# Project Work Plan for Revised Air Quality Criteria for Lead

Notice This document is a preliminary draft. It has not been formally released by EPA and should not at this stage be construed to represent Agency policy. It is being circulated for comment on its technical accuracy and policy implications. 

# EPA United States Environmental Protection AgencyJanuary 2005 DRAFT – DO NOT QUOTE OR CITE NCEA-R-1465

January 2005 CASAC Review Draft



# Project Work Plan for Revised Air Quality Criteria For Lead

National Center for Environment Assessment Office of Research and Development U. S. Environmental Protection Agency

Research Triangle Park, NC 27711January 2005 DRAFT – DO NOT QUOTE OR CITE i 

### DISCLAIMER This document is an external draft for review pur poses only and does not constitute U.S. Environmental Protection Agency policy. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.



### PREFACE This project work plan has been prepared as a managerial and management information tool for the U.S. Environmental Protection Agency's National Center for Environmental Assessment Division in Research Triangle Park, NC. It may be modified and amended from time to time, as necessary, to reflect actual project requirements and progress. As a result, any proposedschedules and outlines, or any lists of technical coordinator assignments, authors, or reviewers are subject to change.January 2005 DRAFT – DO NOT QUOTE OR CITE ii 

### TABLE OF CONTENTS

DISCLAIMER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i PREFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i TABLE OF CONTENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii I. INTRODUCTION ........................................................1 A. LEGISLATIVE BACKGROUND ........................................1 B. REGULATORY BACKGROUND ........................................2 C. PROJECTED SCHEDULE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 II. SCIENTIFIC BACKGROUND AND KEY ISSUES ............................6 A. LEAD AS A MULTIMEDIA ENVIRONMENTAL CONTAMINANT ...........6 B. HEALTH EFFECTS OF EXPOSURE TO LEAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 C. ECOLOGICAL EFFECTS OF EXPOSURE TO LEAD . . . . . . . . . . . . . . . . . . . . . . 10 III. ORGANIZATIONAL STRUCTURE AND PREPARATION/REVIEW PROCESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 A. ORGANIZATION AND CONTENT OF REVISED LEAD DOCUMENT . . . . . . . 14 B. METHODS AND PROCEDURES FOR DOCUMENT PREPARATION . . . . . . . . 15 C. PERSONNEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 D. APPROACH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 E. PUBLIC AND SCIENTIFIC REVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 APPENDIX A: Proposed Contents of Revised Air Quality Criteria for Lead . . . . . . A-1 APPENDIX B: EPA Work Group for Air Quality Criteria for Lead . . . . . . . . . . . . . . B-1 APPENDIX C: NCEA-RTP Project Team and Other Technical Consultants . . . . . . . C-1 APPENDIX D: Science Advisory Board Clean Air Scientific Advisory Committee Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1January 2005 DRAFT – DO NOT QUOTE OR CITE 1 

# I. INTRODUCTION
A. LEGISLATIVE BACKGROUND Two sections of the Clean Air Act (CAA) governthe establishment, review, and revision of National Ambient Air Quality Standards (NAAQS). Section 108 (42 U.S.C. 7408) directs the Administrator of the U.S. Environmental Protection Ag ency (EPA) to list certain air pollutants that may be reasonably anticipated to endange r public health or welfare and to issue air quality criteria for them. These air quality criteria (scientific bases for NAAQS) ar e to reflect the latest scientific information useful in indicating the kind and extent of all identif iable effects on public health or welfare that may be expected from the presence of a given “criteria” pollutant in ambient air. Section 109(a) of the CAA (42 U.S.C. 7409) directs the Administrator of EPA to propose and promulgate primary and secondary NAAQS for pollutants identified under Section 108. Section 109(b)(1) defines a primary standard as one that, in the judgment of the Administrator, is requisite to protect the public health (see inset) based on the criteri a and allowing for an adequate margin of safety. The secondary standard, as defined in Section 109(b)(2), must specify a level of air quality that, in the judgment of the Administrator, is requisite to protect the public welfare (see inset) from any known or anticipated adverse effects associated with the presence of the pollutant in ambient air, based on the criteria.

Section 109(d) of the CAA (42 U.S.C. 7409) requir es periodic review and, if appropriate, revision of existing criteria and standards. If, in the Admini strator's judgment, the Agency's review and revision of criteria make appropriate the proposal of new or revi sed standards, such standards are to be revised and promulgated in accordance with Section 109(b). Altern atively, the Administrator may find that revision 

### PUBLIC HEALTH EFFECTS

C Effects on the health of the general population, or identifiable groups within the population, who are exposed to pollutants in ambient air

C Effects on mortality

C Effects on morbidity

C Effects on other health conditions including indicators of:

C pre-morbid processes,

C risk factors, and

C disease 

### PUBLIC WELFARE EFFECTS

C Effects on personal comfort and well-being

C Effects on economic values

C Deterioration of property

C Hazards to transportation

C Effects on the environment, including:

C animals

C climate

C crops
C materials

C soils C vegetation

C visibility

C water

C weather

C wildlifeJanuary 2005 DRAFT – DO NOT QUOTE OR CITE 2 of the standards is inappropriate and conclude the review by leavi ng the existing standards unchanged. Section 109 of the Clean Air Act (42 U.S.C. 7409) also requires that the criteria and NAAQS be reviewed by an independent scientific review group, those review responsibilities being met by the Clean Air Scientific Advisory Committee (CASAC) of EPA’s Science Advisory Board (SAB).


### B. REGULATORY BACKGROUND On October 5, 1978 the EPA promulgated primary and secondary NAAQS for lead, under Section 109 of the CAA (43 FR 46258). The primary st andard and the secondary standard are the same: 1.5 μg/m 3 as a quarterly average (maximum arithmetic m ean averaged over a calendar quarter). The standards were based on the EPA’s 1977 Air Quality Cr iteria for lead. Subsequent regulations reducing the use of lead additives in gasoline were promul gated in 1985 (50 FR 9386), leading to substantial reductions in ambient air lead concentrations. In 1986, the EPA published a revised Air Quality Criteria Document for Lead (Lead AQCD). The 1986 AQCD assessed newly available scientific informati on on the health and welfare effects associated with exposure to various concentrations of leadin ambient air. The 1986 AQCD reviewed literature through 1985 for information relevant to derivation of air quality criteria for lead. The document was principally concerned with the health and welfare e ffects of lead, but other scientific data were also discussed in order to provide a better understanding of the pollutant in the environment. Thus, the 1986 document included chapters that discussed the atmo spheric chemistry and physics of the pollutant; analytical approaches; environmental concentrations; human exposure and dosimetry; physiological, toxicological, clinical and epidemiological aspects of l ead health effects; and lead effects on ecosystems. An Addendum to the 1986 Lead AQCD was also pub lished along with it in 1986 (U.S. Environmental Protection Agency, 1986). Subsequently, a supplement to the 1986 Lead AQCD/Addendum was published by EPA in 1990 (U.S. Environmental Protection Agency, 1990). That 1990 supplement evaluated still newer information emerging in the pub lished literature concerning (1) lead effects on blood pressure and other cardiovascular endpoints and (2) the effects of lead exposure during pregnancy or early postnatally on birth outcomes and/or on the neonatal physical and neuropsychological development of affected children. The evaluations contained in the 1986 Lead AQCD/Addendum and the 1990 Supplement provided scientific inputs to support decision-making with regard to review and, as appropriate, revision of the Lead NAAQS and they were drawn upon by EPA’s Office of Air Quality Planning and Standards (OAQPS) in preparation of an associated Lead Staff Pa per. After consideration of evaluations contained in these documents, EPA chose not to propose revision of the Lead NAAQS.January 2005 DRAFT – DO NOT QUOTE OR CITE 3 Changes in relative contributions of various lead sources and exposure pathways to human exposures in the United States, and EPA actions to reduce such exposures also provide important background for this review. Since 1978, the amount of lead emitted into the air nationally has markedly declined. From 1982 to 2002, for example, lead emi ssions into the air decreased by 93 percent, and the average air quality concentration of lead decreased by 94 percent from 1983 to 2002 (http://www.epa.gov/airtrends/lead2.html). Total l ead emissions into the air decreased from about 220,000 tons in 1970 to less than 4,000 in 1999. This d ecline is mainly attributable to EPA’s regulatory efforts to reduce the content of lead in gasolin e (http://www.epa.gov/airtrends/lead2.html), which has substantially altered basic patterns of air lead emi ssions in the United States. Emissions from stationary sources have also been greatly reduced (http:// www.epa.gov/airtrends/lead2.html, Fig. 2-11); however, given the even greater reductions in emissions fro m transportation sources, industrial processes (including smelters and battery manufacturers) now constitute a larg er percentage of remaining lead emissions to the atmosphere ( id. , Fig. 2-12). (See generally (http://www.epa.gov/airtrends/lead2.html). In short, lead emissions into the atmosphere decreased greatly in th e 1980's and 1990's, a trend that has continued to the present. As a consequence, airborne lead now re presents only a relatively small component of total exposure to lead, such that the principal sources of U.S. lead exposure in the most sensitive population (young children) are through non-inhalation pathways (suc h as lead in deteriorating paint, food, drinking water, dust, and historically contaminated soil). Since the 1980's, EPA has played a major role in working to reduce the main sources of lead exposure for most children, including deteriorating l ead-based paint, lead contaminated dust, and lead contaminated residential soil (http://www.epa.gov/lead /). For example, EPA has established standards for lead-based paint hazards and lead dust cl eanup levels in most pre-1978 housing and childoccupied facilities, and is now developing standards for those conducting renovation activities that create lead-based paint hazards and for the management and disposal of lead-based debris (http://www.epa.gov/lead/regulation.htm). Also, EPAhas developed standards for management of lead in solid and hazardous waste, oversees the cleanup of lead contamination at Superfund facilities, and has issued regulations to reduce lead indrinking water (http://www.epa.gov/lead/sources.htm). Beyond specific regulatory actions, the Agency’s Lead Awareness Program continues to work to protect human health and the environment agains t the dangers of lead by conducting research and designing educational outreach efforts and materials (http://www.epa.gov/lead/). Since the 1980's, EPA has also promulgate d regulations under section 112 of the Act, 42 U.S.C. § 7412, to address emissions of lead components and other toxic pollutants from both primary lead smelters and secondary lead smelters (40 CFR Subparts X and TTT). Under section 112(d), these emission standards are to require “the maximum degree of reduction in emissions” that are “achievable.”January 2005 DRAFT – DO NOT QUOTE OR CITE 4 EPA promulgated section 112(d) standards for secondarylead smelters on June 23, 1995 (60 Fed. Reg. 3587) and revised them on June 13, 1997 (62 Fed. Reg. 32209) followed by promulgation of section 112(d) standards for primary lead smelte rs on June 4, 1999 (64 Fed. Reg. 30194). 

