D.I. Olorunfemi

Petrol station attendants are occupationally exposed to petroleum products and it’s fumes which represents complex mixture of genotoxic agents that possesses an increased risk of various cancers such as that of the oral mucosa. This study assessed the level of genotoxic damage in exfoliated buccal cells obtained from petrol station attendants within Oluku Axis, Benin City, Edo State, Nigeria. Twenty - five exposed petrol station attendants were recruited from five filling stations which includes;
thirteen females and twelve males whose duration of exposure is within zero to five years while nine unexposed healthy individuals were recruited fromthe University of Benin. Buccal cell samples were collected by scrapping of the inner cheeks which was fixed with Carnoy’s reagent and stained using May - Grunwald and Giemsa stains, after which it was analyzed using a light microscope at 100x magnification. A total of 3400 cells were examined for micronuclei and other anomalies such as binucleated and anucleated cells. A significant increase in the frequencies of micronucleated cells, binucleated cells and anucleated cells (12.50, 6.17 and 6.00) with (p < 0.05) were found in the workers exposed as compared to the controls (0.67, 4.50 and 3.33)
respectively. These findings indicate that continuous exposure to benzene have the potential to induce anomalies reflecting DNA strand breaks. This study concludes that petrol station attendants within Oluku Axis experience measurable genetic damagelinked to occupational exposure to petroleum products. It recommends that protective strategies should be implemented by the concerned authorities to minimize exposure to petroleum products.

The discharge of wastewater into waterbodies without proper treatment has led to several threats such as DNA damage to aquatic species. This study evaluates the genotoxic effect of cassava wastewater on the gonads, liver and gills of post juvenile Clarias gariepinus using comet assay. The post juveniles of Clarias gariepinus was purchased from fish farm located in Delta State and was exposed to various concentrations (0.2%, 0.3%, 0.5%, 0.7%) of cassava wastewater for 96 hours. Unlike normal behaviours observed in the control groups, the fish exposed to the effluent were restless, erratic in their movement and gasping for breath. After the exposure period, the fishes were transported to the laboratory and the cells of their liver, gills and gonads were extracted for genotoxic assessment using comet assay. The result obtained from the genotoxic assessment revealed DNA damage at varying concentrations of the wastewater. The study revealed that genotoxins present in the wastewater were obviously responsible for the DNA damage in the tissues in the organism. The study also revealed that the genotoxic effect of cassava wastewater on post juveniles of Clarias gariepinus is dose
dependent as DNA damage increases with increased concentration. This study shows that the treatment of wastewater before disposal is very important.