xvEPA
United States
Environmental Protection Agency
Pollution Prevention and
Toxics (7407)
Winter 1999
EPA 747-N-99-001
Chemicals in Our Community
News and Information
IN THIS ISSUE:
Endocrine Disrupters
PBTs
Our Approach to
Endocrine Disrupters
Lynn R. Goldman, M.D.
Dr. Goldman served as Assistant Administrator of the Office of Prevention, Pesticides
and Toxic Substances from the Spring of 1993, and chaired the Endocrine Disruptor
Screening and Testing Advisory Committee. She left the Agency on December 31,1998.
Recently, increased scientific and public attention has focused on the potential
effects of synthetic chemicals on the hormone, or endocrine, systems of humans and
wildlife. The endocrine system consists of the glands and the hormones they produce
that help guide the development, growth, reproduction and behavior of humans and
animals. Concerns are about potential health effects, like cancers and developmental
toxicity, as well as adverse effects on species in the environment. Since we do not
know enough about the complex interactions of chemicals and hormone systems,
EPA's first efforts in dealing with the emerging issue of environmental endocrine
disrupters were in the area of research.
EPA has been a leader within the federal government in developing the science
related to endocrine disruption. EPA held two workshops in 1995 to determine what
research was needed to respond to human health and ecological questions associated
with endocrine disrupters. EPA initiated the following actions identified from the
workshops:
(1) In 1996, established a research program on endocrine disrupters that grew to $14
million per year, $8 million of which is dedicated to research in academic laboratories;
(2) Assessed the scientific literature related to endocrine disrupters and published a
report entitled, Special Report on Environmental Endocrine Disruption: An
Effects Assessment and Analysis in 1997;
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(3) Chaired an interagency committee to
develop an inventory of federal research on
endocrine disrupters; and
(4) Funded a National Research Council study
on the science of endocrine disruption.
Fourteen federal agencies participated in the
development of the inventory, which will be used
to coordinate research efforts and identify issues
that are not funded. The U.S. inventory has
become the model for an international inventory
to coordinate research among other countries.
In August 1996, the Congress concluded that
research was not enough. Concerned by the
unexplained rise in breast cancer and other
diseases that seem to be related to the endocrine
system, Congress included a requirement in the
Food Quality Protection Act (FQPA) that EPA
screen pesticides for estrogenic effects on the
female reproductive system that may contribute
to disease. Just a few days after the passage of
the FQPA, Congress passed amendments to the
Safe Drinking Water Act which contained similar
provisions to screen drinking water sources for
estrogenic endocrine disrupting chemicals. Both
bills also authorized EPA to test for other
endocrine effects.
Faced with the challenge of developing a
screening program in an area where so many
questions were still unanswered by scientific
research, and with the hope that a consensus
would speed acceptance and implementation by
industry, I thought that a consensus-based
approach, while difficult, would be the best way
to proceed. The Agency appointed an advisory
committee to assist in determining how to set
priorities for substances, what short term
screening and analytical tools the Agency should
use, and what tests could be employed to enable
the Agency to fully assess the hazard of
suspected endocrine disrupters.
We tested the breadth of support for this
approach by convening a meeting with our major
stakeholders on May 15, 1996. All stakeholders
endorsed forming an advisory committee and on
October 16, 1996, the Endocrine Disrupter
Screening and Testing Advisory Committee,
better known as ED STAC, was formed.
ED STAC was composed of 39 members
representing the pesticide and commercial
chemical industries, small businesses, state
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In
Our Approach to
Endocrine Disrupters 1
The Endocrine Disrupter Story ...3
Sorting and Priority Setting 5
Screening and Testing 7
EPA's Strategy for Priority
Persistent, Bioaccumulative,
and Toxic (PBT) Pollutants 9
Reducing PBT Chemicals
in Waste 10
How EPA is Reviewing
New PBT Chemical Substances 11
Progress of the Great Lakes
Binational Toxics Strategy 13
Update on EPA's Fish
Contamination Program 14
EPA's Draft Action Plan
for Mercury 16
Preparing the Mercury
Research Strategy 17
Chemicals in Our Community is published
by EPA's Office of Pollution Prevention &
Toxics (OPPT) to increase public awareness
of and access to news and information on
toxic chemicals and pollution prevention
available through OPPT. This resource is
also available on the Internet at: http://
www.epa.gov/opptintr/opptpub.htrn.
Mailing address:
Chemicals in Our Community
US EPA (7407)
Office of Pollution Prevention & Toxics
401 M Street, SW
Washington, DC 20460
Advisory Board:
IAB Project Manager:
Georgianne McDonald
EAD Project Manager: Mary Wigginton
Publisher: Maria Hendriksson
Senior Editors: Georgianne McDonald,
Diane Sheridan, and Mary Wigginton
OPPT Divisional Representatives:
Dan Fort (EETD), Odelia Funke (IMD),
Patricia Grim (OPME), Leonard Kiefer (RAD),
Chris Tirpak (CCD), and Chen Wen (PPD).
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The Endocrine Disrupter Story
Gary Timm
Endocrine Disrupters
The endocrine system is a chemical
communication system that coordinates and
regulates the processes that make the life of a
multicellular organism possible. An endocrine
system is essential to the life of multicellular
animals and is found in all mammals, birds, fish
and invertebrates. Hormones are produced by
various glands and travel through the blood to
receptors which are located in various tissues
throughout the body. Hormones are biologically
very potent molecules, and are therefore
effective at small concentrations (e.g., parts per
trillion). Much like a lock and key, hormones act
by binding to receptors that are produced within
cells. The hormone-receptor complex switches
on or switches off specific biological processes
in cells. The receptors are quite specific for the
appropriate hormone but they can interact with
molecules that are similar to the natural
hormone. Over 50 hormones have been
identified in humans and other vertebrates.
Examples of biological processes controlled by
hormones include sexual differentiation, growth
and function of reproductive organs (testosterone
and estradiol); control of blood sugar (insulin);
and body growth and energy production (growth
hormone and thyroid hormone).
