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Summary Minutes of the

U.S. Environmental Protection Agency (EPA)

Clean Air Scientific Advisory Committee (CASAC)

Lead Review Panel

Public Meeting

July 20 - 21, 2011

Date and Time: Wednesday, July 20, 2011, 9:00 AM – 5:30 PM ET; Thursday, July 21, 2011,

8:30 AM – 12:30 PM ET

Location: Marriott at Research Triangle Park, 4700 Guardian Drive, Durham, NC, 27703

Purpose: The purpose of the meeting was to conduct a peer review of EPA’s Integrated 

Science Assessment for Lead (First External Draft - May 2011) and a 

consultation on EPA’s Review of the National Ambient Air Quality Standards 

for Lead: Risk and Exposure Assessment Planning Document (June 2011).

Participants: CASAC Lead Panel (for full roster, see Attachment A)

Dr. H. Christopher Frey, Chair

Mr. George Allen

Dr. Herbert Allen

Dr. Deborah Cory-Slechta

Dr. Cliff Davidson

Dr. Philip Goodrum

Dr. Sean Hays

Dr. Chris Johnson

Dr. Susan Korrick

Dr. Michael Kosnett

Dr. Roman Lanno

Mr. Richard Poirot

Dr. Joel Pounds

Dr. Michael Rabinowitz

Dr. William Stubblefield

Dr. Ian von Lindern

Dr. Gail Wasserman

Dr. Michael Weitzman

Mr. Aaron Yeow, Designated Federal Officer (DFO)

Dr. John Vandenberg, EPA National Center for Environmental Assessment (NCEA)

Dr. Ellen Kirrane, EPA NCEA

Ms. Debra Walsh, EPA NCEA

Dr. Bryan Hubbell, EPA Office of Air Quality and Planning Standards

Dr. Zachary Pekar, EPA OAQPS

Other Attendees (See Attachment B)
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Wednesday, July 20, 2011

Opening Remarks

Mr. Aaron Yeow, the DFO for the CASAC Lead Review Panel, opened the meeting. He noted 

that as required under the Federal Advisory Committee Act (FACA), the Panel’s deliberations 

are held in public with advanced notice given in the Federal Register1, and the meeting minutes 

will be made publicly available after the meeting. He noted that the Panel received one request 

from the public to present oral comments, and received one set of written public comments. He 

also noted that the Panel members are subject to compliance with federal ethics regulations and 

conflict-of-interest laws that pertain to them. He then turned the meeting over to Dr. Vanessa Vu, 

the Director of the SAB Staff Office, who welcomed everyone and thanked them for their public 

service. She indicated that the purpose of the meeting was for the Panel to peer review EPA's

Integrated Science Assessment for Lead (First External Draft - May 2011)2and to provide 

consultative advice on EPA’s Review of the National Ambient Air Quality Standards for Lead: 

Risk and Exposure Assessment Planning Document (June 2011)3. She then turned the meeting 

over to Dr. Chris Frey, Chair of the CASAC Lead Review Panel.

Dr. Frey welcomed everyone, and had the Panel introduce themselves. He reiterated the purpose 

of the meeting and the expectations of the results from the meeting. He reviewed the Agenda4, 

and introduced Dr. John Vandenberg, from EPA’s National Center for Environmental 

Assessment (NCEA) for his presentation.

EPA Presentation

Dr. John Vandenberg, EPA NCEA, made a presentation5to the Panel. He provided a description 

of the Integrated Science Assessment (ISA) document, the National Ambient Air Quality 

Standard (NAAQS) review process, and reviewed the schedule for the current NAAQS review. 

He then turned it over to Dr. Ellen Kirrane, who provided an overview of the ISA and the charge 

questions. Ms. Debra Walsh then provided an overview of the Health and Environmental 

Research Online (HERO) system.

Public Comment

Dr. Craig Boreiko, International Lead Zinc Research Organization, made an oral statement and 

indicated that he also submitted written comments6. He indicated that the causality criteria set 

forth in the ISA were not rigorously applied. He noted that little attention was paid to the 

causality criteria, particularly with respect to confounders in the lead epidemiology studies. 

