of heavy me tals in the placenta and the relationship between metal concentration in the placenta and in maternal and cord blood. Environ. Res.

16: 236-247. Roels, H. A.; Balis-Jacques, M. N.; Bu chet, J.-P.; Lauwerys, R. R. (1979) The influence of sex and of chelation therapy on erythrocyte protoporphyrin and urinary δ -aminolevulinic acid in Pb-exposed workers. J. Occup.

Med. 21: 527-539.
Roels, H. A.; Lauwerys, R. R.; Buchet, J. P.; Bernard, A. M.; Vos, A.; Overstey ns, M. (1989) Health significance of cadmium induced renal dysfunction: a five yr follow up. Br. J. Ind. Med. 46: 755-764.
Roels, H.; Lauwerys, R. ; Konings, J.; Buchet, J.-P.; Bernard, A.; Gr een, S.; Bradley, D.; Morgan, W.; Chettle, D.
(1994) Renal function and hyperfiltration capacity in Pb smelter workers with high bone Pb. Occup.

Environ. Med. 51: 505-512.
Roels, H.; Konings, J.; Green, S.; Br adley, D.; Chettle, D.; Lauwerys, R. (1995) Time-integrated blood Pb concentration is a valid surrogate for estimating the cu mulative Pb dose assessed by tibial Pb measurement.

Environ. Res. 69: 75-82.
Roels, H. A.; Van Assche, F. J.; Oversteyns, M.; De Groof, M.; Lauwerys, R. R.; Lison, D. (1997) Reversibility of microproteinuria in cadmium workers with incipient tubular dysfunction after reduction of exposure. Am.

J. Ind. Med. 31: 645-652.
Rogan, W. J.; Ware, J. H. (2003) Exposure to Pb in children

― how low is low enough? N. Engl. J. Med.

348: 1515-1516. Rogan, W. J.; Dietrich, K. N.; Ware, J. H.; et al. (2 001) The effect of chelation therapy with succimer on
neuropsychological development in children exposed to Pb. New Engl. J. Med. 344: 1421-1426. Rom, W. N. (1976) Effects of Pb on the female and reproduction: a review. Mt. Sinai J. Med. 43: 542-552.
Romeo, R.; Aprea, C.; Boccalon, P.; Orsi . D; Porcelli, B.; Sartorelli, P. (199 6) Serum erthropoie tin and blood Pb

concentrations. Int. Arch. Occu p. Environ. Health 69: 73-75. Ronis, M. J. J.; Badger, T. M.; Shema, S. J.; Roberson, P. K.; Shaikh, F. (1996) Reproductive toxicity and
growth effects in rats exposed to Pb at different periods during development. Toxicol. Appl. Pharmacol.

136: 361-371. Rose, G.; Day, S. (1990) The population mean predicts the number of deviant individuals. Br. Med. J. 301:

1031-1034. Rosen, J. F.; Chesney, R. W.; Hamstra, A.; DeLuca, H. F.; Mahaffey, K. R. (1980) Reduction in 1,25- dihydroxyvitamin D in children with increased Pb absorption. N. Engl. J. Med. 302: 1128-1131.
Rosenthal, R. (1984) Meta-analytic procedures for so cial research. Beverly Hills, CA: Sage Publications.

Roses, O. E.; Alvarez, S.; Conti, M. I.; Nobile, R. A.; Villaamil, E. C. (19 89) Correlation between Pb and prolactin
in males exposed and unexposed to Pb in Buenos Aires (Argentina) area. Bull. Environ. Contam. Toxicol.

42: 438-442.

# AX6-287 Rossner, P.; Boffetta, P.; Ceppi, M.; Bonassi, S.; Smerhovsky, Z.; Landa, K.; Juzova, D.; Šrám, R. J. (2005)

Chromosomal aberrations in lymphocytes of healthy subjects and risk of cancer. Environ. Health Perspect.

113: 517-520. Rothenberg, S. J.; Rothenberg, J. C. (2005) Testing the dose-response specification in epidemiology: public health
and policy consequences for Pb. Environ. Health Perspect. 113: 1190-1195. Rothenberg, S. J.; Schnaas, L.; Cansino- Ortiz, S.; Perroni-Hernández, E.; de la Torre, P.; Neri-Méndez, C.; Ortega,
P.; Hidalgo-Loperena, H.; Svendsgaard, D. (1989) Neurobehavioral deficits after low level Pb exposure in
neonates: the Mexico City pilot study. Neurotoxicol. Teratol. 11: 85-93. Rothenberg, S. J.; Karchmer, S.; Schnaas, L.; Perroni, E.; Zea, F.; Alba, J. F. (1994) Changes in serial blood Pb
levels during pregnancy. Environ. Health Perspect. 102: 876-880.
Rothenberg, S. J.; Manalo, M.; Jiang, J.; Cuellar, R.; Re yes, S.; Sanchez, M.; Diaz, M.; Khan, F.; Aguilar, A.; Reynoso, B.; Juaregui, M.; Acosta, S.; Johnson, C. (1999) Blood Pb level and blood pressure during
pregnancy in south central Los Angeles. Arch. Environ. Health 54: 382-389. Rothenberg, S. J.; Khan, F.; Manalo, M.; Jian, J.; Cuella r, R.; Reyes, S.; Acosta, S.; Jauregui, M.; Diaz, M.;
Sanchez, M.; Todd, A. C.; Johnson, C. (2000) Maternal bone Pb contribution to blood Pb during and after
pregnancy. Environ. Res. 82: 81-90. Rothenberg, S. J.; Kondrashov, V.; Manalo , M.; Jiang, J.; Cuellar, R.; Garcia, M.; Reynoso, B.; Reyes, S.; Diaz, M.;
Todd, A. C. (2002a) Increases in hypertension and blood pressure during pregnancy with increased bone Pb
levels. Am. J. Epidemiol. 156: 1079-1087. Rothenberg, S. J.; Schnaas, L.; Salgado- Valladares, M.; Casanueva, E.; Geller, A. M.; Hudnell, H. K.; Fox, D. A.
(2002b) Increased ERG a- and b-wave amplitudes in 7- to 10-yr-old children resulting from prenatal Pb
exposure. Invest. Ophthalmol. Vis. Sci. 43: 2036-2044.

Rowe, J. W.; Andres, R.; Tobin, J. D.; Norris, A. H.; Sh ock, N. W. (1976) Age-adju sted standards for creatinine

clearance. Ann. Intern . Med. 84: 567-569.
Rowland, A.; Wilcox, A. (1987) Maternal blood Pb [letter]. J. Epidemiol. Community Health 41: 184. Ruff, H. A.; Bijur P. E.; Markowitz, M.; Ma, Y.-C.; Rosen, J. F. (1993) Declining blood Pb levels and cognitive
changes in moderately Pb-poisoned children. JAMA J. Am. Med. Assoc. 269: 1641-1646.
Saenger, P.; Markowitz, M. E; Rosen, J. F. (1984) Depressed excretion of 6Beta-hydroxycortisol in Pb-toxic

children. J. Clin. Endocrinol. Metab. 58: 363-367.

Sakai, T.; Morita, Y.; Araki, T.; Kano, M. ; Yoshida, T. (2000) Relationship between δ -aminolevulinic acid
dehydratase genotypes and heme precursors in Pb workers. Am. J. Ind. Med. 38: 355-360. Salkever, D. S. (1995) Updated estimates of earnings benefits from reduced exposure of children to environmental

Pb. Environ. Res. 70: 1-6.

Sallmén, M.; Lindbohm, M.-L.; Anttila, A.; Taskinen, H.; Hemminki, K. (1992) Paternal occupational Pb exposure
and congenital malformations. J. Epidemiol. Community Health 45: 519-522.
Sallmén, M.; Anttila, A.; Lindbohm, M.-L.; Kyyrönen, P.; Taskinen, H.; Hemminki, K. (1995) Time to pregnancy among women occupationally exposed to Pb. J. Occup. Environ. Med. 37: 931-934.

Sallmén, M.; Lindbohm, M. L.; Anttila , A.; Taskinen, H.; Hemminki, K. (2000a) Time to pregnancy among the
wives of men occupationally exposed to Pb. Epidemiology 11: 141-147.
Sallmén, M.; Lindbohm, M. L.; Nurminen, M. (2000b) Pa ternal exposure to Pb and infertility. Epidemiology

11: 148-152. Sánchez-Fructuoso, A. I.; Torralbo, A.; Arroyo, M.; Lu que, M.; Ruilope, L. M.; Sant os, J. L.; Cruceyra, A.;
Barrientos, A. (1996) Occult Pb in toxication as a cause of hypertension and renal failure. Nephrol. Dial.
Transplant. 11: 1775-1780.

Sanín, L. H.; González-Cossío, T.; Romieu, I.; Peterson, K. E.; Ruíz, S.; Palazuelos, E.; Hernández-Avila, M.; Hu, H. (2001) Effect of maternal Pb burden on infant weight and weight gain at one mo of age among breastfed

infants. Pediatrics 107: 1016-1023.
Sankila, R.; Karjalainen, S.; Pukkala, E.; Oksanen, H.; Ha kulinen, T.; Teppo, L.; Hakama, M. (1990) Cancer risk among glass factory workers: an excess of lung cancer? Br. J. Ind. Med. 47: 815-818.
Sarasua, S. M.; Vogt, R. F.; Henderson, L. O.; Jones, P. A.; Lybarger, J. A. (2000) Serum immunoglobulins and
lymphocyte subset distributions in children and adu lts living in communities assessed for Pb and cadmium exposure. J. Toxicol. Environ. Health A. 60(1): 1-15.
Sarasua, S. M.; Mueller, P.; Kathman, S.; Campagna, D.; Uddin, M. S.; White, M. C. (2003) Confirming the utility of four kidney biomarker tests in a longitudinal follow-up study. Renal Failure 25: 797-817.

# AX6-288 Sargent, J. D.; Dalton, M. A.; O'Connor, G. T.; Olmst ead, E. M.; Klein, R. Z. (1999) Randomized trial of
calcium glycerophosphate-supplemented infant formula to prevent Pb absorption. Am. J. Clin.

Nutr. 69: 1224-1230. Sarto, F.; Stella, M.; Acqua, A. (1978) Cytogenetic study of a group of workers with increased Pb absorption

indices. Med. Lav. 69: 172-180. Sata, F.; Araki, S.; Sakai, T.; Nakata, A.; Yamashita, K.; Morita, Y.; Tanigawa, T.; Miki, A. (1997) Immunological
effects of CaEDTA injection: observations in two Pb workers. Am. J. Ind. Med. 32: 674-680.
Sata, F.; Araki, S.; Tanigawa, T.; Morita, Y.; Sakurai, S.; Nakata, A.; Katsuno, N. (1998) Changes in T cell subpopulations in Pb workers. Environ. Res. 76: 61-64.
Satarug, S.; Nishijo, M.; Ujjin, P.; Vanavanitkun, Y.; Bake r, J. R.; Moore, M. R. (2004) Evidence for concurrent
effects of exposure to environmental cadmium and Pb on hepatic CYP2A6 phenotype and renal function biomarkers in nonsmokers. Environ. Health Perspect. 112: 1512-1518.
Satz, P. (1993) Brain reserve capacity on symptom onset after brain injury: a formulation and review of evidence for threshold theory. Neuropsychology 7: 273-295.
Savitz, D. A.; Whelan, E. A.; Rowland, A. S.; Kleckner, R. C. (1990) Maternal employment and reproductive risk
factors. Am. J. Epidemiol. 132: 933-945. Schafer, T. E.; Adair, S. M. (2000) Prevention of dental disease. The role of the pediatrician. Pediatr. Clin. North

Am. 47: 1021-1042. Schantz, S. L. (1996) Developmental neurotoxicity of PCBs in humans: what do we know and where do we go from

here? Neurotoxicol. Teratol. 18: 217-227.

Schärer, K.; Veits, G.; Brockhaus, A.; Ew ers, U. (1991) High Pb content of deciduous teeth in chronic renal failure.
Pediatr. Nephrol. 5: 704-707. Schaumberg, D. A.; Mendes, F.; Balaram, M.; Dana, M. R. ; Sparrow, D.; Hu, H. (2004) Accumulated Pb exposure
and risk of age-related cataract in men. JAMA J. Am. Med. Assoc. 292: 2750-2754.
Schmid, E.; Bauchinger, M.; Pietruck, S.; Hall, G. (1972) Die cytogenetische Wirkung von Blei in menschlichen peripheren Lymphocyten in vitro und in vivo [The cytogeneticeffect of Pb in human peripehral
lymphocytes in vitro and in vivo]. Mutat. Res. 16: 401-406.
Schnaas, L.; Rothenberg, S. J.; Perroni, E.; Martínez, S.; Hernández, C.; Hernández, R. M. (2000) Temporal pattern in the effect of postnatal blood Pb level on intellectual development of young children. Neurotoxicol.

Teratol. 22: 805-810.
Schnaas, L.; Rothenberg, S. J.; Flores, M.-F.; Martinez, S.; Hernandez, C.; Os orio, E.; Velasco, S. R.; Perroni, E. (2006) Reduced intellectual development in children with prenatal Pb exposure. Environ. Health Perspect.

114: 791-797. Schober, S. E.; Mirel, L. B.; Graubard, B. I.; Brody, D. J.; Flegal, K. M. (2006) Blood Pb levels and death from all

causes, cardiovascular disease, and cancer: results from the NHANES III Mortality Study. Environ. Health
Perspect: doi:10.1289/ehp.9123 [6 July, 2006] Schroeder, S. R.; Hawk, B. (1987) Psycho-social factors, Pb exposure, and IQ. In: Schroeder, S. R., ed. Toxic
substances and mental retardation: neurobehavioral toxicology and teratology. Washington, DC: American
Association on Mental Deficiency; pp . 97-137. (Begab, M. J., ed. Monogr aphs of the American Association on Mental Deficiency: no. 8).
Schuhmacher, M.; Patemain, J. L.; Domingo, J. L.; Corb ella, J. (1997) An assessment of some biomonitors
indicative of occupational exposure to Pb. Trace Elem. Electrolytes 14(3): 145-149. Schumacher, C.; Brodkin, C. A.; Alexander, B.; Cullen, M.; Rainey, P. M.; van Netten, C.; Faustman, E.;
Checkoway, H. (1998) Thyroid function in Pb smelter workers: absence of subacute or cumulative effects
with moderate Pb burdens. Int. Arch. Occup. Environ. Health 71: 453-458. Schwanitz, G.; Lehnert, G.; Gebhart, E. (1970) Chromosomenschaden bei beruflicher Bleibelastung [Chromosome
damage after occupational exposure to Pb]. Dtsch. Med. Wochenschr. 95: 1636-1641.

Schwanitz, G.; Gebhart, E.; Rott, H.-D.; Schaller, K.-H .; Essing, H.-G.; Lauer, O.; Prestele, H. (1975) Chromosomenuntersuchungen bei Personen mit beruflic her Bleiexposition [Chromosome investigations in
subjects with occupational Pb exposure]. Dtsch. Med. Wochenschr. 100: 1007-1011.
Schwartz, J. (1985) Evidence for a blood Pb-blood pres sure relationship [memorandum to the Clean Air Science Advisory Committee]. Washington, DC: U.S. Environmental Protection Agency, Office of Policy Analysis.
Available for inspection at: U.S. Environmental Protection Agency, Central Docket Section, Washington,

DC; docket no. ECAO-CD-81-2 IIA.F.60.
Schwartz, J. (1991) Pb, blood pressure, and cardiovascular disease in men and women. Environ. Health Perspect. 91:

71-75.

# AX6-289 Schwartz, J. (1994) Low-leve l Pb exposure and children's IQ: a meta-analy sis and search for a threshold. Environ.

Res. 65: 42-55. Schwartz, J. (1995) Pb, blood pressure, and cardiovascular disease in men. Arch. Environ. Health 50: 31-37.
Schwartz, J.; Otto, D. (1987) Blood Pb, hearing thresholds, and neurobehavioral development in children and youth.

Arch. Environ. Health 42: 153-160. Schwartz, J.; Otto, D. (1991) Pb and minor hearing impairment. Arch. Environ. Health 46: 300-305.
Schwartz, J.; Angle, C.; Pitcher, H. (1986) Relationship between childhood blood Pb and stature. Pediatrics

77: 281-288. Schwartz, J.; Landrigan, P. J.; Baker, E. L., Jr.; Orenstein, W. A.; von Lindern, I. H. (1990) Pb-induced anemia:
dose-response relationships and evidence for a threshold. Am. J. Public. Health 80: 165-168.

Schwartz, B. S.; Bolla, K. I.; Stew art, W.; Ford, D. P.; Agnew, J.; Frumkin, H. (1993 ) Decrements in neurobehavioral performance associated with mixed exposure to organic and inorganic Pb. Am. J.
Epidemiol. 137: 1006-1021.

Schwartz, B. S.; Lee, B.-K.; Stewart, W.; Sithisar ankul, P.; Strickland, P. T.; Ahn, K.-D.; Kelsey, K. (1997) δ

Aminolevulinic acid dehydratase genotype modifies four hour urinary Pb excretion after oral
administration of dimercaptosuccinic acid. Occup. Environ. Med. 54: 241-246.

Schwartz, B. S.; Stewart, W. F.; Kelsey, K. T.; Simon, D.; Park, S.; Li nks, J. M.; Todd, A. C. (2000a) Associations
of tibial Pb levels with BsmI polym orphisms in the vitamin D receptor in former organolead manufacturing
workers. Environ. Health Perspect. 108: 199-203.

Schwartz, B. S.; Stewart, W. F.; Bolla, K. I.; Simon, M. S.; Bandeen-R oche, K.; Gordon, B.; Links, J. M.; Todd, A.
C. (2000b) Past adult Pb exposure is associated w ith longitudinal decline in cognitive function. Neurology

55: 1144-1150.

Schwartz, B. S.; Stewart, W. F.; Todd, A. C.; Simon, D.; Links, J. M. (2000c) Different associations of blood Pb,
meso 2,3-dimercaptosuccinic acid (DMS A)-chelatable Pb, and tibial Pb leve ls with blood pressure in 543
former organolead manufacturing workers. Arch. Environ. Health. 55: 85-92.

Schwartz, B. S.; Lee, B.-K.; Lee, G.-S.; Stewart, W. F.; Simon, D.; Kelsey, K.; Todd, A. C. (2000d) Associations of
blood Pb, dimercaptosuccinic acid-ch elatable Pb, and tibia Pb with polymorphisms in the vitamin D
receptor and δ -aminolevulinic acid dehydratase genes. Environ. Health Perspect. 108: 949-954.

Schwartz, B. S.; Lee, B. K.; Lee, G. S.; Stewart, W. F.; Lee, S. S.; Hwang, K. Y.; Ahn, K.-D.; Kim, Y.-B.; Bolla,
K. I.; Simon, D.; Parsons, P. J.; Todd, A. C. (2001a) Associations of blood Pb, dimercaptosuccinic acidchelatable Pb, and tibia Pb with neurobehavioral test sc ores in South Korean Pb workers. Am. J. Epidemiol.

153: 453-464.

Schwartz, B. S.; Stewart, W. F.; Bolla, K. I.; Simon, P. D.; Bandeen-Roche, K.; Gordon, P. B.; Links, J. M.; Todd, A. C. (2001b) Past adult Pb exposure is associated with longitudinal decline in cognitive function (erratum
to Neurology 55: 1144-1150). Neurology 56: 283.
Schwartz, B. S.; Stewart, W.; Hu, H. (2002) Neurobehavi oural testing in workers occupationally exposed to Pb [letter]. Occup. Environ. Med. 59: 648-649.

Schwartz, B. S.; Lee, B.-K.; Bandeen-Roche, K.; Stewart, W.; Bolla, K. I. ; Links, J.; et al. (2005) Occupational Pb
exposure and longitudinal decline in neurobehavioral test scores. Epidemiology 16: 106-113.

Sciarillo, W. G.; Alexander, G.; Farrell, K. P. (1992) Pb exposure and child behavior. Am. J. Public Health

82: 1356-1360. Seeber, A.; Meyer-Baron, M.; Schäper, M. (2002) A summary of two meta-analyses on neurobehavioural effects due to occupational Pb exposure. Arch. Toxicol. 76: 137-145.
Selander, S.; Cramér, K. (1970) Interrelationships between Pb in blood, Pb in urine, and ALA in urine during Pb

work. Br. J. Ind. Med. 27: 28-39. Selevan, S. G.; Landrigan, P. J.; Stern, F. B.; Jones, J. H. (1985) Mortality of Pb smelter workers. Am. J. Epidemiol.

122: 673-683. Selevan, S. G.; Rice, D. C.; Hogan, K. A.; Euling, S. Y.; Pfahles-Hutc hens, A.; Bethel, J. (2003) Blood Pb concentration and delayed puberty in girls. N. Engl. J. Med. 348: 1527-1536.
Shadick, N. A.; Kim, R.; Weiss, S.; Liang, M. H.; Sparro w, D.; Hu, H. (2000) Effect of low level Pb exposure
on hyperuricemia and gout among middle aged and elderly men: the normative aging study. J. Rheumatol.

27: 1708-1712. Sharp, D. S.; Benowitz, N. L.; Osterloh , J. D.; Becker, C. E.; Smith, A. H.; Sy me, S. L. (1990) Influence of race, tobacco use, and caffeine use on the relation between blood pressure and blood Pb concentration. Am. J.
Epidemiol. 131: 845-854.

# AX6-290 Sheffet, A.; Thind, I.; Miller, A. M.; Louria, D. B. (1982) Cancer mortality in a pigment plant utilizing Pb and zinc

chromates. Arch. Environ. Health 37: 44-52. Shen, X.-M.; Yan, C.-H.; Guo, D.; Wu, S.-M.; Li, R.-Q.; Huang, H.; Ao, L.-M.; Zhou, J.-D.; Hong, Z.-Y.; Xu, J.-D.;
Jin, X.-M.; Tang, J.-M. (1998) Low-level prenatal Pb exposure and neurobehavioral development of
children in the first yr of life: a prospective study in Shanghai. Environ. Res. 79: 1-8.

Shen, X.-M.; Wu, S.-H.; Yan, C.-H.; Zhao, W.; Ao, L.-M.; Zhang, Y.-W.; He, J.-M.; Ying, J.-M.; Li, R.-Q.; Wu,
S.-M.; Guo, D. (2001) Delta-aminolevulinate dehydratase polymorphism and blood Pb levels in Chinese

children. Environ. Res. 85: 185-190. Sherins, R. J. (1995) Are semen quality and male fertility changing? N. Engl. J. Med. 332: 327-328.
Shiau, C.-Y.; Wang, J.-D.; Chen, P.-C. (2004) Decreased fecundity among male Pb workers. Occup. Environ. Med.

61: 915-923. Shukla, H.; Atakent, Y. S.; Ferrara, A.; Topsis, J.; Antoine, C. (1987) Postnatal overesti mation of gestational age in
preterm infants. Am. J. Dis. Child. 141: 1106-1107. Shukla, R.; Bornschein, R. L.; Dietrich, K. N.; Buncher, C. R.; Berger, O. G.; Hammond, P. B.; Succop, P. A.
(1989) Fetal and infant Pb exposure: effects on growth in stature. Pediatrics 84: 604-612.
Shukla, V. K.; Prakash, A.; Tripathi, B. D.; Reddy, D. C.; Singh, S. (1998) Biliary heavy metal concentrations in carcinoma of the gall bladder: case-control study. Br. Med. J. 317: 1288-1289.
Siegel, M.; Forsyth, B.; Siegel, L.; Cullen, M. R. (1989) The effect of Pb on thyroid function in children. Environ.

Res. 49: 190-196. Siemiatycki, J.; Gérin, M.; Stewart, P.; Nadon, L.; Dewar, R.; Richardson, L. (1988) Associations between several
sites of cancer and ten types of exhaust and combustion products: results from a case-referent study in

Montreal. Scand. J. Work Environ. Health 14: 79-90. Siemiatycki, J.; Gérin, M.; Dewar, R.; Nadon, L.; Lakhan i, R.; Bégin, D.; Richardson, L. (1991) Associations
between occupational circumstances and cancer. In: Siemiatycki, J., ed. Risk f actors for cancer in the
workplace. Boca Raton, FL: CRC Press; pp. 141-145. Silbergeld, E. K. (1991) Pb in bone: implications for toxicology during pregnancy and lactation. Environ. Health
Perspect. 91: 63-70. Silbergeld, E. K.; Sauk, J.; Somerman, M.; Todd, A.; McNeill, F.; Fowler, B.; Fontaine, A. ; van Buren, J. (1993) Pb in bone: storage site, exposure source, and target organ. Presented at: Ninth international neurotoxicology
conference; October 1991; Little Rock, AR. Neurotoxicology 14(2-3): 225-236.
Silbergeld, E. K.; Waalkes, M.; Rice, J. M. (2000) Pb as a carcinogen: experi mental evidence and mechanisms of

action. Am. J. Ind. Med. 38: 316-323.
Silva, P. A.; Hughes, P.; Williams, S.; Faed, J. M. (1988) Blood Pb, intelligence, reading attainment, and behaviour in eleven yr old children in Dunedin, New Zealand. J. Child Psychol. Psychiatr. Allied Discipl. 29: 43-52.
Singh, B.; Chandran, V.; Bandhu, H. K.; Mittal, B. R.; Bhattacharya, A.; Jindal, S. K.; Varma, S. (2000) Impact of
Pb exposure on pituitary-thyroid axis in humans. BioMetals 13: 187-192. Smith, F. L., 2nd; Rathmell, T. K.; Marcil, G. E. (1938) The early diagnosis of acute and latent plumbism. Am. J.

Clin. Pathol. 8: 471-508.
Smith, C. M.; Wang, X.; Hu, H.; Kelsey, K. T. (1995) A polymorphism in the δ -aminolevulinic acid dehydratase gene may modify the pharmacokinetics and toxicity of Pb. Environ. Health Perspect. 103: 248-253.
Sokas, R. K.; Simmens, S.; Sophar, K.; Welch, L. S.; Li ziewski, T. (1997) Pb levels in Maryland construction

workers. Am. J. Ind. Med. 31: 188-194.
Sokol, R. Z. (1987) Hormonal effects of Pb acetate in the male rat: mechanism of action. Biol. Reprod.

37: 1135-1138. Sokol, R. Z.; Berman, N.; Okuda, H.; Raum, W. (1998) Effects of Pb exposure on GnRH and LH secretion in male rats: response to castration and ά -methyl- p -tyrosine (AMPT) challenge. Reprod. Toxicol. 12: 347-355.
Sokol, R. Z.; Wang, S.; Wan, Y.-J. Y.; Stanczyk, F. Z.; Gentzschein, E.; Chap in, R. E. (2002) Long-term, low-dose
Pb exposure alters the gonadotropin-releasing hormone system int he male rat. Environ. Health Perspect.

110: 871-874.

Soldin, O. P.; Pezzullo, J. C.; Hanak, B. ; Miller, M.; Soldin, S. J. (2003) Changing trends in the epidemiology of
pediatric Pb exposure: interrelationship of blood Pb and ZPP concentrations and a comparison to the US population. Ther. Drug Monit. 25: 415-420.
Solliway, B. M.; Schaffer, A.; Pratt, H. ; Yannai, S. (1996) Effect s of exposure to Pb on selected biochemical and haematological variables. PharmacoI. ToxicoI. 78: 18-22.

# AX6-291 Sönmez, F.; Dönmez, O.; Sönmez, H. M.; Keskino ĝ lu, A.; Kabasakal, C.; Mir, S. (2002) Pb exposure and urinary Nacetyl β D glucosaminidase activity in adolescent workers in auto repair workshops. J. Adolesc. Health 30:

213-216. Sorel, J. E.; Heiss, G.; Tyroler, H. A. ; Davis, W. B.; Wing, S. B.; Ragland, D. R. (1991) Black-white differences
in blood pressure among participants in NHANES II: the contribution of blood Pb. Epidemiology 2:

348-352. Sorrell, M.; Rosen, J. F.; Roginsky, M. (1977) Interactions of Pb, calcium, vitamin D, and nutrition in Pb-burdened

children. Arch. Environ. Health 32: 160-164.

Sowers, M.; Jannausch, M.; Scholl, T.; Li, W.; Kemp, F. W.; Bogden, J. D. (2002) Blood Pb concentrations and
pregnancy outcomes. Arch. Environ. Health 57: 489-495.
Spencer, H.; O'Sullivan, V.; Sontag, S. J. (1992) Does Pb play a role in Paget's disease of bone? A hypothesis. J.

Lab. Clin. Med. 120: 798-800.
Spencer, H.; O'Sullivan, V.; Sontag, S. J. (1994) Occupatio nal exposure to Pb: preliminary observations in Paget's disease of bone in women and in family members of af fected patients. J. Trace El em. Exp. Med. 7: 53-58.
Spencer, H.; O'Sullivan, V.; Sontag, S. J. (1995) Exposure to Pb, a potentially hazardous toxin: Paget's disease of
bone. J. Trace Elem. Exp. Med. 8: 163-171. Spinnato, J. A.; Sibai, B. M.; Shaver, D. C.; Anderson, G. D. (1984) Inaccuracy of Dubo witz gestational age in low
birth weight infants. Obstet. Gynecol. (Hagerstown, MD, U.S.) 63: 491-495.
Spivey, G. H.; Baloh, R. W.; Brown, C. P.; Browdy, B. L.; Campion, D. S.; Valentine, J. L.; Morgan, D. E.; Culver, B. D. (1980) Subclinical effects of chronic increased Pb absorption--a prospective study. III. Neurologic
findings at follow-up examination. J. Occup. Med. 22: 607-612.
Spreen, O.; Risser, A. T.; Edgell, D. (1995) Developmen tal neuropsychology. New York, NY: Oxford University

Press.

Staessen, J.; Yeoman, W. B.; Fletcher, A. E.; Markowe, H. L.; Marmot, M. G.; Rose, G.; Semmence, A.; Shipley,
M. J.; Bulpitt, C. J. (1990) Blood Pb concentration, renal function, and blood pressure in London civil

servants. Br. J. Ind. Med. 47: 442-447.
Staessen, J. A.; Lauwerys, R. R.; Buch et, J.-P.; Bulpitt, C. J.; Rondia, D.; Van Renterghem, Y.; Amery, A. (1992)
Impairment of renal function with increasing blood Pb co ncentrations in the general population. N. Engl. J.

Med. 327: 151-156.
Staessen, J. A.; Dolenc, P.; Amery, A.; Buchet, J.-P.; Cl aeys, F.; Fagard, R.; Lauwerys , R.; Lijnen, P.; Roels, H.;
Rondia, D.; Sartor, F.; Thijs, L.; Vyncke, G., on behalf of the Cadmibel Study Group. (1993) Environmental Pb exposure does not increase blood pressure in the population: evidence from the
Cadmibel study. J. Hypertens. 11(suppl. 2): S35-S41. Staessen, J. A.; Bulpitt, C. J.; Fagard, R.; Lauwerys, R. R.; Roels, H.; Thijs, L.; Amer y, A. (1994) Hypertension
caused by low-level Pb exposure: myth or fact? J. Cardiovasc. Risk 1: 87-97.
Staessen, J. A.; Roels, H.; Fagard, R. (1996a) Pb e xposure and conventional and ambulatory blood pressure: a prospective population study. JAMA J. Am. Med. Assoc. 275: 1563-1570.
Staessen, J. A.; Buchet, J.-P.; Ginucchio, G.; Lauwerys, R. R.; Lijnen, P.; Roels, H.; Fagard, R. (1996b) Public
health implications of environmental exposure to ca dmium and Pb: an overview of epidemiological studies in Belgium. J. Cardiovasc. Risk 3: 26-41.
Staessen, J. A.; Nawrot, T.; Den Hond, E.; Thijs, L.; Fagard, R.; Hoppenbrouwers, K.; Koppen, G.; Nelen, V.;

Schoeters, G.; Vanderschueren, D.; Van Hecke, E.; Verschaeve, L.; Vlietinck, R.; Roels, H. A. (2001) Renal function, cytogenetic measurements, and sexual developments in adolescents in relation to
environmental pollutants: a feasibility study of biomarkers. Lancet 357: 1660-1669.
Steenland, K.; Boffetta, P. (2000) Pb and cancer in humans: where are we now? Am. J. Ind. Med. 38: 295-299. Steenland, K.; Thun, M. J.; Ferguson, C. W.; Port, F. K. (1990) Occupational and other exposures associated with
male end-stage renal disease: a case/contro l study. Am. J. Public Health. 80: 153-157.
Steenland, K.; Selevan, S.; Landrigan, P. (1992) The mort ality of Pb smelter workers: an update. Am. J. Public

Health 82: 1641-1644.
Steenland, K.; Loomis, D.; Shy, C.; Simonsen, N. (1996) Review of occupational lung carcinogens. Am. J. Ind.

Med. 29: 474-490. Steenland, K.; Mannetje, A.; Boffetta, P.; Stayner, L.; A ttfield, M.; Chen, J.; Dosemeci, M.; DeKlerk, N.; Hnizdo,
E.; Koskela, R.; Checkoway, H. (2002) Pooled exposure-response analyses and risk assessmen for lung cancer in 10 cohorts of silica-exposed workers: an IA RC multi-centric study (vol 12, pg 773, 2001). Cancer

Causes Control 13: 777.
Stevens, L. A.; Levey, A. S. (2005a) Measurement of kidney function. Med. Clin. N. Am. 89: 457-473.

# AX6-292 Stevens, L. A.; Levey, A. S. (2005b) Chronic kidney disease in the elderly

― how to assess risk. N. Engl. J. Med.

352: 2122-2124.

Stewart, W. F.; Schwartz, B. S.; Simon, D.; Bolla, K. I.; Todd, A. C.; Links, J. (1999) Neurobehavioral function and
tibial and chelatable Pb levels in 543 former organolead workers. Neurology 52: 1610-1617.
Stewart, W. F.; Schwartz, B. S.; Simon, D.; Kelsey, K.; Todd, A. C. (2002) ApoE genotype, past adult Pb exposure, and neurobehavioral function. Environ. Health Perspect. 110: 501-505.
Stiles, K. M.; Bellinger, D. C. (1993) Neuropsychological correlates of low-level Pb exposure in school-age
children: a prospective study. Neurotoxicol. Teratol. 15: 27-35. Stollery, B. T. (1996) Reaction time changes in worker s exposed to Pb. Neurotoxicol. Teratol. 18: 477-483.
Stollery, B. T.; Broadbent, D. E.; Ba nks, H. A.; Lee, W. R. (1991) Short term prospective study of cognitive
functioning in Pb workers. Br. J. Ind. Med. 48: 739-749. Sugawara, E.; Nakamura, K.; Miyake, T.; Fukumura, A.; Se ki, Y. (1991) Lipid peroxidation and concentration of
glutathione in erythrocytes from workers exposed to Pb. Br. J. Ind. Med. 48: 239-242.

Sun, L.; Hu, J.; Zhao, Z.; Li, L.; Ch eng, H. (2003) Influence of exposure to environmental Pb on serum
immunoglobulin in preschool children. Environ. Res. 92: 124-128.
Süzen, H. S.; Duydu, Y.; Aydin, A.; I ş imer, A; Vural, N. (2003) Influence of the delta-aminolevulinic acid dehydratase (ALAD) polymorphism on biomarkers of Pb exposure in Turkish storage battery
manufacturing workers. Am. J. Ind. Med. 43: 165-171.
Tabacova, S.; Balabaeva, L. (1993) Environmental pollutants in relation to complications of pregnancy. Environ. Health Perspect. 101(suppl. 2): 27-31.
Tang, N.; Zhu, Z. Q. (2003) Adverse reproductive effects in fe male workers of Pb battery plants. Int. J. Occup. Med.

Environ. Health 16: 359-361. Taskinen, H. (1988) Spontaneous abortions among wome n occupationally exposed to Pb. In: Hogstedt, C.;
Reuterwall, C., eds. Progress in o ccupational epidemiology. New York, NY: Elsevier Science Publishers;
pp. 197-200.

Tassler, P.; Schwartz, B. S.; Coresh, J.; Stewart, W.; Todd, A. (2001) Associations of tibia Pb, DMSA-Chelatable
Pb, and blood Pb with measures of peripheral nervous system function in former organolead manufacturing

workers. Am. J. Ind. Med. 39: 254-261. Taupeau, C.; Poupon, J.; Treton, D.; Brosse, A.; Richard, Y.; Machelon, V. (2003) Pb reduces messenger RNA and
protein levels of cytochro me P450 aromatase and estrogen recepto r "Beta" in human ovarian granulosa
cells. Biol. Reprod. 68: 1982-1988.

Telišman, S.; Pizent, A.; Jurasovi ć , J.; Cvitkovi ć , P. (2004) Pb effect on blood pressure in moderately Pb-exposed

male workers. Am. J. Ind. Med. 45: 446-454. Téllez-Rojo, M. M.; Bellinger, D. C.; Arroyo-Quiroz, C.; Lamadrid-Figuero a, H.; Mercado-García, A.; SchnaasArrieta, L.; Wright, R. O.; Hernández-Avila, M.; Hu, H. (2006) Longitudinal associations between blood

Pb concentrations < 10 μ g/dL and neurobehavioral development in environmentally-exposed children in Mexico City. Pediatrics 118: e323-e330.
Tepper, A.; Mueller, C.; Singal, M.; Sa gar, K. (2001) Blood pressure, left ventricular mass, and Pb exposure in
battery manufacturing workers. Am. J. Ind. Med. 40: 63-72. Teruya, K.; Sakurai, H.; Omae, K.; Higashi, T.; Muto , T.; Kaneko, Y. (1991) E ffect of Pb on cardiac
parasympathetic function. Int. Arch. Occup. Environ. Health 62: 549-553.
Thacker, S. B.; Hoffman, D. A.; Smith, J.; Steinberg, K.; Zack, M. (1992) Effect of low-level body burdens of Pb on the mental development of children: limitations of meta-analysis in a review of longitudinal data. Arch.

Environ. Health 47: 336-346.
Thompson, S. G.; Pocock, S. J. (1992) Can meta-analyses be trusted? Lancet 338: 1127-1130. Thomson, G. O. B.; Raab, G. M.; Hepburn, W. S.; Hunter, R.; Fulton, M.; Laxen, D. P. H. (1989) Blood-Pb levels
and children's behaviour - results from the Edinburgh Pb study. J. Child Psychol. Psychiatr. 30: 515-528.
Todd, A. C.; Buchanan, R.; Carroll, S.; Moshier, E. L.; Pop ovac, D.; Slavkovich, V.; Graziano, J. H. (2001) Tibia Pb levels and methodological uncertainty in 12 -yr-old children. Environ. Res. 86: 60-65.
Tomatis, L. (1990) Cancer: causes, occurrence, and contro l. Lyon, France: International Agency for Research on
Cancer. (IARC scientific publications: v. 100). Tong, I. S.; Lu, Y. (2001) Identification of confounders in the assessment of the relationship between Pb exposure
and child development. Ann. Epidemiol. 11: 38-45. Tong, S.; Baghurst, P.; McMichael, A.; Sawyer, M.; Mudge, J. (1996) Lifetime exposure to environmental Pb and
children's intelligence at 11-13 yrs: the Port Pi rie cohort study. Br. Med. J. 312: 1569-1575.

# AX6-293 Tong, S.; Baghurst, P. A.; Sawyer, M. G. ; Burns, J.; McMichael, A. J. (1998) Declining blood Pb levels and changes
in cognitive function during childhood: the Port Pirie cohort study. JAMA J. Am. Med. Assoc. 280: 1915-

1919. Tong, S.; McMichael, A. J.; Baghurst, P. A. (2000) Interactions between environmental Pb exposure and
sociodemographic factors on cognitive development. Arch. Environ. Health 55: 330-335.

Torres-Sánchez, L. E.; Berkowitz, G.; López-Carrillo, L.; Torres-Arreola, L.; Ríos, C.; López-Cervantes, M. (1999)
Intrauterine Pb exposure and preterm birth. Environ. Res. 81: 297-301.
Trope, I.; Lopez-Villegas, D.; Lenkinsk i, R. E. (1998) Magnetic resonance imaging and spectroscopy of regional brain structure in a 10-yr-old boy with elevated blood Pb levels. Pediatrics 101(6): E7.
Trope, I.; Lopez-Villegas, D.; Cecil, K. M.; Lenkinski, R. E. (2001) Exposure to Pb appears to selectively alter
metabolism of cortical gray matter. Pediatrics 107: 1437-1443.

Tsai, S.-Y.; Chen, T.-F.; Chao, K.-Y. (2000) Subclinical neurobehavioral effect s of low-level Pb exposure in glaze
factory workers. Acta Neurol. Taiwan. 9: 122-127.

Tsaih, S.-W.; Korrick, S.; Schwartz, J. ; Amarasiriwardena, C.; Ar o, A.; Sparrow, D; Hu, H. (2004) Pb, diabetes,
hypertension, and renal function: the Normative Aging Study. Environ. Health Perspect. 112: 1178-1182.
Tuppurainen, M.; Wagar, G.; Kurppa, K.; Sakari, W.; Wambugu, A.; Froseth, B.; Alho, J.; Nykyri, E. (1988) Thyroid function as assessed by routine laboratory tests of workers with long-term Pb exposure. Scand. J.

Work Environ. Health 14: 175-180.
Tvinnereim, H. M.; Eide, R.; Riise, T. (2000) Heavy meta ls in human primary teeth: some factors influencing the

metal concentrations. Sci. Total Environ. 255: 21-27.
U.S. Environmental Protection Agency. (1986a) Air quality criteria for Pb. Research Triangle Park, NC: Office of

Health and Environmental Assessment, Environmental Criteria and Assessment Office; EPA report no. EPA-600/8-83/028aF-dF. 4v. Available from: NTIS, Springfield, VA; PB87-142378.
U.S. Environmental Protection Agency. (1986b) Pb effects on cardiovascular function, early development, and
stature: an addendum to U.S. EPA Air Quality Criteria for Pb (1986). In: Air quality criteria for Pb, v. 1. Research Triangle Park, NC: Office of Health and Environmental Assessment, Environmental Criteria and
Assessment Office; pp. A1-A67; EPA report no. EPA-600/8-83/028aF. Available from: NTIS, Springfield,

VA; PB87-142378. U.S. Environmental Protection Agency. (1990) Air qua lity criteria for Pb: supplement to the 1986 addendum.
Research Triangle Park, NC: Office of Health and Environmental Assessment, Environmental Criteria and
Assessment Office; report no. EPA/600/8-89/049F. Available from: NTIS, Springfield, VA; PB91-138420. U.S. Environmental Protection Agency. (2003) Evalua tion of the ICRP Pb Biokinetics Model: empirical
comparisons with observations of plasma-blood Pb concentration relationships in humans. Washington, DC: Office of Emergency and Remedial Response; FEDSIM order no. DABT; Syracuse Research
Corporation; contract no. GS-10F-0137K.
U.S. Environmental Protection Agency. (2004) Air quality criteria for particulate matter. Research Triangle Park,

NC: National Center for Environmental Assessment; re port no. EPA/600/P-99/002aF-bF. 2v. Available:
http://cfpub.epa.gov/ncea/ [9 November, 2004].
U.S. Environmental Protection Agency. (2005) Guidelines for carcinogen risk assessment. Washington, DC: Risk Assessment Forum; report no . EPA/630/P-03/001F. Available: http://cfpub.epa.g ov/ncea/index.cfm

[30 November, 2005].
U.S. Renal Data System. (2004) Outcomes: hospitalization & mortality. In: Annual data report. Minneapolis, MN: USRDS Coordinating Center; pp. 118-138. Available:
http://www.usrds.org/2004/pdf/06_hosp_morte_04.pdf [21 November, 2005]. Ündeger, U.; Ba ş aran, N.; Canpinar, H.; Kansu, E. (1996) Immune alterations in Pb-exposed workers. Toxicology

109: 167-172. Valciukas, J. A.; Lilis, R.; Eisinger, J. ; Blumberg, W. E.; Fischbein, A.; Selikof f, I. J. (1978) Behavioral indicators
of Pb neurotoxicity: results of a clinical field surv ey. Int. Arch. Occup. Environ. Health 41: 217-236. Valentine, J. L.; Baloh, R. W.; Browdy , B. L.; Gonick, H. C.; Brown, C. P.; Spivey, G. H.; Culver, B. D. (1982)
Subclinical effects of chronic increased Pb absorption--a prospective study. J. Occup. Med. 24: 120-125.
Valentino, M.; Governa, M.; Marchiseppe, I.; Visona, I. (1991) Effects of Pb on polymorphonuclear leukocyte (PMN) functions in occupationally exposed workers. Arch. Toxicol. 65: 685-688.
Van De Vyver, F. L.; D'Haese, P. C.; Visser, W. J.; Elsevi ers, M. M.; Knippenberg, L. J.; Lamberts, L. V.; Wedeen, R. P.; De Broe, M. E. (1988) Bone Pb in dialysis patients. Kidney Int. 33: 601-607.
Van Den Berg, B. J.; Oechsli, F. W. (1984) Prematurity. In: Bracken, M. B., ed. Perinatal epidemiology. New York,
NY: Oxford University Press; pp. 69-85.

# AX6-294 Van Larebeke, N.; Koppen, G.; Nelen, V.; Schoeters, G.; Van Loon H, Albe ring H, Riga L, Vlietinck, R.;
Kleinjans, J.; Flemish Environment and Health Study Group. (2004) Differences in HPRT mutant frequency among middle-aged Flemish women in association with area of residence and blood Pb levels.

Biomarkers 9: 71-84.
Verberk, M. M.; Willems, T. E. P.; Verplanke, A. J. W.; De Wolff, F. A. (1996) Envir onmental Pb and renal effects

in children. Arch. Environ. Health 51: 83-87.
Verschoor, M.; Wibowo, A.; Herber, R.; van Hemmen, J.; Zielhuis, R. (1987) Influence of occupational low-level
Pb exposure on renal parameters. Am. J. Ind. Med. 12: 341-351. Vig, E. K.; Hu, H. (2000) Pb toxicity in older adults. J. Am. Geriatr. Soc. 48: 1501-1506.
Vimpani, G. V.; Wigg, N. R.; Robertson, E. F.; McMichael, A. J.; Baghurst, P. A.; Roberts, R. J. (1985) The Port
Pirie cohort study: blood Pb concentration and childho od developmental assessment. In: Goldwater, L. J.; Wysocki, L. M.; Volpe, R. A., eds. Edited proceedings: Pb environmental health - the cu rrent issues; May;
Durham, NC. Durham, NC: Duke University; pp. 139-146. Vinceti, M.; Guidetti, D.; Bergomi, M. ; Caselgrandi, E.; Vivoli, R.; Olmi, M.; Rinaldi, L.; Rovesti, S.; Solimè, F.
(1997) Pb, cadmium, and selenium in the blood of patient s with sporadic amyotrophic lateral sclerosis. Ital.

J. Neurol. Sci. 18: 87-92. Vupputuri, S.; He, J.; Muntner, P.; Bazzan o, L. A.; Whelton, P. K.; Batuman, V. (2003) Blood Pb level is associated
with elevated blood pressure in blacks. Hypertension 41: 463-468.
Wagnerova, M.; Wagner, V.; Madlo, Z.; Zavazal, Y.; Wokounova, D.; Kriz, J.; Mohyla, O. (1986) Seasonal variations in the level of immunoglobulins and serum proteins of children differing by exposure to
air-borne Pb. J. Hyg. Epidemiol. Microbiol. Immunol. 30(2): 127-138.

Walkowiak, J.; Altmann, L.; Krämer, U.; Sveinsson, K.; Turfeld, M.; Weishoff-Hou ben, M.; Winneke, G. (1998) Cognitive and sensorimotor functions in 6-yr-old children in relation to Pb and mercury
levels: adjustment for intelligence and contrast sensitivity in computerized testing. Neurotoxicol. Teratol.

20: 511-521. Wang, C.-L.; Chuang, H.-Y.; Ho, C.-K .; Yang, C.-Y.; Tsai, J.-L.; Wu, T. -S.; Wu, T.-N. (2002a) Relationship
between blood Pb concentrations and learning ac hievement among primary school children in Taiwan.

Environ. Res. 89: 12-18. Wang, V.-S.; Lee, M.-T.; Chiou, J.-Y.; Guu, C.-F.; Wu, C.-C.; Wu, T.-N.; Lai, J.-S. (2002b) Relationship

between blood Pb levels and renal function in Pb battery workers. Int. Arch. Occup. Environ.

Health 75: 569-575. Ward, N. I.; Watson, R.; Bryce-Smith, D. (1987) Placental element levels in relation to fetal development for
obstetrically 'normal' births: a study of 37 elements. Evidence for effects of cadmium, Pb and zinc on fetal growth, and for smoking as a source of cadmium. Int. J. Biosoc. Res. 9: 63-81.

Wasserman, G.; Graziano, J. H.; Factor-Litvak, R.; Po povac, D.; Morina, N.; Musa begovic, A.; Vrenezi, N.;
Capuni-Paracka, S.; Lekic, V.; Preten i-Redjepi, E.; Hadzialjevic, S.; Sla vkovich, V.; Kline, J.; Shrout, P.; Stein, Z. (1992) Independent effects of Pb exposure and iron deficiency anemia on developmental outcome
at age 2 yrs. J. Pediatr. 121: 695-703.

Wasserman, G. A.; Graziano, J. H.; Factor-Litvak, P.; Po povac, D.; Morina, N.; Musabegovic, A.; Vrenezi, N.; Capuni-Paracka, S.; Lekic, V.; Preten i-Redjepi, E.; Hadzialjevic, S.; Sla vkovich, V.; Kline, J.; Shrout, P.;
Stein, Z. (1994) Consequences of Pb exposure and iron supplementation on childhood development at age
4 yrs. Neurotoxicol. Teratol. 16: 233-240.

Wasserman, G. A.; Liu, X.; Lolacono, N. J.; Factor-Litvak, P.; Kline, J. K.; Popovac, D.; Morina, N.; Musabegovic,
A.; Vrenezi, N.; Capuni-Paracka, S.; Lekic, V.; Pret eni-Redjepi, E.; Hadzialj evic, S.; Slavkovich, V.;
Graziano, J. H. (1997) Pb exposure and intelligence in 7-yr-old children: the Yugoslavia prospective study. Environ. Health Perspect. 105: 956-962.
Wasserman, G. A.; Staghezza-Jaramillo, B.; Shrout, P.; Popovac, D.; Graziano, J. (1998) The effect of Pb exposure
on behavior problems in preschool children. Am. J. Pub. Health 88 (3): 481-486. Wasserman, G. A.; Musabegovic, A.; Liu, X.; Kline, J. ; Factor-Litvak, P.; Grazian o, J. H. (2000a) Pb
exposure and motor functioning in 4 1/2-yr-old children: the Yugoslavia prospective study. J. Pediatr. 137:

555-561. Wasserman, G. A.; Liu, X.; Popovac, D.; Factor-Litvak, P.; K line, J.; Waternaux, C.; LoIacono, N.; Graziano, J. H.
(2000b) The Yugoslavia prospective Pb industry study: contributions of prenatal and postnatal Pb exposure to early intelligence. Neurotoxicol. Teratol. 22: 811-818.

# AX6-295 Wasserman, G. A.; Factor-Litvak, P.; Li u, X.; Todd, A. C.; Kline, J. K.; Sl avkovich, V.; Popovac, D.; Graziano,
J. H. (2003) The relationship between blood Pb, bon e Pb and child intelligence. Child Neuropsychol.

9: 22-34.

Weaver, V. M.; Lee, B.-K.; Ahn, K.-D.; Lee, G.-S.; Todd , A. C.; Stewart, W. F.; Wen, J.; Simon, D. J.; Parsons,
P. J.; Schwartz, B. S. (2003a) Associations of Pb biomarkers with renal function in Korean Pb workers. Occup. Environ. Med. 60: 551-562.

Weaver, V. M.; Schwartz, B. S.; Ahn, K.-D.; Stewart, W. F.; Kelsey, K. T.; Todd, A. C.; Wen, J.; Simon, D. J.;
Lustberg, M. E.; Parsons, P. J.; Silbergeld, E. K.; L ee, B.-K. (2003b) Associations of renal function with polymorphisms in the δ -aminolevulinic acid dehydratase, vitamin D receptor, and nitric oxide synthase
genes in Korean Pb workers. Environ. Health Perspect. 111: 1613-1619.

Weaver, V. M.; Lee, B.-K.; Todd, A. C.; Jaar, B. G.; Ahn, K.-D.; Wen, J.; Shi, W.; Parsons, P. J.; Schwartz, B. S. (2005a) Associations of patella Pb and other Pb biomarkers with renal function in Pb workers. J. Occup.

Environ. Med. 47: 235-243.

Weaver, V. M.; Jarr, B. G.; Schwartz, B. S.; Todd, A. C.; Ahn, K.-D.; Lee, S.-S.; Wen, J.; Parsons, P. J.; Lee, B.-K. (2005b) Associations among Pb dose biomarkers, uric acid, and renal function in Korean Pb workers.
Environ. Health Perspect. 113: 36-42.

Weaver, V. M.; Schwartz, B. S.; Jaar, B. G.; Ahn, K.-D.; Todd, A. C.; Lee, S.-S.; Kelsey, K. T.; Silbergeld, E. K.;
Lustberg, M. E.; Parsons, P. J.; Wen, J.; Lee-B.-K. (2005c) Associations of uric acid with polymorphisms

in the δ -aminolevulinic acid dehydratase, v itamin D receptor, and nitric oxid e synthase genes in Korean Pb workers. Environ. Health Perspect. 113: 1509-1515.

Wedeen, R. P.; Mallik, D. K.; Batuman, V. (1979) Detection and treatment of occupational Pb nephropathy. Arch.

Intern. Med. 139: 53-57. Wedeen, R. P.; Batuman, V.; Landy, E. (1983) The safety of the EDTA Pb-mobilization test. Environ. Res.

30: 58-62. Weinberg, C. R.; Baird, D. D.; Rowland, A. S. (1993) Pitfalls inherent in retrospective time-to-event studies: the example of time to pregnancy. Stat. Med. 12: 867-879.
Weinberg, C. R.; Baird, D. D.; Wilcox, A. J. (1994) Sources of bias in studies of time to pregnancy. Stat. Med.

13: 671-681. Weiss, S. T.; Munoz, A.; Stein, A.; Sparrow, D.; Speize r, F. E. (1986) The relationship of blood Pb to blood
pressure in a longitudinal study of working men. Am. J. Epidemiol. 123: 800-808.
Weisskopf, M. G.; Wright, R. O.; Schwartz, J.; Spiro, A. , III; Sparrow, D.; Aro, A.; Hu, H. (2004a) Cumulative Pb exposure and prospective change in cognition among elderly men. The VA Normative Aging Study. Am. J.
Epidemiol. 160: 1184-1193. Weisskopf, M. G.; Hu, H.; Mulkern, R. V.; White, R.; Aro, A.; Oliveira, S.; Wrigh t, R. O. (2004b) Cognitive
deficits and magnetic resonance spectroscopy in adult monozygotic twins with Pb poisoning. Environ.
Health Perspect. 112: 620-625. Wesseling, C.; Pukkala, E.; Neuvonen, K.; Kauppinen, T.; Bo ffetta, P.; Partanen, T. (2002) Cancer of the brain and
nervous system and ocupational exposures in Finnish women. J. Occup. Environ. Med. 44: 663-668.
Wibberley, D. G.; Khera, A. K.; Edwa rds, J. H.; Rushton, D. I. (1977) Pb levels in human placentae from normal

and malformed births. J. Med. Genet. 14: 339-345.
Wigg, N. R.; Vimpani, G. V.; McMichael, A. J.; Baghurst, P. A.; Robertson, E. F.; Roberts, R. J. (1988) Port Pirie
cohort study: childhood blood Pb and neuropsychological development at age two yrs. J. Epidemiol. Community Health 42: 213-219.
Wildt, K.; Berlin, M.; Isberg, P. E. (1987) Monitoring of zinc protoporphyrin levels in blood following occupational
Pb exposure. Am. J. Ind. Med. 12: 385-398. Wingren, G.; Axelson, O. (1985) Mortality pattern in a glass producing area in SE Sweden. Br. J. Ind. Med.

42: 411-414. Wingren, G.; Axelson, O. (1987) Mortality in the Swed ish glassworks industry. Scand. J. Work Environ.

Health 13: 412-416.
Wingren, G.; Axelson, O. (1993) Epidemiologic studies of occupational cancer as related to complex mixtures of
trace elements in the art glass in dustry. Scand. J. Work Environ. Health 19(supp l. 1): 95-100. Wingren, G. Englander, V. (1990) Mo rtality and cancer morbidity in a cohort of Swedish glassworkers. Int. Arch.
Occup. Environ. Health 62: 253-257. Winker, R.; Barth, A.; Ponocny-Seliger, E. ; Pilger, A.; Osterode, W.; Rüdiger, H. W. (2005) No cognitive deficits in
men formerly exposed to Pb. Wien. Klin. Wochenschr. 117: 755-760.

# AX6-296 Winker, R.; Ponocny-Seliger, E.; Rüdiger, H. W.; Barth, A. (2006) Pb exposure levels and duration of exposure
absence predict neurobehavioral performance. Int. Arch. Occup. Environ. Health 79: 123-127. Winneke, G.; Kraemer, U. (1984) Neuropsy chological effects of Pb in children: interactions with social background
variables. Neuropsychobiology 11: 195-202.

Winneke, G.; Brockhaus, A.; Ewers, U.; Kramer, U.; Neuf, M. (1990) Results from the European multicenter study on Pb neurotoxicity in children: implications for risk assessment. Neurotoxicol. Teratol. 12: 553-559.
Winterberg, B.; Korte, R.; Bertram, H. P. (1991) Response: bone Pb is elevated in renal failure [letter]. Nephron 58:

496-497.

Wittmers, L. E.; Aufderheide, A. C.; Wa llgren, J.; Rapp, G.; Alich, A. (1988) Pb in bone. IV. Distribution of Pb in

the human skeleton. Arch. Environ. Health 43: 381-391.

Wolf, A. W.; Ernhart, C. B.; White, C. S. (1985) Intrauterine Pb exposure and early development. In: Lekkas, T. D.,

ed. International conferen ce: heavy metals in the environment, v. 2; September; Athens, Greece.
Edinburgh, United Kingdom: CEP Consultants, Ltd.; pp. 153-155. Wong, O.; Harris, F. (2000) Cancer mortality study of em ployees at Pb battery plants and Pb smelters, 1947-1955.

Am. J. Ind. Med. 38: 255-270.
Work Group of the Advisory Committee on Childlhood Pb Poisoning Prevention. (2004) A review of evidence of

health effects of blood Pb levels <10 μ g/dl in children [draft final for ACCLPP review]. Centers for

Disease Control and Prevention, National Cent er for Environmental Health. Available:
http://www.cdc.gov/nceh/Pb/ACCLPP/meetingMinutes/lessThan10MtgMAR04.pdf [6 March, 2006]. World Health Organization. (1977) Pb. Geneva, Switzerland: World Health Organization. (Environmental health
criteria: v.3). Available: http://www.inchem.org/d ocuments/ehc/ehc/ehc003.htm [11 March, 2005].
World Health Organization. (1995) Inorganic Pb. Geneva, Switzerland: World Health Organization, International Programme on Chemical Safety. (Env ironmental health criteria 165).
Wright, R. O.; Hu, H.; Silverman, E. K.; Tsaih, S. W.; Sc hwartz, J.; Bellinger, D.; Pala zuelos, E.; Weiss, S. T.;
Hernandez-Avila, M. (2003) Apolipoprotein E genotype predicts 24-mo bayley scales infant development

score. Pediatr. Res. 54: 819-825.
Wu, T.-N.; Shen, C.-Y.; Ko, K.-N.; Guu, C.-F.; Gau, H.-J.; Lai, J.-S.; Chen, C.-J.; Chang, P.-Y. (1996) Occupational
Pb exposure and blood pressure. Int. J. Epidemiol. 25: 791-796. Wu, M. T.; Kelsey, K.; Schwartz, J.; Spar row, D.; Weiss, S.; Hu, H. (2003a) A δ

- aminolevulinic acid dehydratase
(ALAD) polymorphism may modify the relationship of low-level Pb exposure to uricemia and renal
function: the Normative Aging Study. Environ. Health Perspect. 111: 335-341.
Wu, T.; Buck, G. M.; Mendola, P. (2003b) Blood Pb levels and sexual maturation in U.S. girls: the Third National
Health and Nutrition Examination Survey, 1988-1994. Environ. Health Perspect. 111: 737-741. Ye, X. B.; Wu, C. E.; Fu, H.; Yang, S.-L.; Lu, Y.-W.; Ni , W.-M. (2003) Associations of blood Pb levels, kidney
function, and blood pressure with δ -aminolevulinic acid dehydratase and vitamin D receptor gene
polymorphisms. Toxicol. Mech. Methods 13: 139-146. Yokoyama, K.; Araki, S.; Murata, K.; Morita, Y.; Katsuno, N.; Tanigawa, T.; Mori, N.; Yokota, J.; Ito, A.; Sakata,
E. (1997) Subclinical vestibulo-cerebellar, anterior cerebellar lobe and spinocerebellar effects in Pb
workers in relation to concurrent and past exposure. Neurotoxicology 18: 371-380. Yokoyama, K.; Araki, S.; Aono , H.; Murata, K. (1998) Calcium disodium ethylenediaminetetr aacetate-chelated Pb
as a predictor for subclinical Pb neurotoxicity: follow- up study on gun-metal foundry workers. Int. Arch.
Occup. Environ. Health 71: 459-464. Young, S. S.; Hawkins, D. M. (1998) Using recursive partitioning to analyze a large SAR data set. SAR QSAR

Environ. Res. 8: 183-193.
Young, B. A.; Boyko, E. J.; Ross, H. J.; Fihn, S.; Brys on, C. L. (2004) Association of urine cadmium with hypertension, microalbuminuria and reduced renal function: results from the NHANES III study [abstract].
J. Am. Soc. Nephrol. 15: 146A.
Yu, C.-C.; Lin, J.-L.; Lin-Tan, D.-T. (2004) Environmental exposure to Pb and progression of chronic renal diseases: a four-yr prospective longitudinal study. J. Am. Soc. Nephrol. 15: 1016-1022.

Yuan, W.; Holland, S. K.; Cecil, K. M.; Dietrich, K. N.; Wessel, S. D.; Altaye, M.; Hornung, R. W.; Ris, M. D.;
Egelhoff, J. C.; Lanphear, B. P. (2006) The impact of early childhood Pb exposure on brain organization: a functional magnetic resonance imaging study of language function. Pediatrics 118: 971-977. Yücesoy, B.; Turhan, A.; Üre, M.; İ mir, T.; Karakaya, A. (1997a) Effects of occupational Pb and cadmium exposure on some immunoregulatory cytokine levels in man. Toxicology 123: 143-147. Yücesoy, B.; Turhan, A.; Üre, M.; İ mir, T.; Karakaya, A. (1997b) Simultaneous effects of Pb and cadmium on NK
cell activity and some phenotypic parameters. Immunopharmacol. Immunotoxicol. 19: 339-348.

# AX6-297 Yule, W.; Lansdown, R.; Millar, I. B.; Urbanowicz, M.-A. (1981) The relationship between blood Pb
concentrations, intelligence and attainment in a school population: a pilot study. Dev. Med. Child Neurol.

23: 567-576.

Yule, W.; Urbanowicz, M.-A.; Lansdown , R.; Millar, I. B. (1984) Teachers' ratings of children's behaviour in
relation to blood Pb levels. Br. J. Dev. Psychol. 2: 295-305. Zhao, Z. Y.; Li, R.; Sun, L.; Li, Z. Y.; Yang, R. L. (2 004) Effect of Pb exposure on the immune function of
lymphocytes and erythrocytes. in preschool children. J. Zhejiang Univ. Sci. 5(8): 1001-1004.
Zheng, W.; Lu, Y. M.; Lu, G. Y.; Zhao, Q.; Cheung, 0.; Bl aner, W. S. (2001) Transthyretin, thyroxine, and retinolbinding protein in human cerebrospinal fluid: effect of Pb exposure. Toxicol. Sci. 61(1): 107-114.
Zimmermann-Tansella, C.; Campara, P. ; Andrea, F. D.; Savontto, C.; Tans ella, m. (1983) Psychological and
physical complaints of subjects with low exposure to Pb. Hum. Toxicol. 2: 615-623. Zuckerman, B.; Amaro, H.; Cabral, H. (1989) Validity of self-reporting of marijuana and cocaine use among
pregnant adolescents. J. Pediatr. ( St. Louis) 115: 812-815.

# October 2006

EPA/600/R-05/144bF



# Air Quality Criteria for Lead

Volume II of II

# EPA/600/R-05/144bF

October 2006



# Air Quality Criteria for Lead

Volume II

National Center for Environmental Assessment-RTP Division
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, NC

# II-iii PREFACE

National Ambient Air Quality Standards (NAAQS ) are promulgated by the United States

Environmental Protection Agency (EPA) to meet requirements set forth in Sections 108 and 109

of the U.S. Clean Air Act. Those two Clean Air Act sections require the EPA Administrator

(1) to list widespread air pollutants that reasonabl y may be expected to endanger public health or

welfare; (2) to issue air qualit y criteria for them that assess the latest available scientific

information on nature and effects of ambient e xposure to them; (3) to set “primary” NAAQS to

protect human health with ade quate margin of safety and to set “secondary” NAAQS to protect

against welfare effects (e.g., effects on vegeta tion, ecosystems, visibility, climate, manmade

materials, etc); and (5) to peri odically review and revise, as appropriate, the criteria and NAAQS

for a given listed pollutant or class of pollutants.

Lead was first listed in the mid-1970’s as a “criteria air pollutant” requiring NAAQS

regulation. The scientific inform ation pertinent to Pb NAAQS de velopment available at the time

was assessed in the EPA document Air Quality Criteria for Lead ; published in 1977. Based on

the scientific assessments contained in that 1977 lead air quality criteria document (1977 Lead

AQCD), EPA established a 1.5 μg/m 3 

# (maximum quarterly calendar average) Pb NAAQS in

1978.

To meet Clean Air Act requirements noted above for periodic review of criteria and

NAAQS, new scientific information published si nce the 1977 Lead AQCD was later assessed in

a revised Lead AQCD and Addendum published in 1986 and in a Supplement to the 1986

AQCD/Addendum published by EPA in 1990. A 1990 L ead Staff Paper, prepared by EPA’s

Office of Air Quality Planning and Standards (OPQPS), drew upon key findings and conclusions

from the 1986 Lead AQCD/Addendum and 1990 Supplement (as well as other OAQPSsponsored lead exposure/risk analyses) in posing options for the EPA Administrator to consider

with regard to possible revision of the Pb NAAQS . However, EPA chose not to revise the Pb

NAAQS at that time. Rather , as part of implementing a broad 1991 U.S. EPA Strategy for

Reducing Lead Exposure, the Agency focused primarily on regulatory and remedial clean-up

efforts to reduce Pb exposure from a variety of non-air sources that posed more extensive public

health risks, as well as other actions to reduce air emissions.

# II-iv The purpose of this revised Lead AQCD is to critically assess the latest scientific

information that has become available sin ce the literature asse ssed in the 1986 Lead

AQCD/Addendum and 1990 Supplement, with the main focus being on pertinent new

information useful in evaluating health and enviro nmental effects of ambien t air lead exposures.

This includes discussion in this document of information rega rding: the nature, sources,

distribution, measurement, and c oncentrations of lead in the environment; multimedia lead

exposure (via air, food, water, et c.) and biokinetic modeling of c ontributions of such exposures

to concentrations of lead in brain, kidney, a nd other tissues (e.g., blood and bone concentrations,

as key indices of lead exposure).; characterization of l ead health effects and associated exposureresponse relationships; and delineation of environmen tal (ecological) effects of lead. This final

version of the revised Lead AQCD mainly assesses pertinent literature published or accepted for

publication through December 2005.

The First External Review Draft (dated December 2005) of the revised Lead AQCD

underwent public comment and was reviewed by the Clean Air Scientific Advisory Committee

(CASAC) at a public meeting held in Durham , NC on February 28-March 1, 2006. The public

comments and CASAC recommendations receiv ed were taken into account in making

appropriate revisions and incorporating them in to a Second External Review Draft (dated May,

2006) which was released for further public co mment and CASAC review at a public meeting

held June 28-29, 2006. In addition, still further revised drafts of the Integrative Synthesis

chapter and the Executive Summary were then issued and discussed during an August 15, 2006

CASAC teleconference call. Public commen ts and CASAC advice received on these latter

materials, as well as Second External Review Draf t materials, were taken into account in making

and incorporating further revisions into this fi nal version of this Lead AQCD, which is being

issued to meet an October 1, 2006 court-ordered d eadline. Evaluations c ontained in the present

document provide inputs to an associated Lead Staff Paper prepared by EPA’s Office of Air

Quality Planning and Standards (OAQPS), which poses options for consideration by the EPA

Administrator with regard to proposal and, ul timately, promulgation of decisions on potential

retention or revision, as appropriate, of the current Pb NAAQS.

Preparation of this document has been coordi nated by staff of EPA’s National Center for

Environmental Assessment in Research Triangl e Park (NCEA-RTP). NCEA-RTP scientific

staff, together with experts from academia, contri buted to writing of docum ent chapters. Earlier

# II-v drafts of document materials were reviewed by scientists from other EPA units and by non-EPA

experts in several public peer consultation workshops held by EPA in July/August 2005.

NCEA acknowledges the valuab le contributions provided by authors, contributors, and

reviewers and the diligence of its staff and contractors in the prep aration of this document. The

constructive comments provided by public comment ers and CASAC that served as valuable

inputs contributing to improved scientific and editorial quality of the document are also

acknowledged by NCEA.

DISCLAIMER

Mention of trade names or commercial produc ts in this document does not constitute

endorsement or recommendation for use.

.

# II-vi 

# Air Quality Criteria for Lead (Second External Review Draft)

VOLUME I

EXECUTIVE SUMMARY .........................................................................................................E-1

1. INTRODUCTION ........................................................................................................... 1-1

2. CHEMISTRY, SOURCES, AN D TRANSPORT OF LEAD.......................................... 2-1

3. ROUTES OF HUMAN EXPOSURE TO LEAD AND OBSERVED

ENVIRONMENTAL CONCENTRATIONS.................................................................. 3-1

4. TOXICOKINETICS, BIOLOGICAL MARKERS, AND MODELS OF LEAD

BURDEN IN HUMANS.................................................................................................. 4-1

5. TOXICOLOGICAL EFFECTS OF LEAD IN LABORATORY ANIMALS

AND IN VITRO TEST SYSTEMS................................................................................. 5-1

6. EPIDEMIOLOGIC STUDIES OF HUMAN HEALTH EFFECTS

ASSOCIATED WITH LEAD EXPOSURE.................................................................... 6-1

7. ENVIRONMENTAL EFFECTS OF LEAD ................................................................... 7-1

8. INTEGRATIVE SYNTHESIS OF LEAD EXPOSURE/HEALTH

EFFECTS INFORMATION............................................................................................ 8-1



# VOLUME II

CHAPTER 4 ANNEX (TOXICOKINETICS , BIOLOGICAL MARKERS, AND
MODELS OF LEAD BURDEN IN HUMANS)..................................................... AX4-1

CHAPTER 5 ANNEX (TOXICOLOGICAL EFFECTS OF LEAD IN
LABORATORY ANIMALS AND IN VITRO TEST SYSTEMS)................ AX5-1

CHAPTER 6 ANNEX (EPIDEMIOLOGIC STUDIES OF HUMAN HEALTH

EFFECTS ASSOCIATED WITH LEAD EXPOSURE)................................. AX6-1

CHAPTER 7 ANNEX (ENVIRONMENTA L EFFECTS OF LEAD).................................. AX7-1

# II-vii Table of Contents

Page

PREFACE........................................................................................................................ ..............iii

DISCLAIMER ................................................................................................................................ v

List of Tables ................................................................................................................. ................ xi
List of Figures................................................................................................................ ..............xiii

Authors, Contributors, and Reviewers.......................................................................................... x v U.S. Environmental Protection Agency Project Team for Development
of Air Quality Criteria for Lead.......................................................................................... .... xxi
U.S. Environmental Protection Agency Science Advisory Board (SAB)
Staff Office Clean Air Scientific Advisory Committee (CASAC).......................................xxiii
Abbreviations and Acronyms ..................................................................................................... xxv

AX7. CHAPTER 7 ANNEX (ENVIRONMEN TAL EFFECTS OF LEAD).................... AX7-1

AX7.1 TERRESTRIAL ECOSYSTEMS............................................................ AX7-1 AX7.1.1 Methodologies Used in Terrestrial Ecosystems

Research............................................................................... AX7-1
AX7.1.1.1 Lead Isotopes and Apportionment................. AX7-1
AX7.1.1.2 Speciation in Assessing Lead
Bioavailability in the Terrestrial

Environment................................................... AX7-3
AX7.1.1.3 Tools for Bulk Lead Quantification
and Speciation................................................ AX7-9
AX7.1.1.4 Biotic Ligand Model.................................... AX7-18

AX7.1.1.5 Soil Amendments......................................... AX7-19
AX7.1.2 Distribution of Atmosp herically Delivered Lead in
Terrestrial Ecosystems....................................................... AX7-22
AX7.1.2.1 Speciation of Atmo spherically-Delivered
Lead in Terrestrial Ecosystems.................... AX7-24
AX7.1.2.2 Tracing the Fate of AtmosphericallyDelivered Lead in Terrestrial
Ecosystems................................................... AX7-31 AX7.1.2.3 Inputs/Outputs ofAtmosphericallyDelivered Lead in Terrestrial
Ecosystems................................................... AX7-34

AX7.1.2.4 Resistance Mechanisms ............................... AX7-44
AX7.1.2.5 Physiological Effects of Lead ...................... AX7-46
AX7.1.2.6 Factors that Modify Organism Response..... AX7-48
AX7.1.2.7 Summary...................................................... AX7-55 AX7.1.3 Exposure-Response of Terrestrial Species......................... AX7-57
AX7.1.3.1 Summary of Conclusions from the

1986 Lead Criteria Document...................... AX7-59

AX7.1.3.2 Recent Studies on the Effects of Lead
on Primary Producers................................... AX7-61

# II-viii Table of Contents
(cont’d)

Page

AX7.1.3.3 Recent Studies on the Effects of Lead

on Consumers............................................... AX7-64

AX7.1.3.4 Recent Studies on the Effects of Lead
on Decomposers........................................... AX7-81
AX7.1.3.5 Summary...................................................... AX7-86

AX7.1.4 Effects of Lead on Natu ral Terrestrial Ecosystems ........... AX7-88
AX7.1.4.1 Effects of Terrestrial Ecosystem Stresses
on Lead Cycling........................................... AX7-89
AX7.1.4.2 Effects of Lead Exposure on Natural
Ecosystem Structure and Function............... AX7-95
AX7.1.4.3 Effects of Lead on Energy Flows and
Biogeochemical Cycling.............................. AX7-99
AX7.1.4.4 Summary.................................................... AX7-105
AX7.2 AQUATIC ECOSYSTEMS................................................................. AX7-106 AX7.2.1 Methodologies Used in Aquatic Ecosystem Research..... AX7-106
AX7.2.1.1 Analytical Methods.................................... AX7-107
AX7.2.1.2 Ambient Water Quality Criteria:
Development.............................................. AX7-108
AX7.2.1.3 Ambient Water Quality Criteria:
Bioavailability Issues................................. AX7-111
AX7.2.1.4 Sediment Quality Criteria: Development and Bioavaila bility Issues.... AX7-113

AX7.2.1.5 Metal Mixtures........................................... AX7-116
AX7.2.1.6 Background Lead....................................... AX7-117

AX7.2.2 Distribution of Lead in Aquatic Ecosystems ................... AX7-117
AX7.2.2.1 Speciation of Lead in Aquatic
Ecosystems................................................. AX7-118 AX7.2.2.2 Spatial Distribution of Lead in
Aquatic Ecosystems................................... AX7-122 AX7.2.2.3 Tracing the Fate and Transport of
Lead in Aquatic Ecosystems...................... AX7-142
AX7.2.2.4 Summary.................................................... AX7-145 AX7.2.3 Aquatic Species Re sponse/Mode of Action..................... AX7-146
AX7.2.3.1 Lead Uptake............................................... AX7-146

AX7.2.3.2 Resistance Mechanisms ............................. AX7-152
AX7.2.3.3 Physiological Effects of Lead .................... AX7-159
AX7.2.3.4 Factors That Modify Organism
Response to Lead ....................................... AX7-162

AX7.2.3.5 Factors Associated with Global
Climate Change.......................................... AX7-174
AX7.2.3.6 Summary.................................................... AX7-174

# II-ix Table of Contents
(cont’d)

Page

AX7.2.4 Exposure/Response of Aquatic Species........................... AX7-175
AX7.2.4.1 Summary of Conc lusions From the

Previous Criteria Document....................... AX7-175

AX7.2.4.2 Recent Studies on Effects of Lead on
Primary Producers...................................... AX7-177

AX7.2.4.3 Recent Studies on Effects of Lead

on Consumers............................................. AX7-183

AX7.2.4.4 Recent Studies on Effects of Lead
on Decomposers......................................... AX7-193
AX7.2.4.5 Summary.................................................... AX7-193

AX7.2.5 Effects of Lead on Na tural Aquatic Ecosystems ............. AX7-194
AX7.2.5.1 Case Study: Coeur d’Alene River

Watershed .................................................. AX7-196

AX7.2.5.2 Biotic Condition......................................... AX7-198
AX7.2.5.3 Summary.................................................... AX7-209

REFERENCES .................................................................................................... AX7-211

# II-x List of Tables

Page

AX7-1.1.1 Relative Standard Deviation (R SD) for Lead Isotope Ratios on
Selected Mass Spectrometers................................................................... AX7-2

AX7-1.1.2 National Institute of Standa rds and Technology Lead SRMs................ AX7-10

AX7-1.1.3 Characteristics for Direct Speciation Techniques.................................. AX7-17

AX7-1.2.1 Tissue Lead Levels in Birds Causing Effects ........................................ AX7-43

AX7-1.3.1 Plant Toxicity Data Used to Develop the Eco-SSL............................... AX7-62

AX7-1.3.2 Plant Toxicity Data Not Us ed to Develop the Eco-SSL........................ AX7-63

AX7-1.3.3 Avian Toxicity Data Used to Develop the Eco-SSL ............................. AX7-66

AX7-1.3.4 Mammalian Toxicity Data Us ed to Develop the Eco-SSL.................... AX7-72

AX7-1.3.5 Invertebrate Toxicity Data Used to Develop the Eco-SSL.................... AX7-82

AX7-1.3.6 Invertebrate Toxicity Data No t Used to Develop the Eco-SSL............. AX7-84

AX7-2.1.1 Common Analytical Methods for Measuring Lead in Water,

Sediment, and Tissue .......................................................................... AX7-107

AX7-2.1.2 Development of Curre nt Acute Freshwater Cr iteria for Lead ............. AX7-109

AX7-2.1.3 Recommended Sediment Quality Guidelines for Lead ....................... AX7-115

AX7-2.2.1 NAWQA Land Use Categorie s and Natural/Ambient

Classification........................................................................................ AX7-125

AX7-2.2.2 Summary Statistics of Ambient and Natural Levels of Dissolved

Lead in Surface Water ......................................................................... AX7-126

AX7-2.2.3 Summary Statistics of Ambien t and Natural Levels of Total
Lead in <63 μm Bulk Sediment........................................................... AX7-127

AX7-2.2.4 Summary Statistics of Ambient and Natural Levels of Lead in
Whole Organism and Liver Tissues..................................................... AX7-136

AX7-2.2.5 Comparison of NCBP and NA WQA Ambient Lead Levels in
Whole Organism Tissues ..................................................................... AX7-138

# II-xi List of Tables
(cont’d)

Page

AX7-2.3.1 Bioconcentration Factors for Aquatic Plants ....................................... AX7-151

AX7-2.3.2 Bioconcentration Factors fo r Aquatic Invertebrates............................ AX7-151

AX7-2.4.1 Effects of Lead to Freshwater and Marine Invertebrates..................... AX7-185

AX7-2.4.2 Effects of Pb to Freshw ater and Marine Fish....................................... AX7-190

AX7-2.4.3 Nonlethal Effects in Amphibians......................................................... AX7-192

AX7-2.5.1 Ecological Attributed Studies by Maret et al. (2003) in the

Coeur d’Alene Watershed.................................................................... AX7-197

AX7-2.5.2 Essential Ecological Attributes for Natural Aquatic Ecosystems
Affected by Lead.................................................................................. AX7-200

# II-xii List of Figures

Number Page

AX7-1.1.1 Relationship of bioaccessibil ity (low, medium, high) versus
speciation as shown with scanning electron micrographs of
various Pb-bearing materials........................................................................ AX7-5

AX7-1.1.2 Variation of bioavailabil ity with particle size.............................................. AX7-7

AX7-1.1.3 Illustration of particle lability and bioavailability at two different

sites with similar total Pb concentrations and Pb forms .............................. AX7-8

AX7-1.1.4 Scanning electron micrograph of a large native Pb particle showing
outer ring of highly bioavailable Pb-chloride and Pb-oxide........................ AX7-8

AX7-1.1.5 Bulk lead versus single species modality................................................... AX7-12

AX7-1.2.1 Long-term (1982-1989) annual trends in lead concentrations (μg/L)
in Lewes, Delaware precipitation .............................................................. AX7-35

AX7-1.3.1 Avian reproduction and growth toxicity data considered in
development of the Eco-SSL ..................................................................... AX7-69

AX7-1.3.2 Mammalian reproduction and growth toxicity data considered in
development of the Eco-SSL ..................................................................... AX7-81

AX7-2.2.1 Distribution of aqueous lead sp ecies as a function of pH based on
a concentration of 1 μg Pb/L.................................................................... AX7-119

AX7-2.2.2 Lead speciation versus chloride content .................................................. AX7-121

AX7-2.2.3 Spatial distribution of natural and ambient surface water/sediment

sites .......................................................................................................... AX7-128

AX7-2.2.4 Spatial distribution of natural and ambient liver tissue sample sites....... AX7-129

AX7-2.2.5 Spatial distribution of natural and ambient whole organism tissue
sample sites .............................................................................................. AX7-130

AX7-2.2.6 Frequency distribution of ambi ent and natural levels of surface
water dissolved lead (μg/L). .................................................................... AX7-131

AX7-2.2.7 Spatial distribution of dissolved l ead in surface water (N = 3445). ........ AX7-132

# II-xiii List of Figures
(cont’d)

Number Page

AX7-2.2.8 Frequency distribution of ambi ent and natural levels of bulk
sediment <63 μm total Pb (μg/g)............................................................. AX7-134

AX7-2.2.9 Spatial distribution of total lead in bulk sediment <63 um
(N = 1466)................................................................................................ AX7-135

AX7-2.2.10 Frequency distribution of ambien t and natural levels of lead in
liver tissue (μg/g dry weight)................................................................... AX7-137

AX7-2.2.11 Frequency distribution of ambien t and natural levels of lead in
whole organism tissue (μg/g dry weight). ............................................... AX7-137

AX7-2.2.12 Spatial distribution of lead in liver tissues (N = 559). ............................. AX7-139

AX7-2.2.13 Spatial distribution of lead in whole organism tissues (N = 332)............ AX7-140

AX7-2.2.14 Lead cycle in an aquatic ecosystem......................................................... AX7-143

# II-xiv Authors, Contributors, and Reviewers

CHAPTER 4 ANNEX (TOXICOKINETIC S, BIOLOGICAL MARKERS, AND
MODELS OF LEAD BURDEN IN HUMANS)

Chapter Managers/Editors

Dr. James Brown—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Principal Authors

Dr. Brian Gulson—Graduate School of the Environment, Macquarie University
Sydney, NSW 2109, Australia

Contributors and Reviewers

Dr. Lester D. Grant—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. John Vandenberg—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

CHAPTER 5 ANNEX (TOXICOLOGICAL EFFECTS OF LEAD IN HUMANS
AND LABORATORY ANIMALS)

Chapter Managers/Editors

Dr. Anuradha Mudipalli—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Srikanth Nadadur—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Lori White—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

# II-xv Authors, Contributors, and Reviewers
(cont’d)

Principal Authors

Dr. Anuradha Mudipalli—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Stephen Lasley—Dept. of Biomedical and Ther apeutic Sciences, Univ. of Illinois College of

Medicine, PO Box 1649, Peoria, IL 61656

Dr. Lori White—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Gary Diamond— Syracuse Research Cor poration, 8191 Cedar Street, Akron, NY 14001

Dr. N.D. Vaziri—Division of Nephrology and Hype rtension, University of California – Irvine
Medical Center, 101, The City Drive, Bldg 53, Room #125. Orange, CA 92868

Dr. John Pierce Wise, Sr.—Maine Center fo r Toxicology and Environmental Health,
Department of Applied Medical Sciences, 96 Falmouth Street, PO Box 9300, Portland, ME

04104-9300

Dr. Harvey C. Gonick—David Geffen School of Medicine, University of California at
Los Angeles, 201 Tavistock Ave, Los Angeles, CA 90049

Dr. Gene E. Watson—University of Rochester Medical Center, Box 705, Rochester, NY 14642

Dr. Rodney Dietert—Institute for Comparativ e and Environmental Toxicology, College of
Veterinary Medicine, Cornel l University, Ithaca, NY 14853

Contributors and Reviewers

Dr. Lester D. Grant—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Paul Reinhart—Nationa l Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Michael Davis—Nationa l Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. David A. Lawrence—Dept of Environmental and Clinical Immunology, Empire State Plaza
P.O. Box 509, Albany, NY 12201

# II-xvi Authors, Contributors, and Reviewers
(cont’d)

Contributors and Reviewers
(cont’d)

Dr. Michael J. McCabe, Jr.—Dept of Environm ental Medicine, University of Rochester,

575 Elmwood Avenue, Rochester, NY 14642

Dr. Theodore I. Lidsky—New York State Inst itute for Basic Research, 1050 Forest RD,

Staten Island, NY 10314

Dr. Mark H. Follansbee—Syracuse Research Corporation, 8191 Cedar St. Akron, NY 14001

Dr. William K. Boyes—National Health and En vironmental Effects Research Laboratory,
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Philip J. Bushnell—National Health and Environmental Effects Research Laboratory,
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Ms. Beth Hassett-Sipple—Office of Air Quality Planning and Standards, U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711

Dr. Zachary Pekar—Office of Air Quality Pla nning and Standards, U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711

Dr. John Vandenberg—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

CHAPTER 6 ANNEX (EPIDEMIOLOGICA L STUDIES OF AMBIENT LEAD
EXPOSURE EFFECTS)

Chapter Managers/Editors

Dr. Jee Young Kim—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Dennis Kotchmar—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. David Svendsgaard—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

# II-xvii Authors, Contributors, and Reviewers
(cont’d)

Principal Authors

Dr. David Bellinger—Children’s Hospital, Fa rley Basement, Box 127, 300 Longwood Avenue,

Boston, MA 02115

Dr. Margit Bleecker—Center for Occupational and Environmental Neurology, 2 Hamill Road,

Suite 225, Baltimore, MD 21210

Dr. Gary Diamond— Syracuse Resear ch Corporation, 8191 Cedar Street.

