United States
Environmental Protection
Agency
Office of Research and
Development
Washington, DC 20460
EPA/600/R-98/087
February 1998
www.epa.gov
Research Plan for
Endocrine Disruptors
                      Estradiol-17(3

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On the cover: Three dimensional ball and stick representation of estradiol-17p. The model and
surface were constructed with the Sybyl and MolCad molecular modeling packages, by Tripos
Associates, St. Louis, MO. The aromatic A ring is depicted to the left. The surface surrounding
the ball and stick figure represents the electron density volume of the estradiol-17(3 that might be
recognized by the estrogen receptor protein. Computer modeling approaches such as these are
used to explore physical-chemical properties that either promote or deter ligand-receptor binding
interactions and thus can aide in the construction of predictive structure-activity relationships
for environmental chemicals. Figure courtesy of Dr. Tom Wiese,  University of North Carolina
Curriculum in Toxicology Research  Fellow.

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                          ORD Research Plan for Endocrine Disrupters
  OFFICE OF RESEARCH AND DEVELOPMENT
  US ENVIRONMENTAL PROTECTION AGENCY
RESEARCH PLAN FOR ENDOCRINE DISRUPTORS
              February, 1998

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                                                ORD Research Plan for Endocrine Disrupters

                                 FOREWORD

      The 1996 Strategic Plan for the Office of Research and Development (ORD) sets
forth ORD's vision,  mission, and long-term research goals.  As  part of this strategic
process, ORD used the risk paradigm to identify EPA's top research priorities for the next
several years. The ORD Strategic Plan is thus the foundation for the research strategies
and research plans that ORD has developed, or is in the process of developing, to identify
and describe individual high-priority research topics.  A research plan is different from a
research strategy. While a  research strategy provides the framework for making and
explaining decisions about program purpose and direction, as well as relative priorities and
research distributions, a research plan defines the research program that EPA is pursuing.
The research strategy, as an overarching view of research needs and priorities, forms the
basis for the research plan and provides a  link between the ORD Strategic Plan and the
individual research plan. In turn, the research plan links the research strategy to individual
laboratory implementation plans (which serve as the blueprints for work at ORD's national
laboratories and centers) by defining the research topic at the project level. One of these
high-priority research topics is endocrine disrupting chemicals (EDCs).

      The   Research  Plan  for Endocrine  Disrupters was  developed  through
recommendations from two EPA workshops (April 1995 in Raleigh, NC, covering human
and ecological needs from a broad-scale,  risk-assessment-based approach; and June
1995 in  Duluth, MN, focusing on ecological research needs) and  their subsequent risk
assessment  breakout  groups, the scientific judgment of the  ORD Research  Planning
Committee, and internal and external peer reviews. ORD developed this research plan
because of the possibility of serious effects on human and wildlife populations and the
persistence of some EDCs in the environment.

      The key scientific questions the EDC research plan sets out to address are:

*•     What EDC-related  effects  are  occurring in  exposed  human and wildlife
      populations?
*•     What are the  chemical classes of interest and their potencies?
*•     What are the  dose-response characteristics in the low-dose region?
*•     Do EPA's testing guidelines adequately  evaluate potential endocrine-mediated
      effects?
*•     What extrapolation tools are needed?
      What are the  effects of exposure to  multiple EDCs, and will a toxicity equivalency
      factor (TEF) approach be applicable?
      How and to what degree are human and wildlife populations exposed to EDCs?
      What are the  major sources and environmental fates of EDCs?
      How can unreasonable risks be managed?
      To answer these questions, the EDC research plan  establishes the following
research priorities in the form of ten broad categories of research needs: basic research,
biomarkers, database development, exposure determination, exposure follow-up, mixtures,

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                                                ORD Research Plan for Endocrine Disrupters

multi-disciplinary studies, risk assessment methods, hazard identification, and sentinel
species.

      This research plan is an important accountability tool because it makes clear the
rationale for, and the intended products of, EPA's endocrine  disrupter research. By
specifying in advance how EPA will manage its scientific data and information products,
EPA can communicate the  results  of its EDC  research effectively to  its  clients,
stakeholders, and the public. This research plan is also an important budget tool, enabling
EPA to clearly track progress toward achieving its EDC research goals, as required by the
1993 Government Performance and Results Act.
                                     Lawrence W. Reiter, Ph.D.
                                     Acting Deputy Assistant Administrator
                                      for Science, ORD

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                                               ORD Research Plan for Endocrine Disrupters
                                PEER REVIEW
      Peer review is an important component of research plan development. The peer
review history for this research plan follows:
      Initial Internal Agency Review:

      ORD Science Council:

            Lead Reviewers:
      Submitted for Comments
      to the Endocrine Disrupter
      Working Group of the
      Committee on the
      Environment and
      Natural Resources (CENR)

      External Peer Review:

            Reviewers:
February, 1996

Final Clearance, December, 1996

Rick Linthurst, NERL
Jennette Wiltse, NCEA
            April, 1997

July 8-9, 1997, Washington, DC.
                  William Cooper, Michigan State University
                  George Daston, Procter & Gamble Co.
                  Peter DeFur, Virginia Commonwealth University, Chair
                  Paul Foster, Chemical Industry Institute of Toxicology
                  Michael Fry, University of California, Davis
                  Louis Guillette, University of Florida
                  Holly Hattemer-Frey, SAF*Risk
                  Susie Humphreys, U.S. Food and Drug Administration
                  Timothy Kubiak, U.S. Fish and Wildlife Service
                  Stephen Safe, Texas A&M University
                  Susan Shober, National Center for Health Statistics
                  Richard Seegal, New York State Department of Health

            Coordinated by:     Eastern  Research  Group, Inc.
                              Bill Word, Risk Assessment Forum, Project Officer
      Final Acceptance by ORD:

            ORD Executive Lead:
      March, 1998

      Larry Reiter, NHEERL
                                      IV

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                     ORD Research Plan for Endocrine Disrupters




        AUTHORS







   Gerald Ankley, NHEERL




     Elaine Francis, OSP




     Earl Gray, NHEERL




Robert Kavlock, NHEERL, Chair




 Suzanne McMaster, NHEERL




   David Reese, NCERQA




    Greg Sayles, NRMRL




    Anne Sergeant, NCEA




    Daniel Vallero, NERL

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                                             ORD Research Plan for Endocrine Disrupters

                           TABLE OF CONTENTS
I. INTRODUCTION 	1
II. REGULATORY BACKGROUND	5
III. RESEARCH ISSUES  	7
IV. RESEARCH APPROACH AND ACTIVITIES  	10
      Biological Effects Studies  	12
            Issue 1.  Chemical Classes and Potencies	12
            Issue 2.  Testing Protocols  	13
            Issue 3.  Dose Response Relationships  	13
            Issue 4.  Endocrine Profiles in Wildlife	15
            Issue 5.  Extrapolation to Populations	16
            Issue 6.  Mixtures	18
      Exposure Studies  	19
            Issue 1.  Characterization Framework	19
            Issue 2.  Exposure Assessment Tools	20
            Issue 3.  Environmental Concentrations  	22
      Linkage Studies	24
            Issue 1.  Risk Assessment Integration	24
            Issue 2.  Exposure Characterization  	25
            Issue 3.  Status and Trends	27
            Issue 4. Risk Management Approaches  	28
V. RESEARCH IMPLEMENTATION GUIDANCE	30
VI. REFERENCES 	32
APPENDIX I.  TIME LINES TO ADDRESS OVERARCHING QUESTIONS  	33
APPENDIX II. SUMMARY DELIBERATIONS OF EPA WORKSHOPS 	34
APPENDIX III. RESEARCH MATRIX FROM ORD STRATEGIC PLAN 	36
APPENDIX IV. CROSS TABULATION OF ISSUES WITH RESEARCH QUESTIONS 	39
APPENDIX V. FOCAL AREAS, PRIORITY AND TIME FRAME FOR ISSUES 	42
APPENDIX VI. PRIORITY RANKING FACTORS	45
APPENDIX VII. GPRA ALIGNMENT	47
                                    VI

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                                                    ORD Research Plan for Endocrine Disrupters

I. INTRODUCTION

       It has been suggested that humans and domestic and wildlife species have suffered
adverse health consequences resulting from exposure to environmental chemicals that interact
with the endocrine system. However, considerable uncertainty exists regarding the relationship(s)
between adverse health outcomes and exposure to environmental contaminants.  Collectively,
chemicals with  the  potential to interfere with the function of endocrine systems are called
endocrine disrupting chemicals (EDCs).  EDCs have been defined as exogenous agents that
interfere with the production, release, transport, metabolism, binding, action, or elimination of the
natural hormones in the body responsible for the maintenance of homeostasis and the regulation
of developmental processes.

       To date, these problems have been identified primarily in wildlife species with relatively
high  exposures to  specific compounds,  including organochlorines such  as DDT  and  its
metabolites, PCBs and dioxins, or in domestic animals foraging on plants with high levels of
phytoestrogens (Kavlock et al., 1996).   Effects noted in wildlife that have a  documented or
presumed relationship to altered endocrine function include imposex in molluscs exposed to the
alkyltins, vitellogenin induction in fish living near sewage outfalls (recently linked to concentrations
of ethynyl estradiol),  changes in sex steroids in fish near kraft-mill outfalls, abnormal reproductive
development in  alligators in Lake Apopka following a pesticide spill, nearly complete mortality of
Lake Ontario lake trout in the  sac-fry stage (presumably resulting from exposure to dioxin-like
compounds), eggshell thinning in  birds from exposure to DDT  and its metabolites, and birth
defects in Lake  Michigan cormorants exposed to PCBs and  other Ah-receptor ligands. Also, a
variety of adverse effects on reproductive development have been observed in laboratory rodents
exposed to very low levels of dioxin.

       In humans, the consequences of prenatal exposure to DES on the reproductive tract of
both  females and males are well known and developmental neurological problems have been
identified in children exposed to PCBs and/or PCDFs. In addition, reports of declines in the quality
and quantity of sperm production in humans over the last four decades, and increases in certain
cancers (breast, prostate,  testicular) that may have an endocrine-related basis  have led to
speculation about environmental etiologies.

       Despite these reported effects, we know little about their causes and the concentrations
of EDCs that would induce effects in various populations.  Nevertheless, it is known that the
normal functions of all organ systems are regulated by endocrine factors. Small disturbances in
endocrine function,  especially during certain stages  of the life  cycle such as development,
pregnancy and lactation, can lead to profound and lasting effects. Based upon recognition of the
potential scope  of the problem, the  possibility of serious effects on the health of populations, and
the persistence  of some endocrine-disrupting agents in the environment, research on endocrine
disrupters was identified as one of the six high-priority topics in the ORD Strategic Plan (USEPA,
1996a). If future health effects and exposure studies conclude that humans and the ecosystem
are at significant risk due to exposure to EDCs, research on how best to lower or eliminate the risk
will be  needed.  The key questions that this research plan must answer are:

             >> What effects are occurring in exposed human and wildlife populations?
             >> What are the chemical classes of interest and their potencies?
             >> What are the dose-response characteristics in the low-dose region?
             >> Do our testing guidelines adequately  evaluate potential endocrine-mediated

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                                                    ORD Research Plan for Endocrine Disrupters

                    effects?
             >> What extrapolation tools are needed?
             >~ What are the effects of exposure to multiple EDCs, and will a TEF approach be
                    applicable?
             >~ How, and to what degree, are human and wildlife populations exposed to EDCs?
             >> What are the major sources and environmental fates of EDCs?
             >~ How can unreasonable risks be managed?

      A time line for addressing these overarching questions is presented in Appendix I.

      Given EPA's mandate to protect both public health and the environment, the Agency is in
a unique position to provide leadership in this area. Therefore,  in response to the growing public
health concerns related to chemicals in the environment that have the potential to act as endocrine
disrupters, EPA's Office of Research and Development (ORD) held two workshops at which the
opinions of international experts were sought to help formulate a national research plan.  The first
of these was held in April 1995 in Raleigh, NC, and covered both human and ecological needs
from a broad-scale, risk-assessment-based  perspective (Kavlock et al., 1996).  The second
workshop, held in Duluth, MN, in June 1995 built on the needs identified in the first workshop, but
with a focus on ecological research needs (Ankley et al.,  1997). Details of the deliberations and
recommendations of these workshops are summarized in  Section III  (Research Issues) and
Appendix II.  This research plan was developed from the  recommendations provided by  the
workshops, the scientific judgment of the ORD Research Planning Committee, reviews and input
from the chairpersons for the risk assessment breakout groups of the Raleigh workshop, internal
peer reviewers from across the Agency, the ORD Science Council, and an external peer review
panel convened by the Agency's Risk Assessment Forum.

      The broad nature of the issue necessitates a coordinated effort on both the national and
international  level.  The National Science and Technology Council (NSTC), which advises  the
President and  his Cabinet on  directions for federal  research and  development efforts, has
established a milestone for 1995-1998 to  produce a national research strategy on endocrine
disrupting chemicals. This action led to formation of  the Endocrine Disrupter Working Group
under the Committee on the Environment and Natural Resources (CENR) of the NSTC  to guide
activities on a broader national scale (CENR,  1996). EPA chairs this coordination effort and has
been instrumental in establishing a communication network on endocrine disrupters  that  will
facilitate addressing the key research questions. The functions of the CENR workgroup are to:

       !      develop a federal research framework;
       !      inventory ongoing research activities in the federal government and elsewhere;
       !      provide a forum for information sharing among the various national organizations;
       !      outreach to non-federal organizations involved in endocrine disrupter issues; and
       !      hold  periodic symposia as the research emerges.

      The inventory of federal research on endocrine disruption has  been used to evaluate the
current state of the federal effort,  identify research gaps and establish  priorities, and clarify
governmental roles and responsibilities. To date, nearly 400 projects have been identified as being
sponsored by the 14 participating agencies.  The CENR framework and the inventory are available
on the Internet  (http://www.epa.gov/endocrine), and a summary analysis has been published
(Reiter, et al., 1998).  Due to the complex nature of the uncertainties posed by the endocrine
disrupter hypothesis, the overlapping concerns of federal agencies, and the resource constraints

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                                                    ORD Research Plan for Endocrine Disrupters

 on the federal budget,  close coordination and cooperation among federal agencies will be
essential to the resolution  of the critical research questions.   For example, a  number of
participating agencies issued a joint Request for Proposals in FY98 to address the highest priority
data gaps.  While the CENR will provide the umbrella for this coordination, individual agencies
are responsible for development of their own independent research plans. Therefore, an important
component of this present document must be to communicate with other federal organizations on
EPA's goals, priorities, and projected accomplishments.