Charge Question 1 - Causal Framework / Study Selection

The Panel members generally agreed that the criteria of using epidemiological studies within one 

order of magnitude at the general population blood lead range was reasonable, especially for a 

document that intends to focus on environmental lead exposures. The members found the Health 

and Environmental Research Online (HERO) system to be helpful. One member expressed 

concern that limiting the analysis to just one order of magnitude of current exposure excludes 
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90% of the world. There was discussion on the NAAQS process and that the role of the ISA is to 

aid the development of the Lead NAAQS for the United States. 

Charge Question 3 - Ambient Air

The Panel members generally found the document to be well written and comprehensive. Some 

of the Panel members noted that there was not any discussion on what EPA is doing to develop a 

better high-volume sampler. Although the ISA might not be the best place to discuss the 

development of a new high-volume sampler, the members wanted to reiterate CASAC’s previous 

recommendations for the need for such a sampler, early on in the NAAQS review process, and 

not wait until the implementation stage, at which point it would be too late to develop it. It was 

also noted that the shutdown of the Herculaneum smelter presents an opportunity to 

prospectively study the impacts of air lead to soil lead. Other members recommended that the 

chapter needs to briefly summarize the current state of the science to provide context to the new 

studies. The Panel members had several issues with the accuracy of some of the particle size Pb 

comparisons and recommends that EPA screen the data for very low concentrations that may 

have poor precision and re-check the calculations. The members also had concerns about several 

aspects of the reported Pb emissions inventory data, including the relative importance of 

resuspended Pb from soils near historical sources (including roadways), and emissions from 

aviation gasoline combustion. 

Charge Question 4 – Exposure, Biomarkers, Toxicokinetics

Charge Question 4a – Exposure and Toxicokinetics

The Panel members noted that this chapter was pretty well-put together and found that the 

discussion of the effects of the reduction in air lead levels from the phase out of gasoline to be 

good. However, little emphasis is given to attributing the reductions in air lead levels to the 

shutdown of stationary sources throughout the country that was occurring at the same time. The 

members also thought it would be useful for the chapter to include a summary of how lead 

concentrations in other media have changed over the years.

Following the lunch break, EPA provided some clarification of the NAAQS process and the 

roles of the ISA and Risk and Exposure Assessment (REA).

Charge Question 4b – Biological Markers

The Panel recommended that the ISA provide greater distinction in the definition of the terms 

absorption and bioavailability and to use the terms consistently according to that distinction. The 

members also recommended defining the distinction between validation and application of 

biomarkers for exposure, body burden, dose, and risk. There was discussion regarding several 

figures pertaining to biokinetic modeling and it was recommended that greater explanation be 

given to the biokinetic modeling assumptions and comparisons to epidemiological data as 

validation.
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Charge Question 4c – Empirical Modeling

The Panel members found that inclusion of additional studies from which to estimate air Pb to 

blood Pb slope factors was a positive advancement from the previous NAAQS, which relied on 

just one or two studies, but would like to see how these slope factors compared to the one used in 

the previous NAAQS review. One member developed several figures to illustrate the potential 

change (reduction) in blood Pb concentrations as a function of reductions in the current NAAQS

and recommended that the ISA contain similar figures.

Charge Question 5 – Integrated Health Effects of Lead Exposure

Charge Questions 5a and 5e – Modes of Action and Dose-Response

The Panel members generally found that the discussion of the potential modes of action 

underlying the health effects of Pb exposure was thorough and inclusive of the current scientific 

literature and that no known modes of action have been left out. They found that some cases 

studies were not presented in sufficient detail to make conclusions regarding the mechanisms of 

action. They found that the additional evidence since 2006 for a non-linear dose-response curve 

was appropriately cited and provides further support for the non-linearity of the dose response 

curve. They noted that the non-linear dose-response curve is also supported by the animal 

literature.

Charge Questions 5band 5c – Health Endpoints 

The Panel members generally found the discussion of specific health endpoints in this chapter to 

be sufficiently broad in scope, and inclusion of additional health endpoints was not required. The 

members recommended a more rigorous and transparent “weight of the evidence” analysis to 

establish the extent of any causal relationship and that the analysis should devote more attention 

to the limitations of the existing studies with respect to consistency, reproducibility, bias, control 

for confounders, and shortcomings in statistical methodology.