Akron, NY 14001

Dr. Kim Dietrich—University of Cincinnati College of Medicine, 3223 Eden Avenue,
Kettering Laboratory, Room G31, Cincinnati, OH 45267

Dr. Pam Factor-Litvak—Columbia University Mailman School of Public Health,

722 West 168th Street, Ro om 1614, New York, NY 10032

Dr. Vic Hasselblad—Duke University Medical Center, Durham, NC 27713

Dr. Stephen J. Rothenberg—CINVESTAV-IPN, Mé rida, Yucatán, México & National Institute

of Public Health, Cuernavaca, Morelos, Mexico

Dr. Neal Simonsen—Louisiana State University Hea lth Sciences Center, School of Public Health & Stanley S Scott Cancer Center, 1600 Cana l Street, Suite 800, New Orleans, LA 70112

Dr. Kyle Steenland—Rollins School of Public Health, Emory University, 1518 Clifton Road,

Room 268, Atlanta, GA 30322

Dr. Virginia Weaver—Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe

Street, Room 7041, Baltimore, MD 21205

Contributors and Reviewers

Dr. J. Michael Davis—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Lester D. Grant—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Kazuhiko Ito—Nelson Institute of Environmental Medicine, Ne w York University School of

Medicine, Tuxedo, NY 10987

# II-xviii Authors, Contributors, and Reviewers
(cont’d)

Contributors and Reviewers
(cont’d)

Dr. Kathryn Mahaffey—Office of Prevention, Pesticides and Toxic Substances,
U.S. Environmental Protection Agency, Washington, DC 20460

Dr. Karen Martin—Office of Air Quality Pl anning and Standards, U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711

Dr. Zachary Pekar—Office of Air Quality Pla nning and Standards, U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711

Ms. Beth Hassett-Sipple—Office of Air Quality Planning and Standards, U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711

Dr. John Vandenberg—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

CHAPTER 7 ANNEX (ENVIRONME NTAL EFFECTS OF LEAD)

Chapter Manager/Editor

Dr. Timothy Lewis—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Principle Authors

Dr. Ruth Hull—Cantox Environmental Inc., 190 0 Minnesota Court, Suite 130, Mississauga,

Ontario, L5N 3C9 Canada

Dr. James Kaste—Department of Earth Scienc es, Dartmouth College, 352 Main Street,

Hanover, NH 03755

Dr. John Drexler—Department of Geologica l Sciences, University of Colorado,
1216 Gillespie Drive, Boulder, CO 80305

Dr. Chris Johnson—Department of Civil and Envir onmental Engineering, Syracuse University,
365 Link Hall, Syracuse, NY 13244

Dr. William Stubblefield—Parametrix, Inc. 33972 Texas St. SW, Albany, OR 97321

# II-xix Authors, Contributors, and Reviewers
(cont’d)

Principle Authors
(cont’d)

Dr. Dwayne Moore—Cantox Environmental, Inc., 1550A Laperriere Avenue, Suite 103,

Ottawa, Ontario, K1Z 7T2 Canada

Dr. David Mayfield—Parametrix, Inc., 411 108th Ave NE, Suite 1800, Bellevue, WA 98004

Dr. Barbara Southworth—Menzie-Cura & Associ ates, Inc., 8 Winchester Place, Suite 202,

Winchester, MA 01890

Dr. Katherine Von Stackleberg—Menzie-Cura & Associates, Inc., 8 Winchester Place,

Suite 202, Winchester, MA 01890

Contributors and Reviewers

Dr. Jerome Nriagu—Department of Environmenta l Health Sciences, 109 South Observatory,
University of Michigan, Ann Arbor, MI 48109

Dr. Judith Weis—Department of Biol ogy, Rutgers University, Newark, NJ 07102

Dr. Sharon Harper—National Exposure Research Laboratory (D205-05), U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711

Dr. Karen Bradham—National Research Exposur e Laboratory (D205-05), U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711

Dr. Ginger Tennant—Office of Air Quality Plan ning and Standards, U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711

Ms. Gail Lacey—Office of Air Quality Planning a nd Standards, U.S. Environmental Protection
Agency, Research Triangle Park, NC 27711

Dr. John Vandenberg—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

# II-xx U.S. Environmental Protection Agency Project Team

for Development of Air Quality Criteria for Lead

Executive Direction

Dr. Lester D. Grant (Director)—National Cent er for Environmental Assessment-RTP Division,
(B243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Scientific Staff

Dr. Lori White (Lead Team Leader)—Nati onal Center for Environmental Assessment
(B243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. James S. Brown—National Center fo r Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Robert Elias—Nationa l Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Re search Triangle Park, NC 27711 (Retired)

Dr. Brooke Hemming—National Center for Environmental Assessment (B243-01), U.S.
Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Jee Young Kim—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Dennis Kotchmar—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Timothy Lewis—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Anuradha Muldipalli—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Srikanth Nadadur—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Paul Reinhart—Nationa l Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. Mary Ross— National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Dr. David Svendsgaard—National Center for Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

# II-xxi U.S. Environmental Protection Agency Project Team

for Development of Air Quality Criteria for Lead
(cont’d)

Technical Support Staff

Mr. Douglas B. Fennell—Technical Information Sp ecialist, National Center for Environmental
Assessment (B243-01), U.S. Environmental Prot ection Agency, Research Triangle Park, NC
27711 (Retired)

Ms. Emily R. Lee—Management Analyst, Natio nal Center for Environmental Assessment
(B243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Ms. Diane H. Ray—Program Specialist, Natio nal Center for Environmental Assessment
(B243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Ms. Donna Wicker—Administrative Officer, National Center for Environmental Assessment
(B243-01), U.S. Environmental Protection Agenc y, Research Triangle Park, NC 27711 (Retired)

Mr. Richard Wilson—Clerk, National Center fo r Environmental Assessment (B243-01),
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

Document Production Staff

Ms. Carolyn T. Perry—Task Order Manager, Com puter Sciences Corpor ation, 2803 Slater Road,

Suite 220, Morrisville, NC 27560

Mr. John A. Bennett—Technical Information Sp ecialist, Library Asso ciates of Maryland,

11820 Parklawn Drive, Suite 400, Rockville, MD 20852

Mr. William Ellis—Records Management Technician, InfoPro, Inc., 8200 Greensboro Drive,

Suite 1450, McLean, VA 22102

Ms. Sandra L. Hughey—Technical Information Sp ecialist, Library Associates of Maryland,

11820 Parklawn Drive, Suite 400, Rockville, MD 20852

Dr. Barbara Liljequist—Technical Editor, Comp uter Sciences Corporation, 2803 Slater Road,

Suite 220, Morrisville, NC 27560

Ms. Michelle Partridge-Doerr—Publications/Gra phics Specialist, TEK Systems, 1201 Edwards
Mill Road, Suite 201, Raleigh, NC 27607

Mr. Carlton Witherspoon—Graphic Artist, Comput er Sciences Corporation, 2803 Slater Road,

Suite 220, Morrisville, NC 27560

# II-xxii U.S. Environmental Protection Agency
Science Advisory Board (SAB) Staff Office

Clean Air Scientific Advi sory Committee (CASAC)

Chair

Dr. Rogene Henderson*—Scientist Emeritus, Lovelace Respiratory Research Institute,
Albuquerque, NM

Members

Dr. Joshua Cohen—Faculty, Center for the Evaluati on of Value and Risk, Institute for Clinical
Research and Health Policy Studies, Tuft s New England Medical Center, Boston, MA

Dr. Deborah Cory-Slechta—Director, University of Medicine and Dentistry of New Jersey and
Rutgers State University, Piscataway, NJ

Dr. Ellis Cowling*—University Distinguished Professor-at-Large, North Carolina State
University, Colleges of Natural Resources and Agriculture and Life Sciences, North Carolina
State University, Raleigh, NC

Dr. James D. Crapo [M.D.]*—Professor, Departme nt of Medicine, National Jewish Medical and

Research Center, Denver, CO

Dr. Bruce Fowler—Assistant Director for Scien ce, Division of Toxicology and Environmental Medicine, Office of the Director, Agency for Toxic Substances and Disease Registry, U.S.

Centers for Disease Control and Pr evention (ATSDR/CDC), Chamblee, GA

Dr. Andrew Friedland—Professo r and Chair, Environmental Studies Program, Dartmouth
College, Hanover, NH

Dr. Robert Goyer [M.D.]—Emeritu s Professor of Pathology, Faculty of Medicine, University of
Western Ontario (Canada), Chapel Hill, NC

Mr. Sean Hays—President, Summ it Toxicology, Allenspark, CO

Dr. Bruce Lanphear [M.D.]—Sloan Professor of Children’s Environmental Health, and the

Director of the Cincinnati Ch ildren’s Environmental Health Ce nter at Cincinnati Children’s
Hospital Medical Center and the Univer sity of Cincinnati, Cincinnati, OH

Dr. Samuel Luoma—Senior Research Hydr ologist, U.S. Geological Survey (USGS),

Menlo Park, CA

# II-xxiii U.S. Environmental Protection Agency
Science Advisory Board (SAB) Staff Office

Clean Air Scientific Advi sory Committee (CASAC)
(cont’d)

Members
(cont’d)

Dr. Frederick J. Miller*—Consultant, Cary, NC

Dr. Paul Mushak—Principal, PB A ssociates, and Visiting Professor, Albert Einstein College of
Medicine (New York, NY), Durham, NC

Dr. Michael Newman—Professor of Marine Science, School of Marine Sciences, Virginia
Institute of Marine Science, College of William & Mary, Gloucester Point, VA

Mr. Richard L. Poirot*—Environmental Analyst, Air Pollution Control Di vision, Department of
Environmental Conservation, Vermont Agency of Natural Resources, Waterbury, VT

Dr. Michael Rabinowitz—Geochemist, Marine Biological Laboratory, Woods Hole, MA

Dr. Joel Schwartz—Professor, Environmental H ealth, Harvard University School of Public

Health, Boston, MA

Dr. Frank Speizer [M.D.]*—Edward Kass Prof essor of Medicine, Channing Laboratory,

Harvard Medical School, Boston, MA

Dr. Ian von Lindern—Senior Scientist, TerraG raphics Environmenta l Engineering, Inc.,

Moscow, ID

Dr. Barbara Zielinska*—Research Professor, Divi sion of Atmospheric Science, Desert Research

Institute, Reno, NV

SCIENCE ADVISORY BOARD STAFF

Mr. Fred Butterfield—CASAC Designated Fede ral Officer, 1200 Pennsyl vania Avenue, N.W.,
Washington, DC, 20460, Phone: 202-343-9994, Fax: 202-233-0643 (butterfield.fred@epa.gov ) (Physical/Courier/FedEx Address: Fred A. Butterf ield, III, EPA Science Advisory Board Staff
Office (Mail Code 1400F), Woodies Building, 1025 F Street, N.W., Room 3604, Washington,
DC 20004, Telephone: 202-343-9994)

*Members of the statutory Clean Air Scientific Advisory Committee (CASAC) appointed by the

U.S. EPA Administrator

# II-xxiv Abbreviations and Acronyms

α FGF α -fibroblast growth factor

AA arachidonic acid

AAL active avoidance learning

AAS atomic absorption spectroscopy

ABA β -aminoisobutyric acid

ACBP Achenbach Child Behavior Profile

ACE angiotensin converting enzyme

ACh acetylcholine

AChE acetylcholinesterase

ACR acute-chronic ratio

AD adult

ADC analog digital converter

ADP adenosine diphosphate

AE anion exchange

AEA N -arachidonylethanolamine

AFC antibody forming cells

2-AG 2-arachidonylglycerol

A horizon uppermost layer of soil (litter and humus)

AHR aryl hydrocarbon receptor

AI angiotensin I

ALA ∗ -aminolevulinic acid

ALAD ∗ -aminolevulinic acid dehydratase

ALAS aminolevulinic acid synthetase

ALAU urinary δ -aminolevulinic acid

ALD aldosterone

ALS amyotrophic lateral sclerosis

ALT alanine aminotransferase

ALWT albumin weight

AMEM Alpha Minimal Essential Medium

AMP adenosine monophosphate

ANCOVA analysis of covariance

ANF atrial natriuretic factor

Ang II angiotensin II

# II-xxv ANOVA analysis of variance

ANP atrial natriuretic peptide

AP alkaline phosphatase

AP-1 activated protein-1

ApoE apolipoprotein E

AQCD Air Quality Criteria Document

Arg arginine

AS52 cells derived from the CHO cell line

ASGP-R aceyl glycoprotein receptor

AST aspartate aminotransferase

ASV anode stripping voltammetry

3-AT 3-aminotriazole; 3-amino triazide

ATP adenosine triphosphate

ATP1A2 sodium-potassium adenosine triphosphase α 2

ATPase adenosine triphosphatase

ATSDR Agency for Toxic Substances and Disease Research

AVCD atrioventricular conduction deficit

AVS acid volatile sulfide

AWQC ambient water quality criteria

∃ beta-coefficient; slope of an equation

∃ FGF ∃ -fibroblast growth factor

17 ∃ –HS 17 ∃ -hydroxysteriod

3 ∃ -HSD 3 ∃ -hydroxysteriod dehydrogenase

17 ∃ -HSDH 17 ∃ -hydroxysteriod dehydrogenase

6 ∃ -OH-cortisol 6- ∃ -hydroxycortisol

B both

BAEP brainstem auditory-evoked potentials

BAER brainstem audito ry-evoked responses

BAF bioaccumulation factor

B cell B lymphocyte

BCFs bioconcentration factors

BCS bovine calf serum

BDNF brain derived neurotrophic factor

BDWT body weight changes

BEI biological exposure index

# II-xxvi BFU-E blood erythroid progenitor

BLL blood lead level

BLM biotic ligand model

BM basement membrane

BMI body mass index

BDNF brain-derived ne urotrophic factor

BOTMP Bruinicks-Oseretsky Test of Motor Proficiency

BP blood pressure

BPb blood lead concentration

BSA bovine serum albumin

BSI Brief Symptom Inventory

BTQ Boston Teacher Questionnaire

BUN blood urea nitrogen

bw, b. wt., BW body weight

C3H10T/12 mouse embryo cell line

C3, C4 complement proteins

CA chromosome aberration

CA3 cornu ammonis 3 region of hippocampus

45 

# Ca calcium-45 radionuclide

Ca-ATP calcium-dependent adenosine triphosphate

Ca-ATPase calcium-dependent adenosine triphosphatase

CaCO 3 

# calcium carbonate

CaEDTA calcium disodium ethylenediaminetetraacetic acid

CAL calcitonin

CaM calmodulin

Ca-Mg-ATPase calcium-magnesium-dependent adenosine triphosphatase

cAMP cyclic adenosinemonophosphate

CaNa 2 

# EDTA calcium disodium ethyl enediaminetetraacetic acid

CANTAB Cambridge Neuropsychologi cal Testing Automated Battery

CAT catalase; Cognitive Abilities Test

CBCL Achenbach Child Behavior Checklist

CBCL-T Total Behavior Problem Score

CBL cumulative blood lead

CBLI cumulative blood lead index

CCB cytochalasin B

# II-xxvii CCD charge-coupled device

CCE Coordination Center for Effects

CCL carbon tetrachloride

CCS cosmic calf serum

C-CV RSA 

# coefficient of component variance of respiratory sinus arrhythmia

Cd cadmium

109 

# Cd cadmium-109 radionuclide

CdU urinary cadmium

CEC cation exchange capacity

CESD, CES-D Center for Epidemio logic Studies Depression (scale)

GFAP glial fibrillary acidic protein

CFU-E colony forming unit blood-er ythroid progenitor (cell count)

CFU-GEMM colony forming unit blood- pluripotent progen itor (cell count)

CFU-GM blood granulocyte/macro phage progenitor (cell count)

cGMP cyclic guanosine-3',5'-monophosphate

ChAT choline acetyltransferase

CHD coronary heart disease

CHO Chinese hamster ovary cell line

CI confidence interval

CLE-SV competitive ligand-exchange/stripping voltammetry

CLRTAP Convention on Long-Range Transboundary of Air Pollution

CLS Cincinnati Lead Study

CMC criterion maximum concentration

CMI cell-mediated immunity

CNS central nervous system

COH cation-osmotic hemolysis

ConA concanavalin A

COR cortisol

CoTx cotreatment

COX-2 cyclooxygenase-2

CP coproporphryn

CPT current perception threshold

cr creatinine

CRAC calcium release activated calcium reflux

CREB cyclic AMP-response element binding protein

# II-xxviii CRF chronic renal failure

CRI chronic renal insufficiency

CSF cerebrospinal fluid

CuZn-SOD copper and zinc-dependent superoxide dismutase

CV conduction velocity

CVLT California Verbal Learning Test

CV R-R 

# coefficient of variation of the R-R interval

CYP cytochrome (e.g., CYP1A, CYP-2A6, CYP3A4, CYP450)

CYP3a11 cytochrome P450 3a11

D D-statistic

DA dopamine; dopaminergic

dbcAMP dibutyryl cyclic ad enosine-3',5'-monophosphate

DCV distribution of conduction velocities

DEAE diethylaminoet hyl (chromatography)

DET diffusive equilibrium thin films

DEYO death of young

DFS decayed or filled surfaces, permanent teeth

dfs covariate-adjusted number of caries

DG dentate gyrus

DGT diffusive gradient thin films

DL DL-statistic

DMEM Dulbecco’s Minimal Essential Medium

DMEM/F12 Dulbecco’s Minimal Essential Medium/Ham’s F12

DMFS decayed, missing, or filled surfaces, permanent teeth

DMPS 2,3-dimercaptopropane 1-sulfonate

DMSA 2,3-dimercaptosuccinic acid

DMT Donnan membrane technique

DMTU dimethylthiourea

DNA deoxyribonucleic acid

DO distraction osteogenesis

DOC dissolved organic carbon

DOM dissolved organic carbon

DOPAc 3,4-dihydroxyphenylacetic acid

DPASV differential pulse anod ic stripping voltammetry

dp/dt rate of left ventri cular isovolumetric pressure

# II-xxix DPPD N

- N -diphenyl- p -phynylene-diamine

DR drinking water

DSA delayed spatial alternation

DTC diethyl dithiocarbomate complex

DTH delayed type hypersensitivity

DTPA diethylenetriaminepentaacetic acid

DTT dithiothreitol

dw dry weight

E embryonic day

E 2 

# estradiol

EBE early biological effect

EBV Epstein-Barr virus

EC European Community

EC 50 

# effect concentration fo r 50% of test population

eCB endocannabinoid

ECG electrocardiogram

Eco-SSL ecological soil screening level

EDS energy dispersive spectrometers

EDTA ethylenediaminetetraacetic acid

EEDQ N -ethoxycarbonyl-2-eth oxy-1,2-dihydroquinone

EEG electroencephalogram

EG egg

EGF epidermal growth factor

EGG effects on eggs

EGPN egg production

EKG electrocardiogram

electro electrophysiological stimulation

EM/CM experimental medium-to-control medium (ratio)

EMEM Eagle’s Minimal Essential Medium

eNOS endothelial nitr ic oxide synthase

EP erythrocyte protoporphyrin

EPA U.S. Environmental Protection Agency

Epi epinephrine

EPMA electron probe microanalysis

EPO erythropoietin

# II-xxx EPSC excitatory postsynaptic currents

EPT macroinvertebrates from the Ephemeroptera (mayflies),
Plecoptera (stoneflies), and Trichoptera (caddisflies) group

ERG electroretinogram; electroretinographic

ERL effects range – low

ERM effects range – median

EROD ethoxyresorufin- O -deethylase

ESCA electron spectroscopy for chemical analysis

ESRD end-stage renal disease

EST estradiol

ESTH eggshell thinning

ET endothelein; essential tremor

ETOH ethyl alcohol

EXAFS extended X-ray absorption fine structure

EXANES extended X-ray absorption near edge spectroscopy

F F-statistic

F344 Fischer 344 (rat)

FAV final acute value

FBS fetal bovine serum

FCS fetal calf serum

FCV final chronic value

FD food

FEF forced expiratory flow

FEP free erythrocyte protoporphyrin

FERT fertility

FEV 1 

# forced expiratory volume in one second

FGF fibroblast growth factor (e.g., β FGF, α FGF)

FI fixed interval (operant conditioning)

FIAM free ion activity model

FMLP N -formyl-L-methionyl-L-l eucyl-L-phenylalanine

fMRI functional magnetic resonance imaging

FR fixed-ratio operant conditioning

FSH follicle stimulating hormone

FT3 free triiodothyronine

FT4 free thyroxine

# II-xxxi FTES free testosterone

FTII Fagan Test of Infant Intelligence

FTPLM flow-through permeation liquid membranes

FURA-2 1-[6-amino-2-(5-carboxy-2- oxazolyl)-5-benzofuranyloxy]-2-(2-
amino-5-methylphenoxy) ethane- N

, N

, N'

, N' -tetraacetic acid

FVC forced vital capacity

( -GT ( -glutamyl transferase

G gestational day

GABA gamma aminobutyric acid

GAG glycosaminoglycan

G12 CHV79 cells derived from the V79 cell line

GCI General Cognitive Index

GD gestational day

GDP guanosine diphosphate

GEE generalized estimating equations

GFAAS graphite furnace atomic absorption spectroscopy

GFR glomerular filtration rate

GGT ( -glutamyl transferase

GH growth hormone

GI gastrointestinal

GIME-VIP gel integrated microelect rodes combined with voltammetric
in situ profiling

GIS geographic information system

GLU glutamate

GMAV genus mean acute value

GMCV genus mean chronic value

GMP guanosine monophosphate

GMPH general morphology

GnRH gonadotropin releasing hormone

GOT aspartate aminotransferase

GP gross productivity

G6PD, G6PDH glucose-6- phosphate dehydrogenase

GPEI glutathione S -transferase P enhancer element

gp91 phox 

# NAD(P)H oxidase

GPT glutamic-pyruvic transaminase

GPx glutathione peroxidase

# II-xxxii GRO growth

GRP78 glucose-regulated protein 78

GSD geometric standard deviation

GSH reduced glutathione

GSIM gill surface interaction model

GSSG glutathione disulfide

GST glutathione- S -transferase

GSTP placental glutathione transferase

GTP guanosine triphosphate

GV gavage

H + 

# acidity

3 

# H hydrogen-3 radionuclide (tritium)

HA humic acid; hydroxyapatite

Hb hemoglobin

HBEF Hubbard Brook Experimenatl Forest

HBSS Hank’s Balanced Salt Solution

HCG; hCG human chorionic gonadotropin

Hct hematocrit

HDL high-density lipopr otein (cholesterol)

HEP habitat evaluation procedure

HET Binghamton heterogeneous stock

HFPLM hollow fiber permeation liquid membranes

Hgb hemoglobin

HGF hepatocyte growth factor

HH hydroxylamine hydrochloride

H-H high-high

HHANES Hispanic Health and Nutrition Examination Survey

H-L high-low

HLA human leukocyte antigen

H-MEM minimum essential medium/nutrient mixture–F12-Ham

HMP hexose monophosphate shunt pathway

HNO 3 

# nitric acid

H 2 

# O 2 

# hydrogen peroxide

HOME Home Observation for Measurement of Environment

HOS TE human osteosarcoma cells

# II-xxxiii HPLC high-pressure liquid chromatography

H 3 

# PO 4 

# phosphoric acid

HPRT hypoxanthine phosphoribosyltransferase (gene)

HR heart rate

HSI habitat suitability indices

H 2 

# SO 4 

# sulfuric acid

HSPG heparan sulfate proteoglycan

Ht hematocrit

HTC hepatoma cells

hTERT catalytic subunit of human telomerase

HTN hypertension

IBL integrated blood lead index

IBL Η WRAT-R integrated blood lead index Η Wide Range Achievement
Test-Revised (interaction)

ICD International Classification of Diseases

ICP inductively coupled plasma

ICP-AES inductively coupled plas ma atomic emission spectroscopy

ICP-MS, ICPMS inductively coupl ed plasma mass spectrometry

ID-MS isotope dilution mass spectrometry

IFN interferon (e.g., IFN- ( )

Ig immunoglobulin (e.g., IgA, IgE, IgG, IgM)

IGF-1 insulin-like growth factor 1

IL interleukin (e.g., IL-1, IL-1 ∃ , IL-4, IL-6, IL-12)

ILL incipient lethal level

immuno immunohistochemical staining

IMP inosine monophosphate

iNOS inducible nitric oxide synthase

i.p., IP intraperitoneal

IPSC inhibitory postsynaptic currents

IQ intelligence quotient

IRT interresponse time

ISEL in situ end labeling

ISI interstimulus interval

i.v., IV intravenous

IVCD intraventricular conduction deficit

# II-xxxiv JV juvenile

KABC Kaufman Assessment Battery for Children

KTEA Kaufman Test of Educational Achievement

KXRF, K-XRF K-shell X-ray fluorescence

LA lipoic acid

LB laying bird

LC lactation

LC 50 

# lethal concentration at which 50% of exposed animals die

LC 74 

# lethal concentration at which 74% of exposed animals die

LD 50 

# lethal dose at which 50% of exposed animals die

LDH lactate dehydrogenase

LDL low-density lipoprotein (cholesterol)

L-dopa 3,4-dihydroxyphenylalanine (precursor of dopamine)

LE Long Evans (rat)

LET linear energy transfer (radiation)

LH luteinizing hormone

LHRH luteinizing hormone releasing hormone

LN lead nitrate

L-NAME L- N G 

# -nitroarginine methyl ester

LOAEL lowest-observed adverse effect level

LOEC lowest-observed-effect concentration

LOWESS locally weighted scatter plot smoother

LPO lipoperoxide

LPP lipid peroxidation potential

LPS lipopolysaccharide

LT leukotriene

LT 50 

# time to kill 50%

LTER Long-Term Ecological Research (sites)

LTP long term potentiation

LVH left ventricular hypertrophy

μPIXE microfocused particle induced X-ray emission

μSXRF microfocused synchrotron-based X-ray fluorescence

MA mature

MA-10 mouse Leydig tumor cell line

MANCOVA multivariate analysis of covariance

# II-xxxv MAO monoamine oxidase

MATC maximum acceptable threshold concentration

MDA malondialdehyde

MDA-TBA malondialdehyde-thiobarbituric acid

MDCK kidney epithelial cell line

MDI Mental Development Index (score)

MDRD Modification of Diet in Renal Disease (study)

MEM Minimal Essential Medium

MG microglobulin

Mg-ATPase magnesium-dependent adenosine triphosphatase

MiADMSA monoisamyl dimercaptosuccinic acid

Mi-DMSA mi monoisoamyl dimercaptosuccinic acid

MK-801 NMDA receptor antagonist

MLR mixed lymphocyte response

MMSE Mini-Mental State Examination

MMTV murine mammary tumor virus

MN micronuclei formation

MND motor neuron disease

MNNG N -methyl- N' -nitro- N -nitrosoguanidine

MPH morphology

MRI magnetic resonance imaging

mRNA messenger ribonucleic acid

MROD methoxyresorufin- O -demethylase

MRS magnetic resonance spectroscopy

MS mass spectrometry

MSCA McCarthy Scales of Children’s Abiltities

mSQGQs mean sediment quality guideline quotients

MT metallothionein

MVV maximum voluntary ventilation

MW molecular weight (e.g., high-MW, low-MW)

N, n number of observations

N/A not available

NAAQS National Ambient Air Quality Standards

NAC N -acetyl cysteine

NAD nicotinamide adenine dinucleotide

# II-xxxvi NADH reduced nicotinamide adenine dinucleotide

NADP nicotinamide adenine dinucleotide phosphate

NAD(P)H, NADPH reduced nicotinamide adenine dinucleotide phosphate

NADS nicotinamide adenine dinucleotide synthase

NAF nafenopin

NAG N -acetyl- ∃ -D-glucosaminidase

Na-K-ATPase sodium-potassium-dep endent adenosine triphosphatase

NAWQA National Water-Quality Assessment

NBT nitro blue tetrazolium

NCBP National Contaminant Biomonitoring Program

NCD nuclear chromatin decondensation (rate)

NCS newborn calf serum

NCTB Neurobehavioral Core Test Battery

NCV nerve conduction velocity

ND non-detectable; not detected

NDI nuclear divison index

NE norepinephrine

NES Neurobehavioral Evaluation System

NF- κ B nuclear transcription factor- κ B

NGF nerve growth factor

NHANES National Health and Nutrition Examination Survey

NIOSH National Institute for Occupational Safety and Health

NIST National Institute for Standards and Technology

NK natural killer

NMDA N -methyl-D-aspartate

NMDAR N -methyl-D-aspartate receptor

NMR nuclear magnetic resonance

NO nitric oxide

NO 2 

# nitrogen dioxide

NO 3 

# nitrate

NOAEC no-observed-adverse- effect concentration

NOAEL no-observed-adverse-effect level

NOEC no-observed-effect concentration

NOEL no-observed-effect level

NOM natural organic matter

# II-xxxvii NORs nucleolar organizing regions

NOS nitric oxide synthase ; not otherwise specified

NO

x 

# nitrogen oxides

NP net productivity

NPSH nonprotein sulfhydryl

NR not reported

NRC National Research Council

NRK normal rat kidney

NS nonsignificant

NSAID non-steroidal anti-inflammatory agent

NT neurotrophin

NTA nitrilotriacetic acid

O 2 

# oxygen

ODVP offspring development

OH hydroxyl

7-OH-coumarin 7-hydroxy-coumarin

1,25-OH-D, 1,25-OH D 3 

# 1,25-dihydroxyvitamin D

24,25-OH-D 3 

# 24,25-dihydroxyvitamin D

25-OH-D 3 

# 25-hydroxyvitamin D

8-OHdG 8-hydroxy-2'-deoxyguanosine

O horizon forest floor

OR odds ratio; other oral

OSWER Office of Solid Waste and Emergency Response

P, p probability value

P300 event-related potential

P450 1A1 cytochrome P450 1A1

P450 1A2 cytochrome P450 1A2

P450 CYP3a11 cytochrome P450 3a11

PAD peripheral arterial disease

PAH polycyclic aromatic hydrocarbon

PAI-1 plasminogen activator inhibitor-1

PAR population attributable risk

Pb lead

203 

# Pb lead-203 radionuclide

204 

# Pb, 206 

# Pb, 207 

# Pb, 208 

# Pb stable isotopes of lead-204, -206, -207, -208, respectively

# II-xxxviii 210 

# Pb lead-210 radionuclide

Pb(Ac) 2 

# lead acetate

PbB blood lead concentration

PbCl 2 

# lead chloride

Pb(ClO 4 

# ) 2 

# lead chlorate

PBG-S porphobilinogen synthase

PBMC peripheral bl ood mononuclear cells

Pb(NO 3 

# ) 2 

# lead nitrate

PbO lead oxides (or litharge)

PBP progressive bulbar paresis

PbS galena

PbU urinary lead

PC12 pheochromocytoma cell

PCR polymerase chain reaction

PCV packed cell volume

PDE phosphodiesterase

PDGF platelet-derived growth factor

PDI Psychomotor Development Index

PEC probable effect concentration

PEF expiratory peak flow

PG prostaglandin (e.g., PGE 2 

# , PGF 2 

# ); prostate gland

PHA phytohemagglutinin A

Pi inorganic phosphate

PIXE particle induced X-ray emission

PKC protein kinase C

pl NEpi plasma norepinephrine

PMA progressive muscular atrophy

PMN polymorphonuclear leucocyte

PMR proportionate mortality ratio

PN postnatal (day)

P5N pyrimidine 5'-nucleotidase

PND postnatal day

p.o., PO per os (oral administration)

POMS Profile of Mood States

ppb parts per billion

# II-xxxix ppm parts per million

PPVT-R Peabody Picture Vocabulary Test-Revised

PRA plasma renin activity

PRL prolactin

PROG progeny counts or numbers

PRR prevalence rate ratio

PRWT progeny weight

PST percent transferrin saturation

PTH parathyroid hormone

PTHrP parathyroid hor mone-related protein

PVC polyvinyl chloride

PWM pokeweed mitogen

PRWT progeny weight

QA/QC quality assura nce/quality control

Q/V flux of air (Q) divided by volume of culture (V)

r Pearson correlation coefficient

R 2 

# multiple correlation coefficient

r 2 

# correlation coefficient

226 

# Ra most stable isotope of radium

R/ALAD ratio of ALAD activity be fore and after reactivation

RAVLT Rey Auditory Verbal Learning Test

86 

# Rb rubidium-86 radionuclide

RBA relative bioavailablity

RBC red blood cell; erythrocyte

RBF renal blood flow

RBP retinol binding protein

RBPH reproductive behavior

RCPM Ravens Colored Progressive Matrices

REL rat epithelial (cells)

REP reproduction

RHIS reproductive organ histology

222 

# Rn most stable isotope of radon

RNA ribonucleic acid

ROS reactive oxygen species

ROS 17.2.8 rat osteosarcoma cell line

# II-xl RPMI 1640 Roswell Park Memorial In stitute basic cell culture medium

RR relative risk; rate ratio

RT reaction time

RSEM resorbed embryos

RSUC reproductive success (general)

RT reproductive tissue

∑ SEM sum of the molar concentrations of simultaneously extracted metal

SA7 simian adenovirus

SAB Science Advisory Board

SAM S -adenosyl-L-methionine

SBIS-4 Stanford-Binet Intelligence Scale-4th edition

s.c., SC subcutaneous

SCAN Test for Auditory Processing Disorders

SCE selective chemical extraction; sister chromatid exchange

SCP stripping chronopotentiometry

SD Spraque-Dawley (rat); standard deviation

SDH succinic acid dehydrogenase

SDS sodium dodecyl sulfate; Symbol Digit Substitution

SE standard error; standard estimation

SEM standard error of the mean

SES socioeconomic status

sGC soluble guanylate cyclase

SH sulfhydryl

SHBG sex hormone binding globulin

SHE Syrian hamster embryo cell line

SIMS secondary ion mass spectrometry

SIR standardized incidence ratio

SLP synthetic leaching procedure

SM sexually mature

SMAV species mean acute value

SMR standardized mortality ratio

SNAP Schneider Neonatal Assessment for Primates

SNP sodium nitroprusside

SO 2 

# sulfur dioxide

SOD superoxide dismutase

# II-xli SOPR sperm-oocyte penetration rate

SPCL sperm cell counts

SPCV sperm cell viability

SQGs sediment quality guidelines

SRA Self Reported Antisocial Behavior scale

SRD Self Report of Delinquent Behavior

SRIF somatostatin

SRM Standard Reference Material

SRT simple reaction time

SSADMF Social Security Admini stration Death Master File

SSB single-strand breaks

SSEP somatosensory-evoked potential

StAR steroidogenic acute regulatory protein

STORET STOrage and RETrieval

SVC sensory conduction velocity

SVRT simple visual reaction time

T testosterone

TA tail

TABL time-averaged blood lead

T&E threatened and endangered (species)

TAT tyrosine aminotransferase

TB tibia

TBARS thiobarbituric acid-reactive species

TBPS Total Behavior Problem Score

TCDD methionine-choline-deficient diet

T cell T lymphocyte

TCLP toxic characteristic leaching procedure

TE testes

TEC threshold effect concentration

TEDG testes degeneration

TEL tetraethyl lead

TES testosterone

TEWT testes weight

TF transferrin, translocation factor

TG 6-thioguanine

# II-xlii TGF transforming growth factor

TH tyrosine hydroxylase

232 

# Th stable isotope of thorium-232

TLC Treatment of Lead-exposed Children (study)

TNF tumor necrosis factor (e.g., TNF- α )

TOF time-of-flight

tPA plasminogen activator

TPRD total production

TRH thyroid releasing hormone

TRV toxicity reference value

TSH thyroid stimulating hormone

TSP triple-super phosphate

TT3 total triiodothyronine

TT4 serum total thyroxine

TTES total testosterone

TTR transthyretin

TU toxic unit

TWA time-weighted average

TX tromboxane (e.g., TXB 2 

# )

U uriniary

235 

# U, 238 

# U uranium-234 and -238 radionuclides

UCP urinary coproporphyrin

UDP uridine diphosphate

UNECE United Nations Economic Commission for Europe

Ur urinary

USFWS U.S. Fish and Wildlife Service

USGS United States Geological Survey

UV ultraviolet

V79 Chinese hamster lung cell line

VA Veterans Administration

VC vital capacity; vitamin C

VDR vitamin D receptor

VE vitamin E

VEP visual-evoked potential

VI variable-interval

# II-xliii vit C vitamin C

vit E vitamin E

VMA vanilmandelic acid

VMI Visual-Motor Integration

VSM vascular smooth muscle (cells)

VSMC vascular smooth muscle cells

WAIS Wechsler Adult Intelligence Scale

WDS wavelength dispersive spectrometers

WHO World Health Organization

WISC Wechsler Intelligence Scale for Children

WISC-R Wechsler Intelligence Scale for Children-Revised

WO whole organism

WRAT-R Wide Range Achievement Test-Revised

WT wild type

WTHBF-6 human liver cell line

ww wet weight

XAFS X-ray absorption fine structure

XANES X-ray absorption near edge spectroscopy

XAS X-ray absorption spectroscopy

XPS X-ray photoelectron spectroscopy

X-rays synchrotron radiation

XRD X-ray diffraction

XRF X-ray fluorescence

ZAF correction in reference to thr ee components of matrix effects:
atomic number (Z), absorpti on (A), and fluorescence (F)

ZnNa 2 

# DTPA zinc disodium diet hylenetriaminepentaacetic acid

ZnNa 2 

# EDTA zinc disodium ethyl enediaminetetraacetic acid

ZPP zinc protoporphyrin

# AX7-1 

# AX7. CHAPTER 7 ANNEX - ENVIRONMENTAL

EFFECTS OF LEAD

AX7.1 TERRESTRIAL ECOSYSTEMS

AX7.1.1 Methodologies Used in Terrestrial Ecosystems Research

The distribution of Pb throughout the terrestrial ecosystem, via aerial deposition, has been

discussed throughout this document. Its further impacts on soil, sediment, and water provide

numerous pathways that may promote unacceptable risk to all levels of biota. Stable isotopes of

Pb have been found useful in identifying sources and apportionment to various sources. One of

the key factors affecting assessment of risk is an understanding, and pe rhaps quantification, of

bioavailability. Therefore, the bioavailability of Pb is a key issue to the development of

NAAQS. However, the discussion of all methods used in characterizi ng bioavailability is

beyond the scope of this chapter. The following topics are discussed in this chapter.

• Lead Isotopes and Apportionment

• Methodologies to determine Pb speciation

• Lead and the Biotic Ligand Model (BLM)

• In situ methods to reduce Pb bioavailability

AX7.1.1.1 Lead Isotopes and Apportionment

Determination of the extent of Pb contamin ation from an individual source(s) and its

impact are of primary importance in risk assessm ent. The identification of exposure pathway(s)

is fundamental to the risk anal ysis and critical in the planni ng of remediation scenarios.

Although societies have been consuming Pb fo r nearly 9,000 years, production of Pb in

the United States peaked in 1910 and 1972, at ap proximately 750 and 620 kt/year, respectively

(Rabinowitz, 2005). The diversity of potential Pb sources (fossil fuel burning, paint pigments,

gasoline additives, solders, ceramics, batteries ) and associated production facilities (mining,

milling, smelting-refining) make fingerprinting of sources difficult. (See Chapter 2 and its

Annex for additional information on sources.) Therefore, dealing with multiple sources (point

and nonpoint), a reliable and speci fic fingerprinting technique is required. It has been well

established (Sturges and Barrie, 1987; Rabinowitz, 1995) that the stable isotope composition of

# AX7-2 Pb is ideally suited for this task. Lead isotopic ratio differences often allow multiple sources to

be distinguished, with an apportionment of the bulk Pb concentration made to those sources.

Lead has four stable isotopes: 204 

# Pb, 206 

# Pb, 207 

# Pb, and 208 

# Pb in natural abundances of 1.4,

24.1, 22.1, and 52.4%, respectively. The radiogenic 206 

# Pb, 207 

# Pb, and 208 

# Pb are produced by

radioactive decay of 238 

# U, 235 

# U, and 232 

# Th, respectively. Thus, the isotopic composition of Pb

varies based on the U:Pb and Th:Pb ratios of th e original ore’s source and age (Faure, 1977).

Because of the small fractional mass differences of the Pb isotopes, ordinary chemical and

pyrometallurgical reactions will not alter their original composition. Therefore, anthropogenic

sources reflect the isotopic composition of the ores from which the Pb originated.

To acquire the Pb isotopes, a sample, gene rally in aqueous form, is analyzed on an

ICP/MS (quadrapole, magnetic sector, or time-o f-flight). Studies reviewing the most common

analytical and sample preparati on procedures include Ghazi and Millette (2004), Townsend et al.

(1998), and Encinar et al. (2001a,b) . The correction factor for mass discrimination biases is

generally made by analyzing the National In stitute for Standards and Technology (NIST),

Standard Reference Material (SRM) 981 and/or spiked 203 

# Tl and 205 

# Tl isotopes (Ketterer et al.,

1991; Begley and Sharp, 1997). The overall success of Pb isotope fingerprinting is generally

dependent on analysis precision, which in turn depends on the type of mass analyzer used

(Table AX7-1.1.1).

Table AX7-1.1.1. Relative Standard Deviation (RSD) for Lead Isotope
Ratios on Selected Mass Spectrometers

RSD Quadrapole Double-Focusing Single-Focusing
Magnetic Sector High-Resolution
Magnetic Sector

ICP/MS

204 

# Pb: 206 

# Pb 0.0031 0.0032 0.00053 0.0011

207 

# Pb: 206 

# Pb 0.0032 0.0027 0.00053 0.00048

208 

# Pb: 206 

# Pb 0.0026 0.0024 0.00053 0.00046



# An extensive database comprising primarily No rth American Pb sources can be assembled

from Doe and Rohrbough (1977), Doe and Stacey (1974) , Doe et al. (1968), Heyl et al. (1974),

# AX7-3 Leach et al. (1998), Stacey et al. (1968), Zartman (1974), Cannon and Pierce (1963), Graney

et al. (1996), Unruh et al . (2000), James and Henry ( 1993), Rabinowitz (2005), and

Small (1973).

The use of Pb isotopes to quantitatively appor tion source contributions follows the simple

mixing rule when only two sources are possible (Faure, 1977). Once multiple sources need to be

considered, a unique solution can no longer be calculated (Fry and Sherr, 1984). Phillips and

Gregg (2003) have designed a model to give feasible source contributions when multiple sources

are likely. Many studies have demonstrated the usefulness of this apportionment technique.

Media of all types have been st udied: water (Flegal et al., 1989a,b; Erel et al., 1991; Monna

et al., 1995), ice (Planchon et al., 2002), dust (Adgate et al., 1998; Sturges et al., 1993), and

soil/sediments (Hamelin et al., 1990; Farmer et al ., 1996; Bindler et al., 1999; Haack et al., 2004;

Rabinowitz and Wetherill, 1972; Rabi nowitz, 2005; Kettere r et al., 2001).

AX7.1.1.2 Speciation in Assessing Lead Bioava ilability in the Terres trial Environment

One of the three processes defined by the National Research Council in its review on

bioavailability (NRC, 2002) is “contaminant in teractions between phases”, more commonly

referred to as “speciation.”

A wide variety of analytical (XRD, EP MA, EXAFS, PIXE, XPS, XAS, SIMS) and

chemical speciation modeling (SOILCHEM, MINTEQL, REDEQL2, ECOSAT, MINTEQA2,

HYDRAQL, PHREEQE, WATEQ4F) t ools have been used to char acterize a metal’s speciation

as it is found in various media. Currently, for risk assessment purposes (not considering

phytotoxicity), where large sites with numerous media, pathways, and metals must often be

characterized in a reasonable time frame, electron microprobe analysis (EMPA) techniques

provide the greatest information on metal speciati on. Other techniques such as extended X-ray

absorption fine structure (EXAFS) and extended X-ray absorption near edge spectroscopy

(EXANES) show great promise and will be import ant in solving key mechanistic questions.

In the case of phytotoxicity, the speciation of me tals by direct measurement or chemical models

of pore-water chemistry is most valuable. Fu rther work needs to be done in developing

analytical tools for the speciation of the methyl -forming metals (Hg, As, Sb, Se, and Sn) in soils

and sediments.

# AX7-4 Concept

For a given metal or metalloid (hereafter referred to as metal), the term speciation refers

to its chemical form or species, including its phys icochemical characteristics that are relevant to

bioavailability. As a result of the direct im pact these factors often have on a metal’s

bioavailability, the term “bioaccessibility” ha s been adopted to define those factors.

Speciation Role

The accumulation of metals in the lithosphe re is of great concern. Unlike organic

compounds, metals do not degrade and, thus, have a greater tendency to bioaccumulate. It is

now well accepted that knowledge of the bulk, toxic characteris tic leaching procedure (TCLP),

or synthetic leaching procedure (SLP) concentrations for any metal is not a controlling factor in

understanding a metal’s environmental behavior or in developing remedies for its safe

management. Although these tests are essential to site characterization and management, they

offer no insight into risk assessment. Rather, it is the metal’s bioavailabil ity (the proportion of a

toxin that passes a physiological membrane [the pl asma membrane in plants or the gut wall in

animals] and reaches a target receptor [cytosol or blood]), which plays a significant role in the

risk assessment of contaminated media.

The NRC review (NRC, 2002) on bioavailability defined bioavailability processes in

terms of three key processes:

• contaminant interactions be tween phases (association- dissociation/bound-released),

• transport of contaminants to organism, and

• passage across a physiological membrane.

As mentioned previously, the first process is more commonl y referred to as speciation.

The speciation of a toxic metal in the environm ent is a critical com ponent of any ecosystem

health risk assessment. Four important toxi cologic and toxicokinetic determinants relating

speciation to bioavailability are the (1) chemical form or species, (2) part icle size of the metal

form, (3) lability of the ch emical form, and (4) source.

# AX7-5 Chemical Form of Species

The solid phase in a medium controls the activity of a metal in solution, whether the

solution is surface, ground, or pore water or GI fluids, and plays a profound role in metal

bioavailability. This is perhaps best illustrated by in vivo and in vitro results for many of the

common Pb-bearing minerals (D rexler, 1997) (Figure AX7-1.1.1). The metal species found in

media are often diverse, and data suggest that their bioavailability may be significantly

influenced by site-specific variations within th ese identified metal speci es (Davis et al., 1993;

Ruby et al., 1992; Drexler and Mushak, 1995).

Figure AX7-1.1.1. Relationship of bioaccessibili ty (low, medium, high) versus speciation
as shown with scanning electron micrographs of various Pb-bearing

materials.

Particle Size of Metal Species

Particle size of a metal form is an important factor in the mobilization of the metal,

primarily because as size decreases, the surface area of the particle increases, thereby increasing

solubility. Thus, although solubi lity is not the only control fo r bioavailability, an increase in

bioavailability has been directly attributed to a decrease in pa rticle size: Barltrop and Meek

# AX7-6 (1979) observed that “the smaller the lead pa rticle, the higher blood lead level.” Similar

observations were made by Healy et al. (1992) using and an in vitro dissolution technique.

Drexler (1997) presented in vi tro results on numerous Pb-bearing phases ranging in particle size

from 35 to 250 μm. While all phases studied show ed increased bioavailab ility with decreasing

particle size, more significantly, not all forms showed the same de gree or magnitude of change

(Figure AX7-1.1.2). Atmospheric particles are ge nerally found to occur in bimodal populations:

fine; 0.1 to 2.5 μm and coarse; 2.5 to 15 μm. This distribution is bot h a function of there

transport mechanism and emission source. Although the upper size limit for particles that can be

suspended in air is about 75 μm (Cowherd et al ., 1974), other means of mechanical entrainment

(saltation, and creep) can transpor t particles as large as 1000 μm , supporting the importance of

fugative emissions on media contamination. In addition, particle size can change post

depositional, as soluble forms re-precipitate or sorb onto other surfaces. Limited data are

available on the particle-size of discrete Pb phases from multimedia environments. One example

is the study by Drexler, 2004 at Herculaneum, Miss ouri. At this site, galena (PbS) was the

dominant Pb species with mean particle-s ize distributions of 4, 6, and 14 μm in PM 10 

# filters,

house dust, and soils, respectively. These findings support the conclusion that aerial transport

was the primary mechanism for Pb deposition in resi dential yards. Finally, such laboratory data

have been supported by extensive epidemiologic evidence, enforci ng the importance of particle

size (Bornschein et al., 1 987; Brunekreef et al., 1983; Angle et al., 1984).

Particle Lability

The impact on bioavailability of a metal partic le’s lability (its associations within the

medium matrix) is not well documented, but it follows the premise put forth by many of the

developing treatment technologies regarding its being bound or isol ated from its environment.

Data from several EPA Superfund sites and th e Region VIII swine study (U.S. Environmental

Protection Agency, 2004a) suggest that matrix asso ciations, such as liberated versus enclosed,

can play an important part in bioavailability. As illustrate d in Figure AX7-1.1.3, two different

media with similar total Pb concentrations a nd Pb forms (slag, Pb-oxide, and Pb-arsenate)

exhibit significantly different bioavailabilities. In the Murray, UT sample (bioaccumulation

factor [BAF] = 53%), a greater fraction of the more bioavailable Pb-oxides are liberated and

not enclosed in the less-soluble glass-like slag as observed in the Leadville, CO sample

# AX7-7 Figure AX7-1.1.2. Variation of bioavailability with particle size.

(BAF = 17%). Other evidence is more empiri cal, as illustrated in Figure AX7-1.1.4, where a

large particle of native Pb is shown to have developed a weathering ring of highly bioavailable

Pb-chloride and Pb-oxide. Such observations ca n be useful in understanding the mechanistic

phenomena controlling bioavailability. In additi on, they will aid in developing and validating

models to predict metal-e nvironment interactions.

# AX7-8 Figure AX7-1.1.3. Illustration of particle lability and bioavailab ility at two different sites

with similar total Pb concentrations and Pb forms.

Figure AX7-1.1.4. Scanning electron micrograph of a large native Pb particle showing
outer ring of highly bioavaila ble Pb-chloride and Pb-oxide.

# AX7-9 Source

Although the source of a metal is not directly related to bioavailability, it plays an

important role in risk assessment with the evaluation of metal (1) pathways, (2) background,

and (3) apportionment. It is important to understand a metal’s pathway before any remedial

action can be taken; otherwise, recontamina tion of the primary pathway and reexposure can

occur. Knowledge of background is important, as an action level cannot be established below

natural background levels.

Plants

When considering the bioavailabil ity of a metal to plants from soils and sediments, it is

generally assumed that both the kinetic rate of su pply and the speciation of the metal to either the

root or shoot are highly important. In soils and sediments generally, only a small volume of

water is in contact with the chemical form, and although the proportion of a metal’s

concentration in this pore water to the bulk soil/s ediment concentration is small, it is this phase

that is directly availabl e to plants. Therefore, pore water chemistry (i.e., metal concentration as

simple inorganic species, organic complexes, or colloid complexes) is most important.

Tools currently used for metal speciation fo r plants include (1) in-situ measurements

using selective electrodes (Gundersen et al., 199 2; Archer et al., 1989; Wehrli et al., 1994);

(2) in-situ collection techniques using diffusive equilibrium thin films (DET) and diffusive

gradient thin films (DGT) followed by laborator y analyses (Davison et al., 1991, 1994; Davison

and Zhang, 1994; Zhang et al., 1995); and (3) equilibrium models ( SOILCHEM) (Sposito and

Coves, 1988).

AX7.1.1.3 Tools for Bulk Lead Quantification and Speciation

Bulk Quantification

The major analytical methods most commonly us ed for bulk analyses outlined in the 1986

Lead ACQD included:

• Atomic Absorption Spectrometry (AAS)

• Emission Spectrometry (Inductively coupled plasma/atomic emission spectrometry)

• X-ray Fluorescence (XRF)

• Isotope Dilution Mass Spectrometry (ID/MS)

# AX7-10 • Colorimetric

• Electrochemical (anodic stri pping voltametry and differe ntial pulse polarography).

The choice of analytical method today for bul k quantification is generally ICP/AES or

ICP/MS (U.S. Environmental Protection Ag ency, 2001). Since 1986, numerous SRMs have

been developed for Pb (Table AX7-1.1.2), and se veral significant tec hnological improvements

have been developed.

Table AX7-1.1.2. National Institute of Standards and Technology Lead SRMs

NIST SRM Medium Mean Pb mg/kg

2710 Soil 5532

2711 Soil 1162

2709 Soil 18.9

2587 Soil (paint) 3242

2586 Soil (paint) 432

2783 Filter (PM 2.5 

# ) 317

1648 Urban particulate 6550

1649a Urban dust 12,400

2584 Indoor dust 9761

2583 Indoor dust 85.9

1515 Apple leaves 0.47

1575 Pine needles 0.167



# Modern spectrometry systems have replaced photomultiplier tubes with a charge-coupled

device (CCD). The CCD is a camera that can de tect the entire light spectrum (>70,000 lines)

from 160 to 785 nm. This allows for the simultaneous measurement of all elements, as well as

any interfering lines (a productiv ity increase), and increases precis ion. The detection limit for Pb

in clean samples can now be as low as 40 ppb.

# AX7-11 Modern ICP/AES systems offer a choice of e ither axial viewed pl asma (horizontal),

which provides greater sensitivity (DL= 0.8 μg Pb/L ), or radial (vertical) viewed plasma, which

performs best with high total disso lved samples (DL = 5.0 μg Pb/L).

The development of reaction or collision cells have expanded the capabilities of ICP/MS

and lowered detection limits for many elements that were difficult to analyze because of

interferences such as Se, As, Ti, Zn, Ca, Fe, a nd Cr. The cells provide efficient interference

(isobaric, polyatomic, and argi de) removal independent of the analyte and sample matrix by

using various reaction gases (H 2 

# , He, NH 3 

# ), eliminating the need for interference correction

equations.

Speciation Tools

A wide variety of analytical and chemical techniques have be en used to characterize a

metal’s speciation (as defined above) in various media (Hunt et al., 1992; Manceau et al., 1996,

2000a; Welter et al., 1999; Szulcz ewski et al., 1997; Isaure et . al., 2002; Lumsdon and Evans,

1995; Gupta and Chen, 1975; Ma and Uren, 1995; Ch arlatchka et al., 1997). Perhaps the most

important factor that one must keep in mind in selecting a technique is that, when dealing with

metal-contaminated media, one is most often look ing for the proverbial “needle in a haystack.”

Therefore, the speciation technique must not onl y provide the information outlined above, but it

must also determine that information from a medi um that contains very little of the metal.

As illustrated in Figure AX7-1.1.5, for a Pb-contam inated soil, less than 1% (modally) of a

single species can be responsible for a bulk metal’s concentration above an action level. This

factor is even more significant for other metals (i.e., As, Cd, or Hg) were action levels are often

below 100 mg/kg.

Of the techniques tested (physic ochemical, extractive, and theore tical), the tools that have

been used most often to evaluate speciation for particle-bound metal include X-ray absorption

spectroscopy (XAS), X-ray diffraction (XRD), particle induced X-ray emission (PIXE and

μPIXE), electron probe microanalysis (EPMA) , secondary ion mass spectrometry (SIMS),

X-ray photoelectron spectroscopy (XPS), sequential ex tractions, and single chemical extractions.

The tools that have been used most often to evaluate speciation for metal particles in solution

include the following computer-based models : MINTEQL, REDEQL2, ECOSAT, MINTEQA2,

HYDRAQL, PHREEQE, and WATEQ4F. Thes e tools are briefly described below.

# AX7-12 Figure AX7-1.1.5. Bulk lead versus single sp ecies modality. Shade d area represents typical soil-lead concentrations fo und at remediation sites in the

western United States.

Particle-Bound Metal

Direct Approaches

Over the past decade, numerous advances in materials science have led to the

development of a wide range in analytical tool s for the determination of metal concentration,

bonding, and valance of individual particles on a scale that can be considered useful for the

speciation of environmentally important material s (i.e., soils, wastes, sediments, and dust).

This review will provide the reader with a brief description of these techniques, including their

benefits, limitations (cost, avai lability, sample preparation, reso lution), and usability as well as

references to current applications. Although mo st of these tools are scientifically sound and

offer important information on the mechanistic u nderstanding of metal o ccurrence and behavior,

only a few currently provide useful information on metal bioavailability at a “site” level.

However, one may still find other techniques essential to a detailed characterization of a selected

# AX7-13 material to describe the chemical or kinetic f actors controlling a metal’s release, transport,

and/or exposure.

X-Ray absorption Spectroscopy (XAS) . X-ray absorption spectroscopy (XAS) is a

powerful technique using the tunable, monochr omatic (white light) X-rays produced by a

synchrotron (2-4 GeV) to record oscillations in atomic absorption within a few 100 GeV of an

element’s absorption edge. Spectra provide in formation on both chemical state and atomic

structure. Measurements are theoretically availa ble for all elements and are not surface-sensitive

nor sample-sensitive (i.e., gases, liquids, so lids, and amorphous mate rials are testable).

High-energy spectra within 30 eV of the edge, termed XANES (X-ray absorption near

edge structure spectroscopy (Fendorf et al., 1994; Maginn, 1998), are particularly suited for

determination and quantification (10 to 100 ppm ) of metal in a part icular oxidation state

(Szulczewski et al., 1997; Sha ffer et al., 2001; Dupont et al., 2002). The lower-energy spectra

persist some 100 eV above the edge. These os cillations are termed EXAFS (extended X-ray

absorption fine structure) and are more commonl y used for speciation analyses (Welter et al.,

1999; Manceau et al., 1996, 2000a; Isaure et al., 2002).

The main limitations to XAS techniques are (1 ) the lack of spatial resolution; (2) XAS

techniques provide only a wei ghted average signal of structural configurations, providing

information on the predominant form of the metal, while minor species, which may be more

bioavailable, can be overlooked; (3) access to sync hrotrons is limited and the beam time required

to conduct a site investigation would be prohibitive; (4) a la rge spectral library must be

developed; (5) generally, poor fits to solution models are achieved when the compound list is

large; and (6) high atomic number elements ha ve masking problems based on compound density.

X-Ray Diffraction (XRD). In X-ray diffraction, a monochromatic Fe, Mo, Cr, Co, W, or

Cu X-ray beam rotates about a finely powdered sample and is reflected off the interplanar

spacings of all crystalline compounds in the sample, fulfilling Bragg’s law (n λ = 2dsin θ ). The

identification of a species from this pattern is based upon the position of the lines (in terms of

θ or 2 θ ) and their intensities as recorded by an X-ray detector. Th e diffraction angle (2 θ ) is

determined by the spacing between a particular set of atomic planes . Identification of the species

is empirical, and current available da tabases contain more than 53,000 compounds.

If a sample contains multiple compounds, interpretation becomes more difficult and

computer-matching programs are essential. In some instances, by measuring the intensity of the

# AX7-14 diffraction lines and comparing them to standa rds, it is possible to quantitatively analyze

crystalline mixtures; however, if the species is a hydrated form or has a preferred orientation,

this method is only semiquantitative at best. Si nce this technique repr esents a bulk analysis,

no particle size or lability informati on can be extracted from the patterns.

Particle Induced X-Ray Emission (PIXE and μPIXE). Particle induced X-ray emission

(PIXE) uses a beam, ~4 μm in diameter, of heav y charged particles (gener ally He) to irradiate

the sample. The resulting characteristic X-rays are emitted and detected in a similar manner as

XRF, using Si-Li detectors. Pa rticles generated from a small accel erator or cyclotron, with a

potential of 2 to 4 MeV, are commonly used. Detection limits on the order of 1 mg/kg are

achieved on thin-film samples. Disadvantages to its use for speciation include (1) only a small

volume of material can be analyzed (1 to 2 mg/cm 2 

# ); (2) no particle size information is provided;

(3) peak overlaps associated with Si-Li dete ctors limit identification of species; (4) limited

availability; and (5) high cost. For a further review of PIXE analysis and applications, see

Maenhaut (1987).

Electron Probe Microanalysis (EPMA) . Electron probe microanalysis uses a finely

focused (1 μm) electron beam (generated by an electron gun operating at a 2 to 30 kV

accelerating voltage and pico/nanoamp currents) to produce a combination of characteristic

X-rays for elemental quantifica tion along with secondary electrons and/or backscatter electrons

for visual inspection of a sample. Elements fr om beryllium to uranium can be nondestructively

analyzed at the 50-ppm level with limited samp le preparation. X-ray spectra can be rapidly

acquired using either wavelengt h dispersive spectrometers (WDS) or energy dispersive

spectrometers (EDS).

With WDS, a set of diffracting crystals, of known d-spacing, revolve in tandem with a

gas-filled proportional counter insi de the spectrometer housing so that Bragg’s law is satisfied

and a particular wavelength can be focused. P hoton energy pulses reflecting off the crystal are

collected for an individual elemental line by the counter as a fi rst approximation to

concentration. For quantitative analysis, these intensities ar e compared to those of known

standards and must be corrected for background, dead time, and elemental interactions (ZAF)

(Goldstein et al., 1992). ZAF co rrection is in reference to th e three components of matrix

effects: atomic number (Z), ab sorption (A), and fluorescence (F).

# AX7-15 With EDS, a single Si-Li crystal detector is used in conjunction with a multichannel

analog-digital converter (ADC) to sort electrical pulses (with he ights approximately proportional

to the quantum energy of the photon that gene rated them), producing a spectrum of energy

(wavelength) versus counts. The net area under a particular peak (element al line) is proportional

to its concentration in the sample. For quantitativ e analyses, corrections similar to WDS analysis

must be performed. Although EDS detectors are more efficient than WDS, detection limits are

significantly greater (~1000 ppm), because of elevated backgrounds and peak overlaps.

For speciation analysis, the EDS system must NEVER be used as the primary detector, as

numerous errors in species identification are often made. These are generally the result of

higher-order X-ray line overlaps.

This technique has been routinely used for site characterizations (Linton et al., 1980;

Hunt et al., 1992; Camp, Dresser, and McKee (CDM), 1994; U.S. Environmental Protection

Agency, 2002). Currently this technique offers the most complete data package on metal

speciation than any of the other tools. The method is relative ly fast and inexpensive, available,

and provides all of the required information for bi oavailability assessment s (i.e., particle size,

species, lability, and sourcing). A number of limitations still need to be addressed including:

(1) its inability to quickly isolate a statistically significant population of particles in soils with

low bulk metal concentrations (<50 mg/kg), meaning that for some metals with low

concentrations of concern (i.e., Cd, Mo, Sb, Se), this method may be less useful; (2) the more

volatile metals (i.e., Hg, Tl) ar e often volatilized under the electron beam or lost during sample

preparation.

Secondary Ion Mass Spectrometry (SIMS). Secondary ion mass spectrometry (also known

as ion microprobes or ion probes) is a well-known technique, primarily surface focused, that uses

a 0.5 to 20 kV O, Ar, Ga, In, or Cs ion beam in bombarding (sputtering) the surface of a sample

while emitting secondary ions that are detected by either quadrapole, tim e-of-flight (TOF), or

magnetic sector mass spectrometers. Sensitivity is very high, in the ppb range for elements

hydrogen to uranium, providing quantitative results on elemental or isotopic metals and organic

compounds. With the advent of liquid metal (In and Ga) ion beam s, beam sizes of less than

1 μm are possible, although 20 μm is more commonly used.

# AX7-16 The major disadvantage of SIMS to species id entification is that each element or isotope

must be tuned and analyzed sequentially. This makes the identification of a metal form highly

time-consuming and, thus, the characterizati on of a multiphase medium impractical.

X-Ray Photoelectron Spectroscopy (XPS). X-ray photoelectron spectroscopy or ESCA

(electron spectroscopy for chemical analysis, as it was previously known) is a classical surface,
10 to 50 Å in depth, analytical technique for dete rmining qualitative elemental concentrations of

elements greater than He in atomic number and provides limited structural and oxidation state

information. In XPS, the high-energy (15 kV) electrons are typically produced from a dualanode (Al-Mg) X-ray tube. The ex citation or photoionization of atom s within the n ear surface of

the specimen emit a spectrum of photoelectrons. The measured binding energy is characteristic

of the individual atom to which it was bound. Monochromatic sources are often employed to

improve energy resolution, allowing one to infer oxidation states of elements or structure of

compounds (organic and inorganic) by means of small chemical shifts in binding energies

(Hercules, 1970). The major disadvantages of XPS for environmental speciation studies is its

poor sensitivity, especially in complex matrices and its large, 100-200 μm , spatial resolution.

The direct speciation techniques discusse d above are summarized in Table AX7-1.1.3.

Indirect Approaches

A more indirect approach to speciation than the methods previously described include the

functional or operational extracti on techniques that have been used extens ively over the years

(Tessier et al., 1979; Tessier and Campbell, 198 8; Gupta and Chen, 1975). These methods use

either a single or sequential ex traction procedure to release speci es associated with a particular

metal within the media. Single chemical extr actions are generally used to determine the

bioavailable amount of metal in a functional class: water-sol uble, exchangeable, organically

bound, Fe-Mn bound, or insoluble.

In a similar approach, sequential extractions tr eat a sample with a succession of reagents

intended to specifically dissolve different, less av ailable phases. Many of these techniques have

been proposed, most of which are a variation on the classical method of Tessier et al. (1979),

in which metal associated with exchang eable, carbonate-bound, Fe-Mn bound, organically

bound, and residual species can be determined. Beckett (1989), Kheboian and Bauer (1987),

and Foerstner (1987) provide excellent reviews on the use and abuse of extractions. These

# AX7-17Table AX7-1.1.3. Characteristicsfor Direct Speciation TechniquesTools Species Lability Species Particle Size Species Valance State Species Bonding Species Composition Species Abundance Element Specificity Isotopic Character Element Sensitivity Resolution Availability CostXRD No No No No No# No No No 3-4 vol% Bulk 1 $EMPA Yes Yes Yes+ No Yes Yes? B-U No*** 50 ppm 0.5-1 μm 2 $$SIMS No Yes No No Yes* Yes** Li-U Yes 1 ppb 10 μm 4 $$$XPS No No Yes Yes Yes* Yes** H-U No wt.% 100 μm 2 $$XAS No No Yes Yes Yes* Yes** He-U No ppb 2 μm 5 $$$$PIXIE No No No No Yes Yes** B-U No 10 ppm 4 μm 4 $$$$* Technique requires each element be tuned and standardized, requiring unreasonable time limits.** Techniques designed and tested only on simple systems. Multiple species require lengthy analytical times and data reduction.*** Limited when combined with ICP/MS/LA.# Identifies crystalline compounds andstoichiometric compositions only.? Technique has limitations based on particle counting statistics.+ Valance determined by charge balance of complete analyses.

# AX7-18 techniques can be useful in a study of metal uptake in plants, where transfer takes place

predominately via a solution pha se. However, one must keep in mind that they are not

“selective” in metal species, give no particle size information and, above all, these leachable

fractions have never been co rrelated to bioavailability.

Solution Speciation Using Computer-Based Models. Computer-based models are either

based upon equilibrium constant s or upon Gibb’s free energy valu es in determining metal

speciation from solution chemistry conditions (c oncentration, pH, Eh, organic complexes,

adsorption/desorption sites, and temperature). Bo th approaches are subject to mass balance and

equilibrium conditions. These models have under gone a great deal of development in recent

years, as reliable thermodynamic data has beco me available and can provide some predictive

estimates of metal behavior. A good review of th ese models and their applications is provided

by Lumsdon and Evans (1995).

Speciation can be controlled by simple reacti ons; however, in many cases, particularly in

contaminated media, their state of equilibrium and reversibility are unknown. In addition, these

models suffer from other limitations such as a lack of reliable thermodynamic data on relevant

species, inadequacies in models to correct for high ionic streng th, reaction kinetics are poorly

known, and complex reactions with co-precipitation/adsorption are not modeled.

The first limitation is perhaps the most significant for contaminated media. For example,

none of the models would predic t the common, anthropogenic, Pb phases, i.e., paint, solder,

and slag.

AX7.1.1.4 Biotic Ligand Model

The biotic ligand model (BLM) is an equilibr ium-based conceptual model that has been

incorporated into regulatory agencies guidelines (i ncluding the EPA) to predict effects of metals

primarily on aquatic biota and to aid in the unde rstanding of their intera ctions with biological

surfaces (see Annex Section AX7.2.1.3).

Because of assumed similarities in mechanisms of toxicity between aquatic and terrestrial

organisms, it is likely that the BLM approach as developed for the aquatic compartment may also

be applicable to the terrestrial environment. Recent research has been directed toward extending

the BLM to predict metal toxicity in soils (Steenbergen et al., 2005). Steenbergen et al. (2005)

pointed out that, until recently, the BLM concept ha s not been applied to predict toxicity to soil

# AX7-19 organisms. The authors believe there may be two reasons for this. First, metal uptake routes in

soils are generally more complex than those in water, because exposure via pore water and

exposure via ingestion of soil particles may, in pr inciple, both be important. Second, it remains

very difficult to univariately control the co mposition of the soil pore water and the metal

concentrations in the pore water, due to re-e quilibration of the system following modification of

any of the soil properties (inc luding addition of metal salts).

Steenbergen et al. (2005) assessed acute copper toxi city to the earthworm Aporrectodea

caliginosa using the BLM. To overcome the aforemen tioned problems inherent in soil toxicity

tests they developed an artificia l flow-through exposure system consisting of an inert quartz sand

matrix and a nutrient solution, of which the co mposition was univariately modified. Thus, the

obstacles in employing the BLM to terrestrial ecosystems seem to be surmountable, and future

research may provide useful information on Pb bioavailability and toxi city to terrestrial

organisms.

AX7.1.1.5 Soil Amendments

The removal of contaminated soil to mitigate exposure of terrestrial ecosystem

components to Pb can often present both economic and logistic problems. Because of this,

recent studies have focused on in situ methodol ogies to lower soil-Pb RBA (Brown et al.,

2003a,b). To date, the most common methods studi ed include the addition of soil amendments

in an effort either to lower the solubility of the Pb form or to provide sorbtion sites for fixation of

pore-water Pb. These amendments typically fa ll within the categories of phosphate, biosolid,

and Al/Fe/Mn-oxide amendments.

Phosphate Amendments

Phosphate amendments have been studied exte nsively and, in some cases, offer the most

promising results (Brown et al., 1999; Ryan et al., 2001; Cotter-Howells and Caporn, 1996;

Hettiarachchi et al., 2001, 2003; Rabinowitz, 1993; Ya ng et al., 2001; Ma et al., 1995). Research

in this area stems from early work by Nria gu (1973) and Cotter-Howells and Caporn (1996), who

pointed out the very low solubili ties for many Pb-phosphates (Ksp ! 27 to ! 66), particularly

chloropyromorphite [Pb 5 

# (PO 4 

# ) 3 

# Cl]. The quest to transform sol uble Pb mineralogical forms into

chloropyromorthite continues to be the primary focus of most studies. Sources of phosphorous

# AX7-20 have included phosphoric acid (H 3 

# PO 4 

# ), triple-super phosphate (TSP) , phosphate rock, and/or

hydroxyapatite (HA). Various studi es have combined one or more of these phosphorous sources

with or without lime, iron, and/or manganese in an attempt to enhance amendment qualities.

Most amendments are formulated to cont ain between 0.5 and 1.0% phosphorous by weight.

They are then either applied wet or dry and then mixed or left unmixed with the contaminated

soil. Success of phosphate amendments has been variable, and the degree of success appears to

depend on available phosphorous and the dissolu tion rate of the original Pb species.

A number of potentially signi ficant problems associated with phosphate amendments have

been recognized, including both phyto- and earthw orm toxicity (Ownby et al., 2005; Cao et al.,

2002; and Rusek and Marshall, 2000). Both of these toxicities are primarily associated with very

high applications of phosphorous and/or decreased soil pH. Indications of phytotoxicity are

often balanced by studies such as Zhu et al. (200 4) that illustrate a 50 to 70% reduction in shootroot uptake of Pb in phosphate-amended soils. Additionally, the added phosphate poses the

potential risk of eutrophication of nearby waterways from soil runoff. Finally, Pb-contaminated

soils from the extractive metals industry or agricultural sites often have elevated concentrations

of arsenic. It has been s hown (Impellitteri, 2005; Smith et al., 2002; Chaney and Ryan, 1994;

and Ruby et al., 1994) that the addition of phosphate to such soils would enhance arsenic

mobility (potentially moving arsenic down in to the groundwater) through competitive anion

exchange. Some data (Lenoble et al., 2005) indi cate that if one coul d amend arsenic and Pb

contaminated soils with iron(III) phosphate this problem can be mitigated, however the increased

concentrations of both phosphate an d iron still exclude th e application when drinking water is an

issue.

Biosolid Amendments

Historically, biosolids have been used in th e restoration of coal mines (Haering et al.,

2000; Sopper, 1993). More recently, workers have demonstrated the feasib ility of their use in

the restoration of mine tailings (Brown et al., 2003a), and ur ban soils (Brown et al., 2003b;

Farfel et al., 2005). Mine tailings are inherently difficult to remedi ate in that they pose numerous

obstacles to plant growth. They are most often (1) acidic; (2) high in metal content, thus prone to

phytotoxicity; (3) very low in organic content; and (4) deficient in macro- and micronutrients.

# AX7-21 Stabilization (i.e., the establishment of a vegetativ e cover) of these environments is essential to

the control of metal exposure or migration from soil/dust and groundwater pathways.

At Bunker Hill, ID, Brown et al. (2003b) de monstrated that a mixture of high nitrogen

biosolids and wood pulp or ash, when surface applied at a rate of approximately 50 and

220 tons/ha, respectively, increased soil pH from 6.8 to approximately 8.0, increased plant

biomass from 0.01 mg/ha to more than 3.4 tons/ha, and resulted in a heal thy plant cover within

2 years. Metal mobility was more difficult to eval uate. Plant concentrations of Zn and Cd were

generally normal for the first 2 years of the study; however, Pb concentrations in vegetation

dramatically increased two to three times in the first year. Additionally, macronutrients (Ca, K,

and Mg) decreased in plant tissue.

Urban soils, whether contaminated from smelting, paint, auto emissions, or industrial

activity, are often contaminated with Pb (Agenc y for Toxic Substances and Disease Registry

[ATSDR], 1988) and can be a sign ificant pathway to elevated child blood Pb levels (Angle et al.,

1974). Typically, contaminated residential soils are replaced under Superfund rules. However,

urban soils are less likely to be remediated un less a particular facility is identified as the

contaminate source. Application of biosolids to such soils may be a cost-effective means for

individuals or communities to lower Pb RBAs.

A field study by Farfel et al. (2005) using the commercia l biosolid ORGO found that,

over a 1-year period, Pb in the dripline soils of one residence had reduced RBAs by ~60%.

However, soils throughout the re mainder of the yard showed e ither no reduction in RBA or a

slight increase. A more complex study was conducted by Brown et al. (2003a) on an urban

dripline soil in the lab. The study used an asso rtment of locally derived biosolids (raw, ashed,

high-Fe compost, and compost) with and without lime. All amendments were incubated with

approximately 10% biosolids for a little more th an 30 days. In vitro and in vivo data both

indicated a 3 to 54% reduction in Pb RBA, w ith the high-Fe compost providing the greatest

reduction.

As with phosphate amendments, problems with biosolid application have also been

documented. Studies have shown that metal tran sport is significantly accelerated in soils

amended with biosolids (Al-Wabel et al., 2002 ; McBride et al., 1997, 19 99; Lamy et al., 1993;

Richards et al., 1998, 2000). Some of these stud ies indicate that metal concentrations in soil

solutions up to 80 cm below the amended surface in creased by 3- to 20-fold in concentration up

# AX7-22 to 15 years after biosolid applic ation. The increase in metal tr ansport is likely the result of

elevated dissolved organic carbon (DOC) in th e amended soil. Anodic stripping voltammetry

has indicated that very low percentages (2 to 18 %) of the soluble metals are present as ionic or

inorganic complexes (McBride, 1999; Al-Wabel et al., 2002).



# AX7.1.2 Distribution of Atmos pherically Delivered Lead in
Terrestrial Ecosystems

The 1986 Lead AQCD (U.S. Environmental Pr otection Agency, 1986a) contains only a

few minor sections that detail the speciation, distri bution, and behavior of atmospherically

delivered Pb in terrestrial ecosystems. The docum ent concluded that the majority of Pb in the

atmosphere at that time was from gasoline consum ption: of the 34,881 tons of Pb emitted to the

atmosphere in 1984, 89% was from gasoline us e and minor amounts were from waste oil

combustion, iron and steel production, and smelting. Lead in the atmosphere today, however, is

not primarily from leaded-gasoline consump tion, but results largely from iron and steel

foundaries, boilers and process he aters, the combustion of fossil fuels in automobiles, trucks,

airplanes, and ships, and othe r industrial processes (Table 2-8, Polissar et al., 2001; Newhook

et al., 2003). The emission source can determine the species of Pb that are delivered to terrestrial

ecosystems. For example, Pb species emitted from automobile exhaust is dominated by

particulate Pb halides and double salts with ammonium halides (e.g., PbBrCl, PbBrCl 2 

# NH 4 

# Cl),

while Pb emitted from smelters is dominated by Pb-sulfur species (Hab ibi, 1973). The halides

from automobile exhaust break down rapidly in the atmosphere, possibly via reactions with

atmospheric acids (Biggins and Harrison, 1979) . Lead phases in the atmosphere, and

presumably the compounds delivered to the surf ace of the earth (i.e., to vegetation and soils),

are suspected to be in the form of PbSO 4 

# , PbS, and PbO (Olson and Skogerboe, 1975; Clevenger

et al., 1991; Utsunomiya et al., 2004).

There are conflicting reports of how atmospherically derived Pb specifically behaves in

surface soils. This disagreement may represent the natural variability of the biogeochemical

behavior of Pb in different terrest rial systems, the different Pb s ources, or it may be a function of

the different analytical methods employed. The importance of humic and fulvic acids (Zimdahl

and Skogerboe, 1977; Gamble et al., 1983) and h ydrous Mn- and Fe-oxides (Miller and McFee,

1983) for scavenging Pb in soils are discussed in some detail in the 1986 Lead AQCD. Nriagu

# AX7-23 (1974) used thermodynamics to argue that Pb-orthophosphates (e.g., pyrom orphite) represented

the most stable Pb phase in many soils and sedime nts. He further suggest ed that, because of the

extremely low solubility of Pb-phosphate mine rals, Pb deposition could potentially reduce

phosphorous availability. Olson and Skoger boe (1975) reported that solid-phase PbSO 4



# dominated gasoline-derived Pb speciation in surface soils from Colorado, Missouri, and Chicago,

while Santillan-Medrano and Juri nak (1975) suggested that Pb(OH) 2 

# , Pb(PO 4 

# ) 2 

# , and PbCO 3



# could regulate Pb speciation in soils. However, insoluble organic materi al can bind strongly to

Pb and prevent many inorganic phases from ev er forming in soils (Zimdahl and Skogerboe,

1977).

The vertical distribution and mobility of at mospheric Pb in soils was poorly documented

prior to 1986. Chapter 6 of the 1986 AQCD cited a few references sugges ting that atmospheric

Pb is retained in the upper 5 cm of soil (Reav es and Berrow, 1984). Te chniques using radiogenic

Pb isotopes had been developed to discern betw een gasoline-derived Pb and natural, geogenic

(native) Pb, but these techniques were mostly app lied to sediments (Shiraha ta et al., 1980) prior

to the 1986 Lead AQCD. Without using these tec hniques, accurate determinations of the depthdistribution and potential migra tion velocities for atmospherically delivered Pb in soils were

largely unavailable.

Several technological advances , combined with the expans ion of existing technologies

after 1986 resulted in the publica tion of a large body of literatu re detailing the speciation,

distribution, and geochemical behavi or of gasoline-derived Pb in the terrestrial environment.

Most notably, the development of selective chemical extraction (S CE) procedures as a rapid and

inexpensive means for partitioning Pb into differe nt soil and sediment phases (e.g., Pb-oxides,

Pb-humate, etc.) has been exploited by a numbe r of researchers (Tessi er et al., 1979; Johnson

and Petras, 1998; Ho and Evans, 2000; Scheckel et al., 2003). Also, since 1986, several workers

have exploited synchrotron-based XAS in order to probe the electron co ordination environment

of Pb in soils, organic matter, organisms, a nd sediments (Manceau et al., 1996; Xia et al., 1997;

Trivedi et al., 2003). X-ray absorp tion studies can be used for th e in-situ determ ination of the

valence state of Pb and can be used to quantify Pb speciation in a variety of untreated samples.

Biosensors, which are a relatively new technolog y coupling biological material, such as an

enzyme, with a transducer, offer a new, simple , and inexpensive means for quantifying available

Pb in ecosystems (Verma and Singh, 2005). Advan ces in voltammetric, diffusive gradients in

# AX7-24 thin films (DGT), and ICP techniques have also increased the abilities of researchers to quantify

Pb phases in solutions (Berbel et al., 2001; Scally et al., 2003). In addition to the development of

techniques for describing and quantifying Pb speci es in the soils and solutions, researchers have

used radiogenic Pb isotopes ( 206 

# Pb, 207 

# Pb, 208 

# Pb) to quantify the dist ribution, speciation, and

transport of anthropogenic Pb in soil profiles and in vegetation (Bindler et al., 1999; Erel et al.,

2001; Kaste et al., 2003; Kl aminder et al., 2005).

Over the past several decades, workers have also developed time-series data for Pb in

precipitation, vegetation, organic horizons, mineral soils, and surface waters. Since

atmospherically delivered Pb often comprises a si gnificant fraction of the “l abile” Pb (i.e., Pb not

associated with primary minerals), these data have been useful for developing transport and

residence time models of Pb in different terrestrial re servoirs (Friedland et al., 1992; Miller and

Friedland, 1994; Johnson et al., 1995a; Wang and Benoit, 1997). Overall, a significant amount

of research has been publishe d on the distribution, sp eciation, and behavior of anthropogenic Pb

in the terrestrial environment since 1986. However, certain specific details on the behavior of Pb

in the terrestrial environment and its potential effects on soil microorganism s remain elusive.

AX7.1.2.1 Speciation of Atmospherically-del ivered Lead in Terrestrial Ecosystems

Lead in the Solid Phases

Lead can enter terrestrial ecosystems through natural rock weatheri ng and by a variety of

anthropogenic pathways. These different source terms control the species of Pb that is

introduced into the terrestrial environment. While Pb is highly concentrated (percent level) in

certain hydrothermal sulfide deposits (e.g., PbS) that are disseminated throughout parts of the

upper crust, these occurrences are relatively rare. Therefore, th e occurrence of Pb as a minor

constituent of rocks (ppm level) , particularly granites, rhyolit es, and argillaceous sedimentary

rocks is the more pertinent source term for the va st majority of terrestrial ecosystems. During

the hydrolysis and oxidation of Pb-containing mine rals, divalent Pb is released to the soil

solution where it is rapidly fixed by organic matter and se condary mineral phases (KabataPendias and Pendias, 1992). The geochemical form of natural Pb in terrestrial ecosystems will

be strongly controlled by soil type (Emmanuel a nd Erel, 2002). In cont rast, anthropogenically

introduced Pb has a variety of different geochemi cal forms, depending on the specific source.

While Pb in soils from battery reclama tion areas can be in the form of PbSO 4 

# or PbSiO 3 

# , Pb in

# AX7-25 soils from shooting ranges and paint spills is commonly found as PbO and a variety of Pb

carbonates (Vantelon et al., 2005; La perche et al., 1996; Manceau et al., 1996). Atmospherically

delivered Pb resulting from fossil fuel combustion is typically introduced into terrestrial

ecosystems as Pb-sulfur compounds and Pb oxides (Olson and Skogerboe, 1975; Clevenger

et al., 1991; Utsunomiya et al., 2004). After deposition, Pb species are likely transformed.

Although the specific factors that control the speciation of anthr opogenic Pb speciation in soils

are not well understood, there are many studies that have parti tioned Pb into its different

geochemical phases. A thorough understanding of Pb speciation is critical in order to predict

potential mobility and bioavail ability (see Section AX7.1.1).

Selective chemical extractions have been em ployed extensively over the past 20 years for

quantifying amounts of a particular metal phase (e.g., PbS, Pb-humate, Pb-Fe/Mn-oxide) present

in soil or sediment rather than total metal concentration. Sometimes selective chemical

extractions are applied sequentially to a particular sample. For example, the exchangeable metal

fraction is removed from the soil usin g a weak acid or salt solution (e.g., BaCl 2 

# ), followed

immediately by an extraction ta rgeting organic matter (e.g., H 2 

# O 2 

# or NaOCl), further followed by

an extraction targeting sec ondary iron oxides (e.g., NH 2 

# OH·HCl), and finally, a strong reagent

cocktail (e.g., HNO 3 

# -HCl-HF) targets primary minerals. Te ssier et al. (1979) developed this

technique. More recently, this technique has been modified and developed specifically for

different metals and different t ypes of materials (Keon et al., 2001). Alternatively, batch-style

selective chemical extractions have been used on soils and sediments to avoid the problems

associated with nonselective reagents (Johnson and Petras, 1998). Selective extractions can be a

relatively rapid, simple, and inexpensive means for determining metal phases in soils and

sediments, and the generated data can be linked to potential mobility and bioavailability of the

metal (Tessier and Campbell, 1987). However, some problems persist with the selective

extraction technique. First, extrac tions are rarely specific to a single phase. For example, while

H 2 

# O 2 

# is often used to remove meta ls bound to organic matter in soils, others have demonstrated

that this reagent destroys clay minerals and su lfides (Ryan et al., 2002). Peroxide solutions may

also be inefficient in removing metals bound to humic acids, and in fact could potentially result

in the precipitation of metal-humate substances. In addition to the nonselectivity of reagents,

significant metal redistribution has been docum ented to occur during sequential chemical

extractions (Ho and Evans, 2000; Sulkowski and Hirner, 2006), and many reagents may not

# AX7-26 completely extract targeted phases. While chemi cal extractions provide some useful information

on metal phases in soil or sedime nt, the results should be treated as “operationally defined,” e.g.,

“H 2 

# O 2 

# -liberated Pb” rather than “organic Pb.”

Lead forms strong coordination complexes wi th oxygen on mineral surfaces and organic

matter functional groups (Abd-Elfattah and Wada , 1981), because of its high electronegativity

and hydrolysis constant. Therefor e, Pb is generally not readily exchangeable, i.e., the amount of

Pb removed from soils by dilute acid or salts is usually less that 10% (Karamanos et al., 1976;

Sposito et al., 1982; Miller and McFee, 1983; Johnson and Petras, 1998; Bacon and Hewitt,

2005). Lead is typically adsorb ed to organic and inorganic so il particles str ongly via innersphere adsorption (Xia et al., 1997; Bargar et al., 1997a,b, 1998). Kaste et al. (2005) found that a

single extract of 0.02 M HCl remove d 15% or less Pb in organic horizons from a montane forest

in New Hampshire. The fact that relatively concentrated ac ids, reducing agents, oxidizing

agents, or chelating agents are requ ired to liberate the majority of Pb from soils is used as one

line of evidence that Pb migration and uptake by pl ants in soils is expected to be low.

Lead that is “organically bound” in soils is typically quantified by extractions that

dissolve/disperse or destroy organic matter. The former approach often employs an alkaline

solution (NaOH), which deprotonates organic ma tter functional groups, or a phosphate solution,

which chelates structural cations. Extractions used to destroy organic matter often rely on H 2 

# O 2



# or NaOCl. Both organic and mineral horizons typi cally have significant Pb in this soil phase.

Miller and McFee (1983) used Na 4 

# P 2 

# O 7 

# to extract organically bound Pb from the upper 2.5 cm of

soils sampled from northwestern Indiana. They found that organically bound Pb accounted for

between 25 and 50% of the total Pb present in the sampled topsoils . Jersak et al. (1997), Johnson

and Petras (1998), and Kaste et al. (2005) selectively extracted Pb from spodosols from the

northeastern United States . Using acidified H 2 

# O 2 

# , Jersak et al. (1997) found that very little

(<10 %) of the Pb in mineral soils (E, B, C) sampled from New York and Vermont was organic.

Johnson and Petras (1998) used K 4 

# P 2 

# O 7 

# to quantify organically bound Pb in the Oa horizon and

in mineral soils from the Hubbard Brook Experimental Forest in New Hampshire. They reported

that 60% of the total Pb in the Oa horizon was organic and that between 8 and 17% of the total

Pb in the mineral soil was organic. However, in the E, Bh, and Bs1 horizons, organically bound

Pb dominated the total “labile” (non-mineral lattice) Pb. Kaste et al. (2005) used selective

chemical extractions on organic horizons from m ontane forests in Vermont and New Hampshire.

# AX7-27 They found that repeated extractions with Na 4 

# P 2 

# O 7 

# removed between 60 and 100% of the Pb

from their samples. Caution should be used when interpreting the results of pyrophosphate

extractions. Although they are of ten used to quantify organically bound metals, this reagent can

both disperse and dissolve Fe phases (Jeanroy and Guillet, 1981; Shuman, 1982). Acidified

H 2 

# O 2 

# has also been reported to destroy and rel ease elements associated with secondary soil

minerals (Papp et al., 1991; Ryan et al., 2002).

Aside from organic forms, Pb is often f ound to be associated with secondary oxide

minerals in soils. Pb can be partitioned w ith secondary oxides by a variety of mechanisms,

including (1) simple ion excha nge, (2) inner-sphere or outer -sphere adsorption, and (3) coprecipitation and/or occlusion (Bargar et al., 1997a,b, 1998, 1999). As discussed above, very

little Pb is removed from soil via dilute acid or salt solutions, so adsorption and co-precipitation

are likely the dominant Pb interactions with secondary mineral phases. Reagents used to

quantify this phase are often so lutions of EDTA, oxal ate, or hydroxylamine hydrochloride (HH).

Miller and McFee (1983) used an EDTA solu tion followed by an HH solution to quantify Pb

occluded by Fe and Mn minerals, respectively, in th eir surface-soil samples from Indiana. They

reported that approximately 30% of the total soil Pb was occluded in Fe minerals, and 5 to 15%

was occluded in Mn phases. In soils from the northeastern United States, Jersak et al. (1997)

used various strengths of HH solutions and concl uded that negligible Pb was associated with

Mn-oxides and that 1 to 30% of th e Pb was associated with Fe phase s in the mineral soils in their

study. Johnson and Petras (1998) reported that no Pb was remove d from the Oa horizon at the

Hubbard Brook Experimental Forest (HBEF) by oxalate, but that 5 to 15% of the total Pb in

mineral soils was removed by this extraction, presumably because it was bound to amorphous

oxide minerals. Kaste et al. (2005), however, reported that HH removed 30 to 40% of the Pb

from organic horizons in their study. They concluded that Fe phases were important in

scavenging Pb, even in soil horizons dominated by organic matter.

Synchrotron radiation (X-rays) allows researchers to probe the electron conf iguration of

metals in untreated soil and sediment samples. Th is type of analysis has been extremely valuable

for directly determining the coordi nation environment of Pb in a variety of soils and sediments.

Since different elements have di fferent electron binding energies (E b 

# ), X-rays can be focused in

an energy window specific to a metal of interest. In experiments involving XAS, X-ray energy is

increased until a rapid increase in the amount of absorption occurs; this absorption edge

# AX7-28 represents E b 

# . The precise energy required to dislodge a core electron from a metal (i.e., E b 

# ) will

be a function of the oxidation state and covalency of the metal. X-ray absorption studies that

focus on the location of the absorption edge are referred to as XANES (X-ray absorption near

edge structure). In the ener gy region immediately after the absorption edge, X-ray absorption

increases and decreases with a periodicity that represents the wave f unctions of the ejected

electrons and the constructive and destructive inte rference with the wave functions of the nearby

atoms. X-ray absorption studies used to inve stigate the periodicity of the absorption after E b 

# are

referred to as EXAFS (extended X-ray absorp tion fine structure). Since the electron

configuration of a Pb atom will be directly governed by its speciation (e.g., Pb bound to organics,

Pb adsorbed to oxide surfaces, PbS, etc.) X- ray absorption studies provide a powerful in-situ

technique for determining specia tion without some of the proble ms associated with chemical

extractions (Bargar et al., 1997a,b, 1998).

Manceau et al. (1996) used EXAFS to study so il contaminated by gasoline-derived Pb in

France and found that the Pb was divalent a nd complexed to salicylate and catechol-type

functional groups of humic substances. He conc luded that the alkyl-tetravalent Pb compounds

that were added to gasoline we re relatively unstable and will not dominate the speciation of Pb

fallout from the combustion of leaded gasoline. The binding mechanism of Pb to organics is

primarily inner-sphere adsorption (Xia et al., 1997). DeVolder et al. (2003) used EXAFS to

demonstrate that Pb phases were shifting to th e relatively insoluble PbS when contaminated

wetland soils were treated with su lfate. Strawn and Sparks (2000) gave evidence that added Pb

was adsorbed directly onto organic matter in an untreated silt loam, but in the absence of organic

matter (treated with sodium hypochl orite) the added Pb appeared to adsorb instead to some form

of SiO 2 

# . More recent XAS studies have demonstrated the importance of biom ineralization of Pb

in soils by bacteria and nematodes (Xia et al., 1997; Templeton et al., 2003a,b; Jackson et al.,

2005). Templeton et al. (2003a,b) demonstrated that biogenic pr ecipitation of pyromorphite was

the dominant source of Pb uptake by Burkholderia cepacia biofilms below pH 4.5. Above pH

4.5, adsorption complexes began to form in addition to Pb mineral precipitation.

In addition to XAS studies of Pb in environm ental samples, numerous experimental-based

XAS studies have documented in detail the coor dination environment of Pb adsorbed to Feoxides, Mn-oxides, Al-oxides, and clay mine rals (Manceau et al., 1996, 2000a,b, 2002; Bargar

et al., 1997a,b, 1998, 1999; Strawn and Sparks, 1999; Trivedi et al., 2003; Chen et al., 2006).