       EDCs were also identified as a high priority at the 1997 Environment Leaders' Summit of
the Eight.  Included among the recommended action items were:  1) the development of an
international inventory of ongoing  research activities; 2) the development of an international
scientific assessment; 3) the development of an international research strategy after completion
of the inventory and scientific assessment; and 4) support for an Organization of Economic and
Community Development (OECD) initiative to develop a  battery of screening  and testing
guidelines for  EDCs that considers the special susceptibilities and exposures to children. In
conjunction with the CENR effort, a companion effort to inventory research has been conducted
in Europe (http://www.liwa.de/rneed), and efforts are currently underway under the auspices of
the World Health Organization's International Programme on Chemical Safety and OECD to
assemble an international inventory and assessment of the endocrine disrupter issue.  In addition,
the National Research Council has also been commissioned by EPA's Office of Water and other
federal agencies to conduct a comprehensive, critical evaluation of the scientific literature and to
identify research needs.  Results of this effort are expected to be available in the spring of 1998.
In the interim, ORD's Risk Assessment Forum has provided  an overview of the current state of
knowledge  of the science relative to environmental  endocrine disruption in humans, laboratory
testing and  wildlife species (USEPA, 1996b).  This document contains an extensive assessment
of the principle adverse biological effects associated with exposure to endocrine-disrupting
chemicals.

       In developing EPA's research plan,  the committee noted that there are clearly important
areas for which other federal agencies have the research lead (e.g., the National Cancer Institute
and the Centers for Disease Control for studies on environmental causes of breast cancer, the
National Oceanic and Atmospheric Administration for immunological effects in marine mammals,
the National Science Foundation and the National Institute of Environmental Health Sciences for
the role  of hormones in the normal differentiation of  the brain and reproductive track).
Conversely, because of their scope and complexity, other problem areas need to be approached
by multiple  organizations (e.g., development of short-term  screening techniques, determination
of environmental contamination levels). In this plan, we first selected those areas where the EPA
should be  playing  at least a moderate role.  Priorities were then assigned based  upon an
assessment of the importance of the research to the EPA program offices, on the magnitude of
the uncertainties in the knowledge base, the sequence of research needed to obtain the final
answer,  the possibility that the  research would  result in a significant product  for hazard
identification, risk characterization or  risk management and, finally, the technical feasibility of
conducting  a successful project.  It  is expected  that other EPA activities (e.g.,  the Dioxin
Reassessment and efforts to develop approaches for assessment of complex mixtures) will feed
into the information base.

      This Research Plan for Endocrine Disrupters was developed to serve several purposes,
including:

              1. To provide a roadmap to guide the Agency's efforts on endocrine disrupters,

                                          3

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                                                    ORD Research Plan for Endocrine Disrupters

                    while  at the  same time  remaining  flexible  enough  to  adjust  to
                    recommendations evolving from the CENR and MAS efforts;

             2. To  establish distinctions between,  and  priorities for,  the  intramural and
                    extramural ORD research efforts;

             3. To provide a research framework for the regulatory programs;

             4. To inform Agency risk assessors and risk managers of the types of data being
                    generated for endocrine disrupting chemicals; and

             4. To serve as the basis for coordination and communication of research activities
                    with other Federal agencies and other organizations affected by this issue.

       Concepts for  a  multi-year research plan for the intramural and extramural programs
priorities are presented in Section V. It is anticipated that each Laboratory and Center within ORD
will develop an implementation plan for EDCs that allows the coordination and sequencing of the
research elements to occur.  Recognizing the dynamic nature of the research front, we emphasize
that the priorities and sequencing that we propose be revisited in three to four years so the
strategy can be modified accordingly.

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                                                    ORD Research Plan for Endocrine Disrupters

II. REGULATORY BACKGROUND

       The authorities and responsibilities of the Environmental Protection Agency are mandated
primarily by thirteen major environmental statutes (CRC Report to Congress,  1995).  These
statutes direct EPA to perform a wide variety of activities with the goal of protecting human health
and the environment. These diverse activities include, but are not limited to: 1)  identifying
hazardous or toxic substances; 2) setting specific allowable levels of exposure to chemicals that
are protective of human health and the environment; 3) controlling releases of chemicals into the
environment; 4) responding to spills or other releases of chemicals into the environment; 5)
developing a national inventory of chemical releases into the environment; 6) cleaning hazardous
waste sites to levels that assure protection of human health and the environment; 7)  evaluating
new  and existing chemicals for their ability to cause  potential adverse human health and
environmental effects and requiring the gathering of data on environmental exposure  levels and
potential human health and ecological effects when data are insufficient; and 8) reviewing and
analyzing  information that pesticide manufacturers submit in support  of registration  or
reregistration to determine that a pesticide will not cause unreasonable adverse effects on the
environment or to humans. Chemicals that are known or suspected of being endocrine disrupters
are included in these mandated activities.

       Recently, two environmental laws were enacted  that specifically require the testing of
pesticides and other chemicals found in or on food or in drinking water sources to determine their
?estrogenic or  other endocrine effects in humans." The  Food Quality Protection Act of 1996
(FQPA) and the Safe Drinking Water Act Amendments of 1996 (SDWA) require EPA to develop,
within two years of enactment, a screening program using validated test systems to  determine
whether substances  may have  an estrogenic  or other endocrine effects  in humans.  The
screening program must undergo a public comment period and peer review and be implemented
within three years. The laws require that the manufacturers, registrants, or importers conduct the
testing of the pesticides and other substances according  to the program EPA develops. At joint
workshops, cosponsored  by  EPA, the Chemical  Manufacturers Association, and  the World
Wildlife Fund, a number of assays potentially suitable for assessing EDCs (particularly exerting
(anti-) estrogenic/androgenic effects)  were identified and critiqued (Gray et al., 1997; Ankley et
al. 1998).

       Based upon  input from those workshops and others, the Endocrine Disrupter  Screening
and Testing Advisory Committee (EDSTAC), an advisory committee to EPA on implementation
of the FQPA and SDWA, is assembling a battery of assays for screening and testing potential
EDCs. These assays will be used to address the mandates of the FQPA and SDWA.   In addition
to in vitro gene transcription assays, proposed Tier 1 Screening Tests include mammalian assays,
such as the uterotrophic test for estrogen and a Hershberger type assay for androgen action, in
conjunction with a short-term fish reproduction test and an amphibian metamorphosis assay for
thyroid-mediated processes.  From a research planning perspective, the forthcoming EDSTAC
recommendations will be critical because several of the proposed non-mammalian screening and
testing assays will require some level of research to bring them to the point where they could be
considered standard methods.

       In summary, to meet the needs of all of its mandates, the Agency needs the tools to be
able to:

       1. Identify EDCs;

       2. Evaluate their potential effects on human health and the environment;

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                                                    ORD Research Plan for Endocrine Disrupters

       3. Discern when additional data are needed;

       4. Develop the appropriate protocols should additional data be required;

       5. Set allowable levels of exposure or releases to the environment that are protective of
             human health and the environment;

       6. Develop technological controls to prevent/reduce releases, in the first place; and

       7. Remediate the risks associated with in-place EDCs.
       While there is a wealth of data available on some endocrine disrupters,  much more
research is needed in order for the Agency to carry out its mandates.  For this reason, EPA is
embarking  on a  major research effort on endocrine disrupters.  The objective of the EDCs
research program is to improve our knowledge and understanding of endocrine disrupters in the
environment so that we can improve our methods of assessment.  This, in turn, will assist the
Agency in identifying the chemicals that pose an unreasonable risk, developing ways to prevent
or reduce their release into the environment, and developing means to remediate in-place EDCs
that pose an unreasonable risk.

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                                                     ORD Research Plan for Endocrine Disrupters

III. RESEARCH ISSUES

       Answering the questions posed for the research program in endocrine disruption listed in
the Introduction will entail a coordinated effort by the scientific community, for the scope is
exceedingly broad and beyond the capabilities of any one research organization. One function
of the CENR Working Group on Endocrine Disrupters is to assist in partitioning research functions
among the participating agencies so that limited resources are used most effectively.  Developing
methods for performing hazard and risk characterization of chemicals, quantitating exposure levels
and determining environmental fate of chemicals, and developing extrapolation tools, have been
traditional strengths of the EPA research program.  It is  these areas that we propose as our
primary contributions to the overall federal effort on EDCs.

       Through the research needs workshops in 1995, ORD has provided national leadership
in the endocrine disrupter issue by fostering communications across government, private industry,
and  the public. Several  general comments about future  research  on endocrine disrupting
chemicals emanated from the discussions at the workshops. These include:

       1. The great advantage  in bringing  together a multi-disciplinary group of scientists
             representing human health and ecological concerns to help identify common
             issues.

       2. Because exogenous endocrine disrupting chemicals must interact at some level with the
             natural receptor ligands within the body, and because the concentrations of the
             natural ligands are maintained within life-cycle dependent narrow limits suggest
             that the timing of exposure is a very significant factor in any assessment.

       3. Many EDCs are persistent in the environment and bioaccumulate, and exposures are
             widespread throughout the entire globe.

       4. The mechanistic basis of the interaction with biological systems presages the induction
             of subtle effects at low doses that must be interpreted as to their adversity.

       In general, it was felt that linking specific exposures to specific effects in the environment
often would be difficult due to the  complexities of exposure, the latency of the effects, and the at
times subtle nature of the outcomes.  Such  considerations will have significant effect on the
research activities necessary.  Ten broad categories of research needs were identified:  basic
research, biomarkers, database  development, exposure determination, exposure follow-up,
mixtures, multi-disciplinary studies, risk assessment methods, hazard identification, and sentinel
species.    Processes that  should  receive particular  attention  include  are  reproduction,
development, and immunocompetence.

       There is a  pressing need to identify the extent of the chemical universe of concern. This
clearly  cannot consist of testing all chemicals in long-term chronic assays with multiple species.
Tools that  should be quite useful  include short-term in  vitro and  in vivo assays as well as
structure-activity relationship models, which in virtually all cases require further development and
validation with multi-species chronic toxicity tests.  As noted in Section II, Congress mandated
EPA to develop a chemical program for environmental estrogens and other endocrine disrupters
by August 1998. The results of screening exercises using these types  of tools could be linked to
key exposure data, such as production  volume, persistence, etc. to help identify chemicals of
greatest concern and to provide focus for a monitoring program. These types of screening tools
would play

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                                                    ORD Research Plan for Endocrine Disrupters

significant roles in  both prospective and retrospective assessments of the human health and
ecological risks of EDCs. A key consideration in developing these types of methods and models
is the ability to link results obtained in suborganismal systems to organismal-level effects.

       To better assess the ecological risks of EDCs, work needs to be done to define linkages
between potential measures of effect (usually made at the level of the individual) and assessment
endpoints (which typically are at population and community levels). Similarly, linkages between
these measures at different levels  of biological organization  need to  be defined better.  For
example, induction of vitellogenin in male fish appears to be a very specific response to exposure
to estrogen mimics.  However, it is unclear what this means in terms of reproduction. The basic
challenge in this research area is to identify those measures that both indicate exposure to EDCs
and predict their effects in populations.  Furthermore, we must develop a better definition of
"normal" with respect to endocrine-regulated processes in commonly tested or monitored species
relative to effects manifested at the population level (the degree to which circulating levels of sex
steroids need to be altered before reproductive success is threatened).  Steps need to be taken
to  adapt  existing  assays used for ecological risk by incorporating exposure  during  key
developmental windows, and to ensure assessment of relevant endpoints for EDCs.

       A major issue for endocrine disruption that must be addressed is the need to define what
constitutes an "adverse" health  effect,  especially considering the multiple levels of  biological
observation (e.g., molecular to community level) at which  effects can be observed. According to
EPA's interim position (USEPA, 1996b), the Agency does  not consider endocrine disruption to be
an adverse endpoint per se, but rather to  be a mode  of action  potentially relating to other
outcomes, routinely used in reaching regulatory decisions, such as carcinogenic, reproductive or
developmental effects. The document goes on to state that

       "In general,  due to the precise  yet adaptable  control mechanisms  and the
       intertwined nature of hormonal balance, modest amounts of chemical exposure
       seldom compromise normal physiological functions.   Fluctuations of hormone
       concentration and receptor activities, by design, absorb some of environmental and
       physiological challenges to  maintain homeostasis in  adults.  Only when the
       equilibrium control mechanisms are overwhelmed do deleterious effects occur. An
       important question is whether  homeostatic mechanisms are operative  in the
       embryo and fetus."

Therefore, an important component of the research program must be to  understand  when the
homeostasis  border is crossed, and how  this changes  as  a function of life  stage and/or
reproductive strategy.  In terms of ecological risk assessment, adverse effects are most often
defined in the context of decreased  populations and, less frequently, by changes in community
structure.  Metrics considered at the  individual level that infer likely trends in population  dynamics
are most commonly related to survival, growth, and reproduction.  Thus, chemical exposures that
negatively affect these endpoints are considered adverse.  Unfortunately, endpoints such as
survival, growth, and reproduction are fairly generic, in that they typically  do not reflect specific
MOAs  (modes of action) in terms of impact on any particular endocrine system.  Endpoints that
do reflect MOA of concern generally occur at the suborganismal level, and often may not be
translated directly into adverse effects at the level of the individual. Yet,  changes in the status of
systems at the molecular and cellular levels can be highly effective indicators, not only of MOA,
but of  possible adverse effects at  higher levels of organization that may not be manifested
immediately.  Because of this, the need to understand the effects of EDCs at multiple levels of
biological organization is critical, particularly in terms of defining adverse effects as a function of
a specific MOA.
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                                                    ORD Research Plan for Endocrine Disrupters

       Organisms seldom, if ever, actually encounter individual endocrine disrupting chemicals
in the environment, especially because of the potential for some chemicals to be persistent and
to bioaccumulate. In the development of specific research activities contained in the next section,
specific attention is given to the need to address the impacts of real-world situations in terms of
simultaneous (or sequential) environmental exposures to multiple EDCs. While this is noted in only
a single issue,  it should be emphasized that the concern for mixtures transcends virtually every
other activity in this research plan.

