UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
October 23, 2002
EPA-SAB-EC-LTR-03-001
OFFICE OF THE ADMINISTRATOR
SCIENCE ADVISORY BOARD
The Honorable Christine Todd Whitman
Administrator
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Subject: Review of Metals Action Plan; An EPA Science Advisory
Board Report
Dear Governor Whitman:
On September 10-12, 2002, the Metals Assessment Panel of the EPA Science Advisory
Board reviewed the EPA's plans for development of a Framework for Metals Risk Assessment
and a Guidance for Characterization and Ranking of Metals. With this letter, we are submitting
the Panel's review.
In the Metals Action Plan, the EPA has put forward the key scientific issues important for
assessing the hazards and risks of metals in general. The Panel understands that in future
documents, the EPA will put forward approaches for evaluating or ranking the risks and hazards
of metals in specific applications. Accordingly, in this review, the Panel addressed the broad
scientific issues underlying the assessment of metals hazards and risks, and not specific
parameters that might or might not be used in particular applications. The SAB looks forward to
continuing to be involved as this work proceeds from general scientific principles to guidelines
for specific applications.
Overall, the Panel agrees that metals should be assessed differently from organic
pollutants in a number of contexts. The Panel also agrees that the issues of chemical speciation,
bioavailability, bioaccumulation, and toxicity are key issues in assessing the hazards of metals.
However, in developing an overall framework, the Panel recommends that these
scientific issues be considered broadly, with consideration of all the relevant processes, rather
than narrowly considering these issues merely as parameters or fixed values. In particular, the
Panel recommends that:
a) speciation be considered broadly in terms of the environmental chemistry that
determines speciation and transformation under various conditions; that
b) bioaccumulation be considered broadly, as determined by a set of processes that
are related to the processes of bioavailability; and
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c) the temporal characteristics of the risks and hazards of metals be considered not
merely as a persistence parameter, but broadly in terms of the underlying
chemical, biological and physical processes.
These recommendations are consistent with a previous SAB Review of "An Integrated
Approach to Metals in Surface Waters and Sediment" (EPA-SAB-EPEC-00-005), which
recommended that the EPA develop a "conceptual model that incorporates all partitioning phases
and routes of exposure in order to guide the Agency's long-term efforts." By considering the
scientific issues broadly in development of an overall framework, EPA can develop a scientific
foundation to support appropriate simplifications in particular applications.
The Panel commends the EPA for seeking advice on the Action Plan at an early stage.
We look forward to reviewing the Framework and Guidance when they are developed. Please
contact us if we may be of further service.
Sincerely,
/Signed/
Dr. William Glaze, Chair
EPA Science Advisory Board
/Signed/
Dr. Valerie Thomas, Chair
Metals Assessment Panel
EPA Science Advisory Board
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SAB REVIEW OF THE METALS ACTION PLAN
1. EXECUTIVE SUMMARY
The draft Action Plan initiates the development of a Framework for Metals Assessment
and a Guidance for Characterizing and Ranking of Metals (henceforth, the Action Plan,
Framework, and Guidance, respectively). At this stage, the role of the EPA Science Advisory
Board (SAB) review is not to approve or evaluate scientific conclusions, but rather to provide a
preliminary response to the activities proposed in the Action Plan.
The Panel commends the EPA for seeking advice on the Action Plan at an early stage.
Based on the current status of the Action Plan, the Panel has the following comments and
suggestions:
a) The Panel agrees that metals should be assessed differently from organic
pollutants in a number of contexts. Metals are elements and, while they do not
degrade, they undergo complex environmental chemistry. Metals are naturally
occurring; some are essential for living organisms.
b) The Panel agrees that the issues of chemical speciation, bioavailability, including
bioaccumulation, and toxicity are key issues in assessing the hazards of metals,
with the following qualifications:
i) The Panel recommends that metal speciation be considered broadly under
the umbrella of environmental chemistry. Understanding chemical
speciation with regard to the most toxic forms is clearly important to
assessing hazard and risk. But also important to this assessment are
processes occurring at environmental interfaces (including organisms)
and/or in different environmental compartments which regulate the rate of
formation, stability and prevalence of these metal species. These reactions
likewise control the chemical speciation of metals that enhance or restrict
their transport in the environment, and to and within organisms.
ii) The panel recommends that bioaccumulation be considered broadly under
the umbrella of bioavailability. Understanding bioaccumulation is clearly
important. To develop a broader framework for understanding, the
processes determining both bioavailability and bioaccumulation should be
considered as an integrated concept. Bioaccumulation encompasses not
only the net result of the competing processes of chemical uptake and
elimination by an organism, but also the distribution of the chemical
within organisms. Bioaccumulation processes are related to
bioavailability processes, both because bioavailability is a measure of
chemical uptake by an organism, and because the bioaccumulation of a
chemical by one organism may make it bioavailable to another organism.
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iii) The Panel recommends stability and environmental residence time as
more appropriate variables or terms than persistence for characterizing the
temporal dynamics of metals. All metals are persistent. Characteristics
such as stability of the toxic species or the environmental residence time,
and overall environmental chemistry, determine the temporal
characteristics of the hazard.
c) The Panel recommends greater emphasis on the combined effects of metals,
including nutritional and toxicological considerations. The scientific foundation
for such assessments is under development and EPA should begin to think about
these considerations.
d) The Panel recommends that the differences between assessments for ecological
systems and assessments for human health be clarified and highlighted in the
Framework and Guidance. The emphases in human health assessments are often
quite different from those in ecological system assessments. Key differences
include: the focus of the assessment (humans or ecological populations); exposure
pathways; receptors and endpoints; data availability and quality; uncertainty
requirements; metrics, and criteria for defining acceptable risks.
e) The Action Plan is inconsistent and somewhat confusing in its use of the words
hazard and risk. EPA needs broadly and fundamentally to rethink where and how
hazard and risk differ, when it is or is not appropriate to use either, and apply that
perspective consistently throughout the Framework and Guidance documents.
Hazard deals with inherent properties of substances; risk adds the critical
exposure element, which is necessary to accurately gauge safety or danger in a
given use and exposure scenario. A hazard ranking of metals would produce a
different end-result than a risk ranking, as the latter weighs the context of
exposure.
f) In evaluating risk, exposure must be considered. The Panel recommends greater
emphasis on exposure in the Framework. EPA should examine approaches to
incorporate public health, environmental, and ecological system surveillance data
in the metals risk assessment process.
The Panel recommends extensive consultation with the scientific community,
the public, stakeholders, and intended users, including risk assessors in other federal and state
agencies when developing the Framework and Guidance.
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2. INTRODUCTION AND PROCEDURAL HISTORY
In response to a request from EPA, the EPA Science Advisory Board formed a
specialized Metals Assessment Panel to review the draft Metals Action Plan. In doing so, the
staff used the new panel formation process, approved by the SAB's Executive Committee May
8, 2002 and described in EPA Science Advisory Board (SAB) Panel Formation Process:
Immediate Steps to Improve Policies and Procedures - An SAB Commentary
(EPA-SAB-EC-COM-02-003) available at http://www.epa.gov/sab/pdf/ecm02003.pdf.