The evidence of endocrine disruption is
substantially stronger for fish and wildlife than
for humans. A series of field and laboratory
investigations with marine snails demonstrates
that compounds like tributyltin, which are used
in antifouling paints on ships, can have
significant hormonal effects on some snail
species at concentrations 1,000 times lower than
lethal exposure concentrations. These
compounds can irreversibly induce male sex
characteristics on females (masculinization)
which can lead to sterility or reduced
reproduction. Field investigations in many parts
of the world suggest this class of compounds
may be responsible for localized reductions in
specific snail populations. Feminized males and
hermaphroditic fish (fish having reproduction
organs of both sexes) have been observed in
rivers below sewage treatment plants. Scientists
suspect that natural human estrogens, synthetic
estrogens in birth control pills, and substances
used in the manufacture of certain detergents are
involved. Researchers have documented
masculinization, altered sexual development and
decreased fertility for some fish species near
pulp and paper plant discharges. In many cases
specific causative agents have not been
identified. However, correlative data supported
by laboratory studies in many cases suggest that
compounds such as alkyl phenol ethoxylates,
their degradation products, chlorinated
dibenzodioxins and difurans, and polychlorinated
biphenyls (PCBs) could be the causative agents.
One of the most fully documented examples
of ecological effects caused by disruption of
endocrine function was reported for alligators in
Lake Apopka, Florida. Detailed field and
laboratory investigations revealed that a mixture
of pesticides (dicolfol, DDT, and its breakdown
product, DDE) associated with a spill in 1980 was
responsible for a variety of developmental effects
that indicate a demasculinization of male
alligators and "super-feminization" of females.
The effects of the spill also included detrimental
effects on hatching success and population levels.
Some research shows instances of effects on
mammals and birds. A variety of organochlorine
insecticides have been implicated in eliciting
feminization of male gull embryos, suggesting
that these effects may be contributing to
population declines and skewed sex ratios in
Western gulls in California and herring gulls in
the Great Lakes. Although the extreme
sensitivity of mink, seals, and related species to
adverse reproductive effects from exposure to
some dioxins and PCBs is well known, and
controlled laboratory studies demonstrate similar
effects on rodents, research has not established a
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link between exposure to endocrine disrupters
and population declines for wild mammalian
populations.
Reports show that humans exposed to
relatively high concentrations of certain
contaminants suffered adverse effects. However,
whether such effects are occurring in the human
population from exposure to concentrations
present in the surrounding environment, drinking
water, and food remains unclear. Several
conflicting reports have been published
concerning declines in the quality and quantity of
sperm production in humans over the last four
decades, and there are reported increases in
certain cancers in highly sex-hormone sensitive
tissues (e.g., breast, prostate, testes). Such effects
may have an endocrine-related basis, which has
led to speculation about the possibility that these
endocrine effects may have environmental causes.
However, considerable scientific uncertainty
remains regarding the actual causes of such effects.
Nevertheless, there is little doubt that small
disturbances in endocrine function, particularly
during certain highly sensitive stages of the life
cycle (e.g., development, pregnancy, and
lactation), can lead to profound and lasting effects.
The body of scientific research on human
epidemiology, laboratory animals, and fish and
wildlife provides a plausible scientific hypothesis
that environmental contaminants can disrupt the
endocrine system, leading to adverse health
consequences. A critical issue is whether
surrounding environmental levels are sufficiently
high to exert adverse effects on the general
population. To answer this question we must
understand whether or not there is a threshold
dose, that is, a dose below which exposure is
safe, or whether exposure to any level of some
endocrine disrupters carries a risk. Government
agencies, industry, and academia are currently
conducting various types of scientific studies
(epidemiology, mammalian toxicology, and
ecological toxicology) to resolve many of the
scientific questions and uncertainty surrounding
the endocrine disrupter issue. Within a few years
we hope to have a much better understanding of
the nature and breadth of this problem.
Our Approach
2)
governments, Federal agencies, public health and
environmental groups, and experts from
academia. It was truly inclusive. EDSTAC held
nine meetings from October 1996 until July
1998. These meetings were open to the public
and held in major cities across the country to
enable citizens to listen to the debate and offer
comments to the Committee.
EDSTAC formed four workgroups to deal
with the voluminous issues associated with
endocrine disrupters and reported their
recommendations back to the main committee.
They were the Principles Workgroup, the
Priority Setting Workgroup, the Screening and
Testing Workgroup, and the Communications
and Outreach Workgroup. EDSTAC submitted
its final report in August 1998 enabling EPA to
meet the deadline specified in the FQPA for
developing a screening program. The EDSTAC
Final Report contained 71 consensus
recommendations to EPA and detailed a step-
wise approach to screening chemicals that
begins with sorting, and proceeds to priority
setting, screening, and finally testing. Our
Science Advisory Board and the Federal
Insecticide, Fungicide, and Rodenticide Act
(FIFRA) Science Advisory Panel consultants
peer reviewed it in May 1998; they will conduct
a final review in early 1999. Testing is
recommended on substances that possess
endocrine disrupting properties identified
during the screening phase. EPA has now
adopted the EDSTAC's recommendations as the
basis for its endocrine disrupter screening
program and requested public comment on the
proposal in the December 28, 1998 Federal
Register. We have also published a draft
implementation plan for notice and comment.
I want to once again express my gratitude to
individuals who served on EDSTAC and its
workgroups and gave so generously of their time
and talent in helping EPA accomplish its mission
of protecting the health of the American people
and our environment. Chairing EDSTAC was
one of the most rewarding experiences of my
career at EPA.
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Sorting and Priority Setting
Endocrine Disrupters
Gary Timm
EPA formed the Endocrine Disrupter
Screening and Testing Advisory Committee
(ED STAC) to help the Agency determine
testing needs for endocrine disrupters.
EDSTAC was asked to recommend which
chemicals should be screened for endocrine
disruption effects, and how to set priorities for
reviewing these chemicals.
