Evaluation of the Genotoxicity of Petroleum Refinery Effluents Using the Comet Assay in Oreochromis niloticus (Nile tilapia)

In this study, the genotoxic effects of effluent and water samples from areas (Atibaia and Jaguari rivers) related to a petroleum refinery were assessed by comet assay carried out in erythrocytes of Oreochromis niloticus (Nile tilapia). It was registered, for the negative control test (pure ground water), the lowest levels of nucleus with damage, followed by the waters collected in the Jaguari river (environmental control). It was observed a higher level of nucleus with damage in the fishes exposed to the refinery effluents samples, which decrease with the increasing treatments levels. It was also observed, in relation to the negative control, a genotoxic effect in the Atibaia river sample collected after the effluents discharge. The results showed that, even after the treatments, the petroleum refinery effluents induced genotoxicity in the exposed fishes.