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 contamination by mercury and radiocesium and amounts of DNA damage Concentrations of these toxicants and an index of body condition were regressed against over all DNA damage and DNA damage in individual tissues (liver, gills, and red blood cells) as indicated by the alkaline unwinding method Sample sites showed considerable heterogeneity in concentrations 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 in different manners, red blood cells generally showed the greatest DNA damage while liver tissue showed the least Although body condition was related to DNA damage, it is unclear whether it has a direct effect or whether it is a correlated response to contamination by mercury and 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