The Panel met by public conference call meetings on August 8, 15 and 29, 2002. At
those meetings, the Panel heard briefings on Federal ethics rules and regulations, and on the
document to be reviewed; listened to invited presentations from outside experts; provided
opportunities for public comment; and presented and discussed preliminary responses to the
charge questions. Panelists circulated revised responses before the September 10-12, 2002
face-to-face meeting.
In addition to the "Draft Action Plan for the Development of a Framework for Metals
Assessment and Guidance for Characterizing and Ranking Metals" (EPA/630/P-02/003A, June
2002), EPA provided the Panel with public comments on that plan and a number of background
documents. Public commenters also provided written text and documents.
At the face-to-face meeting, the panelists heard an additional briefing from EPA and two
public comments. The chief activity of the Panel was the preparation and approval of its report
for subsequent consideration by the Executive Committee. The Panel approved its report
September 12, 2002. The Executive Committee considered this report at its October 1-2, 2002
meeting.
Each charge question appears below in its entirety followed by the Panel's response.
3. RESPONSE TO THE CHARGE
Charge Question # 1
Please comment on the soundness of the proposed organizing principles suggested by the public
that are reflected in the draft Action Plan for the * ^Framework for Metals Assessment and
Cross-Agency Guidance for Assessing Metals-Related Hazard and Risk." (The proposed
organizing principles, listed in section 1 of the draft Action Plan, include the following:
providing a basis for identifying and prioritizing among metals, metal alloys and other metal
compounds with respect to hazard and risk, use of sound science, use of a tiered approach,
recognition of the influence of bioavailability on toxicity, and initially focus on hazard
assessment as a screening tool.)
The organizing principles suggested in the Action Plan are generally sound and address a
number of issues for inclusion in a long term EPA strategy.
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Specifically, the plan for identifying and prioritizing metals, metalloids, metal alloys,
organo-metallic and other metal compounds (henceforth referred to as metals) is critical with
respect to distinguishing assessment of hazard and risk. This process is important since those
metals of greatest interest to public health or the environment will vary over time. Therefore a
flexible process is needed that can accommodate changing priorities and new science. The Panel
recommends that EPA retain the general tenets common to ecological and human health risk
assessments in the Framework but separate them in the Guidance to delineate specific
differences between ecosystems and human health. Clarification of the scope of both the
Framework and Guidance would be helpful, with respect to which metals are included as well as
a range of other issues.
Development of credible environmental regulations requires the use of sound data and
current state-of-the-art science. These regulations need to take advantage of modern scientific
tools that incorporate mechanistic data. While some of these methods will require validation
with time and experience, inclusion of a narrative commentary on their potential application to
regulatory approaches for metals will enhance the utility of the Framework and Guidance over
time. As some of these newer methods (e.g., biomarkers) are validated, they can be incorporated
into future versions of the Framework. Mechanistic approaches that integrate metal- induced
effects across the molecular, cellular and whole organism levels of biological organization will
reduce uncertainty. Such approaches would enhance the sensitivity of any National Hazard or
Risk Assessments and ultimately lead to a mechanism-based regulatory process. The latter will
add further scientific credibility to any derived regulations. Including mechanistic data in the
discussed tiered approach could also be very useful in interpreting findings and predicting risk in
complex mixture situations such as Superfund sites.
Bioavailability exerts a major influence on bioaccumulation and toxicity. In aqueous
systems, factors such as salinity, complexation with humics and methylation by bacteria are
examples of processes that will influence uptake/toxicity by organisms living in different
environments. In terrestrial environments, complexation of toxic elements with respirable
particles in soil may vary as a function of soil pH, and bacterial populations. Metal binding to
respirable particles may also vary as a function of incineration temperatures. The revised Action
Plan would be strengthened by a more detailed inclusion of such factors beyond those currently
incorporated. The intracellular handling of metals in target cell populations is a topic which is
not addressed in the current Action Plan beyond the paragraph on page 14 in relation to the toxic
potential of metals to aquatic species. The potential role of these compartments as factors
influencing the bioaccumulation of metals in some edible species should be further developed in
the Framework and Guidance.
Finally, the focus on hazard assessment as an initial screening tool could be strengthened
by delineating differences between hazard and risk and consideration of other critical factors.
The Panel strongly recommends that EPA clearly distinguish between hazard and risk
assessments and apply the most appropriate approach in a given situation. Hazard and risk
assessment approaches would be strengthened by inclusion of a number of factors. Aggregate
and cumulative risks as well as metal-metal mixtures must be considered. Dose is only one
factor in assessing hazard/risk. Duration and frequency of exposure are major variables critical
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to chronic low dose exposures. The issue of most appropriate toxic endpoints for a given
organism or toxic element must be addressed. The issue of sensitive sub-populations and species
should be discussed. Developing organisms (e.g., larvae of Crustacea or fetal/newborn
mammals) are recognized as highly sensitive life stages. Susceptibility of geriatric populations
is also of increasing concern and should be considered in these processes as the world population
ages. Nutritional status should also be considered since this factor can influence susceptibility to
metals.
Charge Question #2
Are the issues raised in the Action Plan—chemical speciation, bioavailability, bioaccumulation,
persistence, and toxicity—the major issues of concern for improving EPA's scientific assessments
of the hazards and risks of metals?
Chemical speciation, bioavailability, including bioaccumulation, and toxicity are relevant
scientific issues identified in the Action Plan but the Panel recommends that environmental
chemistry should be an umbrella issue embracing and expanding the issue of chemical
speciation. Understanding chemical speciation with regard to the toxicity is clearly important to
assessing their hazard and risk. But also important to this assessment, are processes occurring at
environmental interfaces (including organisms) and/or in different environmental compartments
which regulate the rate of formation, stability and prevalence of these metal species. These
reactions likewise control the chemical speciation of metals that enhance or restrict their
transport in the environment, and to and within organisms.
The Panel believes that persistence is a problematic scientific issue for assessing metals
hazards and risks. In the case of synthetic organic contaminants, persistence refers to their
environmental stability relative to degradation, thus providing a metric of exposure. As the
Action Plan points out, metals do not degrade so that "persistence" relative to their
environmental fate has little meaning. The Panel suggests that for metals, persistence is
addressed better within the context of environmental chemistry in terms of stability of
chemical species, residence times and attenuation within environmental media.
While bioaccumulation data can be useful for site specific assessment of risk,
bioaccumulation metrics such as BCF/BAF measures can be problematic for assessing generic
metal hazard ranking. In general, bioaccumulation data are less straight forward to evaluate for
hazard and risk assessment due to the essentiality of some metals, the various methods organism
have adapted to regulate and detoxify (and therefore expunge) metals, natural occurrence and the
variation of background metal levels, and the known inverse relationship of metal exposure to
accumulation to living systems to name a few issues. The panel recommends that
bioaccumulation be considered broadly under the umbrella of bioavailability. Understanding
bioaccumulation is clearly important. To develop a broader framework for understanding, the
processes determining both bioavailability and bioaccumulation should be considered as an
integrated concept. Bioaccumulation encompasses not only the net result of the competing
processes of chemical uptake and elimination by an organism, but also the distribution of the
chemical within organisms. Bioaccumulation processes are related to bioavailability processes,
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both because bioavailability is a measure of chemical uptake by an organism, and because the
bioaccumulation of a chemical by one organism may make it bioavailable to another organism.
