ASSESSMENT OF GENETIC DAMAGE AS A
BIOMARKER IN THE REMEDIATION OF
CONTAMINATED OR POLLUTED SITES
S.K. Fisher1, C.H. Jagoe1,2, C.E. Dallas1, R.K. Chesser2, M.H. Smith2, and I.L. Brisbin1,2, Jr.
1Department of Pharmacology and Toxicology, College of Pharmacy, University of
Georgia, Athens, GA 30602 USA
2University of Georgia, Savannah River Ecology Lab, PO Drawer E, Aiken, SC 29802
Knowledge of the biological consequences of exposure to contaminants at a
particular site can assist in deciding whether cleanup is warranted, and
determining when it is complete. Acute effects of exposure to environmental
contaminants, such as increased mortality or severe physiological dysfunction are
relatively easy to detect. Long term effects of chronic exposure to sublethal
levels of contaminants can be much more difficult to determine. Chronic
exposure to environmental toxicants can alter biological processes including
metabolism, growth, and reproduction. These alterations may then cause
changes at the population and community levels. Such effects are often gradual
or subtle, and it may be difficult to determine responses to a particular pollutant,
especially in systems which contain multiple contaminants.
Biological monitoring uses the affected organisms to integrate exposures over
space and time. For this approach, selected "biomarkers" are evaluated in
organisms living at the polluted site and compared to those measured in control
organisms. The selected biomarkers may be anatomical, physiological, molecular
or ecological, and represent the actual consequences of exposure to the
pollutants of concern to wild organisms in the field. By combining the traditional
substance monitoring approach of measuring levels of contaminants in the
environment with biological monitoring, a much better picture of the hazards
associated with a polluted area can be obtained.
To determine chronic effects in individuals and long term effects on populations
due to pollution, a promising biomarker involves changes in genetic material.
Many contaminants of special concern are mutagenic or carcinogenic. Screening
for deoxyribonucleic acid (DNA) damage is useful for identifying such effects
due to both chemicals and radionuclides, particularly when several potential
toxicants are present. We are presently employing techniques to assess potential
genetic damage associated with contaminant exposure at several sites. Studies
include largem6uth bass, turtles and mallard ducks exposed to mercury and low
levels of radiation at the Savannah River Site, crucian carp and molluscs
exposed to radioactive contamination in the Chernobyl region in Eastern Europe,
and bullhead catfish exposed to PAHs at polluted sites in Ohio. Other workers
are using similar techniques to evaluate genetic damage due to heavy metals,
organic pollutants and radiation in both vertebrate and invertebrate species.
SREL Reprint #1815
Fisher, S.K., C.H. Jagoe, C.E. Dallas, R.K. Chesser, M.H. Smith, and I.L.
Brisbin Jr. 1993. Assessment of genetic damage as a biomarker in the
remediation of contaminated or polluted sites. p. 629-634. In Proceedings of the
U.S. Department of Energy Environmental Remediation Conference, U.S.
Department of Energy. Augusta, GA.
To request a reprint