       Available measures of effects, measures of exposure, and measures of organisms and
ecosystem characteristics  for ecological risk assessment  need to be adapted to classes of
organisms  that  have  received   little   attention in  terms  of  traditional   toxicity  test
methods/approaches, such as amphibians, non-teleostfish, passerine birds, etc. Two objectives
are addressed  here: 1) better development of a comparative endocrinology/toxicology database,
and 2) better definition of baseline conditions for general processes and specific endocrine
function. Withoutthese, the usefulness of comparative endocrinology for assessing the ecological
risk of EDCs is significantly decreased.  To characterize the relative risks of EDCs from an
ecological perspective, it is necessary that the data collected have a high degree of consistency.
This  becomes  critical in terms of coordinating  existing monitoring programs so that biological
endpoints should include effects that indicate the impact of EDCs on individuals and populations,
and chemical characterization should include those xenobiotics suspected to exert toxicity through
endocrine disruption.  Moreover, measurements made across different monitoring efforts should
overlap. This type of coordination is not necessarily a research issue, but is very important from
the standpoint of a coherent approach to risk assessment and management decisions concerning
EDCs.

       If future health effects and exposure studies conclude that humans and the ecosystem  are
at significant risk due to exposure to EDCs, research on how best to lower or eliminate the risk will
be needed. This research should be directed at managing the risks associated with high exposure
pathways.  First, a survey should be conducted to characterize the important types of locations
or industrial processes where EDCs are released into the environment. For example, the majority
of the mass of EDCs may enter the environment via pesticide use in agriculture, or via wastewater
effluents from certain types of chemical industries. Second, unreasonable risk must be reduced
through various risk-management tools, many of which must be developed or fine tuned for EDCs.
For example, much of the risk may be associated with high concentrations of EDCs at hazardous
waste sites, such as in soils at Superfund sites, or in contaminated sediments. Risk-management
research associated with this scenario should concentrate on effective means of destroying or
containing EDCs at these sites.  Alternatively, much of the risk associated with  EDCs may be
linked to exposure associated with chemical plants where the use of or production of EDCs result
in exposure to  workers or the neighboring ecosystem.  In this case, risk-management research
should focus on engineered controls to minimize  exposure to workers and pollution-prevention
strategies to reduce the use or production of EDCs.

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                                                    ORD Research Plan for Endocrine Disrupters

IV. RESEARCH APPROACH AND ACTIVITIES

       Within this Chapter, specific research projects for biological effects and exposure research
have been organized following the matrix developed for endocrine disruption in the ORD Strategic
Plan (Appendix III). To provide a firmer basis for risk characterization, a third category, "Linkage
of Exposure and Biological Effects," was formulated to emphasize the critical need to integrate
these main components of the research program.  In many cases, the biological effects research
cuts across human and  ecological  research  problems,  and a coordinated,  interdisciplinary
approach is required. For example, EFF.1.1 (QSAR [Quantitative Structure-Activity Relationships]
Models of EDC Modes of Action) is targeted at providing tools of equal utility for predicting health
and ecological effects, as well  as the targeting of exposure assessment efforts.  Neither the
issues nor subissues are presented in priority order.

       For each "issue" or activity, a brief description, priority (high, medium or low, plus a priority
score assigned by the planning committee (see below), and  focus of the research (health,
ecological, exposure, or some combination) is provided. To place the activities into a hypothesis-
oriented context, each  issue was evaluated according to which of the nine overarching questions
stated in the Introduction  it addressed. This crosswalk (Appendix IV) clearly demonstrates the
areas of greatest uncertainty in our understanding of endocrine disruption. Two questions are the
predominant  driving  forces  (What  effects  are occurring in  exposed human  and wildlife
populations?  and  How and  to what degree are humans and wildlife populations exposed to
EDCs?).    The  need  to  identify chemical classes of concern,  develop extrapolation  tools,
understand the effects of multiple exposures and understand the sources of exposure are most
evident as secondary questions addressed by the issues. They illustrate the extent to which these
questions transcend many of the proposed activities. A time line in which individual issues should
be addressed is presented in Appendix Va-c, while the derivation of the overall  priority and priority
score is contained in Appendix VI. The priority score was based on the evaluation of each issue
against five major ranking criteria (Programmatic Relevance, Magnitude of Biological  Concern,
Potential Impact of Outputs; Sequencing of the  Research, and Feasibility of Technical Success)
as judged on a scale of 1  (most important) to 3 (less important) by members of the planning
committee. The  priority score is a non-weighted sum  of all ranks on all factors, and is adjusted
such that the issue with the lowest score (highest overall priority) received a value of 1.

       Throughout the reviews of this research plan, a number of lower priority items were
eliminated, leaving a high proportion of issues ranked "high." Although these issues are all within
the mission of ORD, the resources to successfully address all of them are unlikely to be available.
Hence, the individual Laboratories and Centers will be need to be selective when developing the
actual implementation  plans.  The most critical  uncertainties lie in determining whether humans
and wildlife populations are  being impacted by levels of endocrine disrupters  in the ambient
environment and in determining the sources of those exposures. Appendix VII arrays the EDC
projects according to the risk assessment paradigm and is consistent with presentation under the
Government Performance and Results Act (GPRA).  GPRA requires each  federal agency to
submit, by September 30, 1997, to the Office of Management and Budget and Congress a five-
year strategic plan. The plan  was required to include:

       •      a comprehensive mission statement.
       •      general goals and objectives, including outcome-related goals and objectives.
       •      a description of how the goals and objectives are to be achieved.
       •      a description of the program evaluations used in establishing or revising general
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                                                    ORD Research Plan for Endocrine Disrupters

              goals and objectives.

       Each agency is also required to submit a performance plan covering each program activity
set forth in the Agency's budget, which must be consistent with the strategic plan. ORD's research
on endocrine disrupters falls under EPA's "Goal 8: Sound Science, Improved Understanding of
Environmental Risk, and Greater Innovation to Address Environmental Problems.  Objective 3:
Emerging Risk Issues. Subobjective 3.2: Endocrine Disrupters."
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                                                   ORD Research Plan for Endocrine Disrupters

      BIOLOGICAL EFFECTS STUDIES:

       Research on the pathogenesis of EDC-induced adverse health effects includes studies
to identify EDCs, describe dose response relationships,  and evaluate the impact of EDCs on
developmental, reproductive, immune, neurobehavioral, and endocrine system functions in young
and mature organisms.  Studies that examine the latent effects of EDCs following exposure during
a critical life stage should be of particular focus. Approaches for obtaining this information include
studies of humans, laboratory animals, and wildlife (including invertebrate, fish, amphibian, reptile,
avian, and mammalian species) exposed to suspected  EDCs.  The broad objectives of the
research plan to evaluate the ecological risk of EDCs are twofold: 1) determine their risk relative
to other stressors on populations and communities, both from a prospective and retrospective
standpoint; and 2) develop or modify methods  for testing and evaluating chemicals and
environmental samples to ensure that those exerting toxicity through specific endocrine axes will
be characterized. Both objectives require a reduction in uncertainty in prediction of risk across
levels of biological organization, including better linkage of measurement and  assessment
endpoints. They also require an increased understanding of processes and species at risk,
including an understanding of modes of action. General research needs and specific research
approaches necessary to meet these needs are listed below.  It should be noted that the specific
research approaches usually address more than one of the general issues identified  below, much
of the necessary research can (or should be) interrelated.
EFFECTS ISSUE 1. DETERMINE THE CLASSES OF CHEMICALS THAT ACT AS EDCS AND
THEIR POTENCIES.
EFF.1.1      DEVELOPMENT OF IN VITRO AND IN VIVO SCREEN ING METHODS AN D QSAR
             MODELS OF EDC MODES OF ACTION, FOR EXAMPLE, RECEPTOR BINDING,
             GENE   ACTIVATION   AND  ENZYME  INHIBITION    ENCOMPASSING
             VERTEBRATE AND INVERTEBRATES.

             Short-term in vitro and in vivo methods need to be developed to screen for EDCs
             with specific modes of action (MOAs), including alterations in hormone levels and
             induction of specific ligand inducible genes (e.g., vitellogenin). The results of these
             assays should be calibrated against effects on integrated processes (development,
             reproduction)  at the  level of the individual.   Quantitative  structure-activity
             relationship (QSARs) models need to be developed for EDCs for key events such
             as receptor-binding of xenobiotics, transcriptional activation, and posttranscriptional
             events  to serve as screening tools for  evaluating  the chemical universe.
             Endocrine-mediated processes related to reproduction and development should be
             highlighted. In addition  to being useful tools for prospective risk analyses, QSAR
             models can provide critical insights in retrospective evaluations of risk.   For
             toxicants that are metabolically activated, QSAR models would allow one to identify
             the potentially active metabolite for in vitro testing.

             High Priority (Adjusted Score from Appendix Vl=1), Human Health and Ecological
             Focus
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                                                ORD Research Plan for Endocrine Disrupters

EFFECTS ISSUE 2. EVALUA TE CURRENT TESTING AND MONITORING PROCEDURES FOR
ADEQUACY OF ASSESSMENT OF EDC EFFECTS.
EFF.2.1      DEVELOPMENT, STANDARDIZATION, AND UTILITYOF IN VITRO AND IN VIVO
            TEST METHODS TO IDENTIFY ENDOCRINE DISRUPTING ACTIVITY.

            Present tests to assess toxicity provide little information on the MOA of a chemical
            or the potential to produce latent effects after developmental exposure. For human
            health effects, the proposed improvements to the EPA multi-generational test will
            provide improved EDC detection for hazard identification and dose-response, but
            these tests are expensive and take years to complete. However, multi-generational
            tests are seldom used for ecological risk assessment. Hence, short-term tests are
            also needed to detect EDC activity. Efforts should focus on those MOAs known
            to be exhibited by relevant environmental chemicals, including estrogenicity, anti-
            androgenicity, Ah-receptor binding, and anti-thyroidal activity. In addition to initial
            ligand receptor binding, endpoints should include EDC-induced changes in normal
            endocrine-mediated transcriptional activation.   Due to EPA's Congressional
            mandate and the direct regulatory implications of this area, research planning
            should be done in coordination with EPA regulatory program offices.

            High priority (Adjusted Score from Appendix Vl=13), Human and Ecological Focus
EFFECTS ISSUE 3.  DETERMINE THE SHAPES OF THE DOSE-RESPONSE CURVES FOR
EDCs AT RELEVANT EXPOSURES AND  THE  TISSUE  LEVELS ASSOCIATED  WITH
ADVERSE EFFECTS.
EFF.3.1      MODE-OF-ACTION STUDIES FOR DEVELOPMENTAL AND REPRODUCTIVE,
            CENTRAL  NERVOUS SYSTEM,  AND  NEUROENDOCRINE TOXICITY  IN
            LABORATORY ANIMALS FOLLOWING DEVELOPMENTAL EXPOSURES.

            A  more complete understanding of specific chemical  MOA  is required for
            between-chemical and between-species extrapolation. Since many EDCs elicit
            toxicity through receptor-based interactions, these chemicals particularly should be
            amenable to MOA research. Other endocrine disrupting agents may act through
            membrane receptors, enzyme alterations,  and other non-nuclear receptor-based
            pathways.   Research in this area should  be coupled with QSAR analyses and
            comparative endocrinology and toxicology. The emphasis of this research should
            be on mechanisms that operate in the low end of the dose-response curve and the
            development of quantitative descriptions of rate limiting steps for later incorporation
            into formal BBDR (Biologically Based Dose-Response) Models.

            High Priority (Adjusted Score from Appendix Vl=23); Human and Ecological Focus
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                                               ORD Research Plan for Endocrine Disrupters

EFF.3.2      DEVELOPMENTAL AND ACUTE EFFECTS OF EDCs ON IMMUNE FUNCTION
            OF LABORATORY ANIMALS.

            Numerous reports  of immune alterations have been reported in EDC-exposed
            wildlife populations and children. Studies of EDCs in animal models are needed
            to verify these effects under controlled conditions.

            High/Medium  Priority (Adjusted Score  from Appendix Vl=27);  Human  and
            Ecological Focus
EFF.3.3      STUDIES USING ANIMAL MODELS OF SUSPECTED EDC-INDUCED HUMAN
            DISEASES SUCH AS REDUCTIONS IN  SPERM COUNTS, AND INCREASED
            INCIDENCES OF  INFERTILITY,  TESTICULAR  CANCER,  HYPOSPADIAS,
            ENDOMETRIOSIS, BREAST CANCER AND PROSTATE CANCER.

            For several of the aforementioned conditions, adequate animal models have not
            been developed and validated. Validated animal models can greatly enhance the
            process of identifying the potential of EDCs to produce diseases in the human
            population.   Specifically, research is needed on models of testicular  cancer,
            endometriosis, breast cancer, and benign prostatic hyperplasia and prostate
            cancer.  Once these  animal models are developed, they can be used to test
            hypotheses that low, environmentally relevant doses of EDCs can induce similar
            conditions in  humans.

            High priority (Adjusted Score from Appendix Vl=10); Human Focus
EFF.3.4      PHARMACOKINETIC  STUDIES  OF  HIGHLY  RELEVANT  EDCs  WITH
            PARTICULAR  FOCUS ON CRITICAL  PERIODS OF DEVELOPMENT OF
            REPRODUCTIVE, NEUROENDOCRINE AND IMMUNE SYSTEMS.

            The lack of validated pharmacokinetic (PK) models to predict transplacental and
            breast milk deposition of EDCs in fetal and neonatal target organs limits our ability
            to determine when adverse concentrations would result as a consequence of
            chronic  and  acute maternal exposures.  We anticipate that PK  models for
            developmental  EDC exposure can be readily developed and would  provide
            extremely  useful  predictive  information  for characterizing  dose-response
            relationships on the basis of delivered dose to the target tissue.

