Concentration of Heavy Metals and Health Risk Assessment of Consumption of Fish (Sarotherodon melanotheron) from an Estuarine Creek in the Niger Delta, Nigeria

Abstract

Health risk assessment with respect to heavy metals concentration and consumption of fish (Sarotherodon melanotheron) obtained from Azuabie creek was carried out. Five fish samples composited were obtained from fishermen on a monthly basis from January - December 2015. Heavy metals (Cr, Ni, Cu, Pb, Ag and Cd) analysis was done using Atomic Absorption Spectrophotometery while health risk to consumers was evaluated using Estimated Daily Intake, Target Harzard Quotient, Hazard Index and Target Cancer Risk. Metal concentration in fish tissue were Cu > Pb> Cr > Ni > Ag > Cd with the following mean values 5.59 ± 1.06 mgkg-1, 5.12 ± 1.23 mgkg-1, 2.69 ± 1.44 mgkg-1, 1.94 ± 0.34 mgkg-1, 1.02 ± 0.34 mgkg-1 and 0.38 ± 0.08 mgkg-1 respectively. Ni, Pb and Cd had mean values above recommended FAO/WHO limits. EDI values (mgkg-1 bw/day) were Cu 0.93 x10-3, Pb 0.85 x 10-3, Cr 0.45 x 10-3, Ni 0.32 x 10-3, Ag 0.17 x 10-3 and Cd 0.063 x 10-3. THQ values were as follows: Cr 0.29, Pb 0.24, Cd 0.06, Cu 0.023 and Ni 0.016 while the HI for all metals had a value of 0.64 and the TR for Ni had a value of 2.63 x 10-3mgkg-1 bw-day-1.The study concluded that fish muscle obtained from the study area showed bio-accumulation of metals over time but health risk assessment indices indicated minimal to moderate risk levels suggesting insignificant health risk. This could douse public health concerns in terms of human exposure via consumption of fish but regular monitoring is advised to detect changes in metal concentration.