The effects of heavy metals concentration on some commercial fish in Ogun River, Opeji, Ogun State, Nigeria

Abstract

A study was conducted on commercially important fish species of heavy metals in water bodies. The primary objectives were to find out the amount of heavy metals concentration in the fish species, sediments and water samples at the deep and shallow part of the river, to determine the toxicity and relationship between the collected samples and the rate at which it pollutes the water. Atomic absorption spectrophotometer (AAS) evaluates their wholesomeness for human consumption. Four heavy metals (lead, cadmium, copper and zinc) were analyzed and only copper and zinc were found to be present in the digested samples. The concentration of copper in the fish (flesh) was 0.09 mg/l and that of zinc was 0.25 mg/l. In the bone samples, copper was found to have 0.17 mg/l and zinc 0.22 mg/l. In the water samples analyzed, the concentration of copper is 0.035 mg/l while that of zinc is 0.047 mg/l. In the sediment sample, the amount of copper is 310.0 mg/kg while that of zinc is 2050.0 mg/kg. This however signifies that the fish species in the Ogun River as well as the water is suitable for consumption which was found to be less than the World Health Organization (WHO) maximum recommended acceptable limits in the food.

Key words: Heavy metals, fish species, water samples, toxicity