United States
Environmental Protection
Agency
Research
and Development
(8101)
EPA 600-R-97-008
May 1997
http://www.epa.gov
&EPA Research and Development
Fiscal Years 1995-1996
Research Accomplishments
• -- .,
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o
The American Kestrel is one of the species of birds in the United States classified as a neotropical migratory bird. In the course
of their yearly cycle, birds like the American Kestrel may pass through a dozen or more countries, each with their own conser-
vation priorities, politics, and problems. ORD and EPA have joined Partners in Flight, a coordinated effort to maintain popula-
tions of neotropical migratory bird species. Launched by the National Fish and Wildlife foundation, the partnership includes
15 federal agencies, over 60 slate agencies, 30 private conservation groups, and 145 forest products industries, (illustration:
Keith Hansen)
Children's exposures to pollutants and their potential health effects differ from those of adults. As part of an EPA initiative,
ORD scientists research the factors that make children more vulnerable than adults to health effects from pollutants, (photo:
Steve Delaney)
Since 1990, scientists, like the one collecting samples from this lake, have been gathering data for the Environmental Monitor-
ing and Assessment Program for demonstrating concepts and assessing environmental protection programs, (photo: U.S. EPA)
The open top chamber, 12 feet tall and 18 feet in diameter, was designed in the late 1970s by scientists from EPA and the U.S.
Department of Agriculture. Used all over the United States and Europe to study the exposure of plants and trees to pollutants,
this gazebo-like structure allows scientists to monitor adverse effects under conditions close to actual light, temperature, and
relative humidity. Recently, ORD scientists used the chambers to measure the response of plants to various levels of ozone.
Data from these studies have been incorporated into the proposal for revising the secondary standard for ozone, (photo: U.S.
EPA)
Trout serve as a sensitive model for evaluating the effects of a variety of stressors on aquatic species.
Using biological alternatives to chemical pesticides—like the ladybug—can reduce exposures from water runoff and spray
drift.
Scientists with ORD's Superfund Innovative Technology Evaluation (SITE) program, the U.S. Geological Survey, and the Air
Force are evaluating phytoremediation, a process that uses plants to clean up contaminated soil and water, at the former
Carswell Air Force Station. Rows of Eastern Cottonwood trees planted at this site degrade contaminants in the soil near the
tree roots, draw contaminants in the soil up through the roots and metabolize them into harmless compounds, and transpire
them through the leaves into the atmosphere.
Cover design: David Cissel
Production design and coordination: Jan Walters and David Cissel
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To OUR READERS-
Research results from EPA's Office of Research and Development (ORD) help protect and improve the quality of the
environment for everyone, everyday. Water quality criteria developed by our scientists are used by every state in the
nation for issuing permits to discharge into lakes and rivers. Risk assessments done by our scientists are incorporated into
the standards set for the air pollutants regulated by the National Ambient Air Quality Standards. Neurotoxicity test
guidelines developed by our scientists are part of the testing requirements for screening pesticides for neurological effects.
These are but a few examples of how results from ORD's research are integral to EPA activities as well as environmental
protection efforts throughout our nation.
Our program today is based on over 25 years of environmental research, much of it done by ORD, funded by ORD, or
influenced by ORD work. From this knowledge base, and guided by our Strategic Plan, ORD is tackling the highest
priority environmental problems—those of the greatest risk, those with the greatest uncertainty associated with
characterizing risk, and those where there is the greatest need to reduce the costs and improve the effectiveness of
managing risk. In addition, all aspects of ORD's program, including research plans, products, and our organizations are
being evaluated by panels of outside scientists through our peer review program.
Understanding the science—and the scientific debates—surrounding environmental issues is critical for making sound
public policies and economic investments. To ensure that results from ORD's research program contribute positively to
such debates and to environmental protection, we must explain our efforts to many stakeholders. This report is one effort
towards communicating our science more broadly. Accomplishments from our FY1995-96 in-house program are
discussed, as is the progress we have made implementing our expanded extramural program.
ORD's program is strong—with hard work at the bench and in the field, ongoing consultation with EPA's program and
regional offices, and energetic collaboration with our colleagues in industry, academia, and other government research
organizations. We will continue to bring our science, creativity, and technical expertise to solving environmental problems
today, and in the future, by building on the scientific foundation of our work in the past.
Robert J. Huggett/Ph.D.
Assistant Administrator, Office of Research and Development
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CONTENTS
1 INTRODUCTION
5 SAFE DRINKING WATER
11 HIGH PRIORITY AIR POLLUTANTS
19 EMERGING ENVIRONMENTAL ISSUES
23 TO ECOLOGICAL
31 RESEARCH TO IMPROVE HUMAN HEALTH
41 POLLUTION PREVENTION AND NEW TECHNOLOGY FOR
ENVIRONMENTAL PROTECTION
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NTRODUCTION
EPA's Office of Research and Development (ORD) /1
is composed of three national laboratories and two
national centers with research facilities located
across the United States. The missions of the
laboratories or centers listed below each align with a
component of the risk paradigm: effects, exposure,
assessment, or management.
^ National Health and Environmental Effects
Research Laboratory (NHEERL) performs
laboratory and field research to understand
health and ecological effects of exposures to
man-made stressors and the likelihood the
effects will occur under conditions of
environmental exposure.
^ National Exposure Research Laboratory (NERL)
performs research to improve the scientific
bases for human and ecosystem exposure
assessment that are part of the risk assessment,
risk management, and compliance processes.
^ National Center for Environmental Assessment
(NCEA) serves as a national resource for the
overall process of risk assessment, conducting
assessments and developing new methods and
tools for risk assessment.
National Risk Management Research Laboratory (NRMRL) provides the
scientific basis for environmental risk management, focusing on
characterizing sources of pollution and technology for preventing and
solving environmental problems.
National Center for Environmental Research and Quality Assurance
(NCERQA) / ensures the highest quality of science possible for Agency
decisionmaking through ORD's extramural grants and fellowships, peer
review, and quality assurance programs.
1A check mark •/ indicates that an Internet address related to the subject is provided at the end of this document.
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of
NHEERL
Mid-Continent Ecology Division
NHEERL
Western Ecology Division
NERL
Characterization Research Division
Ada OK-^~"
NRMRL
Subsurface Protection and Remediation Division
Athens, GA-""'
NERL
Ecosystems Research Division
NHEERL
Gulf Ecology Division
NCEA National Center for Environmental Assessment
NCERQA National Center for Environmental Research and Quality Assurance
NERL National Exposure Research Laboratory
NHEERL National Health and Environmental Effects Research Laboratory
NRMRL National Risk Management Research Laboratory
II
NERL
Ecological Exposure Research Division
Human Exposure Research Division
NRMRL
Land Remediation and Pollution Control Division
Technology Transfer and Support Division
Water Supply and Water Resources Division
Sustainable Technology Division
r\
Cincinnati Office V
II
NHEERL
Atlantic Ecology Division
PC
NCEA
NCERQA
NRMRL
Assistant Administrator
Office of Resources Management
and Administration
Office of Science Policy
Part, 1C
NERL
Air Exposure Research Division
Air Measurements Research Division
Atmospheric Modeling Division
Atmospheric Processes Research Division
NHEERL
Environmental Carcinogenesis Division
Human Studies Division
Neurotoxicology Division
Reproductive Toxicology Division
Experimental Toxicology Division
NRMRL
Air Pollution Prevention and Control Division
NCEA
Research Triangle Park Office
i With research facilities across the country and professionals in many scientific and engineering disciplines, ORD's research program addresses a wide range of environmental science questions.
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During FY95-96, ORD built on the success of
its first Strategic Plan, implementing a strate-
gic decisionmaking process and finalizing
the more effectively organized laboratory
structure. ORD has a results-oriented man-
agement process necessary to meet the re-
quirements of the Government Performance
and Results Act. With heightened attention to
peer review, ORD has improved the quality
and credibility of its science. Partnerships
with the scientific community across the
country have been expanded through the Sci-
ence To Achieve Results (STAR) program.
And ORD has expanded its research partner-
ships with other federal agencies to leverage
total investments in environmental science.
ORD uses a risk-based strategic planning
process to set priorities among the possible
research areas. In consultation with EPA's
programs and regions and the external sci-
entific community, ORD identifies potential
research areas. The pool of potential topics
is narrowed by selecting areas that clearly
will contribute to fulfilling Agency man-
dates. ORD then applies a series of human
health, ecological health, and risk manage-
ment criteria to set priorities according to
their potential to support effective risk as-
sessment and enhance risk reduction.
Using this planning process, ORD has estab-
lished six high-priority areas that will receive
expanded attention within, the broader ORD
program. This report highlights the research
results and science activities in these six pri-
ority areas, identified and outlined in 1997
Update to ORD's Strategic Plan, April 1997:
« Safe Drinking Water
• I ligh Priority Air Pollutants
• Emerging Issues
• Research to Improve Ecological Risk
Assessments
• Research to Improve I luman I lealth Risk
Assessments
« Pollution Prevention and New Tech-
nology for Environmental Protection
These high priorities include three areas of
research on specific environmental problems
and three broadbased areas of research on
methods and approaches that will impact
many additional topics. While work in the
priority areas has been ongoing in ORD's
laboratories, the prioritization of the re-
search within ORD's program is new.
In addition, this report includes examples of
grants awarded through the STAR program
to give the reader a sense of how the extra-
mural program complements ORD's in-
house research program. Taken together, the
programs demonstrate the breadth, signifi-
cance, and potential of ORD's research.
Science To Achieve —
Grants Fellowships
Focus on Priority Environmental
Issues
The STAR Program is new, one result of
ORD's transformation to provide better sci-
ence specifically targeted to meet the needs
of EPA decisionmakers. NCERQA adminis-
ters ORD's competitive research grants and
graduate fellowship program to engage the
best scientists from this country's universi-
ties and non-profit centers in our research
program, and to ensure the highest possible
quality of science in areas of highest risk and
greatest importance to the Agency. The areas
of research funded by the program are
aligned with the priority areas of ORD's
Strategic Plan.
The four components of the STAR program
include:
* Focused Requests for Applications (RFAs)—
are targeted to specific research topics
defined by the ORD Strategic Plan and
address the science needs of EPA's
programs and regions. The program
supports investigator-initiated research
by universities and other non-profit
research institutions that complements
in-house activities.
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« Exploratory Grants—provide support for
investigator-initiated grants in broad
areas related to the Agency's mission but
not covered by RFAs—such as
environmental chemistry and physics,
and the health and ecological effects of
pollution.
* Graduate Fellowship Program—provides
support for master's and doctoral
students in environmental sciences and
engineering by recruiting the "best and
brightest" into environmental science
and technology for careers with
government, laboratories, and industry,
* Environmental Research Center Program—
provides stable funding for universities
to conduct long-term coordinated
research on complex or emerging
environmental issues. There are four
competitively established Environmental
Research Centers. •/
Since the program was launched in FY94,
NCERQA has administered two cycles of
awards with each cycle requiring an exten-
sive process for announcements, application
reviews, peer reviews, and awards. In FY95,
ORD awarded 172 new grants totaling $33
million to institutions in 42 states. In FY96,
ORD awarded 195 grants totaling $97 mil-
lion to 136 institutions in 45 states. In addi-
tion, ORD awarded 92 graduate fellowships
in FY95 and 108 graduate fellowships in
FY96.
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SAFE DRINKING WATER
Today, microbial pathogens and
the by-products of drinking
water disinfection processes are
challenging ORD researchers to
better understand the
organisms that infect—and the
processes and technologies that
disinfect—our drinking water.
More Americans are
drinking safer water
than ever before. And
yet, waterborne disease
is still a public health
risk. There were 34
outbreaks of waterborne
disease reported in
1991 and 1992, and the
1993 outbreak in
Milwaukee was the
largest documented
occurrence of disease
from a treated public
water supply in the U.S.
To disinfect a public
drinking water supply,
water system managers
use chlorine or
alternatives such as
ozone, chloramines, or chlorine dioxide. While the disinfectants reduce the
risk of getting sick from microbial organisms, some of the chemical by-
products resulting from the treatment process have been shown to cause
cancer and other toxic effects in laboratory animals. In addition, some
epidemiology studies suggest that consumption of chlorinated water may be
associated with increased rates of cancer and adverse effects to the
reproductive system in people.
These two risks from drinking water—exposure to microbial pathogens and
the by-products of the disinfection process—pose a significant challenge for
water system managers. They must use just enough disinfectant to kill
pathogens but keep the disinfection by-products at a minimum while running
the process economically.
There is still a high degree of uncertainty about how to measure microorgan-
isms in water and determine at what levels they can infect. Additionally, there
is a high degree of uncertainty about whether disinfection by-products pose a
significant human health threat. Because of the uncertainty, the widespread
human exposure to drinking water, the severity of the known effects from
certain microbes, and the potentially high costs of further regulation, this
issue is of high priority to EPA's Office of Water and to ORD's research
agenda.