### C. PROJECTED SCHEDULE On November 9, 2004, EPA’s National Center for Environmental Assessment Division in Research Triangle Park, NC (NCEA-RTP) announced official in itiation of the current periodic review of air quality criteria for lead. More specifically, under processes est ablished in Sections 108 and 109 of the CAA, the EPA began by announcing in the Fe deral Register (69 FR 64,926) the formal commencement of the review with a call for information. In addition, EPAhas prepared this Lead AQCD Work Plan, a draft of which is now being made available for review byCASAC and the public, to communicate the process and timeline for development of a revised Lead AQCD. After carefully assessing and evaluating pertinent new studies, the EPA will first prepare preliminary draft chapters for a revised criteria document and subject them to expert review at public workshops . After consideration of comments received at the workshops, appropriate revisions will be made in the draft materials and a First External Review Draft of the entire revised document will be made available for review and comment by CASAC and the public. EPA expects that, after consideration of CASAC and public comments, it will be necessary to prepare a Second External Review Draft of the revised Lead AQCD for further review by CASAC and the public before EPA completes the final version of the LeadAQCD. Publication of the final document and its availability to the public will be announced in the Fede ral Register. Table 1 shows the projected schedule for the criteria document revision process. Drawing upon evaluations in the Lead AQCD and other lead exposure/risk analyses, the EPA’s Office of Air Quality Planning and Standards (OAQ PS) staff will prepare a draft Lead Staff Paper assessing policy implications of key information in the Lead AQCD and posing possible options for the EPA Administrator to consider regarding whether to retain or, if appropriate, revise the Lead NAAQS. The draft Staff Paper and analyses will also be ma de available for review by CASAC and the public. Taking into account CASAC and public comments, final revisions will be made in the Lead Staff Paper, and it will provide information for decisions to be made by the EPA Administrator regarding possible retention or revision of the Lead NAAQS.January 2005 DRAFT – DO NOT QUOTE OR CITE 5 

### Table 1. Proposed Schedule for Developmen t of Revised Lead Air Quality Criteria Document (Pb AQCD) 1 Major Milestones Target Dates 1. Literature Search Ongoing 2. Federal Register Call for Information November 2004 3. Prepare Draft Pb AQCD Project Work Plan Nov-Dec 2004 4. Release Draft Project Plan for Public Comment/CASAC Review January 2005 5. Public Comment Period Jan/Feb 2005 6. CASAC/SAB Public Meeting to Review Project Work Plan March 2005 7. Workshop Drafts of Pb AQCD Chapters May/June 2005 8. Peer Consultative-Review Workshop(s) July/August 2005 9. Release First External Review Draft January 2006 10. Public Comment Period (90 days) Feb-April 2006 11. CASAC/SAB Public Review Meeting (First Ext. Rev. Draft) April 2006 12. Release Second External Review Draft September 2006 13. Public Comment Period (60 days) Oct-Nov 2006 14. CASAC/SAB Public Review Meeting ( Second Ext. Rev. Draft ) December 2006 15. Final Lead AQCD February 2007

1 Proposed schedule may be modified from time to time, as n ecessary, to reflect actual proj ect requirements and progress.January 2005 DRAFT – DO NOT QUOTE OR CITE 6 

# II. SCIENTIFIC BACKGROUND AND KEY ISSUES Numerous issues were identified by author s and reviewers of the 1986 Lead AQCD/Addendum and the 1990 Supplement (U.S. Environmental Protec tion Agency, 1986, 1990) as being relevant to the development of lead criteria. Additional issues we re identified in the course of public discussion and CASAC review of draft versions of those earlier AQC D materials and/or the associated Lead Staff Paper, and some further issues have begun to emerge since then as being of potential public health concern. By way of introduction to the types of issues anticipat ed to be considered in the current lead criteria review, the next several sections each open with concise presentation of some pertinent background information on a given general category or topic, fo llowed by listing of a number of the more important issues as illustrative of the types of questions to be c onsidered in the current review of lead criteria. Many of these issues were addressed by previous review s. This review will consider any newly available evidence as it may pertain to potential affirmation or revision of previous ly-stated key findings or conclusions.


### A. LEAD AS A MULTIMEDIA ENVIRONMENTAL CONTAMINANT Lead is a toxic metal that can produce a variety of physiological and, ultimately, pathological effects in humans and can also have adverse effect s on the environment. As illustrated in Figure 1, human exposure occurs through multiple pathways, includi ng primarily ingestion of lead in media such as food, water, soil, and dust, as well as inhalation of ai rborne lead. Because health effects in humans are associated with varying levels of lead in the bl ood and because all exposure pathways contribute to blood lead levels, health risks are a function of total expos ure. Thus, the evaluation of potential health risks associated with exposures to concentrations of lead in the air must also take into account estimated exposures and blood lead impacts of lead derived from other media (e.g., food, water, etc.). As a result, considerable attention will be accorded in the revised Lead AQCD to delineation of information useful in facilitating understanding of lead as a multimedia envi ronmental contaminant, including characterization of relative contributions of vari ous exposure pathways to lead burdens in humans and ecosystems and relationships of such lead burdens to conseque nt human health and environmental effects. Examples of important key issues related to de lineation of lead as a multimedia environmental contaminant are provided below.

1. Physical and Chemical Properties of Lead and Measurement Methods



### • What are important chemical and physical features of inorganic lead and organic lead compounds

encountered in the environment?January 2005 DRAFT – DO NOT QUOTE OR CITE 7 

### • What are key features of sampling and analytic methods employed for measurement of lead in

environmental and biological media?



