Spatial distribution and seasonal variation of pesticide residues in the sediment, seawater, and edible seaweeds: Environmental and human health risk assessment.

This study evaluates the distribution of pesticide residues (PRs) and assesses the ecological and human health risks posed by them from seawater, sediment and edible seaweeds in the Gulf of Mannar. Results showed that hexachlorocyclohexane, heptachlor, aldrin, endrin and endosulfan were the predominant PRs. The maximum concentration of PRs was observed in the monsoon and post-monsoon seasons. Their concentrations in sediment exceeded interim sediment quality guidelines, indicating significant risks to benthic organisms. Except for endrin, the presence of other organochlorine pesticides (OCPs) was below the maximum residual limit. Human health risk assessment revealed that the estimated daily intake of PRs through seaweeds was below the acceptable daily intake. The hazard quotient and hazard ratio were <1, implying that the study seaweeds do not pose significant health risks. The presence of endrin in edible seaweeds, however, indicates safety concerns for consumers and the continued use of banned OCPs in agriculture.