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Cryptosporidium Research Focuses
on Infection and Cleanup Techniques
In April 1993, an outbreak of waterborne
disease caused by Cryptosporidium killed al-
most 100 people and made 400,000 people ill
in Milwaukee, Wisconsin. While ORD re-
searchers and engineers were working with
local officials, it became clear that better
data on the infectivity of Cryptosporidium
were needed. As a result, over the past sev-
eral years ORD has undertaken a major re-
search effort to understand and control
Cryptosporidium.
Scientists with NERL and NHEERL con-
ducted research to determine
Cryptosporidium's infectious dose inhuman
volunteers. The initial study indicated that
as few as 30 oocysts could cause illness. This
research raises many more questions that
ORD is now investigating:
• Do people develop immunity to
Cryptosporidium after multiple
exposures?
• Are other strains of the pathogen as
virulent as the one that has been studied
to date?
• To what extent are children and adults
with weakened immune systems at
greater risk for infection?
A complete picture of the relationship be-
tween dose and response for Cryptosporidium
is essential to developing an accurate assess-
ment of risks as well as determining the best
options for protecting public drinking water
supplies.
NHEERL made important advances in the
development of blood tests that detect
Cryptosporidium infection. These tests will be
used in epidemiologic studies to character-
ize exposure to Cryptosporidium from drink-
ing water.
Because Cryptosporidium oocysts are much
more resistant to disinfection than most
other waterborne pathogens, scientists and
engineers in the drinking water treatment
program at NRMRL are focusing on new ap-
proaches to control the organism in the
Like other protozoan
pathogens, Cryptosporidium
has several stages to its life
cycle. During the oocyst
stage, the oocyst wall is a
strong but flexible casing
similar to a gel cap. While
the oocyst may be larger
than the openings of the filter
used in the treatment
process, its flexibility enables
it to squeeze through the
filter and pass on through the
system. The casing also
makes it very resistant to the
chlorine or other chemical
disinfectants used for final
disinfection of drinking water.
Beads
3.5 -7.5 microns
Cryptosporidium
3.5 - 6.5 microns
InH mi Membrane Filter
WJJI 3 microns
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STAR Grants for Cryptosporidium
The Metropolitan Water District of
Southern California is developing
a cell culture assay to combine
with gene probe-based
techniques for detecting and
counting infectious Crypto-
sporidium in source and finished
water. Current detection methods
do not determine whether the
pathogens measured are capable
of infecting people.
Kansas State University is
developing gene libraries for
Cryptosporidium and other path-
ogens found in drinking water.
When made available to the
public, these gene libraries can
be used to create genetic probes
for diagnostic or environmental
testing.
drinking water system. ORD research has
shown that the organism can slip through
water filters. EPA researchers are conduct-
ing comparative tests of different water fil-
tration systems to determine optimal
removal conditions and to evaluate the ef-
fectiveness of filtration followed by disin-
fection. Several technologies suitable for
small water systems also are being evalu-
ated. This new research will help the
Agency to protect the public from further
outbreaks of waterborne disease associated
with Cryptosporidium.
basis for observed effects are needed. Scien-
tists at NHEERL are investigating the toxic
effects associated with disinfection by-
products and the toxicologic bases for the
adverse effects. In FY95, NHEERL research-
ers demonstrated for the first time that
dicholoroacetic acid, a by-product com-
monly found in disinfected drinking water,
causes liver cancer in rats. Information
from the research in this area may help to
explain how the cancer process is activated
by this chemical.
Method Identifies Disinfection By-
Products from Innovative Process
Identifying the chemical by-products from
water disinfection processes is the first step
in assessing the risk from disinfection. Sci-
entists from NERL in Athens, Georgia, and
NRMRL in Cincinnati, Ohio, have joined in
a study to identify any potentially harmful
by-products from a unique disinfection pro-
cess, that combines titanium dioxide with
ultraviolet light. Using a combination of
mass spectral and infrared techniques, the
investigation identified only one by-prod-
uct (3-methyl-2,4-hexanedione) of the tita-
nium dioxide method. As expected,
additional by-products were found when
chlorine was used as a secondary disinfec-
tant. Continuing research will extend the
identification of disinfection by-products to
permit improved risk assessments of drink-
ing water exposures.
Health Research for Disinfection and
Disinfection By-products
Several epidemiologic studies have sug-
gested a possible association between expo-
sure to disinfected water and cancer or
reproductive effects. However, the findings
have been inconsistent and causality has
not been established. Accurate assessments
of the risk posed by disinfection by-prod-
ucts and an understanding of the biological
STAR Grants for Disinfection By-Products
Pennsylvania State University is developing a method for quanti-
fying small amounts of haloacetic acid disinfection by-products
more directly than existing methods, which can be done on-site
without hazardous organic solvents.
The University of Massachusetts is developing, testing, and refining
new analytical methods for organic disinfection by-products. This
research project will also identify new disinfection by-products in
water supply samples.
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New Method Developed to Identify
Health Risks in Groundwater
In support of EPA's Office of Water, scien-
tists from NERL's Human Exposure Re-
search Division in Cincinnati, Ohio, have
developed a new method for testing
groundwater sources for microbial
contamination.
Until relatively recently, microbes in
groundwater had not been researched since
it was generally assumed that underground
water sources were protected from contami-
nation by the earth's surface. Working with
the Office of Water and the American Water
Works Association Research Foundation,
under a Federal Technology Transfer Act
agreement, scientists chose 30 sites across
the country that supply water for public
drinking water systems. ORD used this
project to evaluate a new method of testing
for viruses, which proved to be more sensi-
tive and as fast as the traditional indicators
method currently favored by water system
engineers.
Using a culturing procedure from molecular
biology methods, scientists run a "100 gallon
sample of the groundwater through a filter.
Because the pores of the filter are larger than
the pathogens, the filter is positively
charged in order to snatch the negatively
charged microbes as they pass through the
filter. The virus is scraped off the filter and
put in large bottles along with human and
animal cells. The bottles are rolled, creating
more surface area for the microbes to land
on than if the bottles were stable and in-
creasing opportunities for contact with the
cells. Microbes that land on the human, or ani-
mal cells then can be observed to determine if
they are alive and capable of infecting.
The results of the study, to be published in
late 1997, found viruses in. 23 percent of the
groundwater supplies tested and demon-
strated that the new method also could be
used for surface waters.
ORD Technical
Outbreaks of Waterborne
and Drinking Water Quality Problems
The risk of illness from drinking contami-
nated water is a major concern for consum-
ers, drinking water utilities, and state and
federal regulators. NRMRL's Water Supply
and Water Resources Division in Cincinnati,
Ohio, provides technical assistance to states
and EPA's regional offices to investigate
problems of non-compliance with regula-
tions. For example, last year ORD experts
assisted the Agency in diagnosing drinking
water problems in the District of Columbia
and devising measures to restore the integ-
rity of the system.
In addition, ORD staff have assisted the
Centers for Disease Control and Prevention
(CDCP) and states and regional offices with
investigating identified waterborne disease
outbreaks. ORD scientists and engineers
consult on analysis of water samples, char-
acterization of microbes isolated from water
samples, and associated conclusions. In the
past two years, ORD assisted CDCP as part
of its response to an outbreak of chronic di-
arrhea in a small town in Texas, the State of
Idaho in a suspected outbreak of the virus
Campylobacter in a summer camp, and the
Georgia Division of Public Health in a sus-
pected outbreak of £. coif at a swimming
pool. In addition, ORD and CDCP jointly
published a biannual summary of the re-
ported waterborne disease outbreaks in. the
U.S. from 1993 to 1994.
Water Quality Model Simulates
Drinking Delivery
The quality of drinking water can deterio-
rate as it flows from the treatment plant
through, the water distribution system to
consumers' faucets. Water quality can be af-
fected by several conditions in the system:
supply sources going on and off line, con-
tamination by cross connections, long hold-
ing times in storage facilities, bacterial
regrowth, increase in turbidity, and the
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formation of disinfection by-products. The
complexity of a water delivery system can
make it difficult to pinpoint the causes of
contamination. For example, city water
systems can have hundreds to thousands
of miles of pipe arranged in intersecting,
looped networks. Water can follow a
myriad of pathways through these sys-
tems, depending on how the system is op-
erated and what the demand for water is at
any given time. Since monitoring offers a
limited view of how well a distribution
system is working, system managers use
computer models to simulate the operation
of the distribution system.
One such computer model is EPANET. De-
veloped by ORD researchers at NRMRL,
and based on more than ten years of re-
search and field studies, EPANET predicts
how water pressure, flow rates, substance
concentrations, and the age of water
throughout the pipe network change over
an extended period of time. Besides its
state-of-the-art numerical methods, the pro-
gram uses graphics to display its simulation
results. For example, results can be dis-
played on an animated color-coded map of
the piping system to illustrate changing
conditions throughout the system.
1 - Well No. 5
2 - 50,000 Gallon Tank
3-100,000 Gallon Tank
4 - Cotton Compress Tank
5 - Nursing Home
6 - Schools
I After an outbreak of salmonellosis
in a small town, EPA researchers
used EPANET to test the theory
that the cause of the outbreak was
bird infestation of a water storage
tank in disrepair. This tank was
completely drained during a
system flushing episode that
occurred two days prior to the
outbreak.
The figure shows the percent of
water from the suspect tank
"N300"—point 3 in the diagram-
reaching various points in the
system during the flushing
episode. The circles are consumer
locations and the lines connecting
them are water pipes. The arrows
on the pipes indicate the direction
of flow. The color of each circle
represents the percent of the
consumed water that originated
from the suspect tank.
Typically, EPANET is used to
manage water quality before an
outbreak happens. For example,
water system managers might use
the model to optimize post-
disinfection within their systems,
making sure that levels of chlorine
are high enough to provide
adequate disinfecting power but
not so high as to produce
excessive amounts of unwanted
disinfection by-products.
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Two years after its release, over one thou-
sand copies of the program have been re-
quested by water utilities, consulting
engineers, and universities to be used as a
tool for studying how safer water can be de-
livered to customers. Utilities in Oakland,
Detroit, Seattle, Madrid, and Sydney are
using EPANET to model various aspects of
their distribution systems. Dozens of
smaller utilities have found EPANET to be a
simple and inexpensive way to begin study-
ing behavior within their own systems. The
American Water Works Association and sev-
eral universities are using EPANET in train-
ing workshops and courses. EPANET has
spawned several commercial software prod-
ucts that offer enhanced data handling and
graphical display capabilities.
10
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HIGH PRIORITY AIR POLLUTANTS
Besides oxygen, the air we
breathe can contain
bioaerosols—airborne particles,
large molecules, or volatile
compounds released into the air
from living organisms.
Bioaerosols can be fungi,
viruses, protozoa, antigens, and
endotoxins. To determine
whether bioaerosols may be
related to health effects such as
allergies, asthma, sick-building
symptoms, and infectious
diseases, scientists study
bacteria samples like the ones
being prepared above.
Ambient exposures to major
air pollutants—ozone,
nitrogen oxides, carbon
monoxide, particulate matter,
sulfur oxides—while regulated
by the Clean Air Act, continue
to pose human health and
ecological risks. Under the
Clean Air Act, EPA establishes
National Ambient Air Quality
Standards (NAAQS) for these
pollutants, and must
periodically review the
standards. Much of ORD's
research program in this area
is devoted to supporting the
analysis needed to review the
primary (for human health)
and secondary (for ecological health) NAAQS. The Clean Air Act places major
responsibility for implementing the standards with the states, which submit
State Implementation Plans to EPA for evaluation and approval. These plans
provide specific information on emissions in nonattainment areas and
describe actions that state and local authorities will use to attain the standard.
Consequently, the multidisciplinary research program that ORD conducts to
support the Clean Air Act affects state programs as well as federal programs.
In the last few years, ORD's research has supported the regulatory efforts of
the Office of Air and Radiation to revise the NAAQS for ozone and particulate
matter and provide better methods and models for assessing risks from these
high priority air pollutants.
11
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Criteria Document for Tropospheric
Ozone Melds Research and
Assessment for Standard
Development
The Clean Air Act requires EPA to review
NAAQS for six air pollutants including tro-
pospheric, or ground-level, ozone. Under
this legislative mandate, the current stan-
dard for ground-level ozone is being re-
viewed to determine whether it should be
changed. An important part of the regula-
tory review of the standard includes an up-
dated assessment, called a criteria
document, of the latest scientific informa-
tion on the nature and extent of health and
welfare effects from exposure to ambient
ozone.
In the most recent ozone criteria document,
Air Quality Criteria for Ozone and Related Pho-
tochemical Oxidants, July 1996, scientists from
NERL, NHEERL, and the Research Triangle
Park, North Carolina, offices of NCEA led the
review of the latest scientific data associated
with exposure to the concentrations of ozone
and other photochemical oxidants found in
ambient air. The three-volume analysis in-
cludes an assessment of health and environ-
mental effects data and the latest information
on sources, distribution, measurement, atmo-
spheric chemistry, and concentrations of
ozone, related compounds, and their precur-
sors in the environment.