### • What are appropriate quality assurance/quality control approaches to help ensure reliability of

such measurements? 2. Sources, Emissions, Transport, and Environmental Fate of Atmospheric Lead



### • Long-Term Historic Trends in Atmospheric L ead Emissions and Environmental Contamination.



### • What are more recent trends in atmospheric emissions in the United States since the 1970's?



### • How important is the downward deposition of lead onto surfaces accessible by humans?



### • What are the spatial concentration patterns of anthropogenic lead emissions and how do these differ from natural emissions?



### • What fraction of observed U.S. ambient air lead c oncentrations can be attributed to anthropogenic

emission sources?



### • To what extent does long-range transport of lead emitted in other countries contribute to U.S.

ambient air lead levels? Figure 1. Principal pathways of lead from the environment to human consumption. Heavy arrows are those pathways discussed in greatest detail in the 1986 Lead AQCD. Source: U.S. Environmental Protection Agency, Ai r Quality Criteria for Lead, Volume II of IV, EPA/600/8-83/028bF (June 1986).January 2005 DRAFT – DO NOT QUOTE OR CITE 8 3. Multimedia Human Exposure and Dosimetry



### • What are the main multimedia/exposure pathways accounting for human environmental lead

exposures in the United States since the 1970's?



### • What are current typical lead concentrations currently encountered by sensitive U.S. populations

via different major exposure pathways, e.g., air, food, water, etc.?



### • What is the current status of population-based information on total human lead exposure and spatial and temporal patterns of exposures of sensitive population groups?



### • What tissue or fluid lead concentrations can ser ve as useful biomarkers of short- or long-term lead exposure?



### • What other types of biomarkers are useful as indices of short- or long-term lead exposures?



### • How do social factors (e.g., human activity patterns and variable avoidance behaviors) affect lead

exposures of sensitive population groups?



### • What genetic/physiologic factors influence lead exposure and the magnitude of lead

uptake/biological retention?



### • What are features of currently available biokinetic models that are useful for projecting likely

impacts of multimedia human lead exposures (via air, food, water, etc.) on internal body burdens as indexed by blood lead levels, etc?



### B. HEALTH EFFECTS OF EXPOSURE TO LEAD Decision-making underlying establishment of the 1978 primary Lead NAAQS took into account consideration of the following key issues: (1) Determination of blood lead (PbB) concentrations associated with unacceptable risk of adverse health effects, especially in infants and young children as key sensitive population; (2) Characterization of PbB distributions typical of U.S. pediatric populations; (3) Determination of target level for average PbB concentration to keep PbB levels of given percentage of sensitive population group below concentr ations associated with unacceptable health risks; (4) Characterization of typical relative contri butions of different multimedia lead exposure pathways (food, water, air, soil, etc.) to U.S. pediatric PbB levels; and (5) Determination of allowable air lead c oncentrations (i.e., the NAAQS) , taking into account average contributions from other multimedia lead exposure pathways (e.g., via food, water, etc.). One of the most controversial and intensely de bated issues was the first listed above, i.e., the determination of blood lead levels associated with unacceptable risk of adverse health effects. ThisJanuary 2005 DRAFT – DO NOT QUOTE OR CITE 9 determination was based on the 1977 Pb AQCD character ization of health effects associated with acute and more chronic exposure to lead resulting in intern al lead body burdens indexed across a wide range of blood lead levels in adults and, of most concern, in young children, infants, and the unborn (in-utero) fetus. This included qualitative delineation of typ es of lead effects documented by clinical and epidemiological observations (as also supported by experimental animal studies) and characterization of quantitative dose-response relationships. The latter in cluded estimation of lowest-observed effect levels for induction of: (a) clearly adverse, clinically evident classical signs and symptoms of acute lead poisoning, such as (1) indications of life-threatening lead encephalopathy (serious central nervous system damage most often seen in infants and young child ren and often leading to permanent severe mental retardation and learning disabilities among survivors) doc umented to be associated with acute high-level lead exposures resulting in very high blood-lead leve ls or (2) other signs of peripheral nerve damage (as indexed, for example, by slowed nerve conducti on velocities), anemia, indications of renal damage and/or gastrointestinal symptoms (e.g., colic) ob served in young children at somewhat lower blood lead levels (the occurrence of a sufficiently severe cons tellation of the above types of acute lead poisoning signs and symptoms typically warranting chelation and other types of immediate medical treatment). It also included (b) much more subtle and difficult to detect indications in asymptomatic infants and children of less severe but still serious nervous system impacts (as indexed by IQ decrements or various other types of sensitive tests of neurobehavioral or psychomotor functions) and/or more moderate red blood cell impacts reported to occur at still lower blood lead levels but seen as likely collectively constituting adverse health effects; and (c) muchsmaller magnitude biological or pathophysiological effects of lead unlikely to be of medical concern (e .g., initial biochemical impacts on heme synthesis that occur starting at very low blood lead levels and increase in magnitude as blood lead levels become more elevated). Subsequent studies assessed in the 1986 Lead AQCD/Addendum and the 1990 Supplement provided further evidence substantiating the above types of findings and reported observed effect levels for neurobehavioral impacts that extended to s till lower PbB values than previously reported. Among the more important health-related issues that are anticipated to be considered in the current Lead NAAQS review as part of the basis for deci sions on the primary Lead NAAQS are those listed below.



### 1. Biological Mechanisms of Action



### C What are mechanisms and time-courses associated with lead-induced subcellular, cellular, and tissue injury, repair, and/or remodeling?



### C What are the effects of age, gender, and pre-existing disease on cellular and tissue responses to lead-induced injury?January 2005 DRAFT – DO NOT QUOTE OR CITE 10 

### C In particular, to what extent does lead affect he me synthesis at varying lead exposure levels and what are consequent impacts on various tissue or organ system functions? 2. Effects of Repeated Short-term, Prolonged, or Long-term Lead Exposure on Potential Histopathologic, Pathophysiologic and Clinical Sequelae of Disease



### C What levels and/or patterns of lead exposure ar e associated with retardation of growth rate in fetuses, infants, and children?



### C What levels of exposure (indexe d by blood, bone, teeth lead levels) early in development are associated with induction of neurol ogical/neurobehavioral deficits?



### C To what extent do lead-induced neurobehavioral/g rowth effects early in development persist and have long-term sequelae?



### C To what extent does long-term lead exposur e contribute to postmenopausal osteoporosis, formation of cataracts, or other health problems encountered most typically in older population groups?



### C What evidence exists for genotoxic, carcinogenic, and/or co-carcinogenic effects of lead? 3. Sensitive Populations and Factors that Enhance Susceptibility



### C What environmental and host factors (e.g., dem ographic, socioeconomic, genetic) are associated with increased vulnerability or susceptibility to short- and long-term exposure to lead?



### C Does lead exposure exacerbate pre-existing healthconditions? If so, what is the nature of enhanced health effects in persons with pre-ex isting health conditions who are exposed to lead?



### C What are the quantitative relationships betweenambient lead exposures and the frequencies of occurrence of these effects?