# AX7-29 Bargar et al. (1997a) showed that Pb can adsorb to FeO 6 

# octahedra on three different types of

sites: on corners, edges, or faces. Ostergre n et al. (2000a,b) showed that the presence of

dissolved carbonate and sulfate increased Pb adsorbtion on goethite. The relative fraction of

corner-sharing complexes can be greatly increased by the presence of these ligands, as bridging

complexes between the metal and the corners are formed (Ostergren et al., 2000a,b).

Furthermore, Elzinga and Sparks showed th at the mechanism of Pb sorption to SiO 2 

# surfaces is

pH-dependent. In acid environments (pH < 4) Pb adsorbs largely as an inner-sphere mononulear

complex, but as pH increases, Pb sorption incr easingly occurs via the formation of surfaceattached covalent polynuclear Pb species.

Recently, Jackson et al. (2005) used microfoc used synchrotron-based X-ray fluorescence

( Φ SXRF) to detail the distribution of Pb and Cu in the nematode Caenorhabditis elegans. They

found that, while Cu was evenly distri buted throughout the bodies of exposed C. elegans, Pb was

concentrated in the anterior pharynx region. Mi crofocused X-ray diffrac tion indicated that the

highly concentrated Pb region in the pharynx was actually comp rised of the crystalline Pb

mineral, pyromorphite. The authors concluded that C. elegans precipitated pyromorphite in the

pharynx as a defense mechanism to prevent spre ading the toxic metal to the rest of the

organism’s body. They further suggested that, becau se of the high turnover rate of nematodes,

biomineralization could play an important role in the speciation of Pb in certain soils.

Lead Solid-solution Partitioning

The concentration of Pb species dissolved in soil solution is probabl y controlled by some

combination of (a) Pb-mineral solubility equili bria, (b) adsorption reactions of dissolved Pb

phases on inorganic surfaces (e.g., crystalline or amorphous oxides of Al, Fe, Si, Mn, etc.; clay

minerals), and (c) adsorption reactions of dissolv ed Pb phases on soil organic matter. Dissolved

Pb phases in soil solution can be some combination of Pb 2+ 

# and its hydrolysis species, Pb bound

to dissolved organic matter, and Pb comp lexes with inorganic ligands such as Cl ! 

# and SO 4 2 !



# .
Alkaline soils typically ha ve solutions supersaturat ed with respect to PbCO 3, 

# Pb 3 

# (CO 3 

# ) 2 

# (OH) 2 

# ,
Pb(OH) 2 

# , Pb 3 

# (PO 4 

# ) 2 

# , Pb 5 

# (PO 4 

# ) 3 

# (OH), and Pb 4 

# O(PO 4 

# ) 2 

# (Badawy et al., 2002). Pb-phosphate

minerals in particular are very insoluble, and calculations ba sed on thermodynamic data predict

that these phases will control dissolved Pb in soil solution under a variety of conditions (Nriagu,

# AX7-30 1974; Ruby et al., 1994). However, certain chelat ing agents, such as dissolved organic matter,

can prevent the precipitation of Pb minerals (Lang and Kaupenjohann, 2003).

Using a combination of desorption experi ments and XAS, EXAFS, and XANES, Rouff

et al. (2006) found that aging of Pb-calcite suspensions resulted in changes in the solid-phase

distribution of Pb. Increased sorption time can reduce trace metal desorption by enhancing the

stability of surface complexes (Rouff et al ., 2005) or by mechanisms involving microporous

diffusion (Backes et al., 1995), re crystallization-induced incor poration into the solid phase

(Ainsworth et al., 1994), and formation and stab ilization of surface precipitates (Ford et al.,

1999). For adsorption of Pb to hydrous Fe oxides, goethite, and Pb-contaminated soils, aged

samples show Pb to be reversibly bound, suggest ing Pb adsorption primarily to the substrates’

surfaces (Rouff et al., 2006). However, for Pb ad sorption to calcite aging played a significant

role due to detection of multiple sorption mechan isms, even for short sorption times (Rouff et al.,

2006). pH also played a role in Pb sorption. Over long sorption periods (60 to 270 days), slow

continuous uptake of Pb occurred at pH 7.3 a nd 8.2. At pH 9.4, no further uptake occurred with

aging and very little desorption occurred. These results show th e importance of contact time and

pH on Pb solid-phase partitioning, particularly in geochemical systems in which calcite may be

the predominant mineralogical constituent.

Soil solution dissolved organic matter content and pH typically have very strong positive

and negative correlations, respec tively, with the concentration of dissolved Pb species (Sauvé

et al., 1998, 2000a, 2003; Weng et al., 2002; Badawy et al., 2002; Tipping et al., 2003). In the

case of adsorption phenomena, the partitioning of Pb 2+ 

# to the solid phase is also controlled by

total metal loading, i.e., high Pb loadings will re sult in a lower fraction be ing partitioned to the

solid phase. Sauvé et al. (1997, 1998) demonstr ated that only a fraction of the total Pb in

solution was actually Pb 2+ 

# in soils treated with leaf compost. The fraction of Pb 2+ 

# to total

dissolved Pb ranged from <1 to 60%, depending on pH and the availability of Pb-binding

ligands. Nolan et al. (2003) used Donnan dialysis to show that 2.9 to 48.8% of the dissolved Pb

was Pb 2+ 

# in pore waters of agricultural and contam inated soils from Australia and the United

States. In acidic soils, Al sp ecies can compete for sites on natu ral organic matter and inhibit Pb

binding to surfaces (Gustafsson et al., 2003).

Differential pulse anodic stripp ing voltammetry (DPASV) is a t echnique that is useful for

identifying relatively lo w concentrations of Pb 2+ 

# and has found many applications in adsorption

# AX7-31 and partitioning experiments. Th is technique has been particular ly useful for quantifying the K d 

# ,
or partitioning ratio of Pb in the solid-to-liquid phase (K d 

# = [total solid-phase metal in mg kg Γ 1 

# ] /

[dissolved metal in mg L ! 1 

# ]). While the exact K d 

# value is a function of pH, organic matter

content, substrate type, total metal burden, and c oncentrations of competing ligands, such studies

typically show that Pb has very strong solid-phase partitioning. Partitioning ratios determined by

DPASV generally range from 10 3 

# to 10 6 

# in soils in the typical pH range (Sauvé et al., 2000b).

Aualiitia and Pickering (1987) used thin film ASV to compare th e relative affinity of Pb for

different inorganic particulates. They reported that Mn(IV) oxides completely adsorbed the Pb,

regardless of pH in the range of 3 to 9, and had the highest affinity for Pb in their study. The

adsorption of Pb to pedogenic Fe-oxides, Al-hydroxi des, clay minerals, and Fe ores was reported

to be pH-dependent. Sauvé et al. (1998) used DPASV to study the effects of organic matter and

pH on Pb adsorption in an orchard soil. They demonstrated that Pb complexation to dissolved

organic matter (DOM) increased Pb solubility, and that 30 to 50% of the dissolved Pb was bound

to DOM at pH 3 to 4, while >80% of the dissolved Pb was bound to DOM at neutral pH. They

concluded that in most soils, Pb in solution would not be found as Pb 2+ 

# but as bound to DOM.

Sauvé et al. (2000a) compared the relative affinity of Pb 2+ 

# for synthetic ferrihydrite, leaf

compost, and secondary oxide minerals collected from soils. They reported that the inorganic

mineral phases were more efficient at lowering the amount of Pb 2+ 

# that was available in solution

than the leaf compost. Glover et al. (2002) used DPASV in studying th e effects of time and

organic acids on Pb adsorption to goethite. They found that Pb adsorption to geothite was very

rapid, and remained unchanged after a period of about 4 h. Lead desorption was found to be

much slower. The presence of salicylate appeared to increase the amount of Pb that desorbed

from goethite more so than oxalate.

AX7.1.2.2 Tracing the Fate of Atmospherically-delivered Lead in Terrestrial Ecosystems

Radiogenic Pb isotopes offer a powerful tool for separating anthropogenic Pb from natural

Pb derived from mineral weathering (Erel and Pa tterson, 1994; Erel et al ., 1997; Semlali et al.,

2001). This has been particularly useful for studying Pb in mineral soil, where geogenic Pb

often dominates. The three ra diogenic stable Pb isotopes ( 206 

# Pb, 207 

# Pb, and 208 

# Pb) have a

heterogeneous distribution in the earth’s crust pr imarily because of the differences in the halflives of their respective parents ( 238 

# U, T 1/2 

# = 4.7 × 10 9 

# year; 235 

# U, T 1/2 

# = 0.7 × 10 9 

# year; 232 

# Th,

# AX7-32 T 1/2 

# = 14 × 10 9 

# year). The result is that the ore bodies from which anthropogenic Pb are typically

derived are usually enriched in 207 

# Pb relative to 206 

# Pb and 208 

# Pb when compared with Pb found in

granitic rocks. Graney et al. (1995) analyzed a dated core from Lake Erie, and found that the

206 

# Pb/ 207 

# Pb value in sediment deposited in th e late 1700s was 1.224, but in 20th-century

sediment, the ratio ranged from 1.223 to 1.197. This shift in the Pb isotopic composition

represents the introduction of a significant amount of anthropogenic Pb into the environment.

Bindler et al. (1999) and Emmanue l and Erel (2002) analyzed the isotopic composition of Pb in

soil profiles in Sweden and the Czech Republic, respectively, and determined that mineral soils

immediately below the organic horizon had a mixt ure of both anthropogenic and geogenic Pb.

Anthropogenic Pb has been detected relatively deep in to the soil profile (>25 cm) in Europe,

presumably this represents very “old”( i.e., pre-1900) Pb (Steinnes and Friedland, 2005).

Erel and Patterson (1994) used radiogenic Pb isotopes to trace the movement of industrial

Pb from topsoils to groundwaters to streams in a remote mountainous region of Yosemite

National Park in California. They calculated th at total 20th-century indus trial Pb input to their

study site was approximately 0.4 g Pb m Γ 2 

# . Lead concentrations in or ganic material were highest

in the upper soil horizons, and d ecreased with depth. During snowmelt, Pb in the snowpack was

mixed with the anthropogenic and geogenic Pb alr eady in the topsoil, a nd spring melts contained

a mixture of anthropogenic and geogenic particul ate Pb. During base flows, however, 80% of

the Pb export from groundwater and streams was from natural granite weathering (Erel and

Patterson, 1994).

Uranium-238 series 210 

# Pb also provides a tool for traci ng atmospherically delivered Pb in

soils. After 222 

# Rn (T 1/2 

# = 3.8 days) is produced from the decay of 226 

# Ra (T 1/2 

# = 1600 years), some

fraction of the 222 

# Rn escapes from rocks and soils to the atmosphere. It then decays relatively

rapidly to 210 

# Pb (T 1/2 

# = 22.3 years), which has a troposphe ric residence time of a few weeks

(Koch et al., 1996). Fallout 210 

# Pb is deposited onto forests via wet and dry deposition, similar to

anthropogenic Pb deposition in forests, and is thus useful as a tracer for non-native Pb in soils.

Lead-210 is convenient to use for calculating the re sidence time of Pb in soil layers, because its

atmospheric and soil fluxes can be assumed to be in steady state at undisturbed sites (Dörr and

Münnich, 1989; Dörr, 1995; Kast e et al., 2003). Atmospheric 210 

# Pb ( 210 

# Pb

ex 

# hereafter, 210 

# Pb in

“excess” of that supported by 222 

# Rn in the soil) must be calcul ated by subtracting the amount of

# AX7-33 210 

# Pb formed in soils by the in-situ decay of 222 

# Rn from the total 210 

# Pb (Moore and Poet, 1976;

Nozaki et al., 1978).

Benninger et al. (1975) measured fallout 210 

# Pb in soils and stream water at Hubbard Brook

and at an undisturbed forest in Penns ylvania. They estimated atmospheric 210 

# Pb export in

streamwaters to be <0.02% of the standing 210 

# Pb crop in the organic horizons. They used a

simple steady-state model to calculate the reside nce time of Pb in the organic horizons to be

5,000 years. This overestimate of the Pb reside nce time in the organic horizons was likely a

result of the low resolution of their sampling. Since they only sampled the upper 6 cm of soil

and the drainage waters, they did not accurately evaluate the distribution of 210 

# Pb in the soil

column in between. Dörr and Münnich (1989, 1991) used 210 

# Pb profiles in soils of southern

Germany to evaluate the behavior of atmospherically delivered P b. They calculated the vertical

velocity of Pb by dividing the rela xation depth (i.e., th e depth at which 210 

# Pb activity decreases to

1/ e , or approximately 37% of its surface value) by the 210 

# Pb mean life of 32 years. They reported

downward transit velocities of atmospheri cally deposited Pb at 0.89 ± 0.33 mm year Γ 1 

# . The

downward transport of atmospheric Pb was not aff ected by pH or soil type. However, since Pb

velocities in the soil profile where identic al to carbon velocities calculated with 14 

# C, they

concluded that Pb movement in forest soils is probably controlled by carbon transport. Kaste

et al. (2003) used 210 

# Pb to model the response time of atmo spherically delive red Pb in the O

horizon at Camel’s Hump Mountain in Vermont. They concluded th at the forest floor response

time was between 60 and 150 years, depending on vegetation zone and elevation. Using

206 

# Pb: 207 

# Pb, they also demonstrated that some gaso line-derived Pb migrated out of the O horizon

and into the mineral soil in th e deciduous vegetation zone on the mountain, while all of the

atmospheric Pb was retained in the upper 20 cm of the soil profile. Klaminder et al. (2006) used

210 

# Pb distributions to calculate the residence time of Pb in soils of Northern Sweeden. They

concluded that atmospheric Pb ha d a residence time of ~200 year s in the mor layer of mature

forests. They also provided evidence suggestin g that forests in an ea rlier stage of ecological

succession have a much shorter Pb reside nce time in the mor horizon (<50 years).

Researchers assessing the fate of atmospheric Pb in soils have also relied on repeated

sampling of soils and vegetation for total Pb (e.g., Zhang, 2003). This technique works best

when anthropogenic Pb accounts for the vast majority of total Pb in a particular reservoir.

Johnson et al. (1995a), Yanai et al. (2004), and Friedland et al. (1992) used O horizon (forest

# AX7-34 floor) time-series data to evaluate the movement of gasoline-derived Pb in the soil profile. These

studies have concluded that the distribution of Pb in the upper soil horizons has changed over the

past few decades. Yanai et al . (2004) documented a decline in Pb from the Oie horizon between

the late 1970s to the early 1990s in remote forest soils in New Hampshire. Johnson et al. (1995a)

and Friedland et al. (1992) dem onstrated that some fraction of Pb had moved from the O horizon

to the mineral soil during the 1980s at Hubbard Brook and at selected remote sites in the

northeastern United States, respectively. Evans et al. (2005) demonstrated th at Pb concentrations

in the litter layer (fresh litte r + Oi horizon) sampled in a transect from Vermont to Quebec

decreased significantly between 1979 and 1996, reflec ting a decrease in Pb deposition to forests

and upper soil horizons during that time period. Miller et al. (1993) and Wang and Benoit

(1997) used forest floor time-series data to model the response time ( e folding time, the time it

takes a reservoir to decrease to the 1/ e , (ca. 37%) of its original amount ) of Pb in the forest floor.

Miller et al. (1993) calculated O horizon response times of 17 years for the northern hardwood

forest and 77 years in the spruce-fir zone on Camel’s Hump Mountain in Vermont. Wang and

Benoit (1997) determined that the O horizon wo uld reach steady state with respect to Pb

(1.3 μg g Γ 1 

# Pb) by 2100. Both suggested that the vert ical movement of organic particles

dominated Pb transport in the soil profile.

AX7.1.2.3 Inputs/Outputs of Atmospherically-d elivered Lead in Terrestrial Ecosystems

The concentration of Pb in contemporary rain fall in the mid-Atlantic and northeastern

United States is on the order of 0.5 to 1 μg/L (Wang et al., 1995; Kim et al., 2000; Scudlark

et al., 2005). Long-term trends in nine elementa l concentrations (includi ng Pb) in wet deposition

were measured on the Delmarva Peninsula near Lewes, Delaware, over the period from 1982 to

1989 (Figure AX7-1.2.1) (Scudlark et al., 1994). Of the nine elements measured, only Pb (and

possibly Al and Cd), indicated a decreasing trend over time (3 μg/L in 1982 to <1.0 μg/L in

1989). The authors attributed the dramatic decr ease in Pb to the phasing out of Pb-alkyl

additives from gasoline as mandated in the 1972 Clean Air Act. For comparison, rainfall

measured in Los Angeles (CA) during 2003-2004 averaged 0.15 μg/L, but showed nearly an

order-of-magnitude variation, presumably because of the arid environmental (Sabin et al., 2005).

See also Table 2-22 for additional rainfall information.

# AX7-35 Figure AX7-1.2.1. Long-term (1982-1989) annual trends in lead concentrations (μg/L) in
Lewes, Delaware precipitation.

Source: Scudlark et al. (1994)



# The role of dry deposition in the total deposition of Pb to terrestrial ecosystems is not

constrained well. Researchers have estimat ed that dry deposition accounts for anywhere

between 10 to >90% of total Pb deposition (Galloway et al., 1982; Wu et al., 1994; Sabin et al.,

2005). Migon et al. (1997) found total, we t, and dry Pb deposition to be 8.6, 1.6 and

7.0 μg/m2/d, respectively, over the Ligurian Sea, France. Dry deposition velocities were

estimated at approximately 0.2 cm/sec, similar to anthropogenic element deposition velocities

measured at remote lakes around Lake Michigan (Yi et al., 2001). Yi et al. (2001) found that dry

deposition velocities for elements were correlated with particle concentrations in the following

order: coarse > total particle > fine particle. Refer to Table 2-21 for additional information on

dry, wet, and total Pb deposition velocities and fluxes.

Arid environments appear to have a much higher fraction of dr y deposition: total

deposition (Sabin et al., 2005). Furthermore, it is possible that Clean Air Act Legislation enacted

in the late 1970s preferentially reduced Pb associated with fine particles, so the relative

# AX7-36 contributions of dry deposition may have changed in the last few decades. If the major source of

Pb to a terrestrial ecosystem is resuspended part iculates from transportation corridors, then the

particle size fraction that domi nates deposition may be relatively coarse (>50 μm) relative to

other atmospheric sources (Pirrone et al., 1995; Sansal one et al., 2003).

Total contemporary loadings to terrestrial ecosystems are approximately 1 to 2 mg m Γ 2



# year Γ 1 

# (Wu et al., 1994; Wang et al., 1995; Simonetti et al., 2000; Sabi n et al., 2005). This is a

relatively small annual flux of Pb if compared to the reservoir of approximately 0.5 to 4 g m Γ 2 

# of

gasoline-derived Pb that is already in surface soils over much of the United States (Friedland

et al., 1992; Miller and Friedland, 1994; Erel and Patterson, 1994; Marsh and Siccama, 1997;

Yanai et al., 2004; Johnson et al., 2004; Evans et al., 2005). While vegetation can play an

important role in sequestering Pb from rain and dry deposition (Russell et al., 1981), direct

uptake of Pb from soils by plants appears to be low (Klaminder et al ., 2005). High elevation

areas, particularly those near th e base level of clouds often have higher burdens of atmospheric

contaminants (Siccama, 1974). A Pb deposition m odel by Miller and Friedland (1994) predicted

2.2 and 3.5 g Pb m Γ 2 

# deposition for the 20th century in the deciduous zone (600 m) and the

coniferous zone (1000 m), respec tively. More recently, Kaste etal. (2003) used radiogenic

isotope measurements on the same mountain to c onfirm higher loadings at higher elevation.

They measured 1.3 and 3.4 g gasoline-derived Pb m Γ 2 

# in the deciduous zone and coniferous

zones, respectively. Higher atmospheric Pb load ings to higher elevatio ns are attributed to

(1) the higher leaf area of coniferous species, which are generally more prevalent at high

elevation; (2) higher rain fall at higher elevation; and (3) in creased cloudwater impaction at high

elevation (Miller et al., 1993).

Although inputs of Pb to ecosystems are curren tly low, Pb export from watersheds via

groundwater and streams is substantially lower than inputs. Therefore, even at current input

levels, watersheds are accumulating industrial Pb . However, burial/movement of lead over time

down into lower soil/sediment layers also tends to sequester it away fr om more biologically

active parts of the watershed (unless later di sturbed or redistribute d, e.g., by flooding, dredging,

etc.). Seeps and streams at the HBEF have Pb concentrations on the order of 10 to 30 pg Pb g Γ 1



# (Wang et al., 1995). At a remote valley in the Si erra Nevada, Pb concentrations in streamwaters

were on the order of 15 pg Pb g Γ 1 

# (Erel and Patterson, 1994). Losses of Pb from soil horizons are

assumed to be via particulates (Dörr and Münnich, 1989; Wang and Benoit, 1996, 1997). Tyler

# AX7-37 (1981) noted that Pb losses from a spruce fore st A-horizon soil in Sweden were influenced by

season; with highest Pb fluxes being observed during warm, wet months. He suggested that

DOC production and Pb moveme nt were tightly linked.

Surface soils across the United States are enriched in Pb relative to levels expected from

solely natural geogenic inputs (Friedland et al., 1984; Herrick and Friedland, 1990; Francek,

1992; Erel and Patterson, 1994; Ma rsh and Siccama, 1997; Yanai et al., 2004; Murray et al.,

2004). While some of this contaminant Pb is attr ibuted to paint, salvage yards, shooting ranges,

and the use of Pb arsenate as a pesticide in localized areas (Fra ncek, 1997), Pb contamination of

surface soils is essentially ubiquitous because of atmospheric pollution associated with metal

smelting and production, the combustion of fossil fuels, and waste incine ration (Newhook et al.,

2003; Polissar et al., 2001). Surface soils in Mich igan, for example, typically range from 8 to

several hundred ppm Pb (Francek, 1992; Murray et al ., 2004). Soils collected and analyzed

beneath 50 cm in Michigan, however, range only from 4 to 60 ppm Pb (Murray et al., 2004).

In remote surface soils from the Sierra Nevada Mountains, litter and uppe r soil horizons are 20 to

40 ppm Pb, and approximately 75% of this Pb ha s been attributed to atmospheric deposition

during the 20th century (Erel and Patterson, 1994 ). Repeated sampling of the forest floor

(O horizon) in the northeastern United States demonstrates that the organic layer has retained

much of the Pb load deposited on ecosytems dur ing the 20th century. Total Pb deposition during

the 20th century has been estimated at 1 to 3 g Pb m Γ 2 

# , depending on elevation and proximity to

urban areas (Miller and Friedland, 1994; Johnson et al., 1995a). Forest floors sampled during the

1980s and 1990s, and in early 2000 had between 0.7 and 2 g Pb m Γ 2 

# (Friedland et al., 1992;

Miller and Friedland, 1994; Johns on et al., 1995a; Kaste et al., 2003; Yanai et al., 2004; Evans

et al., 2005). The pool of Pb in above- and belo w-ground biomass at the HBEF is on the order of

0.13 g Pb m Γ 2 

# (Johnson et al., 1995a).

The amount of Pb that has leached into mine ral soil appears to be on the order of 20 to

50% of the total anthropogenic Pb deposition. Kaste et al. (2003) and Miller and Friedland

(1994) demonstrated that Pb loss from the forest floor at Camel’s Hump Mountain in Vermont

depended on elevation. While the mineral soil in the deciduous forest had between 0.4 and 0.5 g

Pb m Γ 2 

# (out of 1 to 2 g Pb m Γ 2 

# in the total soil profile), at high er elevations the thicker coniferous

forest floor retained more than 90% of the tota l Pb deposition (Kaste et al., 2003). Johnson et al.

(1995a) determined that the forest floor at HBEF in the mid-1980s had about 0.75 g Pb m Γ 2



# .

# AX7-38 Compared to their estimated 20th-century atmospheric Pb deposition of 0.9 g Pb m Γ 2 

# , the forest

floor has retained 83% of the atmospheric Pb loadings (Johnson et al., 1995a). Johnson et al.

(2004) noted that gasoline-derived Pb was a signif icant component of the labile Pb at the HBEF.

They calculated that Pb fluxes to the HBEF by at mospheric pollution were essentially equivalent

to the Pb released by mineral weathering over the past 12,000 years. Marsh and Siccama (1997)

used the relatively homogenous mineral soils und erneath formerly plowed land in Rhode Island,

New Hampshire and Connecticut to assess the de pth-distribution of at mospheric Pb. They

reported that 65% of the atmospheric Pb deposite d during the 20th century is in the mineral soil

and 35% is in the forest floor. At their remote study site in the Sierra Nevada Mountains, Erel

and Patterson (1994) reported that most of the anthropogenic Pb was associated with the humus

fraction of the litter layer and soils sampled in the upper few cm.

Atmospherically delivered Pb is probably pres ent in ecosystems in a variety of different

biogeochemical phases. A combination of Pb ad sorbtion processes and th e precipitation of Pb

minerals will typically keep dissolved Pb sp ecies low in soil solution, surface waters, and

streams (Sauvé et al., 2000a; Jackson et al., 2005) . While experimental and theoretical evidence

suggest that the precipitation of inorganic Pb phases and the adsorption of Pb on inorganic

phases can control the biogeochemistry of c ontaminant Pb (Nriagu, 1974; Ruby et al., 1994;

Jackson et al., 2005), the influence of organic matt er on the biogeochemistry of Pb in terrestrial

ecosystems cannot be ignored in many systems. Organic matter can bind to Pb, preventing Pb

migration and the precipitation of inorganic phas es (Manceau et al., 1996 ; Xia et al., 1997; Lang

and Kaupenjohann, 2003). As the abundance of organic matter declines in so il, Pb adsorption to

inorganic soil minerals and the direct pr ecipitation of Pb phase s may dominate the

biogeochemistry of Pb in terrestrial ecosystems (Ostergren et al., 2000a,b ; Sauvé et al., 2000a).

Conclusions

Advances in technology since the 1986 Lead AQCD have allowed for a quantitative

determination of the mobility, di stribution, uptake, and fluxes of at mospherically delivered Pb in

ecosystems. Among other things, these studies have shown that industrial Pb represents a

significant fraction of total labile Pb in wate rsheds. Selective chemical extractions and

synchrotron-based X-ray studies have shown that industrial Pb can be strongly sequestered by

organic matter and by secondary minerals such as clays and oxides of Al, Fe, and Mn. Some of

# AX7-39 these studies have provided compelling evidence th at the biomineralizati on of Pb phosphates by

soil organisms can play an important role in th e biogeochemistry of Pb. Surface soils sampled

relatively recently demonstrate that the upper soil horizons (O + A horizons) are retaining most

of the industrial Pb burden introduced to the systems during the 20th century. The migration and

biological uptake of Pb in ecosystems is relativel y low. The different biogeochemical behaviors

of Pb reported by various studies may be a resu lt of the many different analytical techniques

employed, or they may be a result of natural vari ability in the behavior of Pb in different

systems.

Lead Uptake into Plants

Plants take up Pb via their foliage and th rough their root systems (U.S. Environmental

Protection Agency, 1986a; Påhlsson, 1989). Surface deposition of Pb onto plants may represent

a significant contribution to the total Pb in and on the plant, as has been observed for plants near

smelters and along roadsides (U.S. Environmen tal Protection Agency, 1986a). The importance

of atmospheric deposition on above-ground plant Pb uptake is well-documented (Dalenberg and

Van Driel, 1990; Jones and Johnston, 1991; Ange lova et al., 2004). Data examined from

experimental grassland plots in southeast England demonstrated th at atmospheric Pb is a greater

contributor than soil-derived Pb in crop plan ts and grasses (Jones and Johnston, 1991). A study

by Dalenberg and Van Driel (1990) showed that 75 to 95% of the Pb found in field-grown test

plants (i.e., the leafy material of grass, spinach, and carrot; wheat grain; and straw) was from

atmospheric deposition. Angelova et al. (2004) found that tobacco grown in an industrial area

accumulated significant amounts of Pb from the at mosphere, although uptake from soil was also

observed. The concentration of Pb in tobacco seeds was linearly related to the concentration of

Pb in the exchangeable and carbonate-bound fracti ons of soil, as measured using sequential

extraction (Angelova et al ., 2004). Lead in soil is more signi ficant when considering uptake into

root vegetables (e.g., carrot, potato), since, as was noted in th e 1986 Lead AQCD (U.S.

Environmental Protection Agency, 1986a), most Pb remains in the roots of plants.

There are two possible mechanisms (symplastic or apoplastic) by which Pb may enter the

root of a plant. The symplastic route is thr ough the cell membranes of ro ot hairs; this is the

mechanism of uptake for water and nutrients. Th e apoplastic route is an extracellular route

between epidermal cells into the intercellular sp aces of the root cortex. Previously, Pb was

# AX7-40 thought to enter the plant via the symplastic route, probably by tr ansport mechanisms similar to

those involved in the uptake of calcium or other divalent cations (i.e., transpirational mass flow,

diffusion, or active transport). However, it also had been speculated that Pb may enter the plant

via the apoplastic route (U.S . Environmental Protection Agency, 1986a). Sieghardt (1990)

determined that the mechanism of Pb uptake wa s via the symplastic route only and that the

apoplastic pathway of transport was stopped in the primary roots by the endodermis. He studied

the uptake of Pb into two plants, Minuartia verna (moss sandwort) and Silene vulgaris (bladder

campion) that colonize metal-contaminated sites. In the roots of both plants, Pb was found

mainly in the root cortex. Active ion uptake was required to transport the Pb into the stele and

then into the shoots of th e plant (Sieghardt, 1990).

Although some plants translocate more Pb to the shoots than others, most Pb remains in

the roots of plants. Two mechanisms have been proposed to account for this relative lack of

translocation to the shoots: (1) Pb may be deposited within root cell wall material, or (2) Pb may

be sequestered within root cell organelles (U.S. Environmental Protection Agency, 1986a).

Påhlsson (1989) noted that plants can accumulate large quantities of Pb from the soil but that

translocation to shoots and leaves is limited by th e binding of Pb ions at root surfaces and cell

walls. In a study by Wierzbicka (1999), 21 di fferent plant species were exposed to Pb 2+ 

# in the

form of Pb-chloride. The pl ant species included cucumber ( Cucumis sativus ), soy bean ( Soja

hispida ), bean ( Phaseolus vulgaris ), rapeseed ( Brassica napus ), rye ( Secale cereale ), barley

( Hordeum vulgare ), wheat ( Triticum vulgare ), radish ( Raphanus sativus ), pea ( Pisum sativum ),

maize ( Zea mays ), onion ( Allium cepa ), lupine ( Lupinus luteus ), bladder campion ( Silene

vulgaris ), Buckler mustard ( Biscutella laevigata ), and rough hawkbit ( Leontodon hispidus ).

Although, the amount of Pb taken up by the plant varied with species , over 90% of absorbed Pb

was retained in the root s. Only a small amount of Pb was tr anslocated (~2 to 4%) to the shoots

of the plants. Lead in roots was present in the deeper layers of r oot tissues (in particular, the root

cortex) and not only on the root surface. Th ere was no correlation between Pb tolerance

(measured as root mass increase expressed as a per centage of controls) and either root or shoot

tissue concentrations (Wierzbicka, 1999). The study by Wierzbicka (1999) was the first to report

that plants developing from bulbs, in this case the onion, were more tolerant to Pb than plants

developing from seeds. This tolerance was assume d to be related to the large amounts of Pb that

were transported from the roots and stored in the bulb of the plant (Wierzbicka, 1999).

# AX7-41 (AX7-1) Uptake of Pb from soil into plants was modeled as part of Eco-SSL development (U.S.

Environmental Protection Agency, 2005a). The re lationship derived between Pb in the soil and

Pb in a plant was taken from Bechtel Jac obs Company (BJC) (1998) and is as follows:

Ln(Cp) = 0.561 * Ln(Csoil)

− 1.328

where Cp is the concentration of Pb in the plant (dry weight) and Csoil is the concentration of Pb

in the soil. This equation r ecognizes that the rati o of Pb concentration in plant to Pb

concentration in soil is not constant.

Invertebrates

There was no clear evidence suggesting a differential uptake of Pb into different species

of earthworm ( Lumbricus terrestris

, Aporrectodea rosea , and A. caliginosa ) collected around a

smelter site near Avonmouth, Englan d (Spurgeon and Hopkin, 1996a). Th is is in contrast to Pižl

and Josens (1995) and Terhivuo et al. (1994) who found Aporrectodea spp. accumulated more

Pb than Lumbricus . The authors suggested that these differences c ould be due to different

feeding behaviors, as Lumbricus feeds on organic material and Apporectodea species are

geophagus, ingesting large amounts of soil during f eeding. The differences between species also

may be related to differing efficiencies in excretory mechanisms (Pižl and Josens, 1995).

However, the interpretation of species differe nce is complicated by a number of potentially

confounding variables, such as soil characteri stics (e.g., calcium or other nutrient levels)

(Pižl and Josens, 1995).

The bioaccumulation of Pb from contaminat ed soil was tested using the earthworm

Eisenia fetida , and the amount of Pb accumulated did not change significantly until the

concentration within soil reached 5000 mg/kg (D avies et al., 2003). This coincided with the

lowest soil concentrations at which earthw orm mortality was observed. The ratio of the

concentration of Pb in worms to the concentr ation in soil decreased from 0.03 at 100 mg/kg to

0.001 at 3000 mg/kg, but then increased quickly to 0.02 at 5000 mg/kg. The authors concluded

that earthworms exhibit regulated uptake of Pb at levels of low cont amination (<3000 mg/kg)

until a critical concentration is reached, at whic h point this mechanism breaks down, resulting in

unregulated accumulation and mortality. This study was conducted using test methods where

# AX7-42 (AX7-2) soil was not allowed to equilibrate following the a ddition of Pb and prior to the addition of the

test organisms. This may have resulted in an increased bioavailability and overestimated Pb

toxicity relative to actual environmental condit ions (Davies et al., 2003). See the discussion in

Section AX7.1.2 on the effects of aging on Pb sorption processes.

Lock and Janssen (2002) and Bongers et al. (2004) found that Pb-nit rate was more toxic

than Pb-chloride to survival and reproduction of the springtail Folsomia candida . However,

percolation (removal of the chlori de or nitrate counterion) caused a significant decrease in Pbnitrate toxicity such that there was no differe nce in toxicity once th e counterion was removed

(Bongers et al., 2004). No change in toxicity was observed for Pb-chloride once the chloride

was removed from the soil. Bongers et al. (2004) suggested that the nitr ate ion was more toxic

than the chloride ion to springtails.

Uptake of Pb from soil into earthworms was also modeled as part of Eco-SSL

development (U.S. Environmental Protection Agen cy, 2005a). The relationship derived between

Pb in the soil and Pb in an earthworm was take n from Sample et al. ( 1999) and is as follows:

Ln(Cworm) = 0.807 * Ln(Csoil) – 0.218

where Cworm is the concentration of Pb in the earthworm (dry wei ght) and Csoil is the

concentration of Pb in the soil. This equation recognizes that th e ratio of Pb concentration in

worm to Pb concentration in soil is not constant.

Wildlife

Research has been conducted to determine wh at Pb concentrations in various organs

would be indicative of various le vels of effects. For example, Franson (1996) compiled data to

determine what residue levels were consistent with three levels of effects in Falconiformes (e.g.,

falcons, hawks, eagles, kestrels, ospreys), Co lumbiformes (e.g., doves, pigeons), and Galliformes

(e.g., turkey, pheasant, partridge, quail, chickens). The three levels of eff ect were (1) subclinical,

which are physiological effects only, such as the inhibition of δ -aminolevulinic acid dehydratase

(ALAD; see Section AX7.1.3.3); (2) t oxic, a threshold level marki ng the initiation of clinical

signs, such as anemia, lesions in tissues, weight loss, muscular incoor dination, green diarrhea,

and anorexia; and (3) compatible with death, an approximate threshold value associated with

# AX7-43 death in field, captive, and/or experimental cases of Pb poisoning. The tissue Pb levels

associated with these levels of effects are presented in Table AX7-1.2.1.

Table AX7-1.2.1. Tissue Lead Levels in Birds Causing Effects
(taken from Franson, 1996)

Order 

# Blood (μg/dL) Liver (ppm wet wt.) Kidney (ppm wet wt.)

Falconiformes

Subclinical 0.2 – 1.5 2 – 4 2 – 5

Toxic >1 >3 >3

Compatible with death >5 >5 >5

Columbiformes

Subclinical 0.2 – 2.5 2 – 6 2 – 20

Toxic >2 >6 >15

Compatible with death >10 >20 >40

Galliformes

Subclinical 0.2 – 3 2 – 6 2 – 20

Toxic >5 >6 >15

Compatible with death >10 >15 >50



# Tissue residue levels below the subclini cal levels in Table AX7-1.2.1 should be

considered “background” (Franson, 1996). Levels in the subclinical rang e are indicative of

potential injury from which th e bird would probably recover if Pb exposure was terminated.

Toxic residues could lead to death. Residues above the compa tible-with-death threshold are

consistent with Pb-poisoning mortality (Fra nson, 1996). Additional information on residue

levels for Passeriformes (e.g., sparrows, starlings , robins, cowbirds), Charadriiformes (e.g., gulls,

terns), Gruiformes (e.g., cranes), Ciconiformes (e.g., egrets), Gaviformes (e.g., loons), and

Strigiformes (e.g., owls) is available in Fr anson (1996). Scheuhammer (1989) found blood Pb

concentrations of between 0.18 and 0.65 μg/m L in mallards corresponded to conditions

associated with greater than normal exposure to Pb but that should not be considered Pb

poisoning.

# AX7-44 (AX7-3) Lead concentrations in various tissues of mammals also have b een correlated with toxicity

(Ma, 1996). The tissues commonly analysed fo r Pb are blood, liver, and kidney. Typical

baseline levels of blood Pb are approximately 4 to 8 μg/dL for small mammals, and 2 to 6 μg/dL

for mature cattle. Typical baseline levels of Pb in liver are 1 to 2 mg/kg dw for small mammals.

Typical baseline levels of Pb in kidney are 0.2 to 1.5 mg/kg dw for mice and voles, but shrews

typically have higher baseline leve ls of 3 to 19 mg/kg dw. Ma ( 1996) concluded that Pb levels

less than 5 mg/kg dw in liver a nd 10 mg/kg dw in kidney were not associated with toxicity, but

that levels greater than 5 mg/kg dw in liver a nd greater than 15 mg/kg dw in kidney could be

taken as a chemical biomarker of toxic exposur e to Pb in mammals. Humphreys (1991) noted

that the concentrations of Pb in liver and kidne y can be elevated in animals with normal blood Pb

concentrations (and without exhibiting clinical signs of Pb toxicity), because Pb persists in these

organs longer than in blood.

Uptake of Pb from soil into small mammals was also modeled as part of Eco-SSL

development (U.S. Environmental Protection Agen cy, 2005a). The relationship derived between

Pb in the soil and Pb in the whole-body of a small mammal was taken from Sample et al. (1998)

and is as follows:

Ln(Cmammal) = 0.4422 * Ln(Csoil) + 0.0761

Where Cmammal is the concentration of Pb in small mammals (dry weight) and Csoil is the

concentration of Pb in the soil. Similar to the uptake equations fo r plants (Eq. 8-1) and

earthworms (Eq 8-2), the equation for mammalia n uptake recognizes that the ratio of Pb

concentration in small mammals to Pb concentration in soil is not constant.

AX7.1.2.4 Resistance Mechanisms

Many mechanisms related to heavy metal tolera nce in plants and invertebrates have been

described, including avoidance (i.e., root redistribution, food rejecti on), exclusion (i.e., selective

uptake and translocation), immobilization at th e plant cell wall, and excretion (i.e., foliar

leakage, moulting) (Tyler et al., 1989; Patra et al., 2004). The following section reviews the

recent literature on the resistance mechanisms of plants and invertebrates through mitigation of

Pb (1) toxicity or (2) exposure.

# AX7-45 Detoxification Mechanisms

Lead sequestration in cell walls may be the most important detoxification mechanism in

plants. Calcium may play a role in this detoxi fication by regulating intern al Pb concentrations

through the formation of Pb-cont aining precipitates in the cell wall (Antosiewicz, 2005). Yang

et al. (2000) screened 229 varieties of rice ( Oryza sativa ) for tolerance or sensitivity to Pb and

found that the oxalate conten t in the root and root exudates was in creased in Pb-tolerant varieties.

The authors suggested that the ox alate reduced Pb bioavailability, and that this was an important

tolerance mechanism (Yang et al., 2000). Sharma et al. (2004) found Pb-sul fur and Pb-sulfate in

the leaves, and Pb-sulfur in the roots of Sesbania drummondii (Rattlebox Drummond), a Pb

hyperaccumulator plant grown in Pb-nitrate solu tion. They hypothesized that these sulfur

ligands were indicative of glutathione and phytoc helatins, which play a role in heavy metal

homeostasis and detoxificati on (Sharma et al., 2004).

Sea pinks ( Armeria maritima ) grown on a metal-contaminated site (calamine spoils more

than 100 years old) accumulated 6 Η the concentrations of Pb in brown (dead and withering)

leaves than green leaves (Szarek -Lukaszewska et al., 2004). The concentration of Pb in brown

leaves was similar to that in roots. This grea ter accumulation of Pb in to older leaves was not

observed in plants grown hydroponically in the la boratory. The authors hypothesized that this

sequestering of Pb into the oldest leaves wa s a detoxification mechan ism (Szarek-Lukaszewska

et al., 2004).

Terrestrial invertebrates also mitigate Pb t oxicity. Wilczek et al. (2004) studied two

species of spider , the web-building Agelena labyrinthica, and the active hunter wolf spider

Pardosa lugubris . The activity of metal detoxifying en zymes (via the glutathione metabolism

pathways) was greater in A. labyrinthica and in females of both species (Wilczek et al., 2004).

Marinussen et al. (1997) found th at earthworms can excrete 60% of accumulated Pb very

quickly once exposure to Pb-contaminated soils has ended. However, the remainder of the body

burden is not excreted, possibly due to the storage of Pb in waste nodules that are too large to be

excreted (Hopkin, 1989). Gintenreit er et al. (1993) found that Le pidoptera larvae (in this case,

the gypsy moth Lymantria dispar ) eliminated Pb, to some extent, in the meconium (the fluid

excreted shortly after emergence from the chrysalis).

Lead, in the form of pyromorphite (Pb 5 

# (PO 4 

# ) 3 

# Cl), was localized in the anterior pharynx

region of the nematode Ceanorhabditis elegans (Jackson et al., 2005). The authors hypothesized

# AX7-46 that the nematode may detoxify Pb via its precipitation into pyromorphite, which is relatively

insoluble (Jackson et al., 2005).

Avoidance Response

Studies with soil invertebrates hypothesize th at these organisms ma y avoid soil with high

Pb concentrations. For example, Bengtsson et al. (1986) suggested that the lower Pb

concentrations in earthworm tissues may be a result of lowered feeding activity of worms at

higher Pb concentrations in soil.

AX7.1.2.5 Physiological Effects of Lead

Several studies have measured decrease d blood ALAD activity in birds and mammals

exposed to Pb (U.S. Environmental Protec tion Agency, 1986a). Recent studies on the

physiological effects of Pb to consumers have focused on heme synthesis (as measured by

ALAD activity and protoporphyrin concentration) , lipid peroxidation, an d production of fatty

acids. Effects on growth are covered in Section AX7.1.4.

Biochemically, Pb adversely affects hemoglobi n synthesis in birds and mammals. Early

indicators of Pb exposure in birds and mamm als include decreased blood ALAD concentrations

and increased protoporphyrin IX activity. The effects of Pb on blood parameters and the use of

these parameters as sensitive biomarkers of exposure has been well documented (Eisler, 1988;

U.S. Environmental Protection Agency, 2005b). However, the linkage between these

biochemical indicators and ecol ogically relevant effects is less well understood. Low-level

inhibition of ALAD is not generally considered a toxic response, because this enzyme is thought

to be present in excess concentrations; rather , it may simply indicate that the organism has

recently been exposed to Pb (Henny et al., 1991).

Schlick et al. (1983) studied ALAD inhibiti on in mouse bone marrow and erythrocytes.

They estimated that an absorbed dose of between 50 and 100 μg Pb-acetate/kg body weight per

day would result in long-term inhibition of ALAD.

Beyer et al. (2000) related blood Pb to s ublethal effects in waterfowl along the

Coeur d
= Alene River near a mining site in Idaho. The sublethal effects measured included,

among others, red blood cell ALAD activity and prot oporphyrin levels in th e blood. As found in

other studies, ALAD activity was th e most sensitive indicator of Pb exposure, decreasing to 3%

# AX7-47 of the reference value at a blood Pb con centration of 0.68 mg/kg ww (wet weight).

Protoporphyrin concentrations showed a 4.2-fold increase at this same concentration.

Henny et al. (1991) studied osprey along the Coeur d
= Alene River. There were no

observations of death, behavioral abnormalities, or reduced productivity re lated to Pb exposure,

although inhibition of blood ALAD and increased pr otoporphyrin concentrations were measured

in ospreys. Henny et al. (1991) hypothesized th at no impacts to osprey were observed, even

though swan mortality was documented in the area because swans feed at a lower trophic level

(i.e., Pb does not biomagnify, and thus is found at higher concentrations in lower trophic level

organisms).

Hoffman et al. (2000a) also studied the e ffects of Coeur d’Alene River sediment on

waterfowl, focusing on mallard ducklings for 6 w eeks after hatching. The study revealed that a

90% reduction in ALAD activity and a greate r than 3-fold increase in protoporphyrin

concentration occurred when blood Pb reached a concentration of 1.41 mg/kg ww as a result of

the ducklings being fed a diet composed of 12% sediment (3449 mg/kg Pb). Those ducklings

fed a diet composed of 24% sediment were found to have a mean blood Pb concentration of

2.56 mg/kg ww and a greater than 6-fold increase in protoporphyrin concentration. Hoffman

et al. (2000b) also studied Canada Geese ( Branta canadensis ) goslings in a similar fashion.

The results revealed that, while blood Pb concen trations in goslings we re approximately half

(0.68 mg/kg ww) of those found in ducklings under the same conditions (12% diet of

3449 mg/kg sediment Pb), goslings showed an increased sensitivity to Pb exposure. Goslings

experienced a 90% reduction in ALAD activit y and a 4-fold increase in protoporphyrin

concentration, similar to conditions found in th e ducklings, although blood Pb concentrations

were half those found in the duckl ings. More serious effects we re seen in the goslings when

blood Pb reached 2.52 mg/kg, including d ecreased growth an d mortality.

Redig et al. (1991) reported a hawk LOAEL (lowest observed adverse effect level) of

0.82 mg/kg-day for effects on heme biosynthetic pathways. Lead dosages as high as 1.64 to

6.55 mg/kg-day caused neither mortal ity nor clinical signs of toxicity. A dose of 6.55 mg/kg-day

resulted in blood Pb levels of 1.58 μg/mL. Th ere were minimal changes in immune function

(Redig et al., 1991).

Repeated oral administration of Pb resulted in biochemical alterations in broiler chickens

(Brar et al., 1997a,b). At a dose of 200 mg/kg-day Pb -acetate, there were significant increases in

# AX7-48 plasma levels of uric acid and cr eatinine and significant declines in the levels of total proteins,

albumin, glucose, and cholesterol. Brar et al. (1997a) suggested that increased uric acid and

creatinine levels could be due to an accelerated rate of protein catabolism and/or kidney damage.

They also suggested that the decline in plasma proteins and albumin levels may be caused by

diarrhea and liver dysfunction due to the Pb e xposure. Brar et al. (1997b) also found that

significant changes in plasma enzymes may be causing damage to other organs.

Lead can cause an increase in tissue lip id peroxides and changes in glutathione

concentrations, which may be related to peroxi dative damage of cell membranes (Mateo and

Hoffman, 2001). There are species-specific differen ces in resistance to oxidative stress (lipid

peroxidation), which may explain why Canada g eese are more sensitive to Pb poisoning than

mallards (Mateo and Hoffman, 2001). Lead also cau sed an increase in the production of the fatty

acid arachidonic acid, which has been associated with changes in bone formation and immune

response (Mateo et al., 2003a). The effects observed by Mateo et al. (2003a,b) were associated

with very high concentrations of Pb in the diet (1840 mg Pb/kg diet), much higher than would be

found generally in the environment, and high en ough that birds decreased their food intake.

Lead also induces lipid peroxi dation in plants. Rice plants exposed to a highly toxic level

of Pb (1000 μM in nutrient solution) showed elevat ed levels of lipid peroxides, increased activity

of superoxide dismutase, guaiacol peroxidase, ascorbate peroxidase, a nd glutatione reductase

(Verma and Dubey, 2003). The elevated levels of these enzymes suggest the plants may have an

antioxidative defense mechanism against oxida tive injury caused by Pb (Verma and Dubey,

2003).

AX7.1.2.6 Factors that Modify Organism Response

Research has demonstrated that Pb ma y affect survival, reproduction, growth,

metabolism, and development in a wide range of species. These effects may be modified by

chemical, biological, and physical factors. The f actors that modify respons es of organisms to Pb

are described in the following sections.

Genetics

Uptake and toxicity of Pb to plants are influenced strongly by the type of plant. Liu et al.

(2003) found that Pb uptake and translocation by rice plants differed by cultivar (a cultivated

# AX7-49 variety of plant produced by se lective breeding) but was not related to genotype. Twenty

cultivars were tested from three genotypes. The differences in Pb concentrations among

cultivars were smallest when comparing concentr ations in the grains at the ripening stage.

This study also found that toxicity varied by cu ltivar; at 800 mg Pb/kg soil, some cultivars

were greatly inhibited, some were significantly improved, and others showed no change.

Dearth et al. (2004) compared the response of Fisher 344 (F344) rats and Sprague-Dawley

(SD) rats to exposure via gavage to 12 mg Pb/mL as Pb-acetate. Blood Pb levels in the F344

dams were higher than those of the SD da ms. Lead delayed the timing of puberty and

suppressed hormone levels in F344 offspring. Th ese effects were not obs erved in the offspring

of SD rats, even when the dose was doubled. The authors conclude that F344 rats are more

sensitive to Pb (Dear th et al., 2004).

Biological Factors

Several biological factors may influence Pb uptake and organism response, including

organism age, sex, species, feeding guild, and, fo r plants, the presence of mycorrhizal fungi.

Monogastric animals are more sensitive to Pb than ruminants (Humphreys, 1991).

Younger organisms may be more susceptible to Pb toxicity (Eisler, 1988; Humphreys,

1991). Nestlings are more sensitive to the effects of Pb than older birds, and young altricial birds

(species unable to self-regulate body heat at birt h, such as songbirds) , are considered more

sensitive than precocial birds (species that have a high degree of independe nce at birth, such as

quail, ducks, and poultry) (Scheuhammer, 1991).

Gender can also have an effect on the accu mulation of Pb by wild life (Eisler, 1988).

Female birds accumulate more Pb than males (Scheuhammer, 1987; Tejedor and Gonzalez,

1992). These and other authors ha ve related this to the increas ed requirement for calcium in

laying females.

Different types of invertebrates accumulate different amounts of Pb from the environment

(U.S. Environmental Protection Agency, 1986a). There may be species- and sex-specific

differences in accumulation of Pb into invertebra tes, specifically arthropods. This has been

shown by Wilczek et al. (2004) who studied two species of spider, the web-building

A. labyrinthica and the active hunter wolf spider P. lugubris . The body burdens of Pb in the

wolf spider were higher than in the web-build ing spider, and this ma y be due to the more

# AX7-50 effective use of glutathione metabolism pathways in A. labyrinthica . Body burdens of females

were lower than those of males in both species. This was also observed in spiders by Rabitsch

(1995a). Females are thought to be able to deto xify and excrete excess metals more effectively

than males (Wilczek et al., 2004). Lead accumulation has been measured in numerous species of

arthropods with different feed ing strategies. Differences were observed between species

(Janssen and Hogervorst, 1993; Rabitsch, 1995a) and depending upon sex (Rabitsch, 1995a),

developmental stage (Gintenreiter et al., 1993; Rabitsch, 1995a), and season (Rabitsch, 1995a).

Uptake of Pb may be enhanced by symbio tic associations between plant roots and

mycorrhizal fungi. Similar to the mechanism a ssociated with increased uptake of nutrients,

mycorrhizal fungi also may cause an increase in the uptake of Pb by increasing the surface area

of the roots, the ability of the root to absorb pa rticular ions, and the tran sfer of ions through the

soil (U.S. Environmental Protection Agency, 1986a). There have been contradictory results

published in the literature rega rding the influence of mycorrhizal organisms on the uptake and

toxicity of Pb to plants (see review in Påhlsson, 1989). Lin et al . (2004) found that the

bioavailability of Pb increased in the rhizosphere of rice plants, although th e availability varied

with Pb concentration in soil. Bioavailability wa s measured as the soluble plus exchangeable Pb

fraction from sequential extrac tion analysis. The authors hyp othesized that the enhanced

solubility of Pb may be due to a reduced pH in the rhizosphere or, more likely, the greater

availability of organic ligands, which further s timulates microbial growth (Lin et al., 2004).

Increased bioavailability of Pb in soil may increase the uptak e of Pb into plants, although

this was not assessed by Lin et al. (2004). However, Di xon (1988) found that red oak

( Quercus rubra ) seedlings with abundant ectomycorrhizae had lower Pb concentrations in their

roots than those seedlings w ithout this fungus, although only at the 100 mg Pb/kg sandy loam

soil concentration (no differences were found at lowe r Pb concentrations). Lead in soil also was

found to be toxic to the ectomycorrhizal fungi after 16 weeks of exposure to 50 mg Pb/kg or

more (Dixon, 1988). Malcova and Gryndler (2003) showed that maize root exudates from

mycorrhizal fungi can ameliorate heavy metal toxi city until a threshold metal concentration was

surpassed. This may explain the conflicting results in the past regarding the uptake and toxicity

of Pb to plants with mycorrhizal fungi.

The type of food eaten is a major determinan t of Pb body burdens in small mammals, with

insectivorous animals accumulating more Pb than herbivores or granivores (U.S. Environmental

# AX7-51 Protection Agency, 1986a). In fact, the main i ssue identified by the EPA (U.S. Environmental

Protection Agency, 1986a) related to invertebra te uptake of Pb was not toxicity to the

invertebrates, but accumulation of Pb to levels th at may be toxic to their consumers. Several

authors suggest that shrews are a good indicato r of metal contamination, because they tend to

accumulate higher levels of metals than herb ivorous small mammals (see data summary in

Sample et al. (1998)). Shrews accumulate higher levels of metals in contaminated habitats,

because their diet mainly consists of detritivores (i.e., earthworms) and other soil invertebrates in

direct contact with the so il (Beyer et al., 1985).

Physical/Environmental Factors

Plants

The uptake and distribution of Pb into higher plants from the soil is affected by various

chemical and physical factors including the chemi cal form of Pb, the pr esence of other metal

ions, soil type, soil pH, cati on exchange capacity (CEC), the amount of Fe/Mn-oxide films

present, organic matter content, temperature, ligh t, and nutrient availability. A small fraction of

Pb in soil may be released into the soil water, which is then available to be taken up by plants

(U.S. Environmental Protection Agency, 1986a).

The form of Pb has an influen ce on its toxicity to plants. Fo r example, Pb-oxide is less

toxic than more bioavailable forms such as Pb -chloride or Pb-acetate. In a study by Khan and

Frankland (1983), radish plants were exposed to Pb-oxide and Pb-chloride in a loamy sand at pH

5.4, in a 42-day study. In a tested concentrati on range of 0 to 5000 mg/kg, root growth was

inhibited by 24% at 500 mg/kg for Pb-chloride and an EC 50 

# of 2400 mg/kg was calculated from a

dose-response curve. Plant growth ceased at 5000 mg/kg and shoots exhibited an EC 50 

# of

2800 mg/kg. For Pb-oxide exposure (concentration range of 0 to 10,000 mg/kg), reported results

indicate an EC 50 

# of 12,000 mg/kg for shoot growth and an EC 50 

# of 10,000 mg/kg for root growth.

There was no effect on root growth at 500 mg/ kg and a 26% reduction at 1000 mg/kg Pb oxide.

Soil pH is the most influential soil property wi th respect to uptake and accumulation of Pb

into plant species. This is most likely due to increased bioavailability of Pb created by low soil

pH. At low soil pH conditions, markedly elevat ed Pb toxicity was reported for red spruce

( P. rubens ) (Seiler and Paganelli, 1987). At a soil pH of 4.5, ryegrass ( Lolium hybridum )

# AX7-52 and oats ( Avena sativa ) had significantly higher Pb concentr ations after 3 months of growth

compared to plants grown at pH 6.4 (Allinson and Dzialo, 1981).

Invertebrates

The uptake of Pb into invert ebrates depends on the physical environment and parameters

such as pH, calcium concentration, organic matte r content, and CEC. Greater accumulation is

found generally when the soil pH or organic content is lower (U.S. Environmental Protection

Agency, 1986a).

Soil pH has a significant influence on uptake of Pb into invertebrates. Perämäki et al.

(1992) studied the influence of soil pH on uptake into the earthworm Aporrectodea caliginosa

. Lead accumulation was lowest at the highest pH values, but there was no statistical difference

due to variability in the data. Variability in the response also was found by Bengtsson et al.

(1986), who reared earthworms ( Dendrobaena rubida ) in acidified soils at pH 4.5, 5.5, or 6.5.

Lead uptake into worms was pH-dependent, although the highest concentrations were not always

found at the lowest pH. There was no clear re lationship between Pb concentration in cocoons

and soil pH, and Pb concentrations were higher in the hatchlings than in the cocoons. As has

been reported in many other studies (Neuhauser et al., 1995), concentration fa ctors (ratio of Pb in

worm to Pb in soil) were lower at higher Pb conc entrations in soil. The authors attribute some of

this to a lowered feeding activity in worms at hi gher Pb concentrations (Bengtsson et al., 1986).

Beyer et al. (1987) and Morgan and Morgan (1 988) recognized that other factors beyond

soil pH could influence the uptake of Pb into earthworms, which may be the cause of the

inconsistencies reported by several authors. Both studies ev aluated worm uptake of Pb relative

to pH, soil calcium concentration, and organic ma tter content. Morgan and Morgan (1988) also

considered CEC, and Beyer et al. (1987) consid ered concentrations of phosphorus, potassium, or

magnesium in soil. Both studies found that calc ium concentrations in soil were correlated with

soil pH. Morgan and Morgan (1988) also f ound that CEC was correlated with percentage

organic matter. Soil pH (coupled with CEC) a nd soil calcium were found to play significant

roles in the uptake of Pb into worms (Beyer et al., 1987; Morgan and Morgan, 1988). Beyer

et al. (1987) noted that concentratio ns of phosphorus in soil had no effect.

# AX7-53 Nutritional Factors

Diet is a significant modifier of Pb absorp tion and of toxic effect s in many species of

birds and mammals (Eisler, 1988). Dietary deficiencies in calcium, zinc, iron, vitamin E, copper,

thiamin, phosphorus, magnesium, fat, protein, mi nerals, and ascorbic acid increased Pb

absorption and its toxic effects (Eisler, 1988).

Mateo et al. (2003b) studied in traspecies sensitivity to Pb-induced oxidative stress, by

varying the vitamin E content of mallard diets. Vitamin E can protect against peroxidative

damage and was found to decrease the lipid peroxidation in nerves of birds; how ever, it did not

alleviate any sign of the Pb poisoning. The au thors hypothesize that inhibition of antioxidant

enzymes and interaction with sulfhydryl groups of proteins may have a greater influence on Pb

toxicity than lipid peroxidati on (Mateo et al., 2003b). The e ffects observed by Mateo et al.

(2003b) were associated with very high concentrati ons of Pb in diet (1840 mg Pb/kg diet), much

higher than would be found gene rally in the environment, a nd high enough that the birds

decreased their food intake.

Mallard ducklings were exposed to Pb-contam inated sediment and either a low nutrition

or optimal nutrition diet (Dougl as-Stroebel et al., 2005). Le ad exposure combined with a

nutritionally inferior diet caused more changes in behavior (as measured by time bathing, resting,

and feeding) than Pb exposure or low-nutrition di et alone. These effects may be due to the lownutrition diet being deficient in le vels of protein, amino acids, calci um, zinc, and other nutrients.

Zebra finches ( Taeniopygia guttata ) were exposed to Pb-acetate via drinking water at

20 mg/L for 38 days, along with ei ther a low- or high-calcium diet (Snoeijs et al., 2005). Lead

uptake into tissues was enhanced by a low-calc ium diet. Lead did not affect body weight,

hematocrit, or adrenal stress response. Lead suppressed the humoral immune response only in

females on a low-calcium diet, suggesting increase d susceptibility of females to Pb (Snoeijs

et al., 2005).

Interactions with Other Pollutants

Lead can interact with other pollutants to ex ert toxicity in an an tagonistic (less than

additive), independent, additive, or synergistic (more than additive) manner. Concurrent

exposure to Pb and additional pollu tant(s) can affect the ability of plants to uptake Pb or the

other pollutant. However, the up take and toxic response of plants exposed to Pb combined with

# AX7-54 other metals is inconsistent (P åhlsson, 1989). Therefore, no gene ralizations can be made about

the relative toxicity of metal mixtures. For example, An et al. (2004) conducted acute, 5-day

bioassays on cucumber exposed to Pb, Pb + c opper, Pb + cadmium, or Pb + copper + cadmium

in a sandy loam soil of pH 4.3. Shoot and root growth were measured. Depending on the tissue

and metal combination, additivity, synergism, or antagonism was observed in the responses to

these metals. In fact, the response in roots was no t consistent with the re sponse in shoots for the

binary mixtures. However, the combined effects were greater in the roots than the shoots, which

may be explained by the tendency for Pb and other heavy metals to be retained in the roots of

plants. In addition, the pattern of metal bioaccumulation into plant tissue did not always

correlate with the toxic response. However, an tagonism was observed in the response of roots

and shoots exposed to all three metals, and this was reflected in the decreased accumulation of

metals into plant tissues. The authors hypothesized that this may be due to the formation of less

bioavailable metal complexes (An et al., 2004).

He et al. (2004) found that selenium and zinc both inhibited the uptake of Pb into Chinese

cabbage ( Brassica rapa ) and lettuce ( Lactuca sativa ). Zinc applied at 100 mg/kg or selenium

applied at 1 mg/kg decreased the uptake of Pb (p resent in soil at 10 mg /kg as Pb-nitrate) into

lettuce by 15% and 20%, respectively, and into Chinese cabbage by 23 and 20%, respectively.

Selenium compounds were evaluated to de termine whether they could change the

inhibition of ALAD in liver, kidne y, or brain of mice exposed to Pb-acetate (Perottoni et al.,

2005). Selenium did not affect the inhibition of ALAD in the kidney or liver, but it did reverse

the ALAD inhibition in mouse brain.

Co-occurrence of cadmium with Pb resulted in reduced blood Pb concentrations in rats

(Garcia and Corredor, 2004). The authors hypothe sized that cadmium ma y block or antagonize

the intestinal absorption of Pb, or the metallo thionein induced by cadmium may sequester Pb.

However, this was not observed in pigs, wher e blood Pb concentrations were greater when

cadmium was also administered (Phillips et al., 2003). The effect on growth rate also was

additive when both metals were given to young pigs (Phillip s et al., 2003).

# AX7-55 AX7.1.2.7 Summary

The current document expands upon and upda tes knowledge related to the uptake,

detoxification, physiological effect s, and modifying factors of Pb toxicity to terrestrial

organisms.

Surface Deposition onto Plants

Recent work (Dalenberg and Van Driel, 1990; Jones and Johnston, 1991; Angelova et al.,

2004) has supported previous results and conclu sions that surface deposition of Pb onto aboveground vegetation from airborne sources may be significant (U.S. Environmental Protection

Agency, 1986a). Similarly, it has been well documente d previously that Pb in soil also is taken

up by plants, although most remains in the roots, ther e is little translocatio n to shoots, leaves, or

other plant parts (U.S. Environmental Protecti on Agency, 1986a). More recent work continues

to support this finding (Sieghardt, 1990), and one study found increase d tolerance in species with

bulbs, possibly due to the storage of Pb in the bulb (Wierzbicka, 1999).

Uptake Mechanism into Plants

Lead was thought previously to be taken up by plants via th e symplastic route (through

cell membranes), although it was unknown whethe r some Pb also may be taken up via the

apoplastic route (between cells) (U.S. Environmental Protecti on Agency, 1986a). Recent work

has shown that the apoplastic ro ute of transport is stopped in th e primary roots by the endodermis

(Sieghardt, 1990), supporting the pr evious conclusion that the sy mplastic route is the most

significant route of tran sport into plant cells.

Species Differences in Uptake into Earthworms

Different species of earthworm accumulated di fferent amounts of Pb, and this was not

related to feeding strategy (U.S . Environmental Protection Agenc y, 1986a). This is supported by

recent work, which has shown Aporrectodea accumulated more than Lumbricus (Terhivuo et al.,

1994; Pižl and Josens, 1995), al though this is not consistent ly observed (Spurgeon and Hopkin,

1996a).

# AX7-56 Speciation and Form of Lead

Recent work supports previous conclusions that the form of metal tested, and its

speciation in soil, influence uptak e and toxicity to plants and in vertebrates (U.S. Environmental

Protection Agency, 1986a). The oxide form is less toxic that the chlori de or acetate forms,

which are less toxic than the ni trate form of Pb (Khan and Frankland, 1983; Lock and Janssen,

2002; Bongers et al., 2004). Howeve r, these results must be inte rpreted with caution, as the

counterion (e.g., the nitrate ion) may be contributing to the observed to xicity (Bongers et al.,

2004).

Detoxification in Plants

Lead may be deposited in root cell wa lls as a detoxificat ion mechanism (U.S.

Environmental Protection Agency, 1986a), and this may be influenced by calcium concentrations

(Antosiewicz, 2005). Yang et al. (2000) suggested that the oxalate content in root and root

exudates reduced the bioavailability of Pb in so il, and that this was an important tolerance

mechanism. Other hypotheses put forward recen tly include the presence of sulfur ligands

(Sharma et al., 2004) and the sequestration of Pb in old leaves (Szarek-L ukaszewska et al., 2004)

as detoxification mechanisms.

Detoxification in Invertebrates

Lead detoxification has not been studied ex tensively in invertebrates. Glutathione

detoxification enzymes were measured in two speci es of spider (Wilczek et al., 2004). Lead may

be stored in waste nodules in earthworms (H opkin, 1989) or as pyromorphite in the nematode

(Jackson et al., 2005).

Physiological Effects

The effects on heme synthesis (as meas ured by ALAD activity and protoporphyrin

concentration, primarily) have been well-documented (U.S. Environmental Protection Agency,

1986a) and continue to be studied (Schlick et al., 1983; Scheuhammer, 1989; Henny et al., 1991;

Redig et al., 1991; Beyer et al ., 2000; Hoffman et al., 2000a,b). However, Henny et al. (1991)

caution that changes in ALAD and other enzyme parameters are not always related to adverse

effects, but simply indicate exposure. Other effects on plasma enzymes, which may damage

# AX7-57 other organs, have been reported (Brar et al., 1997 a,b). Lead also may cause lipid peroxidation

(Mateo and Hoffman, 2001), which may be alle viated by vitamin E, although Pb poisoning may

still result (Mateo et al., 2003b). Changes in fatty acid production have been reported, which

may influence immune response and bone formation (Mateo et al., 2003a).

Response Modification

Genetics, biological factors, physical/environmental factors, nu tritional factors, and other

pollutants can modify terrestrial organism response to Pb. Fisher 344 rats were found to be more

sensitive to Pb than Sprague-Dawley rats (D earth et al., 2004). Y ounger animals are more

sensitive than older animals (E isler, 1988; Scheuhammer, 1991), and females generally are more

sensitive than males (Scheuhammer, 1987; Teje dor and Gonzalez, 1992; Snoeijs et al., 2005).

Monogastric animals are more sensitive than ruminants (Humphreys, 1991). Insectivorous

mammals may be more exposed to Pb than herb ivores (Beyer et al., 1985; Sample et al., 1998),

and higher tropic-level consumers may be less exposed than lower trophic-level organisms

(Henny et al., 1991). Diets defici ent in nutrients (including calc ium) result in increased uptake

of Pb (Snoeijs et al., 2005) and greater toxicity (Douglas-Stroebel et al., 2005) in birds, relative

to diets containing adequa te nutrient levels.

Mycorrhizal fungi may ameliorate Pb toxicity until a threshol d is surpassed (Malcova and

Gryndler, 2003), which may explain why some studies show increase d uptake into plants (Lin

et al., 2004) while others show no difference or less uptake (Di xon, 1988). Uptake of Pb into

plants and soil invertebrates increases with a de crease in soil pH. However, calcium content,

organic matter content, and ca tion exchange capacity of soil s also have had a significant

influence on uptake of Pb into plants and inve rtebrates (Beyer et al., 1987; Morgan and Morgan,

1988).

Interactions of Pb with other metals ar e inconsistent, depending on the endpoint

measured, the tissue analyzed, the animal species , and the metal combination (Phillips et al.,

2003; An et al., 2004; He et al ., 2004; Garcia and Corredor, 2004; Perottoni et al., 2005).



# AX7.1.3 Exposure-Response of Terrestrial Species

Section AX7.1.3 summarized the most important factors related to uptake of Pb by

terrestrial organisms, the physiological effects of Pb, and the factors th at modify terrestrial

# AX7-58 organism responses to Pb. Section AX7.1.4 ou tlines and highlights the critical recent

advancements in the understanding of the toxicity of Pb to terrestrial organisms. This section

begins with a summary of the conclusions from the 1986 Lead AQCD (U.S. Environmental

Protection Agency, 1986a) and then summarizes th e more recent critical research conducted on

effects of Pb on primary producer s, consumers, and decomposer s. All concentrations are

expressed as mg Pb/kg soil dw, unless otherwise indicated.

Lead exposure may adversely affect organisms at different levels of organization, i.e.,

individual organisms, populations, communities, or ecosystems. Generally, however, there is

insufficient information available for single mate rials in controlled studies to permit evaluation

of specific impacts on higher levels of organizatio n (beyond the individual organism). Potential

effects at the population level or higher are, of necessity, extrapolated from individual level

studies. Available population, community, or ecos ystem level studies are typically conducted at

sites that have been contaminated or adversely affected by multiple stressors (several chemicals

alone or combined with physical or biological stressors). Theref ore, the best documented links

between lead and effects on the environment are w ith effects on individual organisms. Impacts

on terrestrial ecosystems are discusse d in Section 7.1.5 and Annex AX7.1.5.

The summary of recent critical advancements in understanding toxicity relies heavily on

the work completed by a multi-stakeholder group, consisting of federal, state, consulting,

industry, and academic participants, led by the EP A to develop Ecological Soil Screening Levels

(Eco-SSLs). Eco-SSLs describe th e concentrations of contaminants in soils that would result in

little or no measurable effect on ecological r eceptors (U.S. Environmen tal Protection Agency,

2005a). They were developed by the U.S. EPA for use in screening-level assessments at

Superfund sites to identify contaminants requir ing further evaluation in an ecological risk

assessment and were not designed to be used as cleanup target levels. The Eco-SSLs are

intentionally conservative in orde r to provide confidence that c ontaminants, which could present

an unacceptable risk, are not screened out early in the evaluation process. That is, at or below

these levels, adverse effects are considered unl ikely. Eco-SSLs were derived for terrestrial

plants, soil invertebrates, birds, and mammals. Detailed procedur es using an ex tensive list of

acceptability and exclusion criteria (U.S. Enviro nmental Protection Agency, 2005a) were used in

screening the toxicity studies to ensure that only those that met minimum quality standards were

used to develop the Eco-SSLs. In addition, two peer reviews were completed during the

# AX7-59 Eco-SSL development process. The first was a consultation with the EPA Science Advisory

Board (SAB) in April 1999, and the second was a peer review workshop in July 2000, which was

open to the public.

Several conservative factors we re incorporated into the de velopment of the Eco-SSLs.

For the plant and invertebrate Eco-SSLs, st udies were scored to favor relatively high

bioavailability. For wildlife Eco-SSLs, only sp ecies with a clear exposure link to soil were

considered (generalist species, species with a link to the aquatic environment, or species which

consume aerial insects were excluded), simple diet classifications were used (100% plants, 100%

earthworms or 100% animal prey) when in reality wildlife consume a vari ed diet, species were

assumed to forage exclusively at the contaminated site, relative bioavailab ility or Pb in soil and

diet was assumed to be 1, and the TRV was sel ected as the geometric mean of NOAELs unless

this value was higher than the lowest bounded LOAEL for mortality, growth or reproduction

(U.S. Environmental Protection Agency, 2005a,b).

Areas of research that were not addressed are effects from irrelevant exposure conditions

relative to airborne emissions of Pb (e.g., Pb shot , Pb paint, injection st udies, studies conducted

on mine tailings, and studies conducted with hydr oponic solutions); mixture toxicity (addressed

in Section AX7.1.3); issues related to indirect ef fects (e.g., effects on pred ator/prey interactions,

habitat alteration, etc.); and human health-related research (e.g., hypertension), which is

addressed in othe r sections of this document.

The toxicity data presented herein should be reviewed w ith a note of caution regarding

their relevance to field conditions. Laboratory studies, partic ularly those using Pb-spiked soil,

generally do not allow the soil to equilibrate following the addition of Pb and prior to the

addition of test organisms. This may result in increased bioavailability and overestimation of Pb

toxicity relative to actual environmen tal conditions (Davies et al., 2003).

AX7.1.3.1 Summary of Conclusions from the 1986 Lead Criteria Document

The 1996 Lead AQCD, Volume II (U.S. Environmental Protection Agency, 1986a)

reviewed the literature on the toxicity of Pb to plants, soil organisms, birds, and mammals.

The main conclusions from that document are provided below.

# AX7-60 Primary Producers

Commonly reported effects of Pb on vascul ar plants include the inhibition of

photosynthesis, respiration, and/or cell elongation, all of which reduce plant growth. However, it

was noted that studies of other effects on plant processes such as maintenance, flowering, and

hormone development had not been conducted; therefore, no conclusion could be reached

concerning effects of Pb on these processes.

The EPA (U.S. Environmental Protection Ag ency, 1986a) concluded that most plants

experience reduced growth when Pb concentrati ons in soil moisture (the film of moisture

surrounding soil particles in the root zone of soil) exceed 2 to 10 mg/kg. It also was concluded

that most plants would experien ce reduced growth (inhibition of photosynthesis, respiration, or

cell elongation) in soils of ∃ 10,000 mg/kg when soil composition and pH are such that

bioavailability of Pb in the soil is low (see Section AX7.1.3 for details on factors affecting

bioavailability of Pb in soil). Acid soils or soils with low organic matter tend to increase Pb

bioavailability and would inhibit plants at mu ch lower Pb concentrations (e.g., as low as

<100 mg/kg).

Many effect levels have been reported at Pb concentrations much lower than

10,000 mg/kg soil. For example, effects on rye grass ( Lolium rigidum ) exposed to Pb in soil

included inhibition of germinating root elongatio n (at <2.5 mg/kg), absence of root growth

(at 5 mg/kg), or 55% inhibition of seed germin ation (at 20 to 40 mg/kg) . Stunted growth in

radish ( Raphanus sativus ) was observed at 1000 mg/kg soil, with complete growth inhibition at

5000 mg/kg, when Pb was added as Pb-chloride; e ffects were less severe when the Pb was added

as Pb-oxide.

Consumers

The EPA (U.S. Environmental Protection Ag ency, 1986a) concluded that food is the

largest contributor of Pb to animals, with inha lation rarely accounting for more than 10 to 15%

of daily intake of Pb and drinking water exposures being quite low. It al so was concluded that a

regular dose of 2 to 8 mg/kg-da y causes death in most animals. Grazing animals may consume

more than 1 mg/kg-day in habitats near sme lters and roadsides, but no toxic effects were

documented in these animals.

# AX7-61 Decomposers

Lack of decomposition has been observed as a particular problem around smelter sites.

Lead concentrations between 10,000 and 40,000 mg/kg soil can eliminate populations of

decomposer bacteria and fungi (U.S. Envir onmental Protection Agen cy, 1986a). Lead may

affect decomposition processes by direct toxici ty to specific groups of decomposers, by

deactivating enzymes excreted by decomposers to break down organic matter, or by binding with

the organic matter and rendering it resistan t to the action of decomposers.

Microorganisms are more sensitive than plants to Pb in soil. Delayed decomposition may

occur at between 750 and 7500 mg/kg soil (depe nding on soil type and other conditions).

Nitrification is inhibited by 14% at 1000 mg/kg soil.

U.S. Environmental Protection Agency Staff Review of 1986 Criteria Document

The EPA reviewed the 1986 Lead AQCD a nd presented an overall summary of

conclusions and recommendations (U.S. Enviro nmental Protection Agency, 1990). The major

conclusion was that available labora tory and field data indicated th at high concentrations of Pb

can affect certain plants and alter the compositi on of soil microbial communities. It was noted

that few field studies were available in which Pb exposures and associated effects in wildlife

were reported.

AX7.1.3.2 Recent Studies on the Effect s of Lead on Primary Producers

Several studies published since 1986 have reported terrestrial pl ant exposure to Pb in soil,

many of which were reviewed during the deve lopment of the Eco-SSLs (U.S. Environmental

Protection Agency, 2005b). The relevant info rmation from the Eco-SSL document (U.S.

Environmental Protection Agency, 2005b) is summari zed below. A literature search and review

also was conducted to identify critical papers published since 2002, which is when the literature

search was completed for Eco-SSL development, and no new papers were identified as critical to

the understanding of Pb toxicity to terrestrial primary producers.

Effects observed in studies conducted since the 1986 Lead AQCD are similar to those

reported previously and include decreased photos ynthetic and transpirati on rates and decreased

growth and yield (U.S. Envir onmental Protection Agency, 2005b). The phytotoxicity of Pb is

considered relatively low, due to the limited availability and uptake of Pb from soil and soil

# AX7-62 solution and minimal translocation of Pb from roots to shoots (Påh lsson, 1989). Although many

laboratory toxicity studies have reported effects on plants, there are few reports of phytotoxicity

from Pb exposure under field conditions. For ex ample, Leita et al. (1989) and Sieghardt (1990)

reported high concentrations of Pb and othe r metals in soil and ve getation collected around

mining areas in Europe, with no toxicity sy mptoms observed in plants or fruit.

The literature search complete d for the terrestrial plant Eco-SSL development identified

439 papers for detailed review, of which 28 me t the minimum criteria (U.S. Environmental

Protection Agency, 2005a). Thirty ecotoxicological endpoints were gleaned from these 28

papers and were further evaluated; most of those evaluate d growth (biomass), which was

considered the most sensitive and ecologically re levant endpoint (U.S. Environmental Protection

Agency, 2005b). Five of the endpoints, representi ng four species tested under three different

combinations of pH and organic matter content, were used to develop the Eco-SSL of 120 mg/kg

(115 mg/kg rounded to two significa nt digits) (Table AX7-1.3.1).

Table AX7-1.3.1. Plant Toxicity Da ta Used to Develop the Eco-SSL

Plant Species Soil pH % Organic

Matter Toxicity

Parameter Pb in Soil
(mg/kg dw)

Loblolly pine ( Pinus taeda ) 4 2.5 MATC * 

# (growth) 144

Red maple ( Acer rubrum ) 4 2.5 MATC (growth) 144

Berseem clover
( Trifolium alexandrium ) 6.3 0.94 MATC (growth) 316

Berseem clover 6.7 3.11 MATC (growth) 141

Rye grass ( Lolium rigidum ) 5.6 0.1 MATC (growth) 22

Geometric Mean 115

*MATC = Maximum Acceptable Threshold Concentrat ion, or the geometric mean of the NOAEC
(no-observed-adverse-effect concentration) and LOAE C (lowest-observed-adverse-effect concentration).

Source: U.S. Environmental Protection Agency (2005b).



# The 25 ecotoxicological endpoints that were no t used to develop the Eco-SSL for plants

are presented in Table AX7-1.3.2. The first six e ndpoints were considered eligible for Eco-SSL

derivation but were not used; the remainder did not meet all of the requirements to be considered

for inclusion in the Eco-SSL derivation process.

# AX7-63 Table AX7-1.3.2. Plant Toxicity Data Not Used to Develop the Eco-SSL

Plant Species Soil pH % Organic

Matter Toxicity Parameter Pb in Soil
(mg/kg dw)

Studies eligible for Eco-SSL derivation, but not used

Berseem clover
( Trifolium alexandrium ) 6.7 3.11 MATC 141

Tomato
( Lycopericon esculentum ) 7.73 1.70 MATC 71

Tomato 8.20 0.86 MATC 71

Fenugreek
( Trigonella foenum-graecum ) 8.3 0.5 MATC 283

Spinach ( Spinacea oleracea ) 6.7 3.0 MATC 424

Corn ( Zea mays ) 6.5 2.1 MATC 158

Sow thistle ( Sonchus oleraceus ) 7.23 1.6 MATC 2,263

Studies not eligible for Eco-SSL derivation

Loblolly pine ( Pinus taeda ) 5.5 3.4 NOAEC 480

Red oak ( Quercus rubra ) 6 1.5 LOAEC 100

Spinach 6.7 0.0 NOAEC 600

Alfalfa ( Medicago sativa ) 6.4 1.0 NOAEC 250

Alfalfa 6.9 1.7 NOAEC 250

Alfalfa 6.9 1.7 NOAEC 250

Radish ( Raphanus sativus ) 6.9 1.0 LOAEC 500

Radish 6.9 1.0 LOAEC 100

Radish 6.9 1.0 LOAEC 100

Onion ( Allium cepa ) 8.3 0.5 LOAEC 50

Radish 5.1 8.0 NOAEC 600

Carrot ( Daucus carota ) 7.0 0.6 NOAEC 85

Peas ( Pisum sativum ) 7.0 0.6 NOAEC 85

Barley ( Hordeum vulgare ) 6.0 2.5 NOAEC 1,000

Alfalfa 6.9 4.8 NOAEC 250

Tomato 7.45 2.06 MATC 35

Spinach 6.7 8.0 NOAEC 600

Radish 6.2 8.0 NOAEC 600

Radish 7.1 8.0 NOAEC 600

*MATC = Maximum Acceptable Threshold Concentr ation, or the geometric mean of the NOAEC
(no-observed-adverse-effect concentration) and L OAEC (lowest-observed-advers e-effect concentration).

Source: U.S. Environmenta l Protection Agency (2005b).

# AX7-64 AX7.1.3.3 Recent Studies on the E ffects of Lead on Consumers

Since the 1986 Lead AQCD (U.S. Environmen tal Protection Agency, 1986a), there have

been several studies in which birds and mammals were exposed to Pb via ingestion (primarily

through dietary Pb). Many of these were reviewed during development of the Eco-SSLs (U.S.

Environmental Protection Agency, 2005b). The relevant information from the Eco-SSL

document (U.S. Environmental Protection Agenc y, 2005b) is described below. A literature

search and review was conducted to identify cr itical papers publishe d since 2002. These recent

critical papers are described briefly below. No studies were found that used inhalation exposures

to evaluate endpoints such as survival, growth, and reproduction in birds or mammals. All

studies described below exposed organisms via i ngestion (drinking water or diet) or gavage.

The Eco-SSLs for avian and mammalian consumers are presented as Pb concentrations in

soil. These concentrations were calculated by assuming exposure to Pb via incidental soil

ingestion and ingestion of Pb-contaminated food, and using a NOAEL as the TRV (U.S.

Environmental Protection Agency, 2005a). A s implified version of the equation used to

calculate the Eco-SSL is:



# ( ) 

# ( ) 

# [ ]

TRV BW IRCIRC HQ food food soil soil 

# ÷×+×

=

where:
HQ = hazard quotient (1 mg Pb/kg bw/day)

C soil 

# = concentration of Pb in soil (mg Pb/kg soil)

IR soil 

# = incidental soil ingestion rate (kg soil/day)

C food 

# = concentration of Pb in food (mg Pb/kg food)

IR food 

# = food ingestion rate (kg food/day)

BW = body weight (kg)

TRV = toxicity referen ce value (mg Pb/kg bw/day)

Food ingestion was estimated by modeling the uptake of Pb from soil into each diet

component (e.g., vegetation, invertebrates, etc.). Bioavailability of Pb in soil and food was

assumed to be 100%. The Eco-SSL is equivalent to the concentration of Pb in soil that results in

an HQ = 1. The two factors that may have the most significant influe nce on the resulting EcoSSL are the assumption of 100% bioa vailability of Pb in soil and diet and the selection of the (AX7-4)

# AX7-65 TRV. The toxicity data that were reviewed to develop the TRV are presented in the following

subsections.

Representative avian and mammalian wildlife species were selected for modeling Pb

exposures to wildlife with di fferent diets and calculating the Eco-SSL. The avian species

selected were dove (herbivore), woodcock (insec tivore), and hawk (carnivore). The mammalian

species selected were vole (her bivore), shrew (insectivore), and weasel (carnivore). The lowest

of the three back-calculated soil concentrations, which resulted in an HQ = 1, was selected as the

Eco-SSL. For Pb, the lowest values were for the insectivorous species of bird and mammal.

Avian Consumers

Effects on birds observed in studies conducted since the 1986 Lead AQCD (U.S.

Environmental Protection Agency, 1986a) are similar to those reported previously: mortality,

changes in juvenile growth ra te and weight gain, effects on various reproductive measures, and

changes in behavior (U.S. Environmental Pr otection Agency, 2005b). Reproductive effects

following Pb exposure included declines in clut ch size, number of young hatched, and number of

young fledged as well as decreased fertility or eg gshell thickness. Few significant reproductive

effects have been reported in birds at Pb concentrations below 100 mg/kg in the diet

(Scheuhammer, 1987).

The literature search completed for Eco-SSL development identified 2,429 papers for

detailed review for either avian or mammalian sp ecies, of which 54 met the minimum criteria for

further consideration for avian Eco-SSL develo pment (U.S. Environmental Protection Agency,

2005b). The 106 toxicological data points for bi rds that were further evaluated included

biochemical, behavioral, physiological, pathological, reproductive, growth, and survival effects.

Growth and reproduction data were used to derive the Eco-SSL (Table AX7-1.3.3;

Figure AX7-1.3.1). The geometric mean of the NOAELs was calculated as 10.9 mg/kg-day,

which was higher than the lowest bounded L OAEL (the term “bounded” means that both a

NOAEL and LOAEL were obtained from the same study). Therefore, the highest bounded

NOAEL that was lower than the lowest bounded LOAEL for survival, growth, or reproduction

(1.63 mg Pb/kg bw-day) was used as the TRV (U.S. Environmental Protection Agency, 2005b).

The TRV was used to back-calculate the Eco- SSL of 11 mg/kg soil for avian species (U.S.

# AX7-66Table AX7-1.3.3. Avian Toxicity Data Used to Develop the Eco-SSLAvianSpeciesNo. ofDosesRoute ofExposureExposureDurationDurationUnitsAgeAgeUnitsLifestage SexEffectTypeEffectMeasureResponseSiteNOAEL(mg/kgbw/day)LOAEL(mg/kgbw/day)ReproductionJapanesequail4 FD 5 w 6 wLBF REP PROG WO 0.194 1.94Chicken 3 FD 4 w NR NR LB F REP PROG WO 1.63 3.26Chicken 4 FD 30 d 22 w LB F EGG ALWT EG 2.69 4.04Mallard 2 FD 76 d NR NR SM F EGG ESTH EG 5.63Americankestrel3 FD 6 mo 1-6 yr AD F REP RSUC WO 12.0Japanesequail5 FD 5 w 6 d JV M REP TEWT TE 12.6 126Japanesequail5 FD 5 w 1 d JV M REP TEWT TE 67.4 135Japanesequail3 FD 32 d NR NR AD F REP PROG WO 125Japanesequail5 FD 12 w 0 d LB B REP EGPN EG 0.110Japanesequail4 FD 12 w NR NR LB F REP PROG WO 0.194Chicken 5 FD 10 w NR NR LB F REP PROG WO 3.26Ringedturtle dove2 DR 11 w NR NR AD M REP TEWT TE 11.8Japanesequail2 FD 1 w 14 w JV F REP TPRD WO 93.1Japanesequail2 FD 27 d NR NR AD F REP PROG WO 377

# AX7-67Table AX7-1.3.3 (cont’d). Avian Toxicity Data Used to Develop the Eco-SSLAvianSpeciesNo. ofDosesRoute ofExposureExposureDurationDurationUnitsAgeAgeUnitsLifestage SexEffectTypeEffectMeasureResponseSiteNOAEL(mg/kgbw/day)LOAEL(mg/kgbw/day)GrowthJapanesequail3 FD 5 w 1 d JV F GRO BDWT WO 1.56 15.6Japanesequail3 FD 2 w 1 d JV B GRO BDWT WO 2.77Japanesequail2 FD 2 w 1 d JV NR GRO BDWT WO 4.64Japanesequail3 FD 4 w 0 d JV F GRO BDWT WO 5.93 59.3Chicken 4 FD 4 w 4 w JV NR GRO BDWT WO 6.14 61.4Chicken 4 FD 4 w 4 w JV NR GRO BDWT WO 7.10 71.0Japanesequail5 FD 12 w 0 d JV F GRO BDWT WO 11.1 111Japanesequail5 FD 12 w 1 w JV F GRO BDWT WO 11.2 112Japanesequail5 FD 2 w 6 d JV NR GRO BDWT WO 12.6 126Japanesequail5 FD 1 w 1 d JV NR GRO BDWT WO 13.5 67.4Chicken 2 FD 21 d 1 d JV B GRO BDWT WO 14.2Duck 3 GV 3 mo 24 w MA F GRO BDWT WO 20.0Americankestrel4 GV 10 d 1 d JV NR GRO BDWT WO 25.0 125Chicken 2 FD 20 d 1 d JV B GRO BDWT WO 28.4Japanesequail5 FD 14 d 1 d JV B GRO BDWT WO 34.5

# AX7-68Table AX7-1.3.3 (cont’d). Avian Toxicity Data Used to Develop the Eco-SSLAvianSpeciesNo. ofDosesRoute ofExposureExposureDurationDurationUnitsAgeAgeUnitsLifestage SexEffectTypeEffectMeasureResponseSiteNOAEL(mg/kgbw/day)LOAEL(mg/kgbw/day)Americankestrel4 FD 60 d 1-2 yr AD B GRO BDWT WO 54.3Chicken 5 FD 2 w 1 d JV M GRO BDWT WO 61.3 123Mallard 4 FD 8 d 9 d JV NR GRO BDWT WO 66.9Chicken 5 FD 20 d 1 d JV M GRO BDWT WO 38.2Chicken 2 FD 3 w 1 d JV M GRO BDWT WO 53.1Japanesequail3 FD 32 d NR NR AD F GRO BDWT WO 64.3Chicken 2 FD 19 d 1 d JV M GRO BDWT WO 76.3Chicken 3 FD 2 w 1 d JV M GRO BDWT WO 124Chicken 4 FD 14 d 8 d JV M GRO BDWT WO 152Chicken 2 FD 20 d 1 d JV M GRO BDWT WO 163Chicken 2 OR 4 w NR NR JV B GRO BDWT WO 200Chicken 2 FD 7 d 1 d JV M GRO BDWT WO 262Chicken 2 FD 2 w 1 d JV M GRO BDWT WO 270Chicken 2 FD 7 d 1 d IM NR GRO BDWT WO 273Chicken 2 FD 14 d 8 d JV M GRO BDWT WO 282AD = adult; ALWT = albumin weight; B = both; BDWT = body weight changes; d = days; DR = drinking water; EG = egg; EGG = effectson eggs; EGPN = egg production; ESTH = eggshellthinning; F = female; FD = food; GRO = growth; GV = gavage; JV =juvenile; LB = laying bird; MA = mature; M = male; mo = months; NR = not reported; OR = other oral; PROG = progeny countsor numbers; REP = reproduction; RSUC = reproductive success; SM = sexually mature; TE= testes; TEWT = testes weight; TPRD = total production; w = weeks; WO =whole organism; yr = years.Source: U.S. Environmental Protection Agency (2005b)

# AX7-69 Figure AX7-1.3.1. Avian reproduction and gr owth toxicity data considered in
development of the Eco-SSL.

Source: U.S. Environmental Protection Agency (2005b).