STAR Grants for Tropospheric Ozone
ORD's grants program is one of several ways EPA is
contributing to the North American Research Strategy for
Tropospheric Ozone (NARSTO), a public/private sector
cooperative research effort.
The University of California at Riverside is investigating
atmospheric chemical reactions to determine the role of volatile
organic compounds in ambient ozone levels.
The University of Colorado is conducting studies to improve the
quality of analyses of atmospheric trajectory models used to
predict tropospheric ozone levels.
Portions of the scientific information and
analysis in the criteria document are based
on research conducted in the last few years
by ORD. To evaluate the primary ozone
standard (protective of human health), scien-
tists at NHEERL studied the adverse health
effects from exposure to ozone including
acute lung inflammation, changes in pulmo-
nary function, and chronic respiratory dam-
age. Collaborating with epidemiologists
from Harvard University and Mexico City,
NHEERL scientists demonstrated that expo-
sure to ozone is associated with gradual de-
creases in lung function in children. A
similar response was demonstrated in con-
trolled clinical studies, indicating that data
from clinical studies can be used to predict
ozone response in children. Other studies
demonstrated that age plays an important
role in ozone sensitivity, with responsiveness
to ozone greatest in young adults.
A particular focus of the research investi-
gated whether asthmatics are more sensitive
to ozone than nonasthmatics. In FY95, one
study showed that severe asthmatics do in-
deed appear to be more susceptible to ozone
than healthy subjects, as measured by lung
function. In another study, NHEERL demon-
strated that allergic asthmatics exposed to
ozone experience a different kind of lung in-
flammation than normal subjects. Further, it
was found that ozone exposure is signifi-
cantly related to the development of asthma
in males but not females.
For the ozone secondary standard (protec-
tive of vegetation and ecosystems), scientists
with NHEERL's Western Ecology Division in
Corvallis, Oregon, directed a national re-
search program to assess crop loss in the
United States due to exposure to tropo-
spheric ozone. The program studied 12
major agricultural crops that represent 70
percent of the farm land in the U.S. and ac-
count for 73 percent of U.S. income from
farming. This research concluded that tropo-
spheric ozone caused significant crop loss.
12
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The crop yield loss data indicate that re-
ducing ozone by 10-25 percent from 1986-
1990 levels in rural areas would save U.S.
farmers $1.7- $2.4 billion each year.
While crops are harvested annually forests
have much longer life cycles, and the ef-
fects of ozone are more difficult to assess.
ORD's research program has examined 11
tree species, chosen for their economic and
ecological significance, in exposure studies
at sites across the country. This research
provided the most important information
available in the scientific literature on the
effects of ozone on trees for EPA's 1995
ozone assessment document. These data
are useful for assessing the relative protec-
tion afforded tree species under a standard
based on crop data.
ORD scientists also characterized the effects
of ozone on forest vegetation, showing
that ozone has a profound effect on the
Essmated Three Year Lofttolly Pine
fli&tiass lass DueTn
Tropospftefic Ozone Exposure
rhizosphere (the root/soil complex) of tree
seedlings. ORD's recent research demon-
strated that ozone depresses root growth
and reduces the symbiotic association be-
tween roots and soil microbes. In addition,
ozone often lowers the amount of carbohy-
drate available, making seedlings more sus-
ceptible to nutrient and moisture stress. By
adversely affecting the rhizosphere, ozone's
impacts on forest ecosystems may be more
widespread than the previous predictions had
estimated based on conventional measure-
ments of damage to foliage.
Biogenic Emissions Modeled for
More Accurate Ozone Attainment
Plans
In the past two decades, over $20 billion has
been spent in this country on controls to re-
duce man-made emissions of volatile organic
compounds (VOCs) in order to meet the
r* Mt *
In this map, a geographic
information system (CIS)
integrates three data sets-
distribution of the loblolly pine,
estimated seasonal ozone
exposure for 1988, and
simulations of biomass response
—to illustrate the potential
percentage of biomass loss from
exposure to ozone over three
years.
The color coding of the key (left to
right) shows increase in standing
biomass of loblolly. Top to bottom,
the key shows reduction in
biomass over three years. The
darker colors point to areas at
greater risk for biomass loss
based on ozone levels and
density of loblolly trees.
ORD scientists developed this
CIS-based approach to integrate
seasonal exposure data,
biological effects data and
environmental/meteorological
data to show potential extent and
magnitude of the effects of ozone
on forests over time.
13
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NAAQS for ozone. However, the control
strategies in the eastern U.S. and on the
west coast have been hindered because of
the abundance of naturally emitted, or bio-
genie, VOCs from forests and other vegeta-
tion. In the U.S., approximately 30 million
tons of VOCs are emitted annually from bio-
genie sources compared to 20 million tons
from man-made sources. Consequently, ac-
curate estimates of emissions of smog-pro-
ducing chemicals from vegetation are
important to factor when developing cost-
effective air pollution control strategies.
Scientists with NRMRL and NERL in coop-
eration with the National Center for Atmo-
spheric Research and four universities —
Duke, Wisconsin, Washington State, and
North Carolina State — have developed a
new model that more accurately predicts
biogenic emissions. The model, called Bio-
STAR Grants for Biogenic
Emissions
Purdue University \s developing
and evaluating techniques to
quantify ambient air levels of
volatile organic compounds
(VOCs) including biogenic
VOCs. Since VOCs are major
precursors to tropospheric
ozone, real-time air quality data
will improve our understanding
of the factors that cause ozone
levels to exceed the standard.
Pennsylvania State University is
conducting studies to improve
the predictive capability of air
quality models that predict long
range transport of ozone and its
precursors.
Scientists gather data of actual
leaf emissions to validate and
improve the accuracy of BEIS2
predictions of natural ozone
precursor emissions. Scientists
use the Licor 6400, generally
used to measure water vapor and
carbon dioxide for photosynthesis
studies, to sample isoprene
emitted from the leaf of the white
oak, the single most dominant
tree species in the eastern U.S.
genie Emissions Inventory System Version 2
(BEIS2), is being used by several states to re-
vise their State Implementation Plans for
controlling ozone, and by other research or-
ganizations studying the process by which
smog is produced.
As much as 5 percent of carbon fixed by
common trees such as oaks, aspen, poplars,
willows, and sweetgum can be emitted back
into the atmosphere as isoprene, a highly re-
active precursor to smog. By measuring the
emissions of compounds such as isoprene
from leaves under a variety of seasonal and
environmental conditions, scientists have
developed models at the leaf level that have
been scaled to the landscape level using re-
mote sensing and ecological survey data.
Subsequent measurements from towers, bal-
loons, and aircraft of actual emissions from
the landscape have shown that BEIS2 is a
significantly improved model for predicting
isoprene emissions.
14
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Criteria Document for Particulate
Matter for
NAAQS
EPA also may revise the NAAQS for par-
ticulate matter (PM), In the most recent PM
criteria document, Air Quality Criteria
Document for Particulate Matter, April 1996,
scientists from NERL, NHEERL, and the
Research Triangle Park, North Carolina, of-
fices of NCEA led the review of the latest
scientific data associated "with the inhala-
tion of both fine particles (less than 2.5 mi-
crons in diameter [PM25]) and small
coarse-mode particles (less than. 10 microns
in diameter [PM10]) capable of being depos-
ited in the lower portions of the lungs.
Portions of the scientific information and
analysis in the criteria document are based
on research conducted or supported by
ORD in the last few years. For example, re-
cent epidemiological studies funded by
NHEERL of people living in cities have as-
sociated exposure to particulate matter at
levels below the current PM1()standard with
increased illness caused by lung disorders
and increased premature death rates from
heart and lung diseases. The consequence of
these findings is that particulate matter has
been estimated to cause up to tens of thou-
sands of premature deaths and many more
cases of adverse health effects in both adults
and children.
A critically important but unresolved issue
is how particulate matter produces its toxic
effect: what are the biological mechanisms
of PM toxicity and are there characteristic
features related to particle size or composi-
tion that cause the injury and damage? To
understand the mechanism by which PM
exerts its effects, animal models of cardiop-
ulmonary disease and asthma have been
developed as surrogates for adverse hu-
man lung conditions. NHEERL studies
with these animal models have shown that
PM exposure resulted in more inflamma-
tion, lung impairment, and increased
mortality as compared to normal animals.
To examine which constituents of particles
cause the effects, research has focused on
metals, which NHEERL scientists have de-
termined play an important role in causing
acute inflammatory response from PM ex-
posures. Metal composition of particles var-
ies according to the source of the emission,
and NHEERL scientists have found that the
type of genetic damage that may be in-
duced by PM also varies among emission
sources. Gene mutations, which can initiate
the cancer process, have been detected in
human lung tumors, and the type of muta-
tion has been shown to differ depending on
the source of PM exposure. This research in-
dicates that both particle composition and
emission source can affect the nature and
degree of lung damage and other health
risks.
Dosimctry research studies how much of an
agent actually gets to the area or organ of
the body where it may produce an effect. It
is important for developing models that
predict how much and where particles may
be distributed in the human lung and for
extrapolating the data from animal studies
to humans. In FY95, NHEERL studies dem-
onstrated that breathing pattern and airway
resistance, not age or gender, are the most
significant factors that affect how particles
deposit in the lung. These studies help in
identifying individuals most susceptible to
PM exposures.
Single Breath Canister Collects A
for Analysis
Scientists with NERL have developed a
new method for quickly collecting a single
alveolar breath (from deep within the
lungs) for detecting the presence of a
pollutant in the body after exposure. It is
called a single breath canister or "SBC."
Bioindicators of human exposures result in
a more accurate assessment of exposure
than measuring pollutant levels in the air
15
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In this self-administered single-
breath collection technique, the
subject exhales through a sterile
Teflon tube into an evacuated
one-liter SUMMA" polished stain-
less steel canister. While the can-
ister is held to the chest with one
arm, the hand of that arm is used
to pinch the subject's nose to
avoid entrainment of ambient air.
The subject then breathes
smoothly and lightly through the
mouth. At the end of a normal
resting exhalation, the subject
closes the mouth, opens the can-
ister valve, and continues to expel
the remaining air from deep within
the lungs. When the flow stops,
the subject shuts the canister
valve. Once in the canister, the
breath sample is stored or easily
shipped for later analysis. The re-
search into these methods was
performed, in part, with analytical
equipment developed under a Co-
operative Research and Develop-
ment Agreement between EPA
and Graseby Nutech Corporation.
that the person is breathing. The method
generally used for sampling is to take blood
samples or use complex and cumbersome
instruments to collect breath samples.
The new technique uses a small one-liter
canister (about the size of a grapefruit) to
capture a single breath. It is fast, easy, and
does not require electricity; all the subject
has to do is to breathe out into a small tube
while opening a valve. Later on, the breath
is analyzed in the laboratory. Just like the
"breathalyzer" tests for alcohol in the blood,
scientists can test for a variety of volatile or-
ganic pollutants in the breath and then re-
late the results to a blood level.
The new SBC method has several advan-
tages over previous methods. The canisters
are small and easy to transport. Most
subjects can give a sample successfully on the
first try. The small inlet tubes are inexpensive
and disposable so no disinfection of equip-
ment is required, and SBC is less invasive
than taking a blood sample. Scientists have
already demonstrated this method for mea-
suring chloroform exposure from chlorinated
municipal water (showering and swimming),
exposure to benzene and vinyl chloride from
contaminated well water, exposure to gaso-
line additives from filling a car gas tank, and
exposure to tobacco smoke in public places.
The SBC also is being used by the U.S. Air
Force to measure exposure to the partially
burned fuel from cold starts of fighter planes,
by the Canadian Health Directorate as part of
a multimedia exposure study, and by the
Australian Defense Department for assessing
exposures in new submarines.
STAR Grants for Particulate Matter
New York University Medical
Center is using existing ambient
databases for three U.S. cities
to evaluate the roles of various
PM components on human
mortality in the total population
and in potentially sensitive
populations.
Harvard University School of
Public Health is conducting
studies to identify the size
fractions of ambient PM levels in
urban air that are most highly
associated with lung function
performance in children.
The National Jewish Center for
Immunology and Respiratory
Medicine is studying the
relationship of submicron
particulate matter from
combustion with several indices
of asthma.
16
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Size Selective Inlet
(PM 2.5)
Roof
Duct to Concentrator —
1st Concentrator Stage
(2.5 -0.1 microns)
2nd Concentrator Stage
(2.5 -0.1 microns)
3rd Concentrator Stage
(2.5-0.1 microns)
\\\\M
Animal -
Exposure Chamber
ANIMAL SUBJECTS
Total Flow
Technology for Concentrating "Real
World Atmospheric Aerosols" A
Major Breakthrough for Laboratory
Particulate Matter Exposure Studies
In cooperation with the Harvard University
School of Public Health, ORD scientists
with NERL and NHEERL have invented a
new instrument for collecting, concentrat-
ing, and delivering atmospheric particles
for use in laboratory exposure studies. The
development of a unique 0.1 micron
cutpoint virtual impactor now makes it pos-
sible to concentrate ambient particulate
matter in the size range of 0.1 - 2.5 microns.