### C. ECOLOGICAL EFFECTS OF EXPOSURE TO LEAD Lead occurs in various forms in the environment. Ionic lead (Pb 2+ ), lead oxides and hydroxides, and lead-metal oxyanion complexes are the general forms of lead released into soil, groundwater, and surface waters. Pb 2+is the most common and reactive form of lead, forming mononuclear and polynuclear oxides and hydroxides. The form of lead in the environment greatly influences the bioavailability and toxicity to various biota. Lead can accumulate in the terrestrial environment in soils, microorganisms, and plants. The forest canopy is the functional interface between 90 per cent of the Earth’s biomass and the atmosphere. Scavenging of atmospheric lead by foliage is a signifi cant entry route of Pb into terrestrial ecosystems. Soil-borne lead can be directly toxic to soil microorganisms and disrupt decomposition and mycorrhizalJanuary 2005 DRAFT – DO NOT QUOTE OR CITE 11 processes. Once captured, lead persists within terrestrial ecosystems for decades, if not centuries. Lead can enter adjacent aquatic systems by interactions between the terrestrial and aquatic environment. Lead can also accumulate in sediments of aquatic ecosystems and serve as a source of contamination to benthic organisms over long periods of time. Aquatic macrophytes can accumulate lead from sediments and introduce lead into the aquatic food chain through the activities of plant grazers. Uptake of lead directly from the water column can al so contribute to total lead body burdens in pelagic aquatic species. Lead can move up the food chain and ultimately impact human health through consumption of lead-tainted fish and shellfish. The previous review (U.S. Environmental Protection Agency, 1986) indicated that remaining uncertainties in available data for a number of envi ronmental effects categories increased the difficulties associated with characterizing qualitative or quantif iable risks to various components of agronomic, forested, and natural ecosystems. The fo llowing issues tend to center around addressing such uncertainties and provide an overall framework for assessing new scientific information that should likely be considered to support selection of an appropriate secondary lead NAAQS protective of crops, natural vegetation, and ecosystem components and processes.
1. Exposure Dynamics: monitoring to determine ambient lead concentrations encountered in urban and rural farm/forest areas, exposure patterns (epis odes), concentrations vs flux, relationship between chamber and field exposure data, plant uptake; a. Modeling

C What is the state of the science in modeling lead concentration gradient s and deposition velocities across plant canopies, plant communities, or multiple ecological resource landscapes?

C How precise and accurate are these models?

C How well can these models be extrapolated tempor ally and spatially within or across different

forest types, crops, watersheds, basins, ecophysi ographic regions, the urban-rural interface, etc.?

C Can passive samplers be useful to “fill in the gap s” in model-derived lead concentrations at remote

areas where continuous lead monitoring is not routinely performed? b. Exposure Regimes

C How do episodic exposures (predisposition) alter plan t or animal responses to chronic, cumulative

lead exposures?

C How do we translate results from controlled e xposure studies which are typically conducted with

single species/organisms (e.g., tree seedlings or crops) to whole trees, forest stands, farm land, lakes, estuaries, ecosystems, watersheds , airsheds, or ecophysiographic regions?

C Can data from remote sensing platforms be u seful in understanding local, regional, national,

and global lead transport and deposition?January 2005 DRAFT – DO NOT QUOTE OR CITE 12 2. Plant/Animal Response and Mode of Action: biological, chemical and physical responses, especially cellular biochemical/physiological m echanisms; individual plant sensitivity/ genetic composition; site/habitat influences; pest , disease, and abiotic stress interactions; a. Plants

C Is there new information regarding the mode of action of lead once it enters a plant?

C Are there genetic markers that can be identified using state-of-the-art molecular biological

methodologies that differentiate lead tolerant and intolerant cultivars and species?

C What is known about lead’s effects on ecosystem components singly and in combination with other

air pollutants?

C How does lead, both singly and in combination withother air pollutants, influence plant-pathogen

and plant-pest interactions? b. Wildlife

C Are lead exposure effects on wildlife similar to human exposure effects?

C Has lead altered the nutritional content of fora ge for domestic animals or wildlife populations?

C What is known about lead’s effects on faunal eco system components singly and in combination

with other air pollutants? c. Aquatic organisms

C How important is lead uptake from sediments in lead accumulation in aquatic plants and animals?

C How important is methylation in lead mob ility and bioavailability in aquatic systems?

C To what extend is lead biomagnified up the food chain? 3. Ecosystems: exposure/response relationships of sensitiv e individual plant species and forest trees to lead under ambient conditions; impact of lead exposure on interspecific competition on both aboveand below-ground interactions and on ecosystem products and services. a. Biodiversity

C Does lead influence the biodiversity of ecological systems? b. Terrestrial-Aquatic Interface

C Have terrestrial ecosystem effects of lead exposure affected aquatic ecosystems?

C Has lead altered the nutrient cycling in forest ed catchments that may manifest themselves as

changes in water chemistry at the stream and watershed levels? 4. Assessment: assessment of economic impacts on products (crops, forests, fish, shellfish, etc.) and ecosystem services, benefits derived from control of lead exposures. a. Economics

C Have new and innovative methods evolved sin ce the last criteria document for monetizing

ecosystem services and non-consumptive use products (e.g., aesthetics, recreation, plant nutritional quality for wildlife)?January 2005 DRAFT – DO NOT QUOTE OR CITE 13 C To what extent can credible estimates be derive d for economic impacts of lead on consumptive-use

ecosystem products (e.g., crop yields, fish yields, shell fisheries, and timber)? b. Scaling Up

C What recent advances, if any, now allow for locali zed or spatiotemporally disparate data sets to be

aggregated for regional ecological effects assessments?

C Can critical loads be determined for sensitive ecosystem components?January 2005 DRAFT – DO NOT QUOTE OR CITE 14 

# III. ORGANIZATIONAL STRUCTURE AND PREPARATION/REVIEW PROCESS
A. ORGANIZATION AND CONTENT OF REVISED LEAD DOCUMENT The updated Lead AQCD will critically evaluate and assess scientific information on the health and welfare effects associated with exposure to the concen trations of this pollutant in ambient air. The revised document is not intended to be an exhaustive re view of the literature. Rather, the cited references will reflect the current state of knowledge on the most relevant issues pertinent to decisions on possible Lead NAAQS revision. Although emphasis will be placed on the presentation of health and welfare effects data, other scientific data will also be pr esented and evaluated in order to provide a better understanding of the nature, sources, distribution, measure ment, and concentrations of lead in ambient air, as well as the measurement of population exposure to lead. The focus of the selected scientific information in the text will be on literature published since the previous review of the air quality criteria for l ead. Emphasis will be placed on studies conducted at or near lead concentrations found in ambient air. Othe r studies may be included if they contain unique data, such as the documentation of a previously unreported e ffect or of a mechanism for an observed effect; or if they were multiple-concentration studies desi gned to provide exposure -response relationships. Key findings and conclusions from the 1986 Lead AQCD/Addendum and 1990 Supplement will briefly be summarized at the outset of discussion of a gi ven topic, with appropriate reference back to the previous materials. Important prior studies will be more specifically discussed if they are open to reinterpretation in light of newer data and are judged to be potentiallyuseful in decisions on revision of the standards for lead. Generally, only information that has undergone scientific peer review and has been published (or accepted for publication) in the ope n literature will be considered in the criteria document. Exceptions may be made depending on th e importance of the subject information and its pertinence to criteria development for Lead NAAQS , as determined in consultation with CASAC. The proposed structure of the document will begi n with an Executive Summary and Conclusions. Chapter 1 (Introduction) will present information on the legislative background and purpose of the document, provide a brief introduction to key issu es to be addressed, and present an overview of the organization of the document. Chapter 2 will provide information on the physics and chemistry of lead, as well as sampling and analytic methods for measurement of lead concentrations in various environmental and biological media. Chapter 3 will cover sources, emissions, transport, and deposition/fate; and Chapter 4 w ill cover environmental concentr ations, patterns, and multimedia exposure pathways. Chapter 5 will discuss dosimetri c issues, focused mainly on modeling of multimedia exposure impacts on human internal lead burdens, as indexed by blood or bone lead concentrations. Chapters 6 and 7 will discuss toxicologic studies of l ead health effects in humans and laboratory animals,January 2005 DRAFT – DO NOT QUOTE OR CITE 15 as well as clinical and epidemiologic studies. Chapter 8 will then provide an integrative synthesis of key information regarding human lead exposures and health effects. Chapter 9 will deal with ecological and other environmental effects of lead. The proposed ch apter topics are provided in the inset below. See Appendix A for a more detailed outline of proposed c ontents to be included in the revised Lead AQCD.
Chapter Topics for Revised Air Quality Criteria for Lead Executive Summary Chapter 1 Introduction Chapter 2 Chemical and Physical Properties and Measurement Chapter 3 Sources, Emissions, Transport, and Deposition Chapter 4 Environmental Concentrations and Pathways to Human Exposure Chapter 5 Models of Human Exposure, Uptake, and Biokinetic Distribution of Lead Chapter 6 Toxicologic Effects of Lead in Laboratory Animals Chapter 7 Epidemiological and Clinical Studies of Lead Effects in Humans Chapter 8 Integrative Synthesis of Human Exposure and Health Risks Chapter 9 Environmental Effects of Lead



