Assessment of heavy metal and health risk to humans from fin fishes from the coastal regions of Tamil Nadu, Bay of Bengal, India

This study evaluates the concentrations, bioaccumulation patterns, and potential human health risks of heavy metals, lead (Pb), zinc (Zn), copper (Cu), and iron (Fe) in commercially important finfish and associated sediments from four strategic coastal sites (Kasimedu, Uppanar, Mallipattinam, and Velankanni) along the Bay of Bengal, Tamil Nadu, India. Metal levels were quantified using atomic absorption spectrophotometry (AAS), revealing the order Fe > Zn > Pb > Cu across all sites. The bioaccumulation factor (BAF) for Zn exceeded safety limits in all regions, indicating high biotic uptake, while hierarchical cluster analysis (HCA) confirmed Pb as the major contaminant linked to anthropogenic sources. The hazard index (HI) exceeded the safe threshold (HI > 1) in all stations, with the highest value observed at Mallipattinam (HI = 3.48), suggesting potential non-carcinogenic risks for regular consumers. This work represents the first comparative multi-site assessment integrating sediment–fish metal relationships with bioaccumulation and health risk indices for the Tamil Nadu coast. The findings provide baseline data for regional pollution monitoring and highlight the urgent need for remediation measures to ensure seafood safety and protect coastal communities dependent on marine resources.