GENOTOXIC EFFECT OF EXPOSURE TO VERY LOW CONCENTRATION OF PARAQUAT

ABSTRACT

The occurrence of herbicides in our environment as a result of the indiscriminate or intentional use has resulted in its persistence in the environment, thereby affecting the ecosystem and nontarget organisms. The aquatic ecosystem is under increasing pressure from environmental contaminants due to anthropogenic activities. Adverse effects caused by herbicides has forced scientists to develop an alternative against the synthetic herbicides. This study investigated the potential of Paraquat dichloride (Parmor) to induce DNA damage and other cell abnormalities in juvenile African Catfish, Clarias gariepinus. Juvenile fish were exposed for 96 hours under laboratory conditions. Significant concentration-dependent increase (p<0.05) in mortality rates was established. Respiratory disturbance, erratic swimming, loss of equilibrium, lethargies and sudden death were observed in the exposed fish and these varied greatly with increase in concentration of the Parmor. Comet assay or alkaline single-cell gel electrophoresis (SCG) was performed in fish Clarias gariepinus after exposure to different concentration (0.03ml, 0.06ml, 0.1ml, 0.13ml) of paraquat dichloride (parmor. The assay was carried out in the gill, liver, and gonads. The genotoxic potential of “Parmor” herbicide on Clarias gariepinus gills shows that as the concentration of herbicides increases. The genotoxic potentials of herbicides on Clarias gariepinus increases at concentration 0.03 to 0.13ml increases from 3 to 22. And the liver genotoxic effect increases at the concentration increases 5 – 19. In conclusion this causes a significant genetic damage in the study organs of Clarias garienpinus.