Considering the scientific issues broadly in the development of the Framework will
provide a more robust basis for determining appropriate simplifications that will be needed for
specific applications.
Charge Question # 3
Has EPA adequately characterized the issues and do the summaries adequately capture the key
scientific uncertainties that will need to be addressed by the Framework and the Guidance?
The Panel agrees that speciation (under the umbrella of environmental chemistry),
bioavailability including bioaccumulation, and toxicity are key scientific issues but that
persistence should not be considered a key issue (Charge Question 2). Have these issues been
adequately characterized in the Action Plan? The Panel reached the following conclusions:
The broader scientific issues of environmental chemistry of metals should be part of the
Framework. In the context of environmental chemistry of metals, additional scientific issues that
were missing include stability, transformation processes (physical, chemical, biological
speciation transformation dynamics), background metal levels, frequency of occurrence and
monitoring, and important transport pathways into the environment and within different media
(air, water, solid). A major concern with respect to uncertainty in speciation and environmental
chemistry issues of metals is the extrapolation of data from model to natural systems to assess
environmental risk. This should be emphasized as well.
The sections on bioavailability and toxicity adequately characterize the basis for
including these as primary scientific topics in the Framework. However, extrapolation from
model systems (e.g., the use of surrogate species) to assess bioavailability and toxicity for
ecological system or human receptors involves uncertainties that need to be addressed.
The issue of persistence was adequately addressed. The Panel believes that persistence is
inherently part of the environmental chemistry of metals and included in the context of species
environmental residence times, transformation rates and the predominance under a specified set
of environmental conditions (e.g., pH, redox conditions, and ligand concentrations). In the case
of metals, persistence may be protective rather than detrimental and this aspect should be
recognized.
The background section illustrates in some instances (e.g., bioaccumulation) that metals
should be treated differently than organics in the context of assessment of risk and hazard. The
Panel concludes that metals, in many contexts, need different criteria for characterizing hazard
compared to organics, and that the Framework should consider this possibility from the outset.
Better supporting information should be provided on the numbered Summary Issues in
the Action Plan. Many of the numbered summary issues (except for those provided in the
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bioaccumulation section) were inadequately characterized and did not follow logically from the
discussion provided. The Panel liked the organization of the Bioaccumulation section in which
supporting information was provided for each numbered summary issue. If other sections had
been similarly structured, the numbered summary issues would have been much more useful to
the Panel. These questions raised in the numbered summary issues should be reconsidered in the
Framework when a more in-depth review of the major scientific issues is undertaken.
Charge Question # 4
Can the SAB suggest priorities within the list of issues based on (a) the potential impact on the
assessment of risk or hazard and (b) the state-of-the-science and the feasibility of developing
guidance in the near term?
Determination of priorities can be done in many ways (e.g., "use-exposure-properties"
approach, or evaluation of rank, based on one or several of the issues - e.g., toxicity,
bioavailability). The Panel can not prioritize the issues presented without a context. Evaluating
the state-of-the-science and providing guidance without context is a fruitless undertaking. Once
the supporting white papers are developed, the state of the science can be evaluated. Available
scientific information varies widely by organism and key issue (environmental chemistry,
bioavailability, toxicity) of interest. Conceptually, a systematic approach to evaluating
information (e.g., developing a matrix) is necessary. A matrix can be generated with key issues
on one axis and organism/trophic level on another. Assessment of the supporting science (little,
some, sufficient) can be used to identify gaps in the science/knowledge base, or areas suitable for
investigation.
Charge Question # 5
Are there specific recommendations for the Framework or for the "Guidance for
Characterization and Ranking of Metals" (including methods and models) for addressing these
issues that are not captured by EPA's Action Plan?
Models and methods - A number of models and methods are available for estimating
speciation, bioavailability, bioaccumulation, and exposure and toxicity. Few were described in
the Action Plan. At this stage in the process it is appropriate not to include specific models.
However, several aspects related to modeling should be made more transparent in the
Framework, including: what data needs exist for modeling or setting criteria, the relative
uncertainties of data and how uncertainty will be addressed.
Clarity on receptors - The Framework discussion should delineate ecological system and
human health risks. The Panel suggests that the Guidance address ecological and human health
issues separately. Although the Panel recognizes that an integrated, human health and ecological
perspective is the desired end-product, there are substantial differences, including the audience
to warrant separate documents. Risks to human and ecological receptors vary widely by metal.
Key differences include: the focus of the assessment (humans or ecological populations);
exposure pathways; receptors and endpoints; data availability and quality; uncertainty
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requirements; metrics (e.g., RfD vs NOEC), and criteria for defining "acceptable risks." Major
issues in the Framework also have different connotations to human health and ecological risk
assessors. For example, in the outline, principles to determine sensitive sub-populations that
receive significant exposure of concern were presented under the heading "Assessment of
Endpoint Selection," (section 2.4). Human health risk assessors tend to interpret endpoint in the
context of toxic conditions (e.g., neurological, reproductive, and developmental effects, etc.) and
not the various receptors in the ecological system. The term "sensitive sub-population" means
sensitive species (i.e. biological sensitivity) to ecological risk assessors, while sensitive
sub-population in human terms can be defined based on a number of parameters (e.g., age,
gender, genotype, exposure strata, etc.).
Surveillance data - The Action Plan briefly mentions natural metal background levels in
the bioavailability section. In most cases, site-specific background levels of metals in
groundwater were discussed. Human biomonitoring provides integrated measures of exposure
and in the case of metals, natural background burdens may be captured in these integrated
measures. Ongoing exposure surveillance programs such as the NHANES/NCEH surveillance
program are intended to establish such population baseline exposure levels. A large number of
metals are included on the list of analytes in the NHANES (1999) study.1 These data may be
used in the context of national risk assessment and ranking when they become available. There
are also a number of extant environmental monitoring data for metals2 but the Action Plan makes
no mention of these resources and their utility in metal risk ranking and assessment. The US
Geological Survey has a program called NASQAN (National Stream Quality Accounting
Network) that measures chemicals including some metals, nutrient ions and pesticides in rivers
across the United States (http://water.usgs.gov/nasqan)3. In the development of the Framework
and Guidance, EPA should examine approaches to incorporate public health, environmental and
ecological system surveillance data.
Metal mixtures — The Action Plan does not address the issue of metal mixtures and the
possible types of interactions (additive, synergistic, antagonistic) among metals. Also,
environmental mixtures should be evaluated in the context of prevailing body burdens (including
body burden of essential metals and dietary intake) in living organisms (Mertz, 1993).
