ATSDR -- FY 1999 AGENCY PROFILE AND ANNUAL REPORT
Fate and Transport Models
"Fate and transport" refers to the movement of a hazardous substance
from its source through the environment, until it comes into contact with
people. Scientists have developed mathematical models that predict the fate
and transport of hazardous substances through the environment. These models
predict how chemicals travel through the environment, how they break down,
and how key physical and chemical properties of chemicals (including water
solubility, volatility, and soil adsorption) affect the potential for exposure. One
such model is ATSDR's Analytical Contaminant Transport Analysis System
(ACTS) software package. ACTS is designed for use as a "screening level" tool
that helps health assessors understand basic concepts of fate and transport of
contaminants within an environmental system.
Exposure Investigations
Exposure investigations are conducted to gather and analyze site-specific
information to determine if human populations have been exposed to
hazardous substances. Information is obtained through biomedical testing,
environmental testing, and exposure-dose reconstruction. Biomedical testing
(e.g., urine or blood samples) can show current (and sometimes past) exposure
to a contaminant. Environmental testing (for contamination of soil, water, or
air) is focused on where people live, spend leisure time, or might come into
contact with contaminants under investigation. Exposure-dose reconstruction
analyses use environmental sampling information and computer models to
estimate the contaminant levels that people may have been exposed to in the
past or may be exposed to in the future. Estimations of the exposure dose are
used to evaluate how a person's health might be affected. The results of
exposure investigations are used to make public health decisions and to
recommend appropriate public health actions.
Exposure-Dose Reconstruction Modeling
Often not enough information is available about a community's past
exposures to estimate health risks. Therefore, researchers have to reconstruct
levels of hazardous substances that people may have been exposed to and the
length of time they were exposed. Exposure-dose reconstruction modeling is
used to estimate the patterns of movement and concentrations of contaminants
from the source via a variety of environmental media. ATSDR researchers use
computational models to test a variety of exposure estimates and make
recommendations based on scientifically accepted techniques and procedures.
Below are several examples of public health activities ATSDR conducted
in FY 1999 using new technologies.
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