Coarse Particle
Trajectory
In this exposure chamber, a
conventional impactor removes
particles larger than 2.5 microns
from the air sample while smaller
particles escape collection. The
smaller particles then pass
through three virtual impactors.
Each impactor concentrates the
particles so that by the time the
ambient aerosol reaches the test
subjects in the exposure chamber
the particle concentration has
increased by a factor of 25-30.
The particles maintain their
physical and chemical
characteristics. With this method,
scientists can determine the
toxicity of ambient particles by
performing dose-response
assessments of different
exposures in real time.
Diagram of virtual impactor
process that occurs at each of the
three concentrator stages above.
Minor Flow
17
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This system is a major breakthrough for use
in inhalation exposure studies for two rea-
sons. First, it keeps the complex chemical
and physical make-up of the mixtures in-
tact. Second, it enables particles concen-
trated by a factor of 30 to be tested in
laboratory studies, thus providing more of
an opportunity to observe dose response re-
lationships. Past animal and human labora-
tory exposure studies typically used
laboratory-generated aerosols. The new
technology is a major step forward for stud-
ies of the causality of the associations of PM
and mortality and morbidity.
18
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EMERGING ENVIRONMENTAL ISSUES
A major role for ORD is to
look beyond the obvious
problems of yesterday and
today to identify and assess
issues just over the horizon;
we must determine the
potential risks that these
issues pose and work to
solve them. Often, however,
few data exist to support
assessments of emerging
issues. Consequently, ORD's
challenge is to work with
others or take a leading role
to develop data and methods
for credible decisions in
areas of significant
uncertainty.
In the 1997 Update to ORD's Strategic Plan, April 1997, endocrine disrupting
chemicals have been identified as an emerging environmental issue. Based on
the potential scope of the problem, the possibility of serious effects on the
health of populations, and the persistence of some endocrine-disrupting
chemicals (EDCs) in the environment, this area has been designated a high
priority for ORD research. ORD scientists have been researching in this area
for several years. Because there are many unanswered questions about the
nature and severity of the problem, ORD's research currently focuses on
developing methods for characterizing the hazards and risks of EDCs,
quantifying exposure levels, determining their fate and transport in the
environment and developing extrapolation tools. The following research
highlights illustrate ORD's contributions to the international scientific debates
surrounding EDCs and to the Agency's mandated efforts to evaluate
chemicals and pesticides for adverse effects.
The seemingly increased occurrences of deformed amphibians in the U. S.,
while not yet a major priority for ORD's research program, is another emerging
environmental issue. ORD scientists with expertise in this area have been
involved in discussions and are engaged in researching the many scientific
questions that are arising from the increased sightings of deformed frogs. The
second highlight details recent ORD's efforts in this area.
19
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Ca** = calcium ion; SH = steroid hormone in blood or cytoplasm;
PH = peptide hormone; PK = protein kinase; R = steroid hormone
receptor; SRE = steroid response element.
Research Milestones Reached on
Endocrine Disrupting Chemicals
The endocrine system helps guide the devel-
opment, growth, reproduction, behavior and
other bodily functions of animals and hu-
mans. The system primarily includes the pi-
tuitary, thyroid, pancreas, adrenal, and the
testes and ovaries as well as the hormones
the glands produce. The hormones act as
chemical messengers, traveling through the
blood to tissues and organs, where they can
bind to specific cell sites called receptors. By
binding to receptors, hormones trigger vari-
ous responses in the tissues containing the
receptors.
An endocrine disrupter is an external agent,
such as a chemical, that interferes in some
way with the hormones. An agent might dis-
rupt the endocrine system by affecting any
of the various stages of hormone production
and activity, by binding to hormone recep-
tors, or by interfering with the natural break-
down of hormones.
This diagram illustrates several
ways in which an endocrine
disrupting chemical can affect the
function of cells within the body.
The classical effect is illustrated
by pathway 1, in which the
chemical enters a cell, binds to a
receptor (e.g., the estrogen
receptor) and moves to the
nucleus where the complex
causes specific genes to be
turned on or off. Chemicals also
may act on receptors on the
surface of the cell (pathway 2) to
alter the production (pathway 3) or
release (pathway 4) of
endogenous hormones into the
blood. The altered level of
hormone in the blood would then
affect the function of other cells
that have hormone receptors.
Finally, some endocrine disrupting
chemicals can affect the
movement of ions into, or out of,
the cell, with subsequent changes
in cellular processes (pathway 5).
Environmental chemicals that
operate by each of these
pathways have been identified.
STAR Grants for Endocrine Disrupting Chemicals
The University of California-Davis is developing a short-term animal model to identify
and characterize potential EDCs.
Boston University researchers are developing a test system for assessing the effects of
EDCs on sperm production.
Duke University is developing a vertebrate animal model for developmental genetics
analysis.
Mississippi State University is studying if PCS exposure during gestation and nursing
can affect the ability of offspring to metabolize internal hormones and EDCs and
whether this effect causes abnormal sexual development.
Emory University is studying a group of women and children in Michigan who were
exposed inadvertently to substantial levels of polybrominated biphenyls in 1976 to
determine if the exposure disrupted the endocrine system.
Bowman Gray School of Medicine is studying the effects on the brain and reproductive
system of gestational and neonatal exposure to plant estrogens found in food soy
products.
20
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A variety of chemicals, including pesti-
cides, have been found to cause endocrine
disruption in laboratory animal studies.
Scientists have hypothesized that effects
seen in laboratory studies may also occur
in wildlife and in human beings in re-
sponse to environmental exposures. Re-
search findings and observations have
caused concern about the potential long-
term effects of exposure to EDCs.
ORD scientists at NHEERL and NCEA
have been in the forefront of research into
EDCs. This work supports Agency man-
dates to evaluate chemicals and pesticides
for toxicity as well as requirements of the
Food Quality Protection Act and the Safe
Drinking Water Act to screen substances
for endocrine effects.
During FY95, a landmark paper published
by scientists at NIIEERL challenged the pre-
vailing scientific notion of endocrine disrup-
tion. Scientists found that some environ-
mental chemicals are potent anti-androgens
(substances that inhibit the action of male
hormones), and not environmental estro-
gens as previously thought. Exposure of
rats to these chemicals demasculinized
male offspring such that they displayed un-
descended testes, retained nipples, and de-
layed onset of puberty. These effects are
consistent with activation of the androgen
receptor. When these data were combined
with observations of altered sex differentia-
tion in male rats exposed to a fungicide
whose metabolites inhibit binding of the
androgen response elements on DNA, it
became apparent that anti-androgens exist
in the environment and that they can cause
developmental effects. NHEERL scientists
recently demonstrated that these chemicals
also bind to the human androgen receptor.
Publication of these important findings has
contributed to the scientific community's
widening its research focus to include stud-
ies of anti-androgens.
As part of the research program to develop
screening tests, NHEERL scientists are inves-
tigating how chemicals affect the endocrine
system and determining the best indicators,
or biomarkers, of early response to EDC ex-
posure. In FY96, NHEERL reported the dis-
covery of a protein in sperm membrane in
the male rat that appears to be a biomarker
for fertility. This protein, also common to hu-
mans, is altered when, exposed to chemicals
that disrupt the endocrine system and the ef-
fect is highly correlated with reduced fertil-
ity. The findings have received widespread
commercial interest and are the subject of a
recent EPA patent application. Currently, sci-
entists are attempting to develop an anti-
body to this sperm biomarker that can be
used to screen, chemicals for endocrine dis-
rupting activity and reduced fertility.
Under the auspices of the Risk Assessment Fo-
rum, an Agency-wide workgroup has com-
pleted a report that reviews key scientific
findings to date, Special Report on Environmen-
tal Endocrine Disruption: An Effects Assess-
ment and Analysis.
-------
A
This over-endowed leopard frog
was among some two hundred
frogs gathered by scientists with
the Minnesota Pollution Control
Commission / in August 1995.
Of the frogs collected in this
sample from the Ney
Environmental Learning Farm in
La Sueur County, Minnesota, two-
thirds were found to be deformed.
The majority had missing,
incomplete, or contorted limbs,
while this frog had two extra hind
legs. Scientists suspect that the
extra legs were immobile so this
frog would have had an extra load
to carry around. Its survival is all
the more mysterious because it
would have had to drag these legs
around while trying to find food.
ORD Sponsors Workshop on Science
Issues Surrounding Amphibian
Deformities
Over the last several years, nature lovers,
wildlife biologists, and even school-age chil-
dren have been reporting sightings of de-
formed frogs—frogs with missing limbs, too
many limbs, or withered and misshapen
limbs. Among scientists who have been re-
searching the increased incidence of defor-
mity there is agreement on only one point: an
alarming number of deformed frogs are being
found. And, there is only speculation about
what could be causing the deformities.
Scientists at the Mid-Continent Ecology Di-
vision of NHEERL in Duluth, Minnesota,
along with the Minnesota Sea Grant and
Natural Resources Research Institute of the
University of Minnesota, sponsored a work-
shop in September 1996 to discuss the sci-
ence issues surrounding amphibian
deformities.
Since there are no historical data on the inci-
dences of amphibian deformities, the num-
ber of incidences today cannot be compared
with what may have occurred in the past.
However, several very experienced herpe-
tologists at the workshop did note that if the
deformities being reported now had been as
prevalent in the past, they would have ob-
served deformed frogs in their field studies.
Several hypotheses for the cause of the phe-
nomenon were discussed at the workshop as
well as the many questions that need to be
answered.
One such question is, "Where are the de-
formed frogs?" Because there has not been a
systematic field sampling for deformed
frogs, scientists are uncertain about the geo-
graphic distribution of the problem. Partici-
pants at the workshop agreed that
systematic sampling by region needs to be
conducted to better characterize the prob-
lem. Although data are being collected by
state agencies, it is difficult to do regional or
national analysis since the data are not avail-
able in one place. Consequently, ORD, EPA's
Regions 4 and 5, and the U.S. Geological
Survey are establishing a national reporting
center. The center will compile and analyze
data collected by state agencies to determine
the geographical significance of the data and
to formulate hypotheses for what might be
causing the deformities.
22
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RESEARCH TO IMPROVE
ECOLOGICAL RISK ASSESSMENT
Ecosystems provide
valuable renewable
resources and services
such as food, water storage
and flood control, wood for
construction, biodegrada-
tion and removal of
contaminants from air and
water, pest and disease
control, and moderation of
climatic extremes. If these
benefits are impaired by
man-made environmental
stressors, they must be
replaced at great expense
by civil works, man-made
chemicals, and increased
use of non-renewable
energy supplies.
We have made considerable progress in reducing the most egregious harm to
the environment from air and water pollution but much remains to be
understood.
Ecological research can significantly reduce the uncertainties surrounding
decisions made about the use and protection of our ecological resources. The
challenge in this area is to better understand the multiple stresses that can
affect multiple endpoints at multiple scales. The goal of this research program
is to develop the scientific understanding necessary to measure, model, and
maintain or restore the integrity and sustainability of ecosystems now, and in
the future.
Scientists use a test organism,
like the large water flea, to
determine how much of a
chemical is toxic to aquatic life. In
ORD's Mid-Continent Ecology
Division in Duluth, Minnesota, the
chemical is diluted to provide a
series of concentrations. The test
organisms are added to each
container to determine the level of
pollutant that produces toxic
effects.
23
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The Waquoit Bay Watershed
covers 21 square miles on the
south shore of Cape Cod,
Massachusetts. The watershed
includes freshwater streams and
ponds, saltwater ponds and
marshes, pine and oak forests,
barrier beaches, and open
estuarine waters.
Decreased water flow and velocity
in the Mid-Snake River Watershed
permit the growth of aquatic
nuisance plant species. Cold fish
species, including trout and
sturgeon, lose critical habitat for
spawning and their food base in
these environments.
In the Middle Platte River
Watershed, resident and
migratory birds need open
sandbars and shallow water for
nesting and roosting. Reduced
river flows have changed the
characteristics of the river,
allowing shrubs and trees to
colonize sandbars. This forms
islands surrounded by deep water
and decreases critical habitat for
these birds.
Ecological Risk Assessment
Guidelines Proposed
In September 1996, EPA published the Pro-
posed Guidelines for Ecological Risk Assessment
(EPA 630-R-95-002B), the first Agency-wide
ecological risk assessment guidelines.
These proposed guidelines, developed by a
technical panel under the Risk Assessment
Forum, are intended to improve the quality
and consistency of EPA's ecological risk as-
sessments. The Proposed Guidelines expand
upon the widely used 1992 Framework for
Ecological Risk Assessment, as a next step in a
continuing process of EPA's ecological risk
guidance development.
