Health risk assessment of organochlorine pesticide residues in freshwater fish in Ibadan, Nigeria.

This work was aimed at assessing the potential human health risk of organochlorine pesticides (OCPs) due to consumption of five different species of fish from Dandaru River and Eleyele Lake in Ibadan, Nigeria. Five OCPs (aldrin, beta-lindane, beta-endosulfan, endosulfan ether and heptachlor epoxide) were investigated. Extraction was carried out by a quick, easy, cheap, effective, rugged, and safe (QuEChERS) procedure; extract was cleaned-up using solid phase extraction while instrumental analysis was performed by gas chromatography-mass spectrometry. Health risk assessment (non-carcinogenic and carcinogenic) to adult, children and infants was carried out using standard models and indices. Target OCPs were measured up to 0.013 mg/kg for heptachlor epoxide in Oreochromis niloticus from Dandaru River. Lowest concentrations for most of the OCPs were determined in Clarias gariepinus from Eleyele River. Hazard indices (HI) indicate that non-carcinogenic risk to adult and children was not apparent by consuming all investigated fish species from Dandaru River and Eleyele Lake. However, a high non-carcinogenic risk to infants was expected by consuming Oreochromis niloticus and Oreochromis lidole from Eleyele Lake as well as all investigated fish species (except Oreochromis aureas) from Dandaru River, apparently due to the contribution of heptachlor epoxide. Although carcinogenic risk was not expected in adult due to consumption of all investigated fish species from both Eleyele Lake and Dandaru River, consumption of Oreochromis niloticus from Eleyele Lake by infants and children, Oreochromis lidole from Eleyele Lake by infants, as well as all investigated fish species (except Oreochromis aureas) from Dandaru River by infants poses possible carcinogenic effects. Regular health risk assessment of target OCPs for the investigated fish species from the two water bodies is necessary to safeguard the safety and health of consumers, especially infants.