Abstract

Increasing contamination of aquatic environment as a result of indiscriminate discharge of solid wastes and effluents has become a global issue of environmental concern. There are harmful substances contained in the wastes and effluents which create a major problem on the quality of the Nigerian coastal water. This study evaluated the human health and ecological risks of Cu, Pb, Zn and Hg in Sarotherodon melanotheron from Lagos Lagoon, South-Western Nigeria. The metals’ concentrations were determined in the fish, using atomic absorption spectrophotometer. Health risk assessment of consumers from the intake of metals in the fish was evaluated by Health Risk Index (HRI) and Health Quotient (HQ). Ecological Risk Quotient (ERQ) was also calculated. The metal levels in the fish are in decreasing order Zn (0.026±0.04mg/kg) > Cu (0.011±0.01mg/kg) > Pb (0.0008±0.00mg/kg) > Hg (0.000±0.00mg/kg) and fell below the recommended limit by Environmental Protection Agencies. HRI and HQ of each metal was less than one, indicating that there was no potential health risk associated with the consumption of S. melanotheron from Lagos Lagoon. The Ecological Risk Quotient (ERQ) was also found to be less than one (ERQ<1). This indicated that S. melanotheron did not constitute any ecological threat to the Lagos lagoon.

Key Words: Food Safety and Security, Environmental Pollution, Heavy metals, Lagoon