Charge Question 5d – Integration of Epidemiological and Toxicological Evidence

The members found the chapter provided a comprehensive review of the human epidemiologic 

and toxicological evidence of Pb’s health effects but recommended a number of modifications to 

the chapter and identified several ways to improve the application of causal determination 

criteria to the Chapter’s conclusions.

Charge Question 7 – Ecological Effects of Lead

The Panel members generally found the ecological effects chapter to be an excellent synthesis of 

the available environmental toxicity data for Pb. The chapter focused on post-2006 data, but 

some of the values that are relied upon are somewhat dated (e.g., the 1985 Ambient Water 

Quality Criteria and the 2003 terrestrial ecological soil screening level values). It was suggested 

that high quality data might be available from non-published sources, such as data generated for 

the European Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH)

regulations and recommendations were made that these be evaluated. The members 
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recommended consistent use of the terms bioconcentration factor (BCF) and bioaccumulation 

factor (BAF) and also noted that BCF is an inappropriate measure to assess the hazard of Pb. 

Causal conclusions were only weakly supported by limited exposure data and thus should be 

reevaluated.

Charge Question 6 – Susceptible Populations and Life Stages

The members generally found that the ISA’s discussion on susceptible populations was well 

written and useful. However, they recommend that EPA be very clear on the strength of the 

literature and cautious in inferring causality. They found that the ISA would be strengthened 

with more discussion of nutritional aspects that serve to increase susceptibility, differences in 

effects by gender, more discussion of gene-environmental interactions, and more mention of 

epigenetic implications. They noted that although early development is a vulnerable time period, 

significant data also show that later periods in life are associated with significant adverse effects.

Charge Question 2 - Integrative Health and Ecological Effects Overview

The members generally supported the integrated summary being placed towards the beginning of 

the ISA as opposed to the end of the document. Overall, they found the integrated overview to be 

very helpful and well written, and the framework for characterizing the degree of causality is 

particularly useful. They recommended that care be taken to ensure that the most important

points and key features from the health effects chapter are mentioned in this overview chapter.

Dr. Frey discussed action items and the DFO recessed the meeting until the next day.

Thursday, July 21, 2011

The Panel reconvened at 8:30 am and Dr. Frey went over some scheduling items related to the 

draft letter on EPA’s ISA that the Panel will be developing. He then went over the agenda and 

turned it over to EPA for their presentation.

EPA Presentation

Dr. Zachary Pekar and Dr. Bryan Hubbell from EPA’s OAQPS presented an overview7of the 

Risk and Exposure Assessment Planning Document. Some of the topics discussed included the 

purpose of the document, an overview of the of the prior Lead NAAQS review, key areas of 

uncertainty and limitations in the prior review, and an overview of key observations in the 

current planning document.

There was some discussion between the Panel members and EPA about whether there was going 

to be an REA document. EPA indicated that they did not plan on producing an REA document 

because the recent scientific information did not warrant a new quantitative risk assessment. 

They explained that this would be documented in the policy assessment document (PAD). 

Several members indicated that the documentation in the PAD is too late in the process and 

wanted to see something sooner. Several members also indicated that they would like to see 
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additional modeling, particularly in regards to an airport case study to assess the impact of 

aviation gasoline.

Public Comment

There were no public comments on the REA Planning document.

Health Risk Assessment Issues

The Panel proceeded to discuss their comments on the human health risk assessment issues in the 

REA Planning Document. Several members commented that the document was well-written and 

coherent. Some members agreed with EPA that there is not sufficient new data to warrant a new 

quantitative risk assessment. Other members raised the issue of airports and aviation gasoline 

and perhaps the need for some additional case studies/modeling. 

Welfare Assessment Issues

The members generally found the document to be well-written and well-organized. Some 

members pointed out that there is a huge difference in terms of perspective of the importance of 

lead in health risk assessment versus ecological risk assessment. They did not consider lead to be 

in the top list of things that reduce the functioning of ecosystems and the production of 

ecosystem services. Some members agreed that the critical loads approach was the way to go, 

but were concerned that there would ever be enough sufficient data. Another member indicated 

that the weakest link in the risk assessment was the linkage between air concentrations of lead 

and media concentrations of lead.

Summary and Action Items

With the discussion on the REA Planning Document concluded, Dr. Frey then proceeded with a 

summary of the Panel’s consensus responses to the charge questions on the ISA. He presented a 

summary of the major points discussed and agreed upon by the Panel. He then discussed the next 

steps and action items.