EDSTAC recommended that EPA consider
87,000 chemicals as potential candidates for
screening. This huge number of chemicals
includes over 600 active pesticide ingredients,
1800 pesticide inert ingredients (chemicals
having little or no ability to react), over 75,000
chemicals in U.S. commerce, covered under the
Toxic Substance Control Act (TSCA), and
thousands of other chemicals including food
additives, cosmetics, natural compounds in
nutritional supplements, and drinking water
contaminants. Although EPA has no jurisdiction
over food additives, cosmetics, and nutritional
supplements, EPA did commit to work with other
agencies to test chemicals that fall outside EPA's
jurisdiction. Because EPA cannot screen so many
chemicals at one time, the Agency will prioritize
and screen the results in batches and phases.
The first task is to develop a database to
handle all of the data required for priority setting.
The database will allow EPA to extract existing
information (production volume, uses,
monitoring data, physical and chemical
properties, toxicity, etc.) from various sources
and use it to sort and rank chemicals.
To winnow the number of chemicals from
the 87,000, EPA will sort chemicals into four
categories. These categories consist of the
following:
• Category 1, known as the Hold Category,
consists of compounds that are too big to
penetrate the skin or other membranes —
that is, polymers. Polymers are compounds
of high molecular weight derived from the
addition of many smaller molecules, or from
the condensation of many smaller molecules
when water, alcohol, or the like, is
eliminated. Also included in this category
are certain known non-toxic substances such
as inert pesticides.
Category 2 consists of the chemicals
needing screening level data to determine
whether or not they have the potential to
interact with the endocrine system.
Category 3 consists of substances known
to have the potential to interact with the
endocrine system, that is, those substances
having data equivalent to some or all of Tier
1, but in need of data for hazard assessment.
(For a description of Tier 1, see article,
"How EPA is Reviewing New PBT
Chemical Substances.") EPA plans to use
available information, High Throughput Pre-
Screening Steps (HTPS) data, and the
Endocrine Disrupter Priority Setting Data
Base to establish Tier 1 screening priorities.
EPA anticipates, however, that the quantity
and quality of exposure and effects
information will be uneven for the majority
of chemicals.
Category 4 consists of substances having
complete test data that are ready for hazard
assessment, risk assessment and possibly
risk management.
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ED STAC considered several different
priority setting approaches to determine in what
phase a chemical would be screened. In all of the
priority setting approaches examined, ED STAC
considered both exposure and effects. The
Committee rejected the approaches combining
exposure and effects to give a ranking, because it
felt that such an approach would cause EPA to
focus on chemicals where there is little
information. Chemicals having the least amount
of information should be placed at a lower
priority. The ED STAC approach recommended
that EPA group chemicals together based on like
information, or information chemicals have in
common, such as high production volume
chemicals, chemicals found in drinking water, or
chemicals that are released to the environment.
This approach avoids "apples to oranges"
comparisons, because the information used to
group chemicals is the same information that is
used to establish their ranking. EDSTAC called
these groups of chemicals "compartments." A
chemical can obviously fall into more than one
compartment. After chemicals are sorted into
compartments, they should be ranked for
attention.
Unfortunately, EDSTAC's priority-setting
efforts were incomplete due to the number of
chemicals to be addressed in a short period of
time. EDSTAC defined some compartments in
its recommendations to EPA, but most have yet
to be defined. Examples of compartments,
include high production volume chemicals,
chemicals in consumer products, chemicals
found in biological tissue, pesticide active
ingredients, formulation ingredients in
pesticides, and chemicals found in sources of
drinking water. EDSTAC specified that special
compartments be established for mixtures,
naturally occurring non-steroidal estrogens
(estrogenic substances produced by plants such
as soybeans), and public nominations. EDSTAC
felt that nominations from private citizens would
focus attention on chemical exposures at the
community level rather than the national level.
EPA accepted EDSTAC's recommended
compartment-based approach, and EDSTAC's
recommendation to continue EPA's involvement
with the public. EPA has not attempted further
specification of the compartments.
To further develop the list of priority setting
compartments, EPA plans to convene a multi-
stakeholder technical workshop in January.
Based on public feedback, and comments
received on EPA's proposed policy statement,
EPA will establish a limited number of
compartments. EPA will sort chemicals into
these compartments using existing information,
and the criteria that define each compartment.
EPA will then rank chemicals within the
compartments according to criteria related to
those for inclusion in the compartment. Finally,
the highest priority chemicals in each
compartment will form the group of chemicals
going into the first phase of the screening
program. One advantage of the phased approach
is the ability to apply what is learned during the
first phase to subsequent phases. Thus, EPA will
reevaluate the screening program and make
appropriate adjustments at the end of each phase.
This process will introduce the flexibility to
apply what is learned from both the screening
program and ongoing research. In this way, EPA
hopes to guarantee a cohesive and consistent
long-term program for endocrine disrupters.
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Screening and Testing
Endocrine Disrupters
Gary Timm
Commencing in 1995 and continuing into
1997, a series of workshops was held in the U.S.
and overseas. The purpose was to identify short
term laboratory analytical methods or assays that
could be used to screen chemicals for their
potential to disrupt the endocrine system of
humans, fish and wildlife. One of the workshops,
the mammalian workshop, looked at over 50
such assays. Some assays were in vitro
(conducted with cell cultures in glassware)
others were in vivo procedures (using live
animals). Scientists evaluated each assay based
on its:
validity — Does it measure what it is
supposed to?
reliability — Can you get the same results
from lab to lab and from time to time?
sensitivity — Can it measure active
compounds that have weak effects or only
strong ones?
suitability as a screen — Is it cost-effective
and quick and easy to perform?
A consensus of the workshop participants
concluded that no single assay is effective for
use as a screen. A battery of assays is needed.
Participants also agreed that the battery of assays
should be composed of both in vitro and in vivo
procedures. The advantages of the in vitro
procedures are increased sensitivity, lower cost
and shorter time frames. A disadvantage is that
in vitro tests do not provide feedback about the
workings of the endocrine system and provide
only limited information on an animal's ability to
metabolize or transform chemicals.