            High Priority (Adjusted  Score from Appendix Vl=24); Human Focus
EFF.3.5      DEVELOPMENT OF BIOLOGICALLY BASED DOSE-RESPONSE MODELS FOR
            HIGHLY RELEVANT EDCs WITH PARTICULAR FOCUS ON CRITICAL PERIODS
            OF DEVELOPMENT OF REPRODUCTIVE AND IMMUNE SYSTEMS AND THE
            CENTRAL NERVOUS SYSTEM.

            Understanding the various steps in the pathogenesis of adverse effects is key to
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                                                  ORD Research Plan for Endocrine Disrupters

 reducing the uncertainties in extrapolation of animal test data to humans. BBDR studies should
be linked to the development of PK models described in EFF.3.4.  Incorporating modes of action
in quantitative risk models is essential to understanding the risks of low dose exposures, which
should be the primary area of emphasis for this research area. Although these models are of high
relevance and great potential impact, they, are also extremely complex to construct and represent
relatively high risk research projects.

             High/Medium Priority (Adjusted Score from Appendix Vl=34); Human Focus
EFF.3.6      STUDIES ON THE MODES OF ACTION OF EDCs ON CELLULAR, MOLECULAR,
             NEUROENDOCRINE CENTRAL NERVOUS SYSTEM FUNCTION IN PUBERTAL
             AND ADULT LABORATORY RODENTS.

             Steroid and thyroid hormones are important in  the  regulation of puberty  in
             developing animals and in modulating central nervous system function in adults.
             Therefore, these processes potentially are sensitive to alteration by EDCs, and
             research is  needed to characterize the extent of the impact relative to  other
             endpoints of known responsiveness.

             Medium priority (Adjusted Score from Appendix Vl=37); Human Focus
EFFECTS ISSUE 4.  DESCRIBE THE NORMAL ENDOCRINE PROFILES IN  WILDLIFE
SPECIES.

      Little  is known about  normal variability in different wildlife species relative to most
endocrine systems or endocrine-mediated endpoints, such as temporal  variations in basic
hormonal profiles and developmental and fecundity rates.  A recent example of how this  can be
a problem arose in a study in which apparent differences in plasma sex steroids in fish collected
from several field locations were reported, but it was unclear whether these differences were due
to site-specific (e.g., contaminant) factors or normal temporal variations in the test species (e.g.,
correlated with reproductive cycles). Data of this type can be collected in routine (field) monitoring
experiments, or in  more focused comparative physiology and toxicology studies. Because
endocrine processes are highly  conserved across species,  particularly across vertebrates,
comparative studies are important to help extrapolate outcomes based on MOA determinations.
For example, it would be important to establish whether a chemical that causes estrogenic effects
in one species also causes them in other species.  In  fact, this is a major (but unproven)
supposition in the design of screening assays for EDCs by EDSTAC. Thus, it is important that the
technical underpinnings of the assumption of commonality  in response be assessed fully across
species.  Although basic endocrinology research  is funded to some extent by other federal
agencies, this type of research generally has not been systematic enough to serve as a basis for
the type extrapolations needed by EPA to deal with EDCs. This does highlight, however, the need
for continued coordination among federal agencies with respect to EDC-related research.
EFF.4.1      DEFINITION   OF  "BASELINE"   ENDOCRINE   STATUS   IN   WILDLIFE
             POPULATIONS AND THEIR LABORATORY SURROGATES.
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                                                   ORD Research Plan for Endocrine Disrupters

             At present, we are uncertain about the normal values of many EDC-influenced
             factors in  fish and wildlife  populations.   These  include elements such  as
             intracellular receptor numbers, circulating hormone concentrations, developmental
             rates, reproductive capacity, population sex rations, and age structures. This type
             of information is critical not only for extrapolation in prospective risk assessments,
             but for effective monitoring in retrospective analyses.

             High Priority (Adjusted Score from Appendix Vl=26), Ecological Focus
EFF.4.2      STUDIES IN COMPARATIVE ENDOCRINOLOGY AND TOXICOLOGY.

             Basic endocrine system structure and function can be remarkably well-conserved
             across phyla. However, many key and potentially sensitive species have not been
             evaluated with respect to  endocrine function, particularly  from a toxicology
             perspective. Thus, baseline research on specific endocrine systems  related to
             reproduction, development, and immunocompetence across several representative
             classes of animals could reduce uncertainty associated with among species
             extrapolations. These types of studies should specifically include those organisms
             which historically have received little attention in terms of environmental toxicology,
             and/or are experiencing declines in populations. Part of this task would be to use
             laboratory studies to confirm EDC-related hypotheses generated from field studies.
             The key for using comparative endocrinology and toxicology data to extrapolate
             among  species will be the concurrent development of biologically based dose-
             response  and PB-TK models; this modeling perspective is needed in recognition
             of the fact that it is impossible  to test every permutation of chemical and species.

             Medium Priority (Adjusted Score from Appendix Vl=33), Ecological Focus
EFF.4.3      STUDIES ON THE ROLE OF HORMONES IN SEXUAL DIFFERENTIATION OF
             NONMAMMALIAN SPECIES AND THE EFFECTS OF EDCs ON THIS PROCESS
             IN INVERTEBRATE, AVIAN, REPTILIAN, AMPHIBIAN, AND FISH SPECIES.

             Numerous alterations of reproduction have been attributed to EDC exposure during
             development of wildlife species.  It is often impossible to determine the biological
             plausibility of these speculations because the hormonal regulations  of sexual
             differentiation are not completely, or are poorly understood in nonmammalian
             vertebrates.

             Medium Priority (Adjusted Score from Appendix Vl=36); Ecological Focus
EFFECTS ISSUE  5.     EXTRAPOLATE  EFFECTS AT THE  INDIVIDUAL LEVEL  TO
POPULATIONS FOR FISH WILDLIFE SPECIES.

      There is a need to identify and validate measurement endpoints that are indicative of the
effects of EDCs at individual and sub-organismal levels and at the level of populations and
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                                                    ORD Research Plan for Endocrine Disrupters

communities. Linkages among proposed measurement endpoints are uncertain. For example,
at the level of the  individual,  the impact of induction of vitellogenin  in male fish exposed to
estrogenic  chemicals  on  reproductive  success  is not  known.  Similarly,  impacts  on
endocrine-mediated processes at the level  of the individual can be  difficult to translate into
population-level effects. This linkage also is key to defining relationships between measurement
and assessment endpoints in ecological risk assessments. In this plan, we identify general criteria
to consider in terms of species  selection (e.g., those that have received little attention in the past,
but might be experiencing population-level declines). However, these recommendations should
be taken in  the context of  specific research issues.  Not all wildlife species can or will be
considered in terms of ecological research with EDCs; this is logistically impossible.  Therefore,
species will be selected to enable extrapolation of potential EDC effects across animal species
and classes.
EFF.5.1      BIOASSAYS FOR EVALUATING INTEGRATED EFFECTS.

             Many of the standard toxicity tests currently in use for regulatory activities such as
             product registration and monitoring environmental samples are inadequate for
             detecting some of the key reproductive, developmental, and immunological effects
             of EDCs.  Problems include use of species that are insensitive to specific EDCs,
             lack of exposure during critical windows of sensitivity, and failure to consider latent
             or EDC-specific effects. These tests should be modified where possible and new
             assays developed as needed. When selecting species or endpoints for assessing
             effects of EDCs,  care should be taken to ensure that the information gathered is
             useful for predicting population-level effects.  This effort should be coordinated with
             activities covered under EFF.5.2 and LNK.2.2 so that as measurement endpoints
             are developed to the level of the individual, they are then evaluated at the
             population/community levels.

             High Priority (Adjusted Score from Appendix Vl=26); Ecological Focus
EFF.5.2      EVALUATION OF EFFECTS AT POPULATION AND COMMUNITY
             LEVELS.

             It is necessary to translate measurement endpoints collected at lower levels of
             biological  organization  into impacts at population  and, if possible, community
             levels. Moreover, there may be measurement endpoints sensitive to the effects of
             EDCs both at population (e.g., sex ratios) and community (e.g., guild structure)
             levels. In either case, further research is needed to quantify EDC impacts at these
             higher levels of organization.  Experimental systems that can prove particularly
             useful include microcosms and  mesocosms.  Although EPA no longer utilizes
             mesocosm data as part of the pesticide registration process, mesocosms are
             useful in the context of specific tests of experimental  hypotheses.  The  use of
             mesocosms to test EDC effects on populations  in a true environmental setting
             offers a powerful and cost-effective alternative to full-scale field studies.  (Note that
             as EFF.5.1 proceeds, this would become a high priority).

             High/Medium  Priority (Adjusted  Score from  Appendix Vl=22); Ecological and
             Exposure  Focus
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                                                   ORD Research Plan for Endocrine Disrupters

EFF.5.3      DETERMINATION OF SENTINEL SPECIES

             Appropriate sentinel species for monitoring need to be identified. Selection of
             sentinel or keystone species is highly context-specific, so research planning should
             not be  based upon selection of any particular class/species of animals, but on
             "problem" chemicals and sites or toxicological endpoints and issues.  From that,
             appropriate animal models for research can be identified. Considerations for their
             selection should include: 1) representation of different life history strategies; 2)
             species vagility with respect to exposure distribution; 3) representation of multiple
             taxonomic and trophic levels; 4) manipulability of species in laboratory tests; 5)
             availability of baseline  information;  and 6) the  degree of  distribution  (i.e.,
             widespread or local) of a species. Surrogate (non-endangered, noncommercial)
             species for study need to be  identified  for which  effects can  be related to
             endangered or commercially important species.

             High priority (Adjusted Score from Appendix Vl=26); Ecological Focus
EFFECTS ISSUE 6.  CHARACTERIZE THE EFFECTS OF EXPOSURE TO MULTIPLE EDCs.
EFF.6.1      SYSTEMATIC  STUDIES  OF  THE  INTERACTIONS  OF  LOW,
             RELEVANT DOSAGE LEVELS OF  MIXTURES OF RELEVANT
             EDCs.

             In most cases, humans and other organisms are exposed to relatively low doses
             of mixtures of chemicals with EDC activity.  It is unclear how such mixtures will
             behave. While some scientists have reported that effects will typically be additive
             in nature, others have reported that estrogens and anti-estrogens will cancel one
             another out, while some other studies indicate that EDCs act synergistically. While
             this is the only issue devoted exclusively to the study of mixtures, the issue of
             multiple exposures impacts  on many of the other issues identified in this plan
             (Appendix IV).

             High Priority (Adjusted Score from Appendix Vl=16); Human and Ecological Focus
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                                                  ORD Research Plan for Endocrine Disrupters

      EXPOSURE ASSESSMENT STUDIES:

      The pathways between  source  and exposure to  EDCs are  complex.   Many of the
suspected EDC's studied are organic compounds or organic forms of a few heavy metals that
persist, bioaccumulate, and biomagnify in the food chain.  Knowledge of the nature of these
factors is basic to predicting future exposures and the efficacy of exposure prevention strategies.
Forexample, slightvariations in chemical form and physicochemical characteristics (e.g., planarity,
isomerization, and polarity), may manifest themselves in various ways that affect exposure (e.g.,
differences in transport and routes of exposure, increased or decreased bioavailability, changes
in exposure pathways, potential for atmospheric and hydrological transformation, and fate).

      Another major challenge is the need to understand complex exposure patterns, rather than
simple net annual exposure.  As discussed under Biological Effects Studies, there are certain to
be windows of vulnerability to exposure because of temporal and seasonal patterns of endocrine
functions.  For example,  exposure  to one EDC during an animal's mating season may  have
significant effects, whereas for another EDC,  exposure during gestation may be more crucial.
Therefore, ORD will conduct exposure research of endocrine disrupting substances within the
Agency's risk assessment framework, and will explore methods and  models to measure and
predict exposure to these substances.

      ORD's exposure research will emphasize three areas. The first involves better physico-
chemical characterization of a few known or highly suspect EDCs to obtain a better near-term
understanding of the potential effects of chemicals of current concern.  The second area is
developing pathway models (e.g., compartmental transport,  fate, or transformation) for chemicals
that are likely to be endocrine disrupters.  In both of these areas, existing information in the public
literature or in EPA data files will be  evaluated to establish current capabilities and identify data
gaps and uncertainties. The third area is to reduce uncertainties in the flux of EDCs in and out
of sediments, a major exposure source for many bioaccumulative compounds.
EXPOSURE ISSUE 1: DEVELOP A FRAMEWORK TO CHARACTERIZE, DIAGNOSE, AND
PREDICT ECOLOGICAL AND HUMAN EXPOSURE TO EDCs.
EXP.1.1      IDENTIFICATION AND EVALUATION OF CLASSES OF SUSPECTED EDCs TO
             WHICH HUMANS AND ECOSYSTEMS ARE LIKELY TO BE EXPOSED IN THE
             ENVIRONMENT.

             The  physico-chemical attributes  of  substances associated  with  endocrine
             disruption, which occur with suspect EDCs in the environment, or that  have
             transport, transformation, and fate characteristics similar to EDCs need to  be
             systematically characterized. Once distinguishing chemical characteristics have
             been identified for suspected EDCs,  generic categories of attributes  may  be
             defined and used to screen new or previously unsuspected substances for EDC
             potential. Definition of generic categories would also facilitate the development of
             EDC scenarios and uncertainty distributions for subsequent exposure modeling
             research. Attribute categories will be updated as additional information becomes
             available under Exposure Issue 3 and Effects Issue 1.
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             High Priority (Adjusted Score from Appendix Vl=9); Exposure Focus
EXP.1.2      DEVELOP, SELECT, AND APPLY COMPARTMENTAL MODELS TO ENHANCE
             UNDERSTANDING OF HOW EDCs BEHAVE IN ENVIRONMENTAL MEDIA AND
             TO PREDICT EDC EXPOSURES.

             The environmental media through which EDCs are transported can be treated as
             compartments in mathematical models. Research is needed to identify the major
             compartments through which EDCs move, change, accumulate, and reside. The
             models will then account for the persistence, bioaccumulation, bioconcentration,
             and biomagnification of chemicals within each environmental medium according
             to the physicochemical properties identified in EXP.1.1. Models that diagnose or
             predict the movement of EDCs from source to receptor will be applied, adapted, or
             developed  to simulate  EDC movement  and change  in the  environment.
             Geographic scale will play a crucial role in model selection. There may be a need
             for predictive capability on the micro scale (e.g., occupational, residential), field
             scale (e.g., production plant emissions), regional scale (e.g., farm applications
             impacting watersheds) and global scale (e.g., long-range transport with exposure
             at remote sites).  For human exposure, the initial focus should be on the micro-
             scale, whereas for ecosystems, regional models are needed.