Ecological risk assessment is a process for
organizing and analyzing data, information,
assumptions, and uncertainties to evaluate
the likelihood that one or more stressors are
causing (or will cause) adverse ecological ef-
fects. Ecological risk assessment provides
risk managers with a tool for considering
available scientific information when select-
ing a course of action, in addition to other
factors that may affect their decision (e.g.,
social, legal, political, or economic consider-
ations). A major theme of the proposed
guidelines is the interaction between risk
assessors and risk managers at the beginning
and end of the risk assessment process to
ensure that the results of the assessment can be
used to support a management decision.
Case Studies in Ecological Risk
Assessment Demonstrate Watershed
Level Resource Planning
The Risk Assessment Forum and NCEA
are working with the Office of Water to ap-
ply the principles outlined in the Proposed
Guidelines to improve decisionmaking in
five watersheds. These ecological risk assess-
ment case studies were undertaken to ad-
dress local concerns and analyze stressors
and resulting ecological effects. The five case
study demonstrations are in the following
watersheds: Waquoit Bay in Massachusetts;
Big Darby Creek in Ohio; the Clinch River in
Tennessee and Virginia; the middle segment
of the Platte River in Nebraska; and the Mid-
Snake River in Idaho. Each of the five case
studies is being developed by an interdisci-
plinary, interagency team of scientists and
natural resource managers and involves a
different set of problems associated with
managing the watershed as a resource. This
case study approach has brought together
numerous organizations to analyze an envi-
ronmental problem, and it has stimulated
public awareness and participation in
decisionmaking.
Even though all the assessments are still go-
ing on, valuable lessons about the process
have been learned already. The planning and
problem formulation stages of the assess-
ments forced managers to reflect carefully on
their goals for managing the watershed and
how the goals may have differed from the
interests of local industry and community
24
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STAR Grants for Ecological Risk
Assessment
The science of developing and
using indicators of ecological
condition is complex. There are
multiple resource types
(wetlands, rivers, estuaries) in
different spatial scales (local,
regional, and national) and
different levels of biological
organization (populations,
communities, ecosystems).
Since no one indicator can
signal the condition of an
ecosystem, suites of indicators
need to be developed. The
following are examples of
previous grant awards in this
area that will supplement
results from research grants
awarded this summer under the
$10 million RFAfor FY97 on
Ecosystem Indicators:
University of Georgia Research
Foundation is developing
simple, inexpensive, and rapid
methods for assaying and
monitoring the health of salt-
marsh ecosystems in the
southeastern United States.
Florida Department of
Environmental Protection/
Florida Marine Research
Institute is examining the
spatial-scale dependence and
sample size effects on the
variability within populations of
seagrass, as well as
determining the most effective
protocol for assessing the
ecological condition of turtle
grass and adjacent
ecosystems.
Iowa State University is
researching local biodiversity
patterns in the Greater
Yellowstone Ecoregion and
assessing the accuracy of
remote sensing data for
indicating ecosystem change.
Nonpoint source pollution,
including the orange acid mine
drainage in this photograph, has
been identified as the most severe
cause of water pollution in the
Clinch River Valley.
The presence of such sensitive
species as the colorful rainbow
darter indicates the exceptional
quality of the Big Darby Creek
Watershed. These darters require
clear water to see their prey and
sediment-free gravel for their
nests.
groups. The process generated vast and di-
verse amounts of information on resources,
stressors, and concerns, which in turn
helped to identify important issues that
would not have surfaced in less systematic
evaluations. These case studies offer great
potential for demonstrating the use of eco-
logical science for resource planning.
25
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Highest
Lowest
Because the Chesapeake Bay
Watershed is home for many
wildlife species, understanding
how the landscape is viewed by
different species at different
scales is important for measuring
how the change in land cover may
affect wildlife. In this map, the
surface area is divided and rated
for interior forest habitat potential.
Atlas Demonstrates Landscape
Characterization Principles
Understanding the impacts of landscapes
and land use on ecological resources is
critical to filling gaps in the science under-
pinning ecosystem protection. One ap-
proach to understanding these relation-
ships, landscape characterization, is being re-
searched by ORD and its collaborators.
Landscape characterization relates the
landscape—its composition, size, and spa-
tial patterns—to ecological resources.
Changes in the composition and pattern of
a landscape can significantly influence the
conditions of a watershed that are usually
considered important by the people who
live in the area: productive forests; diverse
wildlife; resistance to floods; and abundant,
high quality water.
ORD has been conducting research in a
number of different areas to better under-
stand the ecological processes that occur in a
watershed. As the science and databases
build with information and more sophisti-
cated techniques of analysis become avail-
able, the size of the geographic area that can
be evaluated becomes larger. In 1996, scien-
tists with the Characterization Research Di-
vision of NERL in Las Vegas, Nevada, and
their collaborators with the Tennessee Valley
Authority, Oak Ridge National Laboratory,
STAR Grants for Ecological Risk Assessment
Johns Hopkins University is developing and testing an integrated ecological
assessment methodology for the Great Lakes.
The University of Colorado is developing prototype methods and tools for
analysis of multi-scaled ecological data.
The University of Guam is improving techniques used for assessing the
health and sustainability of coral reefs and developing protocols and
guidelines for biomonitoring, restoration, and mitigating disturbances caused
by humans.
26
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and the Desert Research Institute published
A Landscape Atlas of the Chesapeake Bay Water-
shed. The document illustrates several prin-
ciples of landscape ecology and
demonstrates their potential application for
watershed management. Landscape analy-
sis can be used to set priorities as well as to
organize in-depth assessments of particular
issues. In a multi-scaled regional assess-
ment, broad questions are asked at the land-
scape scale, and detailed questions are
asked at finer scales. Using landscape scale
analysis as a "coarse filter" sets the back-
drop and identifies relative priorities for a
region.
ElAP Complement
of the Program
Since 1990, ORD's Environmental Monitor-
ing and Assessment Program (EMAP)
-------
Starting with a satellite image
called a Landsat Thematic
Mapper, scientists produce a new
map by color coding the elements
of a landscape according to land
use. For example, in this map of
New York and New Jersey, water
bodies such as the Finger Lakes
are blue, species of vegetation
are shades of green, and urban
areas are rust and orange.
Through the MRLC, maps such as
this one can be used by federal,
state, and local governments for
answering questions about
changing landscape conditions.
local agencies. SCB uses elements of EMAP
to provide data on trends in large-scale,
long-term physical and biological processes.
This regional demonstration will help to dis-
tinguish environmental effects caused by
natural occurrences from effects caused by
human activities.
Multi-Resolution Land Characteristic
Consortium
Since the Multi-Resolution Land Character-
istic Consortium (MRLC) •/ was formed
three years ago, EPA, the Department of the
Interior, the National Oceanic and Atmo-
spheric Administration, and the U.S. Geo-
• Woody Wetland
Emergent Wetland
! Quarry/Strip Mine/Gravel Pit
Transftbnal Barrier
Bare Itock/Sand
I Open Water
logical Survey have been pooling resources
to purchase satellite data, to process the data
into formats that are useful for environmen-
tal protection and resource management,
and to set up a distribution system that
makes the information available at a lower
cost than if each of the agencies were to pur-
chase it themselves.
While various federal and state agencies have
used satellite data in the past, the MRLC
started the momentum for a coordinated
approach to using the data and to providing
the imagery at a lower cost to users. It is es-
timated that the consortium could save the
government $30 million in purchasing costs
and preparation of data, including archiving,
data management, and distribution.
The consortium is providing its members
enhanced satellite images—digital imagery
and land cover maps—that illustrate the
natural landscape of the continental U.S.
These images provide a common baseline of
information that can be used by agencies to
answer questions about changing landscape
conditions that relate to their programs.
For example, an interpretive landscape atlas
is being used by EPA's Region 3 in its efforts
to restore the Chesapeake Bay. The National
Oceanic and Atmospheric Administration's
Coastal Change Analysis Program is using
the images to map coastal areas and watch
how they change over time, analyzing how
changes in land cover (such as urban devel-
opment) affect aquatic life and the fishing
industries in coastal regions. The National
Water Quality Assessment program of U.S.
Geological Survey is using land cover maps
to asses the extent to which natural vegeta-
tion impacts the quality of surrounding wa-
ter bodies.
As data are acquired and the maps are de-
veloped, they are added to the MRLC
archive. The consortium is increasing the
number of federal participants and plans to
buy more recent data to increase the size
and timeliness of the archive.
28
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Models-3: State-of-the-Art in
Multimedia Modeling
Models-3, developed by NERL in coopera-
tion with other federal agencies, is a state
of-the-art environmental modeling system
that uses the advances in high performance
computing technology to integrate fate and
transport models developed for individual
media such as air and water. The system is a
computer framework that enables users to
combine different scientific models, from
different computer environments, and dif-
ferent computer programs to model envi-
ronmental conditions.
For example, the first version of Models-3
combined models for simulating ground
level ozone, acid deposition, visibility and
particulate matter to predict urban to re-
gional scale air quality. As lessons were
learned from the first version, improve-
ments were made and another application
for the Models-3 framework was devel-
oped. This model, illustrated here, simu-
lates nitrogen deposition in the Chesapeake
Bay watershed. Three models—acid deposi-
tion, watershed, and nutrient loading—
predict the sources, movement, and fate of
nitrogen in the air, land, and water of the
region. These predictions can be used by re-
gional environmental managers to develop
risk management options for restoring the
Chesapeake Bay.
Watershed Modeling System
Scientists at the Ecosystems Research Divi-
sion of NERL in Athens, Georgia, have been
working on models that predict the circula-
tion, distribution, and properties of water at
the watershed level. One such effort is the
Watershed Modeling System (WMS). Devel-
oped in cooperation with the U.S. Army
Corps of Engineers, WMS is one of the next
generation of predictive watershed hydrol-
ogy models.
An unexpected use for the model came
about when the U.S. Army joined the peace-
keeping mission in Bosnia. In order to plan
troop and equipment movements through
the territory assigned to U.S. forces, the
Corps needed the latest information on land-
scape conditions surrounding the Sava River,
Bosnia's northern border with Croatia.
The Corps used data from the daily over-
night runs of WMS to help locate the best
approaches of the first pontoon bridge used
Three models—acid deposition,
watershed, and nutrient loading-
are integrated in the Models-3
framework to predict the sources
of nitrogen in the Chesapeake Bay
Watershed, and nitrogen's fate in
the air, land, and water of the
region.
29
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by US/NATO forces to cross the river into
Bosnia, Set up for the Sava's 22,000 square
mile "watershed and using only data ob-
tained on the Internet and through satellites,
the first runs of the model predicted the
river's stage height within. 1 meter of its ac-
tual height. Subsequent fine-tuning of the
model, "which included data obtained from
the old Yugoslav Ministry of Water, pro-
duced even more accurate predictions that
were used to locate and construct the second
pontoon bridge over the Sava and to locate
dry emplacement areas for troops, armor,
and artillery,
Closer to home, and with local data, WMS is
being used to predict nitrate levels from sep-
tic tank waste contaminating ground water
in La Plata County, Colorado, WMS pro-
vides a flexible and accurate representation
of the site "with its complex hydrogeology
and potential for water quality degradation.
The model will be used by county officials
making land use decisions brought on by a
development boom.
30
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RESEARCH TO IMPROVE HUMAN
HEALTH RISK ASSESSMENT
Health risk assessment is the process EPA uses
to identify and characterize environmental health
problems. ORD's research to improve health risk
assessment addresses major deficiencies and
uncertainties in health risk assessment (including
both problem- or agent-specific risk assessment,
and cross-cutting or generic risk assessment).
ORD's research to improve health risk
assessment includes studies and projects in each
area of the risk assessment paradigm, for
example:
• Develop models that trace the forward and
backward relationships between sources and
total exposure to better characterize the source-
exposure relationship.
• Develop methods and models for estimating
dose to target tissues to better understand the
exposure-dose relationship for pollutants from
each pathway.
• Develop screening methods to set testing
priorities to improve our ability to detect
hazards.
• Develop quantitative models for predicting
tissue and organism response to target tissue
dose to reduce uncertainty in extrapolations.
Ultimately the results of the research will enhance
risk assessments to support national
environmental goals, such as safe drinking water,
safe indoor environments, clean air, and safe food. Because of the broad
applicability of improved methods for health risk assessment to many user
communities, research to improve health risk assessment is a high priority for
ORD's research agenda.
Using an electron microscope,
scientists examine tissue damaged
by chemicals for neurotoxic effects.
(photo: Congressional Office of
Technology Assessment)
31
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EPA Proposes Revised Guidelines for
Cancer Risk Assessment
In April 1996, EPA published The Proposed
Guidelines for Carcinogen Risk Assessment. •/
These proposed guidelines, the result of a
cross-agency effort under the Risk Assess-
ment Forum, will replace the 1986 Guidelines
for Carcinogen Risk Assessment (51 FR 33992)
when final.