### B. METHODS AND PROCEDURES FOR DOCUMENT PREPARATION Responsibilities for developing the revised LeadAQCD will be essentially the same as those used for recent criteria documents, with additional emphasi s being placed on more extensive coordination and collaborative inputs from various participating EPA un its. Briefly, the respective responsibilities are as follows. The Research Triangle Park Division of EPA’s National Center for Environmental Assessment (NCEA-RTP) will have lead responsibility for prepar ation of the updated Lead AQCD. The Director of NCEA-RTP has appointed a project manager and t eam with responsibility for developing the present project work plan for preparation of the document. Development of the plan has been facilitated by input from other EPA program and policy office staff among those listed on the EPA Lead Criteria Work Group (see Appendix B). This resulting draft project plan is being made available for CASAC and public review and will then be revised, as appropriate. It will also be further updated, as appropriate, to reflect any major future changes and/or progress in its implementation. A literature search has been ongoing to collect re ferences on the health and ecological effects of lead. Additional literature searches are also underwayfor other respective areas to be covered in the criteria document; and NCEA-RTP has developed aninformation base to access the references and provide quality assurance and quality control functions . Specific chapter or section authors are being selected on the basis of their expertise in the subject areas and their familiarity with the relevant literature.January 2005 DRAFT – DO NOT QUOTE OR CITE 16 Both EPA and non-EPA scientific experts will be involve d in this effort. The main focus of the revised criteria document will be on evaluation and interpretation of data that deal with the effects of airborne lead on human health and welfare. One or more p eer consultation workshops will be convened to discuss draft criteria document chapters and will focus on th e selection of studies included in the chapters, the potential need for additional information to be added to the chapters, and the quality of the summarization and interpretation of the literature. The respective authors of the draft chapters will revise them on the basis of the workshop discussions. After resolution of outstanding issues and comments derived from the workshops, NCEA-RTP will release the First External Review Draft of the revised Lead AQCD for public comment and CASAC review. Then, revisions will be made on the basis of the public comments and CASAC review. EPA expects that it will be necessary to make a Second External Review Draft available for further CASAC and public review befo re EPA completes and releases the final version of the revised Lead AQCD. Preparation of an update d Lead Staff Paper, drawing upon key findings and conclusions from the Lead AQCD and other related e xposure/risk analyses, will be carried out by EPA’s Office of Air Quality Planning and Standards (OAQPS).


### C. PERSONNEL Dr. Robert W. Elias will serve as the NCEA -RTP project manager responsible for overall coordination of the Lead AQCD preparation effort. Drs. Lester D. Grant and J. Michael Davis will provide overall technical guidance for the health e ffects aspects and Dr. Timothy Lewis for the ecological effects aspects of the document. Other NCEA-RTP project team members who are to provide overall coordination and technical inputs for individual chapte rs are as follows: Dr. Joseph Pinto for the chapter on lead chemistry and measurement methodologies; Dr. Robert Elias, Dr. Joseph Pinto, Ms. Beverly Comfort, and Mr. William Ewald for the chapter on e nvironmental concentrations, patterns, and potential exposures; Dr. Robert Elias for the chapter on lead biokinetic modeling; Drs. Lori White, James Brown, Srikanth Nadadur, and J. Michael Davis for the chap ter materials dealing with toxicological effects in laboratory animals and humans; Drs. Dennis Kotchm ar and Ji Young Kim for review and evaluation of epidemiological studies; and Dr. Timothy Lewis for the chapter on environmental effects. Additional technical assistance on air quality, health effects, and ecological effects will be obtained from EPA scientists in EPA’s National Exposure Research Labor atory (NERL), National Health and Environmental Effects Research Laboratory (NHEERL), and the Office of Air Quality Planning and Standards (OAQPS), as appropriate and needed. As needed, sci entific expertise will also be obtained from outside EPA, utilizing contractual arrangements with non-EPA experts. Members of NCEA-RTP’s project team and other EPA and non-EPA personnel expected to contribute to the document are listed in Appendix C; examples of the pool of experts that EPA expects to tap to assist in development of the Lead AQCD asJanuary 2005 DRAFT – DO NOT QUOTE OR CITE 17 potential authors or contributors of written materials or serving in peer consultative or reviewer roles for review of workshop draft or external reviews dr aft materials are also listed in Appendix C.



### D. APPROACH Discussions will be held between NCEA/RTP sta ff and EPA workgroup members to help identify key issues and approaches to addressing them. Non-EPA experts will also be consulted to help identify and refine key issues to be addressed and pertinent ne w literature to be considered. Discussions will also be held with the authors at the initial stages of document development to acquaint them with detailed guidelines and specifications. Subsequent meeti ngs with authors may be conducted to facilitate continuity within and between chapters. Periodic coor dination meetings will be he ld to facilitate flow of information on document preparation progress, to obt ain feedback on evolving draft materials, and to determine any needed modifications in planned actions. The authors will be provided copies of the previous 1986 Lead AQCD/Addendum and the 1990 Supplement (U.S. Environmental Protection Agency , 1986). New sections for the updated document will each first summarize key findings and conclusions from those prior document materials, including reference to “key” studies. Once this background info rmation is presented, the remainder of the given section will be updated with discussion and interpreta tive evaluation of the newer literature. In cases where no new information is available, the summari zation of key findings from the previous criteria document will suffice. The primary focus in the main Lead AQCD chapters will be on interpretive evaluation of the most pertinent evidence with refe rence being made to more descriptive summarization of details of particular studies provided in separat e annexes to be appended to the main Lead AQCD. A list of references published since the last review of lead criteria (mainly after completion of the 1986 Lead AQCD/Addendum and 1990 Supplement) will be made available to the authors. The references will be selected from information data base searches conducted by EPA and from any materials submitted in response to the November 2004 call for in formation. Hard copies of these references will be supplied upon request. Additional references may need to be added to the list (e.g., missed or recently published papers or “in press” publications). As an aid in selecting pertinent new literature, the authors will also be provided with a summary of issues that n eed to be addressed in the preparation of the revised Lead AQCD. These will include issues identified byauthors and reviewers of the previous lead document materials, raised in public discussions , workshops, or CASAC comments received by EPA and/or raised via interactions involving EPA Lead Wo rkgroup members. The list of issues may be further augmented in the course of preparation or review of draft materials for the revised Lead AQCD.January 2005 DRAFT – DO NOT QUOTE OR CITE 18 

### E. PUBLIC AND SCIENTIFIC REVIEW 1. Review and Revision of Consultative Review Workshop Draft When working drafts of the main chapters (o ther than the Executive Summary) of the document have been completed by the authors, one or more workshops will be convened by the NCEA-RTP Project Team. The workshops will include the document au thors, EPA Work Group participants, and external reviewers chosen on the basis of scientific expertise within specific areas covered. The workshops will be open to the public, as announced in a Federal Register Notice.


### 2. Public Review of External Review Drafts After the workshop consultative review process is completed, the authors, contributing reviewers, and NCEA-RTP Project Team will resolve how to address comments received and will revise the draft chapters in preparation for their inclusion in the Fi rst External Review Draft (ERD) of the Lead AQCD. After clearance by the U.S. EPA, the draft document will be released for public comment as announced in a Federal Register Notice. Electronic and printed copies of the ERD will be made available for review during a specified time period, usually of 60 to 90 days; written comments are solicited during this time. A similar procedure will be followed for public and CASAC review of a Second External Review Draft that EPA expects to be necessary before completion of the Final Lead AQCD. 

