Human Health Risk Assessment from the Tilapia Fish in Heavy Metal Contaminated Landfill Reservoir

This study revealed the significant environmental and health risks posed by heavy metals contamination in Oreochromis niloticus (Nile tilapia) near landfill sites. It also assessed potential human health risks and investigated genotoxicity and oxidative stress in fish. Heavy metal concentrations were measured using Inductively Coupled Plasma Optical Emission Spectrometry. Results indicated that all four metals in water samples exceeded safety limits, and Cd levels in sediment were also above regulatory thresholds. In fish muscle, metal concentrations followed the order Cr > Pb > Cd > As, with Pb exceeding food quality standards. The bioaccumulation factor ranked as Cr > Pb > As > Cd. Health risk assessments, including the health risk index and carcinogenic risk analysis, suggested Pb contamination poses significant health risks through fish consumption. Genetic analysis showed greater genetic differentiation in landfill-site fish compared to reference-site fish, indicating genotoxic effects. Oxidative stress markers revealed higher levels of malondialdehyde, hydrogen peroxide, but lower activities of catalase and superoxide dismutase in landfill fish. These results emphasize the urgent need for regular environmental monitoring, stricter pollution controls, and improved waste management strategies to protect aquatic ecosystems and human health.