Superfund sites frequently contain elemental mixtures. The Framework and Guidance should
address this issue, even if it is only in a generic way that would allow for more sophisticated
analyses as the science develops. A growing number of investigators and other Federal agencies
such as ATSDR are taking an active interest in this area. This means that in the near future, the
1 http://www.cdc.gov/nceh/dls/nhanes.htm (accessed 4/30/02)
USEPA's (1992) Inventory of Exposure-Related Data Systems Sponsored by Federal Agencies provides
descriptions of databases and contact for other sources of exposure data, with a focus on environmental
concentrations. (EPA/600/R-92/078)
3 Other relevant programs include NOAA's National Status and Trends Program and EPA's EMAP Program
(Environmental Monitoring and Assessment Program).
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database on metal-metal interactions will become more robust and it will be easier to incorporate
new data into a regulatory framework that has already considered this issue. A discussion of
metal mixtures from this perspective will indicate a current awareness and facilitate inclusion of
interaction data as they are published.
CHARGE QUESTION # 6
Please comment on the feasibility of the proposed process for drafting the Framework and the
Guidance. Will the timeline allow for the scientific issues to be adequately addressed? Are the
measures being taken to involve the scientific community and the public adequate?
The Action Plan provides only a superficial description of the Guidance, which
presumably will be designed to provide the criteria for application. Furthermore, the Action Plan
does not address how the Guidance is going to be used by risk assessors. To be useful and
comprehensive, the Framework should present the principles and methods for metals assessment
so that they relate directly to the risk assessor's responsibilities.
The Action Plan provides little information on how the Framework and Guidance are to
be coordinated. Figure 1 of the Action Plan indicates somewhat parallel paths, offset by a few
months, but the specifics of how the two efforts are to be completed are not articulated. The
Panel is concerned that the Framework and Guidance might diverge in content without a
deliberate a priori plan for integration. Writing the Framework to facilitate the preparation of
the Guidance will prove useful and serve as a model for further EPA initiatives.
The schedule laid out in the Action Plan, if the Guidance is adopted on the basis of the
Framework, may require some modification, requiring earlier action on the former rather than
the latter. Even without pursuing integration between the two documents, the schedule appears
to be ambitious. The timeline for developing white papers by the start of Workshop #1
(November 2002) will be difficult to achieve. The succeeding steps should be feasible if the
initial part of the schedule is performed on time.
The proposed steps for involving the public and scientific community are reasonable
although fairly conventional. The panel considered whether novel forms for involving the public
could be undertaken. These might include interactive web-based surveys and communications.
(Weiss, 2001) The Panel recommends extensive outreach in the development of both the
Framework and the Guidance to the scientific community, the public, stakeholders, and to
intended users of the Guidance including risk assessors in other federal and state agencies.
CHARGE QUESTION # 7
Please comment on the outline for the Framework and the description of the Guidance. Is it
clear and all-inclusive?
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Aligning Regulatory Functions with Tiered Risk Assessment
The proposed Framework (Section 1.1.3 "Tiered Approach") relates the tiered approach
for risk assessment to three regulatory functions: National Hazard/Risk Ranking and
Characterization, National Regulatory Assessments, and Site-Specific Assessments. The tiered
approach is a broadly-accepted paradigm which recognizes the value of systematic and
graduated assessments of risk based upon data availability, and needs for accuracy and/or the
reduction of uncertainty. The Action Plan implies that these regulatory functions parallel tiered
risk assessment in terms of these needs. The Panel questions whether the three regulatory
functions consistently follow the same logic and pattern and will always "fit the mold" of tiered
assessment.
Regulatory functions such as the three described in the proposed Framework are designed
and implemented to comply with specific statutory requirements dictated by law. They may or
may not follow sound principles or processes for conducting risk assessment. Legislative or
judicial mandates may require the collection of certain effects or exposure data that are not
necessary for risk assessment. Conversely, legal requirements for data collection may be
inadequate to enable thorough risk assessment. The Guidance should not, for example, imply:
that National Regulatory Assessments always require less data and precision than Site-Specific
assessments; that screening level assessments cannot be performed on a site (indeed, soil
screening levels are designed to do just that); or that National Hazard Characterizations can be
conducted on the basis of screening level risk assessment using data readily at hand.
Distinguishing Between Hazard and Risk
The Action Plan is inconsistent and somewhat confusing in its use of the words hazard
and risk. The phrase "hazard and risk" are used repeatedly throughout the document, as if
synonymous and interchangeable. Hazard deals with inherent properties of substances; risk adds
the critical exposure element that is necessary to accurately gauge safety or danger in a given use
and exposure scenario. A hazard ranking of metals would produce a different end-result as a risk
ranking, than the latter weighs the context of exposure. EPA needs to broadly and
fundamentally rethink where and how hazard and risk differ, when it is, or is not, appropriate to
use either, and apply that perspective consistently throughout the Framework and Guidance
documents.
In the Framework, the key process of Risk Characterization particularly needs to be
further developed. Under Section 4.0 (p. 37), "Characterization of Exposure and Effects", there
is no mention of when and how effects and exposure data for metals can be integrated into the
fundamental metric of risk. Relevant questions include: How should risk be calculated for
metals? When are quotient methods acceptable versus a distributional (e.g., probabilistic)
analysis of risk? How does one treat background or reference levels of metals in the
environment, unique from synthetic organic chemicals? How can the risks of both metal
deficiencies as well as intoxication be recognized, as indicated by the U-shaped dose-response
curve of essential metals?
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The Action Plan also distorts hazard and risk in the description of the Guidance, which
would seem to primarily relate to hazard ranking. If so, it should not refer to "risk
prioritization", which is best accomplished by procedures which weigh both effects and exposure
information (e.g., comparative risk analysis). Generic and simplistic ranking of metals (e.g., Hg,
Pb, Cd, Cu, Zn) without consideration of exposure, may compromise the risk assessment process
and could lead to regulations and practices which are scientifically unsound, if not dangerous.
For example, a broadly-discharged or poorly managed substance with relatively low toxicity
may pose greater risk than a highly toxic but well-managed substance. If a risk ranking exercise
is attempted, consideration should be given to factors such as: uses of metals, the availability of
surveillance data, and the context of exposure (e.g., extraction of minerals; refining; chemical
processing and manufacturing; industrial uses as catalysts, etc.; consumer uses, by product
sectors; agricultural uses).
Guidance for Characterization and Ranking of Metals
There is simply too little information offered in the description of this Guidance (i.e.,
four paragraphs on p. 38) to ascertain whether it will be "clear and all-inclusive."
CHARGE QUESTION # 8
Are there any additional actions, beyond those proposed in the Action Plan that could improve
EPA's scientific assessments of the hazard and risks of metals?
EPA's scientific assessments would be improved by an evaluation of how impaired
function in an organ system, organism or ecological system will predispose that system, and
other systems, to adverse effects of metals. In human populations, the very old and the very
young as well as those with impaired immune systems are examined for that reason. Infants rely
on immature, inadequate mechanisms to eliminate chemicals with toxic properties. For example,
high nitrate levels in drinking water can pose a special risk for infants because their low stomach
acidity facilitates bacterial conversion of nitrate into nitrite and leads to methemoglobinemia. In
ecological systems, elevated levels of acids, ozone or other toxins, or temperature or moisture
stress, can predispose the system to adverse effects of metals. Whether the system is a human
being suffering malnutrition or disease, or an ecological system suffering effects of air pollution,
global warming or insect infestation, it is probable that effects of metals would be exacerbated
by the predisposing agent. The amount of exacerbation and the circumstances facilitating
adverse effects of metals are poorly known.
