DETERMINATION OF HEAVY METALS (Cd, Pb, Ni) IN TILAPIA FISH, CRAB AND PERIWINKLE FROM TOMBIA RIVER IN RIVERS STATE.

Abstract

Fish and other seafood are important sources of human protein. Seafood is currently accepted as essential food for humans and widely consumed by many. Therefore, there is need for the evaluation of heavy metals in seafood to reduce health risk of these metals. This study was carried out to determine the levels of lead (Pb), cadmium (Cd) and Nickel (Ni) in crab, fish and periwinkle from the Tombia River in Rivers State. Samples were oven dried and ground into powder before acid digestion with aqua regia and analyzed using atomic absorption spectrophotometer. The results showed that the average concentration of Pb was 42.82± 0.601 mg/kg in crab, 18.05± 0.071 mg/kg in fish and 15.85± 0.078 mg/kg in periwinkle. Ni was 9.69± 0.085 mg/kg in crab, 8.23± 0.106 mg/kg in fish and 4.53± 0.177 mg/kg in periwinkle while the values for Cd were 4.75± 0.071 mg/kg in crab, 3.00± 0.056 mg/kg in fish and 2.87± 0.113 mg/kg in periwinkle. Average concentrations of Pb were found to be higher than other metals in the three seafoods studied. Based on the results obtained from this study crab, fish and periwinkle from Tombia River were found to be contaminated with Cd, Ni and Pb and their levels were found to be higher than the permissible limits set by WHO. Frequent consumption of these seafoods from this river may cause biochemical changes in humans and also lead to organ dysfunction as these metals have been categorized as carcinogens.