The Endocrine Disrupter Screening and
Testing Advisory Committee (ED STAC) built
upon the efforts of these workshops and
constructed a battery of Tier 1 screens to identify
the potential of chemicals to interact with the
endocrine system, and a battery of Tier 2 tests to
generate the kind of data EPA needs for hazard
assessment. EPA is proposing to accept
EDSTAC's recommendations for screening and
testing (Federal Register, December 28,1998)
for effects on three hormone systems —
estrogen, androgen, and thyroid — and will
invite public comment on this approach.
Tier 1 would consist of three in vitro assays
and five in vivo assays. To minimize the chances
of missing an endocrine-active chemical, each of
the three hormone systems is covered by at least
two assays in the battery. The first two in vitro
assays detect binding to the estrogen and
androgen receptors. These assays can run
automatically. ED STAC therefore recommended
that EPA conduct the automatic assays on 15,000
chemicals so that the Agency could use the
results to set priorities for the remaining
chemicals in Tier 1. EPA could run the rest of
Tier 1 on a smaller set of chemicals, at a
minimum, because it would take far longer to run
the full Tier 1 battery (eight assays) on so many
chemicals. EPA expects substantially fewer
chemicals than 15,000 would go through the full
Tier 1 screen. The third in vitro assay in Tier 1
(steroidogenesis) detects the potential of the test
substance to interfere with the enzymes that are
responsible for making the steroid hormones,
i.e., the two sex hormones and others that are
derived from cholesterol. If the body cannot
synthesize these hormones in adequate amounts,
or makes too much, serious developmental
consequences can result.
Of the five in vivo screens, one is a
relatively short-term assay in females that
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Screening and Testing
measures estrogenicity (the uterotrophic assay).
Another is a short-term assay in males that
measures androgenicity (the Hershberger assay).
The most complex assay is a 20-day assay in
immature females that follows them through
puberty to detect potential estrogenic effects and
thyroid effects. The frog metamorphosis assay
also detects thyroid effects since tail resorption
depends on adequate amounts of the thyroid
hormone. Fish are included in the screening
battery because they are the oldest class of
vertebrates and are the farthest removed from
mammals.
EPA is quite confident that chemicals that
test negative in the Tier 1 screening battery are
not likely to interact with the estrogen, androgen,
or thyroid systems. Therefore, chemicals that test
negative in Tier 1 would not be tested in Tier 2.
Chemicals testing positive in Tier 1, however,
will generally be required to be tested in all Tier
2 tests. Tier 2 will contain representatives of all
major types of animals. It will include testing for
reproductive effects in mammals, fish, birds,
amphibians, and invertebrates. The Agency will
use data from the mammalian reproductive study
to assess the risk to humans and to mammals that
live in the wild. Data from the other tests will be
used to assess the risk to fish, birds, and
invertebrates.
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EPA's Strategy for Priority Persistent,
Bioaccumulativef and Toxic (PBT) Pollutants
Kathy Davey
EPA has developed a draft strategy to further
reduce risks from persistent, bioaccumulative,
and toxic (PBT) pollutants. These PBT pollutants
are highly toxic, long-lasting substances that
build up in the food chain to levels that are
harmful to health in humans and the ecosystem.
Health warnings about eating fish due to PBTs in
the U.S. increased by 80% in four years, from
1,278 in 1993 to 2,299 in 1997, primarily
because states are doing a better job of
monitoring and setting protective levels. PBTs
are associated with a range of adverse human
health effects, including effects on the nervous
system, reproduction, and fetal and child
development. PBTs have also been linked to
cancer and genetic impacts. EPA is especially
interested in protecting children and women of
childbearing years, and in restoring the valuable
quality of our nation's waterways. EPA's
challenge in reducing risks from PBTs stems
from their ability to travel long distances, to
transfer easily among air, water, and land, and to
linger for generations.
The first main element of EPA's strategy is
to develop and implement national action plans
that reduce risks from select PBTs. These plans
will use all of EPA's tools, across all media.
EPA's first national action plans will be
developed for the 12 priority PBTs named in the
Canada-U.S. Binational Toxics Strategy. EPA has
already developed a draft action plan for mercury
(see article in this issue), and will be developing
plans for the remaining 11 substances named in
the Binational Toxics Strategy — aldrin-dieldrin,
benzo(a)pyrene, chlordane, DDT (+DDD+DDE),
mirex, hexachlorobenzene, alkyl-lead,
octachlorostyrene, PCBs, dioxins and furans, and
toxaphene.
The second element of the strategy is to
select more priority PBTs for future national
action plans. The third element is to stop the
flow of new PBTs into commerce. The fourth
and final element of the strategy is to develop
improved right-to-know measures of progress for
the public, so people can tell whether we are
achieving our national goals and commitments.
To date, EPA actions to reduce risks from
PBTs have largely consisted of individual EPA
offices each using their separate authorities to
control PBTs in one media (air, water, land) at a
time. What is new in EPA's PBT strategy is a truly
multi-media approach. Since these substances
move among air, water, and land, we need to use
all available tools — voluntary, regulatory,
enforcement and compliance, research, and
international — in combination with each other to
break the cycle of transferring pollutants from one
place to another. As an example, once state-based
voluntary efforts retire more mercury from
circulation and use, a national approach is needed
for what to do with the mercury. Re-using
mercury commercially is not a viable answer.
States will also need national help to address the
mercury blowing in from other countries.
Near-term actions under the PBT Strategy
are underway to prevent the introduction of new
PBTs in commerce, encourage voluntary
reduction of PBTs in hazardous waste, increase
the public's right-to-know about local sources of
PBT emissions and mercury emissions from
utilities, and evaluate fish in U.S. water bodies
for PBT contamination.
EPA cannot do this alone. We will work
closely with our regulatory partners and engage
in partnerships with industry, environmental
groups, and the public to get the PBT job done.