# Environmental Protection Agency, 2005b). For more information on the rationale for selecting

TRVs, please refer to U.S. Environmental Protection Agency (2003).

Many of the toxicity data presented in the Eco-SSL document (U.S. Environmental

Protection Agency, 2005b) are lower than those discussed in the 1986 Lead AQCD. The TRV

and resulting Eco-SSL were derived using many conservative assumptions. For example, the

EPA (U.S. Environmental Protecti on Agency, 2005b) recognizes that toxicity is observed over a

wide range of doses (<1 to >100 mg Pb/kg bw/d ay), even when considering only reproductive

effects in the same species. In addition, the TR V of 1.63 mg/kg-day is lower than most of the

reported doses that have been associated with measured effects. This is true for not only

survival, growth, and reproductive effects but also biochemical, behavi oral, physiological, and

pathological effects, which gene rally are observed at lo wer concentrations than effects on growth

or reproduction. In addition, the Eco-SSL was back-calculated using conservative modeling

assumptions. Therefore, the Eco-SSL of 11 mg/ kg may be considered a conservative value.

# AX7-70 Very little research has been done to expand the knowledge of the toxicity of Pb to birds

since the Eco-SSL work was done. However, severa l studies have been c onducted on waterfowl.

Toxicity data for waterfowl (in particular, mallards) were included in the soil Eco-SSL

development process (Table AX7-1.3.3), alt hough mallards may be more exposed to

contaminants in sediment than soil. Effects on waterfowl may vary depending on the form of Pb,

characteristics of the sediment, the foraging st rategy of the species (w hich may vary during

reproduction), and the nutritional st atus of the animal. Sediment is recognized as an important

route of exposure for waterfowl, particularly those species that da bble (i.e., forage on

invertebrates in the sediment) (Beyer et al ., 2000; Douglas-Stroebel etal., 2005). DouglasStroebel et al. (2005) found that mallard ducklin gs exposed to Pb-contaminated sediment and a

low nutrition diet exhibited more changes in be havior (as measured by time bathing, resting, and

feeding) than Pb exposure or low nutrition exposu re alone. These effects may be due to the low

nutrition diet being deficient in le vels of protein, amino acids, calci um, zinc, and other nutrients.

Beyer et al. (2000) related blood Pb to subl ethal effects in wate rfowl along the Coeur

d
= Alene River near a mining site in Idaho. The authors suggeste d that 0.20 mg/kg ww blood Pb

represents the no-effect level. This no-effect blood concentra tion corresponds to a sediment Pb

concentration of 24 mg/kg. A sediment concentr ation of 530 mg/kg, associated with a blood Pb

concentration of 0.68 mg/kg ww, is suggested to be the lowest-effect concentration. These

results are consistent with those of Scheuhamm er (1989) who found blood Pb concentrations of

0.18 μg/mL to 0.65 μg/mL in mallards corresponded to conditions associated with greater than

normal exposure to Pb, but that that should not be considered Pb poisoning. The study by Beyer

et al. (2000) related blood Pb to waterfowl mortality and concl uded that some swan mortality

may occur at blood Pb levels of 1.9 mg/kg ww, co rresponding to a sediment Pb concentration of

1800 mg/kg. Using the mean blood level of 3.6 mg/kg ww from all moribund swans in the

study, it was predicted that half of the swans c onsuming sediment at th e 90th percentile rate

would die with chronic exposure to sedi ment concentrations of 3600 mg/kg.

Mammalian Consumers

Effects on mammals observed in studies conducted since the 1986 Lead AQCD (U.S.

Environmental Protection Agency, 1986a) are similar to those reported previously: mortality,

effects on reproduction, developmental effects, and changes in growth (U.S. Environmental

# AX7-71 Protection Agency, 2005b). Very little research has been done to expand the knowledge of the

toxicity of Pb to mammalian wildlife, sin ce the Eco-SSL work was done. Most studies

conducted on mammals use laboratory animals to study potential adverse effects of concern for

humans, and such studies are summarized in other sections of this document.

Of the 2,429 papers identified in the literature search fo r Eco-SSL development, 219 met

the minimum criteria for further considera tion for mammalian Eco-SSL development (U.S.

Environmental Protection Agency, 2005b). Th e 343 ecotoxicological endpoints for mammals

that were further evaluated included bioche mical, behavioral, physiological, pathological,

reproductive, growth, and survival effects. Grow th and reproduction data were used to derive

the Eco-SSL (Table AX7-1.3.4, Figure AX7-1.3.2). The geometric mean of the NOAELs was

calculated as 40.7 mg/kg-day, wh ich was higher than the lowe st bounded LOAEL for survival,

growth, or reproduction. Theref ore, the highest bounded NOAEL th at was lower than the lowest

bounded LOAEL for survival, growth, or reproduc tion (4.7 mg Pb/kg bw-day) was used as the

TRV (U.S. Environmental Protec tion Agency, 2005b). The TRV was used to back-calculate the

Eco-SSL of 56 mg/kg soil (U.S. Environmen tal Protection Agency, 2005b). For more

information on the rationale for selecting TRVs, please refer to U.S. Environmental Protection

Agency (2003).

A review of the data presented in the Ec o-SSL document (U.S. Environmental Protection

Agency, 2005b) reveals that effects on survival generally are obser ved at Pb doses much greater

than those reported in the 1986 Lead AQCD, wher e it was concluded that most animals would

die when consuming a regular dose of 2 to 8 mg Pb/kg bw-day (U.S. Environmental Protection

Agency, 1986a). However, the data presented in the Eco-SSL document (U.S. Environmental

Protection Agency, 2005b) generally do not support this. While five studies reported decreased

survival at these levels, 34 ot her studies reported no mortalit y or a LOAEL for mortality at

significantly higher doses (U.S. Environmental Pr otection Agency, 2005b). Th e five studies that

supported this low toxic level we re conducted on three species (m ouse, rat, and cow) and used

either gavage or drinking wate r as the exposure method. The 34 other studies included data on

these three species as well as five other spec ies (rabbit, dog, pig, hamster, and shrew) and

included gavage and drinking water as well as food ingestion exposure methods. The NOAELs

for survival ranged from 3.5 to 3200 mg/kg-da y (U.S. Environmental Protection Agency,

2005b). Therefore, the review of data in the Eco-SSL document s uggests effects on survival of

# AX7-72Table AX7-1.3.4. Mammalian Toxicity Data Used to Develop the Eco-SSLMammalianSpeciesNo. ofDosesRoute ofExposureExposureDurationDurationUnits AgeAgeUnits Lifestage SexEffectTypeEffectMeasureResponseSiteNOAEL(mg/kgbw/day)LOAEL(mg/kgbw/day)ReproductionRat 5 DR 62 d 21 d GE FREPPRWT WO 0.71 7.00Rat 6 DR 21 d NRNR GE FREPPRWT WO 1.00 5.00Rat 3 DR 35 d NRNR AD MREPRSUC WO 2.60 26.0Rat 4 DR 62 d 21 d GE BREPPRWT WO 3.00 6.0Sheep 3 FD 27 w NR NR GE F REP RSUC WO 4.50 —Rat 6 DR 21 d NRNR GE FREPPRWT WO 5.00 10.0Guinea pig3 DR40d NR NR GE F REP PRWT WO 5.50 —Rat 5 FD 92 w 21 d JV MREPTEWT TE 7.50 74.9Rat 4 DR 23.8 d 21 d LC FREP Other WO 8.90Rat 5 DR 23.8 d 21 d GE FREP Other WO 9.10 45.0Cotton rat3 DR7w NR NR AD M REP RHIS RT 12.4 170Rat 4 GV 9 w 10 w JV MREPSPCV TE 18.0 180Rat 3 DR 100 d 21 d GE FREPPRWT WO 25.4 —Rat 2 FD 35 d 70 d LC FREPPRWT WO 27.5 —Rat 4 DR 60 d NRNR SM MREPTEWT TE 31.6 63.2Rat 4 DR 56 d 70 d LC FREPPROG WO 32.5 —Rat 3 DR 31 d NRNR LC FREPPRWT WO 33.3 111Rat 4 GV 41 d NRNR GE FREPPRWT WO 41.0 54.6Rat 5 DR 1 w 94 d JV MREPSPCL SM 47.3 82.0Rat 4 DR 30 d NRNR SM MREP Other SV 56.0 285

# AX7-73Table AX7-1.3.4 (cont’d). Mammalian Toxicity Data Used to Develop the Eco-SSLMammalianSpeciesNo. ofDosesRoute ofExposureExposureDurationDurationUnitsAgeAgeUnitsLifestage SexEffectTypeEffectMeasureResponseSiteNOAEL(mg/kgbw/day)LOAEL(mg/kgbw/day)Hamster 2 DR 51 d 15 w GE F REP PROG WO 64.8 —Hamster 2 DR 14 d 11 w GE F REP PROG WO 64.9 —Rat 4 DR 37 d NR NR GE FREP PRWT WO 90.1 270Rat 5 GV 12 d NR NR GE F REP RSEM EM 100 150Rat 3 DR 68 d 25 d GE FREP PRWT WO 115 —Rat 4 DR 77 d 25 d GE FREP PRWT WO 116 —Rat 2 DR 21 d NR NR LC FREP PRWT WO 120 —Mouse 3 FD 8 w 2 mo GE M REP SPCV TE 144 1,440Mouse 7 FD 30 d NR NR LC F REP PRWT WO 202 506Mouse 7 FD 30 d NR NR LC F REP PRWT WO 202 506Rat 4 DR 21 d NR NR GE FREP DEYO WO 276 552Rat 5 DR 10 w NR NR AD MREP TEWT MT 294 587Rat 2 GV 102 d 30 d GE FREP PRWT WO 441 —Rat 2 DR 9 mo NR NR SM MREP RHIS TE 600 —Rat 4 FD 4 d NR NR LC FREP PRWT WO 601 1,500Rat 4 DR 13 w NR NR JV MREP FERT WO 639 —Mouse 4 GV 60 d NR NR AD F REP RPRD OV — 2.00Rat 3 FD 339 d 26-27 d JV BREP PRWT WO — 2.49Rat 2 DR 9 mo 21 d JV F REP DEYO WO — 2.94Mouse 2 DR 6 mo 21 d JV F REP DEYO WO — 3.62Mouse 4 GV 52 d 2 mo GE F REP PROG EM — 5.50Rat 2 DR 120 d 1 d GE M REP SPCL TE — 6.76

# AX7-74Table AX7-1.3.4 (cont’d). Mammalian Toxicity Data Used to Develop the Eco-SSLMammalianSpeciesNo. ofDosesRoute ofExposureExposureDurationDurationUnitsAgeAgeUnitsLifestage SexEffectTypeEffectMeasureResponseSiteNOAEL(mg/kgbw/day)LOAEL(mg/kgbw/day)Mouse 2 DR 5 w NR NR AD M REP TEDG TE — 16.6Mouse 2 GV 2 w NR NR JV M REP SPCL SM — 46.4Rat 2 FD 102 d NR NR GE FREP PROG WO — 49.6Rat 2 GV 3 mo 8 w SM MREP TEDG TE — 50.0Rat 2 DR 18 d NR NR GE FREP PRWT WO — 55.5Rat 3 DR 90 d NR NR AD M REP SPCL SM — 61.2Mouse 2 DR 23 d NR NR GE F REP PRWT WO — 78.6Mouse 2 DR 62 d NR NR GE F REP PRWT WO — 99.8Mouse 2 DR 18 w 6-8 w LC F REP PRWT WO — 137Mouse 2 DR 12 w 9 w SM M REP PRFM WO — 139Mouse 4 FD 18 d NR NR GE F REP PRWT WO — 154Rat 2 DR 4 w 99 d JV MREP SPCL SM — 171Rat 5 DR 6 w 4 moGE FREP RHIS WO — 175Rat 2 DR 22 d NR NR GE FREP PRWT WO — 178Rat 3 DR 30 d 52 d JV MREP GREP PG — 198Rat 2 DR 13 w NR NR GE FREP PRWT WO — 200Rat 2 DR 21 d 80 d JV FREP PRWT WO — 218Rat 4 FD 3 w NR NR LC FREP PRWT WO — 221Rat 2 FD 1 w 19 w LC F REP PRWT WO — 222Rat 4 FD 3 w NR NR LC FREP PRWT WO — 230Rat 3 FD 25 d NR NR LC FREP PRWT WO — 258Rat 2 DR 21 d NR NR LC FREP PRWT WO — 330

# AX7-75Table AX7-1.3.4 (cont’d). Mammalian Toxicity Data Used to Develop the Eco-SSLMammalianSpeciesNo. ofDosesRoute ofExposureExposureDurationDurationUnitsAgeAgeUnitsLifestage SexEffectTypeEffectMeasureResponseSiteNOAEL(mg/kgbw/day)LOAEL(mg/kgbw/day)Rat 2 DR 30 d 52 d JV MREP SPCL SM — 354Rat 2 DR 17 d NR NR GE FREP PRWT WO — 360Rat 2 DR 24 d NR NR LC FREP PRWT WO — 360Rat 2 DR 12 d NR NR GE FREP PRWT WO — 362Rat 2 DR 30 d 27 d JV MREP SPCL SM — 364Mouse 2 DR 44 d NR NR GE F REP PRWT WO — 381Mouse 2 DR 14 d NR NR LC F REP PRWT WO — 381Rat 2 DR 50 d 24 d JV FREP RBEH WO — 381Mouse 2 DR 45 d 50-100 d GE F REP ODVP WO — 404Rat 2 DR 22 d NR NR GE FREP PRWT WO — 420Mouse 2 DR 48 d NR NR GE F REP PRWT WO — 437Rat 2 DR 9 mo 3 mo SM MREP SPCL TE — 579Rat 2 DR 9 mo NR NR SM MREP TEDG TE — 600Rat 2 DR 3 w 14 w LC FREP PRWT WO — 635Mouse 2 FD 7 d NR NR GE F REP RSUC EM — 646Rat 2 DR 126 d 1 d GE FREP PROG WO — 651Rat 2 DR 20 w 10 w GE FREP PRWT WO — 750Mouse 2 DR 4 d NR NR LC F REP PRWT WO — 762Rat 2 FD 2 w NR NR LC FREP PRWT WO — 828Rat 2 FD 7 d NR NR LC FREP PRWT WO — 833Rat 2 FD 21 d NR NR LC FREP PRWT WO — 991Mouse 4 DR 18 w 11 w JV F REP TEWT WO — 1,370

# AX7-76Table AX7-1.3.4 (cont’d). Mammalian Toxicity Data Used to Develop the Eco-SSLMammalianSpeciesNo. ofDosesRoute ofExposureExposureDurationDurationUnitsAgeAgeUnitsLifestage SexEffectTypeEffectMeasureResponseSiteNOAEL(mg/kgbw/day)LOAEL(mg/kgbw/day)Rat 2 FD 30 d NR NR LC FREP PRWT WO — 1,770Mouse 2 DR 14 w NR NR GE B REP PROG WO — 1,990Rat 2 FD 16 d NR NR LC FREP PROG WO — 2,570Rat 2 FD 7 d NR NR LC FREP PRWT WO — 2,570Rat 2 FD 25 d NR NR LC FREP PRWT WO — 2,570Rat M FD 27 d NR NR LC C REP PROG WO — 2,840Mouse 2 DR 14 w 21 d JV B REP PROG WO — 3,630Rat 2 FD 17 d NR NR LC FREP PRWT WO — 6,170GrowthHorse 2 FD 15 w 20-21 w JV M GRO BDWT WO 0.15 —Rat 2 FD 21 d 0 d JV FGROBDWT WO 0.5 —Rat 6 DR 21 d NR NR GE FGROBDWT WO 1.00 5.00Rat 5 DR 7 d 50 d AD FGROBDWT WO 1.27 13.0Cattle 4 OR 7 w 1 w JV M GRO BDWT WO 1.99 —Rat 3 DR 14 d 21 d JV FGROBDWT WO 2.40 —Rat 2 DR 332 d 28 d JV BGROBDWT WO 2.98 —Rat 4 DR 7 w 21 d GE FGROBDWT WO 4.70 8.90Dog 3 FD 7 mo NR NR JV NRGRO BDWT WO 4.71 —Rat 3 DR 30 d 22-24 d JV MGROBDWT WO 5.64 28.2Rat 4 DR 23 d 22 d JV FGROBDWT WO 5.80 29.0Cattle 3 OR 84 d NR NR JV M GRO BDWT WO 7.79 —Rat 2 OR 6 w NR NR AD MGROBDWT WO 9.10 —

# AX7-77Table AX7-1.3.4 (cont’d). Mammalian Toxicity Data Used to Develop the Eco-SSLMammalianSpeciesNo. ofDosesRoute ofExposureExposureDurationDurationUnitsAgeAgeUnitsLifestage SexEffectTypeEffectMeasureResponseSiteNOAEL(mg/kgbw/day)LOAEL(mg/kgbw/day)Rat 2 GV 8 w NR NR JV FGROBDWT WO 10.0 —Rat 3 DR 6 mo NR NR AD MGROBDWT WO 10.6 532Rabbit 3 GV 10 d 1 d JV F GRO BDWT WO 10.7 50.4Rat 2 DR 140 d 21 d JV MGROBDWT WO 10.7 —Rat 2 DR 6 w NR NR JV MGROBDWT WO 15.1 —Rat 2 FD 10 w NR NR JV MGROBDWT WO 15.4 —Rat 2 OR 6 w NR NR AD MGROBDWT WO 15.5 —Rat 2 DR 7 w NR NR JV MGROBDWT WO 16.1 —Mouse 3 DR 14 d 0 d JV NR GRO BDWT WO 16.3 163Rat 4 GV 9 w 10 w JV MGROBDWT WO 18.0 180Rat 3 FD 339 d 26-27 d JV BGROBDWT WO 18.3 —Rat 4 GV 29 d NR NR SM FGROBDWT WO 18.9 —Rat 7 DR 10 w NR NR JV MGROBDWT WO 24.3 —Rat 4 DR 56 d 70 d LC FGROBDWT WO 32.5 —Sheep 5 FD 84 d NR NR JV M GRO BDWT WO 32.7 —Rat 2 DR 10 w NR NR JV MGROBDWT WO 38.5 —Cattle 4 FD 7 w 16 w JV M GRO BDWT WO 43.0 —Rat 2 GV 28 d 2 d JV BGROBDWT WO 50.0 —Rat 5 DR 4 w 94 d JV MGROBDWT WO 71.5 178Rat 4 GV 12 d 2 d JV BGROBDWT WO 75.0 225Rat 2 FD 4 w NR NR JV MGROBDWT WO 100 —Rat 6 DR 10 w NR NR JV MGROBDWT WO 120 383

# AX7-78Table AX7-1.3.4 (cont’d). Mammalian Toxicity Data Used to Develop the Eco-SSLMammalianSpeciesNo. ofDosesRoute ofExposureExposureDurationDurationUnitsAgeAgeUnitsLifestage SexEffectTypeEffectMeasureResponseSiteNOAEL(mg/kgbw/day)LOAEL(mg/kgbw/day)Mouse 3 FD 4 w 3 mo JV B GRO BDWT WO 136 1360Mouse 2 DR 18 w 6-8 w LC F GRO BDWT WO 137 —Mouse 2 DR 12 w NR NR GE M GRO BDWT WO 139 —Rat 3 DR 30 d 52 d JV MGROBDWT WO 169 508Rat 2 DR 4 w 99 d JV BGROBDWT WO 171 —Rat 4 GV 18 d 3 d JV MGROBDWT WO 180 —Mouse 3 DR 6 w 7 w SM M GRO BDWT WO 187 373Rat 4 GV 18 d 2 d JV BGROBDWT WO 200 —Rat 2 GV 91 d NR NR JV MGROBDWT WO 200 —Rat 2 DR 21 d 80 d JV FGROBDWT WO 218 —Rat 4 FD 1 w NR NR LC FGROBDWT WO 230 460Rat 4 DR 30 d NR NR JV MGROBDWT WO 285 —Mouse 5 DR 10 w NR NR JV M GRO BDWT WO 362 —Rat 2 DR 30 d 52 d JV MGROBDWT WO 364 —Rat 4 GV 14 d 14 d JV NR GRO BDWT WO 400 800Rat 5 GV 14 d 20 d JV NR GRO BDWT WO 400 800Rat 2 FD 14 mo 0 d JV NRGROBDWT WO 431 —Rat 2 GV 102 d 30 d LC FGROBDWT WO 441 —Mouse 4 GV 12 d 6 d JV M GRO BDWT WO 534 —Mouse 7 FD 30 d NR NR LC F GRO BDWT WO 632 1264Rat 2 DR 126 d 1 d GE FGROBDWT WO 651 —Rat 2 DR 20 w 10 w GE FGROBDWT WO 750 —

# AX7-79Table AX7-1.3.4 (cont’d). Mammalian Toxicity Data Used to Develop the Eco-SSLMammalianSpeciesNo. ofDosesRoute ofExposureExposureDurationDurationUnitsAgeAgeUnitsLifestage SexEffectTypeEffectMeasureResponseSiteNOAEL(mg/kgbw/day)LOAEL(mg/kgbw/day)Mouse 7 FD 28 d NR NR LC F GRO BDWT WO 1260 2530Rat 4 FD 18 d NR NR LC FGROBDWT WO 1500Rat 2 DR 9 d 21 d JV MGROBDWT WO — 3.30Cattle 2 FD 283 d 7 mo JV M GRO BDWT WO — 15.0Rat 3 DR 92 d 25 d GE FMPHGMPH TB — 28.7Rat 4 DR 7 d 25 d GE FGROBDWT WO — 29.0Rat 2 DR 5 d 26 d JV FGROBDWT WO — 29.0Rat 2 DR 26 d 22 d JV FGROBDWT WO — 29.5Rat 2 DR 14 d 26 d JV FMPH Other TA — 29.9Rat 2 DR 10 d 26 d JV FGROBDWT WO — 30.4Mouse 2 GV 3 w NR NR JV M GRO BDWT WO — 46.4Dog 2 OR 5 w <1 yr JV NRGRO BDWT WO — 50.0Shrew 4 FD 31 d NR NR JV B GRO BDWT WO — 61.5Rat 3 GV 58 d 2 d JV BGROBDWT WO — 100Pig 2 FD 13 w 4 w JV NRGROBDWT WO — 173Rat 2 GV 29 d 2 d JV FGROBDWT WO — 200Rat 2 FD 5 w NR NR MA NRGROBDWT WO — 272Rat 2 GV 6 d 1 d JV BGROBDWT WO — 328Rat 2 DR 30 d 27 d JV MGROBDWT WO — 354Rat 2 DR 50 d 24 d JV MGROBDWT WO — 371Rat 2 GV 28 d 2 d JV MGROBDWT WO — 400Rat 4 GV 14 d 18 d JV NR GRO BDWT WO — 400

# AX7-80Table AX7-1.3.4 (cont’d). Mammalian Toxicity Data Used to Develop the Eco-SSLMammalian SpeciesNo. ofDosesRoute ofExposureExposureDurationDurationUnitsAgeAgeUnitsLifestage SexEffectTypeEffectMeasureResponseSiteNOAEL(mg/kgbw/day)LOAEL(mg/kgbw/day)Mouse 2 DR 45 d 50-100 d GE F GRO BDWT WO — 404Rat 4 FD 1 w NR NR LC F GRO BDWT WO — 442Rat 2 DR 6 w 14 w LC F GRO BDWT WO — 638Mouse 4 DR 10 w 11 w JV F GRO BDWT WO — 748Rat 2 FD 21 d NR NR LC F GRO BDWT WO — 991Rat 2 GV 18 d 2 d JV B GRO BDWT WO — 1000Rat 2 FD 2 w 0 d JV NRGRO BDWT WO — 1430Rat 4 GV 14 d 24 d JV NRGRO BDWT WO — 1600Rat 2 FD 2 w 60-80 d JV M GRO BDWT WO — 2390Rat 3 GV 14 d 16 d JV NRGRO BDWT WO — 2400Rat 2 FD 14 d 60 d JV M GRO BDWT WO — 2650AD = adult; B = both; BDWT = body weight changes; d = days; DEYO= death of young; DR = drinking water; F = female; FD = food;FERT = fertility; GMPH = general morphology;GRO = growth; GV = gavage; JV = juvenile;LC = lactation; M = male; MA = mature; mo = months; MPH = morphology; NR = not reported; ODVP = offspring development; OR = other oral;PG = prostate gland; PROG = progeny counts or numbers; PRWT = progeny weight; RBPH = reproductive behavior; REP = reproduction;RHIS = reproductive organ histology; RSEM = resorbedembryos; RSUC = reproductive success (general); RT = reproductive tissue; SM = sexually mature; SPCL = sperm cell counts; SPCV= sperm cell viability; TA = tail; TB = tibia; TE = testes;TEDG = testes degeneration; TEWT= testes weight; w = weeks; WO = whole organism; yr = years.Source: U.S. Environmental Protection Agency (2005b).

# AX7-81 Figure AX7-1.3.2. Mammalian reproduction and growth toxicity data considered in
development of the Eco-SSL.

Source: U.S. Environmental Protection Agency (2005b).



# wildlife generally would occur at doses greater than the 2 to 8 mg /kg-day reported to be toxic to

most animals in the 1986 Lead AQCD (U.S. Environmental Protection Agency, 1986a).

AX7.1.3.4 Recent Studies on the Eff ects of Lead on Decomposers

Recent studies on effects of Pb to two groups of decomposers are summarized in this

subsection. Effects on terrestrial invertebrates, such as earthwor ms and springtails, are described

first, followed by effects on microorganisms.

Effects on Invertebrates

Since the 1986 Lead AQCD, there have been several studies in which terrestrial

invertebrates were exposed to Pb in soil. Ma ny of these were reviewed during the development

of the Eco-SSLs (U.S. Environmental Protecti on Agency, 2005b). The relevant information

from the Eco-SSL document is described below.

# AX7-82 A literature search and review was conducted to identify critical papers published since

2002. Effects on earthworms and other invertebrates observed in stud ies conducted since the

1986 Lead AQCD are similar to those reported prev iously: mortality and decreased growth and

reproduction (Lock and Janssen, 2002; Davies et al., 2002; Rao et al., 2003; Bongers et al., 2004;

Nursita et al., 2005; U.S. Environmental Protection Agency, 2005b).

The literature search completed for terres trial invertebrate Eco-SSL development

identified 179 papers for detailed review, of which 13 met the minimum criteria for further

consideration (U.S. Environmen tal Protection Agency, 2005b). Most of the 18 ecotoxicological

endpoints that were further eval uated measured reproduction or survival as the ecologically

relevant endpoint. Four of these, represen ting one species under th ree different pH test

conditions were used to de velop the Eco-SSL of 1700 mg/ kg soil (Table AX7-1.3.5).

Table AX7-1.3.5. Invertebrate Toxicity Data Used to Develop the Eco-SSL

Invertebrate Species Soil pH % Organic

Matter Toxicity Parameter Pb in Soil (mg/kg dw)



# Collembola

(Folsomia candida ) 6.0 10 MATC 1 

# (reproduction) 3162

Collembola 4.5 10 MATC (reproduction) 3162

Collembola 5.0 10 MATC (reproduction) 894

Collembola 6.0 10 MATC (reproduction) 894

Geometric Mean 1682

* MATC = Maximum Acceptable Threshold Concentration, or the geometric mean of the NOEC (no-observedeffect concentration) an d LOEC (lowest-observed-effect concentration).

Source: U.S. Environmental Protection Agency (2005b).



# In a study designed to test the t oxicity of Pb to the earthworm Eisenia fetida , Davies

et al. (2002) found that the 28-day LC 50 

# (± 95% confidence intervals) for Pb in soils

contaminated with Pb(NO 3 

# ) 2 

# was 4379 ∀ 356 mg/kg. Twenty-eight day EC 50 

# values

(±95% confidence intervals) for weight change and cocoon production were 1408 ∀ 198 and

# AX7-83 971 ∀ 633 mg/kg, respectively. Significant mortalit ies were noted at concentrations of 2000

mg/kg. These data are consistent with t hose reported in the Eco-SSL document (U.S.

Environmental Protection Agency, 2005b) fo r the same species of earthworm.

Nursita et al. (2005) found no mortality a nd no adverse effects on reproduction (i.e.,

number of juveniles) of the collembolan Proisotoma minuta exposed for 42 days to 300, 750,

1500, or 3000 mg Pb/kg as Pb-nitrate in an acidic (pH = 4.88) sandy loam soil. It was noted that

the soils were allowed to equilibrate for 4 weeks after adding the Pb-nitrate before the organisms

were added. The observation of no effect at 3000 mg/kg is consistent with that of Sandifer and

Hopkin (1996). Sandifer and Hopkin (1996) de termined a NOEC (no-observed-effect

concentration) and LOEC (lowest-observed-eff ect concentration) for collembolan reproduction

of 2000 and 5000 mg/kg, respectively. (A MATC [maximum-acceptable-threshold

concentration] of 3162 mg/kg was us ed to develop the Eco-SSL).

The remaining 14 toxicity endpoints that we re not used to develop the Eco-SSL for

invertebrates are presented in Table AX7-1.3.6. None of these e ndpoints was considered eligible

for Eco-SSL derivation.

Lock and Janssen (2002) exposed the potworm Enchytraeus albidus to Pb, as Pb-nitrate.

The 21-day LC 50 

# was 4530 mg/kg, and the 42-day EC 50 

# for juvenile reproduction was

320 mg/kg. The F1 generation was then grown to maturity in the same concentration soil and

subsequently used in a reproduction test. The EC 50 

# for the F1 generation (394 mg/kg) was

similar to that of the P generation. The author s concluded that the two- generation assay did not

increase the sensitivity of the test (Lock and Janssen, 2002). None of the 18 toxicity endpoints

evaluated in detail during development of the Eco-SSLs used this species. The LC 50 

# reported for

the potworm was higher than reported for nema todes and similar to that reported for the

earthworm. The EC 50 

# for reproduction was lower than repor ted for the earthworm or collembola.

Recent work by Bongers et al. (2004) cautioned ag ainst attributing all toxicity observed in

a spiked-soil toxicity test to Pb. They found that the counterion may also contribute to the

toxicity of Pb in the springtail Folsomia candida . This may have implications on the

interpretation of the Eco-SSL data, because the t oxicity of the counterion (nitrate) was not taken

into account during Eco-SSL development. Pe rcolation (removal of the counterion) had no

statistically significant effect on Pb-chloride toxicity (LC 50 

# = 2900 mg/kg for both nonpercolated and percolated soil; EC 50 

# for reproduction = 1900 mg /kg or 2400 mg/kg for

# AX7-84 Table AX7-1.3.6. Invertebrate Toxicity Da ta Not Used to Develop the Eco-SSL

Invertebrate Species Soil pH % Organic

Matter Toxicity

Parameter Pb in Soil
(mg/kg dw)

Nematode 4 1.14 LC 50 

# 285

Nematode 4 1.14 LC 50 

# 297

Nematode 4 4.2 LC 50 

# 847

Nematode 4 4.2 LC 50 

# 1341

Nematode 6.2 1.7 LC 50 

# 1554

Nematode 5.1 3.0 LC 50 

# 891

Earthworm 6.3 10.0 EC 50 

# 1940

Earthworm 6.1 10.0 EC 50 

# 1629

Earthworm 6.0 10.0 LC 50 

# 3716

Earthworm 6.5 10.0 ILL 1.16

Nematode 4 10 LC 50 

# 1434

Nematode 4 10 NOAEC 2235

Nematode 6.1 3.4 LC 50 

# 13.9

Nematode 6.2 2.2 LC 50 

# 11.6

*NOAEC (no-observed-adverse-effect concentration); LC 50 

# (concentration lethal to 50% of test population);

EC 50 

# (effect concentration for 50% of test po pulation); ILL (incipient lethal level).

Source: U.S. Environmental Protection Agency (2005b).



# non-percolated or percolated soil, respectively). However, percolation did have a significant

effect on Pb-nitrate toxicity (LC 50 

# = 980 mg/kg or 2200 mg/kg for non- percolated or percolated

soil, respectively; EC 50 

# for reproduction = 580 mg/kg or 1700 mg/kg for non-percolated or

percolated soil, respectively). Lead nitrate was more toxic th an Pb-chloride for survival and

reproduction. However, the toxicity of Pb, from chloride or nitrate, was not significantly

different after the counterion was perc olated out of the test soil. It is noted that the soil was left

for 3 weeks to equilibrate before testing. Lock and Janssen (2002) also found that Pb-nitrate was

more toxic than Pb-chloride, and they used Pb -nitrate in their experiments because 1000 mg/kg

Pb-chloride did not produce any mortality in their range-finding tests. This difference in

# AX7-85 chloride and nitrate toxicity has not been found for earthworms (Neuhauser et al., 1985; Bongers

et al., 2004).

Rao et al. (2003) exposed the earthworm Eisenia fetida to Pb-oxide in an artificial soil

with a pH of 6 at the LC 50 

# concentration of 11 mg/kg. Exposure for 14 days resulted in a number

of effects including body fragmentat ion, protrusions, rupture of the cuticle, etc. Many of these

effects may trigger defensive mechanisms. For ex ample, fragmentation of the affected posterior

region was followed by regeneration and a new ect oderm layer was formed to cover affected

areas, both of which processes may serve to pr event soil bacteria from further affecting the

earthworm (Rao et al., 2003).

Effects on Microorganisms and Microbial Processes

Microorganisms and microbial processes were not included in the Eco-SSL development

process (see Attachment 1-2 of OSWER Di rective 92857-55 dated November 2003 in U.S.

Environmental Protection Agency [2005a]). Many reasons were given, including that it is

unlikely that site conditions would only pose unaccep table risk to microbes and not be reflected

as unacceptable risks to higher organisms; that th e significance of laborator y-derived effects data

to the ecosystem is uncertain; and that the sp atial (across millimeter distances) and temporal

(within minutes to hours) vari ation makes understanding ecologica l consequences challenging.

Microbial endpoints often vary dramatically based on moisture, temperature, oxygen, and many

non-contaminant factors. Th erefore, the recommendation arising from the Eco-SSL

development process was that risks to microbes or microbial processes not be addressed through

the chemical screening process bu t that they should be addresse d within a site-specific risk

assessment (U.S. Environmental Protection Agency, 2005b).

Few studies on the effects of Pb to microbial processes have been published since 1986.

As the direct toxicity to fungi and bacterial populations are difficult to determine and interpret,

indicators for soil commun ities are often measured as proxies for toxicity (e.g., ur ease activity in

soil). Recent studies of this nature (Doelman and Haanstra, 1986; Wilke, 1989; Haanstra and

Doelman, 1991) are summarized in this subsecti on. The Pb concentrations in these recent

studies (1000 to 5000 mg/kg) are consistent with those reported in the 1986 Lead AQCD (U.S.

Environmental Protection Agency, 1986a) as asso ciated with effects on microbial processes

(750 to 7500 mg/kg).

# AX7-86 The effects of Pb-chloride on the processes of nitrification and n itrogen mineralization

were studied in a 28-day experiment by Wilke (1 989). The authors reported that nitrification

was increased by 12 and 16% at levels of 1000 and 4000 mg/kg, respectively, and that nitrogen

mineralization was reduced by 32 and 44% at concentrations of 1000 and 4000 mg/kg,

respectively.

The effects of Pb on arylsulfatase (Haanst ra and Doelman, 1991) and urease activity

(Doelman and Haanstra, 1986) in soil were investigated. LC 50 

# s for decreases in arylsulfatase

activity were reported at Pb concentrations of 3004 and 4538 mg/kg in a silty loam soil, at pH 6

and 8, respectively. The LC 50 

# for a decrease in urease activ ity was 5060 mg Pb/kg in a sandy

loam soil.

In laboratory microcosm studies Cotrufo et al. (1995) found that decomposition of oak

( Quercus ilex ) leaf litter was reduced at elevated Pb (~20 mg Pb g ! 1 

# C) levels after 8 months

compared to controls (~2 mg Pb g ! 1 

# C). The researchers found soil respiration and amount of

soil mycelia correlated negatively with soil Pb, Zn and Cr concentration.

AX7.1.3.5 Summary

The current document expands upon and updates knowledge related to the effects of Pb

on terrestrial primary producers, consumers, and decomposers.

Primary Producers

The effects of Pb on terrestrial plants incl ude decreased photosynthe tic and transpiration

rates in addition to decreased gr owth and yield. The phytotoxicity of Pb is considered to be

relatively low, and there are few reports of phytotoxicity from Pb exposure under field

conditions. Recently, phytotoxicity data were reviewed for the development of the Eco-SSL

(U.S. Environmental Protection Agency, 2005b). Many of the toxicity data presented in the EcoSSL document (U.S. Environmental Protection Agen cy, 2005b) are lower than those discussed in

the 1986 Lead AQCD, although both documents acknowle dged that toxicity is observed over a

wide range of concentrations of Pb in soil (tens to thousands of mg/kg soil). This may be due to

many factors, such as soil conditions (e.g., pH, orga nic matter) and differences in bioavailability

of the Pb in spiked soils perhaps due to lack of equilibration of the Pb solution with the soil after

spiking. Most phytotoxicity data continue to be developed for agricultu ral plant species (i.e.,

# AX7-87 vegetable and grain crops). Few data are av ailable for trees or na tive herbaceous plants,

although two of the five toxicity endpoints used to develop the Eco-SSL were for trees and two

were for clover.

Consumers

Effects of Pb on avian and mammalian consumers include decreased survival,

reproduction, and growth as well as effects on development and behavior. There remain few

field effects data for consumers, except from sites with multiple contaminants, for which it is

difficult to attribute toxicity specifically to Pb. Avian and mammalian toxicity data recently

were reviewed for the development of Eco- SSLs (U.S. Environmental Protection Agency,

2005b). Many of the toxicity data presented in the Eco-SSL document (U.S. Environmental

Protection Agency, 2005b) are lower than those discussed in the 1986 Lead AQCD, although the

EPA (U.S. Environmental Protecti on Agency, 2005b) recognizes that toxicity is observed over a

wide range of doses (<1 to >1000 mg Pb/kg bw-day ). Most toxicity data for birds have been

derived from chicken and quail studies, and most data for mammals have been derived from

laboratory rat and mouse studies. Data derive d for other species woul d contribute to the

understanding of Pb toxicity, particularly for wi ldlife species with different gut physiologies.

In addition, data derived using environmentally realistic exposures, such as from Pbcontaminated soil and food, may be recommende d. Finally, data derived from inhalation

exposures, which evaluate endpoints such as survival, growth, and reproduction, would

contribute to understanding the implica tions of airborne releases of Pb.

Decomposers

Effects of Pb on soil invertebrates include decreased survival, growth, and reproduction.

Effects on microorganisms include changes in nitrogen mineraliza tion and enzyme activities.

Recent data on 1986 Lead toxicity to soil inverteb rates and microorganisms are consistent with

those reported in the 1986 L ead AQCD (U.S. Environmental Protection Agency, 1986a), with

toxicity generally observed at concentrations of hundreds to thousands of mg/kg soil. Studies on

microbial processes may be influenced signifi cantly by soil parameters, and the significance of

the test results is not clear.

# AX7-88 Ecological Soil Screening Levels (Eco-SSLs)

Eco-SSLs are concentrations of contaminants in soils that would result in little or no

measurable effect on ecological receptors (U.S. Environmental Protection Agency, 2005a). They

were developed following rigorous scientific protocols and were s ubjected to two rounds of peer

review. Due to conservative modeling assumptions (e.g., metal exists in most toxic form or

highly bioavailable form, high food ingestion rate, high soil inges tion rate) which are common to

screening processes, several Eco-SSLs are derived below the average background soil

concentration for a particular contaminant.

The Eco-SSLs for terrestrial plants, birds, mammals, and soil invertebrates are 120, 11,

56, and 1700 mg Pb/kg soil, respectively.



# AX7.1.4 Effects of Lead on Natural Terrestrial Ecosystems

The concept that organisms are part of larger systems that include both biotic and abiotic

components of the environment date s back to the naturalis ts of the Victorian era. However, the

breakthrough in what we now consider the ecosy stem approach to ecolo gy occurred in the 1950s

and 1960s when E.P. and H.T. Odum pioneered the quantitative analysis of ecosystems

(Odum, 1971). This approach encouraged th e calculation of energy flows into, out of, and

within explicitly defined ecosystems. The ra pid development of com puter technology aided in

the growth of ecosystem ecology by allowing the development and use of increasingly complex

models for estimating fluxes that could not be directly measured.

It was not long before the qua ntitative analysis of ecosystems was extended to examine

the flows of nutrients and other chemical comp ounds. In temperate terrestrial systems, the

watershed was identified as a convenient and informative experimental unit (Bormann and

Likens, 1967). A major conceptual breakthrough in the watershed approach was that drainage

water chemistry could be used as an indicator of the “health” of the eco system. In a system

limited by nitrogen, for example, elevated concentrations of NO 3 ! 

# in drainage waters indicate that

the ecosystem is no longer making optimal use of available nutrients.

The ecosystem approach can also be used effectively in the st udy of trace element

biogeochemistry. Input-output budg ets can be used to determine whether an ecosystem is a net

source or sink of a trace element. Changes to th e input-output balance over time can be used to

assess the effects of natural or experimental changes in deposition, land use, climate, or other

# AX7-89 factors. In addition, examinati on of fluxes within the ecosystem (in plant uptake, soil solutions,

etc.) can be used to understand the processes that are most influen tial in determining the fate and

transport of the trace element.

Many published ecosystem studies include data for 1 to 3 years, the typical duration of

research grant funding or doctoral dissertation research. While these studies enrich our

understanding of terrestrial ecosystems, the most valuable studies are those that are maintained

over many years. Natural variations in climate, pests, animal migrations, and other factors can

make inferences from short-term studies mi sleading (Likens, 1989). To nurture long-term

research, the National Science Foundation s upports a network of Long-Term Ecological

Research (LTER) sites that re present various biomes.

This section describes terrestrial ecosystem research on Pb, focusing on work done since

the 1986 Lead AQCD (U.S. Environmental Prot ection Agency, 1986a) and highlighting key

long-term studies. Unfortunately, there are few studies that featur e long-term data on trace metal

behavior at multiple levels of or ganization. Therefore, this exam ination of the effects of Pb on

terrestrial ecosystems combines insights from long- and short-term investigations as well as

studies at scales including whole ecosystems, communities, populations, and individual species.

AX7.1.4.1 Effects of Terrestrial Ecos ystem Stresses on Lead Cycling

Terrestrial ecosystems may respond to stressors in a variety of ways, including reductions

in the vigor and/or growth of vegetation, reduc tions in biodiversity, and effects on microbial

processes. Each of these effects may lead to the “leakage” of nutrients, especially nitrogen, in

drainage waters. The reduced vi gor or growth of vegetation resu lts in a lower uptake of nitrogen

and other nutrients from soils. Reduced biodi versity accompanied by lower total net primary

productivity for the ecosystem would also result in a lower nutrient uptake. Effects of stress in

microbial populations are less obv ious. If the stress reduces mi crobial activity rates, then

nutrients bound in soil organic matter (e.g., organic nitrogen compounds) will likely be

mineralized at a lower rate and re tained in the system. On the other hand, disturbances such as

clear-cutting, ice-storm damage, and soil freezing can result in substantial nutrient losses from

soils (Bormann et al., 1968; Li kens et al., 1969; Mitchell et al., 1996; Groffman et al., 2001;

Houlton et al., 2003).

# AX7-90 Since the movement and fate of Pb in terrest rial ecosystems is strongly related to the

organic matter cycle (Section AX7.1.2), stressors that could lead to disrupti on or alteration of the

soil organic matter pool are of part icular concern in assessing effects of ecosystem stress on Pb

cycling. By binding soluble Pb, so il organic matter acts as a ba rrier to the release of Pb to

drainage waters (Wang et al., 1995; Kaste et al., 2003; Watmough and Hutchinson, 2004). As a

result, concentrations of Pb in soil solutions and drainage waters tend to be low (Driscoll et al.,

1988; Wang et al., 1995; Bacon and Bain, 1995; Johnson et al., 1995a). Through decomposition

and leaching, soluble organic matter is released to solution, and with it, some Pb is also

mobilized. Wang and Benoit (1996) found that essentially all of the Pb in soil solutions in a

hardwood forest in New Hampshire was bound to di ssolve organic matter (DOM). This release

of soluble Pb does not typically result in elevated surface wate r Pb concentrations, because

(1) organic matter has a relatively long residence time in most temperate soils (Gosz et al., 1976;

Schlesinger, 1997), so only a small fraction of th e organic matter pool is dissolved at any time;

(2) DOM-Pb complexes solubilized in upper soil hor izons may be precipitated or adsorbed lower

in the soil profile; (3) the DOM to which Pb is bound may be utilized by microbes, allowing the

associated Pb to bind anew to soil organic matter. Together, these factors tend to moderate the

release of Pb to surface waters in temperate terrestrial ecosyst ems. However, stressors or

disturbances that result in increased release of DOM from soils could result in the unanticipated

release of Pb to groundwater and/or surface waters.

Acidification

The effect of acidification on ecosystem cycling of Pb is difficult to predict. Like most

metals, the solubility of Pb increases as pH decreases (Stumm and Morgan, 1995), suggesting

that enhanced mobility of Pb should be found in ecosystems under acidification stress. However,

Pb is also strongly bound to organic matter in soil s and sediments. Reductions in pH may cause

a decrease in the solubility of DOM, due to the protonation of carboxylic functional groups

(Tipping and Woof, 1990). Because of the importance of Pb complexation with organic matter,

lower DOM concentrations in soil solution result ing from acidification may offset the increased

solubility of Pb and hence decrease the mobility of the organically bound metal.

In a study of grassland and forest soils at th e Rothamsted Experiment Station in England,

long-term (i.e., >100 years) soil acidification signif icantly increased the mob ility of Pb in the soil

# AX7-91 (Blake and Goulding, 2002). However, the increased mobility was only observed in very acid

soils, those with pH of <4.5. The fraction of exchangeable Pb (extracted with 0.1 M CaCl 2 

# )

increased from about 3% to 15% of the total Pb in the most acidified soils. Similarly, the

fraction of organically bound Pb increased from about 2% of total Pb in neutral soils to 12% of

total Pb in the most acidified soils. Simila rly, Nouri and Reddy (1995) obs erved higher levels of

diethylenetriaminepentaacetic-acid-[DTPA]-extractab le Pb in soils in a loblolly pine forest

treated with simulated acid rain, but only in the mo st acidic treatment, with simulated rain with a

pH of 3.5.

Although acidification may increas e the mobility of Pb in some soils, it is not clear that

this Pb is actually moving through or out of the soil profile. In an examination of running waters

in Sweden, Johansson et al. (1995) found no relationship between acidification and Pb

concentrations in drainage wate rs and concluded that Pb conc entrations were governed by the

DOM concentration, which masked any associ ation with acidification. In an in situ lysimeter

study, Bergkvist (1986) measured lower concentr ations of Pb in soil solutions draining

experimentally acidified plots th an in unacidified plots. In a laboratory study using large soil

columns, Merino and García-Rodeja (1997) observed no effect of experimental acidification on

the release of Pb to soil solution. Thus, while ac idification may increase th e potential mobility of

Pb in soils, as indicated by increases in labile soil fractions such as exchangeable and DTPAextractable Pb, the actual movement of Pb in the soil is limited by DOM solubilization and

transport. It is worth noting that in all of these studies, significant effects of acidification were

observed for other trace metals (Bergkvist, 1986 ; Johansson et al., 1995; Merino and GarcíaRodeja, 1997).

Acidification may enhance Pb export to draina ge water in very sandy soils, soils with

limited ability to retain organic matter. Studies in the McDonald’s Branch watershed in the

New Jersey pine barrens, where soil texture is similar to beach sands , suggested little Pb

retention in the mineral soil (Swanson and Johns on, 1980; Turner et al., 1985). If acidification

results in the mobilization of Pb and organic ma tter into these mineral soils, then increased

streamwater Pb concentrations would likely follow.

# AX7-92 Land Use and Industry

Changes in land use also represent potentia lly significant changes in the cycling of

organic matter in terrestrial ecosystems. Conversion of pasture and croplands to woodlands

changes the nature and quantity of organic matter i nputs to the soil. In te mperate climates, forest

ecosystems tend to accumulate organic matter in an O horizon on the forest floor, whereas

organic matter in grasslands and agricultural fields is concentrated in an A horizon at the soil

surface. Andersen et al. (2002) compared the tr ace metal concentrations in arable fields in

Denmark to nearby sites that had been converted to forest land. After 34 years of afforestation,

the soils showed no significant difference in Pb concentration or fracti onation, despite significant

acidification of the soils. Afforestation ha d no effect on the soil carbon concentration,

suggesting that land use change may have little effect on Pb cycling unless soil carbon pools are

affected.

Similarly, the introduction of industrial activity may have consequences for organic

matter cycling, and subsequently, Pb mobilization. In a rare long-term study of polluted soils,

Egli et al. (1999) studied the changes in trace metal concentrations in forest soils at a site in

western Switzerland between 1969 and 1993. The site is 3 to 6 km downwind from an aluminum

industrial plant that operated between the 1950s and 1991. In the 24-year period of study, the

site experienced significant d eclines in organic carbon in su rface (0 to 5 cm depth) and

subsurface (30 to 35 cm) soils. In the 30 to 35 cm layer, the organic carbon concentration

declined by more than 75%. Extractable Pb (using an ammonium acetat e and EDTA mixture)

declined by 35% in the same layer. The authors suggested that the Pb lost from the soil had been

organically bound. While this study indicates that loss of soil carbon can induce the mobilization

and loss of Pb from terrestrial ecosystems, it is also worth noting that the decline in soil Pb was

considerably smaller than the decline in organi c carbon. This suggests that Pb mobilized during

organic matter decomposition can resorb to rema ining organic matter or perhaps to alternate

binding sites (e.g., Fe and Mn oxides).

The effects of industries that emit Pb to the atmosphere are discussed in Sections

AX7.1.5.2 and AX7.1.5.3 below.

Forest harvesting represents a severe disrupt ion of the organic matter cycle in forest

ecosystems. Litter inputs are severely reduced for several years after cutting (e.g., Hughes and

Fahey, 1994). The removal of the forest canopy resu lts in reduced interception of precipitation,

# AX7-93 and, therefore, increased water flux to the soil surface. Also, until a new canopy closes, the soil

surface is exposed to increased solar radiation and higher temper atures. Together, the higher

moisture and temperature in surface soils te nd to increase the rate of organic matter

decomposition. Several studies have estimated decreases of up to 40% in the organic matter

content of forest floor soils af ter clear-cutting (Covington, 1981; Federer, 1984; Johnson et al.,

1995b). This loss of organic matter from the fore st floor could result in the mobilization of

organically complexed Pb. However, observations from clear-cut sites in the United States and

Europe indicate that forest harvesting causes little or no mobilization of Pb from forest soils.

At the Hubbard Brook Experimental Forest in New Hampshire, whole-tree harvesting, the

most intensive form of clear-cutting, resulted in ve ry small increases in Pb concentrations in soil

solutions draining the Oa soil hori zon despite substantia l reductions in the organic matter mass of

that horizon (Fuller et al., 1988; Johnson et al., 1995b). These in creases were associated with

similarly small increases in dissolved organi c carbon (DOC) concentratio ns in the Oa horizon

soil water. Output of Pb from the watershed stream was unaffected by clear-cutting. Similarly,

Berthelsen and Steinnes (1995) observed small d ecreases in the Pb content of the Oa horizon

(“H” in the European system of soil classificatio n) in clear-cut sites in Norway, compared to

uncut reference sites. This mobilization of Pb from the Oa horizon was accompanied by an

increase in the Pb content of the upper minera l soil horizons. The Pb decline in the Oa horizon

was accompanied by a decrease in the organic matter content, leading the au thors to attribute the

Pb dynamics to leaching with DOM. In a st udy conducted in Wales, Durand et al. (1994)

observed lower Pb outputs from a stream draining a clear-cut watershed than from where the

stream drained the upper reaches of the wa tershed, which were uncut. The DOC and H + 

# outputs

were also lower in the clear-cut area. These pa tterns persisted in all 5 years of the study.

Forest harvesting is a severe form of ecosyst em disturbance, and, t hus, it is somewhat

surprising that studies of clear-cutting have show n little or no effect on Pb mobility or loss from

forest ecosystems. Perhaps the strong complexa tion behavior of Pb with natural organic matter

results in the retention of Pb in forest soils. Ev en in cases where Pb is mobilized in forest floor

soils (Fuller et al., 1988; Berthels en and Steinnes, 1995), there is no evidence of loss of Pb from

the ecosystem, indicating that mineral soils are effi cient in capturing and re taining any Pb that is

mobilized in the forest floor. Therefore, the princi pal risk associated with forest harvesting is the

loss of Pb in particulate form to drainage wa ters through erosion. In some relatively remote

# AX7-94 lakes in the United Kingdom th e distribution of sediment-bound trace elements (including Pb)

have been affected by forestry activities a nd catchment erosion (Yang and Rose, 2005). Yang

and Rose (2005) believe that more contaminated soil in-wash could increase sediment heavy

metal concentrations while less contaminated so il in-wash could dilute sediment heavy metal

levels.

Climate Change

Atmospheric Pb is not likely to contribute si gnificantly to global climate change. Lead

compounds have relatively short residence times in the atmosphere, making it unlikely that they

will reach the stratosphere. Also, Pb compounds are not known to absorb infrared radiation and,

therefore, are unlikely to cont ribute to stratospheric ozone de pletion or global warming.

Climate change does, however, represent a disturbance to terrestrial ecosystems.

Unfortunately, the potential linka ges between climate-related stre ss and Pb cycling are poorly

understood. As in the previous examples, effects related to alterations in organic matter cycling

may influence Pb migration. For example, an in crease in temperature leading to increased rates

of organic matter decomposition could lead to te mporary increases in DOM concentrations and

smaller steady-state pools of soil organic matter. Either of these factors could result in increased

concentrations of Pb in waters draining terrestrial ecosystems.

Climate change may also affect the fluctuati ons of temperature and/ or precipitation in

terrestrial ecosystems. For exampl e, there is some evidence for recent increases in the frequency

of soil freezing events in the nor theastern United States (Mitch ell et al., 1996). Soil freezing

occurs when soils have little or no snow cover to insulate them from cold temperatures and

results in an increased release of nitrate and DOC from the O hor izons of forest soils (Mitchell

et al., 1996; Fitzhugh et al., 2001). Increased DOC losses from O horizons subjected to freezing

may also increase Pb mobilization.

Increased fluctuations in precipitation may induce more frequent flooding, with

potentially significant consequences for Pb c ontamination of floodplain ecosystems. Soils

collected from the floodplain of the Elbe River, in Germany, contained elevated concentrations

of Pb and other trace metals (Kr η ger and Grongroft, 2003). Tissues of plants from floodplain

sites did not, however, contain higher Pb concentr ations than control si tes. More frequent

# AX7-95 or more severe flooding would lik ely result in increased inputs of Pb and other metals to

floodplain soils.

AX7.1.4.2 Effects of Lead Exposure on Natural Ecosystem Structure and Function

The effects of Pb exposure on natural ecosy stems are confounded by the fact that Pb

exposure cannot be decoupled fr om other factors that may also affect the ecosystem under

consideration. Principal among these factors are other trace metals and acidic deposition.

Emissions of Pb from smelting and other indus trial activities are acco mpanied by other trace

metals (e.g., Zn, Cu, and Cd) and sulfur dioxide (SO 2 

# ) that may cause toxic effects independently

or in concert with Pb. Reductions in the use of alkyl-Pb additives in ga soline have resulted in

significant decreases in Pb depos ition to natural ecosystems in the northeastern United States

(Johnson et al., 1995a). However, the period in which Pb deposition has declined (ca. 1975 to

the present) has also seen signi ficant reductions in the acidity (i .e., increased pH) of precipitation

in the region (Likens et al., 1996; Driscoll et al., 1998). Theref ore, changes in ecosystem Pb

fluxes may be the result of reduced Pb inputs and/or reduced acidity.

Experimental manipulation studies do not su ffer from these confounding effects, because

Pb can be added in specific amounts, with or without other co mpounds. Unfortunately,

ecosystem-level manipulations involving Pb additi ons have not been undertaken. Therefore, we

must use observations from field st udies of Pb behavior in sites exposed to various forms of Pb

pollution to assess the effects of Pb on terrestria l ecosystems. This section includes a discussion

of effects of Pb in the structure and function of terrestrial ecosystems. Effects on energy flows

(food chain effects) and biogeochemical cy cling are discussed in Section AX7.1.5.3.

Sites Affected by Nearby Point Sources of Lead

Natural terrestrial ecosystems near smelters , mines, and other industrial plants have

exhibited a variety of effects re lated to ecosystem structure and function. These effects include

decreases in species diversity, changes in floral and faunal community composition, and

decreasing vigor of terrestrial vegetation.

All of these effects were observed in eco systems surrounding the Anaconda smelter in

southwestern Montana, which operated between 1884 and 1980 (Galbraith et al., 1995). Soils in

affected areas around the Anaconda smelter were en riched in Pb, arsenic, copper, cadmium, and

# AX7-96 zinc; had very low pH; and were determined to be phytotoxic to native vegetation (Kapustka

et al., 1995). The elevated soil arsenic and metal concentrations occurred despite significantly

lower organic matter concentrations in affected so ils relative to reference sites (Galbraith et al.,

1995). Line-transect measurements indicated that affected sites had an average of 6.9 species per

10-m of transect, compared to 20.3 species per 10- m in the reference areas. More than 60% of

the reference sites supported coniferous (58 %) or deciduous (3%) forest communities, whereas

less than 1% of the affected si tes retained functioning forest st ands. Abundant dead timber and

stumps confirmed that the affected sites were once as forested as the reference sites. Affected

grassland sites were also less diverse and had higher abundances of invasive species than

reference grasslands. More than 50% of the aff ected sites were classified as bare ground. The

occurrence of bare ground was si gnificantly correlated with the phytotoxicity scores derived by

Kapustka et al. (1995), indicating a link between phytotoxicity and th e loss of vegetation in the

affected area.

Because of the plant community changes near the Anaconda smelter, the vertical diversity

of habitats in the affected ecosystems decrease d, with only shrubs and soil remaining as viable

habitats. Galbraith et al. (1995) also used the Bureau of Land Management’s habitat evaluation

procedure (HEP) to estimate habitat suitability indices (HSI) for two indicator species, marten

( Martes americana ) and elk ( Cervus elaphus ). The HSI value ranges from 0 (poor habitat) to

1 (ideal habitat). In sites affected by the Anac onda smelter, HSI values for marten averaged 0.0,

compared to 0.5 to 0.8 for the reference sites. For elk, affected sites had an average HSI of 0.10,

compared to 0.31 at reference sites.

Similar observations were made in the ar ea surrounding Palmerton, Pennsylvania, where

two zinc smelters operated between 1898 and 1980. Soils in the area were enriched in Cd, Zn,

Pb, and Cu, with concentrations decreasing with distance from the smelter sites (Beyer et al.,

1985; Storm et al., 1994). Smelting was determined to be the principal source of Pb in soils in

residential and undeveloped areas around Palmert on (Ketterer et al., 2001), which lies on the

north side of a gap in Blue Mountain, a ri dge running roughly east-w est in east-central

Pennsylvania. Much of the north-facing side of Blue Mountain within 3 km of the town is bare

ground or sparsely vegetated, whereas the surr ounding natural landscape is predominantly oak

forest (Sopper, 1989; Storm et al., 1994). Biodivers ity in affected areas is considerably lower

than at reference sites, a pattern attributed to emissions from th e smelters (Beyer et al., 1985;

# AX7-97 Sopper, 1989). The history is complicated, how ever, by the land use history of the area.

Logging and fire in the early 20th century may al so have played a role in the changes in the

terrestrial ecosystems (Jordan, 1975). Extens ive logging occurred after the smelters began

operation, suggesting that some of the logging may have been salvage logging in affected areas.

Regardless, the smelter emissions appear to have inhibited the regrowth of ecosystems compared

to those in nearby unaffected areas. As in Anaconda, MT, the changes in the structure and

function of the Palmerton ecosystem changed its suitability as a habitat for fauna that would

normally inhabit the area. Storm et al. (1994) did not find amphibians or common invertebrates

in two study sites nearest to the smelters. In the larger study area, they documented elevated

concentrations of Pb, Cd, Cu, and Zn in tissues of species ranging in size from red-backed

salamanders ( Pletheron cenereus ) to white-tailed deer ( Odocoilius virginianus ).

Metal pollution around a Pb-Zn smelter near Bristol, England has not resulted in the loss

of oak woodlands within 3 km of the smelter, despite significant accumulation of Pb, Cd, Cu,

and Zn in soils and vegetation (Martin a nd Bullock, 1994). However, the high metal

concentrations have favored the growth of metal-tolerant species in the woodland.

The effects of Pb and other chemical emissi ons on terrestrial ecosystems near smelters

and other industrial sites decrea se downwind from the source. Several studies using the soil

burden as an indicator have shown that much of the contamination occurs within a radius of

20 to 50 km around the emission source (Miller and McFee, 1983; Martin and Bullock, 1994;

Galbraith et al., 1995; Spurge on and Hopkin, 1996a; see also S ection AX7.1.2). For example,

the concentration of Pb in fore st litter declined downwind from a Pb-Zn smelter near Bristol,

UK, from 2330 to 3050 ppm in a stand 2.9 km from the smelter to 45 to 110 ppm in a stand

23 km from the smelter (Martin and Bullock, 1994). Thus, while sites near point sources of Pb

may experience profound effects on ecosystem struct ure and function, the extent of those effects

is limited spatially. Elevated metal concentrations around smelte rs have been found to persist

despite significant reduct ions in emissions (Hrsak et al., 2000). Most terrestrial ecosystems are

far enough from point sources that long-range Pb transport is the primary mechanism for Pb

inputs.

# AX7-98 Sites Affected by Long-Range Lead Transport

Because the effects of anthropogenic Pb emi ssions tend to be restricted in geographic

extent, most natural terrestrial ecosystems in the U.S. sites have Pb burdens derived primarily

from long-range atmospheric trans port. Pollutant Pb represents a large fraction of the Pb in

many of these ecosystems. In particular, many of these sites have accumulated large amounts of

Pb in soils. For example, at the Hubbard Br ook Experimental Forest in New Hampshire, the

amount of Pb in the forest floor was estim ated to have increased from about 1.35 kg ha ! 1 

# in 1926

(before the introduction of alkyl-Pb additives in gasoline) to 10.5 kg ha ! 1 

# in 1977 (Johnson et al.,

1995a). They also estimated the atmospheri c Pb deposition from 1926 to 1987 to be 8.7 kg ha ! 1



# ,

an amount that could account for nearly all of the incr ease in Pb in the fo rest floor during the

period. The input of precipitation Pb to th e Hubbard Brook ecosystem in the six decades

spanning 1926 to 1987 was more than half of the total Pb estimated to have been released by

mineral weathering in the entire 12,000- to 14,000-year post-glacial period (14.1 kg ha ! 1 

# :

[Johnson et al., 2004]). Other studies employi ng Pb budgets (Miller and Friedland, 1994;

Watmough et al., 2004), and Pb isotopes (Baco n et al., 1995, 1996; Watmough et al., 1998;

Bindler et al., 1999; Hansmann and Köppel, 2000; Kaste et al., 2003), have also shown that

pollutant Pb, primarily from gasoline combustion, re presents a quantitativel y significant fraction

of labile Pb in temperate soils, especially in the upper, orga nic-rich horizons.

Despite years of elevated atmospheric Pb inputs and elevated concentrations in soils, there

is little evidence that sites affected primar ily by long-range Pb transport have experienced

significant effects on ecosystem structure or f unction. Low concentrations of Pb in soil

solutions, the result of strong complexation of Pb by soil organic matter, may explain why few

ecological effects have been observed. At Hubba rd Brook, for example, the concentration of Pb

in soil solutions draining the Oa horizon is < 0.1 μM and is even lower in solutions draining

mineral-soil horizons (Driscoll et al., 1988; Wang et al., 1995). Friedland and Johnson (1985)

measured similar concentrations in soil solution s collected from deciduous and spruce-fir stands

on Camel’s Hump Mountain in Vermont. In an undeveloped, forested watershed in Maryland,

Scudlark et al. (2005) found that atmospheric input of some elements (Al, Cd, Ni, Zn) is

effectively transmitted through the watershed, wher eas other elements (Pb, As, Se, Fe, Cr, Cu)

are strongly sequestered, in the respective order noted.

# AX7-99 In ecosystems where Pb concentrations in so il solutions are low, toxicity levels for

vegetation are not likely to be reached regardless of the soil Pb concentration. Furthermore,

mycorrhizal infection of tree root s appears to reduce the translocat ion of Pb from roots to shoots

(Marschner et al., 1996; Jentschke et al., 1998). In a study of mycorrhizal and non-mycorrhizal

Norway spruce ( Picea abies (L.) Karst.), mycorrhizal infecti on of roots was not affected by Pb

dose. Some, but not all, species of myco rrhizae showed reductions in the amount of

extrametrical mycelium with Pb exposure but only at solution concentrations of 5 μM, a level at

least 50 times greater than typical concentrations in forest soils. In a related study, the growth

rate of mycorrhizal fungi was unaffected at so lution Pb concentrations of 1 and 10 μM, but

decreased at 500 μM (Marschner et al., 1999).

Low soil solution Pb concentrations and the influence of mycorrhizal symbionts also

result in low uptake of Pb by terrestrial vegetati on. The net flux of Pb into vegetation in the

northern hardwood forest at Hubbard Brook in the 1980s was estimated as only 1 g ha ! 1 

# year ! 1



# (Johnson et al., 1995a), representing 3% of the precipitation input. Klaminder et al. (2005) also

measured a Pb uptake of 1 g ha ! 1 

# year ! 1 

# in a spruce-pine forest in northern Sweden. Despite plant

uptake fluxes being very low, they are sensitive to differences and changes in Pb deposition.

Berthelsen et al. (1995) observed decreases in the Pb content of stem, twig, leaf, and needle

tissues of a variety of tree species in No rway between 1982 and 1992, when atmospheric Pb

deposition declined by approximately 70%. Th ey also observed significantly lower Pb

concentrations in tree tissues collected in nor thern Norway versus southern Norway, where

atmospheric Pb deposition is greater.

Even at subtoxic concentrations, Pb and othe r metals may influence species diversity in

terrestrial ecosystems. However, little work ha s been done on the effect of low-level metal

concentrations on species diversity. In one study, plant species diversity was positively

correlated to the concentration of available Pb in natural and artificial urban meadows in Britain

(McCrea et al., 2004). The aut hors hypothesized that Pb may inhibit phosphorous uptake by

dominant species, allowing less abundant (but more Pb-tol erant) ones to succeed.

AX7.1.4.3 Effects of Lead on Energy Flows and Biogeochemical Cycling

In terrestrial ecosystems, energy flow is clos ely linked to the carbon cycle. The principal

input of energy to terrestrial ecosyste ms is through photosynthesis, in which CO 2 

# is converted to

# AX7-100 biomass carbon. Because of this link between photosynthesis and energy flow, any effect that Pb

has on the structure and function of terrestrial ecosystems (as discu ssed in Section AX7.1.5.3.)

influences the flow of energy into the ecosystem . This section focuses on how Pb influences

energy transfer within terrestrial ecosystems, which begin with the de composition of litter and

other detrital material by soil bacteria and fungi, and cascade th rough the various components of

the detrital food web. Because the mobility of Pb in soils is closely tied to organic matter

cycling, decomposition processes ar e central to the biogeochemical cycle of Pb. This section

concludes with a discussion of how biogeochemical cycling of Pb has changed in response to the

changing Pb inputs to terrestrial ecosystems.

Effects of Lead on Detrital Energy Flows

Lead can have a significant effect on energy fl ows in terrestrial ecosyst ems. At some sites

severely affected by metal pollu tion, death of vegetation can occu r, dramatically reducing the

input of carbon to the ecosystem (Jordan, 1975; Galbraith et al., 1995). Subsequently, wind and

erosion may remove litter and humus, leaving bare mineral soil, a nearly sterile environment in

which very little energy transfer can take place (Little and Martin, 1972; Ga lbraith et al., 1995).

At Pb-affected sites that can re tain a functioning forest stand, the rate of decomposition of

litter may be reduced, resulting in greater accumu lation of litter on the forest floor than in

unpolluted stands. Numerous investigators ha ve documented significan t declines in litter

decomposition rates (Cotrufo et al., 1995; Johns on and Hale, 2004) and/or the rate of carbon

respiration (Laskowski et al., 1994; Cotrufo et al ., 1995; Saviozzi et al., 1997; Niklínska et al.,

1998; Palmborg et al., 1998; Aka and Darici, 2004) in acid- and metal-contam inated soils or soils

treated with Pb. The resulting accumulation of organic matter on the soil surface can be

dramatic. For example, an oak woodland 3 km fr om a smelter in Bristo l, England had a litter

layer mass 10 times greater than the mass in a si milar stand 23 km from the smelter (Martin and

Bullock, 1994).

Reduced decomposition rates in polluted ecosystem s are the result of the inhibition of soil

bacteria and fungi and its effects on microbial community structure (Bååth, 1989). Kuperman

and Carreiro (1997) observed 60% lower substrat e-induced respiration in heavily polluted

grassland soils near th e U.S. Army’s Aberdeen Proving Grou nd in Maryland. This decline in

carbon respiration was associated with 81% lo wer bacterial biomass and 93% lower fungal

# AX7-101 biomass. Similar declines in the activities of carbon-, nitrogen-, and phosphorus-acquiring

enzymes were also observed. Such dramatic effects have only been observed in highly

contaminated ecosystems. In a less contaminated grassland site near a Pb factory in Germany,

Chander et al. (2001) observed a lower ratio of microbial biomass carbon to soil organic carbon

in polluted soils. The ratio of basal respiration to microbial biomass (the “metabolic quotient,”

qCO 2 

# ) declined with increasing metal concentr ation, though this observation depended on the

procedure for measuring microbial biomass (subs trate-induced respiration versus fumigationextraction). The combined effect of lower micr obial biomass per unit soil carbon and similar or

lower qCO 2 

# on polluted sites indicates that the ability of soil microorganisms to process carbon

inputs is compromised by metal pollution.

The type of ecosystem also plays a role in de termining the effects of Pb and other metals

on the microbial processing of litter. Forest so ils in temperate zones accumulate organic matter

at the soil surface to a greater degree than in gr asslands. This organic- rich O horizon can support

a large microbial biomass; but it is also an effect ive trap for Pb inputs, because of the association

between Pb and soil organic matter. At highly c ontaminated forest sites, microbial biomass and

enzyme activities may be depressed (Fritze et al., 1989; Bååth et al., 1991), causing slower

decomposition of the litter.

In addition to effects on decomposition and carbon transformations, Pb and other trace

metals can also influence key nitrogen cycling pr ocesses. Studies in th e 1970s demonstrated that

Pb and other metals inhibit the mineralizati on of nitrogen from soil organic matter and

nitrification (Liang and Tabatabai, 1977, 1978), resulting in lower nitr ogen availability to plants.

More recent research has documented significant inhi bitory effects of Pb and other metals on the

activities of several enzymes believed to be crucial to nitrogen mineralization in soils (Senwo

and Tabatabai, 1999; Acosta-Martinez and Tabataba i, 2000; Ekenler and Tabatabai, 2002). This

suggests that the inhibitory effect of Pb and other metals is broa d-based, and not specific to any

particular metabolic pathway. In reducing enviro nments, the rate of denitrification is also

depressed by trace metals. Fu and Tabatabai (1989) found that 2.5 μmol g ! 1 

# of Pb (ca.

500 mg/kg ! 1 

# ) was sufficient to cause 0, 27, and 52% decr eases in nitrogen reductase activity in

three different soils.

Metal pollution can also affect soil invertebrate populations. Martin and Bullock (1994)

observed lower abundances of a variety of woodlice, millipedes, spiders, insects, and earthworms

# AX7-102 in an oak woodland site 3 km from a Pb-Zn smelte r in Bristol, England, co mpared to a reference

site 23 km from the smelter. The differences were most dramatic when expressed per unit mass

of litter. Several species that were abundant in the reference site were not found in the

contaminated woodland. For exampl e, the abundance of the woodlice Trichoniscus pusillus

was 151 individuals per m 2 

# in the reference woodland, but none were found in the contaminated

soils. This was also true of 2 of the 3 m illipede species, and 4 of the 5 earthworm species

studied. At six sites within 1 km from the sm elters, no earthworms were present at all (Spurgeon

and Hopkin, 1996a). Contamination at this site has apparently reduced both the population and

biodiversity of the soil in vertebrate community.

The effect of metal pollution on soil invertebrates may be a threshold-type response. In a

study conducted in woodlands near two zinc smelters in Noyelles-Godault, in northern France,

soils at the most polluted site were devoid of mites and millipedes, while the remaining sites had

diversity measures similar to cont rol sites (Grelle et al., 2000).

While Pb pollution affects the population and di versity of soil fauna, there is little

evidence of significant bioaccumulation of Pb in the soil food web (see also Section AX7.1.3).

In the Bristol, England study, Pb concentratio ns in earthworms were lower than soil Pb

concentrations and much lower than litter Pb c oncentrations (Martin and Bullock, 1994). Litterdwelling mites had Pb concentrations that were 10% of the average litte r concentration. The

predator centipedes Lithobius forficatus and L. variegatus had mean Pb concentrations of

18.6 and 44.0 mg kg ! 1 

# , respectively, two orders of magnitude lower than the Pb concentration of

litter (2193 mg kg ! 1 

# ) and lower than the concentrations of their known prey species. In a study

conducted in a Norway spruce forest affected primarily by automobile exhaust from a nearby

highway, earthworms had Pb concentrations simila r to the soil (Roth, 1993) . Almost all of the

litter decomposers, however, had Pb concentrations that were less than 20% of the litter. All but

3 of the zoophagous arthropods had Pb concentrations that were less than 40% of their prey; the

remaining 3 had Pb concentrations similar to thei r prey. Because of the absence of significant

bioaccumulation in the soil food web, predator speci es will be affected by Pb pollution primarily

through effects on the abundance of their prey (Spurgeon and Hopkin, 1996b).

Taken as a whole, ecosystem-level studies of the soil food web indicate that Pb can affect

energy flows in terrestrial ecosystems through two principal mechanisms. In the most severely

polluted sites, the death of primary producers di rectly decreases the flow of energy into the

# AX7-103 ecosystems. More commonly, the accumulation of toxic levels of Pb or other metals in litter and

soil decreases the rate of litter decomposition th rough decreases in microbial biomass and/or

respiration. These reductions can subsequently a ffect higher trophic levels that depend on these

organisms. It is important to note that sites that have exhibited signi ficant disruption to energy

flows and the terrestrial food web are sites that have experienced severe metal contamination and

adverse effects from SO 2 

# from smelters or other metals-related activities.

Lead Dynamics in Terrestrial Ecosystems

Lead inputs to terrestrial ecosystems in the Unite d States have declined dramatically in the

past 30 years, primarily because of the almost complete elimination of alkyl-Pb additives in

gasoline in North America. Also, Pb emissions from smelters have declined as older plants have

been shut down or fitted with improved emissi ons controls. Unfortunately, there are few longterm data sets of precipitation inputs to te rrestrial ecosystems. At the Hubbard Brook

Experimental Forest, in New Hampshire, Pb in put in bulk deposition declined by more than 97%

between 1976 and 1989 (Johnson et al., 1995a). Studies of freshwater sediments also indicate a

dramatic decline in Pb inputs since the mid- 1970s (Graney et al., 1995; Johnson et al., 1995a;

Farmer et al., 1997; Br ännvall et al., 2001a,b).

Reported concentrations of Pb in waters dr aining natural terrestri al ecosystems have

always been low (Wang et al., 1995; Bacon and Bain, 1995; Johnson et al., 1995a; Vinogradoff

et al., 2005), genera lly less than 1 ng L ! 1 

# , even at moderately pollu ted sites (Laskowski et al.,

1995). Consequently, most terrestrial ecosystems in North America and Europe remain sinks for

Pb despite reductions in atmospheric Pb deposi tion of more than 95%. At Hubbard Brook, for

example, the input of Pb in bulk precipitation declined from 325 g ha ! 1 

# year ! 1 

# between 1975 and

1977 compared to 29 g ha ! 1 

# year ! 1 

# between 1985 and 1987 (Johnson et al., 1995a). During the

same period, the output of Pb in stream water declined from 6 g ha ! 1 

# year ! 1 

# to 4 g ha ! 1 

# year ! 1



# .
Thus, despite the decline in Pb input, 85% of the incoming Pb was still reta ined in the terrestrial

ecosystem in the later time period. Similar obser vations have been made in Europe, where the

use of leaded gasoline has also declined in th e last few decades. At the Glensaugh Research

Station in Scotland, the input of Pb to the forest ecosystem was estimated as 42.6 g ha ! 1 

# year ! 1



# between 2001 and 2003, about six time s the stream export of 7.2 g ha ! 1 

# year ! 1 

# (Vinogradoff et al.,

2005). Similarly, Huang and Matzner (2004) reported a throughfall flux of 16.5 g ha ! 1 

# year ! 1 

# at

# AX7-104 the forested Lehstenbach catchment in Bavaria, about six times the efflux in runoff of 2.82 g ha ! 1



# year ! 1



# .
Lead pollution has resulted in the accumulation of large Pb burdens in terrestrial

ecosystems (see also Section AX7.1.2). Despite reduc tions in emissions, this accumulation of Pb

continues, though at markedly lower rates. Th e large pool of Pb bound in soils may potentially

be a threat to aquatic ecosystems (see Section AX7.2), depending on its rate of release from the

soil. Early estimates of the residence time of Pb in the forest floor ranged from 220 to 5,000

years (Benninger et al., 1975; Friedland and J ohnson, 1985; Turner et al., 1985). However, more

recent literature suggests that Pb is transported mo re rapidly within soil profiles than previously

believed. The pool of Pb in forest floor soils of the northeastern United States declined

significantly in the late 20th century. Friedland et al. (1992) reported a 12% decline in the

amount of Pb in forest floor soils at 30 site s in the region between 1980 and 1990, a much greater

decline than would be expected for a pool with a residence time of 220 to 5,000 years.

At Hubbard Brook, the pool of Pb in the fo rest floor declined by 29% between 1977 and 1987,

an even more rapid rate of loss than reported by Friedland et al. (1992) . More recently, Evans

et al. (2005) reported significan t declines in the Pb content of forest floor soils in the

northeastern United States and eastern Canada between 1979 and 1996. The magnitude of the

decrease in Pb content was greates t at their sites in southern Verm ont, and smallest at sites on the

Gaspe Peninsula in Quebec, reflecting the historic gradient in Pb deposition in the region. At the

Vermont site, the Pb concentrati on in the litter layer (Oi horizon) was 85% lower in 1996 than in

1979. In the Gaspe peninsula of Quebec, the decrease was only 50%.

Since drainage water Pb concentrations remain low, the Pb released from forest floor soils

in the past has been largely immobilized in mineral soils (Miller a nd Friedland, 1994; Johnson

et al., 1995a; Johnson and Petras, 1998; Watmou gh and Hutchinson, 2004; Johnson et al., 2004).

This is supported by evidence from Pb-isot ope analyses. Gasoline-derived Pb has a 206 

# Pb: 207 

# Pb

ratio that can be easily discriminated from Pb in the rocks from which soils are derived. Using

isotopic mixing models with gasoline-Pb and Pb in soil parent materials as end members,

a number of researchers have documented the ac cumulation of pollutant Pb in mineral soils

(Bindler et al., 1999; Kaste et al., 2003; Watmough and Hutchinson, 2004; Bacon and Hewitt,

2005; Steinnes and Friedland, 2005). In a ha rdwood stand on Camel’s Hump Mountain in

Vermont, as much as 65% of the pollutant Pb deposited to the stand ha d moved into mineral

# AX7-105 horizons by 2001 (Kaste et al., 2003). In a spruce-fir stand, cont aining a thicker organic forest

floor layer, penetration of pollutant Pb into the mineral soil was much lower.

This recent research has resulted in a reeval uation of the turnover time of Pb in forest

floor soils. The Camel’s Hump data suggest that Pb resides in the forest floor of deciduous

stands for about 60 years and about 150 years in coniferous stands (Kaste et al., 2003). These

values are somewhat greater than those publis hed previously by Miller and Friedland (1994),

who used a Pb budget approach. Extremely ra pid turnover of Pb was observed in some

hardwood forest floor soils in south-central Ontario (Watmough et al., 2004). Their estimated

turnover times of 1.8 to 3.1 years are much lower than any other published values, which they

attribute to the mull-type forest floor at their sites. Mull-type forest floors are normally underlain

by organic-rich A horizons, capable of immobilizing Pb released from the forest floor. Indeed,

at the same site in Ontario, Watmough and Hutchi nson (2004) found that 90% of the pollutant Pb

could be found in this A horizon.

The time period over which the accumulated Pb in soils may be released to drainage

waters remains unclear. If Pb moves as a pulse through the soil, there may be a point in the

future at which problematic Pb concentrations occur. However, several authors have argued

against this hypothesis (Wang and Benoit, 1997; Kaste et al., 2003; Watmough et al., 2004),

contending that the strong linkage between Pb and DOM will result in a temporally dispersed

release of Pb in the form of Pb-DOM complexes. Thus, the greatest threat is likely to be in the

most highly contaminated areas surrounding point sources of Pb, where the amount of Pb

accumulated in the soil is high, and the death of vegetation has resulted in reduced soil organic

matter levels.

AX7.1.4.4 Summary

Atmospheric Pb pollution has resulted in the accumulation of Pb in terrestrial ecosystems

throughout the world. In the Unite d States, pollutant Pb represen ts a significant fraction of the

total Pb burden in soils, even in sites remote from smelters and other industrial plants. However,

few significant effects of Pb pollution have been obs erved at sites that are not near point sources

of Pb. Evidence from precipitation collection and sediment analyses indicates that atmospheric

deposition of Pb has declined dramatically (>95%) at sites unaffected by point sources of Pb, and

# AX7-106 there is little evidence that Pb accumulated in soils at these sites represents a threat to

groundwaters or surface water supplies.

The highest environmental risk for Pb in terrest rial ecosystems exists at sites within about

50 km of smelters and other Pb-emitting indus trial sites. Assessing the risks specifically

associated with Pb is difficult, because these si tes also experience elevated concentrations of

other metals and because of effects related to SO 2 

# emissions. The concentrations of Pb in soils,

vegetation, and fauna at these sites can be two to three orders of magnitude higher than in

reference areas (see Sections AX7.1.2 and AX7.1.4.2). In the most extreme cases, near smelter

sites, the death of vegetation causes a near-compl ete collapse of the detr ital food web, creating a

terrestrial ecosystem in which energy and nutrien t flows are minimal. More commonly, stress in

soil microorganisms and detritivores can cause reducti ons in the rate of decomposition of detrital

organic matter. Although there is little evidence of significant bioa ccumulation of Pb in natural

terrestrial ecosystems, reductions in microbial and detritivorous populations can affect the

success of their predators. Thus , at present, industrial point so urces represent the greatest Pbrelated threat to the maintenance of sustainable, healthy, diverse, and hi gh-functioning terrestrial

ecosystems in the United States.



# AX7.2 AQUATIC ECOSYSTEMS

AX7.2.1 Methodologies Used in Aquatic Ecosystem Research

As discussed in previous sections, aerial deposition is one source of Pb deposition to

aquatic systems. Consequently, to develop air quality criteria for Pb, consideration must be

given to not only the environmental fate of Pb, but also to the environmental effects of Pb in the

aquatic environment through consid eration of laboratory toxicity studies and field evaluations.

Perhaps the most straightforward approach for eval uating the effects of Pb is to consider extant

criteria for Pb in aquatic ecosystems, i.e., wate r and sediment quality criteria. A key issue in

developing Pb water and sediment criteria that are broadly appli cable to a range of water bodies

is properly accounting for Pb bioa vailability and the range in speci es sensitivities. This section

summarizes how these criteria are derived, the types of toxicity studies considered, and key

factors that influence the bioavailability of Pb in surface water and sediment to aquatic life.

Because Pb in the aquatic environment is often associated with other metals (e.g., cadmium,

# AX7-107 copper, zinc), the importance of considering the toxicity of metal mixtures is also discussed.

Finally, some issues related to background Pb con centrations are briefly addressed. It is beyond

the scope of this section to review all methodologies in aqua tic system research, but good

reviews can be found in summary books , such as Rand et al. (1995).

AX7.2.1.1 Analytical Methods

Common analytical methods for measuring Pb in the aquatic environment are summarized

in Table AX7-2.1.1. For relevance to the ambien t water quality criteria (AWQC) and sediment

quality criteria for Pb discussed below, minimum detection limits should be in the low parts per

billion (ppb) range for surface water and the low parts per million (ppm) range for sediment.

Table AX7-2.1.1. Common Analytical Methods for Measuring Lead in Water,
Sediment, and Tissue

Analysis Type Analytical Method

Direct-Aspiration (Flame) Atomic Absorption Spectroscopy
(AAS) EPA SW-846 Method 7420 a



# , EPA Method 239.1 b



# , Standard Method 3111 c



# Graphite Furnace Atomic Absorption Spectroscopy
(GFAAS) EPA SW-846 Method 7421 a



# , EPA Method 239.2 b



# , Standard Method 3113 c



# Inductively Coupled Plasma
(ICP) EPA SW-846 Method 6010B a



# , EPA Method 200.7 b



# , Standard Method 3120 c



# Inductively Coupled Plasma-Mass Spectrometry
(ICP-MS) EPA SW-846 Method 6020 a



# , EPA Method 200.8 b

a 

# U.S. Environmental Protection Agency (1986c) Test Methods for Evaluating Solid Waste, Physical/Chemical

Methods (SW-846). Third Edition, September 1986; Final Updates I (7/92), IIA (8/93), II (9/94), IIB (1/95),
III (12/96), IIIA (4/98), IIIB (11/04).

b 

# U.S. Environmental Protection Agency (1991) Methods for the Determination of Metals in Environmental

Samples. EPA/600/4-91-010. June 1991 (Supplement I, EPA/600/R-94-111, May 1994).

c 

# American Public Health Association (1995) Standard Methods for the Examination of Water and Wastewater,

19th Edition. American Public Health Association, American Water Works Association, Water Pollution

Control Federation.



# In addition to the methods presented in Table AX7-2.1.1, many of the methods discussed

in Section AX7.1.1 can be applied to suspended solids and sediments collected from aquatic

# AX7-108 ecosystems. Just as in the terrestrial environmen t, the speciation of Pb and other trace metals in

natural freshwaters and seawater plays a crucia l role in determining their reactivity, mobility,

bioavailability, and toxicity. Many of the same speciation techniques employed for the

speciation of Pb in terrestrial ecosystems (s ee Section AX7.1.1 and AX7.1.2) are applicable in

aquatic ecosystems.

There is now a better understa nding of the potential effects of sampling, sample handling,

and sample preparation on aqueous-phase metal sp eciation. Thus, a need has arisen for dynamic

analytical techniques that are able to capture a metal’s speciation, in -situ and in real time. Some

of these recently developed dynamic trac e metal speciation techniques include:

• Diffusion gradients in thin-film gels (DGT)

• Gel integrated microelectrodes combined with voltammetric in situ profiling
(GIME-VIP)

• Stripping chronopoten tiometry (SCP)

• Flow-through and hollow fiber permeation liquid membranes (FTPLM and HFPLM)

• Donnan membrane technique (DMT)

• Competitive ligand-exchange/stripping voltammetry (CLE-SV)

Various dynamic speciation techniques were co mpared in a study by Si gg et al. (2006) using

freshwaters collected in Switzer land. They found that techni ques involving in-situ measurement

(GIME-VIP) or in-situ exposure (DGT, DMT, and HFPLM) appeared to the most appropriate for

avoiding Pb and other trace metal speciation artif acts associated sampling and sample handling.

AX7.2.1.2 Ambient Water Qualit y Criteria: Development

The EPA’s procedures for deriving AWQC are described in Stephan et al. (1985) and are

summarized here. With few exceptions, AWQC are derived based on data from aquatic toxicity

studies conducted in the laborator y. In general, both acute (sho rt term) and chronic (long term)

AWQC are developed. Depending on the species, th e toxicity studies considered for developing

acute criteria range in length from 48 to 96 hours. Acceptable endpoints for acute AWQC

development are mortality and/or immobilization, expressed as the median lethal concentration

(LC 50 

# ) or median effect concentration (EC 50 

# ). For each species, the geometric mean of the

acceptable LC 50 

# /EC 50 

# data is calculated to determine th e species mean acute value (SMAV).

# AX7-109 For each genera, the geometric mean of the releva nt SMAVs is then calculated to determine the

genus mean acute value (GMAV). The GMAVs are then ranked from high to low, and the final

acute value (FAV; the 5th per centile of the GMAVs, based on the four GMAVs surrounding the

5th percentile) is determined. Because the FAV is based on LC 50 

# /EC 50 

# values (which represent

unacceptably high levels of effect), the FAV is di vided by two to estimate a low-effect level.

