The
toxicity and
genotoxicity of
wastewater from eight
gasoline stations in Brasília,
Brazil's
capital city, was studied by assessing
chromosomal aberrations, chromosomal malsegregation and the
mitotic index in
Allium cepa root
cells, and the occurrence of micronucleus and nuclear
abnormalities in peripheral
erythrocytes of
tilapia fish (
Oreochromis niloticus). The content of
gasoline station effluents was also analyzed based on several physico-chemical
parameters. None of the
wastewater samples was genotoxic to A. cepa root
cells, although
cell proliferation was significantly inhibited, especially at the highest concentrations. Likewise, no micronuclei were observed in O. niloticus peripheral
erythrocytes, even after exposure to high concentrations, but there was an increase in the number of nuclear
abnormalities and fish
mortality. These results show that although the effluent from
gasoline stations is processed by an oil/
water separation system before being discharged into the main
sewage system, the
wastewater still contains toxic compounds.