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Reducing PBT Chemicals in Waste
Douglas Heimlich
On November 9, 1998, EPA published in the
Federal Register a Notice of Data Availability on
the Draft RCRA Waste Minimization PBT
Chemical List. The list contains 53 chemicals
which will be the focus of source reduction and
recycling activities aimed at reducing persistent,
bioaccumulative, and toxic (PBT) chemicals
present in hazardous waste. Comments on the
Notice are due on February 16, 1999.
The List, also known as the RCRA PBT
List, includes certain PBT chemicals that may be
present in some industrial hazardous wastes
regulated under the Resource Conservation and
Recovery Act (RCRA). PBT chemicals do not
readily break down or decrease in potency after
they are released to the environment. Over time,
these chemicals are likely to accumulate in soils
or other environmental media, be absorbed or
ingested by plants and animals, accumulate in
animal and plant tissue, pass through the food
chain, and potentially cause long-term human
health or ecological problems (such as cancer
and birth defects in humans, or reduced
ecological populations). PBT chemicals are
internationally recognized as a global
environmental concern.
The Agency aims to use the List to raise
government, industry, and public awareness of
the potential effects of these chemicals in the
environment, and focus coordinated public and
private actions to reduce the generation of these
chemicals in hazardous waste by 50 percent by
the year 2005. The emphasis will be on source
reduction and recycling activities to get the job
done. The 50/2005 goal was established in the
Waste Minimization National Plan, which EPA
developed with extensive input from states,
industry, environmental groups, and private
citizens. The Plan also aims to avoid transferring
these PBT chemicals from one environmental
form to another (e.g., from air to water).
The List can be a valuable resource for state
and local governments, citizen organizations, and
individuals to promote reductions in the amount
and toxicity of PBT chemicals contained in
hazardous wastes. EPA also plans to use the List
in working with states, industry, environmental
groups and other stakeholders to identify a
variety of implementation approaches for
promoting progress toward the 2005 goal. The
List will be promoted in workshops, technical
assistance, progress reporting, developing
partnership agreements, regulatory reinvention
projects, and other venues.
The Draft RCRA PBT List is an important
component of the Agency's PBT Strategy,
which integrates all of EPA's activities focusing
on priority PBT chemicals and aims to measure
collective Agency progress on reducing uses
and releases of PBTs nationally.
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How EPA is Reviewing
New PBT Chemical Substances
Ken Moss
PBT chemical substances possess
characteristics of persistence (P) in the
environment, accumulation in biological
organisms (bioaccumulation (B)), and toxicity
(T) that make them priority pollutants because of
their potential risks to humans and ecosystems.
EPA developed a category of PBT chemical
substances by defining what it means for a
chemical to be persistent, bioaccumulative, and
toxic. The category statement includes the
boundary conditions that would determine
inclusion in (or exclusion from) the category, and
standard toxicity and environmental fate tests to
determine if a chemical fits within those
boundaries.
Chemical substances characterized as
suspected persistent bioaccumulators may need
to undergo testing on "P" and "B" endpoints
which, if confirmed, would be followed by
appropriate toxicity testing to classify "PBT
chemical substances." Establishment of this
category helps the Agency gauge the flow of
PBT chemical substances through the New
Chemicals Program and measures the results of
its risk screening and risk management work.
Defining a PBT category helps EPA to
gather additional information as needed about
persistence and bioaccumulation and tailor
regulatory requirements as appropriate to protect
human health and the environment. Depending
upon the level of certainty for the PBT properties
of a new chemical (e.g., measured vs. estimated
values), the magnitude of Agency concerns, and
conditions of expected use and release of the
chemical, control action by EPA may be needed
in varying degrees, up to a total ban on
production of the chemical.
The criteria for banning a chemical from
being produced are equivalent to those that have
been used internationally to eliminate from
commerce new chemicals that are known PBT
substances, chemicals like the polychlorinated
biphenyls (PCBs) and the pesticide DDT. For
new chemical substances meeting these criteria,
EPA's concern is higher than for other PBTs and
the Agency looks carefully at any and all
environmental releases. Because of the increased
concern, more stringent control action would be
a likely outcome, including a ban on commercial
production, until data are submitted which allow
the Agency to determine whether the level of risk
can be appropriately addressed by less restrictive
measures.
With specified controls,
EPA might allow a new
chemical categorized as a
PBT to enter the market. For
example, EPA might allow a
Premanufacture Notice
(PMN) submitter (anyone
wanting to manufacture a
"new" chemical) to
commercialize a substance
upon signing a negotiated and
legally binding consent
agreement. Stipulated in the
agreement could be annual
reporting requirements on
environmental releases of the
PMN substance and specific
limits on exposures, releases
or uses while test data are being developed.
In many cases, the PBT status of the new
chemical is ambiguous and testing is needed.
EPA has developed a testing strategy for this
category of new chemical substances which
describes test data that EPA believes are needed
to evaluate the potential persistence,
bioaccumulation, and toxicity of a PBT chemical
substance. The tests are tiered. Depending upon
the circumstances, such as magnitude of
environmental releases, results of testing already
conducted, or what we know about other
chemicals with similar chemical structures (an
approach called Structure Activity Relationships
or SARs), EPA will require additional testing in
order to screen the chemical.
on
11
-------
a PBT
EPA to
as
as
to
the
(continued from prewious page)
• Tier 1. If, based upon SAR and professional
judgment, EPA scientists identify a new
chemical as a possible PBT chemical, the
chemical manufacturer first needs to
conduct simple tests to measure its tendency
to partition towards either water or fish
tissue (scientifically described as biological
lipids or fat) and its ability to readily
degrade in the environment. Once the
chemical is dissolved in water, the organic
solvent octanol (thought to have properties
that mimic body fat) is then placed in the
test vessel and the entire two-phase (water
phase and organic phase) system is shaken
to mix everything up. After everything
settles, the amount of the test chemical is
measured in both the water and the octanol
phase. The ratio of the amount in the octanol
phase over that in the water phase is called
the octanol-water partition coefficient, or
Kow. The lower the Kow, the more likely it
is that the chemical dissolves easily in water
and therefore is available to natural
breakdown processes in the environment;
the higher the Kow, the more likely the
chemical is to partition to biological lipids
like fish tissue, where it might concentrate in
biological organisms, orbioconcentrate. If
the test result is a low Kow, or a "ready
biodegradability" test shows that the
chemical rapidly degrades (which means it
is not persistent in the environment), no
further PBT-related testing is required. If the
chemical has a high Kow and does not pass
the ready biodegradability test, the chemical
would proceed on to Tier 2 testing.
