A comprehensive review of heavy metal pollution and its biological impact on Clarias batrachus in central India

Abstract

Heavy metal contamination in aquatic ecosystems poses a significant threat to biodiversity, human health, and water quality, particularly in industrial regions such as the Durg-Bhilai area of Chhattisgarh, India. This study compiles and reviews recent findings on the occurrence, bioaccumulation, and ecological impacts of heavy metals—including lead, cadmium, chromium, mercury, and arsenic—focusing on their distribution in water bodies, sediments, and aquatic organisms, with a special emphasis on Clarias batrachus, a freshwater fish species commonly used in biomonitoring. Sources of contamination are largely attributed to untreated industrial effluents, urban runoff, and agricultural discharges. The reviewed literature highlights bioaccumulation in fish tissues and associated biochemical and histopathological alterations, indicating sub-lethal and chronic toxicity. Risk assessments based on metal concentrations in fish muscles reveal potential health hazards for local populations consuming contaminated fish. Studies also suggest seasonal variations in metal concentrations, necessitating continuous monitoring and policy interventions. This review integrates ecotoxicological data with environmental standards set by BIS and WHO to identify critical contamination hotspots and recommend remedial measures. It emphasizes the urgent need for strengthened regulatory frameworks, sustainable waste management, and public awareness to mitigate heavy metal pollution and protect aquatic health in the region.