Concentration levels of trace metals in fish and sediment from Kubanni river, Northern Nigeria
ABSTRACT The concentrations of six trace metals (Pb, Zn, Cu, Cr, Ni and Cd) in fish and sediment samples from Kubanni River located in Zaria, Northern Nigeria, were investigated. The river receives agricultural runoff and municipal wastewaters, and is utilized for drinking, fishing and irrigation. Fractionation of trace metals in the river sediments, the risk to water column contamination and the levels of the six trace metals in Clarias gariepinus and Oreachromis niloticus samples were established. There was considerable risk to river water contamination based on the calculated individual trace metal average contamination factors (IACF) obtained for the river sediments from the trace metal sequential extractions. Also, the distribution and concentration of trace metals obtained in liver, gill, muscle and bone of C. gariepinus and O. niloticus showed that the human health risk for trace metals in muscles of fish were low, but individuals consuming fish livers might be at risk from ingestion of toxic metals at unacceptable concentrations.