Since the publication of the 1986 cancer
guidelines, scientific understanding of car-
cinogens has improved substantially. Today,
many laboratories are moving toward add-
ing new test protocols in their programs di-
rected at mode of action questions. The
proposed guidelines provide an analytical
framework that allows for the incorporation
of all relevant biological information, recog-
nizes a variety of situations regarding cancer
hazard, and is flexible enough to allow for
consideration of future scientific advances.
STAR Grants for Cancer Risk Assessment
The University of Arkansas for Medical Sciences, the University of
Colorado Health Sciences Center, and the Oregon Health Sciences
University are researching the role of inter-individual genetic
variation in human susceptibility to cancer, including cancers of the
colon, rectum, and throat. Results should help EPA revise its cancer
risk assessment guidelines to account for genetic variabilities.
The Hutchinson Cancer Research Center is developing a biologically
based model for assessing the potential cancer effects from specific
pollutant exposures to improve current cancer risk models.
Progress Continues Towards
Finalizing EPA's Dioxin
Reassessment
EPA, led by NCEA, has been engaged in a
major effort to reassess risks associated with
dioxins. A draft of the assessment entitled
Health Assessment Document for 2,3,7,8-
Tetrachlorodibenzo-p-Dioxin (TCDD) and Re-
lated Compounds was reviewed by EPA's
Science Advisory Board (SAB) in the Fall of
1995. In response to the SAB's comments,
NCEA began revising two key sections of
the report: the draft risk characterization
and the dose-response modeling chapter.
Writing teams made up of scientific experts
in the study of dioxin and related com-
pounds from academia, consulting firms, in-
dustry, and federal and state agencies,
including EPA, developed new drafts of
both sections of the report. Following pre-
liminary external review, the drafts are be-
ing reworked. The two sections will undergo
external peer review and another review by
the SAB in Summer 1997. It is expected that
the reassessment will be finalized and avail-
able to the public before the end of 1997.
An important part of the dioxin reassess-
ment effort is the Dioxin Exposure Initiative,
a multi-phase research program to reduce
uncertainties in dioxin exposure assessment,
provide information for developing an
Agency-wide Dioxin Exposure Reduction
Strategy, and provide input to the document
Estimating Exposures to Dioxin-Like Com-
pounds. Several projects of this initiative
have been completed in FY96, and the re-
sults will be incorporated into the exposure
analysis of the reassessment.
NCEA has developed a preliminary inven-
tory of measurements of multimedia emis-
sions from combustion sources, industrial
sources, chemical manufacturing, and natu-
ral/biogenic sources. The inventory is a pri-
mary reference for the national dioxin
estimates from known sources in the U.S. It
will be available to the public on the Internet
in 1997, for use in analyzing emissions
trends of sources.
With the U.S. Department of Agriculture,
NCEA is coordinating three separate sur-
veys—for beef, pork, and poultry—to evalu-
ate the occurrence and levels of dioxins in
animals at the point of slaughter production.
The beef survey has been completed. The
results have been published in Chemosphere
and were presented at the 16th Interna-
tional Conference on Dioxin and Related
Compounds held at the University of
Amsterdam, The Netherlands. The pork and
poultry surveys will be published this year.
32
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Through a cooperative agreement with
NCEA, scientists at the State University of
New York in Binghamton studied the levels
of dioxins present in cooked meat and fish
products. Results of this study also were
presented at the 16th International Confer-
ence on Dioxin and Related Compounds.
In a joint effort with the Department of En-
ergy, NCEA scientists evaluated the chro-
nology of the occurrence and levels of
dioxins resulting from atmospheric deposi-
tion into lake sediments over the past cen-
tury. Samples from 11 lakes throughout the
continental U.S. and Alaska were evalu-
ated. This provided the most convincing
evidence to date regarding time-trends of
dioxin-like compounds in the U.S. environ-
ment. The results of this study have been
incorporated into the dioxin reassessment
update.
Integrated Risk Information System
Provides Consistent Risk Estimates
Consistent, high quality information on hu-
man health risk is needed by EPA program
offices, regional risk assessors, and local
policy-makers. The Integrated Risk Infor-
mation System (IRIS) provides summaries
of EPA-consensus information on health ef-
fects needed for risk assessments and other
health evaluations in an easy-to-access, un-
derstandable form. IRIS unifies EPA assess-
ments, ensuring consistent risk estimates
for the same chemical across EPA pro-
grams. Since its release to the public in
1988, IRIS information on more than 500
chemicals has been used extensively by
state and local governments, industries,
and environmental action groups. The da-
tabase and the process for developing the
agency-wide consensus are managed and
maintained by NCEA's Washington and
Cincinnati offices. IRIS is available on the
Internet, through the National Library of
Medicine's TOXNET system, and distrib-
uted worldwide in cooperation with the
STAR Grants for Integrated Risk
Information
The University of California at
Berkley is developing a
physiologically based model that will
provide a method to predict effects
at the population level that accounts
for human variability.
The University of Rochester Medical
Center is investigating the role of
toxic chemicals to the nervous
system and a possible relation to
autism. This research looks at
potential non-cancer effects as yet
not characterized.
Harvard University is developing
statistical methods for non-cancer
risk assessment that will allow the
utilization of distributions of
exposure and toxicity data rather
than point estimates that often
extensively under- or over-predict
risk.
World Health Organization and the Pan
American Health Organization.
In early FY96, ORD initiated a pilot program
to test improvements in the process for devel-
oping IRIS's consensus health information,
improving external peer review, and enabling
public input to the information collection pro-
cess. The pilot will be completed in 1997, at
which time an analysis of the pilot will help
to define the best ways to improve IRIS.
Research Program Studies Pesticide
Exposure and Effects for Children
ORD's research to protect children from the
adverse health effects of pesticides has been
influenced strongly by the 1993 National
Academy of Sciences report, Pesticides in the
Diets of Infants and Children. The Academy
concluded that both exposure and health
effects experienced by children are different
from those of adults and that the federal
government should do more to address their
unique risks.
33
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Children's exposures to pollutants
and the potential health effects
differ from those of adults. As part
of an EPA initiative, ORD scientists
research the factors that make
children more vulnerable than
adults to health effects from
pollutants, (photo: Steve Delaney)
The major objectives of the research pro-
gram are to advance understanding of fac-
tors that make children more vulnerable to
health effects of pollutants than adults and
to develop methods and guidance for as-
sessing risks to children so that we can ap-
ply new-found understanding to reduce
risks to children.
ORD's research program includes a multi-
disciplinary evaluation of age-related differ-
ences in sensitivity to pesticides. Studies are
underway using laboratory animals to ex-
amine differences in the way pesticides are
distributed and detoxified in the body
among different age groups.
ORD also is studying the effects of pesticide
exposure at critical stages of development,
including prenatal and infancy, in labora-
tory animals. Special emphasis is being
placed on evaluating effects on the develop-
ing nervous, immune, and reproductive
systems. Research is focusing on the evalua-
tion of effects that might be expected to oc-
cur in humans, including subtle effects such
as deficits in learning and memory. Finally,
the program is evaluating better ways to use
the data collected in animal studies to pre-
dict health outcomes in humans.
In addition to looking at health effects,
NERL scientists are studying how children
are exposed to pesticides. By understanding
which pathways of exposure are of greatest
concern, it is possible to better focus preven-
tive measures. This research is in support of
EPA's Office of Prevention, Pesticides, and
Toxic Substances to revise the Post-Applica-
tion Exposure Monitoring and Assessment
Guidelines for Pesticides and Consumer Use
Products in Residential Environments.
An important element of pesticide exposure
research is an intensive study of how resi-
dues of pesticides are transported into and
34
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around homes and the behaviors of children
(such as crawling on the floor) that bring
them into contact with these residues. For ex-
ample, methods for detecting loose residues
on carpets, bare floors, and lawns are being
evaluated and field tested under controlled
conditions. Round-robin performance tests
have been completed with the assistance of
pesticide manufacturers. New and improved
methods for determining dermal exposure to
pesticides have been developed including
more precise procedures for gathering
samples from hands and surfaces. This re-
search has produced three draft protocols for
EPA's Office of Pesticide Programs to use in
issuing guidance on measuring dislodgeable
pesticides. The goals of this research are to
predict children's exposure and risks to pesti-
cides used in and around homes, and to de-
velop strategies for reducing risks to children.
Besides research underway in our own labs,
NCERQA has recently awarded a special set
of competitive research grants to universities
in the area of children's exposure to pesticides.
STAR Grants for Pesticides
Arizona State University is currently
measuring environmental
concentrations of pesticides in and
around the homes of 300 children in
Yuma County, Arizona to evaluate
multiple sources of exposure and
their relative contributions.
Mississippi State University is
assessing levels of pesticide that
are transferred from dogs to
children after flea control
treatments.
The University of Washington is
investigating the exposure of groups
of urban, suburban, and rural
children to pesticides. The data will
be used to determine the relative
contribution of the various pesticide
sources and to develop models for
predicting pesticide exposure.
Finally, in collaboration with the National
Cancer Institute and the National Institute of
Environmental Health Sciences, ORD is con-
ducting the Agriculture Health Study, a long-
term study of 75,000 subjects—primarily
farmers—to examine pesticide exposure and
health risks. EPA will measure exposure of a
subset of 250 farmers, plus 50 spouses and 50
children, during periods of pesticide applica-
tion. The study is expected to advance our
understanding of the health risks experi-
enced by farm families.
Agency Guidelines for Assessing
Reproductive Toxicity Finalized
In October 1996, the Agency published the
final Guidelines for Reproductive Toxicity Risk
Assessment (EPA 630-R-96-009). These guide-
lines, the result of a cross-agency effort
guided by the Risk Assessment Forum, will
promote consistency in the Agency's assess-
ment of toxic effects on the male and female
reproductive systems.
The guidelines discuss the scientific basis
for concern about exposure to agents that
cause reproductive toxicity and describe the
principles and procedures for conducting
risk assessments for reproductive toxicity.
They identify and discuss the use of default
assumptions, present summaries of the stan-
dardized testing protocols used to generate
information on reproductive toxicity, discuss
the various types of information that may be
encountered in evaluations of reproductive
toxicity, and specify the approaches that are
appropriate for quantitative risk assessment
and exposure assessment. These guidelines
complement the Agency Guidelines for Devel-
opmental Toxicity Risk Assessment.
ORD's Health Monitoring Experience
Impacts U.S./Mexico Border Project
The U.S./Mexico Border Project is a good
example of how ORD's unique expertise in
environmental health research is contribut-
ing essential information needed for solving
35
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On a rooftop in Brownsville,
Texas, scientists collect and
measure fine and course
particles, acidic gases, and
volatile and semi-voltatile organic
compounds. The project is one of
many research efforts of Border
XXI, a multi-agency, international
effort to increase and improve the
data needed to set priorities for
environmental protection efforts in
the region.
a serious local health problem. The project
also is a model for interagency cooperation in
which stakeholders have been able to explain
their needs, and the federal and state govern-
ment organizations involved have not dupli-
cated one another's efforts or resources to
respond to those needs.
ORD has been a driving force in the Inter-
agency Coordinating Committee (ICC) for
U.S./Mexico Border Environmental Health, a
coalition of eight organizations from the De-
partment of Health and Human Services, the
states of Texas, Arizona, New Mexico, and
California, Mexico's Ministry of Health, and
the Pan American Health Organization.
In 1992, ORD researchers, in an effort led by
NHEERL and NERL, collected exposure data
in the Lower Rio Grande Valley as part of the
ICC response to reports from the Centers for
Disease Control and Prevention (CDCP) of
clusters of anencephaly in the Lower Rio
Grande Valley. These data showed high lev-
els of polychlorinated biphenyls (PCBs) con-
tamination in fish. Based on the findings
from the first phase of ORD's monitoring
pilot study, the State of Texas and CDCP rein-
forced fishing bans and advisories and pro-
vided information to the public on how to
keep water bottles from being contaminated.
Since the initial studies, it became clear to the
ICC member organizations that there was a
dearth of exposure data needed to set priori-
ties and determine the best courses of action.
Through an open process involving the pub-
lic and stakeholders, priorities were set for
further research that built on the information
existing with the federal and state agencies
and utilized their unique areas of expertise to
fill data gaps. Currently, ORD has the lead, is
collaborating, or is supporting research in
three main areas: surveillance and monitor-
ing; exposure and epidemiology; and com-
munications, training, and education.