With the business concluded, the Designated Federal Officer adjourned the meeting at 11:55 AM 

ET.

Respectfully Submitted: Certified as Accurate:

/Signed/ /Signed/

Mr. Aaron Yeow Dr. H. Christopher Frey

Designated Federal Officer Chair

EPA SAB Staff Office CASAC Lead Review Panel
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NOTE AND DISCLAIMER: The minutes of this public meeting reflect diverse ideas and 

suggestions offered by Panel members during the course of deliberations within the meeting. Such 

ideas, suggestions and deliberations do not necessarily reflect consensus advice from the Panel 

members. The reader is cautioned to not rely on the minutes to represent final, approved, consensus 

advice and recommendations offered to the Agency. Such advice and recommendations may be 

found in the final advisories, commentaries, letters or reports prepared and transmitted to the EPA 

Administrator following the public meetings.
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Materials Cited

The following meeting materials are available on the CASAC website: 

http://www.epa.gov/casac, at the July 20 - 21, 2011 CASAC Lead Review Panel Meeting page:

 

1

Federal Register Notice Announcing the Meeting

2

Integrated Science Assessment for Lead (First External Draft - May 2011)

3 Review of the National Ambient Air Quality Standards for Lead: Risk and Exposure Assessment Planning 

Document (June 2011).

4 Agenda for July 20-21, 2011 Public Meeting

5 EPA Presentation on the Lead Integrated Science Assessment (ISA)

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Public Comments from Craig Boreiko, International Lead Zinc Research Organization (ILZRO)

7EPA Presentation on the Lead Risk and Exposure Assessment (REA) Planning Document
A-1

ATTACHMENT A - ROSTER

U.S. Environmental Protection Agency

Clean Air Scientific Advisory Committee

CASAC Lead Review Panel (2010-2013)

CHAIR

Dr. H. Christopher Frey, Professor, Department of Civil, Construction and Environmental 

Engineering, College of Engineering, North Carolina State University, Raleigh, NC

MEMBERS

Mr. George A. Allen, Senior Scientist, Northeast States for Coordinated Air Use Management 

(NESCAUM), Boston, MA

Dr. Herbert Allen, Professor Emeritus, Department of Civil and Environmental Engineering, 

University of Delaware, Newark, DE

Dr. Richard Canfield*, Senior Research Associate, Division of Nutritional Sciences, Cornell 

University, Ithaca, NY

Dr. Deborah Cory-Slechta, Professor, Department of Environmental Medicine, School of

Medicine and Dentistry, University of Rochester, Rochester, NY

Dr. Cliff Davidson, Professor, Civil and Environmental Engineering, Syracuse University, 

Syracuse, NY

Dr. Philip E. Goodrum, Senior Project Manager, Environmental Resources Management 

(ERM), Dewitt, NY

Dr. Sean Hays, President, Summit Toxicology, Allenspark, CO

Dr. Philip Hopke, Bayard D. Clarkson Distinguished Professor, Department of Chemical and 

Biomolecular Engineering, Clarkson University, Potsdam, NY

Dr. Chris Johnson, Professor, Department of Civil and Environmental Engineering , Syracuse 

University, Syracuse, NY

Dr. Susan Korrick, Assistant Professor of Medicine , Department of Medicine, Brigham and 

Women's Hospital, Channing Laboratory, Harvard Medical School, Boston, MA
A-2

Dr. Michael Kosnett, Associate Clinical Professor, Division of Clinical Pharmacology and 

Toxicology, Department of Medicine, University of Colorado Health Sciences Center, Denver, 

CO

Dr. Roman Lanno, Associate Professor and Associate Chair, Department of Evolution, 

Ecology, and Organismal Biology, Ohio State University, Columbus, OH

Mr. Richard L. Poirot, Environmental Analyst, Air Pollution Control Division, Department of 

Environmental Conservation, Vermont Agency of Natural Resources, Waterbury, VT

Dr. Joel Pounds, Laboratory Fellow, Cell Biology & Biochemistry, Biological Sciences 

Division, Pacific Northwest National Laboratory, Richland, WA

Dr. Michael Rabinowitz, Geochemist, Marine Biological Laboratory, Newport, RI

Dr. William Stubblefield, Senior Research Professor, Department of Molecular and 

Environmental Toxicology, Oregon State University, Corvallis, OR

Dr. Ian von Lindern, President, TerraGraphics Environmental Engineering, Inc., Moscow, ID

Dr. Gail Wasserman, Professor of Clinical Psychology in Child Psychiatry, Division of Child 

and Adolescent Psychiatry, College of Physicians and Surgeons, Columbia University, New 

York, NY

Dr. Michael Weitzman, Professor, Pediatrics; Psychiatry, New York University School of 

Medicine, New York, NY

*Did not participate in this review.