### 3. Review by Clean Air Scientific Advisory Committee At the time the First External Review Draft is released to the public, that draft document will also be sent to the Clean Air Scientific Advisory Co mmittee (CASAC) of EPA’s Science Advisory Board (SAB). CASAC members and consultants (see Appe ndix D) will review the draft document and discuss their comments in a public meeting announced in the Federal Register. At the meeting, the NCEA-RTP Project Team plans to present an overview of the mainfeatures of the document, a summary of key issues raised by public comments received on the document, and the charge to the committee, as well as being prepared to discuss proposed revisions, if indicated. Based on CASAC’s past practice, EPA expects that key CASAC advice and recommendations for revisi on of the document will be summarized by the CASAC Chair in a letter to the EPA Administrator. EPA will take into account any such recommendations, as well as CASAC and public comments at the meeting and any written comments received, in revising the draft Lead AQCD. As noted earlier, EPA expects that it will be necessary to prepare a Second External Review Draft for further CASAC review and public comment. After appropriate revision, the final document will be ma de available on an EPA website and subsequently printed, with its public availability be ing announced in the Federal Register.January 2005 DRAFT – DO NOT QUOTE OR CITE 19 

# References Federal Register. (2004) Air quality Criteria Document for Lead: Call for Information. F. R. (November 9) 69: 64926-64928. Federal Register. (1979) National primary and secondary ambient air quality standards: revisions to the National Ambient Air Quality Standards for lead. F. R. (February 8) 44: 8202-8237. 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 nos. EPA/600/8-83/028A-F. Available from NTIS, Springfield, VA; PB87-142949. U.S. Environmental Protection Agency. (1990) Summary of selected new information on effects of lead on health and supplement to 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/600/8-89. Available from NTIS, Springfield, VA; PB92-235670. U.S. Environmental Protection Agency. (2000) Science policy council peer review handbook. 2 nded. Washington, DC: Science Policy C ouncil; report; EPA no. EPA-100-B-00-001.January 2005 DRAFT – DO NOT QUOTE OR CITE A-1 

### APPENDIX A PROPOSED CONTENTS OF REVISED AIR QUALITY CRITERIA FOR LEAD Page LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LIST OF FIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AUTHORS, CONTRIBUTORS, AND REVIEWERS

......................................... EXECUTIVE SUMMARY AND CONCLUSIONS

........................................... 1. INTRODUCTION

................................................................. 1.1 LEGISLATIVE BACKGROUND

............................................... 1.2 REGULATORY BACKGROUND

.............................................. 1.3 DOCUMENT PREPARATION AND REVIEW PROCESS

........................... 1.4 ORGANIZATION AND CONTENT OF THE DOCUMENT

......................... 2. CHEMISTRY/PHYSICAL PROPERTIES OF LEAD AND MEASUREMENT METHODS

...... 2.1 GENERAL CHEMISTRY OF LEAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 ORGANOMETALLIC CHEMISTRY OF LEAD

................................... 2.3 STABLE ISOTOPE METHODOLOGIES

........................................ 2.4 CONTAMINATION CONTROL METHODS

..................................... 2.5 AIR SAMPLING MEASUREMENT/METHODOLOGIES

........................... 2.6 PARTICLE DEPOSITION MEASUREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.7 DUST SAMPLING METHODS FOR HUMAN EXPOSURE

......................... 2.8 BIOLOGICAL TISSUE MEASUREMENT METHODS

............................. 3. SOURCES, EMISSIONS, TRANSPORT, AND DEPOSITION

............................. 3.1 SOURCES AND EMISSIONS OF ATMOSPHERIC LEAD

.......................... 3.2 ATMOSPHERIC TRANSPORT AND DEPOSITION OF LEAD

...................... 3.3 OTHER SOURCES OF LEAD IN DUST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4. ENVIRONMENTAL CONCENTRATIONS AND PATHWAYS TO HUMAN EXPOSURE

..... 4.1 LEAD IN INHALED AIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 LEAD IN INGESTED DUST

.................................................. 4.3 LEAD IN FOOD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4 LEAD IN DRINKING WATER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 OTHER MISCELLANEOUS EXPOSURE PATHWAYS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5. MODELS OF HUMAN EXPOSURE THAT PREDICT TISSUE DISTRIBUTION OF LEAD

..... 5.1 HISTORIC LEAD MODELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2 INTEGRATIVE EXPOSURE UPTAKE BIOKINETIC (IEUBK) MODEL FOR LEAD IN CHILDREN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3 ALL AGES LEAD MODEL (AALM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4 OTHER MODELING APPROACHES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6. TOXICOLOGICAL EFFECTS OF LEAD IN LABORATORY ANIMALS

.................... 6.1 INTRODUCTION

........................................................... 6.2 EFFECTS ON HEME SYNTHESIS

............................................. 6.3 NEUROLOGICAL/NEUROBEHAVIORAL EFFECTS

.............................. 6.4 REPRODUCTIVE AND DEVELOPMENTAL EFFECTS

............................January 2005 DRAFT – DO NOT QUOTE OR CITE A-2 

### PROPOSED CONTENTS (cont’d) Page 6.5 CARDIOVASCULAR EFFECTS

............................................... 6.6 GENOTOXIC/CARCINOGENIC EFFECTS

...................................... 6.7 SUMMARY AND CONCLUSIONS

............................................. REFERENCES

................................................................... 7. EPIDEMIOLOGIC STUDIES OF AMBIENT LEAD EXPOSURE EFFECTS

.................. 7.1 INTRODUCTION

........................................................... 7.2 EFFECTS OF SHORT-TERM AMBIENT LEAD EXPOSURE 7.3 EFFECTS OF LONG-TERM AMBIENT LEAD EXPOSURE

......................... 7.4 SUMMARY AND CONCLUSIONS

............................................. REFERENCES

................................................................... 8. INTEGRATIVE SYNTHESIS OF HUMAN LEAD EXPOSURE PATHWAYS AND HEALTH RISKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.1 INTRODUCTION

........................................................... 8.2 SOURCES, CONCENTRATIONS, AND EXPOSURE PATHWAYS

................... 8.3 EVALUATION OF HEALTH RISKS FROM SHORT-TERM OR EPISODIC LEAD EXPOSURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3.1 Health Effects in the General Human Population

............................. 8.3.2 Health Effects in Susceptible Population Groups

............................. 8.4 HEALTH RISKS FROM LONG-TERM LEAD EXPOSURE

......................... 8.4.1 Effects Associated With Chronic Exposures in Human Populations

.............. 8.4.2 Extrapolation of Effects Observed in Laboratory Animals to Human Populations

.................................................... 8.5 SUMMARY OF KEY FINDINGS AND CONCLUSIONS

........................... REFERENCES

................................................................... 9. ENVIRONMENTAL EFFECTS OF LEAD

............................................. 9.1 TERRESTRIAL ECOSYSTEMS

................................................ 9.1.1 Introduction

.......................................................... 9.1.2 Methodologies Used in Terrestrial Ecosystems Research

....................... 9.1.3 Species Response/Mode of Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.1.4 Factors that Modify Organisms Response to Lead . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.1.5 Exposure/Response of Terrestrial Species

.................................. 9.1.6 Effects of Lead on Natural Terrestrial Ecosystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.1.7 Economic Effects of Lead on Agriculture, Forestry, and other Terrestrial Ecosystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.2 AQUATIC ECOSYSTEMS

.................................................... 9.2.1 Introduction

.......................................................... 9.2.2 Methodologies Used in Aquatic Ecosystems Research

......................... 9.2.3 Species Response/Mode of Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.2.4 Factors that Modify Organisms Response to Lead . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.2.5 Exposure/Response of Aquatic Species

.................................... 9.2.6 Effects of Lead on Natural Aquatic Ecosystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.2.7 Economic Effects of Lead on Aquaculture, Shellfishery, and Fishery Systems

......January 2005 DRAFT – DO NOT QUOTE OR CITE A-3 

### PROPOSED CONTENTS (cont’d) Page 9.3 EFFECTS OF LEAD ON NONBIOLOGICAL MATERIALS

......................... 9.4 EFFECTS OF LEAD ON GLOBAL CLIMATE CHANGE PROCESSES

................ 9.5 SUMMARY AND CONCLUSIONS

............................................. REFERENCES

.............................................................. APPENDIX: GLOSSARY OF TERMS AND SYMBOLS

................................January 2005 DRAFT – DO NOT QUOTE OR CITE B-1 

### APPENDIX B EPA WORK GROUP FOR AIR QUALITY CRITERIA FOR LEAD Dr. William K. Boyes Toxicology National Health and Environmental Effects Research Laboratory (B-105-05) U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Ms. Beverly M. Comfort Indoor air quality National Center for Environmental Assessment (B-243-01) U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Dr. J. Michael Davis Toxicology National Center for Environmental Assessment (B-243-01) U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Dr. Robin L. Dennis Atmospheric modeling National Exposure Research Laboratory (E-243-01) U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Mr. Ronald Evans Economic assessment Office of Air Quality Planning and St andards (C-339-01) consultation U.S. Environmental Protection Agency Research Triangle Park, N.C. 27711 Mr. William G. Ewald Environmental National Center for Environmental Assessment (B-243-01) concentrations U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Mr. Tyler Fox Atmospheric modeling Office of Air Quality Planning and St andards (D-243-01) consultation U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Dr. Mary E. Gilbert Toxicology National Health and Environmental Effects Research Laboratory (B-105-05) U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Dr. Ian Gilmour Immunotoxicology National Health and Environmental Effects Research Laboratory (MD-92) U.S. Environmental Protection Agency Research Triangle Park, NC 27711January 2005 DRAFT – DO NOT QUOTE OR CITE B-2 