New Framework Developed for
Assessing Dose-Response for PCB
Mixtures
Scientists with the Washington, DC office of
NCEA developed a new cancer dose re-
sponse assessment for environmental
36
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mixtures of PCBs. Prior assessments had
been based on previously available informa-
tion that did not allow differentiation
among environmental mixtures. However,
new data indicated that the "how" of expo-
sure (or pathway) was an important factor
in assessment. For example, the PCBs that
bioaccumulate in fish are generally of
greater concern than the PCBs that would
be dissolved in drinking water. To make
these judgments, the new assessment con-
siders the processes that chemically change
PCB mixtures after they are released into
the environment. ORD's report provides
guidance on how to apply a range of dose-
response parameters to different exposure
routes, partial lifetime exposure, and differ-
ent mixtures of PCBs. In addition, ORD is
assisting the program offices with incorpo-
rating these results in the guidance they de-
velop for analyzing samples of PCBs.
Superfund Technical Support Center
Provides Toxicity for Superfund
Cleanups
The Superfund Technical Support Center of
NCEA in Cincinnati, Ohio, is the focal point
for the assessment of toxicity information
and the development of provisional toxicity
values for chemicals commonly found at
Superfund sites.
During FY95-96, the center responded to a
total of 326 requests: 163 for specific Super-
fund sites and 163 from EPA regional offices.
The center developed provisional risk as-
sessments for 98 new chemicals and revised
existing risk assessments for 33 chemicals.
The Superfund Technical Support Center is
an important information resource that en-
ables ORD to reach out to communities by
providing a central location for credible
evaluations of toxicity information.
NHEXAS—Monitoring to Improve
The National Human Exposure Assessment
Survey (NHEXAS) seeks to better under-
stand the complete picture of human expo-
sure to toxic chemicals, by looking at vari-
ous exposures to important toxic chemicals
through all routes of exposure. ORD scien-
tists developed the concept and design of
the survey, and coordinated its implementa-
tion with the Food and Drug Administra-
tion and the National Institute of Standards
and Technology. ORD scientists from NERL
and NCEA serve along with scientists from
other participating agencies on each of the
study teams.
With NHEXAS data, scientists will have a
baseline description of the normal range of
human exposure to environmental chemi-
cals that should improve estimates of total
human exposure. The data will help iden-
tify groups of people who are more exposed
or particularly sensitive to environmental
chemicals, allow comparisons with studies
of particular exposure routes, relate pollu-
tion sources to actual exposures, and allow
comparisons of actual exposures to expo-
sures predicted by models.
NIIEXAS studies are being conducted in
three different regions of the U.S. with other
research organizations:
* Arizona—with the University of
Arizona, Battelle Memorial Institute, and
the Illinois Institute of Technology7.
« Midwest states of Illinois, Indiana,
Michigan, Minnesota, Ohio, and
Wisconsin—with the Research Triangle
Institute and the Environmental and
Occupational Health Sciences Institute of
Rutgers University.
• Maryland—with Harvard University,
Emory University, Johns Hopkins
University, and Westat, a survey
consulting firm.
Sampling began in FY95 and the laboratory
analysis is expected to be finished by early
1998. Data from the studies are expected to
be available for use in 1999.
37
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The spirometer, a standard
instrument that measures
pulmonary function in medical
patients, is used also by ORD's
Human Studies Division of
NHEERL to measure lung
changes from exposure to
environmental pollutants. At
ORD's world class facility for
human studies, the subject
forcefully exhales into the tube
and the spirometer measures the
quality of breath exhaled and its
rate of flow.
Study Investigates Education and
Cleanup to Reduce Lead Exposures
in the Home
Nine percent of children six years old and
younger in the U.S. have lead in their blood
in amounts greater than the level believed to
cause adverse effects to the neurological sys-
tem. Public health measures to address this
problem are hindered by a lack of practical
and cost effective methods to prevent expo-
sures.
During 1996, scientists from NERL and the
University of Medicine and Dentistry of the
New Jersey Robert Wood Johnson Medical
School collaborated on the Childhood Lead
Exposure and Reduction Study (CLEARS).
The study conducted in Jersey City, New
Jersey, tested the effectiveness of a two part
intervention in reducing the levels of lead
found in children's blood.
The study compared two intervention ap-
proaches: education and biweekly cleaning
by professionals trained in methods to con-
trol lead contaminated dust. Study partici-
pants were divided into two groups. One
group received routine information about
lead and served as the control group. The
second group received training and had
their houses cleaned every two weeks. Dur-
ing the course of a one-year intervention, the
treatment group was offered biweekly assis-
tance with house dust control and a series of
educational sessions about lead. The partici-
pants were followed over one to two years
with measurements taken of blood lead lev-
els and the levels of lead contamination in
the participants' homes. After intervention,
blood lead level fell by 17 percent in the
treatment group and increased in the control
group. The mean difference between the
groups in final blood lead was most striking
in the summer months. The reduction of
blood lead in the treatment group was
greater for the children whose houses were
cleaned nine times compared to those in
homes cleaned on fewer occasions.
The study demonstrated that biweekly
cleaning and education is a better approach
for reducing children's blood levels and
household lead exposure for children than
education alone. These results confirm the
importance of controlling dust and provid-
ing education as a practical strategy for chil-
dren at risk of lead exposure.
Report Integrates Lead Studies of
Three Cities
In April 1996, NCEA in Research Triangle
Park, North Carolina, completed a report
that integrates findings from three studies of
whether abatement of lead in soil reduces
the levels of lead in blood of inner city chil-
dren. The project, known as the "Three
Cities Lead Study," was authorized in 1986
under the Superfund Amendments and
Reauthorization Act, and begun in December
1986, in cooperation with state health
departments and local scientists.
38
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Major Factors In
Health Risk Assessment
Environmental
Levels
i *
1
Applied
i a
1
Delivered Dose
(target)
I 4
Health
Effects
i
~t~
Risk Assessment
Major Research Components
_ FvrvLQijrn Aosfi*Mirnftnft
tJ^AUHdlO rtsKSOJKHH lv?l 11
Physiologically Based
Pharmacokinetic Models
Biologically Based
Dose-Response Models
.2
£
D
The integrated report confirms the findings
of the individual studies and reaches the fol-
lowing conclusions:
• When soil is a significant source of lead
in the child's environment, the
abatement of that soil will result in a
reduction in exposure that will, under
certain conditions, cause a reduction in
childhood blood lead concentrations.
• Although these conditions for a reduction
in blood lead levels are not fully under-
stood, it is likely that four factors are
important: 1) the past history of exposure
of the child to lead, as reflected in the
pre-abatement blood lead levels; 2) the
magnitude of the reduction in soil lead
concentrations; 3) the magnitude of the
other sources of lead exposure, relative to
soil; and 4) a direct exposure pathway
between soil and the child.
PB-PK and BBDR Modeling
In risk assessments, scientists draw conclu-
sions about how a chemical will effect
people from data gathered in studies of ani-
mals given large doses of the chemical.
These conclusions, or extrapolations, are
necessarily limited because the studies from
which the conclusions are drawn do not
mimic real exposures to real people. Ex-
trapolations can be made from high to low
doses, from laboratory animals to people, or
from one route of exposure for which there
are data to another route of exposure for
which there are none. There are many un-
knowns connected with these extrapola-
tions. Research to fill in the data gaps is
necessary to improve risk assessments that
use extrapolations.
Since 1988, ORD has been conducting studies
to develop and improve the models used for
extrapolations in risk assessments. Two such
models are the physiologically based phar-
macokinetic (PB-PK) model and the biologi-
cally based dose-response (BBDR) model.
In FY95, scientists with NHEERL studied the
difference in dose of ozone to humans and
animals and how those differences can
Physiologically Based
Pharmacokinetic (PB-PK) models
are mathematical descriptions of
how pollutants are absorbed,
distributed, metabolized, and
eliminated in animals and humans.
Improving PB-PK models reduces
uncertanity associated with
estimating the applied dose for a
risk assessment. Biologically
Based Dose-Response (BBDR)
models describe the biological
cascade of events from exposure
to a pollutant to onset of disease.
Improving BBDR models reduces
uncertanity associated with
estimating a delivered dose for a
risk assessment.
39
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impact a risk assessment. The study
demonstrated that humans received four
times the dose to lung tissue at a given
environmental level than did rats, largely
due to differences in exercise levels and the
associated breathing rates. The study also
provided information on pulmonary dose
levels that can be used for assessing similar
gases for which there is no data. The results
demonstrated the importance of factoring
in human exercise and breathing patterns
when extrapolating from laboratory
animals to humans.
To understand and predict the mechanism
of toxicity scientists at NHEERL study the
cascade of events that occur from exposure
to a chemical to disease. Better understand-
ing of these mechanisms improves the
dose-response estimates used in risk
assessments. ORD scientists are studying
persistent substances, such as dioxin, to
develop models of how toxicity occurs.
Other ongoing studies of mechanisms of
toxicity and repair include research on the
hazardous air pollutant phosgene and the
fungicide vinclozolin.
40
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POLLUTION PREVENTION AND NEW
TECHNOLOGY FOR ENVIRONMENTAL
PROTECTION
Research into preventing
pollution is an important aspect
of ORD's research program.
ORD also conducts research
and demonstration of new
technology, such as
bioremediation methods for
cleaning up oil spills.
Pollution prevention works
as a powerful risk
management tool because it
is far more cost-effective
and protective of the
environment than waiting to
solve environmental
problems after they have
been created. Pollution
prevention, supported by
objective scientific and
technical data, reduces or
eliminates the need for legal
actions and regulatory
standards, which can be
costly and difficult to
implement. It also offers an
opportunity for meaningful
stakeholder input and
participation as part of the risk management research and development
process.
ORD's intramural and extramural research programs support cutting-edge
research and development of new tools, techniques, and processes for
preventing and cleaning up pollution. EPA's Small Business Innovation
Research Program accesses and nurtures the expertise of private innovators
for pollution prevention and other environmental technologies. The
accelerating development of new environmental technologies has created
growing opportunities for managing environmental threats to public health
and natural resources, as well as economic opportunities in the U.S. and
abroad.
41
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Scientists estimate that over
4,000 megawatts of electric power
could be generated from 7,480
existing and closed landfills.
Pollution Prevention Software Helps
Industry Evaluate Impacts of
Processes on the Environment
In 1995, a software program, Pollution Pre-
vention Progress (P2P), was developed by
the Sustainable Technology Division of
NRMRL to assess how pollution can be pre-
vented or decreased as a result of product
redesign, reformulation, or replacement in
industrial practices. The program tracks the
environmental media affected and three cat-
egories of pollution impacts (human health,
environmental use impairment, and dis-
posal capacity). It also provides information
about the specific classes of pollution pre-
vented (e.g., toxic organics, aquatic life toxi-
cants, hazardous wastes). In 1996, a second
version of the program was developed that
has recently undergone beta testing by a
number of users both in and outside of the
Agency. The revised version of the software
will be released to the public in 1997. This
version, which will incorporate a database
of almost 3,000 pollutants, will process un-
certainties associated with incompletely
classified pollutants and provide reports of
regulatory impacts.
U.S. Navy to Save Millions with ORD
CFC Replacement
Many Navy shipboard chillers currently use
the refrigerant CFC-114, an ozone-depleting
compound. As part of its program for finding
replacements for ozone depleting substances,
scientists with the Air Pollution and Control
Division of NRMRL in Research Triangle
Park, North Carolina, have identified an ac-
ceptable replacement for the Navy's refriger-
ant. A chemical of the family of hydro-
fluorocarbon (HFC) 236 was selected based
on synthesis, evaluation of properties, com-
puter modeling, application testing, and
safety testing conducted by ORD. Retrofitting
shipboard chillers to HFC-236fa is estimated
to save the Navy between $300 million and
$500 million (depending on the number of
ships converted) compared to having to com-
pletely replace the chillers. HFC-236fa has no
ozone depletion potential.
Landfill Gas
Low BTU-fuel
Heavily contaminated
Gas Wells and
Collection System
Energy Conservation
Energy wheeled to another
municipal facility
Energy sold offsite
Utility
Power
Lines
Contaminant Removal
AC Power
to Grid
Remove sulfur and halides
PC25
Fuel Cell
Power Plant
42
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Fuel Cell Developed That Uses
Landfill "Waste" Gas to Make
Electricity
Scientists with NRMRL's Air Pollution Pre-
vention and Control Division have devel-
oped an innovative filter that purifies the
gaseous mixture that comes from landfills
into pure methane. The methane can then be
used in fuel cells that generate electricity.
In a recent test conducted at a California
landfill, the filter removed more than 30
contaminants with 99.95 percent efficiency.
An environmental assessment has shown
that the fuel cell / gas cleanup technology
can eliminate virtually all fugitive meth-
ane, non-methane organic compounds, and
toxic emissions.
Scientists estimate that over 4,000 mega-
watts of electric power could be generated
from 7,480 existing and closed landfills. Fuel
cells, utilizing just 25 percent of landfill gas,
could provide power to over 5 million
homes. Testing of the technology continues
at a Groton, Connecticut, landfill in partner-
ship with International Fuel Cells Corpora-
tion, who developed the fuel cell, and
Northeast Utilities, who is funding the test.
