SREL Reprint #1815

 

 

 

 

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 USA

ABSTRACT

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.

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