This value is then termed the acute criterion, or crite rion maximum concentration (CMC). Based

on the most recent AWQC document for Pb (U .S. Environmental Protection Agency, 1985),

Table AX7-2.1.2 shows the freshwater SMAVs and GMAVs for Pb, and the resulting freshwater

CMC. Note that the freshwater AWQC are norma lized for the hardness of the site water, as

discussed further below in Section AX7.2.1.3.

Table AX7-2.1.2. Development of Current Acute Freshwater Criteria for Lead
(U.S. Environmental Protection Agency, 1985) 1



# Rank Species GMAV (μg/L) SMAV (μg/L)

10 Midge ( Tanytarsus dissimilis ) 235,900 235,900



# 9 Goldfish ( Carassius auratus ) 101,100 101,100



# 8 Guppy ( Poecilia reticulata ) 66,140 66,140



# 7 Bluegill ( Lepomis macrochirus ) 52,310 52,310



# 6 Fathead minnow ( Pimephales promelas ) 25,440 25,440



# 5 Brook trout ( Salvelinus fontinalis ) 4,820 4,820



# 4 Rainbow trout ( Oncorhynchus mykiss ) 2,448 2,448



# 3 Snail ( Aplexa hypnorum ) 1,040 1,040



# 2 Cladoceran ( Daphnia magna ) 447.8 447.8



# 1 Amphipod ( Gammarus pseudolimnaeus ) 142.6 142.6



# FAV = 67.54 μg/L

CMC = 33.77 μ g/L

1 

# All values are normalized to a hardness of 50 mg/L (see Section AX7.2.1.3).

# AX7-110 To develop chronic AWQC, acceptable chronic toxicity studies should encompass the full

life cycle of the test organism, although for fish, early life stage or partia l life cycle toxicity

studies are considered accepta ble. Acceptable endpoints include reproduction, growth and

development, and survival, with the effect levels expressed as the chronic value, which is the

geometric mean of the no-obser ved-effect concentration (NOEC) 1 

# and the lowest-observedeffect concentration (LOEC) 2 

# . Although a chronic criterion c ould be calculated as the 5th

percentile of genus mean chronic values (GMCVs), sufficient chronic toxic ity data are generally

lacking, as is the case for Pb. Consequently, an acute-chronic ratio (ACR) is typically applied to

the FAV to derive the chronic criterion. As the name implies, the ACR is the ratio of the acute

LC 50 

# to the chronic value, based on studies with th e same species and in the same dilution water.

For Pb, the final ACR is 51.29, which results in a final chronic value (FCV) of 1.317 μg/L (at a

hardness of 50 mg/L). The U.S. EPA guidelines fo r developing AWQC (Stephan et al., 1985) are

now more than 20 years old and thus are not re flective of scientific advances in aquatic

toxicology and risk assessment that have developed since the 1980s. For example, the

toxicological importance of dietar y metals has been increasingly recognized and approaches for

incorporating dietary metals into regulatory criteria are being ev aluated (Meyer et al., 2005).

Other issues include consideration of certain su blethal endpoints that are currently not directly

incorporated into AWQC development (e.g., endo crine toxicity, behavi oral responses) and

protection of threatened and e ndangered (T&E) species (U.S. E nvironmental Protection Agency,

2003). In deriving appropriate and scientifically defensible air qua lity criteria for Pb, it will be

important that the state-of-the-science for metals toxicity in aquatic systems be incorporated into

the development process.

Subsequent sections summari ze some of the toxicity studies that meet the AWQC

development guidelines, with an emphasis on key studies published since the last Pb AWQC

were derived in 1984.

1 

# The NOEC is the highest concentration tested that di d not result in statistically significant effects relative

to the control.

2 

# The LOEC is the lowest concentration tested that re sulted in statistically significant effects relative to

the control.

# AX7-111 AX7.2.1.3 Ambient Water Quality Cr iteria: Bioavailability Issues

In surface waters, the environmental fate of metal contaminants is mitigated through

adsorption, complexation, chelation, and other proce sses that affect bioavaila bility. The toxicity

of divalent cations tends to be hi ghest in soft waters with low c oncentrations of dissolved organic

matter and suspended particles. In an acidic envi ronment (pH <4), the ioni c form of most metals

generally predominates and is considered to be the more toxic form. As the pH increases,

carbonate, oxide, hydroxide, and sulfide complexes of the metals tend to predominate, and tend

to be less toxic (Flore nce, 1977; Miller and Mackay, 1980). The portion of dissolved metal

available for uptake or bioaccumulation is influe nced by modifying factors that “sequester” the

metal in an environmental matrix, thereby reducing the bioavailability of the metal at the sites of

action. Metals can become comp lexed (bound) to a ligand that can make metals either more

toxic (via transport mechanisms) or less toxic (by changing the metal’s biological activity).

Metals that complex tightly to ligands generally are not readil y bioavailable and, thus, are less

toxic to aquatic biota than th eir free-metal ion counterpart s (Carlson et al., 1986; McCarthy,

1989). There are many kinds of ligands, organic and inorganic, as well as natural and manmade. Ligands found in natural surface waters a nd municipal and industrial effluent discharges

include glycine, ammonia, oxalate, humic or fulvic acids, hydroxide , carbonate, bicarbonate,

chloride, and hydrogen sulfide (Stumm and Morg an, 1970; Martin, 1986; Pagenkopf, 1986).

Recognizing the importance of calcium and magnesium ions (hardness) in modifying Pb

toxicity, the current freshwater AWQC for Pb are normalized based on the hardness of the site

water. The acute freshwater criteria, for exampl e, are 30, 65, and 136 μg/L at hardness levels of

50, 100, and 200 mg/L (as CaCO 3 

# ). Although it has been known for some time that other water

quality parameters such as pH, dissolved or ganic carbon (DOC), and alkalinity affect the

bioavailability of metals to aqua tic biota, it was the relatively recent development of the biotic

ligand model (BLM) that allows for AWQC to pote ntially consider all of these factors. Paquin

et al. (2002) provided a thorough re view of the factors influenci ng metal bioavailability and how

research over the last few decades has culmin ated in the development of the BLM.

By understanding the binding affinities of vari ous natural ligands in surface waters and

how the freshwater fish gill inte racts with free cations in the water, one can predict how metals

exert their toxic effects (Schwart z et al., 2004). Models developed prior to the BLM are the freeion activity model (FIAM) and the gill surface interaction model (GSIM). The FIAM accounts

# AX7-112 for the binding of free-metal ion and other metal complexes to the site of toxic action in an

organism; and it also considers competition be tween metal species and other cations (Paquin

et al., 2002). The GSIM is fundamentally simila r to the FIAM in that it accounts for competition

between metal ions and hardness cations at the ph ysiological active gill sites, but whereas the

FIAM is largely conceptual, the GSIM was used in interpreting toxicity test results for individual

metals and metal mixtures (Pagenkopf, 1983). The BLM was adapted from the GSIM and uses

the biotic ligand, rather than the fish gill as the site of toxic action (Di Toro et al., 2001; Paquin

et al., 2002). This approach, ther efore, considers that the extern al fish gill surface contains

receptor sites for metal binding (Schwartz et al., 2004) and that acute toxicity is associated with

the binding of metals to defined sites (biotic ligands) on or with in the organism (Paquin et al.,

2002). The model is predicated on the theory that mortality (or other toxic effects) occurs when

the concentration of metal bound to biotic ligan d exceeds a threshold concentration (Di Toro

et al., 2001; Paquin et al., 2002). Free metal catio ns “out compete” other cations and bind to the

limited number of active receptor sites on the gill surface, which may ultimately result in

suffocation and/or disruption of io noregulatory mechanisms in the fi sh, leading to death (Di Toro

et al., 2001; Paquin et al., 2002). Because the BLM uses the biotic ligand (not the fish gill) as

the site of action, the model can be applied to other aquatic orga nisms, such as crustaceans,

where the site of action is directly exposed to the aqueous environment (D i Toro et al., 2001).

Although the BLM is currently be ing considered as a tool fo r regulating metals on a sitespecific basis, there are potential limitations in using the BLM to regulate metals in surface

waters that should be understood in developing air quali ty criteria for lead. For example, BLMs

developed to-date have focused on acute mort ality/immobilization endpoints for fish and

invertebrates. Chronic exposures are typically of greatest regulatory concern, but chronic BLMs

to date have received limited attention (D e Schamphelaere and Janssen, 2004). In addition,

BLMs account for uptake of dissolved metal, but dietary metals have also been shown to

contribute to uptake by aquatic biota and, in some cases, increased toxicity. Besser et al. (2005)

observed that chronic (42-day) Pb toxicity to the amphipod Hyalella az teca was greater from a

combined aqueous and dietary exposure than from a water-only exposure and the authors

conclude that estimates of chronic toxicity th resholds for Pb should consider both aqueous and

dietary exposure routes. The feasibility of incorporating dietary metals into BLMs is under

investigation. Another important issue that must be addressed in developing and applying a

# AX7-113 BLM in AWQC development is the type of disso lved organic matter used in model development

relative to the types of dissolved organic matter at the site of interest. Richar ds et al. (2001)

demonstrated that natural organic matter (NOM) of different types differentially influenced Pb

and Cu accumulation by gills of rainbow trout. Th ere are also other ligands not accounted for in

the BLM that require more research. Bianch ini and Bowles (2002) emphasized the importance

of reduced sulfur as a metal ligand, limitations in scientific knowledge on reduced sulfur, and

provided recommendations for studi es necessary to incorporate sulfide ligands into the BLM.

The U.S. EPA is currently revising the aquatic life AWQC for lead, which will include

toxicity data published after th e 1985 AWQC were released and incorporation of the BLM is

being evaluated. If an acute BLM is incorporat ed into the revised AWQC for lead, the chronic

criteria would likely be estimated using an A CR (the same approach used when the acute

criterion is based on empirical toxicity data; see above).

AX7.2.1.4 Sediment Quality Criteria: Development and Bioavailability Issues

As with metals in surface waters, the environmental fate of metal contaminants in

sediments is moderated through various binding pro cesses that reduce the concentration of free,

bioavailable metal. Sediments function as a si nk for Pb, as with most metals. Lead compounds

such as Pb-carbonates, Pb-sulfates, and Pb-sul fides predominate in se diments (Prosi, 1989).

Total Pb has a higher retention time and a higher per centage is retained in sediments compared to

copper and zinc (Prosi, 1989). Lead is primar ily accumulated in sediments as insoluble Pb

complexes adsorbed to suspended particulate matter. Naturally occurring Pb is bound in

sediments and has a low geochemical mobility (Prosi, 1989). Organic-sulfide and moderately

reducible fractions are less mobile, whereas catio n-exchangeable fractions and easily-reducible

fractions are more mobile and more readily bi oavailable to biota (Prosi, 1989). Most Pb

transported in surface waters is in a particulate fo rm, originating from the erosion of sediments in

rivers or produced in the wa ter column (Prosi, 1989).

Sediment quality criteria have yet to be adopted by the EPA, but an equilibrium

partitioning procedure has recently been publis hed (U.S. Environmental Protection Agency,

2005c). The EPA has selected an equilibrium partitioning approach because it explicitly

accounts for the bioavailability of metals. This approach is based on mixtures of cadmium,

copper, Pb, nickel, silver, and zinc. Equilibrium partitioning (EqP) theory predicts that metals

# AX7-114 partition in sediment between aci d-volatile sulfide, pore water, benthic organisms, and other

sediment phases such as organic carbon. When the sum of the molar concentrations of

simultaneously extracted metal ( ∑ SEM) minus the molar concentration of AVS is less than zero,

it can accurately be predicted that sediments are not toxic because of these me tals. Note that this

approach can be used to predict the lack of t oxicity, but not the presen ce of toxicity. It is

important to emphasize that metals must be ev aluated as a mixture us ing this approach.

If individual metals, or just two or th ree metals, are measured in sediment, ∑ SEM would be

misleadingly small and it may inaccurately appear that ∑ SEM / AVS is less than 1.0.

If ∑ SEM / AVS is normalized to the organic carbon fraction (i.e., ( ∑ SEM / AVS)/ f

OC 

# ),

mortality can be more reliably predicted by acco unting for both the site-specific organic carbon

and AVS concentrations. When evaluating a me tal mixture containing cadmium, copper, Pb,

nickel, silver, and zinc, the following predicti ons can be made (U.S. Environmental Protection

Agency, 2005c):

• A sediment with (SEM / AVS)/ f

OC 

# < 130 μmol/g OC 

# should pose low risk of adverse biological effects due to these metals.

• A sediment with 130 μmol/g OC 

# < (SEM / AVS)/ f

OC 

# < 3000 μmol/g OC 

# may have adverse
biological effects due to these metals.

• In a sediment with (SEM / AVS)/ f

OC 

# > 3000 μmol/g OC 

# , adverse biological effects may
be expected.

A third approach is to measure pore water c oncentrations of cadmium, copper, Pb, nickel,

and zinc and then divide the concentrations by their respective FCVs. If the sum of these

quotients is <1.0, these metals are not expected to be toxic to benthic organisms.

It should be noted that although EPA ha s endorsed the AVS-SEM approach for

developing sediment guidelines, ot her investigators do not necessa rily agree, as the AVS-SEM

approach may not be relevant to benthic organisms that ingest sedi ment particles. For example,

Griscom et al. (2002) found that metals associat ed with either reduced or oxidized sediment

particles can be assimilated by deposit and suspen sion feeding bivalve species due to the low pH

and moderate reducing conditions in bivalve guts. Although Lee et al. (2000) agreed that the

AVS-based approach may be appropriate for pr otecting some benthic organisms from acute

toxicity associated w ith exposure to very high pore water concentrations of metals, they

questioned whether the AVS-based approach is relevant to less contaminated sediments under

# AX7-115 more natural conditions with ver tical stratification of oxygen concentrations and, hence, varying

levels of AVS. The authors concluded that impor tant uncertainties remain in the application of

the AVS-SEM approach as a regulatory tool. Similarly, some studies suggest that AVS-SEM

measurements in the natural environment must be interpreted cautiously as AVS can be quite

variable with sediment depth and season (Van de n Berg et al., 1998). Finally, Long et al. (1998)

critically compared the ability of AVS-SEM and dry weight-normalized con centrations to predict

toxicity of sediment-associated tr ace metals. Based on an analysis of 77 field-collected sediment

samples, Long et al. (1998) found that dry weig ht-normalized concentrations were equally or

slightly more accurate than AVS-SEM in predic ting non-toxic and toxic results in laboratory

bioassays. Long et al. suggests th at a limitation of the AVS-SEM a pproach is that the criteria

were not derived from field studie s with mixture of toxic chemical s and thus may be less relevant

to sites comprising complex chemical mixtures . Thus, although the AVS-SEM approach for

developing sediment quality criter ia is being pursued by the U.S. EPA, there is clearly not

scientific consensus on this approach, at least not for all circumstances.

Many alternative approaches for developing sediment quality guidelines are based on

empirical correlations between metal concentrations in sediment to associated biological effects,

based on sediment toxicity test s (Long et al., 1995; Ingersoll et al., 1996; MacDonald et al.,

2000). However, these guidelines are based on tota l metal concentrations in sediment and do not

account for the bioavailability of metals betw een sediments. Sediment quality guidelines

proposed for Pb from these other sources are shown in Table AX7-2.1.3.

Table AX7-2.1.3. Recommended Sediment Quality Guidelines for Lead

Source Water Type Guideline Ty pe Conc. (mg/kg dw)



# MacDonald et al. (2000) Freshwater TEC

PEC 35.8

128

Ingersoll et al. (1996) Freshwater ERL

ERM 55

99

Long et al. (1995) Saltwater ERL

ERM 46.7

218

TEC = Threshold effect concentration; PEC = Probable effect concentration; ERL = Effects range – low; ERM = Effects range – median

# AX7-116 AX7.2.1.5 Metal Mixtures

As discussed above, the EPA’s current approach for developing sediment criteria for Pb

and other metals is to consider the molar sum of the metal concentrations ( ∑ SEM). Although a

similar approach has not been a pplied to AWQC, metal mixtures have been shown to be more

toxic than individual metals (Spe har and Fiandt, 1986; Enserink et al., 1991). Spehar and Fiandt

(1986) evaluated the acute and chronic toxicity of a metal mixture (arsenic, cadmium, chromium,

copper, mercury, and Pb) to fathead minnows ( Pimephales promelas ) and a daphnid

( Ceriodaphnia dubia ). In acute tests, the joint toxicity of these metals was observed to be more

than additive for fathead minnows and nearly strictly additive for daphnids. In chronic tests, the

joint toxicity of the metals was less than a dditive for fathead minnows and nearly strictly

additive for daphnids. One approach for considering the additive toxi city of Pb with other metals

is to use the concept of toxic uni ts (TUs). Toxic units for each component of a metal mixture are

derived by dividing metal concentrations by their respective acute or chro nic criterion. The TUs

for all the metals in the mixture are then summed. A ∑ TU > 1.0 suggests the metal mixture is

toxic (note that this is the sa me approach as discussed above for developing metal sediment

criteria based on pore water concentrations). According to Norwood et al. (2003), the TU

approach is presently the most appropriate mode l for predicting effects of metal mixtures based

on the currently available toxicity data. Howeve r, it should also be emphasized that the TU

approach is most appropriate at a screening level, because the true toxicity of the mixture is

dependent on the relative amounts of each metal. The TU approach is also recommended with

mixtures containing less than six metals.

Lead and other metals often co-occur in sedi ments with other toxicants, such as organic

contaminants. Effects-based sediment quality gu idelines (SQGs) have been developed over the

past 20 years to aid in the in terpretation of the relationships between complex chemical

contamination and adverse biological effects (Long et al., 2006). Mean sediment quality

guideline quotients (mSQGQs) can be calculated by dividing the concentrations of chemicals in

sediments by their respective SQGs and then ca lculating the mean of the quotients for the

individual chemicals. Long et al. (2006) perfor med a critical review of this approach and found

that it reasonably predicts the incidence and magnitude of toxici ty in laboratory tests and the

incidence of impairment to benthic commun ities increases incrementally with increasing

mSQGQs. However, the authors po inted out some of the limitations of this approach, such as a

# AX7-117 lack of agreement on the level of mSQGQs, masking of an indivi dual chemical’s effect due to

data aggregation, lack of SQGs for all chemi cals of concern, and mSQGQs were not initially

derived as a regulatory standard or criterion, thus there is a reluctance to use them in

enforcement or remediati on (Long et al., 2006).

For assessing Pb effects on aquatic ecosystems, it is not truly feasible to account for metal

mixtures, because these will obviously vary highly fr om site to site. However, the toxicity of

metal mixtures in surface water should be considered on a site-specific basis.

AX7.2.1.6 Background Lead

Because Pb is naturally occurring, it is found in all environmental compartments

including surface water, sediment, and aquatic biot a. Background Pb concentrations are spatially

variable depending on geological fe atures and local characteristic s that influence Pb speciation

and mobility. In the European Union risk assessments for metals, an “added risk” approach has

been considered that assumes only the amount of metal added above background is relevant in a

toxicological evaluation. However, this a pproach ignores the po ssible contribution of

background metal levels to toxic effects, and background metal levels are regionally variable,

precluding the approach from be ing easily transferable between sites. In terms of deriving

environmental criteria for Pb, b ackground levels should be consider ed on a site-specific basis if

there is sufficient information that Pb concentr ations are naturally el evated. As discussed

previously, the use of radiogenic Pb isotope s is useful for sour ce apportionment.



# AX7.2.2 Distribution of Lead in Aquatic Ecosystems

Atmospheric Pb is delivered to aquatic ecosystems primarily through deposition (wet

and/or dry) or through erosiona l transport of soil pa rticles (Baier and Healy, 1977; Dolske and

Sievering, 1979; and Yang and Rose, 2005). A numb er of physical and chemical factors govern

the fate and behavior of Pb in aquatic systems. The EPA summa rized some of these controlling

factors in the 1986 Lead AQCD (U .S. Environmental Protection Agency, 1986a). For example,

the predominant form of Pb in the environment is in the divalent (Pb 2+ 

# ) form and complexation

with inorganic and organic li gands is dependent on pH (L overing, 1976; Rickard and Nriagu,

1978). A significant portion of Pb in the aquatic environment exists in the undissolved form

(i.e., bound to suspended particulate ma tter). The ratio of Pb in susp ended solids to Pb in filtrate

# AX7-118 varies from 4:1 in rural streams to 27:1 in urban streams (Getz et al ., 1977). In still waters, Pb is

removed through sedimentation at a rate determ ined by temperature, pH, oxidation-reduction

(redox) potential, organic content, grain size, and chemical form of Pb in the water and

biological activities (J enne and Luoma, 1977). Since the publication of the 1986 Lead AQCD

(U.S. Environmental Protection Agency, 1986a), knowledge of the properties of Pb in aquatic

ecosystems has expanded. This section will provid e further detail on the chemical species and

the environmental factors affecti ng speciation of Pb in the aqua tic environment. In addition,

quantitative distributions of Pb in water, sedime nt, and biological tissues will be presented for

aquatic ecosystems throughout the United States. Finally, recent studies discussing the tracing of

Pb in aquatic systems will be summarized.

AX7.2.2.1 Speciation of Lead in Aquatic Ecosystems

The speciation of Pb in the aquatic envir onment is controlled by many factors. The

primary form of Pb in aquatic environments is divalent (Pb 2+ 

# ), while Pb 4+ 

# exists only under

extreme oxidizing conditions (Rickard and Nriagu, 1978). Labile forms of Pb (e.g., Pb 2+



# ,

PbOH + 

# , PbCO 3 

# ) are a significant portion of the Pb inputs to aquatic systems from atmospheric

washout. Lead is typically present in acidic aquatic environments as PbSO 4 

# , PbCl 4 

# , ionic Pb,

cationic forms of Pb-hydroxide, and ordinary Pb -hydroxide (Pb(OH) 2 

# ). In alkaline waters,

common species of Pb include ani onic forms of Pb-carbonate (Pb(CO 3 

# )) and Pb(OH) 2



# . Speciation models have been developed based on the chemical equilibrium model developed by

Tipping (1994) to assist in examining metal speciation. The EPA MINT EQA2 computer model

(http://www.epa.gov/ceampubl/mmedia/minteq/) is one such equilibrium speciation model that

can be used to calculate the e quilibrium composition of dilute a queous solutions in the laboratory

or in natural aqueous systems. The model is useful for calculating the equilibrium mass

distribution among dissolved species, adsorbed species, and multiple solid phases under a variety

of conditions, including a gas phase with constant partial pressures. In addition to chemical

equilibrium models, the speciation of metals is important from a toxicological perspective.

The BLM was developed to study the toxicity of metal ions in a quatic biota and was previously

described in Section AX7.2.1.3. Fu rther detail on speciation m odels is not provided herein,

rather a general overview of major speciation principles are characterized in the following

sections.

# AX7-119 Acidity (pH)

Freshwater

Most of the Pb in aquatic environments is in the inorganic form (Sadiq, 1992). The

speciation of inorganic Pb in freshwater aquatic ecosystem s is dependent upon pH and the

available complexing ligands. Solubility vari es according to pH, temperature, and water

hardness (Weber, 1993). Lead ra pidly loses solubility above pH 6.5 (Rickard and Nriagu, 1978)

and as water hardness increases. In freshwater s, Pb typically forms strong complexes with

inorganic OH ! 

# and CO 3 2 ! 

# and weak complexes with Cl ! 

# (Long and Angino, 1977; Bodek et al.,

1988). The primary form of Pb at low pH ( # 6.5) is predominantly Pb 2+ 

# and less abundant

inorganic forms include Pb(HCO) 3 

# , Pb(SO4) 2 2 ! 

# , PbCl, PbCO 3 

# , and Pb 2 

# (OH) 2 

# CO 3



# (Figure AX7-2.2.1). At higher pH ( ∃ 7.5), Pb forms hydroxide complexes (PbOH + 

# , Pb(OH) 2 

# ,

Pb(OH) 3 ! 

# , Pb(OH) 4 2 ! 

# ).

Figure AX7-2.2.1. Distribution of aqueous lead species as a function of pH based on
a concentration of 1 μg Pb/L (U.S. Environmental Protection
Agency, 1999).

# AX7-120 Organic compounds in surface waters may originate from natural (e.g., humic or fulvic

acids) or anthropogenic sources (e .g., nitrilotriacetoni trile and ethylenediaminetetraacetic acid

[EDTA]) (U.S. Environmental Protection Agenc y, 1986b). The presence of organic complexes

has been shown to increase the rate of solu tion of Pb bound as Pb-sulfide (Lovering, 1976).

Soluble organic Pb compounds are present at pH values near 7 and may remain bound at pH

values as low as 3 (Lovering, 1976 ; Guy and Chakrabarti, 1976). At higher pH (7.4 to 9),

Pb-organic complexes are partially decompose d. Water hardness and pH were found to be

important in Pb-humic acid interactions (O ’Shea and Mancy, 1978). An increase in pH

increased the concentration of exchangeable Pb complexes, while an increase in hardness tended

to decrease the humic acid-Pb interactions. Thus, the metals involved in water hardness

apparently inhibit the exchangeable inte ractions between metals and humic acids.

Marine Water

In marine systems, an increase in salin ity increases complexi ng with chloride and

carbonate ions and reduces the amount of free Pb 2+ 

# . In seawaters and estu aries at low pH, Pb is

primarily bound to chlorides (PbCl, PbCl 2 

# , PbCl 3 !

 

# , PbCl 4 2 ! 

# ) and may also form inorganic

Pb(HCO) 3 

# , Pb(SO4) 2 2 ! 

# , or PbCO 3 

# . Elevated pH in saltwater environments results in the

formation of Pb hydroxides (PbOH + 

# , Pb(OH) 2 

# , Pb(OH) 3 ! 

# , Pb(OH) 4 2 ! 

# ) (Figure AX7-2.2.2).

A recent examination of Pb species in seawater as a function of chloride concentration suggested

that the primary species were PbCl 3 ! 

# > PbCO 3 

# > PbCl 2 

# > PbCl + 

# > and Pb(OH) + 

# (Fernando, 1995).

Lead in freshwater and seawater systems is highly complexed w ith carbonate ligands suggesting

that Pb is likely to be highly available fo r sorption to suspended materials (Long and Angino,

1977).

Current information suggests that inorgani c Pb is the dominant form in seawater;

however, it has been shown that organically bound Pb complexes make up a large portion of the

total Pb (Capodaglio et al., 1990).

Sorption

Sorption processes (i.e., partitioning of dissolv ed Pb to suspended particulate matter or

sediments) appear to exert a dominant effect on the distribution of Pb in the environment

(U.S. Environmental Protection Agency, 1979). Sorp tion of Pb results in the enrichment of

# AX7-121 Figure AX7-2.2.2. Lead speciation versus chloride content (Fernando, 1995).

bed sediments, particularly in environments with elevated organic matter content from

anthropogenic sources. Lead adso rption to aquatic sediments is co rrelated with pollution in sites

containing high levels of anthr opogenic organic content, even unde r acidic conditions (Tada and

Suzuki, 1982; Brook and Moore, 1988; Davis and Galloway, 1993; Botelho et al., 1994; Davis

et al., 1996). Particulate-bound forms are more of ten linked to urban runo ff and mining effluents

(Eisler, 2000).

Solid Pb complexes form when Pb precipitate s or adsorbs to suspended particulate matter

and sediments. Inorganic Pb adsorption to susp ended organic matter or sediments is dependent

on parameters such as, pH, salinity, water hard ness, and the composition of the organic matter

(U.S. Environmental Protection Agency, 1979). In addition to suspended organic matter, Pb can

adsorb to biofilms (i.e., bacteria) (Nelson et al ., 1995; Wilson et al., 2001). Adsorption typically

increases with increasing pH, increasing amounts of iron or manganese; and with a higher degree

of polarity of the particulate matter (e.g., clay s). Adsorption decreases with water hardness

(Syracuse Research Corporation, 1999). At higher pH, Pb precipitates as Pb(OH) + 

# and PbHCO 3 +



# into bed sediments (Weber, 1993). Conversely, at low pH, Pb is negatively sorbed (repelled

from the adsorbent surface) (U.S. Environmen tal Protection Agency, 1979; Gao et al., 2003).

In addition, Pb may be remobilized from sediment with a decrease in metal concentration in the

# AX7-122 solution phase, complexation with chelating ag ents (e.g., EDTA), and changing redox conditions

(Gao et al., 2003). Changes in water chemistr y (e.g., reduced pH or ionic composition) can

cause sediment Pb to become remobilized and potentially bioavailable to aquatic organisms

(Weber, 1993).

Biotransformation

Methylation may result in Pb remobiliza tion and reintroduction into the aqueous

environment compartment and its subsequent rel ease into the atmosphere (Syracuse Research

Corporation., 1999). However, methylation is not a significant e nvironmental pathway

controlling the fate of Pb in the aquatic environmen t. The microbial methylation of Pb in aquatic

systems has been demonstrated experimentall y, but evidence for natura l occurrence is limited

(Beijer and Jernelov, 1984; DeJonghe and Adams, 1986). Reisinger et al. (1981) examined the

methylation of Pb in the presence of numerous b acteria known to alkylate metals and did not find

evidence of Pb methylation unde r any test condition. Tetramet hyl-Pb may be formed by the

methylation of Pb-nitrate or Pb-chloride in sediments (Bode k et al., 1988). However,

tetramethyl-Pb is unstable and may degrade in ae robic environments after being released from

sediments (U.S. Environmental Protection Agenc y, 1986b). Methylated species of Pb may also

be formed by the decomposition of tetralkyl -Pb compounds (Radojevic and Harrison, 1987;

Rhue et al., 1992). Sadiq (1992) reviewed the me thylation of Pb compou nds and suggested that

chemical methylation of Pb is the dominant pr ocess and that biomethylation is of secondary

importance.

AX7.2.2.2 Spatial Distribution of Lead in Aquatic Ecosystems

National Water Quality Assessment (NAWQA)

The 1986 Lead AQCD (U.S. Environmental Pr otection Agency, 1986b) did not describe

the distribution and concentrati on of Pb throughout aquatic ecos ystems of the United States.

Consequently, an analysis of readily availabl e data on Pb concentrations was conducted to

determine the distributio n of Pb in the aquatic environment. Data from the United States

Geological Survey (USGS) National Water-Q uality Assessment (NAWQA) program were

queried and retrieved. NAWQA contains data on Pb concentrations in surface water, bed

sediment, and animal tissue for more than 50 ri ver basins and aquifers throughout the country,

# AX7-123 and it has been used by the EPA for describing na tional environmental concentrations for use in

developing AWQC. The authors recognize that the NAWQA program encountered analytical

challenges with the chemical analysis of Pb in surface waters. The analytical methods available

during the NAWQA program were not as sensi tive as methods currently applied today.

Therefore, analytical detection limits are elevat ed and a large portion of the data set contains

non-detected values. Nevertheless, this data provides a comprehensive overview of Pb

concentrations in U.S. surface waters that is suppl emented with data from other relevant studies.

The following sections describe the estimated concentrations of Pb from NAWQA and other

research programs.

NAWQA data are collected duri ng long-term, cyclical invest igations wherein study units

undergo intensive sampling for 3 to 4 years, followed by low-intensity monitoring and

assessment of trends every 10 years. The NAW QA program’s first cycle was initiated in 1991;

therefore, all available data are less than 15 years old. The second cycle began in 2001 and is

ongoing; data are currently av ailable through 30 September 2003. The NAWQA program study

units were selected to represent a wide variet y of environmental conditions and contaminant

sources; therefore, agricultural, urban, and natura l areas were all included. Attention was also

given to selecting sites covering a wide vari ety of hydrologic and ecological resources.

NAWQA sampling protocols are designed to pr omote data consistency within and among

study units while minimizing local-scale spatial va riability. Water-column sampling is

conducted via continuous monitoring, fixed-interval sampling, extreme-flow sampling, as well as

seasonal, high-frequency sampling in order to characterize spatial, temporal, and seasonal

variability as a function of hydr ologic conditions and contaminant sources. Sediment and tissue

samples are collected during low-flow periods during the summer or fall to reduce seasonal

variability. Where possible, sediment grab samples are collected al ong a 100-m stream reach,

upstream of the location of the water-column samp ling. Five to ten deposit ional zones at various

depths, covering left bank, right bank, and cente r channel, are sampled to ensure a robust

representation of each site. Fine-g rained samples from the surficial 2 to 3 cm of bed sediment at

each depositional zone are sampled and composited. Tissue samples are collected following a

National Target Taxa list and d ecision trees that help guide selection from that list to

accommodate local variability.

# AX7-124 The NAWQA dataset was chosen over other re adily available national databases (i.e. the

USEPA-maintained database for the STOrage a nd RETrieval [STORET] of chemical, physical,

and biological data), because the study design an d methods used to assess the water quality of

each study unit are rigorous and consistent, and, as such, these data may be presented with a high

level of confidence. This is in stark contrast to the STORET database, which essentially serves

as a depot for any organization wishing to share data they have generated. This lack of a

consistent methodology or QA/QC pr otocol has lead to the STORET data being highly qualified

and offered with only a mild leve l of confidence. Furthermore, because there is no standard for

site selection within STORET, the database may be biased toward contaminated sites. Finally,

and, perhaps most importantly, the majority of th e available Pb data in STORET predate the use

of clean techniques for Pb quantification.

The authors recognize the existen ce of several local and regiona l datasets that may be of

quality equal to NAWQA; however, due to the nati onal scope of this assessment, these datasets

were not included in the following statistical an alyses. However, because the NAWQA database

does not cover lakes and the marine/estuarine en vironment, and we were unable to identify any

monitoring data of similar quality, local and regional datasets were used in these cases to provide

general information on environmental Pb concentrations.

Data Acquisition and Analysis

The following data were downloaded for the entire United States (all states) from the

NAWQA website (http://water.us gs.gov/nawqa/index.html): site information, dissolved Pb

concentration in surface water (μ g/L), total Pb concentration (μg/g) in bed sediment (<63 μm) 3



# ,

and Pb concentration in animal tissue (μg/g dw). Using the land use classification given for each

site, the data were divided into two groups: “natural” and “ambient” (Table AX7-2.2.1).

All samples were considered to fall within th e ambient group (the combined contribution of

natural and anthropogenic sources), whereas the natural group comprised “forest,” “rangeland,”

or “reference” samples only 4 

# . These groups follow those de fined and recommended for use by

the EPA’s Framework for Inorganic Metals Risk Assessment (U.S. Environmental Protection

3 

# NAWQA sediment samples are sieved to <63 μm to promote the collection of fine-grained surficial

sediments, which are natural accumulators of trace elements.

4 

# The authors acknowledge th at while Pb samples collected from site s classified under these three land use categories will most closely reflect natural background conc entrations, atmospheric input of lead may be present.

# AX7-125 Table AX7-2.2.1. NAWQA Land Use Categories and

Natural/Ambient Classification

NAWQA Land Use Categories Classification

Agricultural Ambient

Commercial/Industrial Ambient

Cropland Ambient

Forest Ambient/Natural

Mining Ambient

Mixed Ambient

NA Ambient

Orchard/Vineyard Ambient

Other/Mixed Ambient

Pasture Ambient

Rangeland Ambient/Natural

Reference Ambient/Natural

Residential Ambient

Urban Ambient



# Agency, 2004b). Finally, in addition to the natu ral/ambient classification, tissue samples were

further divided into “whole organism” and “liver” groups.

All data were compiled in spreadsheets wher ein non-detect values we re converted to onehalf the detection limit and the total number of samp les, percentage of non- detect values (percent

censorship), minimum, maximum, median, mea n, standard deviation, and cumulative density

functions were calculated for each endpoint for both the natural and ambient groups.

As discussed below, some datasets were highly censored; however, deletion of non-detect data

has been shown to increase the relative error in th e mean to a greater extent than inclusion of

non-detects as 1⁄2 of the detection limit (Newma n et al., 1989); therefore means and other

statistics were calculated using the latter method for this analysis . Finally, since all data were

geo-referenced, a geographic information system (GIS; ArcGIS) was used to generate maps,

conduct spatial queries and analys es, and calculate statistics.

# AX7-126 Lead Distributions Generate d from the NAWQA Database

Natural versus Ambient Groups

There were four to eight times more ambient surface water (Table AX7-2.2.2) and bulk

sediment (Table AX7-2.2.3) samples in the compiled dataset than natural samples. This is most

likely a function of both the NAWQA program site selection process and the fact that sites

unaffected by human activities are extremely limite d. The spatial distributions of natural and

ambient surface water/sediment sites were fairly comparable, with natural samples located in

almost all of the same areas as ambient sample s except in the Midwest (Ohio, Illinois, Iowa, and

Michigan), where natural site s were not present (Figure AX7 -2.2.3). This exception may be

because these areas are dominated by agricu ltural and urban areas. The same spatial

distributions were observed for the natural and ambient liver and whole organism tissue

samples (Figure AX7-2.2.4 and Figure AX7-2.2.5).

Table AX7-2.2.2. Summary Statistics of Ambient and Natural Levels of

Dissolved Lead in Surface Water

Surface Water Dissolved Pb (μg/L)

Statistic Natural Ambient

% Censorship 87.91 85.66

N 430 3445

Minimum 0.04 0.04

Maximum 8.40 29.78

Mean 0.52 0.66

Standard Deviation 0.59 1.20

Median 0.50 0.50

90th Percentile 0.50 0.50

95th Percentile 0.50 1.10

96th Percentile 0.67 2.00

97th Percentile 1.00 2.34

98th Percentile 1.79 3.58

99th Percentile 2.48 5.44

# AX7-127 Table AX7-2.2.3. Summary Statistics of Ambien t and Natural Levels of Total Lead in
<63 μm Bulk Sediment

Bulk Sediment <63 um Total Lead (μg/g)

Statistic Natural Ambient

% Censorship 1.16 0.48

N 258 1466

Minimum 0.50 0.50

Maximum 12000 12000

Mean 109.07 120.11

Standard Deviation 786.74 672.41

Median 22.00 28.00

90th percentile 66.30 120.00

95th percentile 161.50 200.00



# Surface Water

The total number of surface water Pb sample s was 3,445; however these data were highly

censored with 85.66% of the ambient samples (2951/3445) and 87.91% of the natural samples

(378/430) below the detection limit 5 

# (Table AX7-2.2.2). Consequently, the majority of the

variability between these two datasets fell between the 95th and 100th (maximum) percentiles,

as was shown by the frequency distributions of the two groups deviating only at the upper and

lower tails with most of the overlapping data fa lling at 0.50 μg/L (one-hal f of the most common

detection limit, 1.0 μg/L; Figure AX7-2.2.6). As expected, due to the definitions of the natural

and ambient groups, the 95th and 100th percentile s were consistently higher for the ambient

samples than the natural samples. Similarly, the mean ambient Pb concentration (0.66 μg/L)

was higher than the mean natura l Pb concentration (0.52 μg/L). 6

5 

# The NAWQA dataset contains multiple detection limits for Pb in surface water that have decreased over
time. While the majority of data were analyzed with a detection limit of 1.0 μg/L (before 2000/2001), the most
recent samples were analyzed with either a 0.5, 0.2, 0.16, or 0.08 μg/L det ection limit (after 2000/2001), and some older samples (N = 20) were analyzed with a detection limit of 2.0 μg/L.

6 

# The same pattern was observed upon calculating the mean Pb concentra tions based on detect data only
(ambient mean = 1.66 μg/L, natural mean = 0.87 μg/L); however, as previously discussed, calculations included

non-detect data as 1⁄2 of the detection limit to reduce the relative error in the mean.

# AX7-128Figure AX7-2.2.3. Spatial distribution of natural and ambient surface water/sediment sites (Surface water: natural N = 430,ambient N = 3445; Sediment: natural N = 258, ambient N = 1466).

# AX7-129Figure AX7-2.2.4. Spatial distribution of natural and ambient liver tissue sample sites (Natural N = 83, Ambient N = 559).

# AX7-130Figure AX7-2.2.5. Spatial distribution ofnatural and ambient whole organism tissue sample sites (Natural N = 93,Ambient N = 332).

# AX7-131 Figure AX7-2.2.6. Frequency distribution of ambi ent and natural levels of surface water
dissolved lead (μg/L).

Due to the preponderance of non-detectable (ND) measurements, assessing national trends

in surface water-dissolved Pb concentrations was not possible. However, areas with elevated Pb

concentrations were identified by classifying the data with detect able Pb concentrations above

and below the 99th percentile. The 99th percent ile (versus the 95th perc entile) was chosen in

this instance to represen t extreme conditions given the small window of variability in the dataset.

By convention, the 95th percentile wa s used in subsequent analyses of this type. Areas with high

surface water Pb concentrations were observed in Washington, Idaho, Utah, Colorado, Arkansas,

and Missouri (Figure AX7-2.2.7). The maximum m easured Pb concentration was located in

Canyon Creek at Woodland Park, ID, a site classified as mining land use.

Sediment

There were approximately one-half of the number of surface water data available for

sediments (N = 1466). In contrast to the surface water data, however, very few sediment data

were below the detection lim it (7/1466 ambient ND, 3/258 natural ND; Table AX7-2.2.3).

As expected, the mean ambient Pb concentr ation was higher than the mean natural Pb

# AX7-132Figure AX7-2.2.7. Spatial distribution of dissolved lead insurface water (N = 3445).`

# AX7-133 concentration (120.11 and 109.07 μg/g, respectivel y). Similarly, the median ambient Pb

concentration was higher than the median natural Pb concentration (28.00 and 22.00 μg/g,

respectively) and the ambient 95th percentil e was higher than the natural 95th percentile

(200.00 and 161.50 μg/g, respectively). While th e natural and ambient surface water Pb

distributions differed only at the extremes, the natu ral sediment Pb percentil es were consistently

lower than the ambient percentiles throughout th e distributions (Figure AX7-2.2.8). Unlike the

surface water dataset, because the sediment data set was not heavily censored, assessing national

trends in sediment Pb concentrations was possibl e. The data were mapped and categorized into

the four quartiles of the fre quency distribution (Figure AX7-2.2.9) . The following observations

were made:

• Sediment Pb concentrations generally increa sed from west to east (the majority of sites along East Coast had Pb concentrations in the fourth quartile of the sediment Pb
concentration frequenc y distribution).

• Several “hot spots” of concen trated sites with elevated sediment Pb concentrations were apparent in various western states.

• Sediment Pb concentrations were genera lly lowest in the midwestern states
(the majority of sites in North Dakota, Nebraska, Minnesota, and Iowa had Pb

concentrations in the first or second quartile of sediment Pb concentration
frequency distribution).

As was seen with surface water Pb concentrations, the highest measured sediment Pb

concentrations were found in Idaho, Utah, a nd Colorado. Not surpri singly, of the top 10

sediment Pb concentrations recorded, 7 were meas ured at sites classified as mining land use.

Tissue

As was true for the surface water data, ther e were a high number of tissue samples below

the detection limit (47/93 natu ral whole organism ND, 130/332 ambient whole organism ND,

74/83 natural liver ND, 398/559 ambient liver ND; Table AX7-2.2.4). In general, more

non-censored data were available for whole orga nism samples than liver samples, and for

ambient sites than natural sites. As expected, fo r whole organism samples, the 95th percentile Pb

concentration measured at ambien t sites was higher than that m easured at natural sites (3.24 and

2.50 μg/g, respectively); however, Pb liver conc entration 95th percen tiles for ambient and

natural samples were very similar, with the natural 95th percentile actually higher than the

# AX7-134 Figure AX7-2.2.8. Frequency distribution of ambien t and natural levels of bulk sediment
<63 μm total Pb (μg/g).

ambient 95th percentile (1.26 and 1.06 μg/g, respectiv ely). In addition, as expected, the median

and mean Pb liver concentrations of ambien t samples (0.15 and 0.36 μg/g, respectively) were

higher than the median and mean Pb liver con centrations of natural samples (0.11 and 0.28 μg/g,

respectively). The same pattern was observed in the whole organism median and mean Pb

concentrations (ambient: me dian = 0.59, mean = 1.03; natural: median = 0.35, mean =

0.95 μg/g). In addition, the frequency distribut ions of the liver and whole organism Pb

concentrations followed the same trends, with the natural percenti les consistently lower than the

ambient percentiles throughout the distribut ions (Figure AX7-2.2.10 and Figure AX7-2.2.11).

These whole organism results were compared with findings from the 1984 U.S. Fish and

Wildlife Service (USFWS) National Contaminan t Biomonitoring Program (NCBP) (Schmitt and

Brumbaugh, 1990). As part of this program, 321 co mposite samples of 3 to 5 whole, adult fish

of a single species were collected from 109 river and Great Lake stations throughout the country.

Samples were analyzed for Pb concentrations (μg/g ww) and the geometric mean, maximum, and

85th percentile were calculated. Upon comparing these summary statistics with the equivalent

NAWQA ambient group value (NCBP stations were representative of both natural and

anthropogenically influenced conditions), a very strong agreement between the two analyses was

# AX7-135Figure AX7-2.2.9. Spatial distribution of totallead in bulk sediment <63 μm (N = 1466).

# AX7-136 Table AX7-2.2.4. Summary Statistics of Ambient and Natural Levels of Lead
in Whole Organism and Liver Tissues

Tissue Pb (μg/g dry weight)

Whole Organism Liver



# Statistic Natural Ambient Natural Ambient



# % Censorship 50.54 39.16 89.16 71.20

N 93 332 83 559

Minimum 0.08 0.08 0.01 0.01

Maximum 22.60 22.60 3.37 12.69

Mean 0.95 1.03 0.28 0.36

Standard Deviation 2.53 1.74 0.54 0.96

Median 0.35 0.59 0.11 0.15

90th percentile 1.40 2.27 0.37 0.59

95th percentile 2.50 3.24 1.26 1.06



# observed for each endpoint (Table AX7-2.2.5). For example, NCBP and NAWQA geometric

mean Pb concentrations were nearly identical (0.55 and 0.54 μg/g dw, respectively) and the

85th percentiles only differed by 0.5 μg Pb/g dw (NCBP, 1.10 and NAWQA, 1.60). The authors

acknowledge that a high degree of censorship is present in both of these datasets and no firm

conclusions can be drawn by comparing these means. The objective of this exercise was limited

to showing how the NAWQA data co mpare to other national datasets.

As was the case with surface water data, the high amount of non-detectable measurements

did not allow for a national assessm ent of spatial trends in Pb tissue concentrations. Instead,

areas with high Pb tissue concentr ations were identified by classi fying the data above and below

the 95th percentile. Similar to surface water and sediments, tissu e concentrations were found to

be elevated in Washington, Idaho, Utah, Colora do, Arkansas, and Missouri; however, several of

the highest measured Pb concentrations were al so found in study units in the southwestern and

# AX7-137 Figure AX7-2.2.10. Frequency distribution of ambi ent and natural levels of lead in liver
tissue (μg/g dry weight).

Figure AX7-2.2.11. Frequency distribution of ambien t and natural levels of lead in whole
organism tissue (μg/g dry weight).

# AX7-138 Table AX7-2.2.5. Comparison of NCBP and NAWQA Ambient Lead Levels
in Whole Organism Tissues

Whole Organism Lead Concentration (μg/g dry weight)



# Statistic NCBP 1 

# NAWQA

Geometric Mean 0.55 0.54

Maximum 24.40 22.60

85th Percentile 1.10 1.60

1 

# To convert between wet and dry weight, wet weig ht values were multiplied by a factor of five.



# southeastern states (Figure AX7-2.2.12 and Figur e AX7-2.2.13). As expected, the majority of

the samples with elevated Pb concentrations were taken from sites classified as urban,

commercial/industrial, or mining.

Input and Distribution of Lead in Other Aquatic Systems

Because the NAWQA database does not c over lakes or the sea where atmospheric

deposition of Pb is highly likely, the primary litera ture was searched for studies using ultra-clean

sampling/analytical techniques to characterize Pb concentrations in these environments. Lead

concentrations in lakes and oceans were generally found to be much lower than those measured

in the lotic waters assessed by NAWQA. Surface wa ter concentrations of dissolved Pb measured

in Hall Lake, Washington in 1990 ranged from 2.1 – 1015.3 ng/L (Balistrieri et al., 1994).

Nriagu et al. (1996) found that the average surfac e water dissolved Pb co ncentrations measured

in the Great Lakes (Superior, Erie, and On tario) between 1991 and 1993 were 3.2, 6.0, and

9.9 ng/L, respectively. Lead concentrations ra nged from 3.2 – 11 ng/L acro ss all three lakes.

Similarly, 101 surface water tota l Pb concentrations measured at the HOT station ALOHA

between 1998 and 2002 ranged from 25 – 57 pmol/kg (5 – 11 ng/kg; (Boyle et al., 2005). Based

on the fact that Pb is predominately found in the dissolved form in the open ocean (<90%;

Schaule and Patterson, 1981), dissolved Pb concen trations measured at these locations would

likely have been even lower than the total Pb concentrations reported.

# AX7-139Figure AX7-2.2.12. Spatial distribution oflead in liver tissues (N = 559).

# AX7-140Figure AX7-2.2.13. Spatial distribution of lead in wholeorganism tissues (N = 332).

# AX7-141 In open waters of the North Atlantic the declin e of Pb concentrations has been associated

with the phasing out of leaded gasoline in No rth America and western Europe (Véron et al.,

1998). Likewise, Pb restrictions in gasoline appear to have been effective in reducing

atmospheric Pb loading to the Okefenokee Swamp in southern Georgia/northern Florida

(Jackson et al., 2004). Based on se diment cores from the Okefenokee Swamp, Pb concentrations

were approximately 0.5 mg/kg prior to indus trial development, reached a maximum of

approximately 31 mg/kg from about 1935 to 1965, a nd following passage of the Clean Air Act in

1970 concentrations have declined to about 18 mg /kg in 1990 (Jackson et al., 2004). Trends in

metals concentrations (roughly 1970-2001) in sedime nt cores from 35 reservoirs and lakes in

urban and reference settings were analyzed by Mahl er et al. (2006) to determine the effects of

three decades of legislation, regulation, and chan ging demographics and industrial practices in

the United States on concentrations of metals in the environment. The researchers found that

decreasing trends outnumbered increasing trends for all seven metals analyzed (Cd, Cr, Cu, Pb,

Hg, Ni, and Zn). The most consistent trends we re for Pb and Cr: For Pb, 83% of the lakes had

decreasing trends and 6% had in creasing trends; for Cr, 54% of the lakes had decreasing trends

and none had increasing trends. Mass accumulati on rates of metals in cores, adjusted for

background concentrations, decreased from th e 1970s to the 1990s, where median changes

ranged from 246% (Pb) to 23% (Hg and Zn). Th e largest decreases were found in lakes located

in dense urban watersheds where the overall metals contamination in recently deposited

sediments decreased to on-half its 1970s median value. Howe ver, Mahler et al. (2006) found

that anthropogenic mass accumulation rates in dens e urban lakes remained elevated over those in

lakes in undeveloped watersheds, in some cases by as much as two orders of magnitude (Cr, Cu,

and Zn), indicating that urba n fluvial source signals can ov erwhelm those from regional

atmospheric sources. In estuarine systems, howev er, it appears that similar declines following

the phase-out of leaded gasoline are not necessarily as rapid. Steding et al. (2000) used isotopic

evidence to demonstrate the continued cycling of Pb in the San Francisco Bay estuary. In the

southern arm of San Francisco Bay, which has an average depth of <2 m, Steding et al. (2000)

found that isotopic compositions were essentially invariant, with 90% of the Pb derived from

1960s-1970s leaded gasoline. The authors attribut ed this to the limited hydraulic flushing and

remobilization of Pb from bottom sediments. In the northern arm of San Francisco Bay,

although seasonal and decadal variations in Pb isotope composition were observed, mass balance

# AX7-142 calculations indicate that only a small fraction of leaded gasoline fallout from the late 1980s has

been washed out of the San Joaquin and S acramento rivers’ drainage basin by 1995 and

consequently freshwater inputs remain a Pb sour ce to the bay (Steding et al., 2000). The authors

suggest that the continuous sour ce of Pb from the river system s draining into the bay, coupled

with benthic remobilization of Pb, indicates that historic gasoline deposi ts may remain in the

combined riparian/estuarine system for decades.

AX7.2.2.3 Tracing the Fate and Transpor t of Lead in Aquatic Ecosystems

The following section presents a generalized fram ework for the fate and transport of Pb in

aquatic systems (Figure AX7-2.2.14). The prim ary source of Pb in natural systems is

atmospheric deposition (Rickard and Nriagu, 197 8; U.S. Environmental Protection Agency,

1986a). Estimated median global atmospheric emission for anthropogenic and natural sources

are 332 Η 10 6 

# kg/year and 12 Η 10 6 

# kg/year, respectively (summa rized by Giusti et al., 1993).

Inorganic and metallic Pb compounds are nonvolatile and will partition to airborne particulates

or water vapors (Syracuse Res earch Corporation., 1999). Disper sion and deposition of Pb is

dependent on the particle size (U.S. Envi ronmental Protection Agency, 1986a; Syracuse

Research Corporation., 1999). More soluble form s of Pb will be removed from the atmosphere

by washout in rain.

In addition to atmospheric deposition, Pb may enter aquatic ecosystems through industrial

or municipal wastewater effluents, storm water runoff, er osion, or direct point source inputs

(e.g., Pb shot or accidental spills). Once in th e aquatic environment, Pb will partition between

the various compartments of the system (e.g., dissolved phase, solid phase, biota). The

movement of Pb between dissolved and particul ate forms is governed by factors such as pH,

sorption, and biotransformation (see Section AX7.2.2.1). Lead bound to organic matter will

settle to the bottom sediment layer, be assimilate d by aquatic organisms, or be resuspended in the

water column. The uptake, accumulation, and toxici ty of Pb in aquatic organisms from water

and sediments are influenced by various envi ronmental factors (e.g., pH, organic matter,

temperature, hardness, bioavailability). These factors are further described in Section

AX7.2.3.4). The remainder of this section di scusses some methods for describing the

distribution of atmospheric Pb in the aquatic environment.

# AX7-143 Figure AX7-2.2.14. Lead cycle in an aquatic ecosystem.

Sediment Core Dating and Source Tracing

In addition to directly measuring Pb concentr ations in various aqua tic compartments (see

Section AX7.2.3.3), it is useful to study the vertical distribution of Pb. Sediment profiling and

core dating is a method used to determine the extent of accumulation of atmospheric Pb and

provide information on potential anthropogenic sources. Sedime nt concentration profiles are

typically coupled with Pb is otopic analysis. The isotope fingerprinting method utilizes

measurements of the abundance of common Pb isotopes (i.e., 204 

# Pb, 206 

# Pb, 207 

# Pb, 208 

# Pb) to

distinguish between natural Pb over geologic time and potential anthropogenic sources. Details

of this method were described in Sec tion AX7.1.2. The concentration of isotope 204 

# Pb has

remained constant throughout time, while the ot her isotope species can be linked to various

anthropogenic Pb sources. Typically, th e ratios or signatures of isotopes (e.g., 207 

# Pb: 206 

# Pb) are

compared between environmental samples to indicate similarities or differences in the site being

investigated and the potential known sources.

Generally, Pb concentrations in sediment va ry with depth. For example, Chow et al.

(1973) examined sediment Pb profiles in southe rn California. Lead concentrations were

increased in the shallower sediment depths and co mparatively decreased at greater depths. These

changes in sediment vertical concentration were attributed to higher anthropogenic Pb fluxes

# AX7-144 from municipal sewage, storm runoff, and at mospheric deposition. Similar experiments

conducted throughout the United States have also s uggested an increase in Pb concentrations in

the upper sediment layer concomitant with in creases in anthropogenic inputs (Bloom and

Crecelius, 1987; Case et al., 1989; Rits on et al., 1999; Chillrud et al., 2003).

Sediment Pb concentration profiles and isotope analysis have also been used to identify

specific anthropogenic sources. For example, Flegal et al. (1987) used isotopic ratios to trace

sources of Pb in mussels from Monterey Bay, CA to a specific sl ag deposit. Several

investigators have examined isot opic tracers to determine potential regional sources of Pb in

eastern North America and the Great Lakes (Fle gal et al., 1989b; Graney et al., 1995; Blais,

1996). Water samples from Lake Erie and Lake Ontario were collected and analyzed. Lead

isotope ratios ( 206 

# Pb: 207 

# Pb) from the lakes were compared to known ratios for Pb aerosols derived

from industrial sources in Canada and the United States and found to corr elate positively. This

indicated that a majority of Pb in the lakes was derived from those industrial sources (Flegal

et al., 1989b). Similarly, Gallon et al. (2006) used 206 

# Pb: 207 

# Pb ratios in sediment cores collected

from a 300 km transect in Canadian Shield headwa ter lakes to differentiate Pb contributions from

smelter emissions relative to Pb contributions from other anthropogenic inputs. The authors

were able to estimate the amounts of smelter-der ived Pb in sediment collected along the 300 km

transect. Lead isotopes in sediment cores from Quebec and Ontario, Canada were also used to

distinguish between the amount of Pb deposited from local Canadian sources (28.4 to 61.7%)

and U.S. sources (38.3 to 71.6%) (Blais, 1996). Ex amination of Pb isotopes in sediment and

suspended sediment in the St. Lawrence River we re used to identify pot ential anthropogenic Pb

sources from Canada (Gobeil et al., 1995, 2005). Graney et al. (1995) used Pb isotope

measurements to describe the differing historic sources of Pb in Lake Erie, Ontario and in

Michigan. Temporal changes in Pb isotopic ratios were found to correspond to sources such as

regional deforestation from 1860 through1890, coal combustion and or smelting through 1930,

and the influence of leaded gaso line consumption from 1930 to 1980.

The historic record of atmospheric Pb pollu tion has been studied to understand the natural

background Pb concentration and the effects of Pb accumulation on ecosystems (Bindler et al.,

1999; Renberg et al., 2000, 2002; Brännvall et al., 2001a,b). The most extensive work in this

area has been conducted at pristine locations in Sw eden (Bindler et al., 1999). In this study, soil,

sediment, and tree rings were sampled for Pb concentrations and isotopic analyses were

# AX7-145 conducted on the soil samples. From this recor d, historic Pb concentrations and Pb accumulation

rates were estimated. Present da y concentrations in the forest soils ranged from 40 to 100 mg/kg,

while a natural background concentr ation was estimated at <1 mg/kg. The authors were able to

model Pb concentrations for the past 6,000 years and also to proj ect Pb concentrations for the

next 400 years, given an assumed atmos pheric deposition rate of 1 mg Pb m ! 2 

# /year. Models such

as this are useful tools in determining the critical limits of metals in soils or sediments (Bindler et

al., 1999; Renberg et al., 2002).

Lead source association may also be asse ssed through retrospective measurements.

Squire et al. (2002) used a time-se ries approach to evaluate the change in Pb in San Francisco

Bay, CA from 1989 to 1999. This approach involved the use of detailed linear regression models

and long-term monitoring data to determine change s in Pb concentrations and to identify events

corresponding to those changes. Sediment and water samples were collected throughout the bay

and combined with data on effluent discharges, urban runoff, atmospheric deposition, and river

discharges. The authors identifi ed a 40% decline of Pb in the southern portion of the bay but

found no change in the northern re ach. The decline was attributed to a reduction in wastewater

source loadings over the previous decade.

AX7.2.2.4 Summary

Lead is widely distributed in aquatic ecosystems, pre dominantly originating from

atmospheric deposition or point source contribution. The fate and behavior of Pb in aquatic

systems is regulated by physical and chemical f actors such as pH, salinity, sediment sorption,

transformation, and uptake by aquatic biota. In th e United States, Pb concentrations in surface

waters, sediments, and fish tissues range fr om 0.04 to 30 μg/L, 0.5 to 12,000 mg/kg, and 0.08 to

23 mg/kg, respectively. Atmospheri c sources are generally decreasi ng, as the United States has

removed Pb from gasoline and other products. Howe ver, elevated Pb conc entrations remain at

sites associated with mining wastes or wastewat er effluents. Since the 1986 Lead AQCD, much

has been learned about the proces ses affecting Pb fate and tran sport. Detailed analyses are

currently available (i.e., Pb isotope dating) to allow for constructi ng the history of Pb

accumulation and identifying specific Pb contam inant sources. Continued source control along

with examination of the physical and chemical properties will further a llow for the reduction of

Pb concentrations throughout the United States.

# AX7-146 

# AX7.2.3 Aquatic Species Response/Mode of Action

Recent advancements in understanding the resp onses of aquatic biota to Pb exposure are

highlighted in this section. A summary of the co nclusions on the review of aquatic responses to

Pb from the appropriate sections of the 1986 Lead AQCD, Volume II (U.S. Environmental

Protection Agency, 1986a) and the subsequent co nclusions and recommen dations contained in

the EPA staff review of that document (U.S. Environmental Protection Agency, 1990) are also

provided. In addition, this sec tion summarizes research subs equent to the 1986 Lead AQCD on

Pb uptake into aquatic biota, effects of Pb sp eciation on uptake, resistance mechanisms to Pb

toxicity, physiological eff ects of Pb, factors that affect res ponses to Pb, and factors associated

with global climate change. Areas of research that are not addr essed here include literature

related to exposure to Pb shot or pellets and studies that exam ine human health-related endpoints

(e.g., hypertension), which are described in other sections of this document.

AX7.2.3.1 Lead Uptake

Lead is nutritionally nonessentia l and non-beneficial and is toxi c to living organisms in all

of its forms (Eisler, 2000). Lead can bioaccumu late in the tissues of aquatic organisms through

ingestion of food and water and adsorption fr om water (Vázquez et al., 1999; Vink, 2002) and

subsequently lead to adverse effects if tissue levels are sufficiently high (see Section AX7.2.5).

Recent research has suggested that due to the low so lubility of Pb in water, dietary Pb (i.e., lead

adsorbed to sediment, particulate matter, and f ood) may contribute substan tially to exposure and

toxicity in aquatic biota (B esser et al., 2005). Besser et al. (2004) exposed the amphipod

Hyalella azteca to concentrations of Pb to evaluate th e influence of waterborne and dietary Pb

exposure on acute and chronic toxi city. The authors found that acu te toxicity was unaffected by

dietary exposure but that diet ary Pb exposure did contribute to chronic toxic effects (i.e.,

survival, growth, reproduction) in H. azteca . Field studies in ar eas affected by metal

contamination (i.e., Clark Fork River, MO; Coeur d’Alene, ID) (Woodward et al., 1994, 1995;

Farag et al., 1994) have also de monstrated the effects of diet ary metals on rainbow trout.

However, there has been a debate on the impor tance of dietary exposure, as few controlled

laboratory studies have been able to replicate the effects observed in the field studies (Hodson

et al., 1978; Mount, 1994; Erikson, 2001) . This may be due to differe nces in the availability of

Pb from the dietary sources used in laborat ory studies, differences in speciation, and/or

# AX7-147 nutritional characteristics of the Pb dosed diets. In many fiel d and laboratory studies, dietary

exposure is rarily considered, but food provided to biota in these studie s adsorb metals from

water. Therefore, both dietary and waterb orne exposure are occurring and both may be

considered to play roles in eliciting the measured effects.

Lead concentrations in the ti ssues of aquatic organisms are generally higher in algae and

benthic organisms and lower in higher trophic-level consumers (Eisler, 2000). Thus, trophic

transfer of Pb through food chains is not expected (Eisler, 2000) . Metals are not metabolized;

therefore, they are good integrat ive indicators of exposure in a quatic biota (Luoma and Rainbow,

2005). Metal uptake is complex, being influenced by geochemistry, route of exposure (diet and

adsorption), depuration, and grow th (Luoma and Rainbow, 2005). This section discusses the

factors affecting uptake of Pb by aq uatic biota and the state of current research in this area.

As described in Section AX7.2.2.1, the solubili ty of Pb in water varies with pH,

temperature, and ion concentra tion (water hardness) (Weber, 1993). Lead becomes soluble and

bioavailable under conditions of low pH, or ganic carbon content, suspended sediment

concentrations, and ionic concentrations (i.e., low Cd, Ca, Fe, Mn, Zn) (Eisler, 2000). Lead

rapidly loses solubility above pH 6.5 (Rickard and Nriagu, 1978) and preci pitates out as Pb(OH) +



# and PbHCO 3 + 

# into bed sediments. However, at redu ced pH levels or ionic concentrations,

sediment Pb can remobilize and potentially beco me bioavailable to aquatic organisms (Weber,

1993).

The most bioavailable inorganic fo rm of Pb is divalent Pb (Pb 2+ 

# ), which tends to be more

readily assimilated by organisms than complexed forms (Erten-Unal et al., 1998). On the other

hand, the low solubility of Pb salts restricts mo vement across cell membranes, resulting in less

accumulation of Pb in fish in comparison to other metals (e.g., Hg, Cu) (Baatrup, 1991).

The accumulation of Pb in aquatic organisms is , therefore, influenced by water pH, with

lower pHs favoring bioavailability and accumulati on. For example, fish accumulated Pb at a

greater rate in acidic lakes (pH = 4.9 to 5.4) than in more neutral lakes (pH = 5.8 to 6.8) (Stripp

et al., 1990). Merlini and Pozzi (1977) found that pumpkinseed sunfish exposed to Pb at pH 6.0

accumulated three-times as much Pb as fish ke pt at pH 7.5. However, Albers and Camardese

(1993a,b) examined the effects of pH on Pb uptake in aquatic plan ts and invertebrates in acidic

(pH ~5.0) and nonacidic (pH ~6.5) constructed wetlands, ponds, and small lakes in Maine and

Maryland. Their results suggested that low pH had little effect on the accumulation of metals by

# AX7-148 aquatic plants and insects and on the concentratio n of metals in the waters of these aquatic

systems (Albers and Camardese, 1993a,b).

Three geochemical factors that influence metal bioaccumulation in aquatic organisms

include speciation, particulate metal form, and metal form in the tissues of prey items (Luoma

and Rainbow, 2005). Lead is typically pres ent in acidic aquatic environments as PbSO 4 

# , PbCl 4 

# , ionic Pb, cationic forms of Pb-hydr oxide, and ordinary hydroxide Pb(OH) 2 

# . In alkaline waters,

common species of Pb include ani onic forms of Pb-carbonate (Pb(CO 3 

# )) and Pb(OH) 2 

# . Labile

forms of Pb (e.g., Pb 2+ 

# , PbOH + 

# , PbCO 3 

# ) are a significant portion of the Pb inputs to aquatic

systems from atmospheric washout. Particul ate-bound forms are more often linked to urban

runoff and mining effluents (Eisle r, 2000). Little research has been done to link the complex

concepts of chemical speciation and bioavail ability in natural systems (Vink, 2002). The

relationship between the geochemistry of the unde rlying sediment and the impact of temporal

changes (e.g., seasonal temperatures) to metal sp eciation are particularly not well studied (Vink,

2002; Hassler et al., 2004).

Generally speaking, aquatic organisms exhi bit three Pb accumulation strategies:

(1) accumulation of significant Pb concentrations with a low rate of loss, (2) excretion of Pb

roughly in balance with availabil ity of metal in the environment, and (3) weak net accumulation

due to very low metal uptake rate and no signi ficant excretion (Rainbow, 1996). Species that

accumulate nonessential metals such as Pb and th at have low rates of loss must partition it

internally in such a way that it is sparingly available metabol ically. Otherwise, it may cause

adverse toxicological effects (R ainbow, 1996). Aquatic organisms that exhibit this type of

physiological response have been recommended fo r use both as environmental indicators of

heavy metal pollution (Borgmann et al., 1993; Cast ro et al., 1996; Carter and Porter, 1997) and,

in the case of macrophytes, as phytoremediators, because they accumulate heavy metals rapidly

from surface water and sediment (Gavrilenko an d Zolotukhina, 1989; Simòes Gonçalves et al.,

1991; Carter and Porter, 1997).

Uptake experiments with aquatic plan ts and invertebrates (e.g., macrophytes,

chironomids, crayfish) have shown steady in creases in Pb uptake with increasing Pb

concentration in solution (Knowlton et al., 1983 ; Timmermans et al., 1992). In crayfish, the

process of molting can cause a redu ction in body Pb concentrations, as Pb incorporated into the

crayfish shell is eliminated (K nowlton et al., 1983). Vázquez et al. (1999) reported on the uptake

# AX7-149 of Pb from solution to the extr acellular and intracellular compartm ents of 3 species of aquatic

bryophytes. Relative to the 6 metals tested, Pb wa s found to accumulate to the largest degree in

the extracellular compartments of all 3 bryophytes . The extracellular metals were defined as

those that are incorporated into the cell wall or are found on the outer surface of the plasma

membrane (i.e., adsorbed) (Vázquez et al., 1999). Intracellular me tals were defined as metals

introduced into the cell through a meta bolically controlled process.

Arai et al. (2002) examined the effect of growth on the uptake and elimination of trace

metals in the abalone Haliotos . They reported that older abal ones had generally lower whole

body concentrations of heavy metals than did you nger, rapidly growing individuals. During the

rapid growth of juveniles, the organism is less able to distinguish between essential (e.g., Zn),

and nonessential metals (e.g., Pb). Once they re ach maturity, they develop the ability to

differentiate these metals. Li et al. (2004) reported a similar response in zebra fish embryolarvae. Li et al. (2004) suggest ed that mature physiological sy stems are not developed in the

embryo-larvae to handle elevated concentrations of metals. Therefore, metals are transported

into the body by facilitated diffusion. Both the zebra fish and juvenile abalone demonstrate a

rapid accumulation strategy followed by a low ra te of loss as described above. There are

insufficient data available to determine whet her this phenomenon is true for other aquatic

organisms.

Growth rates are generally thought to be an important consideration in the comparison of

Pb levels in individuals of the same species. The larger the indi vidual the more the metal content

is diluted by body ti ssue (Rainbow, 1996).

Once Pb is absorbed, it may sequester into varying parts of the organism. Calcium

appears to have an important influence on Pb tran sfer. For example, Pb uptake and retention in

the skin and skeleton of coho salmon was reduced when dietary Ca was increased (Varanasi and

Gmur, 1978). Organic Pb compounds tend to accumulate in lipids, and are taken up and

accumulated in fish more readily than inorganic Pb compounds (Pattee and Pain, 2003).

Given the complexities of metal uptake in natu ral systems, a model incorporating some of

the factors mentioned above is desirable. Th e EPA’s Environmental Re search Laboratory in

Duluth, Minnesota developed a thermodynamic e quilibrium model, MINTEQ that predicts

aqueous speciation, adsorption, precipitation, and/or dissolution of solids for a defined set of

environmental conditions (MacDonald et al., 2002; Playle, 2004). Although not specifically

# AX7-150 designed to model uptake, MINTEQ provides an indication of what forms of the metal are likely

to be encountered by aquatic organisms by estima ting the formation of metal ions, complexation

of metals, and the general bioa vailability of metals from environmental parameters. More

recently, a mechanistic model centered on bi odynamics has been proposed by Luoma and

Rainbow (2005) as a method of tying together geochemical influences, biological differences,

and differences among metals to model metal bioaccumulation. The biodynamic model would

be useful in determining the pot ential adverse effects on aquatic biota, which species are most

useful as indicators of metal effects, and how ecosystems may change when contaminated by

metals. Two prominent models examine trace me tal bioavailability and its link to effects

(Hassler et al., 2004). These include the free i on activity model (FIAM) and the biotic ligand

model (BLM). Specific information on these mode ls, including their lim itations, is provided in

Section AX7.2.1.3. These models are useful fo r advancing our understanding of how metal

uptake occurs in aquatic organisms and how uptake and toxic effects are linked.

Bioconcentration Factors (BCF)

BCFs for Pb are reported for va rious aquatic plants in Ta ble AX7-2.3.1. The green alga

Cladophora glomerata is reported as having the highest BCF (Keeney et al., 1976). Duckweed

( Lemna minor ) exhibited high BCF values ranging from 840 to 3560 depending on the method of

measurement (Rahmani and Sternberg, 1999). Duckw eed that was either previously exposed or

not exposed to Pb was exposed to a single dos e of Pb-nitrate at 5000 μg/L for 21 days.

Duckweed that was previously exposed to Pb removed 70 to 80% of the Pb from the water, while

the previously unexposed duckweed removed 85 to 90%. Both plant groups were effective at

removing Pb from the water at sublethal levels.

BCFs for Pb are reported for various i nvertebrates in Table AX7-2.3.2. BCFs for

freshwater snails were 738 for a 28-day e xposure (Spehar et al., 1978) and 1,700 for a 120-day

exposure (Borgmann et al., 1978). Other reported values for invertebrates included a BCF of

1930 for the scud during a 4-day exposure (MacL ean et al., 1996), and BCF s of 499 and 1120 for

the caddis fly and stonefly, respectively, in 28-d ay exposures (Spehar et al., 1978). In a 28-day

exposure, midge larvae were reported with a BCF of 3670 (Timme rmans et al., 1992).

# AX7-151 Table AX7-2.3.1. Bioconcentration Factors for Aquatic Plants

BCF Species Test Conditions Reference



# 840 to 2700 (measured digestion) Duckweed
( Lemna minor ) 21 days, Pb-nitrate Rahmani and Sternberg
(1999)

1150 to 3560
(measured solution) Duckweed 21 days, Pb-nitrate Rahmani and Sternberg
(1999)

16,000 to 20,000 Alga (Cladophora
glomerata ) not specified Keeney et al. (1976)



# Table AX7-2.3.2. Bioconcentration Fact ors for Aquatic Invertebrates

BCF Species Test Conditions Reference



# 738 Snail ( Physa integra ) 28 days, Pb-nitrate Spehar et al. (1978)

1700 Snail ( Lymnaea palustris ) 120 days, Pb-nitrate Borgmann et al. (1978)

499 Caddis fly ( Brachycentrus sp. ) 28 days, Pb-nitrate Spehar et al. (1978)

1120 Stonefly ( Pteronarcys dorsata ) 28 days, Pb-nitrate Spehar et al. (1978)

1930 Scud ( Hyalella azteca ) 4 days, Pb-chloride MacLean et al. (1996)

3670 Midge larvae ( Chironomus riparius ) 28 days Timmermans et al. (1992)



# BCFs for freshwater fish were 42 and 45 for brook trout and bluegill, respectively

(Holcombe et al., 1976; Atchis on et al., 1977). Although no BCFs have been reported for

amphibians, Pb-nitrate was reported to accumulate ma inly in the ventral skin and in the kidneys

of frogs (Vogiatzis and Loumbourdis, 1999).

Bioconcentration factors and bioaccumulation fa ctors (BAFs) are not necessarily the best

predictors of tissue concentration levels given exposure concentration levels (Kapustka et al.,

2004). The role of homeostatic mechanisms is a major consideration in tissue concentrations

found in exposed biota. Similarly, measuring BC Fs and BAFs in organisms may not accurately

reflect how metals are treated within the orga nisms (e.g., partitioning to specific organelles,

# AX7-152 sequestering to organ tissues). Therefore, they are not recommended for use in conducting metal

risk assessments (Kapustka et al., 2004).

AX7.2.3.2 Resistance Mechanisms

Detoxification Mechanisms

Detoxification includes the biological proces ses by which the toxic qualities, or the

probability and/or severity of harmful effects, of a poison or toxin are reduced by the organism.

In the case of heavy metals, this process fre quently involves the sequestration of the metal,

rendering it metabolically inactive. Recent resear ch into heavy metal detoxification in aquatic

biota has focused on several phys iological and biochemical mechanisms for detoxifying Pb.

This section examines these mechanisms and the abil ity of plants, protists, invertebrates, and fish

to mitigate Pb toxicity.

Plants and Protists

Deng et al. (2004) studied the uptake and tran slocation of Pb in wetland plant species

surviving in contaminated sites. They found that all plants tended to sequester significantly

larger amounts of Pb in their roots than in their shoots. Deng et al. (2004) calculated a

translocation factor (TF), the am ount of Pb found in the shoots divided by the amount of Pb

found in the root system, and found that TFs ranged from 0.02 to 0.80. Concentrations of Pb in

shoots were maintained at low levels and vari ed within a narrow ra nge. Deng et al. (2004)

observed that plants grown in Pb-contaminated sites usually contained higher concentrations

than the 27 mg/kg toxicity threshold established for plants by Beckett a nd Davis (1977). Some

of the wetland plants examined by Deng et al. (2004) also accumu lated high concentrations of

metals in shoot tissues; however, these metals were assumed to be detoxified (metabolically

unavailable), as no toxic response to these elevated concentrations was observed. Deng et al.

(2004) suggested that this ability is likely related to discrete internal metal detoxification

tolerance mechanisms.

Phytochelatins are thiol-cont aining intracellular metal-bi nding polypeptides that are

produced by plants and protists in response to excessive uptake of heavy metals (Zenk, 1996).

Phytochelatins are synthesized by the enzyme ph ytochelatin synthase th at is activated by the

presence of metal ions and uses glutathione as a substrate. When phytoc helatins are synthesized

# AX7-153 in sufficient amounts to chelate the metal ion, th e enzyme is deactivated (Morelli and Scarano,

2001).

Morelli and Scarano (2001) studied phytochela tin synthesis and stability in the marine

diatom Phaeodactylum tricornutum in the presence of Pb. They found that when metal exposure

was alleviated, significant cellular Pb-phytochela tin complex content was lost. Their findings

support a hypothesis of vacuolar ization proposed for higher plan ts (Zenk, 1996), in which metalphytochelatin complexes are activel y transported from the cytosol to the vacuole, where they

undergo rapid turnover. Zenk (1996) suggested that the complex dissociates, and the metal-free

peptide is subsequently degraded. Morelli a nd Scarano (2001) proposed concomitant occurrence

of phytochelatin synthesis and release during me tal exposure, as a coincident detoxification

mechanism in P. tricornutum

.

Aquatic Invertebrates

Like plants and protists, aquatic animal s detoxify Pb by preventing it from being

metabolically available, though their mechanis ms for doing so vary. Invertebrates use

lysosomal-vacuolar systems to sequester and pro cess Pb within glandular cells (Giamberini and

Pihan, 1996). They also accumulate Pb as de posits on and within skeletal tissue (Knowlton

et al., 1983; Anderson et al., 1997; Boisson et al., 2002), and some can efficiently excrete Pb

(Vogt and Quinitio, 1994; Prasuna et al., 1996).

Boisson et al. (2002) used radiot racers to evaluate the transfer of Pb into the food pathway

of the starfish Asterias rubens as well as its distributi on and retention in various body

compartments. Boisson et al. (2002) monitored Pb elimination after a single feeding of Pbcontaminated molluscs and found that Pb was sequ estered and retained in the skeleton of the

starfish, preventing it from being metabolically available in other tissues. Elimination (as

percent retention in the skeleton) was found to follow an exponential time course. Elimination

was rapid at first, but slowed after 1 week, and eventually stabilized, implying an infinite

biological half-life for firmly bound Pb. Results of radiotracer tracking sugge st that Pb migrates

within the body wall from the organic matrix to th e calcified skeleton. From there, the metal is

either absorbed directly or adsorbed on newl y produced ossicles (small calcareous skeletal

structures), where it is efficiently retained as mineral deposition and is not metabolically active

(Boisson et al., 2002).

# AX7-154 AbdAllah and Moustafa (2002) studied the Pb st orage capability of organs in the marine

snail Nerita saxtilis . Enlarged electron-dense vesicles and many granules were observed in

digestive cells of these snails a nd are suggested to be the site of storage of detoxified metals.

N. saxtilis were found to be capable of concentrat ing Pb up to 50 times that of surrounding

marine water without exhibiting signs of histopathologic change s. This ability has been

attributed to chelation with various bioc hemical compounds, such as thionine (forming

metallothionine) (Rainbow, 1996), or complexation with carbonate, forming lipofuchsin

(AbdAllah and Moustafa, 2002). Granules observed in lysosomal residual bodies were presumed

to be the result of Pb accumulation. The presen ce of large vacuoles and residual bodies were

indicative of the fragmentation phase of diges tion, suggesting that Pb was also processed

chemically in the digestive cells.

The podocyte cells of the pericardial gland of biva lves are involved in the ultrafiltration of

the hemolymph (Giamberini and Pihan, 1996). A microanalytical study of the podocytes in

Dreissena polymorpha exposed to Pb revealed lysosomal-v acuolar storage/processing similar to

that in the digestive cells of Nerita saxtilis. The lysosome is thought to be the target organelle

for trace metal accumulation in various organs of bivalves (Giamberini and Pihan, 1996).

Epithelial secretion is the principal det oxification mechanism of the tiger prawn Penaeus

monodon . Vogt and Quinitio (1994) found that Pb granules tended to accumulate in the

epithelial cells of the an tennal gland (the organ of excretio n) of juveniles exposed for 5 and

10 days to waterborne Pb. The metal is depos ited in vacuoles belonging to the lysosomal

system. Continued deposition leads to the fo rmation of electron-dens e granules. Mature

granules are released from the cells by apocrine secretion in to the lumen of the gland, and

presumably excreted through the nephridopore (i .e., the opening of the antennal gland).

Apocrine secretion is predominant, so that as granules form, they are kept at low levels.

Excretion was also found to be a primary and e fficient detoxification mechanism in the shrimp

Chrissia halyi (Prasuna et al., 1996).

Crayfish exposed to Pb have been shown to concentrate the metal in their exoskeleton and

exuvia through adsorption processes. More than 80% of Pb found in exposed crayfish has been

found in exoskeletons (Knowlton et al., 1983; A nderson et al., 1997). Following exposure,

clearance is most dramatic from the exoskeleton. The result of a 3-week Pb-clearance study with

red swamp crayfish Procambarus clarkia , following a 7-week exposure to 150 μg Pb/L, showed

# AX7-155 an 87% clearance from the exoskeleton due, in part , to molting. Other organs or tissues that take

up significant amounts of Pb include the gills , hepatopancreas, muscle, and hemolymph, in

decreasing order. These parts cleared >50% of accumulated Pb over the 3-week clearance

period, with the exception of the hepatopancreas. The hepato pancreas is the organ of metal

storage and detoxification, although the molecular mechanisms of me tal balance in crayfish have

yet to be extensively inves tigated (Anderson et al., 1997).

Fish

Most fish use mucus as a first line of de fense against heavy metals (Coello and Khan,

1996). In fish, some epithelia are covered with extracellular mucus secreted from specialized

cells. Mucus contains glyc oproteins, and composition varies among species. Mucosal

glycoproteins chelate Pb, and se ttle, removing the metal from the water column. Fish may

secrete large amounts of mucus when they come into contact with pot ential chemical and

biochemical threats. Coello and Khan (1996) in vestigated the role of externally added fish

mucus and scales in accumulating Pb from water, and the relationship of th ese with the toxicity

of Pb in fingerlings of green sunfish, goldfish and largemouth bass. The authors compared trials

in which fish scales from black sea bass ( Centropristis striata ) and flounder ( Pseudopleuronectes

americanus ) and mucus from largemouth bass were added to green sunfish, goldfish, and

largemouth bass test systems and to reference test systems. On exposure to Pb, fish immediately

started secreting mucus from epidermal cells in va rious parts of the body. Metallic Pb stimulated

filamentous secretion, mostly from the ventrolatera l areas of the gills, while Pb-nitrate stimulated

diffuse molecular mucus secretion from all over the body. The addition of largemouth bass

mucus significantly increased the LT 50 

# (the time to kill 50%) for green sunfish and goldfish

exposed to 250 mg/L of Pb-nitrate. In contrast, Tao et al . (2000) found that mucus reduced the

overall bioavailability of Pb to fish but that the reduction was insignificant. Coello and Khan

(1996) found that scales were more significant in reducing LT 50 

# than mucous. Fish scales can

accumulate high concentrations of metals, includi ng Pb, through chelation with keratin. Scales

were shown to buffer the pH of Pb-nitrate in solu tion and remove Pb from water after which they

settled out of the water column. Addition of scales to test water made a ll species (green sunfish,

goldfish, and largemouth bass) more tolerant of Pb.

# AX7-156 Summary of Detoxifiction Processes

Mechanisms of detoxification vary among aqua tic biota and include processes such as

translocation, excretion, chelation, adsorption, vacuolar storage, and deposition. Lead

detoxification has not been studied extensively in aquatic organism s, but existing results indicate

the following:

• Protists and plants produce intr acellular polypeptides that fo rm complexes with Pb (Zenk,
1996; Morelli and Scarano, 2001).

• Macrophytes and wetland plants that thrive in Pb-contaminated regions have developed translocation strategies for tolerance and detoxification (K nowlton et al., 1983; Deng et al.,
2004).

• Some starfish (asteroids) se quester the metal via mineral deposition into the exoskeleton
(Boisson et al., 2002).

• Species of mollusc employ lysosomal-vacuolar sy stems that store and chemically process Pb in the cells of their digestive and pericardial glands (Giamberini and Pihan, 1996; AbdAllah
and Moustafa, 2002).

• Decapods can efficiently excrete Pb (Vogt a nd Quinitio, 1994; Giamberini and Pihan, 1996)
and sequester metal through adsorption to the exoskeleton (Knowlton et al., 1983).

• Fish scales and mucous chelate Pb in the water column, and potentially reduce visceral

exposure.

Avoidance Response

Avoidance is the evasion of a perceived threat. Recent research into heavy metal

avoidance in aquatic organisms has looked at dose-re sponse relationships as well as the effects of

coincident environmental factors. Preference/avoidance response to Pb has not been extensively

studied in aquatic organisms. In particular , data for aquatic invertebrates is lacking.

Using recent literature, this section exam ines preference-avoidance responses of

invertebrates and fish to Pb and some other environmental gradients.

Aquatic Invertebrates

Only one study was identified on avoidance re sponse in aquatic invertebrates. Lefcort

et al. (2004) studied the avoidance behavior of the aquatic pulmonate snail Physella columbiana

from a pond that had been polluted with heavy me tals for over 120 years. In a Y-maze test, first

generation P. columbiana from the contaminated site avoided Pb at 9283 μg/L (p < 0.05) and

# AX7-157 moved toward Pb at 6255 μg/L (p < 0.05). It is thought that attraction to Pb at certain elevated

concentrations is related to Pb neuron-stimulating properties (Lef cort et al., 2004). These results

are consistent with those from si milar studies. Control snails fr om reference sites, and first and

second-generation snails from contaminated site s were capable of detecting and avoiding heavy

metals, although the first genera tion was better than the second generation, and the second was

better than the controls at doing so. This sugge sts that detection and avoidance of Pb is both

genetic and environmentally based for P. columbiana. Lefcort et al. (2004) observed heightened

sensitivity to, and avoidance of, heavy metals by the snails when metals where present in

combination.

Aquatic Vertebrates

Steele et al. (1989) studie d the preference-avoidan ce response of bullfrog ( Rana

catesbeiana ) to plumes of Pb-contaminated water following 144-h exposure to 0 to 1000 μg

Pb/L. In this laboratory experi ment, tadpoles were exposed to an influx of 1000 μg Pb/L at five

different infusion rates (i.e., volumes per unit tim e into the test system). Experiments were

videotaped and location data from the tank were used to assess respons e. No significant

differences were seen in pref erence-avoidance responses to Pb in either nonexposed or

previously exposed animals. In a similar subsequent st udy, Steele et al. (1991) studied

preference-avoidance response to Pb in American toad ( Bufo americanus ) using the same

exposure range (0 to 1000 μg Pb/L). B. americanus did not significantly avoid Pb, and

behavioral stress responses were not observed. The results do not indicate whether the tadpoles

were capable of perceiving the contaminant. Lack of avoidance may indicate insufficient

perception or the lack of physiolo gical stress (Steele et al., 1991).

The olfactory system in fish is involved in their forming avoidance response to heavy

metals (Brown et al., 1982; Svecevi č ius, 1991). It is generally t hought that behavi oral avoidance

of contaminants may be a cause of reduced fi sh populations in some water bodies, because of

disturbances in migration and distribution patterns (Svecevi č ius, 2001). Unfortunately,

avoidance of Pb by fish has not been studied as extensively as for other heavy metals

(Woodward et al., 1995).

Woodward et al. (1995) studi ed metal mixture avoidan ce response in brown trout

( Salmo trutta ), as well as the added effect s of acidification. A 1-fold (1 Η ) mixture contained

# AX7-158 1.1 μg/L Cd, 12 μg/L Cu, 55 μg/L Zn, and 3.2 μg/L Pb (all metals were in the form of chlorides).

Avoidance was quantified as time spen t in test water, trip time to te st water, and number of trips.

Brown trout avoided the 1 Η mixture as well as the 0.5 Η , 2 Η , 4 Η , and 10 Η mixtures, but not the

0.1 Η mixture. Reduced avoidance was observed at higher concentrations (4 Η and 10 Η ). The

authors proposed that the reduced avoidance re sponse was due to impaired perception due to

injury. These responses are typical of other fish species to individual metals of similar

concentrations (Woodward et al., 1995). This st udy does not conclusively indicate which of the

metals in the mixture may be causing the avoi dance response. Howeve r, given the neurotoxic

effects of Pb, impaired perception is a likely response of Pb-exposed fish.

When test water was reduced in pH from 8 to 7, 6 to 5, brown trout avoidance increased,

but with no significant difference between metal treatments and controls. However, in the 1 Η

metal mixture treatment, brown trout made fewer tr ips into the test water chamber at the lower

pHs (Woodward et al., 1995). This response may be related to an increased abundance of Pb

cations at lower pH values in the test system.

Scherer and McNicol (1998) investigated th e preference-avoidance responses of lake

whitefish ( Coregonus clupeaformis ) to overlapping gradients of li ght and Pb. Whitefish were

found to prefer shade in untreated water. Lead concentrations under illumination ranged from

0 to 1000 μg/L, and from 0 to 54,000 μg/L in the shade. Under uniform illumination, Pb was

avoided at concentrations above 10 μg/L, but avoidance behavior l acked a dose-dependent

increase over concentrations ranging from 10 to 1000 μg Pb/L. Avoidance in shaded areas was

strongly suppressed, and whitefish only avoided Pb at concentra tions at or above 32,000 μg/L.