In stressed systems such as those in proximity to a smelter, exposure to metals can come
from air, water and soil simultaneously. Multiple sources and cumulative and aggregate
exposure should be considered in the Framework. The Panel believes that airborne exposures to
metal particulates should receive more attention in the Framework and Guidance than currently
contemplated. For example, fine metal dust inhaled by susceptible individuals enhances
sensitization to common allergens (Peden, 1997; Carter et al., 1997; Lambert et al., 2000). Such
adjuvant effects, which may have both positive and negative consequences, are exemplified by
aluminum. In addition, recent findings indicate transport into the brain by ultrafine particles,
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including metals, underline the role of inhalation exposures in evaluating total exposure
(Oberdorster and Utell, 2002)
Finally, since some metals are plant and human essential trace elements, both too little
and too much exposure present risks. The Framework should carefully note the non-monotonic
dose-response functions characteristic of many metals.
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airway epithelial cells after exposure to an air pollution particle is metal-dependent. Toxicol.
Appl. Pharmacol. 146:180-118.
Lambert, A.L. Dong, W., Belgrade, M.J., and M.I. Gilmont. 2000. Enhanced allergic
sensitization of residual oil fly ash particles is enhanced by soluble metal constituents.
Toxicology and Applied Pharmacology 165:84-93.
Mertz, W. 1993. Essential Trace Metals: New Definitions Based on New Paradigms. Nutrition
Reviews 51(10):287-295.
Oberdorster G. and MJ. Utell. 2002. Editorial: mathematical modeling in environmental health.
Environ. Health Perspect. 110:A440-1.
Peden, D.B. 1997. Mechanisms of pollution-induced airway disease in vivo studies. Allergy
52:37-44.
Weiss, B. 2001. A Web-Based Survey Method for Evaluating Different Components of
Uncertainty in Relative Health Risk Judgements. Neurotoxicology 22:707-721.
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U.S. Environmental Protection Agency
Science Advisory Board
Executive Committee
CHAIR
Dr. William Glaze, Professor and Director, Carolina Engineering Program, Department of
Environmental and Engineering, School of Public Health, University of North Carolina, Chapel
Hill, NC
SAB MEMBERS
Dr. Henry Anderson, Chief Medical Officer, Division of Public Health, Wisconsin Division of
Public Health, Madison, WI
Also Member: Environmental Health Committee
Integrated Human Exposure Committee
Dr. Trudy Cameron, Raymond F. Mikesell Professor of Environmental and Resource
Economics, Department of Economics, University of Oregon, Eugene, OR
Also Member: Advisory Council on Clean Air Compliance Analysis
Dr. Kenneth Cummins, Senior Advisory Scientist, California Cooperative Fishery Research
Unit, Humboldt State University, Arcata, CA
Dr. Domenico Grasso, Rosemary Bradford Hewlett Professor and Chair, Picker Engineering
Program, Smith College, Northampton, MA
Also Member: Environmental Engineering Committee
Dr. Linda Greer, Senior Scientist, Natural Resources Defense Council, Washington, DC
Dr. Philip Hopke, Bayard D. Clarkson Distinguished Professor, Department of Chemical
Engineering, Clarkson University, Potsdam, NY
Also Member: Clean Air Scientific Advisory Committee
Research Strategies Advisory Committee
Dr. Janet A. Johnson, Senior Technical Advisor, Shepherd Miller, Inc, Fort Collins, CO
Also Member: Radiation Advisory Committee
Dr. Roger E. Kasperson, Executive Director, Stockholm Environment Institute, Stockholm,,
Sweden
Dr. Raymond C. Loehr, Hussein M. Alharthy Centennial Chair and Professor, Department of
Civil Engineering, The University of Texas at Austin, Austin, TX
Also Member: Research Strategies Advisory Committee
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Dr. M. Granger Morgan, Head, Department of Engineering and Public Policy, Carnegie
Mellon University, Pittsburgh, PA
Dr. Ken Sexton, Professor, Department of Environment and Occupational Health, University of
Minnesota, Minneapolis, MN
Also Member: Integrated Human Exposure Committee
Dr. William H. Smith, C.R. Musser Professor Emeritus of Forest Biology, Yale University,
Center Harbor, NH
Dr. Robert Stavins, Albert Pratt Professor of Business and Government, Environment and
Natural Resources Program, John F. Kennedy School of Government, Harvard University,
Cambridge, MA
Also Member: Environmental Economics Advisory Committee
Dr. R. Rhodes Trussell, Senior Vice President, Montgomery Watson Harza Engineering,
Pasadena, CA
Also Member: Drinking Water Committee
Dr. Terry F. Young, Senior Consulting Scientist, Environmental Defense, Oakland, CA
Also Member: Ecological Processes and Effects Committee
SCIENCE ADVISORY BOARD STAFF
Mr. A. Robert Flaak, Designated Federal Officer, US EPA Science Advisory Board, 1200
Pennsylvania Avenue, NW, Washington, DC
Ms Betty Fortune, Office Assistant, US EPA Science Advisory Board, 1200 Pennsylvania
Avenue, NW, Washington, DC
Ms. Diana Pozun, Program Specialist, US EPA Science Advisory Board, 1200 Pennsylvania
Avenue, NW, Washington, DC
Rosters-2
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U.S. Environmental Protection Agency
Science Advisory Board
Metals Assessment Panel*
CHAIR
Dr. Valerie Thomas, Princeton University, Princeton, NJ
Also Member: Environmental Engineering Committee
OTHER SAB MEMBERS
Dr. Charles A. Pittinger, Cadmus Group Inc, Cincinnati, OH
Also Member: Ecological Processes and Effects Committee
CONSULTANTS
Dr. Bruce Fowler, Agency for Toxic Substances and Diseases Registry, Atlanta, GA
Dr. Andrew Friedland, Dartmouth College, Hanover, NH
Dr. Kim Hayes, University of Michigan, Ann Arbor, MI
Dr. Mary Kay O'Rourke, University of Arizona, Tucson, AZ
Dr. Nga L. Tran, Exponent, Washington, DC
Dr. Bernard Weiss, University of Rochester Medical Center, Rochester, NY
Dr. Herbert L. Windom, Skidaway Institute of Oceanography, Savannah, GA
SCIENCE ADVISORY BOARD STAFF
Ms. Kathleen White, Designated Federal Officer, US EPA Science Advisory Board, 1200
Pennsylvania Avenue, NW, Washington, DC
Ms. Zisa Lubarov-Walton, Management Assistant, US EPA Science Advisory Board, 1200
Pennsylvania Avenue, NW, Washington, DC
* Members of this SAB Panel consist of: a) SAB Members: Experts appointed by the Administrator to serve on one
of the SAB Standing Committees, b) SAB Consultants: Experts appointed by the SAB Staff Director to a one-year
term to serve on ad hoc Panels formed to address a particular issue, c) Liaisons: Members of other Federal Advisory
Committees who are not Members or Consultants of the Board, d) Federal Experts: The SAB charter precludes
Federal employees from being Members of the Board. "Federal Experts" are federal employees who have technical
knowledge and expertise relevant to the subject matter under review or study by a particular panel.
