LAUSR

ABSTRACT The health risks of polychlorinated biphenyls (PCBs) levels in fish and sediment from River Niger (Onitsha axis) was investigated. Fish and sediment samples were collected during dry and rainy seasons from upstream and downstream of the river. Extraction was carried out using n-hexane: acetone mixture (50:50) and PCBs were determined using gas chromatography-electron captor detection. Average recovery of 97.67% was obtained for fish and 95.88% for sediment. PCBs concentration and biota-sediment accumulation factor (BSAF) were higher downstream for both seasons. There was no significant difference (P < 0.05) in PCBs concentration between dry and rainy seasons. Concentrations of PCBs in fish were below the Food and Drug Association (FDA, 2018) tolerance level of 2 ppm. Also, noncarcinogenic hazard quotient (HQ) for PCBs congeners in fish samples were ˂1, which indicates no noncarcinogenic health risks from consumption of fish from Niger River. However, carcinogenic HQ for normal fish consumption in children was above 1 in some sample locations but below 1 for adults. Also, carcinogenic HQ for habitual fish consumption was above 1 in some sample locations for both children and adults. There is presence of PCBs in River Niger as a result of anthropogenic activities and industrial discharges, with human risks especially for children.