Summary of Avoidance Response

In summary, of those aquatic organisms studied, some are quite adept at avoiding Pb in

aquatic systems, while others seem incapable of detecting its presence. Snails have been shown

to be sensitive to Pb and to avoid it at high c oncentrations. Conversely, anuran (frog and toad)

species lack an avoidance response to the metal. Fish avoidance of many chemical toxicants has

been well established, and it is a dominant subl ethal response in po lluted waters (Svecevi č ius,

2001). However, no studies have been located sp ecifically examining avoidance behavior for Pb

in fish. Environmental gradients, such as light and pH, can alter preference-avoidance responses.

# AX7-159 AX7.2.3.3 Physiological Effects of Lead

This section presents a review of the physiological effects and functional growth

responses associated with the exposure of aquati c biota to Pb. Physiological effects of Pb on

aquatic biota can occur at the biochemical, cellula r, and tissue levels of organization and include

inhibition of heme formation, adverse effects to blood chemistry, and decreases in enzyme

levels. Functional growth responses resulting from Pb exposure include changes in growth

patterns, gill binding affiniti es, and absorption rates.

Biochemical Effects

Lead was observed to have a gender-selec tive effect on brain endocannabinoid (eCB)

(e.g., 2-arachidonylglyc erol [2-AG] and N -arachidonylethanolamine [AEA]) levels in fathead

minnow Pimephales promelas (Rademacher et al., 2005). Cannabi noids, such as eCB, influence

locomotor activity in organisms. Increased levels of cannabinoids have been shown to stimulate

locomotor activity and decreased levels slow locomotor activity (Sa ñudo-Peña et al., 2000).

Male and female fathead minnows were exposed to 0 and 1000 μg/L of Pb. Female minnows in

the control group contained signifi cantly higher levels of AEA and 2-AG compared to males.

At a concentration of 1000 μg Pb/L, this patte rn reversed, with males showing significantly

higher levels of AEA in the brain than fema les (Rademacher et al., 2005). After 14-days

exposure to the 1000 μg Pb/L trea tment, significantly higher levels of 2-AG were found in male

fathead minnows, but no effect on 2-AG levels in females was observed (Rademacher et al.,

2005).

Lead acetate slightly inhibited 7-ethoxyresorufin- o -deethylase (7-EROD) activity in

Gammarus pulex exposed for up to 96 h to a single toxicant concentration (EC 50 

# ) (Kutlu and

Susuz, 2004). The exact concentration used in the study was not reported. The EROD enzyme

is required to catalyze the c onjugation and detoxification of toxic molecules and has been

proposed as a biomarker for contaminant exposure. The authors believe more detailed studies

are required to confirm EROD as a biomarker for Pb exposure. The enzyme group alanine

transferases (ALT) has been suggested as a bi oindicator/biomarker of Pb stress (Blasco and

Puppo, 1999). A negative correlation was obs erved between Pb accumulation and ALT

concentrations in the gills and soft body of Ruditapes philippinarum exposed to 350 to 700 μg/L

of Pb for 7 days (Blasco and Puppo, 1999).

# AX7-160 Studies have identified ALAD in fish and amphi bians as a useful indicator of Pb exposure

(Gill et al., 1991; Nakagawa et al., 1995a,b). ALAD catalyzes the formation of hemoglobin and

early steps in the synthesis of protoporphyrin (Gill et al., 1991; Nakagawa et al., 1995b). The

absence of an inhibitory effect on this enzyme following exposure to cadmium, copper, zinc, and

mercury suggests that this enzyme reacts specif ically to Pb (Johansson-Sjöbeck and Larsson,

1979; Gill et al., 1991). A 0% decrease in ALAD activity was reported in common carp

( Cyprinus carpio ) exposed to a Pb concentration of 10 μg/L for 20 days (Nakagawa et al.,

1995b). The recovery of ALAD activity after exposur e to Pb has also been examined in carp

(Nakagawa et al., 1995a). After 2-week exposure to 200 μg Pb/L, ALAD activity decreased to

approximately 25% of value reported for controls (Nakagawa et al., 1995a). Fish removed from

the test concentration after 2 w eeks and placed in a Pb-free envi ronment recovered slightly, but

ALAD activity was only 50% of the controls even after 4 weeks (Nakagawa et al., 1995a).

Vogiatzis and Loumbourdis (1999) exposed the frog ( Rana ridibunda ) to a Pb concentration of

14,000 μg/L over 30 days and a 90% decrease in ALAD activity was observed in the frogs.

Blood Chemistry

Numerous studies have examined the effects of Pb exposure on blood chemistry in aquatic

biota. These studies have primarily used fish in acute and chronic exposures to Pb

concentrations ranging from 100 to 10,000 μg/L. Decreased erythroc yte, hemoglobin, and

hemocrit levels were observed in rosy barb ( Barbus puntius ) during an 8-week exposure to

126 μg/L of Pb-nitrate (Gill et al., 1991).

No difference was found in red blood cell c ounts and blood hemoglobin in yellow eels

( Anguilla anguilla ) exposed to 0 and 300 μg/L of Pb for 30 days (Santos and Hall, 1990). The

number of white blood cells, in the form of ly mphocytes, increased in the exposed eels. The

authors concluded this demonstrates the lasting action of Pb as a toxicant on the immune system

(Santos and Hall, 1990). Significant decreases in red blood cell counts and volume was reported

in blue tilapia ( Oreochromis aureus ) exposed to Pb-chloride at a concentration of 10,000 μg/L

for 1 week (Allen, 1993).

Blood components, such as plasma glucose, total plasma protei n, and total plasma

cholesterol, were unaffected in yellow eels exposed to 300 μg/L of Pb for 30 days (Santos and

Hall, 1990). Effects on plasma chemistry were observed in Oreochromis mossambicus exposed

# AX7-161 to 0, 18,000, 24,000, and 33,000 μg/L of Pb (Ruparelia et al., 1989). Significant decreases in

plasma glucose (hypoglycemic levels) were reported at concentrations of 24,000 and 33,000 Φ g

Pb/L after 14 and 21 days of exposure, and at 18,000 μg Pb/L after 21 days of exposure

(Ruparelia et al., 1989). Plasma cholesterol levels dropped significantly in comparison to

controls after 14 days of exposur e to 33,000 μg Pb/L and in all test concentrations after 21 days

of exposure (Ruparelia et al., 1989). Similarly, concentrations of blood serum protein, albumin,

and globulin were identified as bioind icators of Pb stress in carp ( Cyprinus carpio ) exposed to

Pb-nitrates at concentrations of 800 a nd 8000 μg Pb/L (Gopal et al., 1997).

Tissues

In fish, the gills serve as an active site for ion uptake. Recent studies have examined the

competition between cations for binding sites at the fish gill (e.g., Ca 2+ 

# , Mg 2+ 

# , Na + 

# , H + 

# , Pb 2+ 

# )

(MacDonald et al., 2002; Rogers and W ood, 2003, 2004). Studie s suggest that Pb 2+ 

# is an

antagonist of Ca 2+ 

# uptake (Rogers and Wood, 2003, 2004). MacDonald et al. (2002) proposed a

gill-Pb binding model that assumes Pb 2+ 

# has a ∃ 100 times greater affinity for binding sites at the

fish gill than other cations. More toxicity studies are required to quantify critical Pb burdens that

could be used as indicators of Pb toxicity (Niyogi and Wood, 2003).

Growth Responses

A negative linear relationship was observ ed in the marine gastropod abalone ( Haliotis )

between shell length and muscle Pb concentrations (Arai et al., 2002). Abalones were collected

from two sites along the Japanese coast. Haliotis discus hannai were collected from along the

coast at Onagawa; Haliotis discus were collected from along the co ast at Amatsu Kominato. The

authors did not report significant differences between the two sampling sites. From samples

collected at Onagawa, Pb concentrations of 0.03 and 0.01 μg/g were associated with abalone

shell lengths of 7.7 cm (3 years old) and 12.3 cm (6 years old), respectively. From samples

collected at Amatsu Kominato, Pb concentratio ns of 0.09 and 0.01 μg/g were associated with

abalone shell lengths of 3.9 cm (0 years old) a nd 15.3 cm (8 years old), re spectively (Arai et al.,

2002). The authors theorized that young ab alones, experiencing rapid growth, do not

discriminate between the uptake of essential a nd nonessential metals. However, as abalones

grow larger and their rate of growth decreases, they increasin gly favor the uptake of essential

# AX7-162 metals over nonessential metals. This is demonstr ated by the relatively cons istent concentrations

of Cu, Mn, and Zn that were reported fo r the abalone samples (Arai et al., 2002).

Other Physiological Effects

Increased levels of Pb in water were found to increase fish production of mucus: excess

mucus coagulates were observed over the entire body of fishes. Buildup was particularly high

around the gills, and in the worst cases, interfer ed with respiration and resulted in death by

anoxia (Aronson, 1971; National Resear ch Council of Canada., 1973).

AX7.2.3.4 Factors That Modify Organism Response to Lead

A great deal of research has b een undertaken recently to be tter understand the factors that

modify aquatic organism response to metals incl uding lead. A discussion of research on the

many factors that can modify aquatic organism re sponse to Pb is provided in this section.

Influence of Organism Age and Size on Lead Uptake and Response

It is generally accepted that Pb accumulation in living organisms is controlled, in part, by

metabolic rates (Farkas et al., 2003 ). Metabolic rates are, in-turn, controll ed by the physiological

conditions of an organism, including such factor s as size, age, point in reproductive cycle,

nutrition, and overall health. Of these physiolo gical conditions, size and age are the most

commonly investigated in relation to heavy metal uptake. This section reviews recent research

focusing on relationships between body size, age, and Pb accumulation in aquatic invertebrates

and fish.

Invertebrates

MacLean et al. (1996) investigated bioaccumula tion kinetics and toxicity of Pb in the

amphipod Hyalella azteca . Their results indicated that body size did not greatly influence Pb

accumulation in H. azteca exposed to 50 or 100 μg/L of PbCl 2 

# for 4 days. Canli and Furness

(1993) found similar results in the Norway lobster Nephrops norvegicus exposed to 100 μg/L of

Pb(NO 3 

# ) 2 

# for 30 days. No significa nt sex- or size-related differences were found in

concentrations of Pb in the tissue. The highest tissue burden was found in the carapaces (42%).

Several studies have determined that Pb can bind to the exoskeleton of invertebrates and

# AX7-163 sometimes dominate the total Pb accumulated (K nowlton et al., 1983). This adsorption of Pb to

the outer surface of invertebrates can result in strong negative relationships for whole-body Pb

concentration as a function of body mass (i.e., concentrations decr ease rapidly with increased

body size and then stabilize) (MacLean et al., 1996).

Drava et al. (2004) investigated Pb concen trations in the muscle of red shrimp Aristeus

antennatus from the northwest Mediterranean. Lead concentrations ranged from 0.04 to

0.31 μg/g dw. No significant relationships between size and Pb concentration in A. antennatus

were found, and concentrations were not related to reproductive status.

Arai et al. (2002) analyzed abalones ( Haliotis ) at various life stages from coastal regions

of Japan. They investigated growth effects on the uptake and elimination of Pb. Results

indicated a significant negative linear relati onship between age, shell length and Pb

concentrations in muscle tissue. The relationshi p was consistent despite habitat variations in

Pb concentrations between the study sites, sugge sting that Pb concentr ations changed with

growth in the muscle tissue of test specimens and implying that abalone can mitigate Pb

exposure as they age.

Fish

Douben (1989) investigated the effects of body size and age on Pb body burden in the

stone loach ( Noemacheilus barbatulus L.). Fish were caught dur ing two consecutive springs

from three Derbyshire rivers. Results indicated that Pb burden increased slightly with age.

Similarly, Köck et al. (1996) found that concentrati ons of Pb in the liver and kidneys of Arctic

char ( Salvelinus alpinus ) taken from oligotrophic alpine lakes were posi tively correlated with

age. It has been suggested that fish are not able to eliminate Pb completely, and that this leads to

a stepwise accumulation from year to year (Köck et al., 1996). In contra st, Farkas et al. (2003)

found a negative relationship between Pb concentr ations and muscle and gill Pb concentrations

in the freshwater fish Abramis brama . Fish were taken from a low-contaminated site and

contained between 0.44 and 3.24 μg/g Pb dw. Negative correlations between metal

concentration and fish size in low-contaminated wa ters likely results from variations in feeding

rates associated with developmental stages. This hypothesis is consistent with the fact that in

low-contaminated waters, feeding is the main r oute of uptake and feedi ng rates decrease with

development in fish (Farkas et al., 2003).

# AX7-164 In summary, relationships between age, size, and Pb body burden in aquatic invertebrates

and fish are interspecifically variable and depend on many envi ronment-related variables (e.g.,

exposure) (Farkas et al., 2003).

Genetics

There are few studies documenting the e ffects of Pb on organismal and population

genetics, although rapid advances in biotechnology have prompted recent research in this area

(Beaty et al., 1998). There are two principal effects that sublethal exposure to a contaminant can

have on the genetics of an organism and/or population: (1) a contaminant may influence

selection by selecting for certain phenotypes that enable populati ons to better cope with the

chemical; or (2) a contaminant can be genotoxic, meaning it can produce alterations in nucleic

acids at sublethal exposure concen trations, resulting in changes in hereditary characteristics or

DNA inactivation (Shugart, 1995). Laboratory studies have shown that exposure to Pb 2+ 

# at

10 mg/mL in blood produces chromosomal aberrations (i.e., deviations in the normal structure or

number of chromosomes) in some organisms (Ces tari et al., 2004). Eff ects of genotoxicity and

toxin-induced selection do not preclude one another, and may act together on exposed

populations. This section reviews Pb genotoxicity and the effects of Pb-induced selection in

aquatic populations.

Selection

Evidence for genetic selection in the natura l environment has been observed in some

aquatic populations exposed to metals (Rand et al., 1995; Beaty et al., 1998; Duan et al., 2000;

Kim et al., 2003). Because tolerant individua ls have a selective advantage over vulnerable

individuals in polluted environmen ts, the frequency of tolerance genes will increase in exposed

populations over time (Beaty et al ., 1998). Several studies have shown that heavy metals can

alter population gene pools in aquatic invertebrate s. These changes have resulted in decreased

genetic diversity and are thought to be a potentia l source of population instability (Duan et al.,

2000; Kim et al., 2003).

Kim et al. (2003) investigated genetic di fferences and population structuring in the

gastropod Littorina brevicula from heavy-metal polluted and unpolluted environments.

Organisms from polluted sites contained a m ean of 1.76 μg Pb/g, while organisms from

# AX7-165 unpolluted sites contained 0.33 μg Pb/g. They found significant differences in haplotypes

between the test groups and allelic di versity was significantly lower among L. brevicula from

polluted regions. In contrast, Ya p et al. (2004) performed a sim ilar experiment with the greenlipped mussel Perna viridis ; they found that mussels from contaminated sites containing between

4 and 10 μg Pb/g, as well as other heavy meta ls, exhibited a higher percentage of polymorphic

loci and excess heterozygosity compared to those from uncontaminated sites. The higher level

of genetic diversity was attribut ed to greater environmental hete rogeneity (i.e., variation due to

pollution gradients) in contaminat ed sites (Yap et al., 2004).

Duan et al. (2000) i nvestigated amphipod ( Hyalella azteca ) selective mortality and

genetic structure following acute exposure to Pb (5.47 mg/L Pb(NO 2 

# ) 2 

# ) as well as exposure to

other heavy metals. They found that genetic differentiation consiste ntly increased among

survivors from the original population, supporti ng the hypothesis that heavy metals, including

Pb, have the potential to alter th e gene pools of aquatic organisms.

Genotoxicity

Lead exposure in water (50 μg/L) over 4 weeks resulted in DNA strand breakage in the

freshwater mussel Anodonta grandis (Black et al., 1996), although hi gher concentrations (up to

5000 μg/L) did not result in significant breakag e by the end of the study period. These results

suggest that a threshold effect for DNA damage and repair exists, where DNA repair only occurs

once a certain body exposure level has been reach ed. More recently, Cestari et al. (2004)

observed similar results in neotropical fish ( Hoplias malabaricus ) that were fed Pb-contaminated

food over 18, 41, and 64 days. Lead body burdens in H. malabaricus were approximately 21 μg

Pb 2+ 

# /g. Results indicated that exposure to Pb significantly increased the frequency of

chromosomal aberrations and DNA damage in ki dney cell cultures, although when assessed at

the end of the longer exposure period s, aberrations were less common.

Environmental Biological Factors

Environmental factors that are biological in origin can alter the av ailability, uptake and

toxicity of Pb to aquatic organisms. These factors can be grouped into living and non-living

constituents. For example, living organisms ma y sequester Pb from the water column, reducing

the availability and toxicity of the metal in the water column to other biota, thus reducing

# AX7-166 potential toxic effects in othe r organisms. Non-living organi c material (e.g., components of

sloughed-off scales, mucus, carcasses, and othe r decomposing, humic material) can similarly

combine with Pb from the water column, rendering it unavailable. This section will review the

literature on biological environmen tal factors and their influence on the bioavailability, uptake,

and toxicity of Pb.

Van Hattum et al. (1996) studied the influence of abiotic va riables, including DOC on Pb

concentrations in freshwater isopods ( Proasellus meridianus and Asellus aquaticus ). They found

that BCFs were significantly negatively correlat ed with DOC concentrations. Thus, as DOC

concentrations increased, BCFs decreased in P. meridianus and A. aquaticus , indicating that

DOC acts to inhibit the availability of Pb to these isopods.

Kruatrachue et al. (2002) invest igated the combined effects of Pb and humic acid on total

chlorophyll content, growth rate, multiplicati on rate, and Pb uptake of common duckweed.

When humic acid was added to the Pb-nitrat e test solutions ( 50, 100, and 200 mg Pb(NO 3 

# ) 2 

# / L),

toxicity of Pb to duckweed was decreased. The addition of humic acid to the Pb-nitrate solution

increased the pH. The authors suggested that there was a proton dissociation from the carboxyl

group in the humic acid that complexed with Pb, resu lting in a decrease in free Pb ions available

to the plant.

Schwartz et al. (2004) collected natural organic matter ( NOM) from several aquatic sites

across Canada and investigated the effects of NOM on Pb toxicity in rainbow trout

( Oncorhynchus mykiss ). They also looked at toxicity e ffects as they related to the optical

properties of the various NOM samples. The re sults showed that NOM in test water almost

always increased LT 50 

# and that optically dark NOM tended to decrease Pb toxicity more than did

optically light NOM in rainbow trout.

In summary, non-living constituents of biologi cal origin in the environment have been

shown to reduce Pb availability a nd, therefore, toxicity in some aquatic organisms. It is

generally thought that this occurs through complexation or chelation processe s that take place in

the water column.

# AX7-167 Physicochemical Environmental Factors

This section reviews the literature on physicochemical environm ental factors and their

influence on the bioavailability, uptake, and toxic ity of Pb in aquatic organisms. These factors

are discussed with regard to their infl uence individually and in combination.

Studies generally agree that as pH increases , the toxicity of Pb decreases (Horne and

Dunson, 1995b; MacDonald et al., 2002) . As pH decreases, Pb becomes more soluble and more

readily bioavailable to aqua tic organisms (Weber, 1993). Significantly lower survival, decreased

hatching success, slower development, and in creased egg mass and la rval mortality were

observed in Jefferson salamanders ( Ambystoma jeffersonianum ) and wood frogs ( Rana sylvatica )

exposed to Pb at a pH of 4.5 versus a pH of 5.5 (Horne and Dunson, 1995b). Contradictory

results have been reported for invertebrates. Over a 96-h exposure peri od, mortality increased

with decreasing pH for the bivalve Pisidium casertanum , while pH-independent mortality was

reported for gastropods and crustacea under si milar exposure conditions (Mackie, 1989).

Cladocerans ( C. dubia ) and amphipods ( H. azteca ) were also more sensitive to Pb toxicity at pH

6 to 6.5 than at higher pH levels (Schubauer-Ber igan et al., 1993). Lead was 100 times more

toxic to the amphipod Hyalella azteca at a pH range of 5.0 to 6.0 (Mackie, 1989) than at a pH

range of 7.0 to 8.5 (Schubauer-Berigan et al., 19 93). Lead was also more toxic to fathead

minnows at lower pH levels (Sc hubauer-Berigan et al., 1993).

The influence of pH on Pb accumulation has also been observed in sediments.

Accumulation of Pb by the isopod Asellus communis was enhanced at low pH

, after a 20-day

exposure to Pb-contaminated sediment s (Lewis and McIntosh, 1986). In A. aquaticus

, temperature increases were found to be more im portant than increased pH in influencing Pb

accumulation (Van Hattum et al., 1996). Increased water temperature was also found to reduce

Pb uptake fluxes in green microalga ( Chlorella kesslerii ) (Hassler et al., 2 004). Lead and zinc

body concentrations in Asellus sp. were found to vary marked ly with seasonal temperature

changes, with greater concentrations present in spring and summer (Van Hattum et al., 1996).

Acute and chronic toxicity of Pb increases w ith decreasing water hardness, as Pb becomes

more soluble and bioavailable to aquatic orga nisms (Horne and Dunson, 1995a; Borgmann et al.,

2005). There is some evidence that water hardness and pH work together to increase or decrease

the toxicity of Pb. Jefferson salamanders expos ed to Pb for 28 days at low pH and low water

hardness experienced 50% mortality, while exposu re to Pb at high pH and high water hardness

# AX7-168 resulted in 91.7% survival (H orne and Dunson, 1995a). Exposur e to Pb at high pH and low

water hardness or low pH and high water ha rdness resulted in 75 and 41.7% survival,

respectively (Horne and Dunson, 1995a). Si milar results were reported for Jefferson

salamanders during a 7-day exposure and wood fr ogs during 7- and 28-day exposures (Horne

and Dunson, 1995c). In some cases, water hardne ss and pH in the absence of Pb have been

shown to affect survival adversely. Mean acute survival of wood frogs and Jefferson

salamanders exposed to low pH and low water hardness, in the absence of Pb, was 83.3 and

91.7%, respectively. Mean chronic survival of wood frogs and Jefferson salamanders exposed to

low pH and low water hardness, in the absence of Pb, was 79.2 and 41.7%, respectively (Horne

and Dunson, 1995c).

High Ca 2+ 

# concentrations have been shown to pr otect against the toxic effects of Pb

(Sayer et al., 1989; MacDonald et al., 2002; Hassler et al., 2004; Rogers and Wood, 2004).

Calcium affects the permeability and integrity of cell membranes and intracellular contents

(Sayer et al., 1989). As Ca 2+ 

# concentrations decrease, the passive flux of ions (e.g., Pb) and

water increases. At the lowest waterborne Ca 2+ 

# concentration (150 μmol/L), Pb accumulation in

juvenile rainbow trout ( Oncorhynchus mykiss ) branchials significantly increased as Pb

concentration in water increased (Rogers and Wood, 2004). At higher Ca 2+ 

# concentrations, Pb

accumulation did not significantly increase with Pb concentration in water. This result

demonstrates the protective effects of waterborne Ca 2+ 

# and supports the suggestion that the Ca 2+



# component of water hardness determines the toxi city of Pb to fish (Rogers and Wood, 2004).

Rogers and Wood (2004) reporte d that the uptake of Ca 2+ 

# and Pb 2+ 

# involves competitive

inhibition of apical entry at lanthanum-sensitive Ca 2+ 

# channels and interfer ence with the function

of the ATP-driven baso-lateral Ca 2+ 

# pump. High mortality was reported in brown trout ( Salmo

trutta ) fry exposed to Pb at a waterborne Ca 2+ 

# concentration of 20 μmol/L, while negligible

mortality was reported at the same Pb concentration but at a waterborne Ca 2+ 

# concentration of

200 μmol/L (Sayer et al., 1989). Adverse effect s to mineral uptake a nd skeletal development

were observed in the latter test group (Sayer et al., 1989).

The bioavailability of Pb and other metals that can be simultaneously extracted in

sediments may be modified through the role of acid volatile sulf ide (AVS) under anoxic

conditions (Tessier and Campbell, 1987; Di Toro et al., 1992; Casas and Crecelius, 1994). The

term AVS (iron sulfide is an example) refers to the fraction of the sediment that consists of a

# AX7-169 reactive pool of solid-phase sulfide. This phase is available to bind divalent metals that then

become unavailable for uptake by aquatic biota. The models proposed by Di Toro et al. (1992)

and Casas and Crecelius (1994) predict that when the molar ratio of simultaneously extractable

metals (SEM) to AVS in sediments is less than one, the metals will not be bioavailable due to

complexation with available sulfide.

Salinity is an important modi fying factor to metal toxici ty. Verslycke et al. (2003)

exposed the estuarine mysid Neomysis integer to individual metals , including Pb, and metal

mixtures under changing salinity. At a salinity of 5%, the reported LC 50 

# for Pb was 1140 μg/L

(95% CL = 840, 1440 μg/L). At an increased salinity of 25 l , the toxicity of Pb was substantially

reduced (LC 50 

# = 4274 μg/L [95% CL = 3540, 5710 μg/L]) (Verslycke et al., 2003). The

reduction in toxicity was attributed to increased complexation of Pb 2+ 

# with Cl ! 

# ions.

Nutritional Factors

The relationship between nutrition and Pb toxic ity has not been thoroughly investigated in

aquatic organisms. In fact, algae species are the only aquatic organisms to have been studied

fairly frequently. Although nutrients have been found to have an impact on Pb toxicity, the

mechanisms involved are poorly understood. It is unclear whether the relationship between

nutrients and toxicity comprises organismal nut rition (the process by wh ich a living organism

assimilates food and uses it for growth and for replacement of tissues), or whether nutrients have

interacted directly with Pb, inhibiting its metabol ic interaction in the organism. This section

reviews the little information that has been gathered from studies documenting apparent Pbnutrition associations in aquatic organisms.

Jampani (1988) looked at the impact of various nutrients (i.e., sodium acetate, citric acid,

sodium carbonate, nitrogen, and phosphates) on reduc ing growth inhibition in blue-green algae

( Synechococcus aeruginosus ) exposed to 200 mg Pb/L. E xposure to this Pb treatment

concentration caused 100% mortality in algae. Results indicated that additional nitrogen,

phosphates, and some carbon sources, including sodium acetate, citric acid and sodium

carbonate, all protected the algae fr om Pb toxicity. Algae that had been starved prior to the

experiment were found to be significantly more sensitive to Pb exposure. Glucose was the only

nutrient tested that did not have a si gnificant impact on Pb toxicity in S. aeruginosus . In a

similar study by Rao and Reddy (1985) on Scenedesmus incrassatulus , nitrogen, phosphate and

# AX7-170 carbon sources (including glucose), all had protectiv e effects, and reduced Pb toxicity at 300 and

400 mg Pb/L. Both studies proposed similar hypot heses regarding nutrient-Pb mechanisms that

led to reduced toxicity. One hypothe sis was that the nutrients were ab le to reverse toxic effects.

The second hypothesis was that the nutrients in teracted directly with Pb, in some way

sequestering the metal so as to inhibit its metabolic interaction with the organism (Rao and

Reddy, 1985; Jampani, 1988).

Rai and Raizada (1989) investig ated the effects of Pb on nitrate and ammonium uptake as

well as carbon dioxide and nitrogen fixation in Nostoc muscorum over a 96-h period. Test

specimens were exposed to 10, 20, and 30 mg Pb/L. At 20 mg Pb/L, nitrate uptake was inhibited

by 64% after 24 h and by 39% after 96 h. Am monium uptake was inhibited, and similarly,

inhibition decreased from 72% i nhibition after 24 h to 26% inhibi tion after 96 h of exposure.

Carbon dioxide fixation and nitroge nase activity followed similar pa tterns, and results indicated

that Pb exposure can affect th e uptake of some nutrients in N. muscorum

.
Adam and Abdel-Basset (1990) studied the e ffect of Pb on meta bolic processes of

Scenedesmus obliquus . They found that nitrog enase activity was inhibi ted by Pb nitrate, but

enhanced by Pb-acetate. As photosynthetic pr oducts and respiratory substrates, carbohydrate

and lipid levels were altered by Pb. Above 30 mg/L of Pb-nitrate, both macronutrients were

reduced. However, Pb-acetate was found to incr ease carbohydrate levels. Results suggest that

Pb can have an effect on macronutrients in S. obliquus and that effects may vary depending on

the chemical species.

Simòes Gonçalves et al. (1991) studied the impact of light, nutrients, air flux, and Pb, in

various combinations, on growth inhibition in the green algae Selenastrum capricornutum

.

Results indicated that at lo wer Pb concentrations (<0.207 mg/L) and increased nutrient

concentrations, algae release more exudates that form inert comp lexes with Pb anions in the

water. This suggests that S. capricornutum can use exudates as a protection and that this

protective mechanism depends on nutrient supply. These results are consis tent with those of

Capelo et al. (1993), who investigated uptak e of nitrogen and phosphorus in the algae

Selenastrum capricornutum over time in the absence and pr esence of 0.207 mg Pb/L. They

found that the presence of Pb ha d no significant influence on the assimilation of nitrogen and

phosphorus. However, they did find that in the presence of Pb, algae released higher

concentrations of organics with Pb-chelating groups.

# AX7-171 Amiard et al. (1994) investigated the impact on soft tissue Pb concentrations of various

feeding regimes on oysters ( Crassostrea gigas ) during their spat rearing. They fed test groups of

C. gigas different amounts of Skeletonema costatum and additional natural phytoplankton grown

in test solutions. Results showed that size and food intake both negatively correlated with metal

concentrations in soft tissue. The authors hypothesi zed that this relationshi p was due in part to a

diluting effect of the food.

In summary, nutrients affect Pb toxicity in t hose aquatic organisms that have been studied.

Some nutrients seem to be capable of reducing toxicity, though the mechanisms have not been

well established. Exposure to Pb has not been shown to reduce nutrien t uptake ability, though it

has been demonstrated that Pb exposure may l ead to increased production and loss of organic

material (e.g., mucus and other complex organic ligands) (Cap elo et al., 1993).

Interactions with Other Pollutants

Most of the scientific literature reviewed in this section considered how Pb and other

elements combine to affect uptak e and exert toxicity. Research on the interactions of Pb with

complexing ligands and other physic al and biological factors was more t horoughly discussed in

Section AX7.2.3.4. Predicting the response of organi sms to mixtures of chemicals is difficult

(Norwood et al., 2003). There are two schools of thought on addressing chemical mixtures in

toxicology. The first focuses on the combined mode of action of the individual mixture

substances while the other focuses on the organism response to the mixture as being additive, or

some deviation from additive (synergistic or an tagonistic). The mode of action model assumes

that each of the individual substances has sim ilar pharmacokinetics as well as mode of action.

Approaches to modeling combined mode of ac tion include: 1) joint independent action for

toxicants with different modes of action; and 2) joint similar mode of action. Within the

scientific literature the deviations from additivity approach can be confusing as some authors

report concentration additivity, while others report effect additivit y. The concentration additivity

model assumes that the sum of the concentrations will result in a level of effect similar to the

simple sum of the effects observed if each chemi cal were applied separately (e.g., Herkovits and

Perez-Coll, 1991). Toxic units (TU) may be used to describe the concentration additivity results

for mixtures (e.g., Hagopian-Schlekat et al., 2001). Effects additivity sugges ts that the level of

effect of a mixture will be the sum of the effects of each chemical used separately. Thus, the

# AX7-172 separate concentration-effects models for each chem ical are used to predict individual effects and

the sum of these predictions is then compared to the actual effect of the mixture. Deviations

from the mixture effect are then classified as less than addi tive (antagonistic) or more than

additive (synergistic) (see Piegorsch et al ., 1988; Finney 1947 for further information).

The complexity of metal mixture interact ions as different metal concentrations,

environmental conditions (e.g., temperature, pH), and other factors can cause marked changes in

the effects observed (Norwood et al., 2003). In describing Pb interactions with other elements,

the different approaches to modeling mixture toxi city are considered. Specific reference to

known Pb-metal interactions and implications on Pb uptake and toxicity will also be made in

each of the studies below.

Less than additive or antagonistic interactions can reduce metal bioavailability when

metals are present in combination, and may lead to reduced potential for toxicity (Hassler et al.,

2004). A number of elements act in an antagonistic fashion with P b. For example, Pb is a wellknown antagonist to Ca 2+ 

# (Niyogi and Wood, 2004; Hassler et al., 2004), which is an essential

element, required for a number of physiological pr ocesses in most organisms. Lead ions have an

atomic structure similar to Ca 2+ 

# and can be transported either actively or passively across cell

membranes in place of Ca 2+ 

# . An example of this interaction was reported by Behra (1993a,b)

where Pb was shown to activate calm odulin reactions in rainbow trout ( O. mykiss ) and sea

mussel ( Mytilus sp.) tissues in the absence of cal cium. Calmodulin (CaM) is a major

intracellular calcium receptor and regulates th e activities of numerous enzymes and cellular

processes. Allen (1994) reported that Pb can replace calcium in body structures (e.g., bones,

shells); replace zinc in ALAD, which is requ ired for heme biosynthesis; and react with

sulfhydryl groups, causing conformation protein distortion and scission of nucleic acids

(Herkovits and Perez-Coll, 1991). Lead is also a known antagonist to Mg 2+ 

# , Na + 

# , and Cl !



# regulation in fish (Ahern and Morris, 1998; Rogers and Wood, 2003, 2004; Niyogi and Wood,

2004). Li et al. (2004) repor ted on the interaction of Pb 2+ 

# with Cd 2+ 

# in the context of adsorption

from solution by Phanerochaete chrysosporium , a filamentous fungus. The authors found that

cadmium uptake decreased with increasi ng concentration of Pb ions with Pb 2+ 

# outcompeting

Cd 2+ 

# for binding sites.

Hassler et al. (2004) reported that in the presence of copper (Cu 2+ 

# ), there was a

significantly higher rate of interna lization of Pb in the green algae Chlorella kesserii . It was

# AX7-173 suggested that Cu 2+ 

# may have affected organism phys iology through the disruption of cell

membrane integrity. This would allow increased cation (i.e., Pb 2+ 

# ) permeability and, therefore,

substantially increase internalization of Pb and result in effects that were more than additive

(synergistic). Hagopian-Schlekat et al. (2001) ex amined the impact of individual metals and

complex metal mixtures containing Cd, Cu, Ni, Zn, and Pb to the estuarine copepod Amphiascus

tenuiremis . The copepods were exposed to metal-spik ed sediment and pore water. The mixed

metal sediment toxicity tests demonstrat ed greater than additive toxicity to A. tenuiremis . It was

postulated that the synergism observed was due to two or more metals affecting the same

biological function. Herkovits and Perez-Coll (1991) exposed Bufo arenarum larvae to various

Pb and zinc concentrations in solution. At low zinc concen trations, (2:1 Pb:Zn ratio),

a synergistic toxic effect was obs erved in the frog larvae relativ e to the effects observed from

exposure to the individual metals and at higher zi nc concentrations. Enhanced Pb toxicity was

attributed to the interference of Pb with cellular activities due to binding with sulfhydryl

polypeptides and nucleic acid phos phates (Herkovits and Pere z-Coll, 1991). Allen (1994)

reported on the accumulation of numerous metals a nd ions into specific tissues of the tilapia

Oreochromis aureus . Tilapia exposed to low concentra tions of Pb and mercury (both at

0.05 mg/L) had significantly higher concentrations of Pb in internal organs than those fish

exposed to Pb alone. Similarly, low concentrati ons of cadmium with low concentrations of Pb

caused increased uptake of Pb in certain or gans (e.g., liver, brain, and caudal muscle).

Lead has been shown to complex with Cl ! 

# in aquatic systems. For example, Verslycke

et al. (2003) exposed the estuarine mysid Neomysis integer to six different me tals, including Pb,

and a combined metal mixture under changing sali nity conditions. At a salinity of 5%, the

reported LC 50 

# for Pb was 1140 μg/L (840, 1440 μg/L). At an increased salinity of 25 l , the

toxicity of Pb was s ubstantially reduced (LC 50 

# = 4274 μg/L [3540, 5710 Φ g/L]) (Verslycke

et al., 2003). This reduction in toxicity was a ttributed to the increas ed concentration of Cl ! 

# ion

due to increased salinity, in that it complexed with divalent Pb in the te st system. Exposure of N.

integer to Pb in combination with the other five metals (Hg, Cd, Cu, Zn, Ni) resulted in roughly

strictly additive toxicity (Verslycke et al., 2003).

Long et al. (2006) performed a critical review of the uses of mean sediment quality

guideline quotients (mSQGQs) in assessing the toxi c effects of contaminant mixtures (metals and

organics) in sediments. This approach has b een used in numerous su rveys and studies since

# AX7-174 1994. mSQGQs are useful to risk assessors but their inherent limitations and underlying

assumptions must be fully unde rstood (see Section AX7.2.1.5).

Summary of Interactions With Other Pollutants

Norwood et al. (2003) reported th at in a review and reinterp retation of published data on

the interactions of metals in binary mixtures (n = 15 studies), antagonistic (6) and additive

interactions (6) were the most common for Pb. The complexity of the interactions and possible

modifying factors makes determining the impact of even binary metal mixtures to aquatic biota

difficult (Norwood et al., 2003; Playle, 2004). The two most commonly reported Pb-element

interactions are between Pb and calcium and between Pb and zinc . Both calcium and zinc are

essential elements in organisms and the interactio n of Pb with these ions can lead to adverse

effects both by increased Pb uptake and by a decrease in Ca and Zn required for normal

metabolic functions.

AX7.2.3.5 Factors Associated with Global Climate Change

It is highly unlikely that Pb has any in fluence on generation of ground-level ozone,

depletion of stratospheric ozone, global warming, or other indicator s of global climate change.

Lead compounds have relatively short residence times in the atmosphere, making it unlikely that

they will reach the stratosphere, and they do not absorb infrared radiation, making them unlikely

to contribute to stratospheric ozone depletion or global warming. Also, these compounds are

unlikely to have a significant interaction with gro und-level nitrogen oxides or volatile organic

compounds, thus precluding genera tion of ground-level ozone.

Approached from another viewpoint, climat e change can have a major impact on the

fate/behavior of Pb in the environment and, th erefore, can subsequently alter organism or

ecosystem responses. For example, changes in temperature regime (Q10 rule), changes in

precipitation quantity and quality (e.g., acidic deposition) may influence fate, transport, uptake,

and bioavailability of Pb (Syracuse Research Corporation., 1999).

AX7.2.3.6 Summary

There have been a number of advancements in the understanding of Pb behavior in the

environment and its impact on aquatic organisms since 1986. In particular , greater knowledge of

# AX7-175 factors that influence Pb accumulation in aquati c organisms, mechanisms of detoxification and

avoidance of Pb, and greater underst anding of the interactions of Pb in aquatic systems. All of

these factors require some consideration when a ttempting to determine the potential for exposure

and subsequent response of aquatic species to lead. The following section provides a review on

the current understanding of lead and its impacts on aquatic biota.



# AX7.2.4 Exposure/Response of Aquatic Species

This section outlines and highlights the critic al recent advancements in the understanding

of the toxicity of Pb to aquatic biota. The sect ion begins with a review of the major findings and

conclusions from the 1986 Lead AQCD (U.S. En vironmental Protection Agency, 1986a). The

following sections summarize the research conducted since 1986 on determining the

concentrations of Pb that cause th e effects discussed in Section 7.2.3.

Lead exposure may adversely affect organisms at different levels of organization, i.e.,

individual organisms, populations, communities, or ecosystems. Generally, however, there is

insufficient information available for single mate rials in controlled studies to permit evaluation

of specific impacts on higher levels of organizatio n (beyond the individual organism). Potential

effects at the population level or higher are, of necessity, extrapolated from individual level

studies. Available population, community, or ecos ystem level studies are typically conducted at

sites that have been contaminated or adversely affected by multiple stressors (several chemicals

alone or combined with physical or biological stressors). Theref ore, the best documented links

between lead and effects on the environment are w ith effects on individual organisms. Impacts

on aquatic ecosystems are discussed in Section 7.2.5 and Annex AX7.2.5.

AX7.2.4.1 Summary of Conclusions From the Previous Criteria Document

The 1986 Lead AQCD (U.S. Environmental Prot ection Agency, 1986a) reviewed data in

the context of the sublethal eff ects of lead exposure. The do cument focused on describing the

types and ranges of lead exposures in ecosystems likely to adversely impact domestic animals.

As such, the criteria document did not provide a co mprehensive analysis of the effects of lead to

most aquatic primary producers, consumers, and decomposers. For the aquatic environment,

general reviews of the effects of lead to alga e, aquatic vertebrates, and invertebrates were

undertaken. A summary of these reviews is provided below.

# AX7-176 Algae

The 1986 Lead AQCD (U.S. Environmental Protection Agency, 1986a) reported that

some algal species (e.g., Scenedesmus sp.) were found to exhibit physiological changes when

exposed to high lead or organolead concentratio ns in situ. The observed changes included

increased numbers of vacuoles, deformations in cell organelles, and increased autolytic activity.

Increased vacuolization was assumed to be a tolerance mechanism by which lead was

immobilized within cell vacuoles.

Aquatic Vertebrates

The 1986 Lead AQCD (U.S. Environmental Protection Agency, 1986a) reported that

hematological and neurological responses were the most commonly reported effects in aquatic

vertebrates. These effects include red blood cell destruction and inhi bition of the enzyme

ALAD, required for hemoglobin synthesis. At hi gh lead concentrations, neurological responses

included neuromuscular distortion, anorexia, muscle tremor, and spinal curvature (e.g., lordosis).

The lowest reported exposure concentration causing either hematological or neurological effects

was 8 μg/L (U.S. Environmental Protection Agency, 1986a).

Aquatic Invertebrates

Numerous studies were cited on the effects of lead to aqua tic invertebrates in the 1986

Lead AQCD (U.S. Environmental Protection Agency, 1986a). In general, lead concentrations in

aquatic invertebrates were found to be correlated cl osely with concentrations in water rather than

food. Freshwater snails were found to accumulate l ead in soft tissue, ofte n in granular bodies of

precipitated lead. Mortality and reproductive effects were reported to begin at 19 μg Pb/L for the

freshwater snail Lymnea palutris and 27 μg Pb/L for Daphnia sp.

The review of the NAAQS for Pb (U.S. E nvironmental Protection Agency, 1990) made

only one recommendation reported in the sections of the 1986 Lead AQCD dealing with effects

to aquatic biota. This was the need to consider the impact of water hardness on Pb

bioavailability and toxicity, to be consistent with the recommendations of the AWQC for the

protection of aquatic life (U.S. Envi ronmental Protection Agency, 1985).

# AX7-177 AX7.2.4.2 Recent Studies on Effects of Lead on Primary Producers

Using literature published si nce the 1986 Lead AQCD (U.S . Environmental Protection

Agency, 1986a), this section examines the toxicity of Pb (individually and in metal mixtures) to

algal and aquatic plant growth, its effects on metabolic processe s (e.g., nutrient uptake), and its

impact on primary productivity in natural systems.

Toxicity of Lead to Algae

The toxicity of Pb to algal growth has been investigated for a number of species including

Chlorella vulgaris

, Closterium acerosum

, Pediastrum simplex

, Scenedesmus quadricauda

,
Scenedesmu obliquus

, Syneschoccus aeruginosus , and Nostoc muscorum (Jampani, 1988; Rai

and Raizada, 1989; Adam and Abdel-Basset, 19 90; Fargašová, 1993; Bilgrami and Kumar,

1997). Study durations ranged from 7 to 20 days and Pb-nitrate was the most commonly used

form of Pb. Effect s to algal growth ( Chlorella vulgaris

, Closterium acerosum

, Pediastrum

simplex

, Scenedesmus quadricauda ), ranging from minimal to complete inhibition, have been

reported at Pb concentrations between 100 and 200,000 μg/L (Jampani, 1988; Bilgrami and

Kumar, 1997). Most studies report the percent inhibition in test groups compared to controls

rather than calculati ng the LOEC, NOEC, or EC 50 

# values. Clinical signs of Pb toxicity include

the deformation and disintegration of algae cel ls and a shortened exponential growth phase

(Jampani, 1988; Fargašová, 1993). Other effects of Pb block the pathways that lead to pigment

synthesis, thus affecting photosynthesis, the cel l cycle and division, and ultimately result in cell

death (Jampani, 1988).

From the studies reviewed, Closterium acerosum is the most sensitive alga species tested

(Bilgrami and Kumar, 1997). Exposure of these algae to 1000 and 10,000 μg/L as lead nitrate

for 6 days resulted in cell gr owth that was 52.6 and 17.4%, respec tively, of controls (Bilgrami

and Kumar, 1997). Chlorella vulgaris

, Pediastrum simplex , and Scenedesmus quadricauda were

also exposed to Pb-nitrate in this study. Compared to controls, cell growth at 1000 and

10,000 μg Pb-nitrate/L was 65.3 and 48.7%, 64.5 and 42.7%, and 77.6 and 63.2%, respectively

(Bilgrami and Kumar, 1997). Scenedesmus quadricauda exhibited a similar magnitude of effects

when exposed to lead (Pb 2+ 

# ) for 20 days at 0, 5500, 11,000, 16,500, 22,000, 27,500, and

33,000 μg/L (Fargašová, 1993). This study reported an EC 50 

# for growth inhibition at

13,180 μg/L (95% CI: 10,190, 14,620). Decreased cell number, but incr eased cell size, was

# AX7-178 observed in Selenastrum capricornutum 7 

# exposed to lead (Pb 2+ 

# ) at 207.2 μg/L and a Q/V (flux of

air [Q] divided by volume of the culture [V]) of 4.7 Η 10 ! 3 

# sec ! 1 

# for 9 days (Simòes Gonçalves

et al., 1991). The Q/V is a measure of culture growth where an increase in the Q/V ratio

indicates growth. The pigment concentration per cell decreased with exposure to Pb, so while

the algae cells were larger, they were less hea lthy (Simòes Gonçalves et al., 1991). Growth rates

were not reported, making comparison with other studies difficult.

High Pb concentrations were required to elicit effects in Nostoc muscorum and

Scenedesmus aeruginosus (Jampani, 1988; Rai and Raizada, 1989). Following 15-day

exposures, test groups exposed to 10,000, 20,000, a nd 30,000 μg Pb/L experienced growth rates

that were 90.5, 76.9, and 66.7% of the controls (Rai and Raizada, 1989). Synechococcus

aeruginosus experienced little inhibiti on of growth from exposure to Pb-nitrate up to a

concentration of 82,000 μg/L (Jampani, 1988). At a test concentration of 100,000 μg/L,

complete inhibition of growth was observed, and at a concentration of 200,000 μg/L, algae failed

to establish a single colony (Jampani, 1988). Scenedesmus obliquus are quite tolerant to the

effects of Pb-nitrate and Pb-acetat e on growth. Algae exposed to Pb-nitrate or Pb-acetate up to

180,000 μg/L had higher cell numbers than controls (Adam and Abdel-Basset, 1990). Exposure

to the highest concentration of 300,000 μg/L Pb-n itrate or Pb-acetate resulted in cell numbers

that were 81 and 90% of the controls, re spectively (Adam and Abdel-Basset, 1990).

Lead in combination with other metals (e.g., Pb and Cd, Pb and Ni, etc.) is generally less

toxic than exposure to Pb al one (Rai and Raizada, 1989). Nostoc muscorum exposed to

chromium and Pb in combination demonstrated bette r growth than when exposed to either of the

metals alone (Rai and Raizada, 1989). Antagonis tic interaction was obser ved in the exposure of

Nostoc muscorum to Pb and nickel in combination (R ai and Raizada, 1989). When applied

separately, these metals demonstr ated different levels of toxic ity; however, in combination, they

exerted similar effects (Rai and Raizada, 1989). More information on toxic interactions of Pb

with other metals is provided in Section AX7.2.3.5.

7 

# The species name Selenastrum capricornutum has been changed to Pseudokirchneriella subcapitata . The
former species name is used in this report.

# AX7-179 Aquatic Plants

The toxicity of Pb to aquatic pl ant growth has been studied using Spirodela polyrhiza

,
Azolla pinnata , and Lemna gibba (Gaur et al., 1994; Gupta a nd Chandra, 1994; Miranda and

Ilangovan, 1996). Test durations ranged from 4 to 25 days and test c oncentrations ranged

between 49.7 and 500,000 μg Pb/L (Gaur et al., 1994; Miranda and Ilangovan, 1996). Research

on aquatic plants has focused on the effects of Pb on aquatic plant grow th and chlorophyll and

protein content.

Of the species reviewed here , the effects of Pb on aqua tic plant growth are most

pronounced in Azolla pinnata (Gaur et al., 1994). An EC 50 

# of 1100 μg/L was reported for

A. pinnata exposed to Pb-nitrate for 4 days. S. polyrhiza exposed to Pb-nitrate under the same

test conditions had a reported EC 50 

# for growth of 3730 μg/L (Gaur et al., 1994). Lemna gibba

was shown to be the least sens itive plant species to Pb: si gnificant growth inhibition was

reported at concentrations of 200,000 μg/L or greate r after 25 days of expos ure to concentrations

of 30,000, 50,000, 100,000, 200,000, 300,000, or 500,000 μg/L (M iranda and Ilangovan, 1996).

The maximum growth rate for L. gibba was observed at 10 days of exposure. After this point,

the growth rate declined in controls and te st concentrations (Mir anda and Ilangovan, 1996).

Clinical signs of Pb toxicity include yellowi ng and disintegration of fronds, reduced frond size,

and chlorosis (Gaur et al., 1994; Miranda and Il angovan, 1996). Toxicity results suggest that

effects to growth from Pb exposure occur in a dose-dependent manner (Gaur et al., 1994).

Effects of Lead on Metabolic Processes

Algal and aquatic plant metabolic processes ar e variously affected by exposure to Pb, both

singularly and in combination with other metals. Lead adversely affects the metabolic processes

of nitrate uptake, nitrogen fixa tion, ammonium uptake, and carbon fixation at concentrations of

20,000 μg Pb/L or greater (Rai and Raizada, 1989). Lead in co mbination with nickel has an

antagonistic effect on nitrogen fi xation and ammonium uptake, but a synergistic effect on nitrate

uptake and carbon fixation (Rai and Raizada, 1989). Lead in comb ination with chromium has an

antagonistic effect on nitrate up take, but it has a synergistic effect on nitrogen fixation,

ammonium uptake, and carbon fixati on (Rai and Raizada, 1989).

Lead effects on nitrate uptake in Nostoc muscorum (μg NO 3 

# /μg Chl a ) were greatest after

24 h, when exposure to 20,000 μg/L reduced nitr ate uptake by 64.3% compared to controls.

# AX7-180 Nitrate uptake reported after 48, 72, a nd 96 h was reduced by 30.0, 37.5, and 38.9%,

respectively, compared to controls (Rai a nd Raizada, 1989). Lead in combination with

chromium, both at a test c oncentration of 20,000 μg/L, demons trated antagonistic effects on

nitrate uptake. Compared to controls, nitr ate uptake was reduced by 52.4, 30, 25, and 22.2% at

24, 48, 72 and 96 h, respectively (Rai and Rai zada, 1989). The greatest effect on uptake

occurred at 24 h when, compared to controls , a 52.4% reduction was re ported in the test

concentration. Lead and nickel in combinati on at test concentrations of 20,000 and 1000 μg/L,

respectively, resulted in a grea ter reduction of nitrate uptake than Pb alone at 48, 72, and 96 h

(Rai and Raizada, 1989).

After 24, 48, and 72 h of Pb exposure at 20,000 μg/L, nitrogenase activity (nmol C 2 

# H 4 

# / μg

protein/hr) in Nostoc muscorum was reduced by 39.3, 61.8, and 14.1%, respectively, compared

to controls (Rai and Raizada, 1989). A concen tration of 207.2 μg Pb/L had little effect on

nitrogen or phosphorus assimilation in Selenastrum capricornutum over 7 days (Capelo et al.,

1993). An antagonistic effect on nitrogenase activity was generally reported for Nostoc

muscorum exposed to Pb in combination with nickel at 20,000 and 1,000 μg/L, respectively

(Rai and Raizada, 1989). Compared to cont rols, nitrogenase activ ity was reduced by 42.9, 32.7,

and 13.6% at 24, 48, and 72 h, respectively (Rai a nd Raizada, 1989). Lead and chromium, both

administered at a concentration of 20,000 μg/L, ha d a synergistic impact on nitrogenase activity

in Nostoc muscorum . Nitrogenase activity in the te st group was reduced by 60.7, 60, and 50%

compared to the controls at 24, 48, and 72 h, respectively (Rai and Raizada, 1989).

Lead-induced inhibition of ammonium uptake (μg NH 4 

# uptake/μg Chl a ) was greatest in

Nostoc muscorum after 48 h of exposure to 20,000 μg/L of lead. Compared to controls, the Pb

test concentration 20,000 μg/L reduced a mmonium uptake by 72, 82, 61, and 26 % at 24, 48, 72,

and 96 h, respectively (Rai and Raizada, 1989). Lead in combination with nickel at

concentrations of 20,000 and 1,000 μg/L, respective ly, demonstrated an antagonistic effect on

ammonium uptake. Compared to controls, ammonium uptake in the test group was reduced by

44.9, 54.1, 23.3, and 4% at 24, 48, 72, and 96 h, respectiv ely (Rai and Raizada, 1989). Lead in

combination with chromium, both at concentrat ions of 20,000 μg/L, demonstrated a synergistic

interaction with 24, 48, 72, and 96 h uptake rates reduced by 87.2, 88.5, 72.5, and 50 %,

respectively, compared to controls (Rai and Raizada, 1989).

# AX7-181 Nostoc muscorum exposed to 20,000 μg Pb/L experien ced the greatest reduction in carbon

fixation at 0.5 h of exposure: 62% compared to controls. Inhibiti on of carbon fixation in the test

group was less pronounced after 1 and 2 h of expos ure: 29 and 13% of controls (Rai and

Raizada, 1989). Lead in combination with nick el or chromium had synergistic effects to carbon

fixation. Lead and nickel concentrations of 20,000 and 1000 μg/L, respectively, resulted in 0.5,

1, and 2 h carbon fixation rates reduced by 93, 92, and 91%, respectively, compared to controls

(Rai and Raizada, 1989). Lead with chromium at concentrations of 20,000 μg/L resulted in 0.5,

1, and 2 h carbon fixation rates reduced by 65, 58, a nd 50%, respectively, compared to controls.

Nutrients such as nitrogen, phosphate, sodium acetate, sodium carbonate, and citric acid

have been shown to protect against the toxic effects of Pb to algae (Jampani, 1988). Nitrogen

compounds (ammonium chloride, potassium nitrate, sodium nitrate, sodium nitrite) protected

Synechococcus aeruginosus from a lethal Pb-nitrate dose of 200,000 μg/L (Jampani, 1988). Two

phosphates (K 2 

# HPO 4 

# and Na 2 

# HPO 4 

# ) were found to improve Synechococcus aeruginosus survival

from 0 to 72% at 200,000 μg/L of Pb-nitrate (Jampani, 1988).

Compared to controls, protein content wa s reduced by 54.2 and 51.9% in aquatic plants

Vallisneria spiralis and Hydrilla verticillata , respectively, exposed to Pb for 7 days at

20,720 μg/L (Gupta and Chandra, 1994). Decreased soluble protein content has been observed

in Scenedesmus obliquus exposed to Pb-nitrate or Pb-acetate at concentrations greater than

30,000 μg/L, and in L. gibba at concentrations greater than 200,000 μg/L (Adam and

Abdel-Basset, 1990; Miranda and Ilangovan, 1996). Lemna gibba also showed increased loss of

soluble starch at concentrations >200,000 μg /L (Miranda and Ilangovan, 1996). Under the

conditions described previously (Gupta and Chandra, 1994), EC 50 

# values for chlorophyll content

were 14,504 and 18,648 μg/L for Vallisneria spiralis and Hydrilla verticillata , respectively

(Gupta and Chandra, 1994). Effects to chlorophyll a content have been observed in

Scenedesmus obliquus at Pb-nitrate and Pb-acetate con centrations >30,000 μg/L (Adam and

Abdel-Basset, 1990).

Summary of Toxic Effects Observed in Single-Species Bioassays

Algae and aquatic plants have a wide range in sensitivity to the effects of Pb in water.

Both groups of primar y producers experience EC 50 

# values for growth inhibition between

approximately 1000 and >100,000 μg/L (Jampani, 1988; Gaur et al., 1994; Bilgrami and Kumar,

# AX7-182 1997). The most sensitive primary producers reported in the literature for e ffects to growth were

Closterium acersoum and Azolla pinnata (Gaur et al., 1994; Bilgrami and Kumar, 1997). The

least sensitive primary producers reported in the literature for effects to growth were

Synechococcus aeruginosus and Lemna gibba (Jampani, 1988; Miranda and Ilangovan, 1996).

Exposure to Pb in combination with other metals is generally less toxic to growth than exposure

to lead alone. Studies have shown that lead a dversely affects the metabolic processes of nitrate

uptake, nitrogen fixation, ammonium uptake, a nd carbon fixation (Rai and Raizada, 1989). Lead

in combination with nickel or chromium produced synergisti c effects for nitrate uptake,

nitrogenase activities, ammonium uptake, and carbon fixati on (Rai and Raizada, 1989).

Leads Effects on Primary Productivity

Lead nitrate and Pb-acetate have been s hown to have adverse effects on the primary

productivity of aquatic plants in two water bodies in India (Jayar aj et al., 1992). One of the two

water bodies was a freshwater tank that receive s wastewater and supports a rich population of

hyacinths, and the other was a wast ewater stabilization pond. Water quality characteristics in the

freshwater tank were pH = 7.5, dissolved oxygen = 6 mg/L, and water hardness (CaCO 3 

# ) =

100 mg/L. Water quality characteristics in the wastewater pond were pH = 8.1, dissolved

oxygen = 6.2 mg/L, and water hardness (CaCO 3 

# ) = 160 mg/L (Jayaraj et al., 1992). Lead nitrate

concentrations of 500, 5000, 10,000, 25,000, and 50,000 μg/L were combined with appropriate

water samples in light and dark bottles and susp ended in each of the water bodies for 4 h. The

concentrations of Pb-acetate (5000, 1 0,000, 25,000, 50,000, and 100,000 μg/L) were applied in

the same manner. The EC 50 

# values were determined based on the concentra tion required to

inhibit gross productivity (GP) and net productivity (NP) by 50% (Jayaraj et al., 1992). The

results demonstrated that Pb-nitrate was more toxic to primary production than Pb-acetate.

In the freshwater tank, Pb-nitrate EC 50 

# values for GP and NP were 25,100 and 6310 μg/L,

respectively, compared to Pb-acetate EC 50 

# values of 50,100 and 28,200 μg/L for GP and NP,

respectively (Jayaraj et al., 1992). In the stabilization pond, Pb-nitrate EC 50 

# values for GP and

NP were 31,600 and 28,200 μg/L, respectively, compared to Pb-acetate EC 50 

# values of 79,400

and 316 μg/L for GP and NP, respectively (Jayaraj et al., 1992). The higher toxicity reported in

the freshwater tank was attributed to differences in species composition and diversity. The

freshwater tank was dominated by water hyacinths that decreased the photic zone available for

# AX7-183 photosynthesis and consumed a great deal of av ailable nutrients. The stabilization pond had

a rich nutrient budget, resulti ng in improved alga growth a nd species diversity (Jayaraj

et al., 1992).

AX7.2.4.3 Recent Studies on Effe cts of Lead on Consumers

This section focuses on the effects of Pb to a quatic biota including i nvertebrates, fish, and

other biota with an aquatic life stage (e.g., amphibians). It is not intended to be a comprehensive

review of all research conducted. Rather, the intent is to illustrate the conc entrations and effects

of Pb on freshwater and marine aquatic species. Eisler (2000) provides an overview of much of

the recent available literature on the toxicity of Pb to fish and aquatic invertebrates. An

extensive literature search was conducted using numerous electronic bibl iographic and database

services (e.g., DIALOG, EPA ECOTOX) and limited temporally from 1986 to present. This

temporal limit was due to the availability of the EPA water quality criteria report for the

protection of aquatic life, released in 1986 (U.S. Environmental Protection Agency, 1986b).

Based on the results of the litera ture search and recent reviews of the toxicity of Pb (Eisler,

2000), numerous studies have been published on th e toxicity of Pb to aquatic consumers.

Hardness, pH, temperature, and other factors ar e important considerations when characterizing

the acute and chronic to xicity of lead (Besser et al., 2005) (Section AX7.2.3.5). However, many

of the studies reviewed did not report critical information on control mortality, water quality

parameters, or statistical methods, making compar ing effects between stud ies difficult. Studies

reporting only physiological responses to Pb exposure (e.g., reducti on of ALAD) are not

discussed here, as this topic was covered more completely in Section AX7.2.3.4. This section

provides a review of toxicity studies conducted with invertebra tes, fish, and other aquatic

organisms.

Invertebrates

Exposure of invertebrates to Pb can lead to adverse effects on reproduction, growth,

survival, and metabolism (Eisler, 2000). The fo llowing presents informa tion on the toxicity of

Pb to invertebrates in fresh and marine waters.

# AX7-184 Freshwater Invertebrates

Acute and chronic Pb toxicity data for fres hwater invertebrates are summarized in Table

AX7-2.4.1. As described in Section AX7.2.3.5, water ha rdness is a critical factor governing the

solubility, bioavailability, and ulti mately the toxicity of Pb. The acute and chronic toxicity of Pb

increases with decreasing water hardness as Pb becomes more soluble and bioavailable to

aquatic organisms. For example, Borgmann et al. (2005) examined the toxicity of 63 metals,

including Pb, to Hyalella azteca at two levels of water hardness (soft water hardness, 18 mg

CaCO 3 

# /L; hard water, 124 mg CaCO 3 

# /L). Lead was 23 times more acutely toxic to H. azteca in

soft water than hard water. Besser et al. (2005) found that acute toxicity to H. azteca was also

modified by water hardness.

At a mean pH of 7.97 in soft water (hardness (CaCO 3 

# ) = 71 mg/L) mortality was >50%

for H. azteca at a dissolved Pb concentration of 151 μg/L . The LOEC for surv ival in hard water

(hardness (CaCO 3 

# ) = 275 mg/L) at pH 8.27 was 192 μg/L as dissolved Pb and 466 μg/L as total

Pb. Both waterborne and dietary Pb were found to contribute to reduced survival of H. azteca

(Besser et al., 2005).

Exposure duration may also play an important role in Pb toxicity in some species.

For example, Kraak et al. (1994) reported that filtration in th e freshwater mussel Dreissena

polymorpha was adversely affected at significantly lower Pb concentrations over 10 weeks of

exposure than was the case after 48 h of exposure.

The influence of pH on lead toxicity in freshwater invertebrates varies between

invertebrate species. Over a 96- h exposure period, mortality increa sed with decreasing pH in the

bivalve Pisidium casertanum , while pH-independent mortality was reported for gastropod and

crustacean species under similar exposure conditions (Mackie, 1989). Cladocerans

( Ceriodaphnia dubia ), amphipods ( H. azteca ), and mayflies ( Leptophlebia marginata ) were also

more sensitive to Pb toxicity at lower pH levels (Schubauer-Berigan et al., 1993; Gerhardt,

1994). Lead was 100 times more toxic to the amphipod , Hyalella azteca , at a pH range of 5.0 to

6.0 (Mackie, 1989) than at a pH range of 7.0 to 8.5 (Schubauer-Berigan et al., 1993).

The physiology of an aquatic organism at cer tain life stages may be important when

determining the toxicity of metals to test orga nisms. For example, Bodar et al. (1989) exposed

early life stages of Daphnia magna to concentrations of Pb(NO 3 

# ) 2 

# . The test medium had a pH

of 8.3 ∀ 0.2, water hardness (CaCO 3 

# ) of 150 mg/L, and temperature of 20 ∀ 1 Ε C. Lead

# AX7-185Table AX7-2.4.1. Effects of Lead to Freshwater and Marine InvertebratesSpecies ChemicalEndpoint:Conc. (μg/L)*Duration ofExposureWater Chemistry Test Type - Effect ReferenceFreshwaterCladoceran(Ceriodaphnia dubia)leadchlorideLC50:280>2,700>2,70048 h pH:6–6.57–7.58–8.5Hardness: 280-300 mg/L CaCO3static-survival Schubauer-Beriganet al. (1993)Worm(Lumbriculus variegatus)leadchlorideLC50:>8,000>8,000>8,00096 h pH:6–6.57–7.58–8.5Hardness: 280-300 mg/L CaCO3static-survival Schubauer-Beriganet al. (1993)Amphipod(Hyalella azteca)leadchlorideLC50:<90>5,400>5,40096 h pH:6–6.57–7.58–8.5Hardness: 280-300 mg/L CaCO3static-survival Schubauer-Beriganet al. (1993)Amphipod(Hyalella azteca)leadchlorideLC50:27 (20.1-36.4)8 days Hardness130 mg/LpH 7.8-8.6renewal, 1-weekold amphipodsMacLean et al.(1996)Amphipod(Hyalella azteca)leadchlorideLC50:60 (53.6-67.3)8 days Hardness130 mg/LpH 7.8–8.6renewal, 10- to 16-week oldamphipodsMacLean et al.(1996)Mayfly(Leptophlebia marginata)leadchlorideLC50:1090(400-133200)96 h pH:4.5acute - survival Gerhardt (1994)Mayfly(Leptophlebia marginata)leadchlorideLC50:500096 h pH7.0acute - survival Gerhardt (1994)

# AX7-186Table AX7-2.4.1 (cont’d). Effects of Leadto Freshwater and Marine InvertebratesSpecies ChemicalEndpoint:Conc. (μg/L)*Duration ofExposure Water Chemistry TestType - Effect ReferenceAmphipod(Hyalella azteca)leadnitrateLC50:10211896 h pH:5.05.56.0acute-survival Mackie (1989)Bivalve(Pisidium compressum)leadnitrateLC50:38,00021,30011,40096 h pH:3.54.04.5acute- survival Mackie (1989)Bivalve(Pisidium casertanum)leadnitrateLC50:23,60023,50056,00096 h pH:3.54.04.5acute- survival Mackie (1989)Gastropod(Amnicola limosa)leadnitrateLC50:10,30020,6009,50096 h pH:3.54.04.5acute- survival Mackie (1989)Mussel(Dreissena polymorpha)leadnitrateEC50:3709148 h10 wkspH = 7.9; Hardness = 150 mgCaCO3/L; Temp = 15ΕCrenewal - filtration Kraak et al. (1994)Mussel(Dreissena polymorpha)leadnitrateLT50:35872 days pH = 7.9; Hardness = 150 mgCaCO3/L; Temp = 15ΕCrenewal - filtration Kraak et al. (1994)Amphipod(Hyalella azteca)leadnitrateLC50:4.8 (3.3 - 7.1)7 days pH = 7.37 - 8.27Hardness = 18 mg CaCO3/LDOC = 0.28 mg/Lrenewal - survival Borgmann et al.(2005)Amphipod(Hyalella azteca)leadnitrateLC50:113 (101 -126)7 days pH = 8.21 - 8.46Hardness = 124 mg CaCO3/L;DOC = 1.1 mg/Lrenewal - survival Borgmann et al.(2005)

# AX7-187Table AX7-2.4.1 (cont’d). Effects of Leadto Freshwater and Marine InvertebratesSpecies ChemicalEndpoint:Conc. (Φg/L)*Duration ofExposureWater Chemistry Test Type - Effect ReferenceMayfly(Leptophlebia marginata)leadchlorideLC50:1090 (95% C.I. =133.2)>500096 h pH = 4.5 - 6.5;DOC - 21.6 mg Cl!1;Cond = 7.0ΦS cm!1renewal - survival Gerhardt (1994)Cladoceran(D. magna)leadnitrateLC50:0.4548 hpH = 8.3∀0.2Hardness (CaCO3) = 150 mg/LTemp= 20ΕCstatic -embryogenesisBodar et al. (1989)Cladoceran(D. magna)leadchlorideNOEC:26012 to 21 d Not specifiedrenewal -reproductionEnserink et al.(1991)Cladoceran(D.magna)leadchlorideNOEC:27010 d Not specifiedrenewal - growth Enserink et al.(1991)Amphipod(Hyalella azteca)lead LOEC:(Dissolved Pb)192(Total Pb) 46696 h pH = 8.27Hardness (CaCO3) = 275 mg/LTemp = 21.1ΕCflow through -survivalBesser et al. (2005)Tubificid worm(Tubifex tubifex)leadnitrateEC50:237 (183–316)142 (107–184)24 h48 hpH = 7.5–7.7Hardness = 245 mg/LTemp = 29.5–31ΕCstatic -immobilizationKhangarot (1991)MarineCopepod(Amphiascus tenuiremis)lead LC50: sediment2462 μgmetal/drysediment96 hpH = 7.7∀0.1Dissolved O2-6.3∀0.3 mg/LSalinity – 32 pptHagopian-Schlekatet al. (2001)Bivalve(Mytilus galloprovincialis)leadnitrateEC50: 221(58.9–346.3)LOEC : 50artificial seawater embryogenesis Beiras andAlbentosa (2003)* - Brackets after effect concentration are 95% confidence intervals.

# AX7-188 concentrations of <100 mg/L had no impact on Daphnia egg development. The authors

suggested that this might due to the Daphnia egg structure, which consists of two layers: the

inner vitelline layer and outer chlorion layer. The chlorion layer in other species (e.g., rainbow

trout) is known to adsorb metals, thereby, prev enting ionic injury to the developing embryo.

Exposures to sediment-associated Pb can be toxic to sediment-dwelling organisms.

In freshwater sediments, 48- h exposure of water fleas ( Daphnia magna ) to 7000 mg Pb/kg dw

significantly reduced mobility, while exposur e to 13,400 mg Pb/kg dw for 24 h produced the

same effect (Dave, 1992a,b). Longer-term (i.e., 14-day) exposure of midges ( Chironomus

tentans ) to sediments containing 31,900 mg Pb /kg dw resulted in 100% mortality.

Marine Invertebrates

In estuarine environments, salinity is an im portant modifying factor to Pb toxicity.

Verslycke et al. (2003) exposed the estuarine mysid Neomysis integer to individual metals,

including Pb, and metal mixtures under ch anging salinity. Water temperature (20 ∀ 1 o 

# C) and

salinity were reported, although no other water qualit y parameters were available (e.g., pH, water

hardness). At a salinity of 5 l , the reported LC 50 

# for Pb was 1140 μg/L (95% CI: 840,

1440 μg/L). At an increased salinity of 25 l , the toxicity of lead wa s substantially reduced (LC 50



# = 4274 μg/L [3540, 5710 μg/L]) (Verslycke et al., 2003).

Sensitivity to Pb can also vary between genders in some aquatic organisms. For example,

Hagopian-Schlekat et al. (2001) examined the toxicity of Pb-chloride in sediment and sediment

pore water to female and male estuarine copepods Amphiascus tenuiremis . The reported LC 50



# for total lead was 2462 mg Pb/kg dw (95% CI: 2097, 2891 mg Pb/kg dw). Gender effects were

observed in that male copepods were more se nsitive (p = 0.038) to Pb than females as

determined by generalized linear model analysis.

Beiras and Albentosa (2003) examined th e inhibition of embryo development in

commercial bivalves Ruditapes decussatus and Mytilus galloprovincialis after exposure to

concentrations of Pb(NO 3 

# ) 2 

# in seawater. No water chemistry parameters other than temperature

were reported (test conducted at 20 o 

# C). An EC 50 

# range for R. decussatus was reported as 156 to

312 μg/L, as insufficient data were available to calculate the actual EC 50 

# . The lowest observable

effect concentration (LOEC) was 156 μg/L. For M. galloprovincialis , the EC 50 

# was 221 μg/L

(95% CI: 58.9, 346.3) while the LOEC was reported as 50 μg/L.

# AX7-189 Fish

The general symptoms of Pb t oxicity in fish include production of excess mucus, lordosis,

anemia, darkening of the dorsal tail region, degeneration of the ca udal fin, destruction of spinal

neurons, ALAD inhibition, growth inhibition, renal pathology, reproductive effects, growth

inhibition, and mortality (Eisler, 2000). Toxicity in fish ha s been closely correlated with

duration of Pb exposure and uptake (Eisler, 2000) . The following presents information on the

toxicity of Pb to fish in fresh and marine wa ters. Table AX7-2.4.2 summar izes the effects of Pb

on freshwater and marine fish.

Freshwater Fish

Many of the toxicity modifying factors described above and in Section AX7.2.3.5 (e.g.,

pH, DOC) for invertebrates are also important modifying factors for Pb toxicity to fish species.

The effects of pH on Pb bioavailability and subs equent toxicity have b een well-studied (Sayer

et al., 1989; Spry and Wiener, 1991; Schubauer-Be rigan et al., 1993; Stouthart et al., 1994;

MacDonald et al., 2002; Rogers and Wood, 2003). Schubauer-Ber igan et al. (1993) exposed

fathead minnow to Pb-chlorid e over 96 hours. The reported LC 50 

# ranged from 810 to

>5400 μg/L at pH 6 to 6.5 and pH 7 to 8.5, respectively.

Water hardness also has a strong influence on the effects of lead to fish. Chronic

exposure of rainbow trout fry to Pb in soft wate r resulted in spinal deformities at 71 to 146 μg/L

after 2 months of exposure (Sauter et al., 1976) or 13.2 to 27 μg/L (Davies and Everhart, 1973;

Davies et al., 1976), after 19 months of exposure. When exposed to Pb in hard water, only 0 and

10% of the trout ( Oncorhynchus mykiss ) developed spinal deformities at measured Pb

concentrations of 190 and 380 μg/L, respectively. In soft water, 44 and 97% of the trout

developed spinal deformities at concentrations of 31 and 62 μg/L, respectively (Davies et al.,

1976). The maximum acceptable toxicant concentra tion (MATC) for rainbow trout fry in soft

water was 4.1 to 7.6 μg/L (Davies et al., 1976) , while the MATC for brook trout was 58 to

119 μg/L (Holcombe et al., 1976). Histological re productive abnormalities were noted in mature

male rainbow trout at 10 μg/L Pb-nitrate (Ruby et al., 1993).

Schwartz et al. (2004) examin ed the influence of NOM on Pb toxicity to rainbow trout

exposed for 96 h in a static system. The pH of the exposure system ranged between 6.5 and 7.0,

temperature was maintained between 9 and 11 Ε C, and Pb was added as PbCl 2 

# . NOM from a

# AX7-190Table AX7-2.4.2. Effects of Pb toFreshwater and Marine FishSpecies ChemicalEndpoint:Conc. (Φg/L)Duration ofExposureWater Chemistry CommentsReferenceFreshwaterFathead minnow(Pimephales promelas)leadchlorideLC50:810>5,400>5,40096 h pH:6–6.57–7.58–8.5Hardness: 280-300mg/L CaCO3static, measured Schubauer-Beriganet al. (1993)Rainbow trout - maturemales(Oncorhynchus mykiss)leadnitrateReproductive effects:1012 days Hardness 128 mg/LCaCO3DecreasedspermatocytedevelopmentRuby et al. (1993)Fathead minnow(Pimephales promelas)leadacetateReproductive Effects:50029 days pH:7.5–8.5;Hardness 130 mg/LCaCO3;22–25ΕC(Pb 95% soluble)Fewer viable eggsproduced, testiculardamageWeber (1993)Rainbow trout – Juvenile(Oncorhynchus mykiss)leadnitrateLC50: 1000(800 - 1400)96 h pH:7.9–8.0DOC = 3 mg/LHardness (CaCO3) =140 mg/LFlow through - Survival Rogers and Wood(2003)Common carp(Cyprinus carpio)notreportedLC50:6.5 cm fish – 10303.5 cm fish – 30096 h pH:7.1Temperature–15ΕCOxygen sat. 6.4 mg/Lstatic-renewal -SurvivalAlam and Maughan(1995)

# AX7-191 number of U.S. rivers and lakes was th en added to the test system, and the LT 50 

# was reported.

NOM was found to reduce the toxic eff ects of Pb to rainbow trout.

Fish size is an important variable in determ ining the adverse effects of Pb. Alam and

Maughan (1995) exposed two different sizes of common carp ( Cyprinus carpio ) to Pb

concentrations to observed effects on carp mortality. Water chemistry parameters were reported

(pH = 7.1; temperature = 20 Ε C). Smaller fish (3.5 cm) were found to be more sensitive to Pb

than were larger fish (6.5 cm). The reported LC 50 

# s were 0.44 mg/L and 1.03 mg/L, respectively.

Marine Fish

There were no studies available that examined th e toxicity of Pb to marine fish species for

the time period examined (1986 to present). Howe ver, Eisler (2000) review ed available research

on Pb toxicity to marine species and reported studies done prior to 1986. Acute toxicity values

ranged from 50 μg/L to 300,000 μg/L in plaice ( Pleuronectes platessa ) exposed to organic and

inorganic forms of Pb (Eisler, 2000). Organol ead compounds (e.g., tetramet hyl Pb, tetraethyl Pb,

triethyl Pb, diethyl Pb) were generally more t oxic to plaice than inorganic Pb (Maddock and

Taylor, 1980).

Other Aquatic Biota

A paucity of data exist on the effects of Pb to growth, reproduc tion, and survival of

aquatic stages of frogs and turtles. Rice et al. (1999) exposed frog larvae ( Rana catesbeiana ) to

780 μg Pb/L and two oxygen concentrations (3.5 or 7.85 mg/L) for 7 days (Table AX7-2.4.3).

Exposure conditions included wate r hardness of 233 to 244 mg CaCO 3 

# /L, pH from 7.85 to 7.9,

and temperature at 23 Ε C. Frog larvae were found to displa y little to no activ ity in the low

oxygen and high Pb treatment. Hypoxia-like behavi or was exhibited in larvae exposed to both

low and high oxygen concentrations and high Pb. Therefore, larvae of R. catesbeiana showed

sensitivity to Pb and responded with hypoxia-like behavior. Additionally, the larvae in the Pb

treatment were found to have lost body mass relative to controls a nd the other treatments. Rice

et al. (1999) suggested that the decrease in mass likely indicated the beginning of a period of

reduced growth rate. Larvae exposed for l onger periods (>4 weeks) were smaller and

metamorphosed later compared to unexposed individuals.

# AX7-192Table AX7-2.4.3. Nonlethal Effects in AmphibiansSpecies ChemicalEndpoint:ConcentrationDuration ofExposureWater Chemistry CommentsReferenceFrogs(Rana ridibunda)lead nitrate Biochemical effects:14,000 μg/L30 days Not specified Hepatic ALAD decreased by90%Vogiatzis andLoumbourdis (1999)Frogs(Bufo arenarum)Mortality:16 mg Pb2+/L5 days Not specified Effects reported include erraticswimming, loss of equilibriumHerkovits and Perez-Coll(1991)Frogs(Rana catesbeiana)Hypoxia-likebehavior:780 μg/L7 days O2= 3.5-7.85 mg/LpH = 7.85-7.9Temp = 23ΕCCaCO3= 233-244mg/LLarvae usedRice et al. (1999)Turtle Hatchlings(Trachemys scripta)lead acetate NOEL: 100 μg/g(Survival andbehavior)4 weeks N/AExposure via single injection Burger et al. (1998)

# AX7-193 Herkovits and Pérez-Coll (1991) examined Pb toxicity to amphibian larvae ( Bufo

arenarum ). Larvae (n = 50) were exposed for up to 120 h at two Pb concentrations, 8 mg Pb 2+ 

# /L

and 16 mg Pb 2+ 

# /L. Relative to controls, the 8 mg Pb 2+ 

# /L treatment group exhibited 40%

mortality and the 16 mg Pb 2+ 

# /L group 60% mortality after 120 h (p < 0.05). The authors reported

behavioral effects, erratic swim ming, and loss of equilibrium during the tests, symptoms that are

consistent with the action of Pb on the central and peripheral nervous systems (Rice et al., 1999).

Behavior (i.e., righting, body tur nover, seeking cover), growth, and survival of hatchling

slider turtles ( Trachemys scripta ) exposed to Pb-acetate were i nvestigated in one study (Burger

et al., 1998). In the fi rst part of the study, 6-month-old ha tchlings received single Pb-acetate

injections at 50 or 100 μg/g body weight (bw). In the second part of the study, 3-week-old

turtles were injected once with doses of 250, 1000 or 2500 μg/g bw. There were no differences

in survival, growth, or behavior for hatchlings in the first st udy, however, several effects were

reported from the second part of the study at dos es in the range of 250 to 2,500 μg/g bw. As the

dose increased, so did the plastr on length (i.e., ventral section of the shell), carapace length, and

weight. The highest dose group had the lowest survival rate with an LD 50 

# of 500 μg/g bw.

Behavioral effects included slower times of ri ghting behavior and seeki ng cover. The authors

suggested a NOEL of 100 μg/g bw for slid er turtles for survival and behavior.

AX7.2.4.4 Recent Studies on Effect s of Lead on Decomposers

In this section, decomposers are defined as being bacteria and other microorganisms.

Many invertebrates are also poten tially considered decomposers, but the effects of Pb to

invertebrates have been described in previous sections. There we re no toxicity studies located on

the effects of Pb to aquatic decomposers in the time period of interest.

AX7.2.4.5 Summary

Lead in all its forms is known to cause adverse effects in aquatic organisms (Eisler, 2000).

Effects to algal growth have been observ ed at b concentrations ranging from 100 to

200,000 μg/L. Clinical signs of Pb toxicity in pl ants include the deformation and disintegration

of algae cells and a shortened exponential growth phase. Other effects of Pb include a blocking

of the pathways that lead to pigment synthesi s, thus affecting photos ynthesis, cell cycle and

division, and ultimately resulting in death. The toxicity of Pb to macrophyte growth has been

# AX7-194 studied using Spirodela polyrhiza

, Azolla pinnata , and Lemna gibba . Test durations ranged from

4 to 25 days and test concentrations ranged between 49.7 and 500,000 μg/L.

Waterborne Pb is highly toxic to aquatic organisms, with toxi city varying with the species

and life stage tested, duration of ex posure, form of Pb tested, and water quality characteristics.

Among the species tested, aquatic invertebrates, such as amphipods and water fleas, were the

most sensitive to the effects of Pb, with adve rse effects being reported as low as 0.45 μg/L.

Effects concentrations for aquatic invertebra tes were found to range from 0.45 to 8000 μg/L.

Freshwater fish demonstrated adverse effects at concentrations ranging from 10 to >5400 μg/L,

depending generally upon water qual ity parameters. Amphibians tend to be relatively Pb tolerant

(Eisler, 2000); however, they may exhibit decrea sed enzyme activity (e.g., ALAD reduction) and

changes in behavior (e.g., hypoxia response behavior). Lead tends to be more toxic with longerterm exposures.

The primary focus of this section was on eff ects at the individual level of organization.

This narrow focus is primarily due to a lack of information on the effects of lead on higher levels

of organization (e.g., populations, communities, and ecosystems). The impact of lead at higher

levels of biological organization should be cons idered in future reviews of lead toxicity.

In considering these higher levels of organiza tion, cause-effect models and relationships that

examine the roles of life history strategy and optimal foraging theory, community processes and

associated theory, and ecosystem processes and th e influences of redundanc y/interactions should

be taken into account.



# AX7.2.5 Effects of Lead on Natural Aquatic Ecosystems

Introduction

As discussed previously, lead exposure may adve rsely affect organisms at different levels

of organization, i.e., individual organisms, popula tions, communities, or ecosystems. Generally,

however, there is insufficient information availabl e for single materials in controlled studies to

permit evaluation of specific impacts on higher levels of organizati on (beyond the individual

organism). Potential effects at the population leve l or higher are, of necessity, extrapolated from

individual level studies. Av ailable population, community, or ecosystem level studies are

typically conducted at sites that have been c ontaminated or adversely affected by multiple

stressors (several chemicals alone or combined with physical or bi ological stressors). Therefore,

# AX7-195 the best documented links between lead and effects on the environment are with effects on

individual organisms.

This section discusses the e ffects of Pb on natural aquati c ecosystems. Such effects

include changes in species composition and richne ss, ecosystem function, and energy flow due to

Pb stress. The format of this section genera lly follows a conceptual framework for discussing

the effects of a stressor such as Pb on an ecosy stem. This conceptual framework was developed

by the EPA Science Advisory Board (Young and Sa nzone, 2002). The essential attributes used

to describe ecological condition include lands cape condition, biotic condition, chemical and

physical characteristics, ecological proce sses, hydrology and geomorphology and natural

disturbance regimes. The majority of the pub lished literature pertaining to Pb and aquatic

ecosystems focuses on the biotic co ndition, one of several essential a ttributes of an ecosystem as

described in Young and Sanzone (2002). For the biotic condition, the SAB framework identifies

community extent, community composition, tr ophic structure, community dynamics, and

physical structure as factors for assessing ecosy stem health. Other factors for assessing the

biotic condition such as effect s of Pb on organs, species, popula tions, and organism conditions

(e.g., physiological status) were discussed in Sections AX7.2.3 and AX7.2.4.

For natural aquatic ecosystems, the focus of study in the ge neral literature has been on

evaluating ecological stress where th e sources of Pb were from ur ban and mining effluents rather

than atmospheric deposition (Poulton et al., 1995; Deacon et al., 2001; Mucha et al., 2003). The

atmospheric deposition of Pb in remote lakes has been evaluated; however, the direct effects of

Pb on aquatic ecosystems was not evaluated in many cases (Larsen, 1983; Köck et al., 1996;

Allen-Gil et al., 1997; Outridge, 1999; Lotter et al., 2002). In othe r studies, although Pb

deposition was studied, the effect s of acid deposition on aquatic life were th e focus of the study

and perceived to be more relevant (Mannio, 2001; Nyberg et al., 2001). Finally, the effects of

Pb, other metals, and acidification on phytoplan kton have only been inferred based on the

paleolimnolical record (Tolonen and Jaakkola, 1983; Rybak et al., 1989). The statistical

methods used when evaluating the effects of Pb on aquatic ecosystems are important, as more

than one variable may be related to the obser ved effect. Studied va riables include water

hardness, pH, temperature, and physical factors such as embeddedness, dominant substrate, and

velocity. In most cases, single va riable statistical techniques were used to evaluate the data.

# AX7-196 However, in other cases multivariate techniques we re used. Therefore, where appropriate, some

detail on the statistical met hods used is presented.

Although most of the available studies discus sed in this section focus on the biotic

condition, one case study examining multiple com ponents of the EPA conceptual framework is

also included. The remainder of th is section describes the effects of Pb on the biotic condition.

AX7.2.5.1 Case Study: Coeur d’Alene River Watershed

The Coeur d’Alene River watershed is an area of Idaho impacted by Pb and other metals

from historic mining waste releases. Mare t et al. (2003) examined several ecological

components to determine any negative associations with metals and the watershed communities.

The variables examined and associated ecologi cal conditions are presented in Table AX7-2.5.1.

In addition to measurements of non-metal va riables (e.g., dissolved oxygen levels, water

temperature and pH, embeddedness), Cd, Pb, and Zn le vels were also compared in affected sites

versus reference sites.

Some of the above non-metal variables are im portant to macroinvertebrate communities.

For example, a stream with highly embedded subs trate can have a lower number of individuals

within a species or a different species compos ition compared to a stream with less embeddedness

(Waters, 1995). Macroinvertebrates from the Ephe meroptera (mayflies), Pl ecoptera (stoneflies),

and Trichoptera (caddisflies) (EPT ) group inhabit the surf ace of cobble and the interstitial spaces

between and underneath cobble. When substrate is embedded, these inters titial spaces are filled,

leaving less habitat space for EP T taxa. In another example, water temperature is important;

some macroinvertebrates (e.g., ston eflies) are usually only found in cooler water (Harper and

Stewart, 1984).

Of the variables examined only metal concentrations, mine densit y, site elevation, and

water temperature were significan tly different between reference and mine-affected sites.

A Mann-Whitney t-test was used to evaluate statistical differences between reference and

test sites for physical and water quality parameters , while Spearman’s rank correlation matrices

were used to compare all possible response and expl anatory variables. Lead concentrations were

significantly correlated with th e number of mines in proxim ity to the watershed. Lead

concentrations in sediment and water were strongly correlated to Pb levels in whole caddisflies,

r 2 

# = 0.90 and 0.63, respectively. Furthermore, mine de nsity was significantly correlated to Pb in

# AX7-197 Table AX7-2.5.1. Ecological Attributed Studies by Maret et al. (2003)

in the Coeur d’Alene Watershed

Ecological Attribute Subcategory Measure



# Landscape condition Areal extent
landscape pattern Basin area (km 2 

# ) Production mine density/km 2



# Biotic Condition Organism condition
population structure/ dynamics Caddisfly tissue concentrations (mg/kg)

Number of EPT taxa Density of EPT individuals (no./m 2 

# )

Chemical/physical

characteristics Chemical/physical

parameters Dissolved oxygen (mg/L)
Specific conductance (μS/cm)

Water temperature (E Ε C)
pH Water hardness (mg/L)

Total NO 3 

# (mg/L) Total P (mg/L)

Dissolved NH 3 

# (mg/L) Sediment Cd, Pb, Zn (mg/kg) Dissolved Cd, Pb, Zn in water (mg/L)

Ecological processes — None measured

Hydrology/geomorphology Channel morphology

and distribution Site elevation (m)
Stream gradient (%)
Stream discharge (m 3 

# /s)
Stream width (m)
Stream depth (m)
Open canopy (%) Stream velocity (m/s)
Embeddedness (%)
Dominant substrate (mm)

Natural disturbance regimes — None measured



# tissue, r 2 

# = 0.64. Although temperature was signifi cantly different between reference and

mine-affected sites, temperature conditions were concluded to be non-lim iting to aquatic life.

For example, reference and mine-affected sites ha d at least 15 and 13 obligate cold-water taxa,

respectively.

A significant negative correlation between Pb in the water column (0.5 to 30 μg/L

dissolved) and total taxa richness , EPT taxa richness, and the num ber of metal-sensitive mayfly

# AX7-198 species was observed. Similar, significant negati ve correlations were found between sediment

Pb levels (132 to 6252 μg/g) and the same macr oinvertebrate community metrics and caddisfly

tissue levels. Negative correla tions were also found between Cd and Zn in the water and

sediment and the macroinvertebrate community metr ics. In an analysis of cumulative toxicity,

Pb was judged to be the most significant metal in sediment related to the cumulative toxicity

measured. This study provided multiple lines of evidence (i.e., mine density, metal

concentrations, bioaccumulation in caddisfly ti ssue and benthic invertebrate assemblage

structure) of the negative impacts of mining in the Coeur d’Alene River, suggesting that Pb (and

other metals) were primary contributors to th e effects observed in the Coeur d’Alene River

watershed (Maret et al., 2003).