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Brief Bios of the Metals Assessment Panel
Dr. Bruce A. Fowler Ph.D., Fellow A.T.S. received a B.S. degree in Fisheries (Marine Biology)
from the University of Washington in 1968 and a Ph.D. in Pathology from the University of
Oregon Medical School in 1972. He was a staff scientist at the National Institute of
Environmental Health Sciences from 1972 until 1987 when he became Director of the
University of Maryland System -wide Program in Toxicology and Professor of Pathology at the
University of Maryland School of Medicine. In 2001, he became Professor and Director of the
Laboratory of Cellular and Molecular Toxicology in the Department of Epidemiology at the
University of Maryland School of Medicine. In August 2002, he will go on an IP A assignment
as a Senior Research Advisor to the Agency for Toxic Substances and Diseases Registry
(ATSDR) in the Division of Toxicology.
Dr. Fowler, who is an internationally recognized expert on the toxicology of metals has
served on a number of State, National and International Committees in his areas of expertise.
These include the Maryland Governor's Council on Toxic Substances (Chair), National
Academy of Sciences / National Research Council Committees on Toxicology, Toxicology
Information Committee, Committee on Women in Science and Engineering, Measuring Lead in
Critical Populations (Chair), Biological Markers of Urinary Toxicology, Committee on the
Evaluation of Augmenting Potable Water Supplies with Reclaimed Water, and the
Subcommittee on Arsenic in Drinking Water of the Committee on Toxicology. He has also
served as a temporary advisor to the World Health Organization (WHO) and the International
Agency for Research Against Cancer (IARC). Dr Fowler has been honored as a Fellow of the
Japanese Society for the Promotion of Science (1990), a Fulbright Scholar and Swedish
Medical Research Council Visiting Professor at the Karolinska Insititute , Stockholm , Sweden
(1994 -1995) and elected as a Fellow of the Academy of Toxicological Sciences (2000). He
currently serves as Chairman of the Scientific Committee on the Toxicology of Metals under the
International Commission on Occupational Health (ICOH), as a consultant to the USEPA
Science Advisory Board and a member of the Fulbright Scholarship review committee for
Scandinavia (1999-, Chair, 2000-2001). He is a member of the AAAS Recruitment and
Screening Committee for the Court Appointed Scientific Experts (CASE) Demonstration Project
2000.
Dr. Fowler is the author of over 195 research papers and book chapters dealing with
molecular mechanisms of metal toxicity and biomarkers for early detection of metal-induced
cell injury. He has been the editor or co-editor of 4 books or monographs on metal toxicology
and mechanisms of chemical - induced cell injury. His current research is focused on the
toxicology of chemical mixtures involving metals, particularly in relation to semiconductors,
lead, cadmium, arsenic mixtures and the role(s) of lead - binding proteins in mediating the
toxicity of this ubiquitous metal to the kidney and brain. He serves on the editorial boards of a
number of scientific journals in toxicology and environmental health. Dr. Fowler has peer-
reviewed research funding from the EPA STAR Grant Program and the National Institutes of
Health.
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Dr. Andrew J. Friedland is Professor and Chair of the Environmental Studies Program at
Dartmouth College. His research has focused on understanding the effects of atmospheric
deposition of pollutants on elemental cycling processes in high-elevation forests of New England
and the Northeastern United States. He has examined the processes and behavior of trace
elements such as lead, copper, zinc, nickel and cadmium and major elements such as nitrogen
and calcium on vegetation, soils and water. In a number of related projects, he has described the
decline of red spruce in the mountains of New England and has examined water relations in
conifers during winter. Friedland has published approximately 40 peer-reviewed articles on
these topics. He has written one book, co-authored with biologist Carol Folt, Writing Successful
Science Proposals (Yale University Press, 2000). Dr. Friedland has received funding from the
National Science Foundation, the US Forest Service, the Environmental Protection Agency and
private foundations.
Dr. Friedland has taught introductory and advanced environmental science courses as
well as soil science, forest biogeochemistry and an interdisciplinary course on science and
literature. He was a member of the Citizens Advisory Panel of the Strategy for Vermont's Third
Century, an environmental risk assessment program conducted by the State of Vermont and the
U.S. EPA. From 1995-1998, he chaired the College Board Advanced Placement Environmental
Science development committee. This committee designed the first Advanced Placement course
in environmental science that was offered nationwide for the first time in 1998. Approximately
25,000 students took the most recent AP Environmental Science exam earlier in 2002. Dr.
Friedland is a member of the Soil Science Society of America, the Ecological Society of
America and the American Association for the Advancement of Science. He is currently on the
editorial boards of the Journal of Sustainable Forestry and Science of the Total Environment.
Friedland has B.A.s in Biology and Environmental Studies (double major) (1981) and a Ph.D. in
Geology (1985), all from the University of Pennsylvania.
Dr. Kim Hayes is Professor and Program Director of the Environmental and Water Resources
Engineering Program in the Department of Civil and Environmental Engineering at the
University of Michigan.
Professor Hayes' research focuses on the effects of interfacial properties on transport and
transformation processes of environmental contaminants, with more than 20 years of experience
in conducting experiments on the sorption of heavy metal ions and radionuclides to soil and
sediment mineral constituents. His recent research activities include surface spectroscopic
investigations of metal ion sorption reactions; impact of trace metal sorption processes on
organic pollutant transformation rates; reductive dechlorination by reduced mineral surfaces in
anaerobic environments, investigation of nanostructured particles for remediation of metal
contaminated groundwaters, sequestration of metals in the subsurface through precipitation and
sorption processes; and the study of binders and barriers materials for nuclear waste
containment. Support for this work has been provided by the Environmental Protection Agency,
the National Science Foundation, Department of Energy, and National Institute for
Environmental Health Sciences.
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Professor Hayes is presently serving as a reviewer of a National Research Council report
on the "Bioavailability of Contaminants in Soils and Sediments." He recently served as a
member of a peer-review panel for the Strategic Environmental Research and Development
Program (SERDP) to evaluate proposals on "In-Situ merits of Sequestration Enhancement and
Engineered Bioavailability Reduction of Metals in Soils." He has also participated on a variety
other workshop and review panels for the Environmental Protection Agency, National Science
Foundation, and Department of Energy related to metal ion speciation, sequestration and
mobility. Professor Hayes is currently a member of the Board of Director's and an Executive
Officer of the Association of Environmental Engineering and Science Professors as well as a
member of the Technical Advisory Board of the Great Lakes Protection Fund for the state of
Michigan.
Professor has more than 100 publications in peer-reviewed manuscripts, book chapters,
technical reports, and proceedings detailing work on environmental chemistry and interfacial
processes for contaminant remediation. Professor Hayes was awarded a National Science
Foundation Presidential Young Investigator Award earlier in his career (1989-1994). His
research group has been selected 4 times for American Chemical Society Environmental
Chemistry paper awards (1992, 1996, 1997, 1999).