The technology placed second in the Envi-
ronment Category of Discover Magazine's
1996 Seventh Annual Technology Awards.
Pollution Prevention Approaches
Applied to Indoor Air Quality
Since most people spend as much as 90
percent of their time indoors and indoor
pollutant concentrations frequently exceed
those outdoors, indoor air quality can pose
an important environmental health risk. At
the Air Pollution Prevention and Control
Division of NRMRL in Research Triangle
Park, North Carolina, researchers are ap-
plying the principles of pollution preven-
tion in three different projects to improve
indoor air quality. In one study, researchers
are developing a standard test method that
will assist manufacturers in characterizing
emissions from office equipment and exam-
ining how these emissions might be re-
duced. Research also is underway to
develop an innovative spray nozzle that will
allow manufacturers to reformulate certain
aerosol consumer products using air and
water in place of volatile organic com-
pounds and hydrocarbons, without compro-
mising acceptable product characteristics.
Third, ORD scientists are evaluating emis-
sions from engineered wood products. This
project is targeted at identifying the primary
sources of emissions from these products
and evaluating lower-emitting alternatives.
STAR Grants on Pollution Prevention
Applied to Indoor Air Quality
Several research projects at the
University of Iowa and the Georgia
Institute of Technology focus on
finding non-toxic substitutes for
organic solvents used in chemical
reactions.
Oklahoma State University is
developing a process for producing
cutting tools with a coating that will
eliminate the need for traditional
oils and solvents in dry machining.
Michigan Technological University
is developing a model based on
Markovian decisionmaking that will
enhance industry's ability to conduct
life-cycle assessments of a
production process to identify
targets for reducing pollution. The
model will be evaluated in the
automobile manufacturing industry.
Life Cycle Assessment Book
Published
The principles of environmental life cycle
analysis are described in a book recently ed-
ited and coauthored by a researcher in
NRMRL's Sustainable Technology Division.
43
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One of the SITE projects
demonstrated is the base-
catalyzed decomposition (BCD)
process developed by ORD for
treating soils, sediments, and
sludges contaminated with
chlorinated compounds. At this
demonstration conducted at the
Koppers Company Superfund site
in Morrisville, North Carolina, the
process removed 99 percent of
pentachlorpphenol and 92 percent
of the dioxins and furans.
(photo: Terry Lyons)
The book, Environmental Life Cycle Assess-
ment, was developed for readers who want
to learn more about how the concept is be-
ing applied in various industries for prod-
uct and process design and improvement,
as well as in public policy development.
Numerous examples from practitioners in
North America and Europe are included.
Environmental Technology
Verification Program
Throughout its history, EPA has evaluated
technologies to determine their effectiveness
in preventing, controlling, and cleaning up
pollution. EPA is now expanding these ef-
forts through the Environmental Technol-
ogy Verification Program (ETV) /. Initiated
in late 1995 and coordinated by NRMRL's
Washington office, ETV accelerates the com-
mercialization of new technologies into the
domestic and international marketplaces by
using the facilities and expertise of partner
"verification organizations" to carry out
technology evaluations and, through these
evaluations, to verify the performance of
commercial-ready innovative technologies.
In 1996, six pilot evaluations were initiated
to evaluate drinking water systems, site char-
acterization and monitoring devices, indoor
air products, pollution prevention, treatment
technologies, and an independent project that
is not confined to any single technology area.
In addition, five new pilot projects on
pollution prevention were added.
SITE Program Builds on Past
Success to Set New Direction
Through the Superfund Innovative Technol-
ogy Evaluation (SITE) program, coordinated
by NRMRL, EPA has developed, evaluated,
and demonstrated a wide variety of innova-
tive technologies that have reduced the un-
certainty and costs associated with cleaning
up hazardous waste sites. The program has
completed 84 field demonstrations of reme-
diation technologies and 29 demonstrations
44
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of contaminant measuring and monitoring
approaches. Today, due in large part to the
success of the SITE program, more than half
the technologies selected by EPA for site
cleanups are innovative technologies not
commonly used ten years ago. In a spot
sampling of 17 cleanup decisions using SITE
technologies, projected savings averaged
$12 million a site, with total projected
savings, normalized to 1986 levels, of over
$213 million for the 17 sites.
Building on the accomplishments of the
past ten years, SITE is working with the
remediation community to identify priority
sites and the technology suppliers to match
the sites with the technology solutions.
SITE is combining efforts with other EPA
offices and other agencies such as the
states, the Department of Defense and the
Department of Energy. The program fo-
cuses on low-cost, easily implemented, and
highly effective technologies to solve haz-
ardous waste problems; and develops cred-
ible quality assurance guidelines for testing
those technologies.
SBIR Program: Small Business
Innovations Solve Big Environmental
Problems
Created in 1982 by the Small Business Inno-
vation Act, EPA's Small Business Innovation
Research (SBIR) Program is an important
part of the Agency's research and develop-
ment efforts. Through the program, managed
by NCERQA, EPA makes awards to small,
high-technology firms for research and de-
velopment of cutting-edge technologies.
Over the past decade, dozens of innovative
technologies have emerged from this pro-
gram. A number have moved quickly from
"proof of concept" to commercialization. In
other cases, companies are still seeking the
start-up capital or other support needed to
achieve commercialization of their technolo-
gies. A comprehensive discussion of the pro-
gram and its success stories can be found in
EPA's Small Business Innovation Research
(SBIR) Program: Innovative Solutions for Envi-
ronmental Problems, December 1996. The fol-
lowing two success stories give a sense of
how the SBIR program works.
The Autosorf technology is set in
motion three-fourths of the way
through the sorting process.
Further sorting of plastic
containers into five categories
removes the highly toxic PVC
plastics before incineration. The
remaining plastics can be used to
produce many other products from
carpet to clothing.
FILM PLASTIC
EIPAC™ ALUMINUM PULSORT™ EDDY
CONCENTRATOR CURRENT SEPARATOR
BALEFIILL MATERIAI
1: RESIDUAL BAG OPENING
2: FERROUS RECOVERY
3: GLASS/GRIT HUMUS RECOVERY
GLASS: Clear
Green, Brown
FERROUS COMPOST- GLASS
MATERIAL ABLES AGGREGATE
45
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Example of a Bioremediation Process
Microorganisms eat oil
or other organic
contaminant
Microorganisms digest oil and
convert it to carbon dioxide (CO2)
and water (H2O)
Microoganisms
give off CO2 and
H20
National Recovery Technologies (NRT)
was awarded an SBIR contract in 1988 to
develop technology that uses an electromag-
netic sensor to separate the different types of
plastics found in recycling facilities. The re-
sulting technology, AutoSort® and
VinylCycle®, assists in recycling different
types of plastic bottles by sorting them ac-
cording to their chemical makeup. PVC
plastics, which are highly toxic when
burned, are removed before incineration.
The remaining plastics can then be used in
the production of many products—from car-
pet to clothing.
By 1996, over 40 VinylCycle® systems were
in operation in the U.S., Europe, Japan, and
Australia. The success of the technology has
fostered development of a color/polymer
sorter for plastics, Multisort®, which sorts
5,000 pounds of plastic bottles per hour by
color and type. In recognition of its accom-
plishments, NRT became one of the first
companies to receive the Tibbetts Award in
1996.
Membrane Technology and Research, Inc.
(MTR) received an SBIR contract to develop a
membrane separation process for recovering
VOCs from contaminated air streams. VOCs
are the most common pollutants emitted
from chemical manufacturing processes. The
Clean Air Act requires that these emissions
be eliminated or reduced. Each year, chemi-
cal manufacturers must remove some 500
million pounds of organic pollutants from 50
million cubic feet of air.
The system, VaporSep®, combines proven
condensation techniques with a unique
pressure-driven membrane vapor separation
process. The combination produces far better
recovery performance than condensation
alone, achieving much higher recovery rates
or maintaining existing recovery rates under
less extreme temperature and pressure con-
ditions. MTR has reported sales of $4.4 mil-
lion and has installed more than 30 systems
in chemical and pharmaceutical plants.
Bioremediation Research Promotes
"Natural" Cleanup Technologies
Bioremediation harnesses nature's most
efficient recycling agents—microorganisms—
to reclaim contaminated environments.
Because it relies on natural processes,
bioremediation is far less expensive and
46
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far less disruptive to the environment than
conventional remediation. ORD launched a
research program in 1987 to discover and
develop bioremediation technologies as the
U.S. was beginning the costly cleanup of
thousands of sites contaminated by
uncontrolled waste disposal, leaking under-
ground storage tanks, and other sources.
The following is a small sample of the
technologies developed and tested under
the bioremediation program managed by
NRMRL.
Scientists with NRMRL and the U.S. Depart-
ment of Agriculture have been awarded a
patent for their research using fungi to de-
grade lignin, a naturally occurring polymer
that is chemically related to pollutants that
resist biodegradation. Fungi, unlike bacteria,
can move through soil. The process is appli-
cable to a wide range of organic pollutants
such as aromatic hydrocarbons and muni-
tions chemicals. New methods for the
introduction of the fungi into the soil also
have been developed to improve the cost
effectiveness of the treatment.
One obstacle to successful bioremediation
of deep soils is lack of oxygen needed by
microorganisms. ORD scientists pioneered
bioventing, a method of delivering enough
oxygen to allow successful in situ bioreme-
diation of deep soils. Bioventing costs about
20 times less than the traditional excavate-
and-incinerate approach. In FY95, after
several years of experience field testing the
process, NRMRL combined efforts with the
U.S. Air Force to compile a how-to manual,
Principles and Practices Manual for Bioventing.
The manual details the basic science behind
the process and gives guidance on how to
implement bioventing. The manual has be-
come an essential reference for EPA remedial
project managers (RPMs), state Under-
ground Storage Tank program managers,
and environmental engineering firms.
Monitoring Indicators Developed to
of Using
Bioremediation to Clean Up
Subsurface Contamination
Contamination of soil and ground water
from fuel hydrocarbons at Department of
Defense facilities is a common problem due
to heavy use and maintenance of military
vehicles and aircraft. Under the sponsorship
of the Strategic Environmental Research
and Development Program, scientists at the
Subsurface Remediation Division of
NRMRL in Ada, Oklahoma, have devel-
oped monitoring indicators to identify the
major inorganic and organic parameters
that serve as yardsticks for subsurface
bioremediation of fuels. This monitoring ca-
pability will result in substantial cost saving
over traditional remediation monitoring ac-
tivities. Conservative estimates predict a 20-
25 percent savings in long-term monitoring
costs.
The appropriateness of natural attenuation
as an acceptable cleanup method must be
evaluated on a site-by-site basis. In addition
to monitoring for the contaminants found in
the source, reliable indicators of the
progress of the bioremediation process are
needed.
The monitoring indicators are being vali-
dated at Wurtsmith Air Force Base.
47
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48
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WORLD WIDE WEB SITES
EPA's Office of Research and Development
http://www.epa.gov/ORD/
http://www.epa.gov/ORD/publications/
http: / / www.epa.go v / ORD / whatsnew.htm
ORD's National Center for Environmental Research and Quality Assurance
http: / /www.epa.gov/ncerqa/
Environmental Research Centers
http: / / es.inel.gov / ncerqa / centers /
Endocrine Disrupter Working Group of the Committee on the Environment and Natural Resources
http: / / www.cpa.gov/cndocrinc/framctcxt.html
Special Report on Environmental Endocrine Disruption: An Effects Assessment and Analysis
http://www.epa.gov/ORD/WebPubs/endocrine/
Deformed Frogs Workshop in September 1996
http://ww\v.im.nbs.gov/naamp3/papers/59df.html
Deformed Frog Pictures
http: / / mncs .kl 2 .mn.us / frog/ picts .html
Environmental Monitoring and Assessment Program (EMAP)
http: / / www.cpa.gov/cmap/
Multi-Resolution Land Characteristic Consortium.
http://www.epa.gov/mrlc/
Interagency Coordinating Committee for U.S./Mexico Border Environmental Health
http:// wwiv.epa.gov/orsearth/
Environmental Technology Verification Program (ETV)
http: / / www.epa.gov / etv /
SITE Program
http://www.epa.gov/ORD/SITE/
To order hard copies of ORD publications call (513) 569-7562.
While there would be no research accomplishments to report without the hard work of ORD scientists and
engineers, the following people contributed their time and talent to produce this report:
Carol Grove, Pat Burke, and Steve Wilson of the National Risk Management Research Laboratory;
Bob Dyer, Fred Hauchman, and Steve Jackson of the National Health and Environmental Effects
Research Laboratory; Johnnie Pearson of the National Exposure Research Laboratory; Linda Tuxen
and Judy Theisen of the National Center for Environmental Assessment; Ron Slotkin of the National
Center for Environmental Research and Quality Assurance; Scott Schwenk of the Assistant
Administrator's Office; and Mary Wigginton of the Office of Science Policy.
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