### EPA WORK GROUP (cont’d) Gerald Gleason Consultation Office of General Counsel (2344A) U.S. Environmental Protection Agency Washington, DC 20460 Dr. Lester D. Grant, Director Executive and National Center for Environmental Assessment (B-243-01) technical oversight U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Dr. Sharon Harper Analytical methods National Exposure Research Laboratory (D-205-5) Exposure aspects U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Mr. James B. Hemby Air quality Office of Air Quality Planning and St andards (C-304-01) consultation U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Dr. Brooke Hemming Atmospheric science National Center for Environmental Assessment (B-243-01) U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Dr. Lee Hofmann Soil/Dust Pb Office of Solid Waste and Emergency Response consultation Office of Solid Waste (5103-T) U.S. Environmental Protection Agency EPA West Building 1200 Pennsylvania Avenue, N.W. Washington, DC 20460 Dr. Ji Young Kim Epidemiology National Center for Environmental Assessment (B-243-01) U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Dr. Dennis Kotchmar Epidemiology National Center for Environmental Assessment (B-243-01) U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Dr. Charles W. Lewis Source apportionment National Exposure Research Laboratory (E-205-03) U.S. Environmental Protection Agency Research Triangle Park, NC 27711January 2005 DRAFT – DO NOT QUOTE OR CITE B-3 

### EPA WORK GROUP (cont’d) Dr. Timothy E. Lewis Terrestrial and aquatic National Center for Environmental Assessment (B-243-01) ecosystem effects U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Dr. Deborah J. Luecken Atmospheric chemistry National Exposure Research Laboratory (E-205-02) U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Dr. Deborah Mangis Ecosystems; Exposure National Exposure Research Laboratory (D-305-01) U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Dr. Karen M. Martin Consultation Office of Air Quality Planning and Standards (C-539-01) U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Mr. Thomas R. McCurdy Exposure; National Exposure Research Laboratory (E-205-02) Activity patterns U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Mr. David C. Misenheimer Air emissions Office of Air Quality Planning and Standards (D-205-01) consultation U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Dr. Srikanth Nadadur Toxicology National Center for Environmental Assessment (B-243-01) U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Dr. Lucas Neas Epidemiology; National Health and Environmental Children’s health Effects Research Laboratory (MD-58) U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Ms. Sharon V. Nizich Air quality/trends Office of Air Quality Planning and St andards (C-339-02) consultation U.S. Environmental Protection Agency Research Triangle Park, NC 27711January 2005 DRAFT – DO NOT QUOTE OR CITE B-4 

### EPA WORK GROUP (cont’d) Dr. Edward Ohanian Water Pb consultation Office of Water (4304-T) U.S. Environmental Protection Agency EPA West Building 1200 Pennsylvania Avenue, N.W. Washington, DC 20460 Dr. David Olszyk Crops National Health and Environmental Effects Research Laboratory U.S. Environmental Protection Agency 200 S.W. 35th Street Corvallis, OR 97333 David Orlin Consultation Air and Radiation Office of General Counsel (2344A) U.S. Environmental Protection Agency Washington, DC 20460 Dr. Zackary Pekar Exposure/dosimetry Office of Air Quality and Standards (6-339-01) consultation U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Dr. Joseph P. Pinto Air chemistry; National Center for Environmental Assessment (B-243-01) Global effects U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Mr. Harvey M. Richmond Exposure modeling Office of Air Quality Planning and St andards (C-539-01) consultation U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Dr. Mary Ross Human health Office of Air Quality Planning and St andards (C-539-01) consultation U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Mr. William E. Russo Consultation National Health and Environmental Effects Research Laboratory (B-305-02) U.S. Environmental Protection Agency Research Triangle Park, NC 27711January 2005 DRAFT – DO NOT QUOTE OR CITE B-5 

### EPA WORK GROUP (cont’d)
Ms. Victoria A. Sandiford Ecosystems Office of Air Quality Planning and St andards (C-539-01) consultation U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Mr. Kenneth L. Schere Atmospheric modeling National Exposure Research Laboratory (E-243-03) U.S. Environmental Protection Agency Research Triangle Park, NC 27711 Dr. Dave Topping Pb-based paint Office of Prevention, Pesticides, and Toxic Substances (7404-T) consultation U.S. Environmental Protection Agency EPA West Building 1200 Pennsylvania Avenue, N.W. Washington, DC 20460January 2005 DRAFT – DO NOT QUOTE OR CITE C-1 

### APPENDIX C NCEA-RTP PROJECT TEAM AND OTHER TECHNICAL CONSULTANTS NCEA-RTP Project Team Scientific Staff Dr. James Brown — Health Scientist, National Center for Environmental Assessment (B-243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 Ms. Beverly M. Comfort— Health Scientist, National Center for Environmental Assessment

(B-243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 Dr. J. Michael Davis — Senior Health Science Advisor, National Center for Environmental Assessment

(B-243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 Dr. Robert W. Elias — Senior Health Scientist, Nationa l Center for Environmental Assessment

(B-243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 Mr. William G. Ewald — Health Scientist, National Center for Environmental Assessment (B-243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 Dr. Brooke Hemming — Atmospheric Scientist, National Center for Environmental Assessment

(B-243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 Dr. Ji Young Kim — Epidemiologist, National Center for Environmental Assessment (B-243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 Dr. Timothy E. Lewis — Ecologist, National Center for Environmental Assessment (B-243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 Dr. Shrikanth Nadadur— Health Scientist, National Center for Environmental Assessment (B-243 01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 Dr. Joseph P. Pinto — Physical Scientist, National Center for Environmental Assessment (B-243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 Dr. Lori White — Health Scientist, National Center for Environmental Assessment

(B-243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 Technical Support Staff Mr. Douglas B. Fennell— Technical Information Specialist, National Center for Environmental

Assessment (B-243-01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 Ms. Emily R. Lee — Management Analyst, National Center for Environmental Assessment (B-243-01), U.S. Environmental Protection Agency, Research Triangle Park,January 2005 DRAFT – DO NOT QUOTE OR CITE C-2 

### NCEA-RTP PROJECT TEAM AND OTHER TECHNICAL CONSULTANTS (cont’d)

Technical Support Staff (cont’d) Ms. Diane H. Ray— Program Specialist, National Center for Environmental Assessment (B-243-01),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 Ms. Donna Wicker — Management Analyst, National Center for Environmental Assessment (B-243-

01), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 Other EPA Contributors Dr. William K. Boyes — National Health and Environmental Effects Research Laboratory (B-105-05),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 Dr. Ian Gilmour— National Health and Environmental Effects Research Laboratory (B-143-04),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 Dr. Mary E. Gilbert— National Health and Environmental Effects Research Laboratory (B-105-05),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 Dr. Charles W. Lewis — National Exposure Research Laboratory (E-205-03), U.S. Environmental

Protection Agency, Research Triangle Park, NC 27711 Dr. Sharon Harper — National Exposure Research Laboratory (D-205-05), U.S. Environmental

Protection Agency, Research Triangle Park, NC 27711 Dr. Lucas Neas — National Health and Environmental Effects Research Laboratory (MD-82),

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 Dr. David Olszyk — National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, 200 SW 35th Street, Corvallis, OR 97333 Dr. MaryJane K. Selgrade — National Health and Environmental Effects Research Laboratory