SCIENCE ADVISORY BOARD STAFF

Mr. Aaron Yeow, Designated Federal Officer, U.S. Environmental Protection Agency, Science 

Advisory Board (1400R), 1200 Pennsylvania Avenue, NW, Washington, DC, Phone: 202-564-

2050, Fax: 202-565-2098, (yeow.aaron@epa.gov)
B-1

ATTACHMENT B – Other Attendees

CASAC Lead Panel Public Meeting

July 20, 2011

Name Affliation

Boreiko, Craig International Lead Zinc Research Organization

Brightwell, Holly* Texas Commission on Environmental Quality

Brown, James EPA

Datko, Laura EPA

Davis, Allen EPA

Dietert, Rodney Cornell University

Dubois, Jean-Jacques EPA

Dutton, Steve EPA

Dzubow, Rebecca* EPA

Fairbrother, Anne Exponent

Gandy, Jay University of Arkansas for Medical Sciences

Gonick, Harvey UCLA

Hines, Erin EPA

Hoyer, Marion EPA

Hubbard, Heidi ICF

Johns, Doug EPA

Kotchmar, Dennis EPA

Lassiter, Meredith EPA

Long, Thomas* EPA

Lorang, Ellen EPA

McDow, Steve EPA

Meacham, Connie EPA

Mendez, Bill ICF

Murphy, Deirdre EPA

Nystrom, Marci* California Air Resources Board

Orlin, David EPA

Owens, Beth EPA

Parker, Stuart* InsideEPA

Patel, Molini EPA

Pedde, Meredith* EPA

Pinto, Joseph EPA

Rajan, Pradeep EPA

Richmond-Bryant, Jennifer EPA

Ross, Mary EPA

Rothenberg, Stephen National Institute of Public Health
B-2

Selgrade, Mary Jane ICF

Sheedy, Keith* Texas Commission on Environmental Quality

Shumake, Katie EPA

Siporin, Kaylyn EPA

Stanek, Lindsay EPA

Svendsgaard, Dave EPA

Tennant, Ginger EPA

Tonne, Jay* Texas Commission on Environmental Quality

Vanderpool, Robert EPA

Vinikoor-Imler, Lisa EPA

Volpe, Rosalind ILZRO

Walsh, Debra EPA

Weaver, Virginia Johns Hopkins University

Wiesskopf, Marc EPA

Wise, John University of Southern Maine

Wright, Robert Harvard University

Wright, Rosalind Harvard University

Young, Brianna EPA

*Participated via teleconference

July 21, 2011

Name Affliation

Boreiko, Craig ILZRO

Brightwell, Holly* Texas Commission on Environmental Quality

Deitert, Rodney Cornell University

Dubois, Jean-Jacques EPA

Dzubow, Rebecca* EPA

Fairbrother, Anne Exponent

Hines, Erin EPA

Hoyer, Marion EPA

Hubbard, Heidi ICF

Kotchmar, Dennis EPA

Lassiter, Meredith EPA

Long, Thomas* EPA

Mendez, Bill ICF

Murphy, Deirdre EPA

Nystrom, Marci* California Air Resources Board

Orlin, David EPA

Owens, Beth EPA
B-3

Parker, Stuart* InsideEPA

Patel, Molini EPA

Pedde, Meredith* EPA

Rajan, Pradeep EPA

Richmond-Bryant, Jennifer EPA

Ross, Mary EPA

Rothenberg, Stephen National Institute of Public Health

Sheedy, Keith* Texas Commission on Environmental Quality

Tennant, Ginger EPA

Tonne, Jay* Texas Commission on Environmental Quality

Volpe, Rosalind ILZRO

Weaver, Virginia Johns Hopkins University

Wise, John University of Southern Maine

*Participated via teleconference