Analyses of Heavy Metals Bioaccumulation in the Organs of Clarias gariepinus Following Exposure to Sub-Lethal Concentrations of Waste Burnt Tire Residues

Abstract

This study evaluated the bioaccumulation of certain heavy metals of waste burnt tire residues (WBTRs) in certain organs (viz-gills, liver, kidney and muscles) of Clarias gariepinus following exposure to sublethal concentrations (SLCs) of water-soluble fractions (WSFs) of WBTRs. Clarias gariepinus (average weight of 47.95±0.34g and length of 15.54±0.36cm) were exposed to SLCs at different concentrations (0.00, 0.23, 0.47, 0.94, 1.87, and3.74 ppm) of WSFs of WBTRs for a period of fifty-eight days. Heavy metal concentrations in WBTRs and in the organs of the experimental fish were measured using a handheld X-Ray Fluorescence Analyzer (NitonXL3T). Results showed that strontium, lead, zinc, cobalt, bismuth, rubidium, gold, tungsten, iron, thorium, arsenic, copper, and niobium were detected in WBTRs although the maximum level of zinc was perceived however, no significant difference (P>0.05) was observed as compared to the control group regarding heavy metal accumulation in muscles, 53.10±12.78; liver, 56.30±76.96; kidney, 164.54±12.78; and gills, 241.36±146.87 of the exposed fish. The high levels of heavy metals present in WBTRs are of great concern as potential detrimentl pollutants to the aquatic ecosystem. These allochthonous inputs get into the aquatic ecosystem through sewage flow and runoffs effluents. Resident non-target communities particularly fishes from such polluted aquatic systems with WBTRs become vunerable and incriminated with attendant high levels of heavy metals that could be detrimental to human consumers.