AX7.2.5.2 Biotic Condition

In an evaluation of the biotic condition, the SAB framework described by Young and

Sanzone (2002) identifies co mmunity extent, community co mposition, trophic structure,

community dynamics, and physical structure as essential ecological at tributes for assessing

ecosystem health. The following two sections describe the effects of Pb on community

composition, community dynamics, and trophic struct ure. To date, no available studies were

located on the effects of Pb on physical struct ure (e.g., change in ripa rian tree canopy height,

ecosystem succession).

Ecosystems and Communities, Community Composition

To measure community composition, an invent ory of the species/taxa found in the

ecological system must be conducted. Accord ing the SAB framework, useful measures of

composition include the total number of species or taxonomic units, their relative abundance,

presence and abundance of native and non-native species, and information on the presence and

abundance of focal or special interest speci es (Young and Sanzone, 2002). Focal or special

species of interest can be those that play a critic al role in ecosystem processes such as flows of

materials or energy within complex food- webs (Young and Sanzone, 2002). Community

composition as assessed in Pb studies has included the following measures.

# AX7-199 • Changes in energy flow or nutrient cycling:

o Increased or decreased respiration or biomass

o Increased or decreased turnover/cycling of nutrients

• Changes in community structure:

o Reduced species abundance (i.e., the total num ber of individuals of a species within
a given area or community)

o Reduced species richness (i.e., the numb er of different species present in
a community)

o Reduced species diversity (i.e., a measur e of both species abundance and species
richness)

Investigators have evaluated the effects of Pb on aquatic communities through microcosm

and mesocosm studies in natural aquatic systems. Field studies in the ge neral literature have

focused on natural systems that were affected by metal stress from various anthropogenic

sources. In most of those natural systems, the sources evaluated were from direct mining waste

inputs, rather than atmospheric deposition, of Pb. Studies published since the 1986 Lead AQCD

(U.S. Environmental Protection Agency, 1986a) that describe the effects of Pb on natural aquatic

ecosystems are presented below and summarized in Table AX7-2.5.2. Studies included here

evaluated the effects of Pb on watersheds, landscapes, aquatic ecosystems, aquatic communities,

biodiversity, lakes, rivers, streams, estu aries, wetlands, and species interaction.

Aquatic Microcosm Studies

The examination of simulated aquatic ecosy stems (i.e., microcosms) provides limited

information on the effects of pollutants on natural systems. Microcosm studies typically focus

on only a few aspects of the natural system a nd do not incorporate a ll of the ecological,

chemical, or biological interactions. Nevert heless, a few microcos m studies have been

conducted that indicate potential e ffects of Pb on the community structure of aquatic ecosystems.

Fernandez-Leborans and Antonio- García (1988) evaluated the effect of Pb on a natural

community of freshwater protozoans in simula ted aquatic ecosystems and found a reduction in

the abundance and composition of protozoan specie s with increasing Pb concentrations (0.05 to

1.0 mg/L) compared to controls. Studies with marine protozoan communities in laboratory

microcosms indicated that waterborne Pb expos ure reduced protozoan abundance, biomass, and

# AX7-200Table AX7-2.5.2. Essential Ecological Attributes for Natural Aquatic Ecosystems Affected by LeadCategory SpeciesConditionMeasuresExposureMediumLocationExposureConcentrationsOtherMetalsPresentReferenceBiotic ConditionEcosystems andCommunities-CommunityCompositionProtozoan community Reduced speciesabundance anddiversityMarine water Laboratory microcosm 0.02– 0.05 mg/L N Fernandez-Leborans andNovillo (1992)ProtozoancommunityReducedspeciesabundanceFreshwaterwaterLaboratory microcosm 0.05–1 mg/LN Fernandez-Leborans andAntonio-García(1988)Protist community Reduced speciesabundance anddiversityMarine water Laboratory microcosm 1 mg/LN Fernandez-Leborans andNovillo (1994)Meiofauna community Reduced abundance MarinesedimentLaboratory microcosm 177 mg/kg dw Y Millward et al.(2001)Algal community Increased respiration Freshwater Domestic waterstabilization pond25–80 mg/L? Jayaraj et al. (1992)AlgalcommunityDecreasedprimaryproductivityFreshwater Sharana BasaveshwaraTank, India6–32 mg/L? Jayaraj et al. (1992)Meiobenthiccommunity(primarily nematodes)Reduced speciesabundanceNo effect onabundanceMarinesedimentLaboratory microcosm 1343 mg/kg dw1580 mg/kg dwN Austen andMcEvoy (1997)

# AX7-201Table AX7-2.5.2 (cont’d). Essential Ecological Attributesfor Natural Aquatic Ecosystems Affected by LeadCategory SpeciesConditionMeasuresExposureMedium LocationExposureConcentrationsOtherMetalsPresent ReferenceMacroinvertebratecommunityLower totalabundance, decreasedtaxa, and EPTrichness, largerpercentage of tolerantspecies of benthicmacroinvertebrates.Freshwaterand sedimentMining sites in theUpper Colorado Basin<0.001–0.02 mg/L145-850 mg/kg dw(<63 μM fraction)Y Deacon et al.(2001); Mize andDeacon (2002)MacroinvertebratecommunityNegatively correlatedwith species richnessand diversity indicesEstuarysedimentDouro Estuary, Portugal 0.25–192 mg/kg dw Y Mucha et al. (2003)MacroinvertebratecommunityReduced speciesabundanceFreshwatersedimentRiver Ill and tributaries,France1–16 mg/kg dw Y Rosso et al. (1994)Fish,crustaceanandmacroinvertebratecommunityCorrelation withchanges in speciesabundance anddistributionMarineSedimentSpencer Gulf, SouthAustralia156–5270 mg/kgdwY Ward and Young(1982);Ward andHutchings (1996)Chironomid community Reduced chironomidrichnessWholeorganismresidueNew Brunswick, Canada 40.3–1,387 mg/kgdw (periphyton)1.6–131 mg/kg dw(chironomid tissue)Y Swansburg et al.(2002)MacroinvertebratecommunityLead in tissuesnegatively correlatedwith taxa richness,EPT richness,chironomid richness,and species density.WholeorganismresidueClark Fork River, MT 32.2–67.1 mg/kgdwY Poulton et al.(1995)MacroinvertebratecommunityLead in tissuesnegatively correlatedwith EPT richnessand abundance.BiofilmresiduesBoulder River, MT 32–1540 mg/kg dw Y Rhea et al. (2004)

# AX7-202Table AX7-2.5.2 (cont’d). Essential Ecological Attributesfor Natural Aquatic Ecosystems Affected by LeadCategorySpeciesCondition MeasuresExposureMediumLocationExposureConcentrationsOtherMetalsPresentReferenceMacroinvertebrateCommunityLead in tissues andsediment not correlatedto diversity andrichnessSedimentand wholeorganismresidueAquashicola Creektributaries, Palmerton,PA7.5–59.5 mg/kg dw(sediment)0.25-6.03 mg/kg dw(macroinvertebrates)Y Carline and Jobsis(1993)Fish Community Lead in tissues andsediment not correlatedto diversity andrichnessSedimentand wholeorganismresidueAquashicola Creektributaries, Palmerton,PA7.5–59.5 mg/kg dw(sediment)0.1-0.86 mg/kg dw(fish)Y Carline and Jobsis(1993)Ecosystems andCommunities-CommunityDynamics andTrophic StructureSnails and tadpoles Lead affected predator-prey interactionsSediment Outdoor mini-ecosystemsNot citedY Lefcort et al. (1999)Snails and caddisflies No avoidance ofpredator by snail.Caddisfly did respondto predatorWater Field microcosm forsnail; in-streamdisturbance forcaddisfly27.7–277.6 mg/kgdw (snail tissue)223–13,507 mg/kgdw (caddisfly tissue)Y Lefcort et al. (2000)Fathead minnow Feeding behavioralteredWater Laboratory microcosm0.5–1.0 mg/LN Weber (1996)American toad No avoidance of lead Water Laboratory microcosm 0.5–1.0 mg/LN Steele et al. (1991)Mummichog Feedingbehavioraltered and predatoravoidance affectedWater Laboratory 0.3–1.0 mg/LN Weis and Weis(1998)

# AX7-203 diversity at concentrations of 0.02 to 1.0 mg/L Pb (Fernandez-Leborans and Novillo,

1992, 1994).

Austen and McEvoy (1997) studied the eff ects of Pb on an estuarine meiobenthic

community (mainly nematodes) in a microcos m setting using sediment samples collected

offshore from England. A multivariate analysis ofsimilarities (ANOSIM) test with square roottransformed data was used to evaluate differen ces between treatments and controls. Lead was

found to significantly affect species abundance at 1343 mg/kg dw relative to a control at

56 mg/kg dw, but no significant adverse effects were observed at the highest dose tested,

1580 mg/kg dw. The authors did not attempt to explain why the 1580 mg/kg dw dose was not

significant while the 1343 mg/kg dw dose was. N one of the Pb exposures were significantly

different than the controls based on separate univariate tests of abundance, richness, and

diversity. There were no other confounding metals in the Pb tests, as the experiments were with

a single metal dose. In one other mesocosm st udy, the effects of a mixture of metals (Cu, Cd,

Pb, Hg, and Zn) on a salt marsh meiofaunal comm unity were evaluated (Millward et al., 2001).

After 30-days exposure, significant reduc tions in copepod, gastropod, and bivalve

abundances were observed at the highest Pb e xposure concentration, 177 mg/kg dw. Ostracods

and nematodes were not affected. The authors be lieved that the response of the meiofauna taxa

to metals was in part due to the various feedi ng strategies in that de posit feeders were most

affected.

Natural Aquatic Ecosystem Studies

Lead stress in aquatic ecosystems has also been evaluated in natural communities.

Studies examining community-sca le endpoints, however, are comp lex, and interpretation can be

confounded by the variability found in natural syst ems and the presence of multiple stressors.

Natural systems frequently contain multiple metals, making it difficult to attribute observed

adverse effects to single metals. For example, macroinvertebrate communities have been widely

studied with respect to metals contaminati on and community composition and species richness

(Winner et al., 1980; Chadwick et al., 1986; Clements, 1994). In these studies, multiple metals

are evaluated and correlations between observed community level effects are ascertained. The

results often indicate a correlation between the pr esence of one or more metals (or total metals)

and the negative effects observed. While, corr elation may imply a relationship between two

# AX7-204 variables, it does not imply causa tion of effects. The following studies suggest an association

between Pb concentration and an alteration of community structure and function (see summary

in Table AX7-2.6.2):

Reduced Primary Productivity and Respiration

Jayaraj et al. (1992) examined the effects of Pb on primary productivity and respiration in

an algal community of two water bodies. Concentr ations of Pb in water (6 to 80 mg/L) were

found to significantly reduce primary productivity and increase respiration. The authors

suggested that increased respirat ion indicated a greater tolerance to or adaptive mechanisms of

the resident heterotrophs to cope with lead stress.

Alterations of Community Structure

Deacon et al. (2001) studied a macroinvertebra te community in mine-affected waters of

Colorado. Initially, transplant ed bryophytes were used to assess whether metals could

bioaccumulate at various mine-affected and unaffected sites (Deacon et al., 2001; Mize and

Deacon, 2002). Lead was bioaccumulated by the bryophytes, and median tissue concentrations

at mine-affected sites (34 to 299 μ g/g dw) were higher than at reference sites (2.5 to 14.7 μ g/g

dw). Lead concentrations in surface water and sediment ranged from <0.001 to 0.02 mg/L and

145 to 850 mg/kg dw (<63 μm fraction), respectively. The same sites were also evaluated for the

effects of various metals on macroinvertebrate communities. Values of total abundance, taxa

richness, mayfly, and stonefly abundance were redu ced at mining sites. Lead levels along with

Cd, Cu, and Zn were correlated with re duced abundance and diversity indices.

Macrobenthic communities studied in a Portuguese estuary were affected by Pb at a range

from 0.25 to 192 mg/kg dw (Mucha et al., 2003). Species richness was decr eased in areas with

increased Pb concentrations in the sediment. Interpretation of Pb effects was complicated by

other non-metal stressors, namely sediment pa rticle size and organic matter content.

Furthermore, other metals were present (e.g., Al , Cu, Cr, Mn, Zn) and may have affected the

community (Mucha et al., 2003).

The effects of Pb on oligochaetes in the I ll River and its tributaries in France were

evaluated by Rosso et al. (1994). Lead in sediment (5 to 16 μ g/g dw at affected sites) was

positively correlated to the abundance of the oligochaete, Nais sp., and negatively correlated to

# AX7-205 Tubificidae abundance. Lead was the only metal that was positively correlated to Nais species,

while other metals were negatively correlate d to Tubificidae (Ro sso et al., 1994).

The effects of metals and particle size on structuring epibenthic sea grass fauna (fish,

mollusks, crustaceans, and polychaetes) was eval uated near a Pb smelter in South Australia

(Ward and Young, 1982; Ward and Hutchings, 1996). Effluent from the smelter was the primary

source of Pb and other metal contamination. Sp ecies richness and composition were evaluated

near the Pb smelter along with metal concentrations in sediment. Lead levels in sediment (up to

5270 mg/kg dw) correlated with ne gative effects on species ric hness and composition, while the

other metals evaluated had similar correlations. Therefore, Pb alone could not be identified as

the sole metal causing stress.

Tissue Bioaccumulation Associated with Alterations of Community Structure

Several studies have examined the bioaccumu lation of lead in a quatic systems with

indices of community structure and function. A focused study on changes in Chironomidae

community composition in relation to metal mine s (New Brunswick, Canada) identified changes

in Chironomidae richness (Swansburg et al., 2002) . Lead was not detected (detection limit not

given for any matrix) in the wate r column at any site. However, Pb levels in periphyton were

significantly higher at mining sites (40.3 to 1387 mg /kg dw) compared to reference sites (not

detected [ND], 33.3 mg/kg dw). Furthermore, Pb in chironomids was significantly higher at

mine-affected sites (1.6 to 131 mg/kg dw) compar ed to reference sites (ND, 10.2 mg/kg dw).

The concentrations in biota indicate that Pb is mobile and available to the aquatic community

even though water concentrations were undetectab le. Chironomidae richness was reduced at the

sites receiving mining effluent c ontaining Pb, Cd, Cu, and Zn.

In another study, macroinvertebra te lead tissue concentrations (32.2 to 67.1 mg/kg dw at

affected sites) collected from the Clark Fork River, Montana correlated negatively with total

richness, EPT richness, and dens ity (Poulton et al., 1995). Mean Pb levels were as high as

67.1 mg/kg dw at sites most affected by lead. However, other metals, including Cd, Cu, and Zn,

also were negatively correlated with total richness and EPT richness. Therefore, attribution of

the observed effects to Pb is difficult, as other metals may be contributing factors.

In Montana, the potential effects of metals on macroinvertebrate communities in the

Boulder River watershed were evaluated (Rhea et al., 2004). Similar to the approach taken by

# AX7-206 Poulton et al. (1995), the effects on richness and abundance of EPT taxa were compared to metal

concentrations in tissue (i.e., biofilm and macroi nvertebrates). Lead levels in biofilm (32 to

1540 mg/kg dw) were significantly correlated with habitat scores and macroinvertebrate indices

(e.g., EPT taxa). However, macroinvertebrate tiss ue Pb levels were not significantly correlated

with macroinvertebrate community level metrics. As with most natural systems with potential

mine impacts, other metals also correlated with community level effects. However, the authors

indicated that Pb concentrations in biofilm appeared to have the most significant impact on

macroinvertebrate metrics.

A detailed investigation of sediment, macr oinvertebrates, and fish was conducted for

tributaries in the Aquashicola Creek watershed near a former zinc smelter in Palmerton, PA

(Carline and Jobsis, 1993). The smelter deposit ed large amounts of Cd, Cu, Pb, and Zn on the

surrounding landscape during its operation from 1898 to 1980. The goal of the study was to

evaluate if there was a trend in the metal levels in sediment, macroinvertebrate and fish tissue,

and community indices going away from the sme lter. Sites were chosen, from 7.8 to 24.6 km

from the smelter. There were no clear associat ions between proximity to the smelter and Pb

levels in sediment, macroinvertebrate tissue, and fish tissue. Furthermore, there were no

associations between proximity to the smelter and macroinvertebrate and fish diversity and

richness. The authors suggested th at the transport of metals in the watershed has decreased since

the smelter ceased operation, and thereby no effects were observed.

Ecosystems and Communities, Community Dynamics, and Trophic Structure

As described in the SAB framework, community dynamics include interspecies

interactions such as competition, pred ation, and succession (Young and Sanzone, 2002).

Measures of biotic interacti ons (e.g., levels of seed disper sal, prevalence of disease in

populations of focal species) provide important information about community condition. If the

community dynamics are disrupted, then the trophic structure may also be disrupted. According

to the SAB framework, trophic structure refers to the distribution of sp ecies/taxa and functional

groups across trophic levels. Measures of trophic structure include food web complexity and the

presence/absence of top predators or dominant herbivores. Theref ore, this section discusses how

aquatic species interactions can be affected by Pb. Examples of species interactions can include:

# AX7-207 • Predator-prey interactions (e.g., reduced avoidance of predators)

• Prey consumption rate (e.g., incr ease or decrease in feeding)

• Species competition (e.g., interference with another species, increased aggressive
behavior)

• Species tolerance/sensitivity (e.g., the emergence of a dominant species due to contaminant tolerance or sensitivity)

Species interactions are highly relevant to a discussion about the effects of Pb on natural

aquatic ecosystems, because effects on species interactions could potentially affect ecosystem

function and diversity. Some examples of Pb induced changes in species interactions are

presented below (see summary in Table AX7-2.5.2).

Predator-prey Interactions

Lefcort et al. (1999) examined the competitive and predator avoidance behaviors of snails

and tadpoles in outdoor mini-ecosystems with se diment from a metals-contaminated Superfund

site (i.e., Pb, Zn, Cd). Previous investigations of aquatic invertebrates an d vertebrates yielded Pb

tissue concentrations of 9 to 3800 mg/kg dw and 0.3 to 55 mg/kg dw, respectively. Several

species interactions were studied in the pr esence of metal-contaminated sediment:

Snails and tadpoles have similar dietary behavi ors. Thus, when placed in the same habitat

they will compete for the same food items and ne gatively affect one another. However, when

tadpoles exposed to a predator (i.e., through biweekly additions of 20 mL of water from tanks

housing sunfish—10 mL from sunfish-fed snails, 10 mL from sunfish-fed tadpoles) were placed

with snails, the tadpoles reduced sediment inge stion, while snails incr eased ingestion. Thus,

snails were exposed to greater quant ities of metals in sediment.

In an uncontaminated environment, snail r ecruitment (i.e., reproduction) was reduced in

the presence of tadpoles. The addition of tadpol es increased the competition for food in the form

of floating algae and the snails switched to feeding on algae that grew on the sediment. This

decrease was due to competition alone. The eff ects on snail recruitment were even higher when

tadpoles, the influence of a predator (i.e., sunfish extract), and metals in the sediment were all

present. However, the predator effect was indi rect in that the tadpoles hid in the algal mats

forcing the snails to feed primarily on the be nthic algae that grew on the sediment with high

# AX7-208 metal levels. Furthermore, although not significa nt, Pb levels in snails were higher when

tadpoles and sunfish extract were present than when only metals in the sediment were present.

Finally, snail predator avoidance was assesse d. Snails (control a nd lead-exposed) were

stimulated with a predator indica tor (i.e., crushed snails and an ex tract of crushed snail). Control

snails changed behaviors in the presence of the pr edator indicator, while exposed snails did not

alter their behavior. The author s suggested that metal exposure caused behavioral changes that

alter competitive interactions and the perception of predators by the snails. Thus, Pb may affect

the predator avoidance response of snails.

In further study, Lefcort et al. (2000) examined the predator avoidance behaviors of snails

and caddisflies. In separate experiments, the avoidance behavior of the snail, Physella

columbiana , and four caddisfly genera ( Agrypnia, Hydropsyche, Arctopsyche, Neothremma )

were evaluated. The snails were collected fr om reference lakes and lakes downstream of the

Bunker Hill Superfund site. The snails from the affected lakes generally had higher cadmium,

Pb, and zinc tissue levels implyi ng previous exposure to these me tals. Snail predator avoidance

behavior was tested by exposure to crushed snail extract. Snails from the affected lakes did not

reduce their activity when exposed to the snail extract, implying a reduced predator avoidance.

The lack of response may make the snails at th e affected lakes more pr one to predation.

The caddisflies were evaluated at 36 sites from six different st reams. As with the snails,

the caddisflies from the affected streams had higher cadmium, Pb and zinc tissue levels. The

time for caddisfly larvae to re spond (i.e., how long immobile) to disturbance (i.e., lifted from

water for 3 seconds and moved to a new locat ion) was evaluated. There was no correlation

between tissue metal level and any response vari able (Lefcort et al., 2000). Therefore, the

authors concluded that preexposure to metals did not reduce predator avoidance for caddisflies.

Weber (1996) examined juvenile fathead minnows exposed to 0, 0.5, or 1.0 ppm Pb in

water during a 2-week preexposure and 2-week testi ng period (4 weeks total exposure). Feeding

behavior was evaluated by presenting tw o prey sizes (2-day-old and 7-day-old Daphnia magna ).

Control fish began switching from larger, more difficult-to-capture 7-day-old daphnids to

smaller, easier-to-catch 2-day-old prey by day 3. Lead-exposed fish displayed significant

switching at day 3 (at 0.5 ppm) or day 10 (at 1.0 ppm). Thus, expos ure to Pb delayed the altering

of prey size choices to less energetically costly prey.

# AX7-209 Lefcort et al. (1998) ex posed spotted frogs ( Rana luteiventris ) to 0.05 to 50 ppm Pb in

water for 3 weeks. High levels of Pb reduced the fright response of tadpoles; suggesting a

reduced avoidance of predators.

Bullfrog larvae exposed to Pb in water (0.78 mg/L) and high or low dissolved oxygen

were monitored for respiratory surfacing behavior (Rice et al., 1999). Larvae had a significantly

increased number of trips to the water surface re gardless of oxygen content. Thus, the authors

suggest that Pb may affect oxygen uptake such that larvae are under greater predation pressure

due to increased time spent at the surface.

Weis and Weis (1998) evaluated the e ffect of Pb expos ure on mummichog ( Fundulus

heteroclitus ) larvae prey capture rate, swimming behavior, and predator avoidance. Prey capture

rates were affected after 4 weeks exposure at 1.0 mg Pb/L. The larvae were also more

vulnerable to predation by grass shrimp ( Palaemonetes pugio ) at 1.0 mg Pb/L. Finally, the

swimming behavior of mummichog larvae was affect ed at 0.3 and 1.0 mg Pb/L. Once the larvae

were no longer exposed to Pb, they recovered their ability to capture prey and avoid predators.

Clearly, exposure to Pb does affect the predator -prey interactions and th e ability of prey to

avoid predators. The effect of Pb on these ecol ogical functions may alter community dynamics.

AX7.2.5.3 Summary

The effects of Pb have primarily been studied in instances of point source pollution rather

than area-wide atmospheric deposition; thus, the effects of atmos pheric Pb on ecological

condition remains to be defined. The evaluation of point source Pb within the EPA Ecological

Condition Framework has been examined primar ily in relation to bi otic conditions. The

available literature focuses on st udies describing the effects of Pb in natural aquatic ecosystems

with regard to community composition and species interactions. The effect s of Pb on the biotic

condition of natural aquatic systems can be summarize d as follows: there is a paucity of data in

the general literature that explores the effects of Pb in conjunction with all or several of the

various components of ecological condition as de fined by the EPA. However, numerous studies

are available associating the presence of Pb with effects on biotic conditions.

In simulated microcosms or natural systems, environmental exposure to Pb in water and

sediment has been shown to affect energy fl ow and nutrient cycling and benthic community

structure. In field studies, Pb contamination has been shown to significantly alter the aquatic

# AX7-210 environment through bioaccumulation and alterati ons of community structure and function.

Exposure to Pb in laboratory studies and simu lated ecosystems may alter species competitive

behaviors, predator-prey interact ions, and contaminant avoidance be haviors. Alteration of these

interactions may have negative effects on speci es abundance and community structure. In

natural aquatic ecosystems, Pb is often found coexisting with other metals and other stressors.

Thus, understanding the effects of Pb in natural systems is cha llenging given that observed

effects may be due to cumulative toxicity from multiple stressors.

# AX7-211 

# REFERENCES

Abd-Elfattah, A.; Wada, K. (1981) Adsorption of lead, copper, zinc, cobalt, and cadmium by soils that differ in cation-exchange materials. J. Soil Sci. 32: 271-283.
AbdAllah, A. T.; Moustafa, M. A. (2002) Accumulation of lead and cadmium in the marine prosobranch Nerita

saxtilis , chemical analysis, light and electron mi croscopy. Environ. Pollut. 116: 185-191. Acosta-Martinez, V.; Tabatabai, M. A. (2000) Arylamid ase activity of soils: effect of trace elements and
relationships to soil properties and activities of amidohydrolases. Soil Biol. Biochem. 33: 17-23.

Adam, M. S.; Abdel-Basset, R. (1990) Effect of lead nitrate and lead acetate on the growth and some metabolic processes of Scenedesmus obliquus . Acta Hydrobiol. 32: 93-99.
Adgate, J. L.; Willis, R. D.; Buckley, T. J.; Chow, J. C.; Watson, J. G.; Rhoads , G. G.; Lioy, P. J. (1998) Chemical mass balance source apportionment of lead in house dust. Environ. Sci. Technol. 32: 108-114.
Agency for Toxic Substances and Diseas e Registry. (1988) The nature and extent of lead poisoning in children in
the United States: a report to Congress. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service. Available from: NTIS, Springfield, VA; PB89-100184.
Ahern, M. D.; Morris, S. (1998) Accumulation of lead and its effects on Na balance in the freshwater crayfish

Cherax destructor . J. Exp. Zool. 281: 270-279.

Ainsworth, C. C.; Pilon, J. L.; Gassman, P. L.; Van Der Sluys, W. G. (1994) Cobalt, cadmium, and lead sorption to
hydrous iron-oxide: residence time effect. Soil Sci. Soc. Am. J. 58: 1615-1623.
Aka, H.; Darici, C. (2004) Carbon and nitrogen mineraliz ation of lead treated soils in the eastern Mediterranean region, Turkey. Soil Sediment Contam. 13: 255-265.

Al-Wabel, M. A.; Heil, D. M.; Westfa ll, D. G.; Barbarick, K. A. (2002) Solution chemistry influence on metal
mobility in biosolids-amended soils. J. Environ. Qual. 31: 1157-1165. Alam, M. K.; Maughan, O. E. (1995) Acute toxicity of heavy metals to common carp ( Cyprinus carpio ). J. Environ.

Sci. Health A 30: 1807-1816.
Albers, P. H.; Camardese, M. B. (1 993a) Effects of acidifi cation on metal accumulation by aquatic plants and

invertebrates. 1. Constructed wetlands. Environ. Toxicol. Chem. 12: 959-967.
Albers, P. H.; Camardese, M. B. (1993b) Effects of acidification on metal accumula tion by aquatic plants and
invertebrates. 2. Wetlands, ponds and small lakes. Environ. Toxicol. Chem. 12: 969-976. Allen, P. (1993) Effects of acute expo sure to cadmium (II) chloride and lead (II) chloride on the haematological
profile of Oreochromis aureus (Steindachner). Comp. Biochem. Physiol. C: Pharmacol. Toxicol.

Endocrinol. 105C: 213-217. Allen, P. (1994) Accumulation profiles of lead and the influence of cadmium and mercury in Oreochromis aureus
(Steindachner) during chronic exposure. Toxicol. Environ. Chem. 44: 101-112.

Allen-Gil, S.; Gubala, C. P.; Landers, D. H.; Lasorsa, B. K.; Crecelius, E. A.; Curtis, L. R. (1997) Heavy metal

accumulation in sediment and freshwater fish in U.S. Arctic lakes. Envi ron. Toxicol. Ch em. 16: 733-741.
Allinson, D. W.; Dzialo, C. (1981) The influence of lead, cadmium and nickel on the growth of ryegrass and oats.

Plant Soil 62: 81-89.
American Public Health Association. (1995) Standard methods for the examination of water and wastewater.
Method 6251B. Disinfection by-products: haloacetic acids and trichlorophenol. 19th ed. Washington, DC: American Public Health Association, pp. 6-67-6-76.
Amiard, J.-C.; Metayer, C.; Baud, J.-P.; Ribeyre, F. (1994) Influence de facteurs ecologiques et biologiques sur la
bioaccumulation d'elements metalliques chez de jeunes huitres ( Crassostrea gigas thunberg) au cours du pregrossissement en nourricerie (Influence of so me ecological and biological factors on metal
bioaccumulation in young oysters ( Crassostrea gigas Thunberg) during their spat rearing]. Water Res.

28: 219-231.

An, Y.-J.; Kim, Y.-M.; Kwon, T.-M.; Jeong, S.-W. (2004) Comb ined effect of copper, cadmium, and lead upon

Cucumis sativus growth and bioaccumulation. Sc i. Total Environ. 326: 85-93.
Andersen, M. K.; Raulund-Rasmussen, K.; Hansen, H. C. B.; Strobel, B. W. (2002) Distribution and fractionation of heavy metals in pairs of arable and afforested soils in Denmark. Eur. J. Soil Sci. 53: 491-502.
Anderson, M. B.; Preslan, J. E.; Jolibois, L.; Bollinger, J. E.; George, W. J. (1997) Bioaccumulation of lead nitrate
in red swamp crayfish ( Procambrus clarkii ). J. Hazard. Mat. 54: 15-29. Angelova, V.; Ivanov, K.; Ivanova, R. (2004) Effect of ch emical forms of lead, cadmium and zinc in polluted soils
on their uptake by tobacco. J. Plant Nutr. 27: 757-773.

# AX7-212 Angle, C. R.; McIntire, M. S.; Colucci , A. V. (1974) Lead in air, dustfa ll, soil, housedust, milk and water:

correlation with blood lead of urban and suburban school children. In: Hemphill, D. D., ed. Trace substances in environmental health - VIII: [proceedings of Univer sity of Missouri's 8th annual conference on trace

substances in environmental health]; June; Colu mbia, MO. Columbia, MO: University of Missouri;
pp. 23-29. Angle, C. L.; Marcus, A.; Cheng, I.-H.; McIntire, M. S. (1984) Omaha childhood bl ood lead and environmental
lead: a linear total exposure model. Environ. Res. 35: 160-170.
Antosiewicz, D. M (2005) Study of cal cium-dependent lead-tolerance on plants differing in their level of Ca-deficiency tolerance. Envi ron. Pollut. 134: 23-34.
Arai, T.; Maeda, M.; Yamakawa, H.; Kamatani, A.; Miy azaki, N. (2002) Growth e ffect on the uptake and

elimination of trace metals in the abalones Haliotis . Fish. Sci. 68: 1094-1098. Archer, D.; Emerson, S.; Reimers, C. (1989) Dissolution of calcite in deep-sea sediments: pH and O 2 

# microelectrode

results. Geochim. Cosmochim. Acta 53: 2831-2845. Aronson, A. L. (1971) Biologic effects of lead in fish. J. Wash. Acad. Sci. 61: 124-128.
Atchison, G. J.; Murphy, B. R.; Bishop , W. E.; McIntosh, A. W.; Mayes, R. A. (1977) Trace metal contamination of
bluegill ( Lepomis macrochirus ) from two Indiana lakes. Trans. Am. Fish Soc. 106: 637-640. Aualiitia, T. U.; Pickering, W. F. ( 1987) The specific sorption of trace amount s of Cu, Pb, and Cd by inorganic
particulates. Water Air Soil Pollut. 35: 171-185.
Austen, M. C.; McEvoy, A. J. (1997) The use of of fshore meiobenthic communities in laboratory microcosm experiments: response to heavy metal contamination. J. Exp. Mar. Biol. Ecol. 21: 247-261. Bååth, E. (1989) Effects of heavy metals in soil on microbial processes and populations (a review). Water Air Soil

Pollut. 47: 335-379. Bååth, E.; Arnebrant, K.; Nordgren, A. (1991) Microbial biomass and ATP in smelter-polluted forest humus. Bull.

Environ. Contam. Toxicol. 47: 278-282.
Baatrup, E. (1991) Structural and functional effects of heavy metals on the nervous system, including sense organs, of fish. Comp. Biochem. Physiol. C 100: 253-257.

Backes, C. A.; McLaren, R. G.; Rate, A. W.; Swift, R. S. (1995) Kinetics of cadmium and cobalt desorption from
iron and manganese oxides. Soil Sci. Soc. Am. J. 59: 778-785.
Bacon, J. R.; Bain, D. C. (1995) Characterization of environmental water samples using strontium and lead
stable-isotope compositions. Environ. Geochem. Health 17: 39-49.
Bacon, J. R.; Hewitt, I. J. (2005) Heavy metals deposite d from the atmosphere on upland Scottish soils: chemical and lead isotope studies of the association of metals with soil components. Geochim. Cosmochim.

Acta 69: 19-33. Bacon, J. R.; Berrow, M. L.; Shand, C. A. (1995) The use of isotopic composition in field studies of lead in upland
Scottish soils (U.K.). Chem. Geol. 124: 125-134.

Bacon, J. R.; Jones, K. C.; McGrath, S. P.; Johnston, A. E. (1996) Isotopic character of lead deposited from the atmosphere at a grassland site in the United Kingdo m since 1860. Environ. Sci. Technol. 30: 2511-2518.
Badawy, S. H.; Helal, M. I. D.; Chaudri, A. M.; Lawlor, K.; McGrath, S. P. (2002) So il solid-phase controls lead
activity in soil solution. J. Environ. Qual. 31: 162-167. Baier, R. W.; Healy, M. L. (1977) Pa rtitioning and transport of lead in Lake Washington. J. Environ. Qual.

6: 291-296. Balistrieri, L. S.; Murray, J. W.; Paul, B. (1994) The geochemical cyclying of trace elements in a biogenic

meromictic lake. Geochim. Cosmochim. Acta 58: 3993-4008.
Bargar, J. R.; Brown, G. E.; Parks, G. A. (1997a) Surface complexation of Pb(II) at oxide-water interfaces.
2. XAFS and bond-valence determination of mononuclear and polynuclear Pb(II) sorption products and surface functional groups on iron oxides. Geochim. Cosm ochim. Acta 61: 2639-2652.
Bargar, J. R.; Brown, G. E.; Parks, G. A. (1997b) Surface complexation of Pb(II) at oxide-wat er interfaces. I. XAFS
and bond-valence determination of mononuclear and polynuclear Pb(II) sorption products on aluminum

oxides. Geochim. Cosmochim. Acta 61: 2617-2637.
Bargar, J. R.; Brown, G. E.; Parks, G. A. (1998) Surface complexation of Pb(II) at oxide-water inte rfaces: III. XAFS
determination of Pb(II) and Pb(II)-chloro adsorption complexes on goethite and alumina. Geochim.

Cosmochim. Acta 62: 193-207.
Bargar, J. R.; Persson, P.; Brown, G. E. (1999) Outer-sphere adsorption of Pb(II) EDTA on goethite. Geochim.

Cosmochim. Acta 63: 2957-2969.
Barltrop, D.; Meek, F. (1979) Effect of particle size on lead absorption from the gut. Arch. Environ. Health

34: 280-285.

# AX7-213 Batonneau, Y.; Bremard, C.; Gengembre, L.; Laureyns, J.; Le Maguer, A.; Le Maguer, D.; Perdrix, E.; Sobanska, S.
(2004) Speciation of PM 10 

# sources of airborne nonferrous metals within the 3-km zone of lead/zinc smelters.

Environ. Sci. Technol. 38: 5281-5289.
Beaty, B. J.; Black, W. C.; Carlson, J. O.; Clements, W. H. DuTeau, N.; Harrahy, E.; Nucklos, J.; Olson, K. E.;
Rayms-Keller, A. (1998) Molecular and genetic ecotoxicologic approaches to aquatic environmental bioreporting. Environ. Health Perspect. 106(suppl. 6): 1395-1407.
Bechtel Jacobs Company (BJC). (1998) Empirical models for the uptake of inorganic chemicals from soil by plants.
Oak Ridge, TN: U.S. Department of Energy; BJC/OR-133.
Beckett, P. H. T. (1989) The use of ex tractants in studies on trace metals in soil, sewage sludges, and sludge-treated

soils. Adv. Soil Sci. 9: 143-176.
Beckett, P.; Davis, R. (1977) Upper critical levels of toxic elements in plants. New Phytol. 79: 95-106. Begley, I. S.; Sharp, B. L. (1997) Ch aracterization and correction of instrument al bias in inductively coupled plasma
quadrapole mass spectrometry for accurate measurement of lead isotope ratios. J. Anal. Atomic Spectrom.

12: 395-402. Behra, R. (1993a) In vitro effects of cadmium, zinc and lead on Calmondulin-dependent actions in Oncorhynchus
mykiss, Mytilus Sp ., and Chlamydomonas reinhardtii . Arch. Environ. Contam. Toxicol. 24: 21-27.
Behra, R. (1993b) Inte raction of cadmium, lead and zinc with calm odulin from rainbow trout, sea mussels, and a
green alga. Sci. Total Environ. (1 suppl.): 647-653.
Beijer, K.; Jernelov, A. (1984) Microbial methylation of lead . In: Grandjean, P., ed. Biolog ical effects of organolead compounds. Boca Raton, FL: CRC Press, Inc.; pp. 13-20.
Beiras, R.; Albentosa, M. (2003) Inhibition of embryo development of the commercial bivalves Ruditapes

decussatus and Mytilus galloprovincialis by trace metals; implications for the implementation of seawater quality criteria. Aquaculture 230: 205-213.
Bengstsson, G.; Gunnarsson, T.; Rundgren, S. (1986) Effects of metal pollution on the earthworm Dendrobaena

rubida (Sav.) in acidified soils. Water Air Soil Pollut. 28: 361-383. Benninger, L. K.; Lewis, D. M.; Turekian, K. K. (1975) The use of Pb-210 as a heavy metal tracer in the riverestuarine system. In: Church, T. M. , ed. Marine chemistry in the coas tal environment: a special symposium
sponsored by the Middle Atlantic Region at the 169th meeting of the American Chemical Society; April; Philadelphia, PA; pp. 202-210. (ACS Symposium Series 18).

Berbel, F.; Diaz-Cruz, J. M.; Arino, C.; Esteban, M.; Mas, F.; Garces, J. L.; Pu y, J. (2001) Voltammetric analysis of
heterogeneity in metal ion binding by humics. Environ. Sci. Technol. 35: 1097-1102. Bergkvist, B. (1986) Leaching of metals from a spruce forest soil as influenced by experimental acidification. Water

Air Soil Pollut. 31: 901-916. Berthelsen, B. O.; Steinnes, E. (1995) Accumulation patterns of heavy-metals in soil profiles as affected by forest
clear-cutting. Geoderma 66: 1-14.
Berthelsen, B. O.; Steinnes, E.; Solberg, W.; Jingsen, L. (1 995) Heavy metal concentrations in plants in relation to atmospheric heavy metal deposition. J. Environ. Qual. 24: 1018-1026.
Besser, J. M.; Brumbaugh, W. G.; Kemble, N. E.; May, T. W.; Ingersoll, C. G. (2004) Effects of sediment
characteristics on the toxicity of chromium(III) and chromium(VI) to the amphipod, Hyalella azteca

. Environ. Sci. Technol. 38: 6210-6216.
Besser, J. M.; Brumbaugh, W. G.; Brunson, E. L.; Ingersoll, C. G. (2005) Acute and chronic toxicity of lead in water
and diet to the amphipod Hyalella azteca . Environ. Toxicol. Chem. 24: 1807-1815. Beyer, W. N.; Pattee, O. H.; Sileo, L. ; Hoffman, D. J.; Mulhern, B. M. (1985) Metal contamination in wildlife living

near two zinc smelters. Environ. Pollut. Ser. A 38: 63-86.
Beyer, W. N.; Hensler, G.; Moore, J. (1987) Relation of p H and other soil variables to concentrations of Pb, Cu, Zn, Cd, and Se in earthworms. Pedobiologia 30: 167-172.
Beyer, W. N.; Audet, D. J.; Heinz, G. H.; Hoffman, D. J.; Day, D. (2000) Relation of waterfowl poisoning to
sediment lead concentrations in the Coeur d'Alene River basin. Ecotoxicology 9: 207-218.
Bianchini, A.; Bowles, K. C. (2002) Me tal sulfides in oxygenated aquatic systems: implications for the biotic ligand
model. Comp. Biochem. Physiol. Part C 133: 51-64.
Biggins, P. D. E.; Harrison, R. M. (1979) Atmospheric chemistry of automotive lead. Environ. Sci. Technol.

13: 558-565. Bilgrami, K. S.; Kumar, S. (1997) Effects of copper, lead and zinc on phytoplankton growth. Biol. Plant. (Biologica
Plantarum) 39: 315-317.
Bindler, R.; Brannvall, M.-L.; Renberg, I. (1999) Natural le ad concentrations in pristine boreal forest soils and past
pollution trends: a reference for critical load models. Environ. Sci. Technol. 33: 3362-3367.

# AX7-214 Black, M. C.; Ferrell, J. R.; Horning, R. C.; Martin, L. K., Jr. (1996) DNA strand brea kage in freshwater mussels
( Anodonta grandis ) exposed to lead in the laboratory and field. Environ. Toxicol. Chem. 15: 802-808. Blais, J. M. (1996) Using isotopic tracers in lake sediments to assess atmospheric transport of lead in Eastern

Canada. Water Air Soil Pollut. 92:329-342.
Blake, L.; Goulding, K. W. T. (2002) Effects of atmospheric deposition, soil pH and acidification on heavy metal contents in soils and vegetation of semi-natural ecosystems at Rothamsted Experimental Station, UK. Plant

Soil 240: 235-251.
Blasco, J.; Puppo, J. (1999) Effect of heavy metals (Cu, Cd and Pb) on aspartate and alanine aminotransferase in
Ruditapes philippinarum (Mollusca: Bivalvia). Comp. Biochem. Physiol. Part C: Pharmacol. Toxicol.

Endocrinol. 122C: 253-263.
Bloom, N. S.; Crecelius, E. A. (1987) Distribution of silv er, mercury, lead, copper, and cadmium in central Puget

Sound sediments. Mar. Chem. 21: 377-390.
Bodar, C. W. M.; Zee, V. D.; Voogt, P. A.; Wynne, H.; Za ndee, D. I. (1989) Toxicity of heavy metals to early life stages of Daphnia magna . Ecotoxicol. Environ. Saf. 17: 333-338.
Bodek, I.; Lyman, W. J.; Reehl, W. F.; Rosenblatt, D. H ., eds. (1988) Environmental inorganic chemistry properties,
processes, and estimation methods. Pergamon Press. pp.7.8.1-7.8-9.
Boisson, F.; Cotret, O.; Fowler, S. W. (2002) Transfer and distribution of lead in the asteroid Asterias rubens
following ingestion of contaminated food: a radiotracer study. Mar. Pollut. Bull. 44: 1003-1009.
Bongers, M. V.; Rusch, B.; Van Gestel, C. A. M. (2004) The effect of couterion and percolation on the toxicity of lead for the springtail Folsomia candida in soil. Environ. Toxicol. Chem. 23: 195-200.
Borgmann, U.; Kramar, O.; Loveridge, C. (1978) Rates of mortality, growth, and biomass production of Lymnaea palustris during chronic exposure to lead. J. Fish. Res. Board Can. 35: 1109-1115. Borgmann, U.; Norwood, W. P.; Clarke, C. (1993) Accumulation, regulaton and toxicity of copper, zinc, lead and
mercury in Hyalella azteca . Hydrobiologia 259: 79-89.
Borgmann, U.; Couillard, Y.; Doyle, P.; Dixon, D. G. (2 005) Toxicity of sixty-three metals and metalloids to
Hyalella azteca at two levels of water hardness. Environ. Toxicol. Chem. 24: 641-652.
Bormann, F. H.; Likens, G. E. (1967) Nutrient cycling. Science (Washington, DC) 155: 424-429.

Bormann, F. H.; Likens, G. E.; Fisher , D. W.; Pierce, R. S. (1968) Nutrient loss accelerat ed by clear-cutting of a forest ecosystem. Science (Washington, DC) 159: 882-884.
Bornschein, R. L.; Succop, P. A.; Krafft, K. M.; Clark, C. S.; Peace, B.; Hammond, P. B. (1987) Exterior surface
dust lead, interior house dust lead and childhood lead exposure in an urban environment. In: Hemphill, D.

D. ed. Trace substances in enviro nmental health-XX, proceedings of the University of Missouri's 20th
annual Conference, pp. 322-332; June 1986; Columbia, MO.

Botelho, C. M. S.; Boaventura, R. A. R.; Gonçalves, M. L. S. S.; Sigg, L. (1994) Interactions of lead(II) with natural

river water. Part II. Particulate matter. Sci. Total Environ. 151: 101-112.
Boyle, E. A.; Bergquist, B. A.; Kays er, R. A.; Mahowald, N. (2005) Iron, manganese, an d lead at Hawaii Ocean Time-series station ALOHA: temporal variability and an intermediate water hydrothermal plume. Geochim.

Cosmochim. Acta 69: 933-952.
Brännvall, M.-L.; Bindler, R.; Emteryd, O.; Renberg, I. (2001a) Vertical distribution of atmospheric pollution lead

in Swedish boreal forest soils. Water Air Soil Pollut. Focus 1: 357-370.
Brännvall, M.-L.; Kurkkio, H.; Bindler, R.; Emteryd, O.; Renberg, I. (2001b) The role of pollution versus natural
geological sources for lead enrichment in recent lake sediments and surface forest soils. Environ. Geol. 40:

1057-1065. Brar, R. S.; Sandhu, H. S.; Grewal, G. S. (1997a) Biochemical alterations induced by repeated oral toxicity of lead

in domestic fowl. Indian Vet. J. 74: 380-383.

Brar, R. S.; Sandhu, H. S.; Randhawa, S. S.; Grewal, G. S. (1997b) Effect of repeated oral toxicity of lead on
activities of some plasma enzymes in domestic fowls. Indian J. Anim. Sci. 67: 878-879.
Brook, E. J.; Moore, J. N. (1988) Particle-size and chem ical control of As, Cd, Cu, Fe, Mn, Ni, Pb, and Zn in bed
sediment from the Clark Fork River, Montana (U.S.A.). Sci. Total Environ. 76: 247-266.
Brown, S. B.; Evans, R. E.; Thompson, B. E.; Hara, T. J. (1982) Chemoreception and aquatic pollutants. In: Hara, T.
J., ed. Chemoreception in fishes. New York, NY: Else vier Scientific Publis hing Co.; pp. 363-393. [Developments in aquaculture and fisheries science, v. 8].
Brown, S. L.; Chaney, R. ; Berti, B. (1999) Field test of amendments to reduce the in situ availability of soil lead. In:

Wenzel, W. W.; Adriano, D. C.; Doner, H. E.; Ke ller, C.; Lepp, N. W.; Mench, M. W.; Naidu, R.;
Pierzynski, G. M., eds. Abstracts of the 5th international conference on biogeochemistry of trace elements;
July; Vienna, Austria. Vienna, Austria: Inte rnational Society for Tr ace Element Research.

# AX7-215 Brown, S. L.; Chaney, R. L.; Hallfrisch, J. G.; Xue, Q. (2003a) Effect s of biosolids processing on the bioavailability
of lead in urban soils. J. Environ. Qual. 32: 100-108. Brown, S. L.; Henry, C. L.; Compton, H.; Chaney, R.; DeVolder, P. S. (2003b) Using municipal biosolids in
combination with other residuals to restore metal-contaminated mining areas. Plant Soil 249: 203-215.
Brunekreef, B.; Noy, D.; Bier steker, K.; Boleij, J. (1983) Blood lead levels in Dutch city children and their relationship to lead in the environment. J. Air Pollut. Control Assoc. 33: 872-876.
Burger, J.; Carruth-Hinchey, C.; Ondroff, J.; McMahon, M.; Gibbons, J. W.; Gochfeld, M. (1998) Effects of lead on
behavior, growth, and survival of hatchling slider turtle s. J. Toxicol. Environ. Health Part A. 55: 495-502. Camp, Dresser, and McKee (CDM); Drexler, J.; Roy F. We ston Group, Inc.; R. J. Lee Group, Inc. (1994) Metal
speciation report Leadville, Colorado. California Gulc h CERCLA site. (draft). De nver, CO: Prepared for
Resurrection Mining Company, U.S. Environmental Protection Agency, and ASARCO. Canli, M.; Furness, R. W. (1993) Toxicity of heavy metals dissolved in sea water and influences of sex and size on

metal accumulation and tissue distri bution in the Norway lobster Nephrops norvegicus . Mar. Environ. Res.

36: 217-236. Cannon, R. S.; Pierce, A. P.; Delevaux, M. H. (1963) Lead isotope variation with growth zoning in a single crystal.
Science (Washington, DC) 142: 574-576. Cao, X.; Ma, Q. Y.; Chen, M.; Singh, S. P.; Harris, W. G. (2002) Impact s of phosphate amendments on lead
biogeochemistry at a contaminated site. Environ. Sci. Technol. 36: 5296-5304.
Capelo, S.; Vilhena, M. F.; Gonçalves, M. L. S.S.; Sampayo, M. A. (1993) Effect of lead on the uptake of nutrients by unicellular algae. Water Res. 27: 1563-1568.
Capodaglio, G.; Coale, K. H. ; Coale, K. W. (1990) Lead speciation in su rface waters of the eastern North Pacific.

Mar. Chem. 29: 221-233.
Carline, R. F.; Jobsis, G. J. (1993) Assessment of aquatic animal communities in the vicinity of the Palmerton,
Pennsylvania, zinc smelters. Environ. Toxicol. Chem. 12: 1661-1670.
Carlson, A. R.; Nelson, H.; Hammermeister, D. (1986) Development and validation of site-specific water quality criteria for copper. Environ. Toxicol. Chem. 5: 997-1012.
Carter, L. F.; Porter, S. D. (1 997) Trace-element accumulation by Hygrohypnum ochraceum in the upper Rio

Grande basin, Colorado and New Mexico, USA. Environ. Toxicol. Chem. 16: 2521-2528.
Casas, A. M.; Crecelius, E. A. (1994) Relationship between acid volatile sulfide and the toxicity of zinc, lead and
copper in marine sediments. Environ. Toxicol. Chem. 13: 529-536.
Case, J. M.; Reif, C. B.; Timko, A. (1989) Lead in the bottom sediments of Lake Nuangola and fourteen other bodies of water in Luzerne County, Pennsylvania. J. Pennsylvania Acad. Sci. 63: 67-72.

Castro, L.; Carmo, C.; Peres, I.; Pihan, J. C. (1996) The clam, Ruditapes decussatus L., as a pollution bioindicator: zinc and lead accumulation and depuration. Écologie 27: 263-268.

Cestari, M. M.; Lemos, P. M. M.; Ribe iro, C.; Costa, J. R.; Pe lletier, E.; Ferraro, M.; Mant ovani, M. S.; Fenocchio,
A. S. (2004) Genetic damage induced by trophic doses of lead in the neotropical fish Hoplias malabaricus (Characiformes, Erythrinidae) as revealed by the co met assay and chromosomal aberrations. Genet. Mol.

Biol. 27: 270-274.
Chadwick, J. W.; Canton, S. P.; Dent, R. L. (1986) Rec overy of benthic invertebrate communities in Silver Bow Creek, Montana, following improved metal mine wastewater treatment. Water Air Soil Pollut. 28: 427-438.
Chander, K.; Dyckmans, J.; Ho eper, H.; Joergensen, R. G.; Raubuch, M. (2001) Long-term effects on soil microbial
properties of heavy metals from industrial exhaus t deposition. J. Plant Nutr. Sci. 164: 657-663. Chaney, R. L.; Ryan, J. A. (1994) Risk based standards for arsenic, lead and cadmium in urban soils. Frankfurt,
Germany: DECHEMA. (Dechema-Fachgespräche Umweltschutz Series).

Charlatchka, R.; Cambier, P.; Bourgeois, S. (1997) Mobilization of trace metals in contaminated soils under

anaerobic conditions. In: Prost, R., ed. Contaminated soils, proceedings of the 3rd international conference
on the biogeochemistry of trace elements; May, 1995; Paris, France.
Chen, C. -C.; Coleman, M. L.; Katz, L. E. (2006) Bridging the gap between macroscopic and spectroscopic studies of metal ion sorption at the oxide/wate r interface: Sr(II), Co(II) , and Pb(II) sorption to quartz. Environ. Sci.

Technol. 40: 142-148.
Chillrud, S. N.; Hemming, S.; Shuster, E. L.; Simpson, H. J. ; Bopp, R. F.; Ross, J. M.; Pederson, D. C.; Chaky, D. A.; Tolley, L.-R.; Estabrooks, F. (2003) Stable lead isotopes, contaminant metals and radionuclides in upper
Hudson River sediment cores: implications for improved time stratigraphy and transport processes. Chem.

Geol. 199: 53-70.

Chow, T. J.; Bruland, K. W.; Bertine, K.; Soutar, A. ; Koide, M.; Goldberg, E. D. (1973) Lead pollution: records in
Southern California coastal sediments. Science (Washington, DC, U.S.) 181: 551-552.

# AX7-216 Clements, W. H. (1994) Benthic invertebrate community responses to heavy metals in the Upper Arkansas River

Basin, Colorado. J. N. Am. Benthol. Soc. 13: 30-44. Clevenger, T. E.; Saiwan, C.; Koirtyohan n, S. R. (1991) Lead speciation of particles on air filters collected in the
vicinity of a lead smelter. Environ. Sci. Technol. 25: 1128-1133.
Coello, W. F.; Khan, M. A. Q. (1996) Protection against heavy metal toxicity by mucus and scales in fish. Arch.

Environ. Contam. Toxicol. 30: 319-326.

Cotrufo, M. F.; De Santo, A. V.; Alfani, A.; Bartoli, G. ; De Cristofaro, A. (1995) Effects of urban heavy metal
pollution on organic matter decomposition in Quercus ilex L. woods. Environ. Pollut. 89: 81-87. Cotter-Howells, J.; Caporn, S. (1996) Remediation of contaminated land by formation of heavy metal phosphates.
Appl. Geochem. 11: 335-342.
Covington, W. W. (1981) Changes in forest floor organic matter and nutrient content following clear cutting in northern hardwoods. Ecology 62: 41-48.

Cowherd, C., Jr.; Axtell, K., Jr.; Guen ther, C. M.; Jutze, G. A. (1974) Development of emission factors for fugitive dust sources. Research Triangle Park, NC: U.S. Envir onmental Protection Agency, Office of Air Quality
Planning and Standards; EPA report no. EPA-450/3-74-037. Available from: NTIS, Springfield, VA; PB238262. Dalenberg, J. W.; Van Driel, W. (1990) Contribution of atmospheric deposition to heavy-metal concentrations in
field crops. Neth. J. Agric. Sci. 38: 369-379.
Dave, G. (1992a) Sediment toxicity and heavy metals in eleven lime reference lakes of Sweden. Water Air Soil

Pollut. 63: 187-200. Dave, G. (1992b) Sediment toxicity in lakes along the river Kolbäcksån, central Sweden Hydrobiologia

236: 419-433. Davies, P. H.; Everhart, W. H. (1973) Effects of chemical variations in aquatic environments: volume 3 lead toxicity
to rainbow trout and testing application factor conc ept. Washington, DC: U.S. Environmental Protection
Agency; report no. EPA-R3-73-011C. Available from: NTIS, Springfield, VA; PB-221345. Davies, P. H.; Goettl, J. P.; Sinley, J. R.; Smith, N. F. (1976) Acute and chronic toxicity of lead to rainbow trout
Salmo gairdneri, in hard and soft water. Water Res. 10: 199-206.
Davies, N. A.; Hodson, M. E.; Black, S. (2002) Changes in t oxicity and bioavailability of lead in contaminated soils

to the earthworm Eisenia Fetida (Savigny 1826) after bone meal amendments to the soil. Environ. Toxicol.

Chem. 21: 2685-2691.
Davies, N. A.; Hodson, M. E.; Black, S. (2003) The in fluence of time on lead toxicity and bioaccumulation determined by the OECD earthworm toxicity test. Environ. Pollut. 121: 55-61.
Davis, A.; Galloway J. N. (1993) Distribution of Pb between sediments and pore water in Woods Lake, Adirondack State Park, New York, U.S.A. Appl. Geochem. 8:51-65.
Davis, A.; Drexler, J. W.; Ruby, M. V.; Nicholson, A. (1 993) Micromineralogy of mine wastes in relation to lead
bioavailability, Butte, Montana. Environ. Sci. Technol. 27: 1415-1425. Davis, A.; Sellstone, C.; Clough, S.; Barrick, R.; Yare, B. (1996) Bioaccumulation of arsenic, chromium and lead in
fish: constraints imposed by sediment geochemistry. Appl. Geochem. 11: 409-423.
Davison, W.; Zhang, H. (1994) In situ speciation measurements of trace components in natural waters using thinfilm gels. Nature 367: 546-548.
Davison, W.; Grime, G. W.; Morgan, J. A. W.; Clarke, K. (1991) Distribution of dissolved iron in sediment pore
waters at submillimetre resolution. Nature (London) 352: 323-325. Davison, W.; Zhang, H.; Grime, G. W. (1994) Performance characteristics of gel probes used for measuring pore

waters. Environ. Sci. Technol. 28: 1623-1632.
De Jonghe, W. R. A.; Adams, F. C. (1986) Biogeochemical cycling of organic lead compounds. In: Nriagu, J. O.; Davidson, C. I., eds. Toxic metals in the atmosphe re. New York, NY: John Wiley & Sons; pp. 561-594.
(Advances in environmental scie nce and technology: v. 17).
De Schamphelaere, K. A. C.; Janssen, C. R. (2004) Development and field validation of a biotic ligand model predicting chronic copper toxicity to Daphnia magna . Environ. Toxicol. Chem. 23: 1365-1375.

DeVolder, P. S.; Brown, S. L.; Hester berg, D.; Pandya, K. (2003) Metal bioavailability and speciation in a wetland
tailings repository amended with biosolids compost, wood ash, and sulfate. J. Environ. Qual. 32: 851-864. Deacon, J. R.; Spahr, N. E. ; Mize, S. V.; Boulger, R. W. (2001) Using water, bryophytes, and macroinvertebrates to
assess trace element concentrations in the Upper Colorado River basin. Hydrobiologia 455: 29-39. Dearth, R. K.; Hiney, J. K.; Srivastava , V.; Les Dees, W.; Bratton, G. R. (2004) Low level lead (Pb) exposure during
gestation and lactation: assessment of effects on pubertal development in Fisher 344 and Sprague-Dawley

female rats. Life Sci. 74: 1139-1148.

# AX7-217 Deng, H.; Ye, Z. H.; Wong, M. H. (2004) Accumulation of lead, zinc, copper and cadmium by 12 wetland species
thriving in metal-contaminated sites in China. Environ. Pollut. 132: 29-40. Di Toro, D. M.; Mahoney, J. D.; Hansen, D. J.; Scott, K. J.; Carlson, A. R. (1992) Acid volatile sulfide predicts the
acute toxicity of cadmium and nickel in sediments. Environ. Sci. Technol. 26: 96-101.
Di Toro, D. M.; Allen, H. E.; Bergman, H. L.; Meyer, J. S. ; Paquin, P. R.; Santore, R. C. (2001) Biotic ligand model of the acute toxicity of metals. 1. Technical basis. Environ. Toxicol. Chem. 20: 2383-2396.
Dixon, R. K. (1988) Response of ectomycorrhizal Quercus rubra to soil cadmium, nickel and lead. Soil Biol.

Biochem. 20: 555-559. Doe, B.; Rohrbough, R. (1977) Lead isotope data bank: 3,458 samples and analyses cited. U.S. Geological Survey
open-file report 79-661.
Doe, B. R.; Stacey, J. S. (1974) The application of lead isotopes to the problems of ore genesis and ore prospect

evaluation: a review. Econ. Geol. 69: 757-776.
Doe, B. R.; Tilling, R. I.; Hedge, C. E.; Klepper, M. R. (1968) Lead and strontium isotope studies of the Boulder

batholith, southwestern Montana. Econ. Geol. 63: 884-906.
Doelman, P.; Haanstra, L. (1986) Shor t- and long-term effects of heavy metals on urease activity in soils. Biol.

Fertil. Soils 2: 213-218. Dolske, D. A.; Sievering, H. (1979) Trace element lo ading of southern Lake Michigan by dry deposition of
atmospheric aerosol. Water Air Soil Pollut. 12: 485-502.
Dörr, H. (1995) Application of 210Pb in Soils. J. Paleolimnol. 13: 157-168. Dörr, H.; Münnich, K. O. (1989) Downward movement of soil organic-matter and its influence on trace-element
transport (210Pb, 137Cs) in the soil. Radiocarbon 31: 655-663.
Dörr, H.; Münnich, K. O. (1991) Lead and cesium tran sport in European forest soils. Water Air Soil Pollut.

57/58: 809-818.
Douben, P. E. T. (1989) Lead and cadmium in stone loach ( Noemacheilus barbatulus L.) from three rivers in
Derbyshire. Ecotoxicol. Environ. Saf. 18: 35-58. Douglas-Stroebel, E. K.; Brew er, G. L.; Hoffman, D. J. (2005) Effects of lead-contaminated sediment and nutrition
on mallard duckling behavior and growth. J. Toxicol. Environ. Health Part A 68: 113-128.
Drava, G.; Capelli, R.; Minganti, V.; De Pellegrini, R.; Relini, L.; Ivaldi, M. (2 004) Trace elements in the muscle of red shrimp Aristeus antennatus (Risso, 1816) (Crustacea, Deca poda) from Ligurian sea (NW
Mediterranean): variations related to the reproductive cycle. Sci. Total Environ. 321: 87-92.
Drexler, J. W. (1997) Valida tion of an in vitro method: a tandem approach to estimating the bioavailability of lead and arsenic in humans. quantifying the real toxicity of common soil contaminants, IBC conference on
bioavailability; December; Scottsdale, AZ. Drexler, J. W. (2004) A study on the speciation and bioac cessability of anomalous lead co ncentrations in soils from
Herculaneum community. Herculaneum, MO: U.S. Environmental Protection Agency, Region 7.
Drexler, J. W.; Mushak, P. (1995) Health risks from ex tractive industry wastes: characterization of heavy metal contaminants and quantification of their bioavailability and bioaccessability. Presented at: The third

international conference on th e biogeochemistry of trace elem ents; May; Paris, France.
Driscoll, C. T.; Fuller, R. D.; Simone, D. M. (1988) Longitudinal variations in trace metal concentrations in a northern forested ecosystem. J. Environ. Qual. 17: 101-107.

Driscoll, C. T.; Likens, G. E.; Church , M. R. (1998) Recovery of surface wa ters in the northeastern U.S. from
decreases in atmospheric deposition of sulfur. Water Air Soil Pollut. 105: 319-329.
Duan, Y.; Guttman, S.; Oris, J.; Bailer, J. (20 00) Genotype and toxicity relationships among Hyalella azteca : I. acute exposure to metals or low pH. Environ. Toxicol. Chem. 19: 1414-1421.
Dupont, L.; Guillon, E.; Bouanda, J.; Dumonceau, J.; Ap lincourt, M. (2002) EXAF S and XANES studies of retention of copper and lead by a lignocellulosic biom aterial. Environ. Sci. Technol. 36: 5062-5066.
Durand, P.; Neal, C.; Jeffery, H. A.; Ryland, G. P.; Neal , M. (1994) Major, minor and trace-element budgets in the
Plynlimon afforested catchments (Wales): general trends, and effects of felling and climate variations. J. Hydrol. 157: 139-156.
Egli, M.; Fitze, P.; Oswald, M. (1999) Changes in heavy me tal contents in an acidic forest soil affected by depletion
of soil organic matter within the time span 1969-93. Environ. Pollut. 105: 367-379.
Eisler, R. (1988) Lead hazards to fish, wildlife, and in vertebrates: a synoptic review. Washington, DC: U.S.
Department of the Interior, Fish and Wildlife Service; biological report 85(1.14); contaminant hazard reviews report no. 14.
Eisler, R. (2000) Handbook of chemical risk assessment: hea lth hazards to humans, plants, and animals. Volume 1:

metals. Boca Raton, FL: Lewis Publishers.

# AX7-218 Ekenler, M.; Tabatabai, M. (2002) Effects of trace metals on β -glucosaminidase activity in soils. Soil Biol.

Biochem. 34: 1829-1832. Elzinga E. J.; Sparks D. L. (2002) X-ray absorption spectroscopy study of the effects of pH and ionic strength on
Pb(II) sorption to amorphous silica. Environ. Sci. Technol. 36: 4352-4357.
Emmanuel, S.; Erel, Y. (2002) Implications from concentra tions and isotopic data for Pb partitioning processes in

soils. Geochim. Cosmochim. Acta 66: 2517-2527.

Encinar, J. R.; García Alonso, J. I.; Sanz-Medel, A. ; Main, S.; Turner, P. J. (2001a) A comparison between
quadrupole, double focusing and multicollector ICP-MS: Part I. Evaluation of total combined uncertainty for lead isotope ratio measurements. J. Anal. At. Spectrom. 16: 315-321.

Encinar, J. R.; García Alonso, J. I.; Sanz-Medel, A. ; Main, S.; Turner, P. J. (2001b) A comparison between
quadrupole, double focusing and multicollector ICP-MS: Pa rt II. Evaluation of total combined uncertainty in the determination of lead in biological matrices by isotope dilution. J. Anal. At. Spectrom. 16: 322-326.
Enserink, E. L.; Maas-Diepeveen, J. L.; Van Leeuwen, C. J. (1991) Combined effects of metals; an ecotoxicological

evaluation. Water Res. 25: 679-687.
Erel, Y.; Patterson, C. C. (1994) Leakage of industrial lead into the hydrocycle. Geochim. Cosmochim. Acta

58: 3289-3296. Erel, Y.; Morgan, J. J.; Patterson, C. C. (1991) Natural levels of lead and cadmium in a remote mountain stream.

Geochim. Cosmochim. Acta 55: 707-719.
Erel, Y.; Veron, A.; Halicz, L. (1997) Tracing the transport of anthropogenic lead in the atmosphere and in soils using isotopic ratios. Geochim. Cosmochim. Acta 61: 4495-4505.

Erel, Y.; Emmanuel, S.; Teutsch, N.; Halicz, L.; Veron, A. (2001) Partitioning of anthropogenic and natural lead in
soils. Abst. Papers Am. Chem. Soc. 221: U467.

Erten-Unal, M.; Wixson, B. G.; Gale, N. ; Pitt, J. L. (1998) Evaluation of toxi city, bioavailability and speciation of
lead, zinc, and cadmium in mine/mill wastewaters. Chem. Spec. Bioavail. 10: 37-46.
Evans, G. C.; Norton, S. A.; Fernandez, I. J.; Kahl, J. S.; Hanson, D. (2005) Changes in concentrations of major

elements and trace metals in northeas tern U.S.-Canadian sub-alpine fore st floors. Water Air Soil Pollut.

163: 245-267 Farag, A. M.; Boese, C. J.; Woodward, D. F.; Bergman, H. L. (1994) Physiological changes and tissue metal accumulation in rainbow trout expose d to foodborne and waterborne me tals. Environ. Toxicol. Chem.

13: 2021-2029. Farfel, M. R.; Orlova, A. O.; Chaney, R. L.; Lees, P. S. J.; Rohde, C.; As hley, P. J. (2005) Biosolids compost amendment for reducing soil lead hazar ds: a pilot study of Orgro® ame ndment and grass seeding in urban
yards. Sci. Total Environ. 340: 81-95. Fargašová, A. (1993) Effect of five toxic metals on the alga Scenedesmus quadricauda . Biologia (Bratislava)

48: 301-304. Farkas, A.; Salánki, J.; Specziár, A. (2 003) Age- and size-specific patterns of heavy metals in the organs of

freshwater fish Abramis brama L. populating a low-contaminated site. Water Res. 37: 959-964.

Farmer, J. G.; Eades, L. J.; MacKenzie, A. B.; Kirika, A.; Bailey-Watts, T. E. (1996) Stable lead isotope record of
lead pollution in Loch Lomond sediments since 1630 A.D. Environ. Sci. Technol. 30: 3080-3083.

Farmer, J. G.; MacKenzie, A. B. ; Sugden, C. L.; Edgar, P. J.; Eades, L. J. (1997) A comparison of the historical lead
pollution records in peat and freshwater lake sediments from central Scotland. Water Air Soil Pollut.

100: 253-270. Faure, G. (1977) Principles of isotope geology. New York, NY: John Wiley & Sons.
Federer, C. A. (1984) Organic matter and nitrogen content of the forest floor in even-aged northern hardwoods. Can.

J. For. Res. 14: 763-767. Fendorf, S. E.; Sparks, D. L.; Lamble, G. M.; Kelley, M. J. (1994) Applications of x-ray absorption fine structure
spectroscopy to soils. Soil Sci. Soc. Am. J. 58: 1583-1595.
Fernandez-Leborans, G.; Novillo, A. (1 992) Hazard evaluation of lead effects using marine protozoan communities. Aquat. Sci. 54: 128-140.
Fernandez-Leborans, G.; Novillo, A. (1994) Effects of pe riodic addition of lead on a marine protistan community.
Aquat. Sci. 56: 191-205. Fernandez-Leborans, G.; Antonio-García, M. T. (1988) Effects of lead and cadmium in a community of protozoans.

Acta Protozool. 27: 141-159. Fernando, Q. (1995) Metal speciation in environmental and biological systems. Environ. Health Perspect. Suppl.
103(1): 13-16.

# AX7-219 Finney, D. J. (1947) The toxic action of mixtures of poi sons. In: Probit analysis: a st atistical treatment of the
sigmoid response curve. Cambridge, UK: Cambridge University Press; pp. 122-159. Fitzhugh, R. D.; Driscoll, C. T.; Groffman , P. M.; Tierney, G. L.; Fahey, T. J.; Hardy, J. P. (2001) Effects of soil
freezing disturbance on so il solution nitrog en, phosphorus, and carbon chemistry in a northern hardwood
ecosystem. Biogeochemistry 56: 215-238. Flegal, A. R; Rosman, K. J. R.; Stephenson, M. D. (198 7) Isotope systematics of co ntaminant leads in Monterey
Bay. Environ. Sci. Technol. 21: 1075-1079.
Flegal, A. R.; Duda, T. F.; Niemeyer, S. (1989a) High gradients of lead isotopic composition in north-east Pacific upwelling filaments. Nature 339: 458-460.
Flegal, A. R.; Nriagu, J. O.; Niemeyer, S.; Coale, K. H. (1989b) Isotopic tracers of lead c ontamination in the Great
Lakes. Nature (London) 339: 455-458. Florence, T. M. (1977) Trace metal species in fresh waters. Water Res. 25: 681-687.
Ford, R. G.; Scheinost, A. C.; Scheckel, K. G.; Sparks, D. L. (1999) The link between clay mineral weathering and the stabilization of Ni surface precipitates. Environ. Sci. Technol. 33: 3140-3144.
Förstner, U. (1987) Sediment-associated contaminants—an overview of scientific bases for developing remedial
options. Hydrobiologia 149: 221-246.
Francek, M. A. (1992) Soil lead levels in a small town environment: a case study fr om Mt. Pleasant, Michigan.

Environ. Pollut. 76: 251-257.
Francek, M. A. (1997) Soil lead levels in orchards and roadsides of Mission Peninsula, Michigan. Water Air Soil

Pollut. 94: 373-384.
Franson, J. C. (1996) Interpretation of tissue lead residues in birds other than waterfowl. In: Beyer, W. N.;

Heinz, G. H.; Redmon-Norwood, A. W., eds. Environm ental contaminants in wildlife. Interpreting tissue concentrations. Boca Raton, FL: CRC Press, pp. 265-279. [SETAC special publication series].
Friedland, A. J.; Johnson, A. H. (1985) Lead distribution and fluxes in a high-elevation forest in northern Vermont.
J. Environ. Qual. 14: 332-336.

Friedland, A. J.; Johnson, A. H.; Si ccama, T. G. (1984) Trace metal conten t of the forest floor in the Green
mountains of Vermont: spatial and temporal patterns. Water Air Soil Pollut. 21: 161-170.
Friedland, A. J.; Craig, B. W.; Miller, E. K.; Herrick, G. T.; Siccama, T. G.; Johnson, A. H. (199 2) Decreasing lead

levels in the forest floor of the northeastern USA. Ambio 21: 400-403.

Fritze, H.; Niini, S.; Mikkola, K.; Mäki nen, A. (1989) Soil microbial effects of Cu-Ni smelter in southwestern

Finland. Biol. Fert. Soils 8: 87-94. Fry, B.; Sherr, E. B. (1984) δ 13C measurements as indicators of carbon flow in marine and freshwater ecosystems.

Contrib. Mar. Sci. 27: 13-47.

Fu, M. H.; Tabatabai, M. A. (1989) Nitrate reductase in soils: effect s of trace elements. Soil Biol. Biochem.

21: 943-946.

Fuller, R. D.; Simone, D. M.; Driscoll, C. T. (1988) Forest clear cutting effects on trace meta l concentrations: spatial patterns in soil solutions and streams. Water Air Soil Pollut. 40: 185-195.
Galbraith, H.; LeJeune, K.; Lipton, J. (1995) Metal and arsenic impacts to soils, vegetation communities and wildlife
habitat in southwest Montana uplands contaminated by smelter emissions: I. Field evaluation. Environ.

Toxicol. Chem. 14: 1895-1903.
Gallon, C.; Tessier, A.; Gobeil, C. (2006) Historical perspe ctive of industrial lead emi ssions to the atmosphere from

a Canadian smelter. Environ. Sci. Technol. 40: 741-747. Galloway, J. N.; Thornton, J. D.; Norton, S. A.; Volchok, H. L.; McLean, R. A. N. (1982) Trace metals in
atmospheric deposition: a review and assessment. Atmos. Environ. 16: 1677-1700.

Gamble, D. S.; Schnitzer, M.; Kerndorff, H.; Langford, C. H. (1983) Multiple metal ion exchange equilibria with

humic-acid. Geochim. Cosmochim. Acta 47: 1311-1323.

Gao, Y.; Kan, A. T.; Tomson, M. B. (2003) Critical evaluation of desorption phenomena of heavy metals from

natural sediments. Environ. Sci. Technol. 37: 5566-5573. Garcia, T. A.; Corredor, L. (2004) Biochemical changes in the kidneys after perinatal intoxication with lead and/or
cadmium and their antagonistic effects when coadmi nistered. Ecotoxicol. Environ. Saf. 57: 184-189.

Gaur, J. P.; Noraho, N.; Ch auhan, Y. S. (1994) Relationship between heavy metal accumulation and toxicity in
Spirodela polyrhiza (L.) Schleid. and Azolla pinnata R. Br. Aquat. Bot. 49: 183-192. Gavrilenko, Y. Y.; Zolotukhina, Y. Y. (1989) Accumulation and interaction of copper, zinc, manganese, cadmium, nickel and lead ions adsorbed by aquatic macrophytes. Hydrobiol. J. 25: 54-61.
Gerhardt, A. (1994) Short term toxicity of iron (Fe) and lead (Pb) to the mayfly Leptophlebia marginata (L. )
(Insecta) in relation to freshwater aci dification. Hydrobiologia 284: 157-168.

# AX7-220 Getz, L. L.; Haney, A. W.; Larimore, R. W.; McNurney, J. W.; Lelend, H. V.; Price, P. W.; Rolfe, G. L.; Wortman,

R. L.; Hudson, J. L.; Solomon, R. L.; Reinbold, K. A. (1977) Transport and distribution in a watershed ecosystem. In: Boggess, W. R., ed. Lead in the environment. Washington, DC: National Science
Foundation; pp. 105-133; NSF report no. NSF/RA-770214.
Ghazi, A. M.; Millette, J. R. (2004) Environmental forensic application of lead isotope ratio determination: a case study using laser ablation sector ICP-MS. Environ. Forensics 5: 97-108.
Giamberini, L.; Pihan, J.-C. (1996) The pericardial glands of the zebra mussel: ultrastructure and implication in lead
detoxication process. Biol. Cell (Paris) 86: 59-65.
Gill, T. S.; Tewari, H.; Pande, J. (1991 ) Effects of water-borne copper and lead on the peripheral blood in the rosy

barb, Barbus (Puntius) conchonius Hamilton. Bull. Environ. Contam. Toxicol. 46: 606-612.

Gintenreiter, S.; Ortel, J.; Nopp, H. J. (1993) Bioaccumula tion of cadmium, lead, copper, and zinc in successive developmental stages of Lymantria dispar L. ( Lymantriidae, Lepid )—a life cycle study. Arch. Environ.

Contam. Toxicol. 25: 55-61. Giusti, L.; Yang, Y. L.; Hewitt, C. N. ; Hamilton-Taylor, J.; Davison W. (19 93) The solubility and partitioning of
atmospherically derived trace metals in artificial and natural waters: a review. Atmos. Environ. Part A

27: 1567-1578. Glover, L. J., II; Eick, M. J.; Brady, P. V. (2002) Desorption kinetics of cadmium2+ and lead2+ from goethite:
influence of time and organic acids. Soil Sci. Soc. Am. J. 66: 797-804.
Gobeil, C.; Johnson, W. K.; Macdonald, R. W.; Wong, C. S. (1995) Sources and burden of lead in St. Lawrence estuary sediments: isotopic evidence. Environ. Sci. Technol. 29: 193-201.
Gobeil, C.; Bondeau, B.; Beaudin, L. (2005) Contribution of municipal effluents to metal fluxes in the St. Lawrence

River. Environ. Sci. Technol. 39: 456-464. Goldstein, J. I.; Newbury, D. E.; Echlin, P.; Joy, D. C.; Roming, A. D., Jr.; Lyman, C. E.; Fiori, C.; Lifshin, E.
(1992) Scanning electron microscopy and x-ray microanalysis: a text for biologists, materials scientists, and
geologists. 2nd. Ed. New York, NY: Plenum Press. Gopal, V.; Parvathy, S.; Balasubramanian, P. R. (1997) Effect of heavy metals on the blood protein biochemistry of

the fish Cyprinus carpio and its use as a bio-indicator of pollution stress. Environ. Monit. Assess.

48: 117-124. Gosz, J. R.; Likens, G. E.; Bormann, F. H. (1976) Organic matter and nutrient dynamics of the forest and forest floor
in the Hubbard Brook forest. Oecologica 22: 305-320.
Graney, J. R.; Halliday, A. N.; Keeler, G. J.; Nriagu, J. O.; Robbins, J. A.; No rton, S. A. (1995) Isotopic record of lead pollution in lake sediments from the northeastern United States. Geochim. Cosmochim. Acta

59: 1715-1728. Graney, J. R.; Keeler, G. J.; Norton, S. A.; Church, S. E.; Halliday, A. N. (1996) Historical record of mining at
Leadville, CO preserved in sediment from Emeral d Lake in Rocky Mountain National Park. In:
Geological Society of America abstracts with programs, v. 28, no. 7. Boulder, CO: Geological Society of America; pp. 156.
Grelle, C.; Fabre, M.-C.; Leprêtre, A.; Descamps, A. (2000) Myriapod and isopod communities in soils
contaminated by heavy metals in northern France. Eur. J. Soil Sci. 51: 425-433.

Griscom, S. B.; Fisher, N. S.; Aller, R. C.; Lee, B. G. (2002) Effects of gut chemistry in marine bivalves on the
assimilation of metals from ingested sediment particles. J. Mar. Res. 60: 101-120.
Groffman, P. M.; Driscoll, C. T.; Fahey, T. J.; Hardy, J. P.; Fitzhugh, R. D.; Tierney, G. L. (2001) Effects of mild winter freezing on soil nitrogen and carbon dynamics in a northern hardwood fo rest. Biogeochemistry

56: 191-213. Gundersen, J. K.; Jorgensen, E. L.; Larsen, E.; Jannasch, H. W. (1992) Mats of giant sulfur bacteria on deep-sea sediments due to fluctuating hydrothermal flow. Nature 360: 454-456.
Gupta, M.; Chandra, P. (1994) Lead accumulation and toxicity in Vallisneria spiralis (L.) and Hydrilla verticillata
(l.f.) Royle. J. Environ. Sci. Health Part A 29: 503-516. Gupta, S. K.; Chen, K. Y. (1975) Pa rtitioning of trace elements in select ive chemical fractions of nearshore

sediments. Environ. Lett. 10: 129-158.
Gustafsson, J. P.; Pechova, P.; Berggren, D. (2003) Mode ling metal binding to soils: the role of natural organic

matter. Environ. Sci. Technol. 37: 2767-2774.
Guy, R. D.; Chakrabarti, C. L. (1976) Studies of metal-or ganic interactions in model systems pertaining to natural

waters. Can. J. Chem. 54: 2600-2611.

Haack, U.; Kienholz, B.; Reimann, C.; Schn eider, J.; Stumpfl, E. F. (2004) Is otopic composition of lead in moss and
soil of the European Arctic. Geochim. Cosmochim. Acta 68: 2613-2622.

# AX7-221 Haanstra, L.; Doelman, P. (1991) An ecological dose-response model approach to short- and long-term effects of
heavy metals on arylsulfatase activity . Biol. Fertil. Soils 11: 18-23. Habibi, K. (1973) Characterization of particulate matter in vehicle exhaust. Environ. Sci. Technol. 7: 223-234.
Haering, K. C.; Daniels, W. L.; Feagly, S. E. (2000) Reclaiming mined lands with biosolids, manures, and papermill
sludges. In: Barnhisel, R. I.; Darmody, R. G.; Daniels, W. L., eds. Reclamation of drastically disturbed lands. Madison, WI: Soil Science Society of America; pp. 615-644. [Agronomy Monograph no. 41].
Hagopian-Schlekat, T.; Chandler, G. T.; Shaw, T. J. (2001) Acute toxicity of five sediment-associated metals,
individually and in a mixture, to the estuarine meiobenthic harpacticoid copepod Amphiascus tenuiremis

. Mar. Environ. Res. 51: 247-264.
Hamelin, B.; Grousset, F.; Sholkovitz, E. R. (1990) Pb isotopes in surficial pelagic sediments from the North

Atlantic. Geochim. Cosmochim. Acta 54: 37-47. Hansmann, W.; Köppel, V. (2000) Le ad-isotopes as tracers of pollutant s in soils. Chem. Geol. 171: 123-144.
Harper, P. P.; Stewart, K. W. (1984) Plecoptera. In: Merritt, R. W.; Cummins, K. W. eds. An introduction to the aquatic insects of North America. Dubuque, IA: Kendall-Hunt Publishing Company.
Hassler, C. S.; Slaveykova, V. I.; Wilkinson, K. J. (2004) Some fundamental (and often overlooked) considerations
underlying the free ion activity and biotic ligand models. Environ. Toxicol. Chem. 23: 283-291. He, P. P.; Lv, X. Z.; Wang, G. Y. (2004) Effects of Se and Zn supplementation on the antagonism against Pb and Cd
in vegetables. Environ. Int. 30: 167-172.
Healy, M. A.; Harrison, P. G.; Aslam, M.; Davis, S. S.; Wilson, C. G. (1992) Lead sulphide and traditional preparations: routes for in gestion, and solubility and reactions in gastric fluid. J. Clin. Hosp. Pharm.

7: 169-173. Henny, C. J.; Blus, L. J.; Hoffman, D. J.; Grove, R. A. ; Hatfield, J. S. (1991) Lead accumulation and osprey production near a mining site on the Coeur d'Alene River, Idaho. Arch. Environ. Contam. Toxicol.

21: 415-424. Hercules, D. M. (1970) Electron Spect roscopy. Anal. Chem. 42: 20a-40a. Herkovits, J.; Perez-Coll, C. S. (1991) Antagonism and synergism between lead and zinc in amphibian larvae.

Environ. Pollut. 69: 217-221.
Herrick, G. T.; Friedland, A. J. (1990) Patterns of trace metal concentration and acidity in montane forest soils of the

northeastern U.S. Water Air Soil Pollut. 53:151-157.
Hettiarachchi, G. M.; Pierzynski, G. M. ; Oehne, F. W.; Sonmez, O.; Ryan, J. A. (2001) In situ stabilization of soil
lead using phosphorus. J. Environ. Qual. 30: 1214-1221. Hettiarachchi, G. M.; Pierzynski, G. M. ; Oehne, F. W.; Sonmez, 0.; Ryan, J. A. (2003) Treatment of contaminated
soil with phosphorus and manganese oxide reduces lead absorption by Sprague-Dawley rats. J. Environ.
Qual. 32: 1335-1345.
Heyl, A. V.; Landis, G. P.; Zartman, R. E. (1974) Isotopic evidence for the origin of Mississippi Valley-type mineral
deposits: a review. Econ. Geol. 69: 992-1006.
Ho, M. D.; Evans, G. J. (2000) Sequen tial extraction of metal contaminated soils with radiochemical assessment of
readsorption effects. Environ. Sci. Technol. 34: 1030-1035.
Hodson, P. V.; Blunt, B. R.; Spry, D. J. (1978) Chronic toxicity of water-borne and dietary lead to rainbow trout
( Salmo gairdneri ) in Lake Ontario water. Water Res. 12: 869-878.

Hoffman, D. J.; Heinz, G. H.; Sileo, L.; Audet, D. J.; Campbell, J. K.; LeCaptain, L. J. (2000a) Developmental
toxicity of lead-contaminated sediment to mallard ducklings. Arch. Environ. Contam. Toxicol. 39: 221-232. Hoffman, D. J.; Heinz, G. H.; Sileo, L.; Audet, D. J.; Camp bell, J. K.; LeCaptain, L. J. ; Obrecht, H. H., III. (2000b)
Developmental toxicity of lead-contaminated sediment in Canada geese ( Branta Canadensis ). J. Toxicol.

Environ. Health A 59: 235-252.

Holcombe, G. W.; Benoit, D. A. ; Leonard, E. N.; McKim, J. M. (1976) Lo ng-term effects of lead exposure on three
generations of brook trout ( Salvelinus fontinalis ). J. Fish Res. Board Can. 33: 1731-1741.
Hopkin, S. P. (1989) Ecophysiology of metals in terrestrial invertebrates. London, United Kingdom: Elsevier Applied Science. (Pollution Monitoring series).
Horne, M. T.; Dunson, W. A. (1995a) Toxicity of meta ls and low pH to embryos and larvae of the Jefferson

salamander, Ambystoma jeffersonianum . Arch. Environ. Contam. Toxicol. 29: 110-114.
Horne, M. T.; Dunson, W. A. (1995b) The interactive effects of low pH, toxic metals, and DOC on a simulated
temporary pond community. Environ. Pollut. 89: 155-161. Horne, M. T.; Dunson, W. A. (1995c) Effects of low pH, metals, and water hardness on larval amphibians. Arch.

Environ. Contam. Toxicol. 29: 500-505.

# AX7-222 Houlton, B. Z.; Driscoll, C. T.; Fahey, T. J.; Likens, G. E.; Groffman, P. M.; Bernhardt, E. S.; Buso, D. C. (2003) Nitrogen dynamics in ice storm-damaged forest ecosystems: implications for nitrogen limitation theory.
Ecosystems 6: 431-443. Hršak, J.; Fugaš, M.; Vadji ć , V. (2000) Soil contamination by Pb, Zn and Cn from a lead smeltery. Environ. Monit.

Assess. 60: 359-366. Huang, J.-H.; Matzner, E. (2004) Biog eochemistry of trimethyllead and lead in a forested ecosystem in Germany.
Biogeochemistry 71: 125-139.
Hughes, J. W.; Fahey, T. J. (1994) Litterfall dynamics and ecosystem recovery during forest development. For. Ecol.
Manage. 63: 181-198. Humphreys, D. J. (1991) Effects of e xposure to excessive quantities of lead on animals. Br. Vet. J. 147: 18-30.
Hunt, A.; Johnson, D. L.; Watt, J. M.; Thornton, I. (1992) Characterizing the sources of particulate lead in house dust by automated scanning electron microscopy. Environ. Sci. Technol. 26: 1513-1523.
Impellitteri, C. (2005) Effects of pH and phosphate on metal distribution with emphasis on As speciation and mobilization in soils from a lead smelting site. Sci. Total Environ. 345: 175-190.
Ingersoll, C. G.; Haverland, P. S.; Brun son, E. L.; Canfield, T. J.; Dwyer, F. J. ; Henke, C. E.; Kemble, N. E.; Mount,
D. R.; Fox, R. G. (1996) Calculation and evaluation of sediment effect concentrations for the amphipod
( Hyalella azteca ) and the midge ( Chironomus riparius ). J. Great Lakes Res. 22: 602-623.
Isaure, M.-P.; Laboudigue, A.; Manceau, A.; Sarret, G.; Tiffreau, C.; Trocellie r, P.; Lamble, G.; Hazemann, J.-L.;
Chateigner, D. (2002) Quantitative Zn speciati on in a contaminated dredged sediment by μ -PIXE, μ -SXRF, and EXAFS spectroscopy and principal component analysis. Geochim. Cosmochim. Acta 66: 1549-1567.
Jackson, B. P.; Winger, P. V.; Lasier, P. J. (2004) At mospheric lead deposition to Okefenokee Swamp, Georgia,

USA. Environ. Pollut. 130: 445-451.

Jackson, B. P.; Williams, P. L.; Lanzirott, A.; Bertsch, P. M. (2005) Evidence for biogenic pyromorphite formation
by the nematode caenorhabditis elegans . Environ. Sci. Technol. 39: 5620-5625.
James, E. W.; Henry, C. D. (1993) Lead isotopes of ore deposits in Trans-Pecos, Texa s and northeastern Chihuahua, Mexico: basement, igneous, and sedimentary sources of metals. Econ. Geol. 88: 934-947.
Jampani, C. S. R. (1988) Lead toxicity to alga Synechococcus aeruginosus and its recovery by nutrients. J. Environ.

Biol. 9: 261-269.
Janssen, M. P. M.; Hogervorst, R. F. (1993) Metal accumulation in soil arthro pods in relation to micro-nutrients.

