Analysis of heavy metals concentrations in commercially available fish from The Yola-Jimeta region, Northeastern Nigeria and Public-Health implications

Abstract

Commercially available (farmed and wild) fish in the Yola-Jimeta region, Northeastern Nigeria were investigated to find out if they present a public health threat. The fish species used for the study was catfish from the farm and the wild (Benue River) fish. The concentrations of six heavy metals were analyzed. These metals include: cadmium (Cd), iron (Fe), zinc (Zn), manganese (Mn), lead (Pb), and nickel (Ni). The metal concentrations were obtained using atomic absorption spectrophotometer (AAS). The results from AAS were expressed as part per million (ppm) and converted to µg/g dry weight in the result section. The result shows that the gills of farmed fish with exception of manganese accumulate more metals than in the flesh. However, the flesh of wild fish has significantly higher metals concentration than in the gills. Nevertheless, concentrations of heavy metals were higher in the gills of farmed fish but the results were not statistically significant except for lead and zinc. In addition to this, the concentrations of lead, nickel, and cadmium in both the tissues of farmed and wild fish except for zinc in the gills of farmed fish were above the recommended levels provided by WHO.