(B-143-04), U.S. Environmental Protection Agency, Research Triangle Park, NC 277111 This list of non-EPA scientists is proposed on the basis of published, peer-review ed scientific publications on topic areas that are likely to be included in the revised criteria document or on the basis of previous involvement as an author, contributor, or reviewer of the 1986 Lead AQCD/Addendum. Contractual agreements for professional services would be the likely mechanism for obtaining their contributions to the revised Air Quality Crite ria Document for Lead and/or their participation in workshop s. January 2005 DRAFT – DO NOT QUOTE OR CITE C-3 

### NCEA-RTP PROJECT TEAM AND OTHER TECHNICAL CONSULTANTS (cont’d) Non-EPA Consultants (Potential Sources 1 ) Dr. Carol Angle — Toxicology/Epidemiology, University of Nebraska Medical Center Dr. Ann Aschengrau — Toxicology/Epidemiology, Boston University Dr. Gerald Audesirk — Toxicology/Epidemiology, University of Colorado Dr. Donald Barltrop — Toxicology/Epidemiology, Westminister Children’s Hospital Dr. Barbara Beck — Health Scientist, Gradient Corp Dr. Mike Bolger — Health Scientist, FDA Mr. Craig Borieko — Environmental Scientist, ILZRO Dr. Robert Bornschein — Toxicology/Epidemiology, University of Cincinnati Dr. Mary Jean Brown — Health Scientist, CDC Dr. Ian Calder — Health Scientist, South Australian Health Commission Dr. Rufus Chaney — Environmental Scientist, USDA Dr. Deborah Cory-Slechta — Toxicology/Epidemiology, Rutgers Dr. Anita Curren — Toxicology/Epidemiology, Westchester County Health Department Dr. Cliff Davidson — Environmental Scientist, Carnegie-Mellon University Dr. Gary Diamond — Statistician, Syracuse Research Corp Dr. Kim Dietrich — Health Scientist, University of Cincinnati Dr. Mark Farfel— Toxicology/Epidemiology, Kennedy-Krieger Institute Dr. Russ Flegal— Environmental Scientist, University of California, Santa Cruz Dr. Bruce Fowler — Toxicology/Epidemiology, University of Maryland Dr. Don Fox — Toxicology/Epidemiology, University of Houston Dr. Tom Goehl— Toxicology/Epidemiology, NIEHSJanuary 2005 DRAFT – DO NOT QUOTE OR CITE C-4 

### NCEA-RTP PROJECT TEAM AND OTHER TECHNICAL CONSULTANTS (cont’d) Non-EPA Consultants (Potential Sources 1 ) (cont’d) Dr. Phil Goodrum — Statistician, Syracuse Research Corporation Dr. Robert Goyer— Toxicology/Epidemiology, Retired, Chapel Hill, NC Dr. Brian Gulson — Health Scientist, Macquarie University, Sidney Australia Dr. Vic Hasselblad — Statistician, Duke University Dr. Derek Hodgson — Toxicology/Epidemiology, University of North Carolina Mr. Dave Jacobs — Environmental Engineer, HUD Dr. Richard Kaufman — Health Scientist, ATSDR Dr. David Koeppe — Texas Tech University Dr. Phil Landrigan — Toxicology/Epidemiology Dr. Bruce Lanphear— Toxicology/Epidemiology, Children’s Hospital Medical Center, Cincinnati, OH Dr. Stephen Lasley— Toxicology/Epidemiology, University of Illinois Dr. Samuel Lestz— Pennsylvania State University Dr. Morton Lippmann — Toxicology/Epidemiology, New York University Medical Center Dr. Ben Liu — Atmospheric Scientist, University of Minnesota Dr. Paul Mushak — Toxicology/Epidemiology, PB Associates, Durham, NC Dr. Herbert Needleman — Toxicology/Epidemiology, Children’s Hospital of Pittsburgh Dr. Jerome Nriagu — Environmental Scientist, University of Michigan Dr. Ellen O’Flaherty— Toxicology/Epidemiology, Retired Dr. Anna Orlova — Toxicology/Epidemiology, John Hopkins School of Hygiene & Public Health Dr. Dan Paschal— Environmental Chemist, CDC Dr. Joel Pounds — Toxicology/Epidemiology, Battelle Pacific Northwest Dr. Michael Rabinowitz— Environmental Scientist, Children’s Hospital Medical Center Dr. Deborah Rice — Toxicology/Epidemiology, State of MaineJanuary 2005 DRAFT – DO NOT QUOTE OR CITE C-5 

### NCEA-RTP PROJECT TEAM AND OTHER TECHNICAL CONSULTANTS (cont’d) Non-EPA Consultants (Potential Sources 1 ) (cont’d)
Dr. John Rosen — Toxicology/Epidemiology, Albert Einstein College of Medicine Dr. Glen Sanderson — Environmental Scientist, Illinois Natural History Survey Dr. Ellen Silbergeld — Toxicology/Epidemiology, University of Maryland Dr. Don Smith — Environmental Scientist, University of California, Santa Cruz Dr. William Smith — Ecologist, Yale University, School of Forestry Dr. Paul Succop — Statistician, University of Cincinnati Medical Center Mr. Ian von Lindern — Environmental Scientist, TerraGraphics Mr. Brian Wilson — Environmental Scientist, ILZRO Dr. Nasser Zawia — Toxicology/Epidemiology, University of Rhode IslandJanuary 2005 DRAFT – DO NOT QUOTE OR CITE D-1 

### APPENDIX D U.S. EPA SCIENCE ADVISORY BOARD CLEAN AIR SCIENTIFIC ADVISORY COMMITTEE MEMBERS Fiscal Year 2005 The Clean Air Scientific Advisory Committee (CASAC) has a statutorily mandated responsibility to review and offer scientific and technical advice to the Administrator on the air quality criteria and regulatory documents that form the basis for the national ambient air quality standards (NAAQS), which currently include standards for lead (Pb), particulate matter (PM), ozone (O 3 ), and other photochemical oxidants, carbon monoxide (CO), nitrogen oxides (NO x ) and sulfur oxides (SO x ). To perform such reviews, in each case the Committee forms a review panel consisting of CASA C members and augmented by selected consultants with expertise in scientific or technical areas pertinent to the given pollutant or pollutant class under review.



### CHAIR Dr. Rogene Henderson Lovelace Respiratory Symposium Lovelace Respiratory Research Institute Albequerque, NM 87185 

### PAST CHAIR Dr. Philip Hopke Robert A. Plane Professor Department of Chemical Engineering Clarkson University Potsdam, NY 13699 

### MEMBERS Dr. Frederick Miller Director of Respiratory Toxicology Research Chemical Industry Institute of Toxicology Research Triangle Park, NC 27709 Mr. Richard Poirot Environmental Analyst Department of Environmental Conservation Vermont Agency of Natural Resources Waterbury, VT 05671 Dr. Frank Speizer Edward Kass Professor of Medicine Channing Laboratory Harvard Medical School Boston, MA 02115January 2005 DRAFT – DO NOT QUOTE OR CITE D-2 

### SCIENCE ADVISORY BOARD (cont’d 

### ) MEMBERS (cont’d) Dr. Ellis B. Cowling University Distinguished Professor North Carolina State University Raleigh NC Dr. James Crapo Chairman, Dept. of Medicine National Jewish Medical and Research Center Denver, CO Dr. Barbara Zielinska Research Professor Atmospheric Sciences Division Desert Research Institute Reno, NV 89512 

### SCIENCE ADVISORY BOARD STAFF Mr. Fred A. Butterfield, III Designated Federal Officer Clean Air Scientific Advisory Committee Science Advisory Board (1400A) US Environmental Protection Agency Washington, DC 20460 Ms. Zisa Lubarov-Walton Management Assistant Science Advisory Board (1400A) US Environmental Protection Agency Washington, DC 20460Office of Research and Development National Center for Environmental Assessment Research Triangle Park, NC 27711 Official Business Penalty for Private Use $300 NCEA-R-1465 January 2005 Please make all necessary changes in the below label, detach copy or copy, and return to the address in the upper left-hand corner. If you do not wish to receive these reports CHECK HERE 

## G ; detach copy or copy, and return to the address in the upper left-hand corner. PRESORTED STANDARD POSTAGE & FEES PAID EPA PERMIT No. G-35