Heavy metal contamination in marine fish from the Andaman sea: Influence of habitat and health risk assessment

This study investigates Hg, Cd, Cu, Zn, and Pb concentrations in 324 fish samples from 43 species, including two cephalopod species, in the Andaman Sea. The fish were categorized into pelagic and demersal groups. The findings revealed average heavy metal concentrations in the order: Zn > Cu > Hg > Pb > Cd, with pelagic fish showing higher levels than demersal fish. Certain larger pelagic fish had mercury concentrations above prescribed limits, posing possible health hazards, even though they are less commonly consumed by humans. Cd and Pb levels in certain species exceeded regulatory thresholds of 0.05–1 μg/g and 0.3 μg/g, respectively, while Cu and Zn remained within safe limits. Although the overall cancer risk was low, the Target Hazard Quotient (THQ) and Hazard Index (HI) values surpassed 1, indicating significant health risks from consuming species such as Alopias superciliosus, Isurus oxyrinchus, Lepturacanthus savala, Makaira mazara, and Sphyraena barracuda. These findings underscore the need for ongoing monitoring and public advisories to mitigate health risks. •Pelagic fish showed higher heavy metal levels than demersal fish from Andaman Sea.•Larger fish exhibited significant mercury bioaccumulation compared to smaller fish.•Some large predator species exceeded mercury limits for human consumption.•Lead levels in certain fish surpassed permissible levels, posing health risks.•Recommendations for seafood safety