Environ. Pollut. 79: 181-189.
Jayaraj, Y. M.; Mandakini, M.; Nimbargi, P. M. (1992) Effect of mercury and lead on primary productivity of two

water bodies. Environ. Ecol. 10: 653-658.
Jeanroy, E.; Guillet, B. (1981) The occurrence of suspended ferruginous particles in pyrophosphate extracts of some

soil horizons. Geoderma 26: 95-105.
Jenne, E. A.; Luoma, S. N. (1977) Fo rms of trace elements in soils, sediments, and associated waters: an overview
of their determination and biological availability. In: Drucker, H.; Wildung, R. E., eds. Biological implication of metals in the envi ronmnet. Proceedings of the fifteen th annual Hanford life sciences
symposium; September-October 1975; Richland, WA. Washington, DC: Energy Research and Developmnet
Administration; pp. 110-143. Available from: NTIS, Springfield, VA; CONF-750920.

Jentschke, G.; Marschner, P.; Vodnik , D.; Marth, C.; Bredemeier, M.; Rapp , C.; Fritz, E.; Gogala, N.; Godbold,
D. L. (1998) Lead uptake by Picea abies seedlings: effects of nitrogen source and mycorrhizas . J. Plant
Physiol. 153: 97-104.
Jersak, J.; Amundson, R.; Brimhall, G., Jr. (1997) Trace me tal geochemistry in spodosols of the northeastern United
States. J. Environ. Qual. 26: 511-521.
Johansson, K.; Bringmark, E.; Lindevall, L.; Wilander, A. (1995) Effects of acidification on the concentrations of heavy metals in running waters in Sweden. Water Air Soil Pollut. 85: 779-784. Johansson-Sjöbeck, M.-L.; Larsson, Å. (1979) Effects of inorganic lead on delta-aminolevulinic dehydratase

activity and haematological variables in the rainbow trout, Salmo gairdnerii . Arch. Environ. Contam.

Toxicol. 8: 419-431.
Johnson, D.; Hale, B. (2004) White birch ( Betula papyrifera Marshall) foliar litter decomposition in relation to trace
metal atmospheric inputs at metal-contaminated and uncontaminated sites near Sudbury, Ontario and Rouyn-Noranda, Quebec, Canada. Environ. Pollut. 127: 65-72.
Johnson, C. E.; Petras, R. J. (1998) Distribution of zinc and lead fractions within a fo rest spodosol. Soil Sci. Soc.

Am. J. 62: 782-789.

Johnson, C. E.; Siccama, T. G.; Dris coll, C. T.; Likens, G. E.; Moeller, R. E. (1995a) Changes in lead
biogeochemistry in response to decreasing atmospheric inputs. Ecol. Appl. 5: 813-822.

# AX7-223 Johnson, C. E.; Driscoll, C. T.; Fahey, T. J.; Siccama, T. G.; Hughes, J. W. (1995b) Carbon dynamics following
clear-cutting of a northern hardwood forest. In: Kelly, J. M.; McFee, W. W., eds. Carbon forms and function in forest soils. Madison, WI: Soil Science Society of America; pp. 463-488.
Johnson, C. E.; Petras, R. J.; April, R. H.; Siccama, T. G. (2004) Post-glacial lead dynamics in a forest soil. Water

Air Soil Pollut. 4: 579-590. Jones, K. C.; Johnston, A. E. (1991) Significance of atmosphe ric inputs of lead to grassland at one site in the United
Kingdom since 1869. Environ. Sci. Technol. 25: 1174-1178.
Jordan, M. J. (1975) Effects of zinc smelter emissions and fire on a chestnut-oak woodland. Ecology 56: 78-91.
Kabata-Pendias, A.; Pendias, H. (1992) Trace elements in soils and plants. 2n d ed. Boca Raton, FL: CRC Press, Inc.
Kapustka, L. A.; Lipton, J.; Galbraith , H.; Cacela, D.; Lejeune, K. (1995) Metal and arsenic impacts to soils,
vegetation communities, and wildlife habitat in sout hwest Montana uplands contaminated by smelter emissions: II. Laboratory phytotoxicity studies. Environ. Toxicol. Chem. 14: 1905-1912.
Kapustka, L. A.; Clements, W. H.; Ziccardi, L.; Paquin, P. R.; Sprenger, M.; Wall, D. (2004) Issue paper on ecological effects of metals. Submitted to U.S. EP A, Risk Assessment Forum. Contract Number

#68-C-98-148. Karamanos, R. E.; Bettany, J. R.; Rennie, D. A. (1976) Extractability of added lead in soils using lead-210. Can.

J. Soil Sci. 56: 37-42.
Kaste, J.; Friedland, A.; Stürup, S. (2003) Using stable and ra dioactive isotopes to trace atmospherically deposited

Pb in montane forest soils. Environ. Sci. Technol. 37: 3560-3567.

Kaste, J. M.; Friedland, A. J.; Miller, E. K. (2005) Potentially mobile lead fractions in montane organic-rich soil

horizons. Water Air Soil Pollut. 167: 139-154.
Keeney, W. L.; Breck, W. G.; VanLoon , G. W.; Page, J. A. (1976) The determination of trace metals in Cladophora
glomerata - C. glomerata as a potential biological monitor. Water Res. 10: 981-984.

Keon, N. E.; Swartz, C. H.; Brabander, D. J.; Harvey, C.; Hemond, H. F. (2001) Validation of an arsenic sequential
extraction method for evaluation mobility in sediments. Environ. Sci. Technol. 35: 2778-2784.
Ketterer, M. E.; Peters, M. J.; Tisdale, P. J. (1991) Veri fication of a correction procedure for measurement of lead
isotope rations by inductively coupled plasma mass spectrometry. J. Anal. At . Spectrom. 6: 439-443. Ketterer, M. E.; Lowry, J. H.; Simon, J.; Humphries, K. ; Novotnak, M. P. (2001) Lead isotopic and chalcophile element compositions in the environment near a zinc sm elting-secondary zinc recovery facility, Palmerton,
Pennsylvania, USA. Appl. Geochem. 16: 207-229.
Khan, D. H.; Frankland, B. (1983) Effects of cadmium and lead on radish plants with particular reference to movement of metals through soil profile and plant. Plant Soil 70: 335-345.
Khangarot, B. S. (1991) Toxicity of metals to a freshwater tubificid worm, Tubifex tubifex (Muller). Bull. Environ.

Contam. Toxicol. 46: 906-912.
Kheboian, C.; Bauer, C. F. (1987) Accu racy of selective extraction procedures for metal speciation in model aquatic

sediments. Anal. Chem. 59: 1417-1423. Kim, G.; Hussain, N.; Scudlark, J. R.; Church, T. M. (2000) Factors influencing the atmospheric depositional fluxes
of stable Pb, 210Pb, and 7Be into Chesap eake Bay. J. Atmos. Chem. 36: 65-79.
Kim, S.-J.; Rodriguez-Lanetty, M.; Suh, J.-H.; Song, J.-I. (2003) Emergent effects of heavy metal pollution at a population level: Littorina brevicula a case study. Mar. Pollut. Bull. 46: 74-80.
Klaminder, J.; Bindler, R.; Emteryd, O.; Renberg, I. (2005) Uptake and recycling of lead by boreal forest plants:
quantitative estimates from a site in northern Sweden. Geochim. Cosmochim. Acta 69: 2485-2496. Klaminder, J.; Bindler, R.; Emteryd, O.; Appleby, P.; Grip, H. (2006) Estimating the mean residence time of lead in
the organic horizon of boreal forest soils using 210-lead, stable lead an d a soil chronosequence.
Biogeochemistry 78: 31-49. Knowlton, M. F.; Boyle, T. P.; Jones, J. R. (1983) Uptake of lead from aquatic sediment by submersed macrophytes
and crayfish. Arch. Environ. Contam. Toxicol. 12: 535-541.
Koch, D. M.; Jacob, D. J.; Graustein, W. C. (1996) Verti cal transport of tropospheric aerosols as indicated by 7Be and 210Pb in a chemical tracer model. J. Geophys. Res. (Atmos.) 101: 18651-18666.

Köck, G.; Triendl, M.; Hofer, R. (1996) Seasonal patterns of meta l accumulation in Arctic char ( Salvelinus alpinus ) from an oligotrophic Alpine lake related to temperature. Can. J. Fish. Aquat. Sci. 53: 780-786. Kraak, M. H. S.; Wink, Y. A.; Stuijf zand, S. C.; Buckert-de Jong, M. C.; de Groot, C. J.; Admiraal, W. (1994)
Chronic ecotoxicity of Zn and Pb to the zebra mussel Dreissena polymorpha . Aquat. Toxicol. 30: 77-89.

Kruatrac hue, M.; Jarupan, W.; Chitramvong, Y. P.; Poketh itiyook, P.; Upatham, E. S.; Parkpoomkamol, K. (2002)
Combined effects of lead and humic acid on growth and lead uptake of duckweed, Lemna minor . Bull.

Environ. Contam. Toxicol. 69: 655-661.

# AX7-224 Krüger, F.; Gröngröft, A. (2003) The di fficult assessment of heavy metal contamination of soils and plants in Elbe
River floodplains. Acta Hydrochim. Hydrobiol. 31: 436-443. Kuperman, R. G.; Carreiro, M. M. (1997) Soil heavy meta l concentrations, microbial biomass and enzyme activities
in a contaminated grassland ecosystem. Soil Biol. Biochem. 29: 179-190.
Kutlu, M.; Susuz, F. (2004) The eff ects of lead as an environmenta l pollutant on EROD enzyme in Gammarus pulex
(L.) (Crustacea: Amphipoda) . Bull. Environ. Contam. Toxicol. 72: 750-755.
Lamy, I.; Bourgeois, S.; Bermond, A. (1993) Soil cadmium mobility as a consequence of sewage sludge disposal.
J. Environ. Qual. 22: 731-737. Lang, F.; Kaupenjohann, M. (2003) Effect of dissolved organic matter on the precipitation and mobility of the lead
compound chloropyromorphite in solution. Eur. J. Soil Sci. 54: 139-147.
Laperche, V.; Traina, S. J.; Gaddam, P.; Logan, T. J. (1996) Chemical and mineralogical characterizations of Pb in a

contaminated soil: reactio ns with synthetic apatite. Enviro n. Sci. Technol. 30: 3321-3326.
Larsen, V. J. (1983) The significance of atmospheric deposition of heavy metals in four Danish lakes. Sci. Total

Environ. 30: 111-127.
Laskowski, R.; Marya ń ski, M.; Nikli ń ska, M. (1994) Effect of heavy-metals and mineral nutrients on forest litter
respiration rate. Environ. Pollut. 84: 97-102. Laskowski, R.; Marya ń ski, M.; Nikli ń ska, M. (1995) Changes in the chemical composition of water percolating
through the soil profile in a moderately polluted catchment. Water Air Soil Pollut. 85: 1759-1764.

Leach, D. L.; Hofstra, A. H.; Church , S. E.; Snee, L. W.; Vaughn, R. B. ; Zartman, R. E. (1998) Evidence for proterozoic and late cretaceous-early tertiary ore-forming events in th e Coeur D'Alene district, Idaho and

Montana. Econ. Geol. 93: 347-359.

Lee, B.-G.; Griscom, S. B.; Lee, J.-S.; Choi, H. J.; Koh, C.-H.; Luoma, S. N.; Fisher, N. S. (2000) Influences of dietary uptake and reactive sulfides on metal bioavaila bility from aquatic sediments. Science 287: 282-284.
Lefcort, H.; Meguire, R. A.; Wilson, L. H.; Ettinge, W. F. (1998) Heavy metals alter the survival, growth,
metamorphosis, and antipredatory behavior of Columbia spotted frog ( Rana luteiventris ) tadpoles. Arch.

Environ. Contam. Toxicol. 35: 447-456.

Lefcort, H.; Thomson, S. M.; Cowles, E. E.; Harowicz, H. L.; Livaudais, B. M.; Roberts, W. E.; Ettinger, W. F.
(1999) Ramifications of predator avoidance: predator and heavy-metal-mediated competition between tadpoles and snails. Ecol. Appl. 9: 1477-1489.
Lefcort, H.; Ammann, E.; Eiger, S. M. (2000) Antipredatory behavior as an index of heavy-metal pollution? A test
using snails and caddisflies. Arch. Environ. Contamin. Toxicol. 38: 311-316.

Lefcort, H.; Abbott, D. P.; Cl eary, D. A.; Howell, E.; Kellar, N. C.; Smith, M. M. (2004) Aquatic snails from mining
sites have evolved to detect and avoid heavy metals. Arch. Environ. Contam. Toxicol. 46: 478-484.

Leita, L.; De Nobili, M.; Pardini, G.; Fe rrari, F.; Sequi, P. (1989) Anomolous contents of heavy metals in soils and
vegetation of a mine area in S.W. Sardinia, Italy. Water Air Soil Pollut. 48: 423-433.
Lenoble, V.; Laclautre, C.; Deluchat, V.; Serpaud, B.; Bolli nger, J. C. (2005) Arsenic removal by adsorption on iron (III) phosphate. J. Hazard. Mat. B 123: 262-268.
Lewis, T. E.; McIntosh, A. W. (1986) Uptake of sediment-bound lead and zinc by the freshwater isopod Asellus

communis at three different pH levels. Arch. Environ. Contam. Toxicol. 15: 495-504.Li, W.-H.; Chan, P. C. Y.; Chan, K. M. (2004) Metal uptake in zebrafish embryo-larvae exposed to metalcontaminated sediments. Mar. Environ. Res. 58: 829-832.
Liang, C. N.; Tabatabai, M. A. (1977) Effects of trace elements on nitrogen mineralisation in soils. Environ. Pollut.

12: 141-147. Liang, C. N.; Tabatabai, M. A. (1978) Effects of trace elements on nitrification in soils. J. Environ. Qual.

7: 291-293. Likens, G. E., ed. (1989) Long-term studies in ecology: appr oaches and alternatives. Papers from the Second Cary
Conference; May, 1987; Millbrook, NY. New York, NY: Spri nger-Verlag, Inc.
Likens, G. E.; Bormann, F. H.; Johnson, N. M. (1969) Nitrification: importance to nutrient losses from a cutover forested ecosystem. Science (Washington, DC) 163: 1205-1206.
Likens, G. E.; Driscoll, C. T.; Buso, D. C. (1996) Long-term effects of acid rain: response and recovery of a forest
ecosystem. Science (Washington, DC) 272: 244-246.
Lin, Q.; Chen, Y. X.; He, Y. F.; Tian, G. M. (2004) Root-i nduced changes of lead availability in the rhizosphere of
Oryza sativa L. Agric. Ecosyst. Environ. 104: 605-613.

Linton, R. W.; Natusch, D. F. S.; Solomon, R. L.; Evans, C. A., Jr. (1980) Physicochemi cal characterization of lead
in urban dusts. A microanalytical approach to lead tracing. Envi ron. Sci. Technol. 14: 159-164.

# AX7-225 Little, P.; Martin, M. H. (1972) A survey of zinc, lead and cadmium in soil and natural vegetation around a smelting
complex. Environ. Pollut. 3: 241-254. Liu, J.; Li, K.; Xu, J.; Zhang, Z.; Ma, T.; Lu, X.; Yang, J.; Zhu, Q. (2003) Lead toxicity, uptake, and translocation in

different rice cultivars. Plant Sci. 165: 793-802.
Lock, K.; Janssen, C. R. (2002) Multi-generation toxicity of zinc, cadmium, copper and lead to the potworm
Enchytraeus albidus . Environ. Pollut. 117: 89-92.
Long, D. T.; Angino, E. E. (1977) Chemical speciation of Cd, Cu, Pb, and Zn, in mixed freshwater, seawater, and

brine solutions. Geochim. Cosmochim. Acta. 41:1183-1191. Long, E. R.; MacDonald, D. D.; Smith, S. L.; Calder, F. D. (1995 ) Incidence of adverse bi ological effects within
ranges of chemical concentrations in marine and estuarine sediments. Environ. Manage. 19: 81-97.
Long, E. R.; MacDonald, D. D.; Cubbag e, J. C.; Ingersoll, C. G. (1998) Predicting the toxicity of sedimentassociated trace metals with simu ltaneously extracted trace metal : acid- volatile sulfide concentrations and
dry weight-normalized concentrations: a critical co mparison. Environ. Toxicol. Chem. 17: 972-974. Long, E. R.; Ingersoll, C. G.; MacDonald, D. D. (2006) Calculation and uses of mean sediment quality guideline
quotients: a critical review. Environ. Sci. Technol. 40: 1726-1736.
Lotter, A. F.; Appleby, P. G.; Bindler , R.; Dearing, J. A.; Grytnes, J.-A.; Hofmann, W.; Kamenik, C.; Lami, A.; Livingstone, D. M.; Ohlendorf, C.; Ro se, N.; Sturm, M. (2002) The sediment record of the past 200 years in
a Swiss high-alpine lake: Hagelseewli (233 9 m a.s.l.) J. Paleolimnol. 28: 111-127.
Lovering, T. G., ed. (1976) Lead in the environment. Washington, DC: U.S. Department of the Interior, Geological Survey; Geological Survey professional paper no. 957. Available from: GPO, Washington, DC;

S/N 024-001-02911-1. Lumsdon, D. G.; Evans, L. J. (1995) Predicting chemical speciation and computer simulation. In: Ure, A. M.; Davidson, C. M., eds. Chemical speciation in th e environment. London, United Kingdom: Blackie
Academic and Professional; pp. 86-134.
Luoma, S. N.; Rainbow, P. S. (2 005) Why is metal bioaccumulation so variable? Biodynamics as a unifying concept. Environ. Sci. Technol. 39: 1921-1931.
Ma, W.-C. (1996) Lead in mammals. In: Beyer, W. N.; Heinz, G. H.; Redmon-Norwood, A. W., eds. Environmental
contaminants in wildlife: interpreting tissue c oncentrations. Boca Raton, FL: CRC Press. [SETAC
Foundation for Environmental Education series].
Ma, Y. B.; Uren, N. C. (1995) Application of new fractio nation scheme for heavy metals in soils. Commun. Soil Sci.

Plant Anal. 26: 3291-3303. Ma, Q. Y.; Logan, T. J.; Traina, S. J. (1995) Lead immobilization from aqueous solutions and contaminated soils
using phosphate rocks. Environ. Sci. Technol. 29: 1118-1126. MacDonald, D. D.; Ingersoll, C. G.; Berger, T. A. (2000) Development and evaluation of consensus-based sediment
quality guidelines for freshwater ecosystems. Arch. Environ. Contam. Toxicol. 39: 20-31.

MacDonald, A.; Silk, L.; Schwartz, M.; Playle, R. C. (2002) A lead-gill binding model to predict acute lead toxicity
to rainbow trout ( Oncorhynchus mykiss ). Comp. Biochem. Physiol. Part C: Toxicol. Pharmacol.

133C: 227-242. Mackie, G. L. (1989) Tolerances of five benthic invertebrates to hydrogen ions and metals (Cd, Pb, Al). Arch.

Environ. Contam. Toxicol. 18: 215-223.
MacLean, R. S.; Borgmann, U.; Dixon, D. G. (1996) Bioaccumulation kinetics and toxicity of lead in Hyalella

azteca (Crustacea, Amphipoda). Can. J. Fish. Aquat. Sci. 53: 2212-2220. Maddock, B. G.; Taylor, D. (1980) The acute toxicity and bioaccumulation of some lead alkyl compounds in marine

animals. In: Branica, M.; Konrad, Z., eds. Lead in the marine environment. Oxford, United Kingdom:
Pergamon Press; pp. 233-261. Maenhaut, W. (1987) Particle-induced x-ray emission spectrometry: an accurate technique in the analysis of
biological environmental and geological samples. Anal. Chim. Acta. 195: 125-140.
Maginn, S. J. (1998) Analytical applications of synchrotron radiation. Analyst 123: 19-29.
Mahler, B. J.; Van Metre, P. C.; Callender, E. (2006) Trends in metals in urban and reference lake sediments across

the United States, 1970 to 2001. Environ. Toxicol. Chem. 25: 1698-1709.
Malcová, R.; Gryndler, M. (2003) Amelioration of Pb and Mn toxicity to arbuscular mycorrhizal fungus Glomus

intraradices by maize root exudates. Biol. Plant. 47: 297-299.

Manceau, A.; Boisset, M.; Sarret, G.; H azemann, J.; Mench, M.; Cambier, P.; Pr ost, R. (1996) Direct determination of lead speciation in contaminated soils by EXAFS spectroscopy. Environ. Sci. Technol. 30: 1540-1552.

# AX7-226 Manceau, A.; Lanson, B.; Schlegel, M. L.; Hargé, J. C.; Mu sso, M.; Eybert-Bérard, L.; H azemann, J.-L.; Chateigner,
D.; Lamble, G. M. (2000a) Quantitative Zn speciation in smelter-contaminated soils by EXAFS spectroscopy. Am. J. Sci. 300: 289-343.
Manceau, A.; Schlegel, M. L.; Musso, M.; Sole, V. A.; Gauthier, C.; Petit, P. E.; Trolard, F. (2000b) Crystal
chemistry of trace elements in natural and synthetic goethite. Geochim. Cosmochim. Acta 64: 3643-3661.
Manceau, A.; Lanson, B.; Drits, V. A. (2 002) Structure of heavy metal sorbed birnessite. Part III: results from
powder and polarized extended x-ray absorption fine structure spectroscopy. Geochim. Cosmochim. Acta

66: 2639-2663. Mannio, J. (2001) Responses of headwater lakes to air pollution changes in Finland. Monogr. Boreal Environ.

Res. 18: 1-42. Maret, T. R.; Cain, D. J.; MacCoy, D. E.; Short, T. M. (2003) Response of benthic invertebrate assemblages to metal exposure and bioaccumulation associated with hard-rock mining in northwestern streams, USA. J. N. Am.

Benthol. Soc. 22: 598-620. Marinussen, M. P. J. C.; Van der Zee, S. E. A. T. M.; de Haan, F. A. M.; Bouwman, L. M.; Hefting, M. M. (1997)
Heavy metal (copper, lead, and zinc) accumulation and excretion by the earthworm, Dendrobaena veneta . J.
Environ. Qual. 26: 278-284.Marschner, P.; Godbold, D. L.; Jentschke, G. (1996) Dynamics of lead accumulation in mycorrhizal and nonmycorrhizal Norway spruce ( Picea abies (L.) Karst.). Plant Soil 178: 239-245.
Marschner, P.; Klam, A.; Jentschke, G.; Godbold, D. L. (1999) Aluminium and lead tolerance in ectomycorrhizal fungi. J. Plant Nutr. Soil Sci. 162: 281-286.
Marsh, A. S.; Siccama, T. G. (1997) Use of formerly plowed land in New England to monitor the vertical
distribution of lead, zinc and copper in mineral soil. Water Air Soil Pollut. 95: 75-85. Martin, R. B. (1986) Bioinorganic chemistry of metal ion toxicity. In: Sigel, H., ed. Concepts on metal ion toxicity.
New York, NY: Marcel Dekker; pp. 21-66. (Metal ions in biological systems: v. 20).
Martin, M. H.; Bullock, R. J. (1994) The impact and fate of heavy metals in an oak woodland ecosystem. In: Ross, S. M., ed. Toxic metals in soil-plant systems. Ch ichester, England: John Wiley & Sons; pp. 327-365.
Mateo, R.; Hoffman, D. J. (2001) Differences in oxidative stress between young Canada geese and mallards exposed

to lead-contaminated sediment. J. Toxicol. Environ. Health Part A 64: 531-545.
Mateo, R.; Beyer, W. N.; Spann, J. W.; Hoffman, D. J. (2003a) Relation of fatty acid composition in lead-exposed
mallards to fat mobilization, lipid peroxidation and alkaline phosphatase activity. Comp. Biochem. Physiol.

C Pharmacol. Toxicol. 135: 451-458. Mateo, R.; Beyer, W. N.; Spann, J. W.; Hoffman, D. J.; Ramis, A. (2003b) Relationship between oxidative stress,
pathology, and behavioral signs of lead poisoning in mallards. J. Toxicol. Environ. Health A 66: 1371-1389.
McBride, M. B.; Richards, B. K.; Steenhuis, T.; Russo, J. J.; Suavé, S. (1997) Mobility and solubility of toxic metals
and nutrients in soil fifteen years after sl udge application. Soil Sci. 162: 487-500.

McBride, M. B.; Richards, B. K.; Steenhuis, T. Spiers, G. (1999) Long-term leaching of trace elements in a heavily sludge-amended silty clay loam soil. Soil Sci. 164: 613-624.
McCarthy, J. F. (1989) Bioavailability and toxicity of me tals and hydrophobic organic contaminants. In: Suffet,
I. H.; MacCarthy, P., eds. Aquatic humic substances: influence on fate and treatment of pollutants. Washington, DC: American Chemical Society; pp. 263-277. (Advances in chemistry series no. 219).
McCrea, A. R.; Trueman, I. C.; Fullen, M. A. (2004) Factor s relating to soil fertility and species diversity in both

semi-natural and created meadows in the west midl ands of England. Eur. J. Soil Sci. 55: 335-348. Merino, A.; García-Rodeja, E. (1997) Heavy metal and alum inium mobilization in soils from Galicia (NW spain) as
a consequence of experimental acidification. Appl. Geochem. 12: 225-228.
Merlini, M.; Pozzi, G. (1977) Lead and freshwater fishes: part 1—lead accumulation and water pH. Environ. Pollut.

12: 167-172. Meyer, J. S.; Adams, W. J.; Brix, K. V.; Luoma, S. N.; Mount, D. R.; Stu bblefield, W. A.; Wood, C. M. (2005)
Toxicity of dietborne metals to aquatic organisms. Pensacola, FL: Society of Environmental Toxicology and Chemistry.
Migon C.; Journel, B.; Nicolas, E. (1 997) Measurement of trace metal wet, dr y and total atmospheric fluxes over the
ligurian sea. Atmos. Environ. 31: 889-896.
Miller, E. K.; Friedland, A. J. (199 4) Lead migration in forest soils: response to changing atmospheric inputs.

Environ. Sci. Technol. 28: 662-669. Miller, T. G.; Mackay, W. C. (1980) The effects of hardne ss, alkalinity and pH of test water on the toxicity of
copper to rainbow trout ( Salmo gairdneri ). Water Res. 14: 129-133.

# AX7-227 Miller, W. P.; McFee, W. W. (1983) Distribution of cadm ium, zinc, copper, and lead in soils of industrial
northwestern Indiana. J. Environ. Qual. 12: 29-33.

Miller, E. K.; Friedland, A. J. ; Arons, E. A.; Mohnen , V. A.; Battles, J. J.; Panek, J. A.; Kadlecek, J.; Johnson, A. H.
(1993) Atmospheric deposition to forests along an elev ational gradient at Whiteface-Mountain, NY, USA.

Atmos. Environ. 27: 2121-2136. Millward, R. N.; Carman, K. R.; Fleeger, J. W.; Gambrell, R. P.; Powell, R. T.; R ouse, M.-A. (2001) Linking
ecological impact to metal concentrations and speci ation: a microcosm experiment using a salt marsh
meiofaunal community. Environ. Toxicol. Chem. 20: 2029-2037. Miranda, M. G.; Ilangovan, K. (1996) Uptake of lead by Lemna gibba L.: influence on specific growth rate and
basic biochemical changes. Bull. Environ. Contam. Toxicol. 56: 1000-1007.

Mitchell, M. J.; Driscoll, C. T. ; Kahl, J. S.; Likens, G. E.; Murdoch, P. S.; Pardo, L. H. (1996) Climatic control of

nitrate loss from forested watershe ds in the northeast United States. Environ. Sci. Technol. 30: 2609-2612.
Mize, S. V.; Deacon, l. R. ( 2002) Relations of benthic m acroinvertebrates to concentr ations of trace elements in water, streambed sediments, and transplanted bryophy tes and stream habitat conditions in nonmining and
mining areas of the Upper Colorado River Basin, Colorado, 1995-98. Denver, CO: U.S. Geological Survey;
Water-Resources Investigations Report 02-4139. Available: http://pubs.usgs.gov/wri/wri024139/pdf/WRI02-4139.pdf [24 October, 2005].
Monna, F.; Othman, D. B.; Luck, J. M. (1995) Pb isotopes an d Pb, Zn and Cd concentrations in the rivers feeding a
coastal pond (Thau, southern France): constraints on the origin(s) and flux(es) of metals. Sci. Total Environ.

166: 19-34. Moore, H. E.; Poet, S. E. (1976) 210Pb fluxes determined from 210Pb and 226Ra soil profiles. J. Geophys. Res.
(Oceans and Atmos.) 81: 1056-1058. Morel, F. (1983) Principles of Aquatic Chem istry. New York, NY: John Wiley and Sons.
Morelli, E.; Scarano, G. (2001) Synthesis and stability of phytochelatins induced by cadmium and lead in the marine

diatom Phaeodactylum tricornutum . Mar. Environ. Res. 52: 383-395. Morgan, J. E.; Morgan, A. J. (1988) Earthworms as biol ogical monitors of cadmium, copper, lead and zinc in

metalliferous soils. Environ. Pollut. 54: 123-138.

Mount, D. I.; Barth, A. K.; Garrison, T. D.; Barten, K. A. ; Hockett, J. R. (1994) Dietary and waterborne exposure of
rainbow trout ( Oncorhynchus mykiss ) to copper, cadmium, lead and zinc using a live diet. En viron. Toxicol.

Chem. 13: 2031-2041.

Mucha, A. P.; Vasconcelos M. T. S. D.; Bordalo A. A. (2003) Macrobenthic community in the Douro estuary:

relations with trace metals and natural sediment characteristics. Environ. Pollut. 121: 169-180.
Murray, K. S.; Rogers, D. T.; Kaufman, M. M. (2004) Heavy metals in an urban watershed in southeastern Michigan. J. Environ. Qual. 33: 163-172.
Nakagawa, H.; Nakagawa, K.; Sato, T. (1995a) Evaluation of erythrocyte 5-aminolevulinic acid dehydratase activity
in the blood of carp Cyprinus carpio as an indicator in fish with water lead pollution. Fish. Sci. 61: 91-95. Nakagawa, H.; Sato, T.; Kubo, H. (1995b) Evaluation of chronic toxicity of water lead for carp ( Cyprinus carpio ) using its blood 5-aminolevulinic acid dehydratase. Fish. Sci. 61: 956-959.
National Research Council of Canada. (1973) Lead in the Canadian Environment. Ottawa, Canada: National

Research Council of Canada; NRCC no.13682; Envi ronmental Secretariat publication BY73-7 (ES).
National Research Council (NRC), Committee on Bioavailability of Contaminants in Soils and Sediments. (2002)
Bioavailability of contaminants in soil and sediments: processes, tools and applications. Washington, DC:

National Academies Press.

Nelson, Y. W.; Lo, W.; Lion, L. W.; Shuler, M. L.; Ghiors e, W. C. (1995) Lead distribution in a simulated aquatic

environment: effects of bacterial biofilms and iron oxide. Water Res. 29: 1934-1944. Neuhauser, E. F.; Loehr, R. C.; Milligan, D. L.; Malecki, M. R. (1985) Toxicity of metals to the earthworm Eisenia foetida . Biol. Fertil. Soils 1: 149-152.

Neuhauser, E. F.; Cukic, Z. V.; Malecki, M. R.; Loehr, R. C.; Durkin, P. R. (1995) Bioconcentration and biokinetics of heavy metals in the earthworm. Environ. Pollut. 89: 293-301.
Newhook, R.; Hirtle, H.; Byme, K.; Meek, M.E. (2003) Releases from copper sm elters and refmeries and zinc plants
in Canada: human health exposure and risk characterization. Sci. Total Environ. 301: 23-41. Newman, M. C.; Dixon, P. M.; Looney, B. B.; Pinder, J. E., III. (1989) Estimating mean and variance for
environmental samples with below detection limit observations. Water Resour. Bull. 25: 905-910.

Nikli ń sk a, M.; Laskowski, R.; Marya ń ski, M. (1998) Effect of heavy metals and storage time on two types of forest
litter: basal respiration rate and exchangeable metals. Ecotoxicol. Environ. Saf. 41: 8-18.

# AX7-228 Niyogi, S.; Wood, C. M. (2003) Effects of chronic waterborne and dietary metal exposures on gill metal-binding:
implications for the Biotic Ligand Model (BLM). Hum. Ecol. Risk Assess. 9: 813-846. Niyogi, S.; Wood, C. M. (2004) Biotic ligand model, a flexible tool for developing site-specific water quality
guidelines for metals. Environ. Sci. Technol. 38: 6177-6192.
Nolan, A. L.; McLaughlin, M. J.; Mason, S. D. (2003) Chemical speciation of Zn, Cd, Cu, and Pb in pore waters of agricultural and contaminated soils using Donnan dialysis. Environ. Sci. Technol. 37: 90-98.
Norwood, W. P.; Borgmann, U.; Dixon, D. G.; Wallace, A. (2003) Effect s of metal mixtures on aquatic biota: a

review of observations and methods. Hum. Ecol. Risk Assess. 9: 795-811. Nouri, P. A.; Reddy, G. B. (1995) Influence of acid-rain and ozone on soil heavy metals under loblolly-pine trees: a
field-study. Plant Soil 171: 59-62.
Nozaki, Y.; DeMaster, D. J.; Lewis, D. M.; Turekian, K. K. (1978) Atmospheric 210Pb fluxes determined from soil profiles. J. Geophy s. Res. (Oceans Atmos.) 83: 4047-4051. Nriagu, J. O. (1973) Lead orthophosphates—II. Stability of chloropyromorphite at 25° C. Geochim. Cosmochim.

Acta 38: 367-377. Nriagu, J. O. (1974) Lead orthophosphates—IV. Formation and stability in environment. Geochim. Cosmochim.

Acta 38: 887-898. Nriagu, J. O.; Lawson, G.; Wong, H. K. T.; Cheam, V. (1996) Dissolved trace metals in lakes Superior, Erie, and

Ontario. Environ. Sci. Technol. 30: 178-187.
Nursita, A. I.; Singh, B.; Lees, E. (2005) The effects of cadmium, copper, lead, an d zinc on the growth and reproduction of Proisotoma minuta Tullberg (Collembola). Ecotoxicol. Environ. Saf. 60: 306-314.
Nyberg, K.; Vuorenmaa, J.; Rask, M.; Ma nnio, J.; Raitaniemi, J. (2001) Patterns in water quality and fish status of

some acidified lakes in southern Fi nland during a decade: recovery pro ceeding. Water Air Soil Pollut. 130:

1373-1378. O'Shea, T. A.; Mancy, K. H. (1978) The effect of pH and hardness metal ions on the competitive interaction
between trace metal ions and inorganic and organic complexing agents found in natural waters. Water Res.

12: 703-711. Odum, E. P. (1971) Fundamentals of ecology. 3rd ed. Philadelphia, PA: W. B. Saunders Company;
pp. 1-38, 106-136. Olson, K. W.; Skogerboe, R. K. (1975) Identification of soil lead compounds from automotive sources. Environ. Sci.

Technol. 9: 227-230.
Ostergren, J. D.; Trainor, T. P.; Bargar, J. R.; Brown, G. E.; Parks, G. A. (2000a) Inorganic ligand effects on Pb(II) sorption to goethite ( α - FeOOH) - I. Carbonate. J. Colloid Interface Sci. 225: 466-482.
Ostergren, J. D.; Trainor, T. P.; Bargar, J. R.; Brown, G. E.; Parks, G. A. (2000b) Inorganic ligand effects on Pb(II) sorption to goethite ( α -FeOOH) - II. Sulfate. J. Collo id. Interface Sci. 225: 483-493. Outridge, P. M. (2000) Lead biogeochemistry in the littora l zones of south-central Onta rio Lakes, Canada, after the
elimination of gasoline lead additives. Water Air Soil Pollut. 118: 179-201. Ownby, D. R.; Galvan, K. A.; Lydy, M. J. (2005) Lead and zinc bioavailability to Eisnia fetida after phosphorus
amendment to repository soils. Environ. Pollut. 136: 315-321.

Pa č es, T. (1998) Critical loads of trace me tals in soils: a method of calculation. Water Air Soil Pollut. 105: 451-458. Pagenkopf, G. K. (1983) G ill surface interaction model for trace-metal toxicity to fishes: role of complexation, pH,

and water hardness. Environ. Sci. Technol. 17: 342-347.
Pagenkopf, G. K. (1986) Metal ion speci ation and toxicity in aquatic systems. In: Sigel, H., ed. Concepts on metal ion toxicity. New York, NY: Marcel Dekker; pp. 101-118. (Metal ions in biological systems: v. 20). Påhlsson, A.-M. B. (1989) Toxicity of heavy metals (Zn, Cu, Cd, Pb) to vascular plants. Water Air Soil Pollut.

47: 287-319. Palmborg, C.; Bringmark, L.; Bringmark, E.; Nordgren, A. (1998) Multivariate analysis of microbial activity and
soil organic matter at a forest site subjected to low-level heavy metal contamination. Ambio 27: 53-57.
Papp, C. S. E.; Filipek, L .H.; Smith, K. S. (1991) Selectiv ity and effectiveness of extractants used to release metals associated with organic-matter. Appl. Geochem. 6: 349-353.
Paquin, P. R.; Gorsuch, J. W.; Apte, S. ; Batley, G. E.; Bowles, K. C.; Campbell, P. G. C.; Delos, C. G.; Di Toro,
D. M.; Dwyer, R. L.; Galvez, F.; Ge nsemer, R. W.; Goss, G. G.; Hogstran d, C.; Janssen, C. R.; McGeer, J. C.; Naddy, R. B.; Playle, R. C.; Santore, R. C.; Schneider, U.; Stu bblefield, W. A.; Wood, C. M.; Wu,
K. B. (2002) The biotic ligand model: a historical overview. Comp. Biochem. Physiol. C 133: 3-35. Patra, M.; Bhowmik, N.; Bandopadhyay, B.; Sharma, A. (2 004) Comparison of mercury, lead and arsenic with
respect to genotoxic effects on plant systems and the development of genetic tolerance. Environ. Exper. Bot.

52: 199-223.

# AX7-229 Pattee, O. H.; Pain, D. J. (2003) Lead in the environm ent. In: Hoffman, D. J.; Rattner, B. A.; Burton, G. A.,
Jr.; Carins, K., Jr. Handbook of ecotoxicology. Boca Raton, Fl. Lewis Publishers. pp. 373-408. Perämäki, P.; Itämies, J.; Karttunen, V.; Lajunen, L. H. J. ; Pulliainen, E. (1992) Influence of pH on the accumulation
of cadmium and lead in earthworms ( Aporrectodea caliginosa ) under controlled conditions. Ann. Zool.

Fenn. 29: 105-111. Perottoni, J.; Meotti, F.; Folmer, V.; Pivetta, L.; Nogueira, C. W.; Zeni, G. ; Rocha, J. B. (2005) Ebselen and
diphenyl diselenide do not change the inhibitory eff ect of lead acetate on delta-a minolevulinate dehidratase.

Environ. Toxicol. Pharmacol. 19: 239-248. Phillips, D. L.; Gregg, J. W. (2003) Source partitioning using stable isotopes: coping with too many sources.
Oecologia 136: 261-269.
Phillips, C.; Gy ő ri, Z.; Kovács, B. (2003) The effect of adding cadmium and lead alone or in combination to the diet of pigs on their growth, carcase composition and re production. J. Sci. Food Agric. 83: 1357-1365.
Piegorsch, W. W.; Weinberg, C. R.; Margolin, B. H. ( 1988) Exploring simple independent action in multifactor tables of proportions. Biometrics 44: 595-603.
Pirrone, N.; Glinsorn, G.; Keeler, G. J. (1995) Ambient levels and dry deposition fluxes of mercury to lakes Huron,

Erie and St. Clair. Water Air Soil Pollut. 80: 179-188. Pižl, V.; Josens, G. (1995) Earthworm communities along a gradient of urbanization. Environ. Pollut. 90: 7-14.

Planchon, F. A. M.; Van De Velde, K.; Rosman, K. J. R.; Wolff, E. W.; Ferrari, C. P.; Boutron, C. F. (2002) One
hundred fifty-year record of lead isotopes in Antarctic snow from Coats Land. Geochim. Cosmochim. Acta

67: 693-708. Playle, R. C. (2004) Using multiple metal-gill binding models and the toxic unit concept to help reconcile multiplemetal toxicity results. Aquat. Toxicol. 67: 359-370. Polissar, A. V.; Hopke, P. K.; Poirot, R. L. (2001) Atmospheric aerosol over Vermont: chemical composition and

sources. Environ. Sci. Technol. 35: 4604-4621.
Poulton, B. C.; Monda, D. P.; Woodward, D. F.; Wildhaber, M. L.; Brumbaugh, W. G. (1995) Relations between benthic community structure and meta ls concentrations in aquatic macr oinvertebrates: Clark Fork River,

Montana. J. Freshwater Ecol. 10: 277-293.
Prasuna, G.; Zeba, M.; Khan, M. A. (1996) Excre tion of lead as a mechanism for survival on Chrissia halyi (Ferguson, 1969). Bull. Environ. Contam. Toxicol. 57: 849-852.
Prosi, F. (1989) Factors controlling biological availability an d toxic effects of lead in aquatic organisms. Sci. Total

Environ. 79: 157-169. Rabinowitz, M. B. (1993) Modifying soil lead bioavaila bility by phosphate addition. Bull. Environ. Contam.

Toxicol. 51: 438-444. Rabinowitz, M. B. (1995) Stable isotopes of lead for sour ce identification. (Selected proceedings of the 5th world
congress for the World Federation of Associations of Clinical Toxicology Centers and Poison Control
Centers, November 8-11, 1994, Taipei, Taiwan, R.O.C.). J. Toxicol. Clin. ToxicoI. 33: 649-655. Rabinowitz, M. B. (2005) Lead isotopes in soils near five historic American lead smelters and refineries. Sci. Total

Environ. 346: 138-148.
Rabinowitz, M. B.; Wetherill, G. W. (197 2) Identifying sources of lead contamination by stable isotope techniques.

Environ. Sci. Technol. 6: 705-709.
Rabitsch, W. B. (1995a) Metal accumulation in arthropods near a lead/zinc smelter in Ar noldstein, Austria. Environ.

Pollut. 90: 221-237.
Rabitsch, W. B. (1995b) Metal accumula tion in arthropods near a lead/zinc smelter in Arnoldstein, Austria. II.

Formicidae. Environ. Pollut. 90: 249-257.
Rademacher, D. J.; Weber, D. N.; Hillard, C. J. (2005) Waterborne lead exposure affects brain endocannabinoid
content in male but not female fathead minnows ( Pimephales promelas ). Neurotoxicology 26: 9-15.
Radojevic, M.; Harrison, R. M. (1987) Concentrations and pathways of organolead compounds in the environment:

a review. Sci. Total Environ. 59: 157-180. Rahmani, G. N. H.; Sternberg, S. P. K. (1999) Bioremoval of lead from water using Lemna minor . Bioresour.

Technol. 70: 225-230.
Rai, L. C.; Raizada, M. (1989) Effect of bimetallic combin ations of Ni, Cr and Pb on growth, uptake of nitrate

and ammonia, 14CO 2 

# fixation, and nitrogenase activity of Nostoc muscorum . Ecotoxicol. Environ.

Saf. 17: 75-85. Rainbow, P. S. (1996) Heavy metals in aquatic invertebra tes. In: Beyer, W. N.; Hein z, G. H.; Redmon-Norwood,

A. W., eds. Environmental contaminants in wildlife: interpreting tissue concentrations. Boca Raton, FL:
CRC Press; pp. 405-425.

# AX7-230 Rand, G. M.; Wells, P. G.; McCarty, L. S. (1995) In troduction to aquatic toxicology. In: Rand, G. M., ed.
Fundamentals of aquatic toxicity: effects, environmental fate, and risk assessment. 2nd ed. Washington, DC: Taylor & Francis; pp. 3-67.
Rao, J. C. S.; Reddy, T. R. K. (1985) Response of Scenedesmus incrassatulus to lead toxicity in presence of

nutrients. J. Biol. Res. 1: 51-56.

Rao, J. V.; Kavitha, P.; Rao, A. P. (2003) Comparative toxicity of tetra ethyl lead and lead oxide to earthworms,
Eisenia fetida (Savigny). Environ. Res. 92: 271-276.
Reaves, G. A.; Berrow, M. L. (1984) Total lead c oncentrations in Scottish soils. Geoderma 32: 1-8. Redig, P. T.; Lawler, E. M.; Schwartz, S.; Dunnette, J. L.; Stephenson, B.; Duke, G. E. (1991) Effects of chronic
exposure to sublethal concentrations of lead acetate on heme synthesis and imm une function in red-tailed

hawks. Arch. Environ. Contam. Toxicol. 21: 72-77. Reisinger, K.; Stoeppler, M.; Nurnberg, H. W. (1981) Eviden ce for the absence of biologi cal methylation of lead in
the environment. Nature (London) 291: 228-230. Renberg, I.; Brännvall, M.-L.; Bindler, R.; Emteryd, O. (2000) Atmospheric lead pollution history during four
millennia (2000 BC to 2000 AD) in Sweden. Ambio 29: 150-156.
Renberg, I.; Brännvall, M. L.; Bindler, R.; Emteryd, O. (2002) Stable lead isotopes and lake sediments—a useful combination for the study of atmospheric lead pollution history. Sci. Total Environ. 292: 45-54.
Rhea, D. T.; Harper, D. D.; Brumbaugh, W. G.; Farag, A. M. (2004) Biomonitoring in the Boulder River Watershed,

Montana: metal concentrations in biofilm and macroinvertebrates, and relations with macroinvertebrate assemblage. Reston, VA: U.S. Geological Survey; report no. USGS-CERC-91340. Rhue, R. D.; Mansell, R. S.; Ou, L.-T.; Cox, R.; Tang, S. R.; Ouyang, Y. (1992) The fate and behavior of lead alkyls

in the environment: a review. Crit. Rev. Environ. Control 22: 169-193. Rice, T. M.; Blackstone, B. J.; Nixdorf, W. L.; Taylor , D. H. (1999) Exposure to lead induces hypoxia-like
responses in bullfrog larvae ( Rana catesbeiana ). Environ. Toxicol. Chem. 18: 2283-2288.

Richards, B. K.; Steenhuis, T. S.; Peverl y, J. H.; McBride, M. B. (1998) Metal mobility at an old, heavily loaded sludge application site. Environ. Pollut. 99: 365-377.
Richards, B. K.; Steenhuis, T. S.; Peverly, J. H.; McBride, M. B. (2000) Effect of sludge-processing mode, soil
texture, and pH on metal mobility in undisturbed soil columns under accelerated loading. Environ. Pollut.

109: 327-346.

Richards, J. G.; Curtis, P. J.; Burnis on, B. K.; Playle, R. C. (2001) Effects of natural organic matter source on
reducing metal toxicity to rainbow trout ( Oncorhynchus mykiss ) and on metal binding to their gills. Environ.

Toxicol. Chem. 20: 1159-1166.
Rickard, D. T.; Nriagu, J. O. (1978) Aqueous environm ental chemistry of lead. In: Nriagu, J. O., ed. The biogeochemistry of lead in the environment. Part A. Ecological cycles. Amsterdam, The Netherlands:
Elsevier/North-Holland Biomedical Press; pp. 219-284. (Topics in environmental health: v. 1A).
Ritson, P. I.; Bouse, R. M.; Flegal, A. R.; Luoma, S. N. (1999) Stable lead isotopic analyses of historic and contemporary lead contamination of San Francisco Bay estuary. Marine Chem. 64: 71-83.
Rogers, J. T.; Wood, J. G. (2003) Ionoregulatory disruption as the acute toxic mechanism for lead in the rainbow
trout ( Oncorhynchus mykiss ). Aquat. Toxicol. 64: 215-234. Rogers, J. T.; Wood, C. M. (2004) Characterization of bran chial lead-calcium interaction in the freshwater rainbow
trout ( Oncorhynchus mykiss ). J. Exp. Biol. 207: 813-825.
Rosso, A.; Lafont, M.; Exinger, A. (1994) Impact of heavy metals on benthic oligochaete communities in the river

Ill and its tributaries. Water Sci. Technol. 29(3): 241-248.
Roth, M. (1993) Investigations on lead in the soil invertebrates of a forest ecosystem. Pedobiologia 37: 270-279.
Rouff, A. A.; Elzinga, E. J.; Reeder, R. J.; Fisher, N. S. (2005) The infl uence of pH on the kinetics, reversibility and mechanisms of Pb(II) sorption at the calcite-water interface. Geochim. Cosmochim. Acta 69: 5173-5186.
Rouff, A. A.; Elzinga, E. J.; Reeder, R. J. (2006) The effect of aging and pH on Pb (II) sorption processes at the

calcite—water interface. Environ. Sci. Technol. 40: 1792-1798. Ruby, M. V.; Davis, A.; Kempton, J. H.; Drexler, J. W.; Bergstrom, P. D. (1992) Lead bioavailability: dissolution
kinetics under simulated gastric conditions. Environ. Sci. Technol. 26: 1242-1248
Ruby, S. M.; Jaroslawski, P.; Hull, R. (1993) Lead an d cyanide toxicity in sexually maturing rainbow trout,
Oncorhynchus mykiss during spermatogenesis. Aquat. Toxicol. 26: 225-238.
Ruby, M. V.; Davis, A.; Nicholson, A. (1994) In situ formation of lead phosphates in soils as a method to

immobilize lead. Environ. Sci. Technol. 28: 646-654.
Ruparelia, S. G.; Verma, Y.; Mehta, N. S.; Salyed, S. R. (1989) Lead-induced biochemical changes in freshwater

fish Oreochrois mossambicus . Bull. Environ. Contam. Toxicol. 43: 310-314.

# AX7-231 Rusek, J.; Marshall, V. G. (2000) Impact of airborne pollutants on soil fauna. Annu. Rev. Ecol. System. 31:

395-423. Russell, I. J.; Choquette, C. E.; Fang, S. -L.; Dundulis, W. P.; Pao, A. A.; Pszenny, A. A. P. (1981) Forest vegetation
as a sink for atmospheric particulates: quantitative studies in rain and dry deposition. J. Geophys. Res.

C: Oceans Atmos. 86: 5347-5363. Ryan, J. A.; Zhang, P.; Hesterberg, D.; Chou, J.; Sayers , D. E. (2001) Formation of chloropyromorphite in
lead¬contaminated soil amended with hydroxyapa tite. Environ. Sci. Technol. 35: 3798-3803.
Ryan, P. C.; Wall, A. J.; Hilli er, S.; Clark, L. (2002) Insights into sequ ential chemical extraction procedures from quantitative XRD: a study of trace metal partitioning in se diments related to frog malformities. Chem. Geol.

184: 337-357. Rybak, M.; Rybak, I.; Scruton, D. A. (1989) The impact of atmospheric deposition on the aquatic ecosystem with special emphasis on lake productivity, Newfoundland, Canada. Hydrobiologia 179: 1-16.

Sabin, L. D.; Lim, J. H.; Stolzenbach, K. D.; Schiff, K. C. (2005) Contribution of tr ace metals from atmospheric deposition to stormwater runoff in a small impervious urban catchment. Water Res. 39: 3929-3937.
Sadiq, M. (1992) Lead in marine environments. In: Toxic metal chemistry in marine environments, v. 1. New York,
NY: Marcel Dekker, Inc.; pp. 304-355. (Environmental science and pollution control series: v. 1). Sample, B. E.; Beauchamp, J. J.; Efroymson, R. A.; Suter, G. W., II; Ashwood, T. L. (1998) Development and

validation of bioaccumulation models for earthworm s. Oak Ridge, TN: Oak Ridge National Laboratory;

ES/ER/TM-220. Sample, B.; Suter, G. W., II; Beauchamp, J. J.; Efroymson, R. (1999) Literature-d erived bioaccumulation models for
earthworms: development and validation. Environ. Toxicol. Chem. 18: 2110-2120.
Sandifer, R. D.; Hopkin, S. P. (1996) Effects on pH on the toxicity of cadmium, copper, lead and zinc to Folsomia

candida Willem, 1902 (Collembola) in a standard laboratory test system. Chemosphere 33: 2475-2486.
Sansalone, J. J.; Glenn, D. W.; Tribouillard, T. (2003) Phys ical and chemical characteristics of urban snow residuals
generated from traffic activities. Water Air Soil Pollut. 148: 45-60.

Santillan-Medrano, J.; Jurinak, J. J. (1975) The chemistry of lead and cadmium in soil: solid phase formation. Soil

Sci. Soc. Am. Proc. 39: 851-856.
Santos, M. A.; Hall, A. (1990) Influence of inorganic lead on the biochemical blood composition of the eel, Anguilla
anguilla L. Ecotoxicol. Environ. Saf. 20: 7-9.
Sañudo-Peña, M. C.; Romero, J.; Seale, G. E.; Fernandez-Ruiz, J. J.; Walker, J. M. (2000) Activational role of

cannabinoids on movement. Eur. J. Pharmacol. 391: 269-274.

Sauter, S.; Buxton, K. S.; Macek, K. J. ; Petrocelli, S. R. (1976) Effects of exposure to heavy metals on selected
freshwater fish: toxicity of copper, cadmium, chromium , and lead to eggs and fry of seven fish species. Duluth, MN: U.S. Environmental Protection Agency, O ffice of Research and Development; report no. EPA600/3-76-105. Available from: NTIS, Springfield, VA; PB-265612.

Sauvé, S.; McBride, M.; Hendershot, W. (1997) Speciation of lead in contaminated soils. Environ. Pollut.

98: 149-155.

Sauvé, S.; McBride, M.; Hendershot, W. (1998) Soil solution speciation of lead(II): effects of organic matter and
pH. Soil Sci. Soci. Am. J. 62: 618-621. Sauvé, S.; Martinez, C. E.; McBride, M.; Hendershot, W. (2000a) Adsorption of free lead (Pb2+) by pedogenic
oxides, ferrihydrite, and leaf compost. Soil Sci. Soc. Am. J. 64: 595-599.

Sauvé, S.; Hendershot, W.; Allen, H. E. (2000b) Solid-solution partitioning of metals in contaminated soils: dependence on pH, total metal burden, and organic matter. Environ. Sci. Technol. 34: 1125-1131.

Sauvé, S.; Manna, S.; Turmel, M. C.; Roy, A. G.; Courchesne, F. (2003) Solid—solution partitioning of Cd, Cu, Ni,
Pb, and Zn in the organic horizons of a forest soil. Environ. Sci. Technol. 37: 5191-5196.

Saviozzi, A.; Levi-Minzi, R.; Cardelli, R.; Riffaldi, R. (1997) The influence of heavy metals on carbon dioxide
evolution from a typic xerochrept soil. Water Air Soil Pollut. 93: 409-417.
Sayer, M. D. J.; Reader, J. P.; Morris, R. (1989) The effect of calcium concentr ation on the toxicity of copper, lead and zinc to yolk-sac fry of brown trout, Salmo trutta L., in soft, acid water. J. Fish Biol. 35: 323-332.
Scally, S.; Davison, W.; Zhang, H. (2003) In situ meas urements of dissociation kinetics and labilities of metal
complexes in solution using DGT. Environ. Sci. Technol. 37: 1379-1384.
Schaule, B. K.; Patterson, C. C. (1 981) Lead concentrations in the northeast Pacifi c: evidence for global
anthropogenic perturbations. Earth Planet. Sci. Lett. 54: 97-116. Scheckel, K.G.; Impellitteri, C.A.; Ryan, J.A.; McEvoy, T. (2003) Assessment of sequential extraction procedure for
perturbed lead-contaminated samples with and without phosphorus amendments. Environ. Sci. Technol.

37: 1892-1898.

# AX7-232 Scherer, E.; McNicol, R. E. (1998) Preferen ce-avoidance responses of lake whitefish ( Coregonus clupeaformis ) to competing gradients of light and copper, lead, and zinc. Water Res. 32: 924-929. Scheuhammer, A. M. (1987) The chronic toxicity of aluminum, cadmium, mercury and lead in birds: a review.

Environ. Pollut. 46: 263-295.
Scheuhammer, A. M. (1989) Monitoring wild bird populations for lead exposure. J. Wildl. Manage. 53: 759-765.
Scheuhammer, A. M. (1991) Effects of aci dification on the availability of toxic metals and calcium to wild birds and

mammals. Environ. Pollut. 71: 329-375.
Schlesinger, W. H. (1997) Biogeochemis try: an analysis of global change. 2n d ed. San Diego, CA: Academic Press. Schlick, E.; Mengel, K.; Friedberg, K. D. (1983) The e ffect of low lead doses in vitro and in vivo on the d -ala- d
activity of erythrocytes, bone marrow cells, liver and brain of the mouse. Arch. Toxicol. 53: 193-205.
Schmitt, C. J.; Brumbaugh, W. G. (1990) National contaminant biomonitoring program: concentrations of arsenic, cadmium, copper, lead, mercury, selenium, and zinc in U.S. freshwater fish, 1976–1984. Arch. Environ.

Contam. Toxicol. 19: 731-747. Schubauer-Berigan, M. K.; Dierkes, J. R.; Monson, P. D.; Ankley, G. T. (1993) pH-dependent toxicity of Cd, Cu,

Ni, Pb and Zn to Ceriodaphnia dubia, Pimephales promelas, Hyalella azteca and Lumbriculus variegatus

. Environ. Toxicol. Chem. 12: 1261-1266. Schwartz, M. L.; Curtis, P. J.; Playle, R. C. (2004) Influence of natural organic matter source on acute copper, lead,
and cadmium toxicity to rainbow trout ( Oncorhynchus mykiss ). Environ. Toxicol. Chem. 12: 2889-2899.
Scudlark, J.; Church, T.; Conko, K.; Ondov, J.; Han, M. (1994) The wet depo sition of trace elements on Delmarva and their utility as emission source indicators. Annapo lis, MD: Maryland Department of Natural Resources,
Chesapeake Bay Research and Monitoring Program; report no. CBRM-AD-94-3. Available from: NTIS,
Springfield, VA; PB94-178373. Available: http ://esm.versar.com/pprp/bibliography/CBRM-AD-94- 3/CBRM-AD-94-3.pdf [24 August, 2006].

Scudlark, J. R.; Rice, K. C.; Conko, K. M.; Bricker, O. P. ; Church, T. M. (2005) Transmission of atmospherically
drived trace elements through an un developed, forested Maryland wate rshed. Water Air Soil Pollut. 163:

53-79. Seiler, J. R.; Paganelli, D. J. (1987) Ph otosynthesis and growth response of red spruce and loblolly pine to soilapplied lead and simulated acid rain. For. Sci. 33: 668-675.
Semlali, R. M.; Van Oort, F.; Denaix, L.; Loubet, M. ( 2001) Estimating distributions of endogenous and exogenous
Pb in soils by using Pb isotopic ratios. Environ. Sci. Technol. 35: 4180-4188.
Senwo, Z. N.; Tabatabai, M. A. (1999) Aspartase activity in soils: effects of trace elements and relationships to other amidohydrolases. Soil Biol. Biochem. 31: 213-219.

Shaffer, R. E.; Cross, J. O.; Rose-Pehrsson, S. L.; El am, W. T. (2001) Speciation of chromium in simulated soil samples using x-ray absorption spectroscopy and multivar iate calibration. Anal. Chim. Acta 442: 295-304.
Sharma, N.; Gardea-Torresday, J. L.; Parson, J.; Sahi, S. V. (2004) Chemical speciation and cellular deposition of

lead in Sesbania drummondii . Environ. Toxicol. Chem. 23: 2068-2073.

Shirahata, H.; Elias, R. W.; Patterson , C. C.; Koide, M. (1980) Chronological variations in concentrations and
isotopic compositions of anthropogenic atmospheric lead in sediments of a remote subalpine pond.

Geochim. Cosmochim. Acta 44: 149-162. Shugart, L. R. (1995) Environmental genotoxicology. In: Rand, G. M., ed. Fundamentals of aquatic toxicology:
effects, environmental fate and risk assessment. 2nd ed. Washington, DC: Taylor and Francis; pp. 405-419.
Shuman, L. M. (1982) Separating soil iron-oxide and mang anese-oxide fractions for mi cro-element analysis. Soil

Sci. Soc. Am. J. 46: 1099-1102.
Siccama, T. G. (1974) Vegetation, soil, and climate on Green Mountains of Vermont. Ecol. Monogr. 44: 325-349.
Sieghardt, H. (1990) Heavy-metal uptake and distribution in Silene vulgaris and Minuartia verna growing on mining-dump material containing lead and zinc. Plant Soil 123: 107-111.
Sigg, L.; Black, F.; Buffle, J.; Cao, J.; Cleven, R.; Daviso n, W.; Galceran, J.; Gunkel, P.; Kalis, E.; Kistler, D.;
Martin, M.; Noel, S.; Nur, Y.; Odzak, N.; Puy, J.; Van Riemsdijk, W.; Temminghoff, E.; Tercier-Waeber, M. L.; Toepperwien, S.; Town, R. M. ; Unsworth, E.; Warnken, K. W.; We ng, L.; Xue, H.; Zhang, H. (2006)
Comparison of analytical techniques for dynamic trace metal speciation in natural freshwaters. Environ. Sci.

Technol. 40: 1934-1941.
Simòes Gonçalves, M. L. S.; Vilhena, M. F. C.; Fernan des Sollis, J. M.; Castro Romero, J. M.; Sampayo, M. A.
(1991) Uptake of lead and its influence in the alga Sel enastrum capricornutum Printz. Talanta 38: 1111-

1118. Simonetti, A.; Gariepy, C.; Carignan, J. (2000) Pb and Sr isotopic evidence for sources of atmospheric heavy metals
and their deposition budgets in northeastern North America. Geochim. Cosmochim. Acta 64: 3439-3452.

# AX7-233 Small, W. D. (1973) Isotopic compositions of selected ore leads from northwestern Washington. Can. J. Earth Sci.

10: 670-674. Smith, E.; Naidu, R.; Alston, A. M. (2002) Chemistry of in organic arsenic in soils. II. Effect of phosphorus, sodium,
and calcium on arsenic absorption. J. Environ. Qual. 31: 557-563.
Snoeijs, T.; Dauwe, T.; Pinxten, R.; Darras, V. M.; Arckens, L.; Eens, M. (2005) The combined effect of lead exposure and high or low dietary calcium on health and immunocompetence in the zebra finch ( Taeniopygia

guttata ). Environ. Pollut. 134: 123-132.
Sopper, W. E. (1989) Revegetation of a contaminated zinc smelter site. Landscape Urban Plann. 17: 241-250. Sopper, W. E. (1993) Municipal sludge use in land reclamation. Boca Raton, FL: Lewis Publishers.
Spehar, R. L.; Fiandt, J. T. (1986) Acute and chronic effects of water quality criteria-based metal mixtures on
aquatic species. Environ. Toxicol. Chem. 5: 917-931. Spehar, R. L.; Anderson, R. L.; Fiandt, J. T. (1978) Toxicity and bioaccumulation of cadmium and lead in aquatic

invertebrates. Environ. Pollut. 15: 195-208. Sposito, G.; Coves, J. (1988) SOILCHEM: A computer program for the calculation of chemical speciation in soils.
Berkeley, CA: University of California, Kerney Foundation of Soil Science.
Sposito, G.; Lund, L. J.; Chang, A. C. (1982) Trace metal chemis try in arid-zone field soils amended with sewage sludge. 1. Fractionation of Ni, Cu, Zn, Cd, and Pb in solid-phases. Soil Sci. Soc. Am. J. 46: 260-264.
Spry, D. J.; Wiener, J. G. (1991) Metal bioavailability and t oxicity to fish in low-alkalinity lakes: a critical review.

Environ. Pollut. 71: 243-304. Spurgeon, D. J.; Hopkin, S. P. (1996a) The effects of metal contamination on earthworm populations around a
smelting works: quantifying species effects. Appl. Soil Ecol. 4: 147-160.
Spurgeon, D. J.; Hopkin, S. P. (1996b) Risk assessment of the threat of secondary poisoning by metals to predators of earthworms in the vicinity of a primary smelting works. Sci. Total Environ. 187: 167-183.
Squire, S.; Scelfo, G. M.; Revenaugh, J.; Flegal, A. R. (2002) Decadal trends of silver and lead contamination in San
Francisco Bay surface waters. Enviro n. Sci. Technol . 36: 2379-2386. Stacey, J. S.; Zartman, R. E.; NKomo, I. T. (1968) A lead isotope study of galena and selected feldspars from
mining districts in Utah. Econ. Geol. Bull. Soc. Econ. Geol. 63: 796-814.
Steding, D. J.; Dunlap, C. E.; Flegal, A. R. (2000) New isotopic evidence for chronic l ead contamination in the San Francisco Bay estuary system: implica tions for the persistence of past industrial lead emissions in the
biosphere. Proc. Natl. Acad. Sci. U. S. A. 97: 11181-11186.

Steele, C. W.; Strickler-Shaw, S. ; Taylor, D. H. (1989) Behavior of tadpoles of the bullfrog, Rana catesbeiana , in response to sublethal lead exposure. Aquat. Toxicol. 14: 331-344.

Steele, C. W.; Strickler-Shaw, S.; Taylor, D. H. (1991) Failure of Bufo americanus tadpoles to avoid lead-enriched water. J. Herpetol. 25: 241-243.
Steinnes, E.; Friedland, A. J. (2005) Lead migration in podzolic soils from Scandanavia and the United States of

America. Can. J. Soil Sci. 85: 291-294. Stephan, C. E.; Mount, D. I.; Hansen, D. J.; Gentile, J. H. ; Chapman, G. A. (1985) Guidelines for deriving numerical
national water quality criteria for the protection of aqua tic organisms and their uses. Washington, D.C.: U.S.
Environmental Protection Agency; report no. EPA/822 -R85-100. Available from: NTIS, Springfield, VA;

PB85-227049.

Storm, G. L.; Fosmire, G. J.; Bellis, E. D. (1994) Persistence of metals in soil and selected vertebrates in the vicinity
of the Palmerton zinc smelters. J. Environ. Qual. 23: 508-514. Stouthart, A. J. H. X.; Spanings, F. A. T.; Lock, R. A. C.; Wendelaar Bonga, S. E. (1994) Effects of low water pH
on lead toxicity to early lif e stages of the common carp ( Cyprinus carpio ). Aquat. Toxicol. 30: 137-151.
Strawn, D. G.; Sparks, D. L. (1999) The use of XAFS to distinguish between inner- and outer-sphere lead adsorption complexes on montmorillonite. J. Co lloid Interface Sci. 216: 257-269.
Strawn, D. G.; Sparks, D. L. (2000) Effects of soil organic matter on the kinetics and mechanisms of Pb(II) sorption
and desorption in soil. Soil Sci. Soc. Am. J. 64: 144-156. Stripp, R. A.; Heit, M.; Bogen, D. C.; Bidanset, J.; Tr ombetta, L. (1990) Trace elemen t accumulation in the tissues
of fish from lakes with different pH values. Water Air Soil Pollut. 51: 75-87.
Stumm, W.; Morgan, J. J. (1970) Aquatic chemistry: an introduction emphasizing chemical equilibria in natural

waters. New York, NY: Wiley-Interscience.
Stumm, W.; Morgan, J. J. (1995) Aquatic chemistry: chemical equilibria and rates in natural waters. 3rd ed. New York, NY: Wiley Interscience. [Schnoor, J. L. ; Zehnder, A., eds. Environmental science and
technology series].

# AX7-234 Sturges, W. T.; Barrie, L. A. (1987) Lead 206/207 isotope ratios in the atmo sphere of North America as tracers of
US and Canadian emissions. Nature (London) 329: 144-146. Sturges, W. T.; Hopper, J. F.; Barrie, L. A.; Schnell, R. C. (1993) Stable lead isotope ratios in Alaskan Arctic

aerosols. Atmos. Environ. 27A: 2865-2871.
Sulkowski, M.; Hirner, A. V. (2006) Element fractionation by sequential extraction in a soil with high carbonate content. Appl. Geochem. 21: 16-28.

Svecevi č ius, G. (1991) The role of olfaction in avoidance reactions to pollutants by vimba Vimba vimba (L.). Ekologija 4: 3-8.

Svecevi č ius, G. (2001) Avoidance response of rainbow trout Oncorhynchus mykiss to heavy metal model mixtures:
a comparison with acute toxicity tests. Bu ll. Environ. Contam. Toxicol. 67: 680-687.
Swansburg, E. O.; Fairchild, W. L.; Fryer, B. J.; Ciborowski, J. J. H. (2002) Mouthpart deformities and community composition of chironomidae (Diptera) larvae sownstream of metal mines in New Brunswick, Canada.

Environ. Toxicol. Chem. 21: 2675-2684. Swanson, K. A.; Johnson, A. H. (1980) Trace metal budgets for a forested watershed in the New Jersey Pine

Barrens. Water Resour. Res. 16: 373-376. Syracuse Research Corporation (SRC). (1999) The environmental fate of lead and lead compounds. Washington, DC: U.S. Environmental Protection Agency; contract no. SRC 68-D5-0012.

Szarek- Ł ukaszewska, G.; S ł ysz, A.; Wierzbicka, M. (2004) Response of Armeria maritima (Mill.) Willd. to Cd, Zn,

and Pb. Acta Biol. Cracoviensia Ser. Bot. 46: 19-24. Szulczewski, M. D.; Helmke, P. A.; Bleam, W. F. (1997) Comparison of XANES analyses and extractions to
determine chromium speciation in contaminated soils. Environ. Sci. Technol. 31: 2954-2959.
Tada, F.; Suzuki, S. (1982) Adsorption and desorption of heavy metals in bottom mud of urban rivers. Water Res.

16: 1489-1494. Tao, S. Li, H.; Liu, C.; Lam, K. C. (2000) Fish uptake of inorganic and mucus complexes of lead. Ecotoxicol.

Environ. Saf. 46: 174-180. Tejedor, M. C.; Gonzalez, M. (1992) Comparison between lead levels in blood and bone tissue of rock doves
(Columba livia) treated with lead acetate or expose d to the environment of Alcala-de-Henares. Bull.

Environ. Contam. Toxicol. 48: 835-842. Templeton, A. S.; Spormann, A. M.; Brown, G. E. (2003a) Speciation of Pb(II) sorbed by Burkholderia

cepacia /goethite composites. Environ. Sci. Technol. 37: 2166-2172.
Templeton, A. S.; Trainor, T. P.; Spor mann, A. M.; Newville, M.; Sutton, S. R.; Dohnalkova, A.; Gorby, Y.; Brown, G. E. (2003b) Sorption versus biom ineralization of Pb(II) within Burkholderia cepacia biofilms. Environ.

Sci. Technol. 37: 300-307. Terhivuo, J.; Pankakoski, E.; Hyvärinen, H.; Koivisto, I. (1994) Pb uptake by ecologically dissimilar earthworm
(Lumbricidae) species near a lead smelter in south Finland. Environ. Pollut. 85: 87-96.
Tessier, A.; Campbell, P. G. C. (1987) Partitioning of tr ace-metals in sediments: relationships with bioavailability. Hydrobiologia 149: 43-52.
Tessier, A.; Campbell, P. G. C. (1988) Part itioning of trace metals in sediments. In: Kramer, J. R.; Allen, H. E., eds.
Metal speciation: theory, analysis and application. Chelsea, MI : Lewis Publishers, pp. 183-199. Tessier, A.; Campbell, P. G. C.; Bisson, M. (1979) Sequen tial extraction procedure for the speciation of particulate

trace-metals. Anal. Chem. 51: 844-851.

Timmermans, K. R.; Peeters, W.; Tonkes, M. (1992) Cadmium, zinc, lead and copper in Chironomus riparius (Meigen) larvae (Diptera, Chironomidae): uptake and effects. Hydrobiologia 241: 119-134.
Tipping, E. (1994) WHAM—A chemical equilibrium model and computer code for waters, sediments, and soils
incorporating a discrete site/electrostatic model of ion-binding by humic substances. Comput. Geosci. 20:

973-1023. Tipping, E.; Woof, C. (1990) Humic substances in acid or ganic soils: modelling their release to the soil solution in
terms of humic charge. J. Soil Sci. 41: 573-586. Tipping, E.; Rieuwerts, J.; Pan, G.; Ashmore, M. R.; Lofts, S.; Hill, M. T. R.; Farago, M. E.; Thornton, I. (2003)
The solid-solution partitioning of heavy metals (Cu, Zn, Cd, Pb) in upland soils of England and Wales.

Environ. Pollut. 125: 213-225. Tolonen, K.; Jaakkola, T. (1983) History of lake acidification and air pollution studied on sediments in south

Fin land. Ann. Bot. Fenn. 20: 57-78.
Townsend, A. T.; Yu, Z.; McGoldrick, P.; Hutton, J. A. ( 1998) Precise lead isotope ratios in Australian galena
samples by high resolution inductively coupled plasma mass spectrometry. J. Anal. At. Spectrom. 13: 809-

813.

# AX7-235 Trivedi, P.; Dyer, J. A.; Sparks, D. L. (2003) Lead sorption onto ferrihydrite. 1. A macroscopic and spectroscopic

assessment. Environ. Sci. Technol. 37: 908-914. Turner, R. S.; Johnson, A. H.; Wang, D. (1985) Biogeochemistry of lead in McDonalds Branch Watershed, New
Jersey Pine Barrens. J. Environ. Qual. 14: 305-314.
Tyler, G. (1981) Leaching of metals from the A -horizon of a spruce forest soil. Water Air Soil Pollut. 15: 353-369. Tyler, G.; Balsberg Påhlsson, A.-M.; Bengtsson, G.; Bååth, E.; Tranvik, L. (1989) Heavy-metal ecology of
terrestrial plants, microorganisms and invert ebrates. Water Air Soil Pollut. 47: 189-215.
U.S. Environmental Protection Agency. (1979) Water-related environmental fate of 129 priority pollutants. Volume I: Introduction and technical background, metals and inorganics, pesticides and PCBs. Washington, DC:
Office of Water Planning and Standards; report no. EPA-440/4-79-029a. Available from: NTIS, Springfield,

VA; PB80-204373. U.S. Environmental Protection Agency. (1985) Ambient water quality criteria for lead - 1984. Washington, DC:
Office of Water Regulations and Standards, Criteria and Standards Division; report no. EPA/440/5-84/027. Available: http://www.epa.gov/npdes/pubs/owm586.pdf [26 October, 2005].
U.S. Environmental Protection Agency. (1986a) Air quality criteria for lead. Research Tr iangle Park, NC: Office of

Health and Environmental Assessment, Environmental Criteria and Assessment Office; EPA report no. EPA-600/8-83/028aF-dF. 4v. Available from: NTIS, Springfield, VA; PB87-142378.
U.S. Environmental Protection Agency. (1986b) Test methods for evaluating solid waste. Volumes lA through lC:
laboratory manual physical/chemical methods. Volume ll: field manual physical/chemical methods. Washington, DC: Office of Solid Waste and Emergency Response; report no. SW 846. Available from:
NTIS, Springfield, VA; PB88-239223.
U.S. Environmental Protection Agency. (1986c) Quality cr iteria for water 1986. Washington, DC: Office of Water Regulations and Standards; EPA report no. EPA/440/5-86/001. Available from: NTIS, Springfield, VA;

PB87-226759. U.S. Environmental Protection Agency. (1990) Review of the national ambient air quality standards for lead:

assessment of scientific and technical information: OAQPS staff paper. Research Triangle Park, NC: Office
of Air Quality Planning and Standards; report no. EPA-450/2-89/022. Available from: NTIS, Springfield,

VA; PB91-206185. U.S. Environmental Protection Agency. (1991) Methods for the determination of metals in environmental samples.
Washington, DC: U.S. Environmental Protection Agency; EPA/600/4-91-010.
U.S. Environmental Protection Agency. (1999) Unde rstanding variation in partition coefficient, K d 

# , values. Volume II: review of geoc hemistry ad available K d 

# values for cadmium, cesium, chromium, lead,
plutonium, radon, strontium, thorium, tritium (3H), and uranium. Washington, DC: Office of Air and Radiation; report no. EPA 402-R-99-004B. Available:
http://www.epa.gov/radiation/docs/kdreport/vol2/ 402-r-99-004b.pdf [26 October, 2005].
U.S. Environmental Protection Agency. (2001) Test methods for evaluating solid waste, physical/chemical methods (SW-846 integrated manual with updates through fina l update III). Washington, DC: Office of Solid Waste
and Emergency Response; report no. SW 846. Available from: NTIS, Springfield, VA; PB97-156111.
Available: http://www.epa.gov/epaoswer/hazwaste/test/sw846.htm [1 November, 2005]. U.S. Environmental Protection Agency. (2002) Site technology capsule: demonstration of Rocky Mountain
remediation services soil amendment process. Cincinnati, OH: National Risk Management Research
Laboratory; EPA/540/R-02/501A. Available: http://www.epa.gov/ORD/NRMRL/pubs/540r02501/ 540R02501A.pdf [28 September, 2005].
U.S. Environmental Protection Agency. (2003) Draft strategy: proposed revisions to the "Guidelines for deriving
numerical national water quality criteria for the protecti on of aquatic organisms and their uses" [Draft copy]. Available: http://www.epa.gov/waterscience/criteria/aqlife.html#guide [6 April, 2006].
U.S. Environmental Protection Agency. (2004a) Estimation of relative bioavailability of lead in soil and soil-like
materials using in vivo and in vitro methods. Washington, DC: Office of Solid Waste and Emergency
Response; report no. OSWER 9285.7-77. U.S. Environmental Protection Agency. (2004b) Framework for inorganic metals risk assessment [external review
draft]. Washington, DC: Risk Assessment Forum; report no. EPA/630/P-04/068B. Available: http://cfpub2.epa.gov/ncea/raf/recordisplay.cfm?deid=8 8903 [26 October, 2005].
U.S. Environmental Protection Agency. (2005a) Guidance for developing ecological soil screening levels (Eco-SSLs). Washington, DC: Office of Solid Waste and Emergency Response, OSWER
directive 9285.7-55, November 2003-revised February 2005. Available:
http://www.epa.gov/superfund/programs/risk/eco risk/ecossl.pdf [29 September, 2005].

# AX7-236 U.S. Environmental Protection Agency. (2005b) Ecological so il screening levels for lead. Interim final. Washington,
DC: Office of Solid Waste and Emergency Response, OSWER directive 9285.7-70. U.S. Environmental Protection Agency. (2005c) Procedures for the derivation of equilibrium partitioning sediment
benchmarks (ESBs) for the protection of benthic organisms: metal mixtures (cadmium, copper, lead, nickel,
silver and zinc). Washington, DC: Office of Research and Development; EPA-600-R-02-011. Unruh, D. M.; Fey, D. L.; Church, S. E. (2000) Chemical data and lead isotopic compositions of geochemical
baseline samples from streambed sediments and smelter slag, lead isotopic compositions in fluvial tailings,
and dendrochronology results from the Boulder River watershed, Jefferson County, Montana. Denver, CO: U.S. Department of the Interior, U.S. Geological Survey. USGS open file report 00-0038. Available:
http://pubs.usgs.gov/of/2000/ofr-00-0038/OFR-00-038.pdf [5 April, 2006].
Utsunomiya, S.; Jensen, K. A.; Keeler, G. J.; Ewing, R. C. (2004) Direct iden tification of trace metals in fine and ultrafine particles in the Detroit urban atmos phere. Environ. Sci. Technol. 38: 2289-2297.
Van Den Berg, G. A.; Gustav Loch, J. P.; Van Der Heidjt, L. M.; Zwolsman, J. J. G. (1998) Vertical distribution of acid-volatile sulfide and simultaneously extracted metals in a recent sedimentation area of the River Meuse

in The Netherlands. Environ. Toxicol. Chem. 17: 758-763.
Van Hattum, B.; Van Straalen, N. M.; Govers, H. A. J. ( 1996) Trace metals in populations of freshwater isopods:

influence of biotic and abiotic variables. Arch. Environ. Contam. Toxicol. 31: 303-318.

Vantelon, D.; Lanzirotti, A.; Scheinost, A. C.; Kretzschmar, R. (2005) Spa tial distribution and speciation of lead
around corroding bullets in a shooting range soil studied by micro-X-ray fluorescence and absorption spectroscopy. Environ. Sci. Technol. 39: 4808-4815.
Varanasi, U.; Gmur, D. J. (1978) Influence of water-borne and dietary calcium on uptake and retention of lead by
coho salmon ( Oncorhynchus kisutch ). Toxicol. Appl. Pharmacol. 46: 65-75. Vásquez, M. D.; López, J.; Carballeir a, A. (1999) Uptake of heavy metals to the extracellular and intracellular
compartments in three species of aquatic bryophyte. Ecotoxicol. Environ. Saf. 44: 12-24.
Verma, S.; Dubey, R. S. (2003) Lead toxicity induces lipid peroxidation and alters the activities of antioxidant enzymes in growing rice plants. Plant Sci. 164: 645-655.
Verma, N.; Singh, M. (2005) Biosensors for heavy metals. Biometals 18: 121-129.
Véron, A. J.; Church, T. M.; Flegal, A. R. (1998) Lead isotopes in the west ern North Atlantic: transient tracers of pollutant lead inputs. Environ. Res. 78: 104-111.
Verslycke, T.; Vangheluwe, M. ; Heijerick, D.; De Schamphelaere, K.; Va n Sprang, P.; Janssen, C. R. (2003) The
toxicity of metal mixtures to the estuarine mysid Neomysis integer (Crustacea: mysidacea) under changing salinity. Aquat. Toxicol. 64: 307-315.
Vink, J. P. M. (2002) Measurement of heavy metal speciation over redox gradients in natural water—sediment interfaces and implications for uptake by benthic organisms. Environ. Sci. Technol. 36 : 5130-5138. Vinogradoff, S. I.; Graham, M. C.; Thor nton, G. J. P.; Dunn, S. M.; Bacon, J. R.; Farmer, J. G. (2005) Investigation
of the concentration and isotopic composition of inputs and outputs of Pb in waters at an upland catchment

in NE Scotland. J. Environ. Monit. 7: 431-444.
Vogiatzis, A. K.; Loumbourdis, N. S. (1999) Exposure of Rana ridibunda to lead I. Study of lead accumulation in
various tissues and hepatic δ -aminolevulinic acid dehydratase activity. J. Appl. Toxicol. 19: 25-29. Vogt, G.; Quinitio, E. T. (1994) Accumulation an d excretion of metal granules in the prawn, Penaeus monodon

, exposed to water-borne copper, lead, iron and calcium. Aquat. Toxicol. 28: 223-241.
Wang, E. X.; Benoit, G. (1996) Mechanisms controlling the mobility of lead in the spodosols of a northern hardwood forest ecosystem. Environ. Sci. Technol. 30: 2211-2219.
Wang, E. X.; Benoit, G. (1997) Fate and transport of contaminant lead in spodosols: a simple box model analysis.

Water Air Soil Pollut. 95: 381-397. Wang, E. X.; Bormann, F. H.; Benoit, G. (1995) Evidence of complete retention of atmospheric lead in the soils of
northern hardwood forested ecosystems. Environ. Sci. Technol. 29: 735-739.
Ward, T. J.; Hutchings, P. A. (1996) Effects of trace metals on infaunal species com position in polluted intertidal and subtidal marine sediments near a lead smelter, Spencer Gulf, South Australia. Mar. Ecol. Prog. Ser.

135: 123-135. Ward, T. J.; Young, P. C. ( 1982) Effects of sediment trace metals and pa rticle size on the community structure of epibenthic seagrass fauna near a lead smelter, South Australia. Mar. Ecol. Prog. Ser. (Oldendorf) 9: 137-

146.
Waters, T. F. (1995) Sediment in streams: sources, biol ogical effects, and contro l. Bethesda, MD: American
Fisheries Society. (American Fi sheries Society monograph 7).

# AX7-237 Watmough, S. A.; Hutchinson, T. C. (2004) The quantification and distribution of pollution Pb at a woodland in

rural south central Ontario, Canada. Environ. Pollut. 128: 419-428. Watmough, S. A.; Hutchinson, T. C.; Sager, E. P. S. (1998) Changes in tree ring chemistry in sugar maple ( Acer

saccharum ) along an urban-rural gradient in southern Ontario. Environ. Pollut. 101: 381-390.
Watmough, S. A.; Hutchinson, T. C.; Dillo n, P. J. (2004) Lead dynamics in the forest floor and mineral soil in south-central Ontario. Biogeochemistry 71: 43-68.
Weber, D. N. (1993) Exposure to sublethal levels of waterb orne lead alters reproductive behavior patterns in fathead
minnows ( Pimephales promelas ). Neurotoxicology 14: 347-358.
Weber, D. N. (1996) Lead-induced metabolic imbalances and feeding alterations in juvenile fathead minnows
( Pimephales promelas ). Environ. Toxicol. Water Qual. 11: 45-51.
Wehrli, B.; Dinkel, C.; Müller, B. (1994) Measurement of benthic gradients in deep lakes with ion selective electrodes and video endoscopy. Mineral. Mag. 58A: 961-962.
Weis, J. S.; Weis, P. (1998) Effects of exposure to lead on behavior of mummichog ( Fundulus heteroclitus L.) larvae. J. Exp. Mar. Biol. Ecol. 222: 1-10.
Welter, E.; Calmano, W.; Mangold, S.; Tröger, L. (1999) Chemical speciation of heavy metals in soils by use of
XAFS spectroscopy and electron microscopical techni ques. Fresenius J. Anal. Chem. 364: 238-244. Weng, L.; Temminghoff, E. J. M.; Lofts, S.; Tipping, E.; Van Riemsdijk, W. (2002) Complexation with dissolved
organic matter and solubility control of heavy metals in a sandy soil. Environ. Sci. Technol. 36: 4804-4810.
Wierzbicka, M. (1999) Comparison of lead tolerance in Allium cepa with other plant species. Environ. Pollut.

104: 41-52. Wilczek, G.; Babczynska, A.; Augustyniak, M.; Migula, P. (2004) Relations between me tals (Zn, Pb, Cd and Cu)
and glutathione-dependent detoxifying enzymes in spiders from a heavy metal pollution gradient. Environ.

Pollut. 132: 453-454.
Wilke, B.-M. (1989) Long-term effects of different inorganic pollutants on nitrogen transformations in a sandy

cambisol. Biol. Fertil. Soils 7: 254-258.

Wilson, A. R.; Lion, L. W.; Nelson, Y. M.; Shuler, M. L.; Ghiorse, W. C. (2001) The effects of pH and surface
composition on Pb adsorption to natural freshwater biofilms. Environ. Sci. Technol. 35: 3182-3189.

Winner, R. W.; Boesel, B. W.; Farrell, M. P. (1980) Insect community st ructure as an index of heavy-metal pollution in lotic ecosystems. Can. J. Fish. Aquatic Sci. 37: 647-655.
Woodward, D. F.; Brumbaugh, W. G.; DeL onay, A. J.; Little, E. E.; Smith, C. E. (1994) Effects on rainbow trout fry

of a metals-contaminated diet of benthic invertebrates from the Clark Fork River, Montana. Trans. Am.

Fish. Soc. 123: 51-62.
Woodward, D. F.; Hansen, J. A.; Bergman, H. L.; Little, E. E.; DeLonay, A. J. (1995) Brown trout avoidance of

metals in water characteristic of the Clark Fork River, Montana. Can. J. Fish. Aquat. Sci. 52: 2031-2037.
Wu, Z. Y.; Han, M.; Lin, Z. C.; Ondov, J. M. (1994) Chesapeake Bay Atmospheric Deposition study, Year 1:
sources and dry deposition of selected elements in aerosol particles. Atmos. Environ. 28: 1471-1486. Xia, K.; Bleam, W.; Helmke, P. A. (1997) Studies of the nature of Cu2+ and Pb2+ binding sites in soil humic
substances using X-ray absorption spectroscopy. Geochim. Cosmochim. Acta 61: 2211-2221.
Yanai, R. D.; Ray, D. G.; Siccama, T. G. (2004) Lead reduction and redistribution in the forest floor in New Hampshire northern hardwoods. J. Environ. Qual. 33: 141-148.
Yang, H.; Rose, N. (200 5) Trace element pollution records in some UK lake sediments, their history, influence
factors and regional differences. Environ. Int. 31: 63-75. Yang, Y.-Y.; Jung, J.-Y.; Song, W.-Y.; Suh, H.-S.; Lee, Y. (2000) Identification of rice varieties with high tolerance
or sensitivity to lead and characterization of the mech anism of tolerance. Plant Physiol. 124: 1019-1026.
Yang, J.; Mosby, D. E.; Casteel, S. W.; Blanchar, R. W. (2001) Lead im mobilization using phosphoric acid in a

smelter-contaminated urban soil. Environ. Sci. Technol. 35: 3553-3559.
Yap, C. K.; Tan, S. G.; Ismail, A.; Omar, H. (2004) A llozyme polymorphism and heavy metal levels in the greenlipped mussel Perna viridis (Linnaeus) collected from contaminated and uncontaminated sites in Malaysia.

Environ. Int. 30: 39-46.
Yi, S. -M.; Shahin, U.; Sivadechathep, J.; Sofuoglu, S. C.; Holsen, T. M. (2001) Ov erall elemental dry deposition
velocities measured around Lake Michigan. Atmos. Environ. 35: 1133-1140. Young, T. F.; Sanzone, S., eds. (2002) A framework for assessing and reporting on ecological condition: an SAB
report. Washington, DC: U.S. Environmental Protection Agency, Science Advisory Board; report no. EPASAB-EPEC-02-009. Available: h ttp://www.epa.gov/sab/ pdf/epec02009.pdf [9 December, 2003].
Zartman, R. (1974) Lead isotopic provinces in the Co rd illera of the western United States and their geologic
significance. Econ. Geol. 69: 792-805.

# AX7-238 Zenk, M. H. (1996) Heavy metal detoxification in higher plants—a review. Gene 179: 21-30.
Zhang, Y.-H. (2003) 100 years of Pb deposition and transpor t in soils in Champaign, Illinois, U.S.A. Water Air Soil

Pollut. 146: 197-210.
Zhang, H.; Davidson, W.; Miller, S.; Tych, W. (1995) In situ high resolution measurements of fluxes of Ni, Cu,
Fe and Mn and concentrations of Zn and Cd in pore waters by DOT. Geochim. Cosmochim. Acta

59: 4181-4192. Zhu, Y. G.; Chen, S. B.; Yang, J. C. (2004) Effects of soil amendments on lead uptake by two vegetable crops from

a lead-contaminated soil from Anhui, China. Environ. Int. 30: 351-356. Zimdahl, R. L.; Skogerboe, R. K. (1977) Behavior of lead in soil. Environ. Sci. Technol. 11: 1202-1207.

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