Freshwater is a vital medium by which fish for human consumption are cultured, thus, preserving its quality is essential. The presence and bioaccumulation pattern of some heavy metal concentrations in wild African Catfish, Clarias gariepinus (Burchell, 1822) muscles and water samples, collected from River Kaduna during the dry season month of December was assessed, to determine their concentrations, physico-chemical parameters, and risk evaluation of selected metals and their effects on fish quality. Analysis was carried out using standard analytical procedures and methods. Risk assessment for Fe, Pb, Ni, Cd, and Hg were based on average daily dose, hazard quotient, and cancer risk was also determined. Result showed that physico-chemical parameters, were within WHO recommended threshold limits, and mean concentrations of heavy metals followed the order Fe>Pb>Hg>Ni>Cd. Carcinogenic risk ( ) via ingestion of fish muscles for Pb, Hg and Cd were higher than the acceptable limit (10 -6 ). Anthropogenic activities, especially indiscriminate waste disposal were suggested as the main contributor to environmental pollution. Findings reveals possible health implications, thus constant surveillance was suggested to guide appropriate response.

The likely health risks developed as a result of human contamination by heavy metal through fish consumption was assessed in this study. The analysis of wild and farmed fish for heavy metals was determined and an assessment of the risk limits was evaluated through daily intake of metal and health risk index. Heavy metals accumulations varied in concentrations in the various tissues/organs (skin, muscle, gills, liver, intestine, kidneys, brain, and bones) across the groups of farmed and wild fish species (Clarias gariepinus). A post-hoc multi-comparison (Duncan Multiple Range Test) showed that there were significant differences ( < 0.05) across analysed samples. The analysis of heavy metals concentrations, in the investigated tissues of Clarias gariepinus, showed levels of heavy metals accumulations in the order: Fe>Hg>Pb>Cd>Ni and were all below the recommended safety limits outlined by FAO/WHO. Furthermore, the consumer's health risk with the consumption of fish muscles tissues shows that there are very negligible tendencies for cadmium, lead, and mercury exposure. Also the ingestion of Clarias gariepinus with heavy metal concentrations indicated in this study is within the FAO/WHO safety daily intake limits (also specified in the study) and would not result in accumulation of heavy metals at intolerable concentrations, thus health complications arising from accumulation of heavy metals are rare.