HUMAN HEALTH RISK ASSESSMENT OF HEAVY METAL LEVELS IN Clarias gariepinus AND Parachanna obscura FROM THE IKPOBA RIVER, EDO STATE, NIGERIA

Abstract

The purpose of this paper is to evaluate the accumulation of heavy metals (Ni, Zn, Pb, Fe and Cr) in two commercially available fishes Clarias gariepinus and Parachanna obscura, and estimate the health risks they pose to humans through consumption. Fish samples were collected between July and October, 2017. Heavy metals were determined using the Atomic absorption Spectrophotometer while health risk to consumers was evaluated using Estimated Daily Intake (EDI), Target Hazard Quotient (THQ) and Hazard Index (HI).  Heavy metal accumulation followed the order Fe>Cr>Zn>Pb>Ni and Cr>Fe>Zn>Pb>Ni in the liver and muscle of Clarias gariepinus while concentrations in the liver and muscle of Parachanna obscura followed the order Fe>Pb>Cr>Zn>Ni and Fe>Cr>Zn>Pb>Ni respectively. Chromium and lead exceeded the permissible limits for fish food. Target Hazard Quotient was Cr >Pb> Ni with values of 0.040, 0.014 and 0.002 for C. gariepinus and 0.013, 0.010 and 0.002 for P. obscura. The Hazard Index was 0.056 and 0.025 for C. gariepinus and P. obscura respectively. The hazard indexes for the two fishes were below one and thus indicate minimal risk of health concerns to consumers of these fishes. Regular monitoring of heavy metal levels in fishes is recommended.