United States
Environmental Protection
Agency
EPA/600/F-99/006
March 2000
http://www.epa.gov/NERL
Research and Development (MD-75)

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 Who Are We?
 The National Exposure Research Laboratory (NERL) is one of three
 national laboratories that conduct research for EPA's Office of
 Research and Development. NERL headquarters and two of its
 research Divisions are located in Research Triangle Park, NC. Other
 research Divisions are located in Athens, GA, Cincinnati, OH, and
 Las Vegas, NV. NERL conducts research and development that leads
.to improved methods, measurements and models to assess and predict
 exposures of humans and ecosystems to harmful pollutants and other
 conditions in air, water, soil, and food.
 What is Environmental Exposure?
 Exposure is the contact of people (or other organisms) with an
 environmental stressor for a specific duration of time. Stressors can
 include chemical pollutants, physical agents such as UV-B radiation,
 or other processes such as alteration of wildlife habitat. Assessing
 environmental exposure involves:
 9   Characterizing sources of pollution, including point sources such
    as industrial plants; mobile sources such as automobiles; and
    non-point sources such as agricultural and land-management
    practices.
 0   Understanding the processes that control the transport,
    transformation, and fate of these stressors as they travel from
    sources, through multiple media (air, water, food, and soil), to
    "receptors" (humans, plants, and animals that may be affected by
    them, dkectly or indirectly).
 0   Characterizing exposures of humans and ecosystems, which can
    involve measuring  stressors in various media and making
    measurements on receptors that provide evidence that they have
    been exposed ("exposure indicators"). Examples range from
    biomarkers in individuals and organisms to measures of
    community composition in ecosystems.

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  °   Describing how micro-environments (e.g., the interior of an
     automobile or subsurface sediments in a lake) and behavior
     patterns of people and animals affect their exposure. Exposure
     assessment also may involve quantifying the relative importance
     of different pathways of exposure to a particular pollutant.

  Why is Environmental Exposure Important?
  In carrying out its mission to protect the environment, EPA must
  understand the risks posed by pollutants and other stressors.
  Exposure assessment is one critical input used by EPA and others to  '
  assess risks. Chemicals that are quite toxic may pose little actual risk
  if exposures are low; conversely, relatively nontoxic stressors may
  pose substantial risks if people or wildlife are highly exposed. As a
  result, understanding exposure is essential in assessing the risks that
  may arise from current or new tecTmoldgiesTp'bWie^lnd'regulatibnsf
  and even increased growth in populations, energy use, and the
  economy.  Exposure measurements, methods, and models also are
  important hi tracMng compliance with environmental regulations and
  achieving environmental goals.       „		
. How Does NERL Conduct Research?
 The Laboratory has an in-house workforce of several hundred
 scientists, engineers, and other permanent federal employees. A
 group of these employees work for the National Oceanographic and
 Atmospheric Administration under a permanent agreement with EPA.
 NERL also provides temporary training opportunities for
 undergraduate and graduate students and post-doctoral trainees, and
 sponsors senior citizens through the Senior Environmental
 Employment (SEE) Program.
 A significant portion of NERL's research is conducted in
 collaboration with the other Laboratories and Centers of ORD whose
 missions are health and ecological effects research, risk assessment,
 and risk management. This linkage allows ORD to achieve its overall
 mission of understanding environmental problems and developing

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 tools and technologies to prevent or reduce them. Other NERL
 projects rely on extensive external collaboration with entities such as
                                  utmties' ****** and
Research approaches NERL uses to improve risk assessment include

^TmS PabaUm S°UrCeS; deVel°ping en™°«al fate and
transport computer models that can be used to quantify how risk
management options are likely to affect exposures; developin- and
enhancing measurement methods for pollutants and exposure
ndicators; and developing exposure models that reflect individual
>enaviors and microenvironments.
'ihatare We Working on Now?
ie foUowing are examples of some of our current research priorities

Sri1*6 ^Tr " H°W C3n ** concenta*ions ^d composition of
borne particles associated with severe health problems be
.asured and predicted, and are there differences in exposures among
         rai8 (e-g" people suffering from diseases
posure of Children to Pesticides : Are children likely to experience
^ater exposure to pesticides and other chemicals because of th"ir
laviors and the environments in which they spend time?

hogens and Disinfection By-products in Drinking Water - How
i we best measure the microbial and chemical contaminants of
ifang water, and to what extent are people exposed to pathogens in
iking water and at beaches?                     « JJ«"iio&ens rn

                                         - How ca" we best
 h    f                       'g" f°°d'    water'  and-to
ith contact) by wmch people are exposed to harmful pollutants'?
important current NERL project contributing to this £ea is    '
ional Human Exposure Assessment Survey (NHEXAS).

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 Landscape Sciences - What do patterns of land use and human
 development tell us about the vulnerability of ecosystems? Work in
 this area is part of ORD's Environmental Monitoring and Assessment
 Program (EMAP).

 Multimedia Integrated Modeling System - How can we use
 supercomputers to create more accurate models of pollutant transport
 and effects that cross the boundaries of air, water, and soil?
 Ecological Indicators - What can measurements of plants and animals
 reveal about their past exposure to harmful pollutants or other
 environmental stressors?

 Regional Vulnerability Assessment - How can we compare and
 identify the greatest risks to ecosystems as a result of increasing
 population and economic growth in a region?
Research and Technical Support for Regulatory
Programs                         ,.  ..	
NERL scientists provide a wide range of research and regulatory— -
technical support to EPA program and regional offices, and to the
States and foreign governments. In particular, NERL provides
substantial support in regulatory monitoring methods, waste site
characterization, computer modeling of pollutant transport and fate,
remote sensing, monitoring network design, environmental
indicators, and design of exposure assessment studies.  NERL's
Center for Exposure Assessment Modeling distributes and supports a
variety of multimedia and ecosystem response models for users
throughout the world. The Environmental Photographic
Interpretation Center (EPIC) is EPA's primary source of interpreted
remote sensing data. The Technology Support Center for Monitoring
and Site Characterization provides scientific and technical assistance
for hazardous waste site characterization. NERL recently has lent
considerable technical support in monitoring technology and
exposure assessment to Canada, Mexico, Germany, Poland, Malaysia,
and Indonesia, and supports many international scientific symposia.

National Exposure Research Laboratory
Director, Dr. Gary J. Foley

Acting Deputy Director, Jewel Morris
Associate Director for Health, Dr. Judith Graham
Acting Associate Director for Ecology, Dr. Jay Messer
                                       Printed on Recycled Paper

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