Genetic damage in the bivalve mollusk Corbicula fluminea induced by the water-soluble fraction of gasoline.

Although gasoline is an important contaminant of aquatic ecosystems, information concerning the potential effects of this petroleum derivative on the DNA of aquatic biota is lacking. The present study aimed to evaluate the genotoxic and mutagenic effects of acute exposures (6, 24, and 96h) to gasoline water-soluble fraction (GWSF), diluted to 5%, on the Asian clam Corbicula fluminea. The comet assay and the micronucleus (MN) test were performed on hemocytes and gill cells of C. fluminea. For the three different times tested, the comet assay indicated DNA damage in hemocytes and gill cells of C. fluminea exposed to GWSF. The MN test detected significant damage in the genetic material of the hemocytes only after 96h of exposure to GWSF. The recovery capacity of organisms previously exposed for 6h to GWSF was also evaluated with the comet assay. The results revealed a great capacity of this species to repair DNA damage; following 6h of recovery, the comet score returned to that of the control groups. Overall, our findings indicate that GWSF has genotoxic and mutagenic effects on C. fluminea. In addition, the present results confirm the sensitivity of C. fluminea to damage caused by exposure to environmental contaminants, and, therefore, its suitability for use in environmental monitoring studies.