چكيده لاتين :
This study focuses on Pb bioaccumulation in the different tissues of the African catfish (Clarias gariepinus). Ten Clarias gariepinus were randomly allotted to each of experimental groups A-E and exposed to sublethal concentrations (0.0, 0.05, 0.1, 0.5 and 1 mg L^-1, respectively) of lead nitrate in triplicates. Bioconcentration of lead was between 9-600 and 20.2-800 mg kg^-1 at 4 and 8 weeks, respectively in different tissues. Rate of bioconcentration of lead in tissues decreased with increase in lead concentration in culture water. The heart generally had the highest metal concentrations. The liver, in its role as a storage and detoxification organ, also accumulated high levels of lead. Muscles and skin accumulated much less lead concentrations. The lowest lead concentration (10.28 mg kg^-1) accumulated in the muscle of fish sampled from commercial fish ponds. This study has shown that lead pollution is of hazardous proportions in Ibadan and environs. This has severe consequences on aquatic fauna and humans who consume such contaminated fish and shellfish. It is therefore recommended that human and animal health surveillance and environmental monitoring of lead be more intensified. Skin and muscles should also be included in biomonitoring programmes, because they are consumed by the general public.