             High Priority (Adjusted Score from Appendix Vl=28); Exposure Focus
EXPOSURE ISSUE 2: PROVIDE ADEQUATE (SENSITIVE, RELIABLE, AND INEXPENSIVE)
TOOLS TO ESTIMATE EXPOSURE TO EDCs.

      The Science Advisory Board's 1995 report to EPA, Beyond the Horizon: Using Foresight
to Protect the Environmental Future said, "EPA should attempt to identify, monitor, and analyze
the most potentially serious of these unconventional stressors, and then assess their adverse
effects on  human  health  and  ecological  systems."   A major  shortcoming of analytical
environmental chemistry is its inability to monitor for non-volatile, non-extractable, or thermally
labile (unconventional) organic pollutants, which often may be the most prevalent compounds in
many environmental samples. A true assessment of ecological and human risk can be obtained
only with the ability to characterize and monitor this unknown fraction. Very few methods address
the extraction, characterization, and identification of EDCs in tissue, either plant or animal, and
this may very well end up being the limitation of most of the existing methodologies.  An initial
subelement under this Issue will be to gain a better understanding of our ability to collect, prepare,
and analyze environmental and biological samples for a few EDCs selected based upon toxicity
and bioavailability to select organisms, and presence and persistence in the environment.
EXP.2.1      IMPROVED UNDERSTANDING OF TRANSPORT, TRANSFORMATION, AND
             FATE OF EDCs IN ENVIRONMENTAL MEDIA

             Many of the suspect EDCs identified to-date are low-solubility, neutral organic
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                                                   ORD Research Plan for Endocrine Disrupters

             compounds that  are  highly sorbed to organic  carbon phases  of sediments,
             suspended particles in the water column, airborne particulate matter, and soil. While
             currently available predictive tools  (based on  hydrophobic solution theory) are
             reliable for estimating movement and change of some EDCs between the sediment
             and water column, comparable  tools for estimating  kinetics  of  sorption  and
             desorption processes are lacking. Research is needed to develop models to predict
             these processes for ionizable EDCs undervaluing pH and ionic strength conditions.
             In  addition to sorption  kinetics,  the  biological relevance of EDCs should be
             understood better.  This includes  the interactions of microbial, chemical,  and
             physical processes. The interplay of theses processes should be an overarching
             theme for any study of fate in the environment.  Transformation  processes of
             significant  relevance  to EDCs include the  action of chemical and  biological
             reductants in anaerobic and low dissolved  oxygen environments, such as an
             assessment of the role of sulfur-based nucleophiles in reducing the sulfur in the
             herbicide atrazine, and the passage of EDCs among abiotic and biotic systems,
             such as sediment flora and gut, gill,  and other benthic fish tissues.

             High Priority (Adjusted Score from Appendix Vl=28); Exposure and Ecological Focus
EXP.2.2      DEVELOP MEASUREMENT METHODS FOR EDCs IN ANIMAL AND  PLANT
             TISSUE AND ENVIRONMENTAL COMPARTMENTS

             To understand the risks of EDCs,  improved field  methods are necessary to
             characterize their fate and transport.  Methodologies must be developed and used
             to optimize monitoring and analytical throughput in all environmental media, with
             high sensitivity.  For example, piscine populations exposed to sewage discharge
             plumes have shown intersexuality.  However, causality has not been established.
             To improve the weight of evidence, research  is  needed to improve  sample
             extraction methods, extract preconcentration, chromatographic separation, and
             analyte detection.

             High Priority (Adjusted Score from Appendix Vl=10); Exposure and Ecological Focus
EXP.2.3      DEVELOP EXPOSURE SCREENING TOOLS AND BIOMARKERS FOR EDCs.

             EDC concentrations in human and wildlife tissues and other biological media must
             be compared to concentrations in the abiotic environment.  Promising research has
             begun in the development of probes for gene expression resulting from EDC binding
             to hormone receptors in fish and wildlife.  Exposures of organisms to EDCs can be
             detected with good sensitivity by probing for changes in gene expression brought
             on by hormone receptor binding.  Biomarkers of exposure are needed to screen
             ecosystems for exposures, improve exposure estimates in future epidemiological
             studies, and assist in developing and verifying human  and  ecosystem exposure
             models. These techniques should aid in identifying and characterizing sources and
             intensity of exposures.   This screening and biomarker research will entail
             collaboration with the pharmacokinetic research described in the Effects Section.,
             and the results will be incorporated into the biotic components of exposure models
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                                                  ORD Research Plan for Endocrine Disrupters

             developed under EXP.1.2.

             High Priority (Adjusted Score from Appendix Vl=21); Exposure and Ecological Focus
EXPOSURE ISSUE 3: DETERMINE THE TOTAL ECOSYSTEM AND HUMAN EXPOSURES TO
EDCs OF CONCERN.

      The research on exposure described previously will increase our understanding of the
potential risks from EDCs substantially.  It will also identify and prioritize targeted uncertainties
requiring further study.  For example, the compartmental modeling studies under Exposure Issue
1 may indicate that, for chemicals having certain physico-chemical properties, air-to-watertransport
is the predominant factor in enhancing exposures. If so, more intense research would be needed
on atmospheric phase equilibria  and deposition of these  compounds.   Exposure to other
compounds may be more influenced by microbes in sediments, suggesting another area for more
intense research, but not for others.  On a broader scale, effects research  may identify a high
potency EDC that also potentially has a widespread exposure. This may necessitate an exposure
or epidemiological study of this EDC. Gathering reliable data from the field is  necessary for direct
assessment of EDC exposure, for development and verification of predictive and diagnostic
exposure models, and for priority setting for additional study of vulnerable or contaminated sites.
EXP.3.1      STUDY MATERNAL/INTERGENERATIONAL TRANSFER OF EDCs.

             For endocrine disrupter MOAs,  certain stages of development in humans and
             wildlife present windows of exposure, where the organism is particularly vulnerable
             to hormonal disruption.  Depending upon their reproductive strategy, developing
             organisms may be exposed directly to EDCs, or may receive exposure via the egg
             yolk, or may be exposed via transplacental and lactational transfer. In most cases,
             there is  a dearth  of  information  regarding  the  magnitudes of exposure that
             developing  invertebrates,  amphibia, fish, reptiles, birds,  and mammals face
             concerning EDCs.  The uptake, storage and magnification of EDCs in the parental
             organisms and the amount of EDCs  transferred to the embryonic and neonatal
             animals should be studied. Selection of animal models should be based upon
             reproductive or physiological characteristics, such as placental mammals, life cycle,
             developmental stage at hatching, and sex determination mechanisms.  The results
             will be incorporated into the exposure model  that include biotic compartments of
             exposure models developed under the Exposure Issue.

             Medium Priority (Adjusted Score from Appendix Vl=35); Exposure, Human Health
             and Ecological Focus
EXP.3.2      STUDY BIOACCUMULATION OF EDCs IN FOOD WEBS.

             There is a need for field studies to measure available human and wildlife tissue and
             other biological  media  for  EDCs  to  compare  concentrations  in  the  abiotic
             environment to concentrations in the food chain. The use of the top carnivores and
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                                                   ORD Research Plan for Endocrine Disrupters

              higher level  species  does  not  obviate  the  need  for  the  study  of
             bioavailability,   and  concentrations  of EDCs in lower trophic  levels.
             However, it provides a framework for the study of the entire ecosystem, and
             baseline data regarding the build up on EDCs. These considerations will be
             incorporated into the pilot studies described  in the next section.  This task
             can provide data on EDC levels in wildlife  tissues that can serve as an
             ecological counterpart to the human data collected in  EXP.3.3.

             Medium Priority (Adjusted Score from Appendix Vl=34); Exposure and Ecological
             Focus
EXP.3.3      POPULATION-BASED DISTRIBUTIONS OF EDC EXPOSURES

             There is a need to determine the distribution of exposures to endocrine disrupting
             chemicals in the environment to evaluate the proportion of the general population
             that may be at risk to adverse health effects.  Consideration should be given to
             ensuring that existing programs such as NHANES (National Health and Nutrition
             Survey) include monitoring of the important classes of EDCs such as phthalates,
             phenols, phytoestrogens, organochlorines, and other pesticides and herbicides.
             The availability of such information would tell us whether the general population is
             exposed and whether exposure characteristics differ among subpopulations.

             High Priority (Adjusted Score from Appendix Vl=22),  Exposure and Human Focus
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                                                  ORD Research Plan for Endocrine Disrupters

      LINKING BIOLOGICAL EFFECTS, EXPOSURE AND RISK MANAGEMENT RESEARCH:

      One of the potential strengths of the research program within ORD is to bridge the gaps
between effects, exposure, and risk management-based research through interaction of the various
centers and laboratories.  Since the extent of the need for risk management research is unknown
at this time, the majority of this section discusses a linked effects and exposure research program.

      We have attempted to formulate an integrative effects and exposure program by designing
project areas in which both types of research must work together to accomplish the objectives. We
also introduce risk reduction issues in a general sense. The importance of these projects are not
in accordance with their position at the conclusion of the Research Issues Section because the
groundwork on specific issues relevant to effects and exposure  research had to precede this
section for full comprehension of the scope of required coordinated effort. The efforts to address
the effects and  exposure issues presented  in  this research plan must  be implemented
comprehensively. The research results must be linked to ensure that the biological responses in
human and wildlife populations can be compared to environmental concentrations and pathway
estimates from exposure  models and  field investigations.  In some  instances, the scope of the
research necessitates extramural expertise to augment our research capabilities or assume primary
research responsibilities (through the grants program).

       Data bases that contain information about EDCs need to be identified and reviewed, and
methods are needed to improve coordination, reliability, and access  by the scientific  community.
EXP.1.1 and LNK.1.1 will first prioritize potential problem areas based upon exposure (elevated
concentrations of EDCs) or effects (organisms exhibiting responses possibly related to endocrine
disruption).  Reliable and standardized data  bases are vital in  testing effects and exposure
hypotheses and in validating the compartmental, exposure, and effects models. Compartmental
models and laboratory studies must be linked to field research through mechanism-based dose-
response models. Exposure levels observed  in the field will be used as  a basis for identifying
realistic dose ranges in laboratory experiments.

      As the EDC research program matures, it is likely that risk management research will need
to be added to the linked research activities. Already there is sufficient evidence to conclude that
some EDCs present unacceptable risk in limited situations. Ongoing and future health effects and
exposure studies may conclude there  is larger scale, unacceptable risk of exposure of EDCs to
humans and ecosystems.  Significant research on how best reduce the risk to acceptable levels
will be needed. This research should be directed at managing unacceptable risks associated with
high  exposure pathways.  General  risk management approaches that would need specific
development for EDCs include: (1) removal of high-mass sources of EDCs in the environment
through site remediation;  (2) pollution  prevention to minimize the use, release, or production of
EDCs; and (3) engineered controls to reduce exposures to humans and the ecosystem  to
acceptable levels when source removal and pollution prevention approaches are not suitable.
LINKAGE ISSUE 1.  INTEGRATE HUMAN AND ECOLOGICAL EFFECTS RESEARCH WITH
EXPOSURE RESEARCH WITHIN THE RISK ASSESSMENT PARADIGM.
LNK.1.1      ESTABLISH FRAMEWORKS FOR COMPREHENSIVE EDC INVESTIGATIONS
             AND ASSESSMENTS
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                                                    ORD Research Plan for Endocrine Disrupters

             The primary goal of this effort is to identify, characterize, prioritize, and assess the
             potential exposures and effects to selected suspect EDCs through a joint  effort of
             NHEERL, NERL, NRMRL, and NCEA.  On the assessment side, a framework will
             be developed to integrate experimental and observational data for both human
             health and ecological effects in order to conduct holistic risk assessment  for EDC
             MOAs.  This effort will consider how best to incorporate MOAs, multiple chemical
             exposure, critical life stages, criteria for adversity, dose-response relationships, and
             inter-species comparisons. Such tools will be needed as the knowledge  base on
             endocrine  disrupters  increases over the  next few years.  From a  review of the
             current state of knowledge and data bases for several suspect endocrine disrupters
             (i.e., physicochemical data, fate-and-transport information, anticipated human and
             ecological effects, and exposure), an initial risk characterization of a few chemicals
             within a specific class will be developed collaboratively.   A framework that
             characterizes potential exposure pathways and effects will be used to generate
             probability matrices that: (1)  identify potential routes of exposure and health
             outcomes; and (2) array suspected endocrine disrupters against potential exposure
             pathways and health outcomes.  Such efforts should facilitate the evaluation of
             causality of reported adverse health effects. This data base will also provide the
             basis for clearly identifying major gaps in both exposure and effects  relative to
             endocrine disrupters,  establish a strong linkage between the needs to identify and
             characterize source distributions, provide  the basis for prioritizing research efforts
             proposed  for assessing  exposures and effects identified  in integrated  field
             assessment (LNK.2.2), and provide a framework for integrated both exposure and
             effects results to develop appropriate risk assessment and  risk  management
             strategies.

             High Priority (Adjusted Score from Appendix Vl=24); Exposure, Ecological and
             Human Focus
LINKAGE ISSUE2. DETERMINE CLASSES AND CONCENTRATIONS OF EDCs ASSOCIATED
WITH OBSERVATIONS OF ENDOCRINE DISRUPTION.
LNK.2.1      EVALUATION OF EXISTING DATA AND CURRENT PROGRAMS.