Professor Hayes obtained his BS degree in Chemistry (1980), MSE in Environmental
Engineering (1980), MSE Chemical Engineering (1982), a Ph.D. in Environmental Engineering
(1987), all from Stanford University.
Dr. Mary Kay O'Rourke is an Associate Professor of Public Health Research and Medicine at
the University of Arizona in the Environmental and Community Health Division. She has
conducted interdisciplinary environmental research relating environmental exposure to human
health for over 22 years. O'Rourke holds degrees in geology (B.A. Alfred University) and
geosciences (M.S. Ph.D. The University of Arizona) with minors in the biosciences.
Her current research addresses exposures to Coccidioides immitis, arsenic and other
metals and pesticides. She has directed several exposure assessment surveys investigating metal,
pesticide, VOC and PAH exposures. She directed two surveys examining pesticide exposure
among children in Yuma Co. Arizona and a pesticide exposure in the Gila River Indian
Community. She was Co-Principal Investigator of the National Human Exposure Assessment
Survey and the Arizona Border Survey. These studies utilize multimedia and multipathway
approaches to exposure assessment. She has extensive experience in designing and
implementing exposure assessment field surveys, quality assurance programs and the data
processing protocols for large studies. Prior to joining the College of Public Health, she
evaluated human symptom response to bioaerosols (pollen, fungi, house dust mites) using the
tools of exposure assessment in a cross-sectional population of the Pima County (AZ) work
force. Projects have been funded by the Environmental Protection Agency, National Cancer
Institute, Centers for Disease Control, the Arizona Disease Control Research Commission, and
Arizona Department of Health Services.
Dr. O'Rourke has served on several panels and workshops for NIEHS and EPA; these
include: "Technical Workshop on Issues Associated with Considering Developmental Changes
Bios - 3
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in Behavior and anatomy when assessing Exposure to Children," Example Exposure Scenarios,"
"Lessons Learned from the National Human Exposure Assessment Survey," and " Fat Intake
Analysis." Dr. O'Rourke was a Councilor for the International Society of Exposure Analysis
and a past Secretary-Treasurer of the Pan-American Aerobiology Association (1989-1993).
O'Rourke served as the Secretary General of the International Association for Aerobiology
(IAA) from 1990-1994 and as an IAA councilor from 1994-98. She is a past member of the
review boards of Grana and Aerobiologia.
Dr. Charles A. Pittinger is an environmental toxicologist with broad experience in risk
assessment and risk management and technical policy development. He is currently Principal
Scientist with the Cadmus Group, Inc., a multi-disciplinary consulting firm specializing in
ecological risk assessment, air and water issues, energy efficiency and global climate processes.
He previously served as Director of Research for SoBran, Inc., managing a division of some 50
people supporting federal environmental research contracts with USEPA ORD Laboratories,
including contracts with NERL and NHEERL. The majority of Dr. Pittinger's professional
career was spent with Procter & Gamble, where he served as Section Head and Principal
Scientist for their corporate Human & Environmental Safety Division for 17 years.
Dr. Pittinger has conducted and managed R&D programs involving extensive field
monitoring, assessment and laboratory studies for private companies and trade associations, has
led peer reviews, conducted regulatory policy development and negotiations for industry and
government. His regulatory experience in the U.S. and abroad extends to consumer product
ingredients and industrial chemical registrations; site contamination and remediation; natural
resource management; and effluent permitting.
Dr. Pittinger has diverse experience in a range of technical areas including: ecological
risk assessment; hazard and risk management; risk communications; pollution prevention; life-
cycle analysis; ecological indicators of sustainability; persistent, bioaccumulative and toxic
substances; and high production volume chemicals.
Dr Pittinger's work has required close coordination among internal business sectors and
external regulatory (e.g., USEPA OPPTS, ORD and the Science Advisory Board (SAB),
Organization for Economic Cooperation and Development), trade (e.g., American Industrial
Health Council, American Chemistry Council, Soap & Detergent Association, Alliance for
Chemical Awareness), non-profit (e.g., The John F. Heinz III Center, International Life Sciences
Institute), academic and professional scientific organizations (e.g., Society for Environmental
Toxicology and Chemistry, Society for Risk Analysis). He is currently a member of the SAB's
Ecological Processes and Effects Committee.
Dr. Pittinger earned his doctorate in zoology (environmental toxicology) from Virginia
Polytechnic Institute and State University. He received a Master's Degree in Ecology from The
University of Tennessee, and a Bachelor's Degree in Biology from the University of Notre
Dame.
Dr. Valerie M. Thomas
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Current Position: Research Scientist, Princeton Environmental Institute, Princeton University
Educational Background: Ph.D., Theoretical Physics, Cornell University; B. A. (High Honors),
Swarthmore College
Area of Expertise: Sources, emissions and fate of pollutants, including lead, cadmium, mercury,
and dioxin. Industrial ecology. End-of-life management of products. Use of quantitative methods
for environmental policy.
Research Activities: Current research projects include: Phase-out of leaded gasoline in Africa.
The content of lead, cadmium, and mercury in electronic products. Electronic and optical tags for
product end-of-life management. Economics of second-hand markets. Sources of dioxin.
Development of research agendas for industrial ecology.
Service on other advisory committees, professional societies, especially those associated with
issues under discussion in this review
Member, U.S. EPA Science Advisory Board (SAB), Environmental Engineering Committee,
appointed October 2000. Co-chair, Subcommittee on Industrial Ecology.
Consultant, U.S. EPA Science Advisory Board, 1995-2000.
2000: Review of EPA Dioxin Reassessment.
Review of Residual Risk Case Study (for Clean Air Act residual risk
assessments)
1996-99 '.Integrated Risk Project. Human Exposure and Health, and Steering
Committee.
1997: Review of EPA'sReport to Congress onMercury. Chair, sources working
group.
1995: Review of EPA Dioxin Reassessment: Exposure Panel.
Consultant on use and sources of cadmium, New York Academy of Sciences, New York-New
Jersey Harbor Industrial Ecology Project. 2002.
US Director, Russian Lead Project. Participants from a range of Russian NGO, scientific,
industry, and governmental organizations, and with participants from the Johns Hopkins School
of Hygiene and Public Health, and the International Lead Management Center. 1997-2000.
New Jersey Comparative Risk Project, NJ Department of Environmental Protection (DEP):
Ecosystem Technical Working Group, and Project Team. 1999-2001.
Consultant to Environmental Defense, on vehicle emissions, 2000.
Co-Organizer (with R. Socolow and C. Andrews). NSF-sponsored Workshop on Industrial
Ecology and Policy, White House Conference Center, April 1998.
Technical Expert to US Delegation, OECD Workshop on Lead Products, Toronto, Sept. 1994.