• Tier 2. In this next tier, a more sophisticated
measure of biodegradability is determined
according to a test called the "shake-flask
die-away" test, or an equivalent test. This
test measures how long it takes for the
chemical to disappear by chemically
breaking down. The potential of the
chemical to bioaccumulate (be taken up in
fish by any route, through the gills or the
gut) is determined by experimental
measurement of the bioconcentration factor.
A fish bioconcentration test is the most
convenient way to experimentally measure
bioaccumulation and refers to how well the
chemical concentrates in the fish tissue. If
the measured biodegradation half-life is
greater than 60 days and the measured
bioconcentration factor is high (greater than
1000), the chemical is expected to linger in
the environment (be persistent), and
concentrate in fish tissue. As a result, the
chemical manufacturer is then required to do
Tier 3 testing. If only one condition is met,
releases and exposure are further considered
to determine if additional testing is required.
• Tier 3. This tier looks at the chemical's
ultimate fate in the environment and toxicity
to animals up the food chain, i.e., animals that
eat fish, including birds and mammals, and
human beings. Possible toxicity tests include
long-term toxic effects on fish and water
fleas; testing to evaluate effects on other
living creatures, such as birds and organisms
dwelling in the sediment of streams and
lakes; and testing of effects such as potential
for endocrine disruption (potential effects of
synthetic chemicals on the hormone systems
of people and wildlife). Environmental fate
testing determines how the test chemical
interacts with the environment, including
transport and transformation. These kinds of
tests permit scientists to draw more accurate
and reliable conclusions about how the
chemical will act in natural aquatic
environments than is possible with lower tier
test methods, and allow EPA to screen
potentially toxic chemicals prior to entering
commerce that have, in the previous testing
tiers, been confirmed as persistent and
bioaccumulative.
This article describes a process by which
EPA screens new chemicals and decides what
controls should placed on PBT chemicals prior to
their entry into the marketplace. The process is
also applied to other new chemicals, and works
to ensure that chemical companies develop
products that are safer to human health and the
environment.
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Progress of the Great Lakes
Binational Toxics Strategy
Dan Hopkins, EPA Region 5
The Great Lakes Binational Toxics Strategy
(BNS) was signed by the United States and
Canada in April 1997. The process of
implementing the BNS did not begin until
January of 1998. At that time, the U.S. and
Canada, with suggestions from stakeholders,
drafted an implementation plan for the BNS.
The implementation plan called for the
formation of substance-specific workgroups
consisting of environmental organizations, states,
industry, tribes, and governments to address the
challenges set out in the BNS for the Level One
substances. The Level One substances are as
follows: mercury and mercury compounds,
dioxins and furans, polychlorinated biphenyls
(PCBs), hexachlorobenzene and benzo-a-pyrene,
alkyl-lead, octachlorostyrene, and pesticides. The
pesticide work group is specifically addressing
chlordane, aldrin/dieldrin, DDT, mirex, and
toxaphene. To date, there have been two meet-
ings of all BNS stakeholders, a steering group
referred to as the Forum. The purpose of the
Forum is to establish and maintain the
workgroups, assess progress to date under the
Strategy, and exchange information and ideas
leading to further reductions in these substances.
In addition to the substance-specific work
groups, an Integration Workgroup composed of
similar stakeholders has been formed to discuss
cross-cutting issues such as how to address
contaminated sediments and account for long-
range transport of the Level One substances.
Discussions about these issues included
providing incentives for stakeholders to
voluntarily undertake reductions which are then
discussed with management officials of EPA
and Environment Canada. The Integration Work
Group met in June 1998 and was scheduled to
meet again in January 1999.
Partnerships among stakeholders are
another important marker of progress in
implementing the BNS. Since the development
of the BNS, several partnerships have formed.
In the U.S., the American Hospital Association
and EPA have signed a Memorandum of
Understanding (MOU) to work together toward
the virtual elimination of mercury from hospital
waste, to provide education, and to develop a
model waste management plan. In another
partnership agreement, three northwest Indiana
steel mills, the Lake Michigan Forum, the
Indiana Department of Environmental
Management, and EPA signed an agreement to
conduct an inventory of mercury in equipment
and wastes, and to develop mercury reduction
plans. The Chlorine Institute, on behalf of its
members, committed to reduce mercury use in
the chlor-alkali industry by 50% from 1990-
1995 levels, aiming for an annual reduction in
mercury usage of 80 tons by the year 2005. Six
Ontario hospitals in Canada signed an MOU for
the voluntary reduction and elimination of
mercury. Several additional hospitals have
indicated an intention to sign this MOU.
A number of other activities related to the
reduction of the BNS Level One substances have
taken place. These activities include the
promulgation of new regulations by EPA,
reductions achieved by Great Lakes stakeholders
resulting from earlier initiatives, and EPA and
state-funded activities such as pesticide
collection programs. In addition to actual
reductions and newly formed partnerships, the
U.S. and Canada have achieved significant
strides to improve source and emission
inventories for the BNS Level One substances,
and to identify opportunities for further
reductions of many of the substances.
The
and EPA
a
of
to
the
of
13
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Update on EPA's Fish
Contamination Program
Jeff Bigler
the FCP
of the
fish
by
EPA.
