Determination of Heavy Metal Concentration in Fish Samples, Sediment and Water from Odo-Ayo River in Ado-Ekiti, Ekiti-State, Nigeria

Abstract

This research work was conducted to assess the concentration of heavy metals namely, Zn, Mn, Cu, Fe, Pb and Cd in three matrices including sediment, water and Fish organs (gills, flesh, kidney and liver). The fish sample, Clarias gariepinus was collected from Odo-Ayo River in Ado-Ekiti, Ekiti State, Nigeria. The results obtained showed that the concentration of heavy metal in water (Zn-4.65, Mn-0.79, Cu-0.84, Fe-5.87, Pb-0.16, Cd-0.13) was lower than that of the concentration of heavy metal in sediment (Zn-5.04, Mn-0.98, Cu-1.37, Fe-6.94, Pb-0.30, Cd-0.20), While the concentration of heavy metals in water was higher than that of fish parts (Zn-0.95, Mn-0.82, Cu-0.66, Fe-1.09, Pb-0.09, Cd-0.04). This confirms that sediments are repository of metals in water. The concentration of heavy metals recorded in the fish parts also indicated a certain degree of bio-accumulation. The concentration of all metals in water were below the WHO and FEPA recommended limits and suggested that the water of Odo-Ayo River was suitable for drinking, but the bio-concentration factor of heavy metals in gills, kidney and liver of the fish are high beyond the tolerable level, which indicated that as far as these metals are concerned, the fish is unfit for human consumption. Consequently, close monitoring of metals pollution and the consumption of the fishes of Odo-Ayo River is recommended with a view to minimizing the risk of health of the population that depend on the river for their water and fish supply.