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Sources of recent grant and/or contract support
AT&T Foundation
US Environmental Protection Agency
National Science Foundation
New York Academy of Sciences
New Jersey Department of Environmental Protection
US Agency for International Development (pending)
Dr.Nga Tran is a Senior Managing Scientist at Exponent's Food & Chemicals practice, and is
based in Washington, DC. Dr. Tran has more than 15 years of experience in environmental and
occupational health risk assessment and management in the private and public sectors and
academia. Dr. Tran has worked on a wide range of issues, including health surveillance strategy
at the Department of Defense (DOD) cleanup sites, chemical and radiation risk harmonization at
the Department of Energy's (DOE) cleanup sites, methodology for assessing and prioritizing
environmental health threats to military personnel deployed overseas, environmental insurance
risks, probabilistic exposure/risk assessment, dietary exposure assessment, product stewardship,
industrial hygiene and epidemiology. Prior to joining Exponent Dr. Tran was a faculty member
at the Johns Hopkins University, Bloomberg School of Public Health where she conducted
research and taught exposure and risk assessment, risk prioritization, and risk harmonization. Dr.
Tran remains an Adjunct Assistant Professor at the university.
Dr. Tran had served as a Special Assistant to the Assistant Secretary for Environment,
Safety and Health at DOE where she was an active participant in the inter-agency efforts to
coordinate risk assessment, cost-benefit analysis and regulatory reform issues. She advised the
Assistant Secretary on risk policy decisions as they relate to cleanup efforts at DOE sites. Dr.
Tran is also a Certified Industrial Hygienist with experience in developing and implementing
cost-effective health and safety and product stewardship programs. As a Corporate Public
Affairs Manager, she had successfully implemented risk communication programs, counseled
and trained facility managers on effective community relations, implemented an industry
community outreach initiative (the Chemical Manufacturing Association-Community
Awareness/Emergency Response, (CMA-CAER), consulted facility managers on media
relations, advised corporate officers on public policy matters, and worked with the Company's
lobbyists to develop legislative position/strategy on issues critical to the business operations.
Dr. Tran has served on a number peer review panels sponsored by the EPA, including
"Comparative Dietary Risks: Balancing the Risks and Benefits of Fish Consumption" (2000),
"National Human Exposure Analysis Survey (NHEXAS) Data Analysis Strategy" (1999),
"Water Quality Criteria Methodology: Human Health - Federal Register Notice" and "Ambient
Water Quality Criteria Derivation Methodology Human Health - Technical Support Document"
(1999). Dr. Tran is a member of the American Industrial Hygiene Association, Risk
Assessment Committee (1996-) and the Technical Advisory Committee for the development of
EPA's Aggregate and Cumulative Exposure and Risk Assessment Model (Lifeline™ Project)
(1999-).
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Dr. Tran was a Kellogg Fellow in the Doctor of Public Health program at the Johns
Hopkins University, Bloomberg School of Public Health. Her dissertation was on U.S. food
safety policy and pesticide risks.
Credentials and Professional Honors
Dr.P.H., Johns Hopkins University, Bloomberg School of Public Health, 1995
M.B.A., DePaul University, 1991
M.P.H., Yale University, Department of Epidemiology and Public Health, 1985
B.A., Biology, Whitman College, 1982
Sources of recent grant and/or contract support
National Academy of Sciences/National Research Council (2002)
3M (2002)
FMC (2002)
AIG Environmental (2001-2002)
U.S. Department of Defense (2000-01; 1996-98)
U.S. Department of Agriculture (1999-2000)
U.S. EPA and The Environment Law Institute (1997-2000)
The Pew Charitable Trusts (1999-2001)
Dr. Bernard Weiss is Professor of Environmental Medicine and Pediatrics at the University of
Rochester School of Medicine and Dentistry, where he has been a member of the faculty since
1965. Before coming to Rochester, he served on the faculty of the Johns Hopkins School of
Medicine, and, earlier, held an appointment at the U.S. Air Force School of Aviation Medicine.
He earned a B.A. in psychology at New York University and a Ph.D. from the University of
Rochester also in Psychology.
Dr. Weiss has served as a member of many committees and panels devoted to toxicology
and environmental health, including those organized by the U.S. Environmental Protection
Agency's Science Advisory Board (for example, the Dioxin Reassessment Review Panel and the
subcommittee on human testing of pesticides, and earlier served as chair of the Subcommittee on
Metals), and the National Academy of Sciences (for example, the recent Committee on Air
Quality in Passenger Aircraft). He is especially concerned with risk assessment issues arising
from the effects of environmental chemicals on brain development and brain aging. He is the
editor or co-editor of seven books and monographs and author or co-author of over 200 articles.
His special interests and publications lie primarily in areas that involve chemical influences on
behavior; these include the neurobehavioral toxicology of metals such as lead, mercury and
manganese; endocrine disrupters such as dioxin; solvents such as toluene and methanol; drugs
such as cocaine; and air pollutants such as ozone. Current and recent grant support have been
provided by NIH (specifically, the National Institute of Environmental Health Sciences) and
ATSDR (Agency for Toxic Substances and Disease Registry).
Dr. Herbert Windom is a geochemist at the Skidaway Institute of Oceanography where he has
been employed since 1968. He was Acting Director from 1/94 until 3/2001 at which time he
became an Emeritus Professor. He is also an Adjunct Professor at the University of Georgia and
Bios - 7
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at Georgia Tech from which most of his graduate students come. Over the past thirty plus years
his research has focused the transfer and fate of trace elements in riverine, estuarine and coastal
marine environments and the contamination of these systems from land-based sources. And to
understand how such things as watershed characteristics, climatology and human intervention
affect processes, he has conducted studies in various parts of the world from the Russian Arctic
to the Asian tropics and has studied heavily impacted as well as relatively pristine systems. This
research has been/is funded by NSF, NOAA, EPA, ONR, DOD and other State and Federal
agencies. Past national and international service includes the United Nations sponsored Group of
Expert on the Protection of the Marine Environment (Chairman), several environmental
committees of the International Council for the Exploration of the Seas and UNESCO and
several review committees and panels for National and State environmental programs. Present
service includes EPA's Board of Scientific Councilors, the Coastal Advisory Council for the
State of Georgia and several additional State, private and professional boards, panels and
committees Dr. Windom received his BS from Florida State University and MS and Ph.D
degrees from the University of California, San Diego (Scripps Institution of Oceanography)
Bios - 8
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NOTICE
This report has been written as part of the activities of the EPA Science Advisory Board,
a public advisory group providing extramural scientific information and advice to the
Administrator and other officials of the Environmental Protection Agency. The Board is
structured to provide balanced, expert assessment of scientific matters related to problems facing
the Agency. This report has not been reviewed for approval by the Agency and, hence, the
contents of this report do not necessarily represent the views and policies of the Environmental
Protection Agency, nor of other agencies in the Executive Branch of the Federal government, nor
does mention of trade names of commercial products constitute a recommendation for use.
Distribution and Availability: This EPA Science Advisory Board report is provided to the EPA
Administrator, senior Agency management, appropriate program staff, interested members of the
public, and is posted on the SAB website (www.epa.gov/sab). Information on its availability is
also provided in the SAB's monthly newsletter {Happenings at the Science Advisory Board).
Additional copies and further information are available from the SAB Staff [US EPA Science
Advisory Board (1400A), 1200 Pennsylvania Avenue, NW, Washington, DC 20460-0001;
202-564-4533].
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