State and tribal officials monitor fishing
waters and fish for contaminants and issue health
advisories to the public if fish consumption is
deemed unsafe. EPA's Fish Contamination
Program (FCP) provides technical assistance to
states, tribes, and others on matters related to
persistent bioaccumulative toxics in fish and
wildlife and associated potential health risks to
consumers. Through this program, EPA
publishes guidance documents; develops and
manages national databases; holds national
forums, conferences and training workshops;
provides grants for advisory development;
conducts special studies; develops outreach
materials; and assists in the issuance of advisories
informing the public about safe amounts offish
to eat. Since 1992, the FCP has worked closely
with state and tribal agencies to establish a
national consistency in the development and
management of advisories. It helps establish
approaches, methods, and protocols for assessing
contaminants in fish and wildlife.
The FCP has published and revised a four-
volume set of guidance documents titled
Guidance for Assessing Chemical Contaminant
Data for Use in Fish Advisories. Used together,
these four volumes provide an approach for
writing risk-based, scientifically sound, and cost-
effective advisories. Over the past eight years, the
number of states using this risk-based approach
has increased from 10 to approximately 40. FCP
continues to work with the remaining states to
achieve the goal of national consistency in fish
consumption advisories. This national consistency
goal is an Action Item included in the Clean Water
Action Plan, announced by President Clinton and
Vice President Gore.
In February 1998, the Administration
published the Clean Water Action Plan:
Restoring and Protecting America's Water,
providing a blueprint for restoring and protecting
the nation's water resources. A major premise of
the Plan is that informed citizens and officials
can make better decisions with clear, accurate,
and timely information. Beginning in 1993, the
FCP began publishing the National Listing of
Fish and Wildlife Advisories (NLFWA). This
database includes all available information
describing state, tribal, and fish consumption
advisories issued by EPA and other federal
agencies in the United States for the 50 states,
the District of Columbia, and four U.S.
territories. It has been expanded to include the 12
Canadian provinces and territories. The NLFWA
contains information provided to EPA by the
states, tribes, and Canada as of December 1997.
In addition to the development of national
guidance and database management, the FCP
organizes national conferences on chemicals in
the environment, conducts training workshops,
and sponsors the Annual State/Tribal/Federal
Forum on Contaminants in Fish. This Forum is
attended by representatives from all 50 states,
30-40 tribes, several federal agencies, and
various environmental and industry groups. The
next Forum will be held in May 1999.
The FCP is also involved with the conduct
of special studies, which currently includes
studies of subsistence villages in Alaska, the
effectiveness offish consumption advisories, and
comparative dietary risks. During 1997-98, the
FCP conducted one of the largest site-specific
fish contamination studies ever undertaken by
EPA. Fish, shellfish, and marine plants were
collected from the Cook inlet area of Alaska to
determine if oil and gas activities were affecting
the quality of the food supply. The study will
provide the information needed to characterize
health risks from fish and wildlife harvested
from Cook Inlet by members of four native
Alaskan villages dependent on marine resources
as a source of dietary food items. The study
design, methods, and protocols are based on the
FCP guidance series mentioned earlier in this
article. This human health risk assessment is part
of a larger EPA effort to characterize human
health risks from pollutants associated with
offshore and coastal oil and gas Industry practices.
EPA will issue a final report in the Spring of 1999.
The FCP is working with EPA's Office of
Research and Development (OPJ)) and the State
(continued on page)
-------
(continued from pre¥ious page)
of Wisconsin on a second study, to assess the
awareness about and effectiveness of the
advisories. The study, which is national in scope,
will use focus group techniques to interview
women of childbearing age in states issuing
mercury advisories to determine:
their fish consumption habits;
the channels by which they receive health
information;
how they prefer to receive advisory
information;
how they perceive health risk due to
consumption of sport fish; and
what they view as the central risk message
that needs to be communicated.
The study will lead to a protocol which
states and tribes may use for effectively
communicating targeted mercury fish
consumption advisories to women and children.
Based on the focus groups, EPA will determine
how to distribute intervention materials, design
an intervention tool (advisory), and then
determine if the tool is effective in lowering this
sub-population's fish consumption habits and/or
mercury body burden levels. A draft report is
expected in 1999.
The third special study, Comparative Dietary
Risk, involves the collection and assessment of
data concerning health risks and benefits of
behavior changes due to fish consumption
advisories. This study will provide a
comprehensive document on what is known
about health risks from consumption of
contaminated fish, health risks from lack of fish
consumption, health benefits of consuming fish,
general problems associated with comparisons of
these risks, and a proposed approach to evaluate
the risks and benefits of fish consumption and
other dietary food items. This research should
lead to a better understanding of the impacts that
fish consumption advisories could have on an
individual's diet. Local risk managers and
ultimately individual consumers could evaluate a
broad range of dietary information before
making decisions about whether to consume fish
from contaminated areas. Furthermore, states and
tribes may use the results to assess local
populations and conditions and tailor fish
consumption advisories to better reflect the local
conditions. EPA will hold a workshop of national
and international experts during the Winter of
1998/1999 to develop the final draft document.
Prior to completing the document, EPA will ask
the Science Advisory Board or another peer
review group to comment on the approaches and
methods included in the document.
The FCP is also involved with the
development and dissemination of outreach
materials. In collaboration with the
ATSDR, the FCP will be writing to
health care professionals nationwide to
emphasize the need to be aware, and to
ensure the public is aware, of the
possible health consequences to those
who consume contaminated
noncommercial fish (i.e., fish caught
through sport or subsistence fishing).
This effort is also part of the
President's Clean Water Action Plan.
This Plan provides a blueprint for a
new cooperative approach to identify
and solve pollution problems and to
inform citizens and officials about the
quality of water bodies, and the safety
of the fish and drinking water that come from
them, as well as the beaches that surround them.
Attached to the letters to health care providers
will be copies of the brochure, Should I Eat the
Fish I Catch?, developed by ATSDR and the
FCP to provide information to consumers about
how to reduce health risks from eating fish
containing chemical pollutants. It is part of the
Action Plan and is available in three languages
(English, Spanish, and Hmong).
