Metal Levels in Tillapia zilli, Clarias lazera and Barbus lagoensis from River Hadejia and the Effects on Renal Failure

Abstract

Dietary exposure to toxic metals has been identified as a risk to human health due to large amounts of these metals disposed of in the environment either as industrial waste or other sources due to human activities. In this study, three species of fishes (Tilapia zilli, Clarias lazera and Barbus lagoensis) were obtained, air-dried, milled and digested. The digested samples were analyzed for cadmium, chromium, lead and mercury using atomic absorption spectrophotometer (AAS). The results of the analysis showed that the concentration of cadmium in Tilapia zilli (0.0088mg/kg) and Barbus lagoensis (0.5134mg/kg) were higher than the maximum permissible level (0.003mg/kg) of cadmium in food and water. Similarly, chromium concentration in Barbus lagoensis (0.069mg/kg) was higher than the permissible level (0.05mg/kg). Also, concentrations of lead in Clarias lazera (0.019mg/kg) and Barbus lagoensis (0.0739mg/kg) were above the maximum permissible level (0.01mg/kg) in food and water as recommended by the standard organization of Nigeria. The findings also revealed that mercury concentration in Tilapia zilli (0.0058mg/kg) was high and above the maximum permissible level (0.001mg/kg) stated in SON regulations. This study confirms the increased danger of consuming fish that is contaminated with these heavy metals, and if it is allowed to continue, long-term exposure may lead to kidney failure and other diseases associated with these heavy metals. Proper monitoring and enforcement by regulatory agencies are required.