Health Risk Assessment of Heavy Metal Contamination in Edible Fish Species from the Barekese Reservoir in Kumasi, Ghana

Heavy metal pollution and its resultant accumulation to toxic levels in the Barekese reservoir may threaten human health through the consumption of fish from the Reservoir. The presence and concentrations of arsenic and some other heavy metals (Hg, Pb, Ni, Cr, and Cd) were determined in muscle tissues of widely distributed and highly consumed fish species from the Barekese reservoir using Atomic Absorption Spectrophotometry. A total of 45 fish samples comprising three species (Oreochromis niloticus, Tilapia zilli and Heterotis niloticus) were analyzed for their metal levels. Heavy metals concentrations (mg/kg, w.w) showed varying trends of detection among muscle tissues of selected fish species. However, Hg, Ni, Cr and Cd were detected in muscle tissues of all fish species examined in the study. Indices for non-carcinogenic and carcinogenic risks were estimated for child and adult upon their consumption of fish from the Reservoir. Results of the study indicate a significant level of exposure to Hg, Ni, Cr and Cd through the consumption of fish species from the Reservoir. Health risk assessment also revealed that children are at a relatively higher non-carcinogenic risk through the consumption of metals in Heterotis niloticus (HQ = 2.95 × 10-1). Also, the consumption of all examined fish species from the Reservoir pose no significant cancer risk effects to humans. The present study, therefore, concludes that anthropogenic activities along the Offin River and within the Barekese reservoir’s catchments could lead to deteriorating the quality of fish from the Reservoir hence regular monitoring of such activities is needed.