Lastly, the FCP assists in the issuance of
individual advisories to ensure adequate
protection of public health. In 1997, the FCP, in
collaboration with ATSDR, coordinated the
development and issuance of the first federal fish
consumption advisory. The State of Michigan
was prepared to issue an advisory which EPA
determined did not provide adequate protection
of public health, particularly for women and
children. EPA printed and distributed a total of
1.2 million copies of the federal advisory to
fishing license holders and health care facilities
throughout the State of Michigan. In 1998,
Michigan issued a new advisory providing
adequate protection of women and children. The
FCP continues to work with other states to
ensure advisories are issued that are protective of
public health.
For more information
concerning the National
Fish Contamination
Program or for copies of
the above described
materials, contact Jeffrey
Bigler, National Program
Coordinator, phone:
202-260-1305,
fax 202-260-9830,
e-mail: bigler.jeff@
epamail. epa.gov;
or write to:
U.S. EPA (4305), Fish
Contamination Program,
401M Street SW,
Washington, DC 20460.
15
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EPA's Draft Action Plan for Mercury
Karen Maher
The
of in
the
has
the
of
the
age.
Mercury, a naturally occurring metal, moves
between the water, the air, and soil as a result of
natural and human activities. It enters the
environment from sources like coal-fired power
plants, mining and smelting of various ores, and
the disposal of consumer products manufactured
with mercury. Because it is a persistent,
bioaccumulative and toxic (PBT) pollutant, the
amount of mercury in the biosphere has been
increasing since the beginning of the industrial
age. In its organic form, methylmercury
bioaccumulates in fish and becomes more
concentrated as it moves up the food chain to
humans and other animals who eat the fish.
Mercury is the most frequent reason for fish
consumption advisories in the U.S., accounting
for 60 percent of all advisories in fresh water
bodies. To date, 40 states have issued advisories
for mercury in one or more water bodies, and 11
states have issued them on a state-wide basis.
Mercury is a well-known and long-
established neurotoxin that slows fetal and child
development and causes irreversible deficits in
brain function. Scientific debate is ongoing to
more precisely determine the level of mercury
exposure at which effects begin to occur.
Several, but not all, existing studies show
adverse human health effects at the level at
which many Americans are exposed today from
fish consumption. Tens of thousands of babies
are born each year after being exposed in the
womb to levels of mercury at which some
studies have shown adverse health effects.
The draft EPA Action Plan for Mercury is
the first of a series of such national action plans.
It is a part of EPA's draft Multimedia Strategy for
Priority Persistent, Bioaccumulative, and Toxic
(PBT) Pollutants. The Agency has reviewed
current regulations, initiatives, and programs
which manage and control mercury, and has
identified a set of cost-effective options to move
toward achieving further reductions.
Specifically, EPA proposes the following
actions, in consultation with other federal
agencies, and with the involvement of states,
tribes and other stakeholders.
• Control emissions from air point sources.
Revise the water quality criterion, and
improve measurement of mercury in water.
Seek reductions in uses of mercury and
improve information and citizens' right-to-
know.
Develop an environmentally acceptable
disposal method for mercury wastes
designated as hazardous wastes.
Seek reduction in exposure to highly
exposed populations.
• Decrease further environmental
contamination from illegal use/disposal of
mercury through focused compliance
monitoring and enforcement of mercury
restrictions and requirements.
Continue international efforts to reduce
mercury releases.
Perform and support further research on all
aspects of the mercury problem.
Support regional, state, tribal, and local
actions to reduce mercury.
For copies of the draft EPA Action Plan for
Mercury and other related documents, contact
the Pollution Prevention Information
Clearinghouse at (202) 260-1023 or access the
EPA Web site at www.epa.gov/pbt/strategy.htm.
-------
Preparing the Mercury Research Strategy
Kathryn Mahaffey and Jonathan Herrmann
According to the December 1997 Mercury
Study Report to Congress, the total annual global
input of mercury to the atmosphere from all
natural sources and human activity is 5,500 tons.
Approximately 150 tons of that amount is
emitted by human activity within the United
States. Mercury is released into the environment
as either an element (e.g., the silvery metal
released as a liquid or vapor) or as one of a
number of compounds (e.g., mercuric chloride).
Depending on a number of factors, including the
type of mercury released, its transport/deposition
pattern can result in either:
Local scale impacts (e.g., depositing within
30 miles of an emissions source);
Regional scale impacts (e.g., depositing
thousands of miles from a source over a
wide area); or
Global scale impacts, i.e., becoming part of
the global emissions pool, where it can
remain for a year before depositing on either
land or water.
Deposited mercury, particularly when it
resides in lake sediments, transforms to methyl
mercury, an organic form of mercury, which is
eventually taken up in fish. Such mercury can
then accumulate in the tissues of both humans
and wildlife (e.g., eagles, otters) if they eat
mercury-containing fish. Numerous water bodies
in the United States have fish advisories for
mercury. There are also mercury "all coastal
waters" advisories for those states bordering the
Gulf of Mexico.
In response to this situation, EPA's Office
of Research and Development is preparing a
Mercury Research Strategy with the help of
scientists and engineers from other EPA
program offices and regions. The strategy will
provide a framework
to address unanswered
research questions on
the assessment and
management of
mercury releases from
human activities and
natural sources. The
Mercury Research Strategy will
consider a number of issues related to the
following set of research themes:
Hazards of methyl mercury to human health;
Ecological effects of mercury/methyl
mercury;
Modeling and monitoring of environmental
media for mercury;
Human and wildlife exposures to methyl
mercury through the aquatic foodweb;
Control technologies for combustion sources
of mercury;
Controls for non-combustion sources of
mercury; and
• Risk communications on mercury/methyl
mercury;
EPA is currently rewriting the strategy
following an internal review this past Fall. It is
scheduled to undergo external peer review in the
Spring of 1999. Once the strategy has undergone
this review, ORD and EPA offices, in
cooperation with the greater scientific
community, will develop and implement the EPA
research plan. The plan will build on ongoing
efforts on the research themes listed above and
will support EPA's regulatory and court-ordered
deadlines for mercury.
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