THE ASSOCIATION OF DNA-DAMAGE TO CONCENTRATIONS OF MERCURY AND RADIOCESIUM IN LARGEMOUTH BASS

Largemouth bass from five lakes were examined to determine levels of c ontamination by mercury acid radiocesium and amounts of DNA damage. Co ncentrations of these toxicants and an index of body condition were re gressed against overall DNA damage and DNA damage in individual tissue s (liver, gills, and red blood cells) as indicated by the alkaline unw inding method. Sample sites showed considerable heterogeneity in conce ntrations of mercury and radiocesium, as well as numbers of DNA strand breaks. Generally, increased concentrations of toxicants were related to increased DNA damage. Tissues may have responded to contaminants i n different manners; red blood cells generally showed the greatest DNA damage while liver tissue showed the least. Although body condition w as related to DNA damage, it is unclear whether it has a direct effect or whether it is a correlated response to contamination by mercury an d radiocesium. The potential for repair of DNA strand breaks and cell turnover rates may play an important role in determining the ultimate amount of DNA damage in contaminated organisms.