             Efforts are needed to: (1) develop a data base of chemicals (and their effective
             concentrations) known to cause, or strongly suspected of causing, reproductive and
             developmental effects via an EDC related mechanism; (2) identify loading estimates
             for determining exposure to potential EDCs; (3) identify appropriate reference sites;
             and (4) factor loading estimates, geographic distribution, and life history traits in
             potential sensitivities of specific populations. These efforts will assist in hypothesis
             generation and identification of information gaps needed for implementation of the
             integrated studies described in other linkage projects. There is a good deal of
             archived biological and environmental chemistry data that could be used to identify
             hot spots/problem areas and species at risk.  Examples of existing monitoring
             programs in the U.S. that may be useful include EPA's Environmental Monitoring
             and Assessment Program (EMAP), the National Status and Trends Program (BEST)
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                                                   ORD Research Plan for Endocrine Disrupters

             of the NBS,  and the National Water Quality  Assessment Program (NAWQA)
             administered by the U.S. Geological Survey.  We need to improve our use and
             dissemination of existing exposure and effects data, as well as the use of specimen
             banking. Suitable historical control/reference data for assessment of effects must
             be identified,  data must be collected with a high degree of consistency, and effects
             of EDCs must be explored in individual organisms as well as populations.

             High Priority (Adjusted Score from Appendix Vl=29); Ecological and Exposure Focus
LNK.2.2      INTEGRATED EFFORTS ON WILDLIFE AT EDC-CONTAMINATED SITES.

             Coordinated effects and exposure measurements are needed for areas suspected
             to be contaminated with high concentrations of EDCs. Here, biomarker researchers
             can test screening tools,  in situ results can be compared to in vivo and in vitro
             findings, and biologically  plausible hypotheses (exposure and/or effects) can be
             evaluated. Several specific sites will be selected based upon strong weight of
             evidence that populations have been affected by exposure to EDCs.  This evidence
             can consist of ecological  epidemiology,  positive response or exposure screens,
             historical data (from LNK.1.1) suggesting that EDCs are present in  environmental
             media, or where fate models suggest a hot spot. An ecosystem approach should
             be adopted and multiple phylogenetic groups and trophic levels  should be studied
             at a given site. The site will be used to test and validate predictive, integrated
             models  that   utilize  structure-activity  relationships  (SAR),   toxico kinetics,
             bioenergetics, environmental chemistry, and population ecology, provide a means
             for testing effects and exposure screening tools, and will provide multimedia sample
             material foranalytical methods development (EXP.2.2). To provide all the necessary
             expertise, this would have to be a carefully coordinated intramural and extramural
             effort, with clear need for cooperative agreements rather than grants.

             High Priority  (Adjusted Score from Appendix Vl=14);  Ecological and  Exposure
             Focus
LNK.2.3      EXAMINE HUMAN POPULATIONS FOLLOWING DEVELOPMENTAL EXPOSURE
             TO  EDCs     FOR   ALTERATIONS  IN  CENTRAL   NERVOUS  SYSTEM,
             REPRODUCTIVE OR  IMMUNOLOGICAL FUNCTION.

             A number of human populations have been exposed to EDCs at high to moderate
             dosage levels of EDCs (e.g., PCBs, PCDFs, DES) during development.  These
             populations should be  thoroughly studied for latent adverse effects to determine if
             observations from rodent studies (e.g., low sperm counts, infertility in male and
             female offspring, shortened reproductive life span, ovarian atrophy, increases in
             prostatitis, etc.) with  these chemicals are manifest in  humans after in utero
             exposure.  Thus, the  DES sons should  be reexamined for declines in sperm
             numbers and semen quality and increases in benign prostatic  hyperplasia and
             prostate cancer, and the DES daughters should be followed for increased incidence
             of reproductive abnormalities and cancers as they age.  Similarly, populations
             exposed to high levels
             of p,p'-DDE in areas of the world where it is still in use should be examined for
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                                                  ORD Research Plan for Endocrine Disrupters

             increased incidences of cryptorchidism, testicular cancer, and urogenital
             malformations, as these are induced by in utero exposure to antiandrogens
             in rodents, primates, and humans. Such studies should make every effort
             to link effects with exposure or exposure-related parameters. Consideration
             should also be given to additional studies on potent, high-volume EDCs
             other than those discussed above.

             High Priority (Adjusted Score from Appendix Vl=19), Human and Exposure Focus
LNK2.4      EPIDEMIOLOGICAL  STUDIES  OF HUMAN  POPULATIONS EXPOSED AS
             ADULTS.

             Cohort-based approaches searching for adverse health outcomes in EDC-exposed
             populations  and case-control  approaches on specific  health effects  (such as
             reductions in sperm counts or increased incidences of infertility, hypospadias,
             endometriosis, or cancers of the breast and reproductive tract) are needed to
             ascertain the range of possible risks resulting from EDC exposures. For example,
             a number of  human  populations  (albeit  mostly male),  have  been  exposed
             occupationally to EDCs (e.g., DDT, ODD, DDE, TCDD, DBCP, PCBs) at moderate
             to high  dosage levels as adults.  These populations should be studied for latent
             adverse effects.  Although adults  are  not typically the most sensitive  human
             subpopulation  for the effects of EDCs, these data can be compared to high dose
             data obtained  in adult male rodent studies to determine if humans and rodents
             respond in a similar manner. Although obtaining accurate and relevant exposure
             information is likely to be difficult, case-control studies of suspected EDC induced
             diseases will be useful in the overall evaluation of the hypothesis that such effects
             are related to specific exposures.

             High/Medium Priority (Adjusted Score from Appendix Vl=25), Human and Exposure
             Focus
LNK.2.5      STUDIES  OF   WILDLIFE   POPULATIONS  TO  ESTABLISH
             RELATIONSHIPS BETWEEN EDCs AND IMMUNE FUNCTION.

             Numerous reports of immune alterations  have been reported in EDC-exposed
             wildlife  populations.  These  observations need  to  be replicated  in additional
             populations. Results should be compared  to outputs of EFF.3.2.

             Medium to Low Priority (Adjusted Score from  Appendix Vl=41);  Ecological and
             Exposure Focus
LINKAGE ISSUE 3.   ESTABLISH STATUS  AND TRENDS OF HUMAN AND  WILDLIFE
ENDOCRINE DISRUPTION AND EDC EXPOSURE

To establish the scope of potential EDC-mediated effects, there is a need to collect exposure and
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                                                 ORD Research Plan for Endocrine Disrupters

effects data systematically from different ecosystems.  It is clear that existing or proposed
resources would not allow development of major new monitoring program for EDCs.  However,
coordination with existing programs with respect to the type of data collected as well as evaluation
of existing data could prove extremely valuable. Determination of exposure levels responsible for
population level effects is an important component of the research needs.
LNK.3.1      EXAMINE EXISTING HUMAN TISSUE/SERUM BANKS FOR CORRELATIONS OF
            EDCs AND HORMONE LEVELS. IDENTIFICATION OF EDCS THAT OCCUR AT
            HIGH LEVELS IN ECOSYSTEMS.

            Human tissue and serum banks could be examined for concentrations of specific
            endocrine disrupting chemicals. Forthe contaminant information to be useful, some
            knowledge about the pharmacokinetics and metabolism would be required, as it
            would be possible to lead to false-negative conclusions if the dynamic relationship
            between exposure and biological effect mediated via hormonal alterations is not
            understood.  With respect to measurement of hormone levels, the stability of the
            hormone in serum and the age, sex, and health of the  donor would need to be
            considered in interpretation of any results.

            Medium to low priority (Adjusted Score from Appendix Vl=53); Human Focus
LNK.3.2     EXAMINE EXISTING  CANCER  AND  BIRTH  DEFECT  REGISTRIES FOR
            INCIDENCES OF EDC-LIKE HEALTH EFFECTS IN HUMANS.

            It has been suggested that the effects of EDC chemicals manifest themselves in the
            human population in a predictable fashion as a direct consequence of the role of
            hormones in reproductive development and in the regulation of some tumor types.
            The existing human health information is quite weak, and it is difficult to determine
            if effects are increasing as some have claimed. Studies are  needed  to evaluate
            whether these outcomes (e.g., hypospadias, cryptorchidism, diminished  semen
            quality, endometriosis, breast, testicular, and prostatic cancers) are increasing or
            decreasing overtime and to identify the true incidence of these  effects in the human
            population at the present time.

            Medium Priority (Adjusted Score from Appendix Vl=34), Human Focus
LINKAGE ISSUE  4: DEVELOP RISK  MANAGEMENT APPROACHES TO REDUCE OR
ELIMINATE ENVIRONMENTAL EXPOSURES TO EDCs.
LNK.4.1      CHARACTERIZATION OF THE SOURCES OF EDCs IN THE ENVIRONMENT

            To develop effective risk management strategies for EDCs, the major sources of
            EDCs entering the environment causing exposure of humans and the ecosystems
            must be identified. Such a survey could be conducted by collecting existing data
            from databases associated with the Toxic Release Inventory, hazardous waste
            sites,
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                                                  ORD Research Plan for Endocrine Disrupters

             pesticide production and use, incinerator effluent compositions,  etc.

             Medium priority (Adjusted Score from Appendix Vl=31), Risk management focus


LNK.4.2      DEVELOPMENT OF TOOLS FOR RISK MANAGEMENT OF EDCs

             Based on the exposure studies and results from  LNK.3.4, tools to manage the
             unreasonable risks associated with EDCs will be needed. These tools may include
             methods to induce  biodegradation of EDCs at  hazardous waste sites  or  in
             contaminated sediments, or pollution prevention strategies for chemical plants that
             employ or produce EDCs. These tools must significantly lower unreasonable risks
             associated with EDCs at an affordable cost.

             Medium priority (Adjusted Score from Appendix Vl=27), Risk management focus
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                                                    ORD Research Plan for Endocrine Disrupters

V. RESEARCH IMPLEMENTATION GUIDANCE

    In accordance with the uncertainties associated with the endocrine-disruption hypothesis, the
research topics identified in  this plan are quite broad  in scope and are likely to exceed  the
available resources. Implementation of this plan will therefore require extensive coordination and
communication among the research managers in ORD,  assistance from external review panels,
and continued involvement of the ORD ED Research Planning Committee, to ensure that the most
relevant and defensible research projects are selected for funding.  Targeting the research effort
is complicated by the fact that there is a considerable  existing intramural research  program in
addition to enhanced availability of extramural resources.  Coordination within the intramural
program is especially important for the Linkage Studies. These combined field and laboratory and
effect and exposure projects will require close collaboration among nearly every component of
ORD.

    It is presumed that investigator-initiated responses to Request for Applications (RFAs) derived
from this research plan will provide the basis upon which the expanded ORD research effort in
endocrine disruption will be built.  From these submissions, projects will be selected for funding
on the basis of both scientific excellence and programmatic relevancy using criteria provided below.
A similar,  parallel process will be used  to target the RFAs in the STAR (Science To Achieve
Results) Program and to select grants for funding.  Recognizing that integration of the intramural
research program with the extramural grants is crucial to effective resource utilization, intramural
and extramural RFAs will have to be targeted to achieve both the breadth and depth of balance
needed to address the  problems.  For example, when designing  the  RFA for the  intramural
research program, consideration should be given to questions such as: (1) Do we have laboratories
capable of undertaking the research? (2) Do we have scientists currently working in these areas?
(3) What is scope of the effort needed to study the problem? and (4) Does the  intramural program
have the capacity to accomplish goals in a timely manner? Answers to such questions will provide
an important element in determining how best to focus the intramural and the extramural RFAs.
While the particular processes vary, ORD maintains a high standard of external peer review
regardless of whether  the intramural or extramural pathway  is taken to  resolve  a scientific
uncertainty. Intramural project proposals are  subject to external scientific review and internal
relevancy review at the initiation stage, as well as periodic programmatic reviews, and during the
tri-annual  site reviews of individual research divisions by external scientific panels.  Extramural
project proposals are subject to both study  section review by external experts, and relevancy
reviews by Agency staff prior to funding.

    The scope of the endocrine disrupter problem suggests that additional oversight  of the ORD
effort may be required to maintain an appropriate balance among the various components of the
research plan and to ensure that the major data gaps are addressed.  The danger in a program
developed largely through investigator-initiated activities, even within  a defined topic such as
endocrine disruption, is that the individual components do not complement each other sufficiently
to achieve the overall goals as stated in the Introduction. To help avoid this potential problem,
ORD's Laboratories and Centers are expected to develop individual  implementation plans for
addressing the research activities identified in this plan. These implementation plans should be
reviewed by the ORD Research Planning Committee  for their ability  to provide  a  useful and
integrated research output to the Program Offices.  Annual reports of progress and presentation
of the upcoming research objectives from each  Laboratory and Center will facilitate the exchange
of information within ORD, assist in the direction of work to the highest priority areas, help fine-tune
the research directions as new information from the program emerges, and communicate with
EPA's Program Offices on progress in understanding the nature and extent of the EDC problem.
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                                                    ORD Research Plan for Endocrine Disrupters

Interactions between the recipients of the STAR grants and the intramural investigators involved
in endocrine disrupter research through annual or bi-annual workshops are also encouraged.

    The following decision-making  criteria for  use  in setting  priorities within  the  endocrine
disrupters research program have been developed:
    Risk-Based Planning:
    Scientific Excellence:
    Programmatic Relevance:
    Other Sources of Data:
    Capabilities and Capacities:
    Sequence of Research:
Research that addresses an element of the risk assessment
paradigm  and  is  designed  to  reduce  the  greatest
uncertainties is of the highest priority.

The quality of the science selected for support is of critical
importance to both the regulatory application of the resulting
information and the overall credibility of the Agency.

The degree to which a research project addresses a specific
statutory requirement will be an important ranking factor.

It is important to determine whether research that will provide
equivalent or complementary  information is underway or
planned elsewhere.  A high priority will be given to projects
that leverage resources within or outside the Agency.

The likelihood that research can be implemented within a
reasonable period of time using existing facilities, expertise,
and available  resources will be considered when ranking
competing projects.  This criterion applies to work conducted
intramurally as well as in situations where in-house expertise
is  needed to oversee the completion of work conducted
through a cooperative agreement, contract or grant.

