Estimation of the level of deposited lead in upper, middle and lower courses of river Jebba in Niger State, Nigeria

Abstract

Metals accumulating in tissues and organs of aquatic organisms due to their ability to bio-accumulate in aquatic ecosystems. Heavy metals generally enter the aquatic environment through natural and anthropogenic activities caused by individual effluent, domestic sewage, mining and agricultural wastes. This study is aimed at assessing the level of accumulated Lead (Pb) in the samples of four different species of fish found in the river (these includes: Synodontis membranacea, Bagrus bayad, Hydrocynus forskalii and Mormyrus rume), water and sediments sample collected from different courses of the river. The collected samples were analyzed using Atomic Absorption Spectrophotometer (AAS) at the laboratory of Nigeria Institute of science and laboratory Technology (NISLT), Ibadan. The results from this research showed that Hydrocynus forskalii (Tiger fish) has the highest bio-accumulated concentration of Lead (0.0685±0.006 mg/kg) while Synodontis membranecea (Karaya) shows the lowest level of deposited lead out of the species of fishes found in the river. It was discovered that water collected from station A (upstream) had the highest level of deposited Lead (0.93±0.031mg/ml) and water samples collected from station C (downstream) had the lowest level of deposited Lead (0.59 ± 0.01mg/ml). Also, the Sediment samples from the river shows the highest concentration of Lead (1.62±0.013 mg/Kg) at station A (upstream) while the lowest concentration (0.97±0.027 mg/Kg) of Lead (Pb) was noticed at the station C (downstream). However, all samples analyzed revealed values that are far above the permissible level of concentration in an aquatic environment.