The value of some research, regardless of its priority ranking
on other criteria, is dependent upon the completion of other
work.   Research that is dependent upon  completion of
otherwise equally ranked work will  receive a lower priority.
Such  time  dependency requires  that  periodic  review of
progress is made in  order to move to the next stage.
    As noted in the Introduction, an important component of the implementation of this plan will
be an in-depth review in three to four years to ensure that it remains appropriately focused and to
re-adjust priorities as needed. For example, research related to risk management was given only
a "medium" priority in this plan pending resolution of the extent the endocrine disruption problem.
Such efforts are likely to grow in importance and merit a higher priority for funding.  Conversely,
other topics may fade in  importance as the key uncertainties are addressed.
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VI. REFERENCES

Ankley, G.T.,  R.D. Johnson, G. Toth, L.C. Folmar, N.E. Detenbeck, and S.P. Bradbury (1997).
Development of a Research Strategy for Assessing the Ecological Risk of Endocrine Disrupters.
Reviews in Toxicology 1:71-106.

Ankley et al. (30 coauthors).  1998.  Overview of a workshop on screening methods for detecting
(anti-) estrogenic/androgenic chemicals in wildlife. Environ. Toxicol. Chem. 17:68-87.

CENR (1996). The Health and Ecological Effects of Endocrine Disrupting Chemicals: A Framework
for  Planning.  Committee on  Environment and Natural  Resources,  National Science  and
Technology Council, Office of Science and Technology Policy. November 22,1996, Washington
DC.

CRS Report for Congress.  Summaries of Environmental Laws Administered by the Environmental
Protection Agency.   M.R. Lee, Coordinator.  Congressional Research Service.  The Library of
Congress. January 3, 1995.

Gray, L.E. Jr., W.R. Kelce, T. Wiese, R. Tyl, K. Gaido, J. Cook, G. Klinefelter, D. Deaulniers, E.
Wilson, T. Zacharewski, C. Waller, P. Faoster, J. Laskey, J. Reel, J. Geisy, S. Laws, J. McLachlan,
W. Breslin, R. Cooper, R. DiGuilio, R. Johnson, R. Purdy, E. Mihaich, S. Safe, C. Sonneschein, W.
Welshons, R. Miller, S. McMaster and T. Colborn (1997). Endocrine Screening Methods Workshop
Report: Detection of Estrogenic and Androgenic Hormonal and Antihormonal Activity for Chemicals
that Act Via Receptor or Steroidogenic Enzyme Mechanisms. Reproductive Toxicology 11 (5):719-
750.

Kavlock, R.J.,  G.P. Daston,  C. DeRosa, P. Fenner-Crisp, L.E. Gray, S. Kaattari, G. Lucier, M.
Luster, M.J. Mac, C. Maczka,  R. Miller, J. Moore, R. Rolland, G. Scott, D.M. Sheehan, T. Sinks, and
H.A. Tilson (1996). Research Needs for the Risk Assessment of Health and Environmental Effects
of Endocrine Disrupters: A Report of the U.S. EPA Sponsored Workshop. Environmental Health
Perspectives 104 (Supplement 4): 715-740.

Reiter, L.W.,  C. DeRosa, R.J. Kavlock, G. Lucier, M.J. Mac, J. Melillo, R.L Melnick, T. Sinks and
B. Walton (1998).  The U.S.  Federal Framework for Research on Endocrine Disrupters and an
Analysis of Research Programs Supported during  Fiscal Year 1996.   Environmental Health
Perspectives. 106(2).

USEPA (1996a).  Strategic Plan for the Office of Research and Development. Washington, DC,
EPA/600R-96/059, 60 pp.

USEPA  (1996b).   Environmental  Endocrine Disruption:  Effects  Assessment and  Analysis
Document. Risk Assessment Forum, December, 1996. Washington,  DC.
                                         32

-------
                                             ORD Research Plan for Endocrine Disrupters
APPENDIX I.  Time Lines for Major Research Questions.
OVERARCHING QUESTION
What effects are occurring in
exposed humans and wildlife
populations?

What are the chemical classes of
interest and their potencies?

What are the dose-response
characteristics in the low-dose
region?

Do our current testing guidelines
adequately evaluate potential
endocrine mediated effect?

What are the effects of exposure
to multiple EDCs, and will a TEF
approach be applicable?

How, and to what degree, are
humans and wildlife exposed to
EDCs?

What are the major sources and
environmental fates of EDCs?

How can unreasonable risks be
managed?	
                                    96
97
98
FISCAL YEAR

     99
00
01
02
                                                   33

-------
                                                    ORD Research Plan for Endocrine Disrupters

APPENDIX II.  SUMMARY DELIBERATIONS OF THE EPA WORKSHOPS

       The premise of these workshops was given that environmental  endocrine disrupting
chemicals (EDCs) have caused a variety of adverse biological effects in wildlife species, domestic
animals, and humans, there is a need to identify research that would assist the federal government
in making informed public health and regulatory decisions. An "environmental endocrine disrupter"
was broadly defined as "an exogenous agent that interferes with the production, release, transport,
metabolism, binding, action, or elimination of natural hormones in the body  responsible for the
maintenance of homeostasis and the regulation of developmental processes."  Importantly, this
definition reflects a  growing awareness that the issue extends considerably beyond that  of
"environmental estrogens" and includes anti-androgens and agents that act on other components
of the endocrine system such as the thyroid and pituitary glands.

       The majority of the invited experts at the Raleigh workshop agreed  that the endocrine
disrupter hypothesis was of sufficient concern to warrant a concerted research  effort. In particular,
the study of potential effects on reproductive development at multiple phylogenetic levels was
deemed the most important area in need of attention.  It was emphasized repeatedly that the
developing embryo, fetus, and  neonate should  not be viewed as small adults and that the
processes of development are especially vulnerable to brief periods of endocrine disruption.
However, for many of the effects reported in both wildlife and humans that have been attributed
to, or associated with, endocrine disruption, exposure assessment generally has been inadequate
for quantitative risk assessment.  Because of this, some participants felt it was difficult to critically
evaluate and establish the level of priority relative to other research topics. Still other participants
reminded the workshop not to lose sight of the presence of natural occurring endocrine disrupters
(e.g., phytoestrogens) as the effects of man-made chemicals are studied.

       The objectives of the ecological research strategy workshop were two-fold: to identify
research  needs and approaches to determine the relative ecological risk of EDCs compared  to
other  stressors on populations and communities,  both from a prospective and retrospective
standpoint, and to make recommendations for developing or modifying the requirements for testing
and evaluating chemicals and environmental samples so as to ensure that those exerting toxicity
through specific endocrine axes will be characterized adequately.

       Several general comments pertaining to future research on endocrine disrupting chemicals
emanated from the discussions.  These include the recognition that there was a great advantage
in bringing together a multi-disciplinary group of scientists representing both the human health and
ecological health viewpoints to help identify common issues and that this interaction  must be
nurtured  as the research agenda  unfolds.  The workgroup noted some key similarities and
differences exist between endocrine disrupters and other chemicals which can cause adverse
biological effects.  Two of the key differences are:  the presence of natural ligands within the body
that must interact at some level with the exogenous chemical; and that the  concentrations of the
natural ligands within the body fluctuate during the life cycle and must be maintained within narrow
limits at key times during development. This latter point makes consideration of timing of exposure
a very significant factor in any assessment. While timing of exposure is important, many EDCs are
persistent in the environment and bioaccumulate, and exposures are widespread throughout the
entire globe.  This can have important ramifications on a biological system that is geared to often
cyclical homeostatic control mechanisms such as many of the hormones of the endocrine system.
Lastly, the mechanistic basis of the interaction with biological systems presages the induction  of
subtle effects at low doses that must be interpreted as adverse or not. As the level of organization
at which  biological  responses to  endocrine  disrupters  are observed decreases (e.g.  from
physiological to cellular to molecular), the challenge to describe the effects as adverse at the level
                                          34

-------
                                                     ORD Research Plan for Endocrine Disrupters

of the individual and the population increases.  In this regard, endocrine disrupters are not unlike
other types of chemicals for which toxicological information is amassed.

       In general,  it was felt that linking  specific exposures to specific effects in the general
environment would often be difficult due to the complexities of exposure, the latency of the effects,
and the at times subtle nature of the outcomes.  Therefore, to confirm the validity of the hypothesis
it is likely that there will be heavy reliance on the application of epidemiological criteria for causality
(strength of the association,  presence  of a dose-response relationship, specificity of the
association, consistency across studies, biological plausibility, and coherence of the  evidence).
Such considerations will have significant impact on the types of research activities necessary to
adequately confirm or refute the central hypothesis. Ten broad categories of research needs were
identified: basic research, biomarkers, database development, exposure determination, exposure
follow-up, mixtures, multi-disciplinary studies, risk assessment methods, hazard identification, and
sentinel species.   Several workgroups noted  the complexity in  identifying whether effects of
xenobiotics on  those systems  were the result of primary or secondary  aspects of endocrine
disruption.  Workshop participants particularly noted that identification and characterization of
effects on the developing  reproductive system were considered  of high priority for additional
research due to the high sensitivity and  frequent irreversibility of effects following  even brief
exposures. More refined exposure assessments and research on the toxicology of mixtures were
also  considered to  be of high importance.  Special emphasis was placed on consideration of the
unique challenges endocrine disrupters might pose to the risk assessment paradigm. Interestingly,
the fact that there is an understanding of the mechanisms underlying endocrine disruption induced
by some chemicals was seen as an advantage in that it may result in a common, biologically based,
human health risk assessment process for all effects (cancer and noncancer).

       The following specific research strategies were suggested over the course of the Duluth
workshop to start to address the research  recommendations listed  above:

       1)  Review and compile available data on endocrine function and endocrine cycles in
             species of concern (e.g., vulnerable species) to identify areas where additional
             research is needed.

       2) Consolidate and review data from ongoing monitoring programs (e.g., Environmental
             Monitoring and Assessment Program, National WaterQuality Assessment Program,
             National Status and Trends  Program) to identify trends that may be associated with
             effects of EDCs.

       3) Modify existing monitoring programs to include information  relevant to EDCs such as
             measurement of relevant chemicals, information about sex ratios and endocrine
             parameters.

       4) Increase emphasis on research in comparative endocrinology and toxicology to allow
             extrapolation among species.

       5)  Conduct focused research projects at a  few selected  sites with known endocrine
             disrupter problems. Examine multiple species at several levels of organization to
             establish  linkages  between  endpoints  measured in the  laboratory  at  the
             suborganismal/individual  level  and changes in  the  field at  higher  levels of
             organization. Strategies and information developed from these projects could then
             be used to assess or predict impacts of EDCs in other areas.
                                          35

-------
                      Appendix III. Overview of Research Plan, Tasks, and Outputs for Endocrine Disruptors
Subtopic
Strategic Focus
Tasks
Products
Uses
Biological        Defining the classes of
Effects           chemicals that act as EDCs
                 and their potencies
                 Evaluating current testing
                 guidelines and monitoring
                 procedures for adequacy of
                 assessment of EDCs
                 Determining the shapes of
                 dose-response curves for
                 EDCs at relevant exposures
                 and the tissue levels
                 associated with adverse effects
                 Describing the normal
                 endocrine profiles in wildlife
                 species
                 Extrapolating effects at the
                 individual level to populations
                 for fish and wildlife
                               Develop in vitro and in vivo methods and
                               structure-activity models to screen for
                               EDC action
                               Enhance ability of existing test methods
                               (e.g., multi-generational studies in
                               mammals and life cycle tests in fish and
                               wildlife) to evaluate manifestations of
                               endocrine disruption and underlying
                               modes of action

                               Assess effects of EDC exposure on
                               neuroendocrine, immunological, and
                               reproductive function in developing and
                               adult animals in support of
                               pharmacokinetic and biologically based
                               dose-response models, with emphasis on
                               animal models of EDC-induced human
                               diseases

                               Provide baseline  endocrine information for
                               wildlife populations and their laboratory
                               surrogates, with emphasis on comparative
                               endocrinology and developmental control
                               of sex differentiation, especially for
                               species with little  historical attention

                               Translate results from measurement
                               endpoints at lower levels of biological
                               organization to impacts on populations
                               and communities  through use of
                               microcosms and mesocosms

                               Identify appropriate sentinel species for
                               environmental monitoring
                                         Methods to describe the hazard
                                         potential of EDCs and likely
                                         modes of action and potencies
                                         Revised testing guidelines that
                                         are more indicative of the most
                                         sensitive life-stage, sex, and
                                         target tissue for chemicals that
                                         act through the endocrine system


                                         Animal  models of EDC-induced
                                         health effects that provide
                                         increased understanding of the
                                         types and magnitudes of risks for
                                         exposure to EDCs during various
                                         phases  of the life cycles
                                         Databases of endocrine profiles
                                         in species from multiple
                                         phylogenetic levels and improved
                                         understanding of the role of the
                                         endocrine system in sex
                                         differentiation

                                         Models predicting population
                                         level effects from studies at lower
                                         levels of biological organization
                                Hazard
                                characterization to
                                support implementation
                                of the FQPAand the
                                SDWA

                                To improve  regulatory
                                testing requirements
                                and data interpretation
                                To provide quantitative
                                dose-response
                                evaluation and reduced
                                uncertainties for
                                human health
                                extrapolations
                                To assess the impact
                                of EDCs in wildlife
                                populations
                                To facilitate ecological
                                risk assessment based
                                on effects in
                                individuals
                                                                       36

-------
                     Appendix III. Overview of Research Plan, Tasks, and Outputs for Endocrine Disruptors
Subtopic
Strategic Focus
Tasks
Products
                Uses
                 Characterizing the effects of
                 exposure to multiple EDCs
                              Systematically study the interactions of
                              EDCs at low, relevant dose levels to
                              understand potential for synergism
                                        Assessment of the validity of the
                                        additivity principal for EDCs and
                                        predictive models for synergistic
                                        interactions
                                To reduce uncertainties
                                associated with
                                assessment of
                                exposure to multiple
                                EDCs
Exposure
Studies
Developing a framework to
characterize and to diagnose
and predict ecological and
human exposure to EDCs
                 Providing adequate tools to
                 estimate exposure to EDCs
                 Determining total ecosystem
                 and human exposures to EDCs
                 of concern
Use physicochemical attributes to identify
transport, transformation, and
environmental fate characteristics
associated with exposure scenarios of
concern to biological organisms

Construct compartmental models to
predict environmental behaviors

Develop new methods, and refine existing
ones (e.g., analytical chemistry, sample
extraction, biomarkers) to acquire data for
compartmental models, with emphasis on
the transport and transformation in
sediments and tools for assessing
exposure in individuals

Examine multi generational transfer of
EDCs in ecosystems, including
biomagnification processes important to
higher vertebrates

Provide information on EDC exposure
distribution in the general human
population	
Validated models to predict and
assess transport, fate and
exposure to EDCs from source to
receptor
                                                                      Field and laboratory tools to
                                                                      better quantitate EDCs in multi-
                                                                      media
To conduct preliminary
environmental
exposure assessments
and set  priorities for
additional focused
research
                                To improve
                                characterization of
                                exposure to EDCs
                                                                      Exposure assessments for EDCs
                                                                      in key wildlife species and the
                                                                      general human population
                                To monitor the
                                environment for signals
                                of EDC exposure and
                                effects
Linkage of
Effects,
Exposure and
Risk
Management
Integrating human and
ecological effects research with
exposure research within the
risk assessment paradigm
Construct framework to identify,
characterize, prioritize and assess
potential and risks to EDCs and provide
database for preliminary risk
characterization
Coordinated process for
identifying exposure and effects
of concern for additional
intensive characterization of risk
To conduct preliminary
risk assessments and
assist research
prioritization
                                                                      37

-------
                     Appendix III. Overview of Research Plan, Tasks, and Outputs for Endocrine Disrupters
Subtopic
Strategic Focus
Tasks
Products
Uses
                 Determining classes and
                 concentrations of EDCs
                 associated with observations of
                 endocrine disruption
                 Establishing status and trends
                 of human and wildlife
                 endocrine disruption and EDC
                 exposure


                 Developing risk management
                 approaches to reduce or
                 eliminate environmental
                 exposure to EDCs
                              Develop informational database for EDCs,
                              including biological effects, environmental
                              concentrations, and historical trends from
                              existing monitoring programs

                              Conduct integrated toxicology and
                              exposure studies in areas or human
                              populations with suspected contamination
                              or exposure to EDCs

                              Examine existing monitoring efforts and
                              exposure and effect registries for
                              relevancy to addressing EDC uncertainties
                              Identify major sources of EDCs entering
                              the environment

                              Develop tools for risk management such
                              as biodegradation processes or pollution
                              prevention strategies
                                       Database on EDC levels in the
                                       human environment and various
                                       ecosystems associated with
                                       biological effects of concern
                               Centralized Information
                               source for
                               environmental
                               monitoring of EDCs
                                       Consolidated databases of status
                                       and trends relevant to EDC
                                       exposures and effects
                                       Risk management tools for
                                       elimination or prevention  of
                                       exposures to significant EDCs
                               For environmental
                               monitoring and
                               comparison of effects
                               with more intensive
                               exposures

                               To develop remedial
                               actions where adverse
                               effects of EDCs have
                               been documented
       EDC = Endocrine Disrupting Chemical
       FQPA = Food Quality Protection Act
       SDWA = Safe Drinking Water Act
                                                                   38

-------
APPENDIX IV. Cross Tabulation of the Nine Overarching Research Questions with the Individual Research Activities Specified in the
Research Plan
























ISSUE
EFF1
EFF2

EFF3





EFF4



Determine the classes of chemicals that act as EDCs and their potencies
Evaluate current testing and monitoring procedures for adequacy of assessment of the
effects of EDCs
Mode of action studies in laboratory animal models following developmental exposure.
Developmental and acute effects on immune function
Studies of EDC-induced human effects in animal models
Pharmacokinetic studies of highly relevant EDCs
Development of BBDR models for highly relevant EDCs
Mode of action studies in pubertal and adult laboratory models
Definition of baseline endocrine status in wildlife populations
Studies in comparative endocrinology and toxicology
Studies on the role of hormones in sexual differentiation




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APPENDIX IV. Cross Tabulation of the Nine Overarching Research Questions with the Individual Research Activities Specified in the
Research Plan





















EFF5


EFF6
EXP1

EXP2


EXP3


LNK1
Bioassays for evaluating integrated effects
Evaluation of effects at populations and community levels
Determination of sentinel species
Studies of interactions of low, relevant dose levels of mixtures
Identification and evaluation of classes of suspect EDCs
Development and application of compartmental models
Abiotic Fate
Biotic Fate
Develop measurement methods and biomarkers for high throughput
Study inter-generational transfer in ecosystems
Study bioaccumulation in food webs
Obtain population based distributions of EDC exposures
Framework for comprehensive, multi-laboratory EDC investigations




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40

-------
APPENDIX IV. Cross Tabulation of the Nine Overarching Research Questions with the Individual Research Activities Specified in the
Research Plan





















LNK2
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Evaluation of existing data and programs for EDC monitoring
Integrated studies of wildlife at contaminated sites
Examine human populations exposed developmentally
Examine human populations exposed as adults
Studies of wildlife populations to establish relationships between EDCs and immune
function
Examine existing human tissue banks for correlations between EDCs and hormone
levels
Examine existing cancer and birth defect registries for incidences of EDC like effects
Characterization of the sources of EDCs in the environment
Development of risk management tools for EDCs





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41

-------
APPENDIX V.a. TASK SUMMARY AND PROPOSED SEQUENCE FOR EFFECT STUDIES

ISSUE
EFF.1.1
EFF.2.1
EFF.3.1
EFF.3.2
EFF.3.3
EFF.3.4
EFF.3.5
EFF.3.6
EFF.4.1
EFF.4.2
EFF.4.3
EFF.5.1
EFF.5.2
EFF.5.3
EFF.6.1
FOCUS1
HH
X
X
X
X
X
X
X
X






X
EE
X
X
X
X




X
X
X
X
X
X
X
EX















PRIORITY2

H(1)
H(13)
H(23)
H/M(27)
H(10)
H(24)
H/M(34)
M(37)
H(26)
M(33)
H(36)
H(26)
H/M(22)
H(26)
H(16)
PROPOSED TIME FRAME3
FY96
X
X
X


X


X


X



FY97
X
X
X

X
X


X
X
X
X

X
X
FY98
X
X
X

X
X
X
X
X
X
X
X
X
X
X
FY99
X
X
X
X
X
X
X
X

X
X

X
X
X
FYOO


X
X
X

X
X




X


FY01



X


X








   1 HH, Human Health, EE, Ecological Effect, EX, Exposure Assessment
   2 As Priority (Priority Score). Priorities H (High), M Medium, (L) Low. See Appendix VI for basis of
   prioritization score.
   3 Assignment based on logical sequence of research, placing issues addressing the uncertainties of
   most concern earlier in the implementation process.
                                          42

-------
APPENDIX V.b. TASK SUMMARY AND PROPOSED SEQUENCE FOR EXPOSURE STUDIES

ISSUE
EXP.1.1
EXP.1.2
EXP.2.1
EXP.2.2
EXP.2.3
EXP.3.1
EXP.3.2
EXP.3.3
FOCUS1
HH




X
X

X
EE


X

X
X
X
X
EX
X
X
X
X
X
X
X

PRIORITY2

H(9)
H(28)
H(28)
H(10)
H(21)
M(35)
M(34)
H(22)
PROPOSED TIME FRAME3
FY96
X
X


X



FY97
X
X
X

X
X
X
X
FY98

X
X
X
X
X
X
X
FY99

X
X
X
X
X
X
X
FYOO


X
X
X
X
X
X
FY01







X
1 HH, Human Health, EE, Ecological Effect, EX, Exposure Assessment
2 As Priority (Priority Score). Priorities H (High), M Medium, (L) Low. See Appendix VI. for basis of
prioritization score.
3 Assignment based on logical sequence of research, placing issues addressing the uncertainties of most
concern earlier in the implementation process.
                                           43

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APPENDIX V.c.  TASK SUMMARY AND PROPOSED SEQUENCE FOR LINKAGE STUDIES

ISSUE
LNK.1.1
LNK.2.1
LNK.2.2
LNK.2.3
LNK.2.4
LNK.2.5
LNK.3.1
LNK.3.2
LNK.4.1
LNK.4.2
FOCUS1
HH
X


X
X

X
X


EE
X
X
X


X




EX
X
X
X
X
X
X
X



PRIORITY2

H(24)
H(29)
H(14)
H(19)
H/M(25)
M/L(41)
M/L(53)
M/L(34)
M(31)
M(27)
PROPOSED TIME FRAME3
FY96
X
X








FY97
X
X
X
X
X



X

FY98
X
X
X
X
X

X
X
X

FY99
X

X
X
X
X
X
X
X
X
FYOO


X
X
X
X
X
X

X
FY01



X
X
X
X


X
1 HH, Human Health, EE, Ecological Effect, EX, Exposure Assessment
2 As Priority (Priority Score).  Priorities H (High), M Medium, (L) Low. See Appendix VI for basis of
prioritization score.
3 Assignment based on logical sequence of research, placing issues addressing the uncertainties of most
concern earlier in the implementation process.
                                           44

-------
APPENDIX VI. Cumulative Priority Ranking Scores1
Issue
EFF1.1
EFF2.1
EFF3.1
EFF3.2
EFF3.3
EFF3.4
EFF3.5
EFF3.6
EFF4.1
EFF4.2
EFF4.3
EFF5.1
EFF5.2
EFF5.3
EFF6.1
EXP1.1
EXP1 .2
EXP2.1
EXP2.2
EXP2.3
EXP3.1
EXP3.2
EXP3.3
LNK1.1
LNK2.1
LNK2.2
Short Title
Chemical Classes
Testing Procedures
Modes of Action
Developmental Immune Effects
Animal Models of Diseases
Pharmacokinetics
BBDR Models
Adult neuroendocrine Effects
Endocrine Baselines
Comparative Endocrinology
Sexual Differentiation
Integrated Bioassays
Population Effects
Sentinel Species
Interactions
Classes of EDCs
Compartmental Models
Abiotic Fate
Biotic Fate
High Throughput
Intergeneratioanl Transfer
Trophic Dynamics
Population Distributions
Comprehensive Framework
Existing Monitoring
Integrated Wildlife Studies
Programmatic
Relevance
8
8
16
15
9
11
16
19
18
15
20
14
9
15
9
8
15
16
8
13
18
17
9
21
13
14
Biological
Concern
8
14
14
17
8
15
15
20
14
15
13
15
9
11
12
13
15
22
9
15
12
13
15
9
14
8
Potential
Impact
8
14
9
15
9
14
9
15
13
15
13
8
9
15
9
8
13
8
15
9
13
14
8
11
19
8
Sequence
8
9
9
10
8
14
13
11
8
14
15
14
15
10
16
10
15
11
9
9
17
16
15
9
9
9
Technical
Success
10
9
16
11
17
11
22
13
14
15
16
16
21
16
11
11
11
12
10
16
16
15
16
15
15
16
Total Score
42
54
64
68
51
65
75
78
67
74
77
67
63
67
57
50
69
69
51
62
76
75
63
65
70
55
Adjusted Score
1
13
23
27
10
24
34
37
26
33
36
26
22
26
16
9
28
28
10
21
35
34
22
24
29
14
45

-------
APPENDIX VI. Cumulative Priority Ranking Scores1
LNK2.3
Issue
LNK2.4
LNK2.5
LNK3.1
LNK3.2
LNK4.1
LNK4.2
Human Development
Short Title
Human Adults
Wildlife Immunotoxicology
Tissue Banks
Registries
Sources of EDCs
Management of EDCs
14
Programmatic
Relevance
14
16
18
17
8
9
9
Biological
Concern
15
15
22
10
16
10
8
Potential
Impact
8
15
15
10
9
9
9
Sequence
10
15
16
15
22
24
20
Technical
Success
19
21
23
23
17
16
60
Total Score
66
82
94
75
72
68
19
Adjusted Score
25
41
53
34
31
27
 1 Each member of the planning committee assigned a weight of 1 to 3 (1 being the highest) to each of five factors (Programmatic Relevance, Magnitude of
Biological Concern, Potential Impact of Research, Sequence of the Research, and Technical Feasibility of the Research). The values in the columns under each
of the five factors is the sum of the weights assigned by 8 individuals (thus, an issue would receive a highest possible score of 8, and the lowest a possible score
of 24).  The column marked "Total Score" is the sum of weights for the five individual factors, while the Adjusted Score substracts the lowest total score, and
then adds one, such that the highest priority issue has a value of 1. This is the value used in the text and in Appendix Va-c.
                                                                       46

-------
APPENDIX VII. Endocrine Disruptor Research Plan Arrayed Against the Government Performance and  Results Act Structure



















Agency Goals/Objectives/Sub-Objectives

EFFECTS






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8: PROVIDE SOUND SCIENCE TO IMPROVE UNDERSTANDING OF ENVIRONMENTAL RISK AND DEVELOP AND IMPLEMENT INNOVATIVE APPROACHES
FOR CURRENT AND FUTURE ENVIRONMENTAL PROBLEMS
ORD Science Objective #3: Emerging Risk Issues: Establish
capability and mechanisms within EPA to anticipate and identify
environmental or other changes that may portend future risk,
integrate futures planning into ongoing programs, and promote
coordinated preparation for and response to change
ORD Science Sub-Objective #3.2: Endocrine Disrupters


























MM-35
LNK.
2 2
3.1
MM-56
LNK.
2.1





















MM-64
EFF.
1.1
2.1
MM-65
EFF.
5.1





















MM-7
EFF.
5.1
5.3
LNK.
2.2
2.3
2.4
2.5
vlM-12
EFF.
3.1
3.2
3.3
3.4
3.5
3.6
vlM-30
LNK.
1.1
VSM-56
LNK.
2.1





MM-24
EFF.
4.1
4.2
4.3
MM-58
EFF.
6.1
MM-64
EFF.
1.1
2.1
















VIM-23
EFF.
5.2
5.3



















































MM-66
EXP.
1.1
1.2
























MM- 17
EXP.
2.1
2.2
2.3
MM-45
EXP.
3.1
3.2
3.3
MM-57
LNK.
2.1















MM- 8
EFF.
5.1
5.3
LNK.
2.2
2.3
2.4
2.5
MM-28
LNK.
1.1
MM-36
LNK.
2 2
3.1







































VIM-63
LNK.
3.3
LNK.
2.3
2.4
2.5
3.2




















MM-29
LNK.
1.1 "

























MM-55
LNK.
2.1

























•1M-18
LNK.
4.1
4.2


























































































































































                                                                       47

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