Risk assessment of organochlorine pesticides in seaweeds along the Gulf of Mannar, Southeast India

Bioaccumulation of organochlorine pesticides (OCPs) in red, green, and brown seaweeds from the Gulf of Mannar was investigated using gas chromatography–mass spectrometry (GC–MS). The concentration of OCPs in all the seaweeds was in the order of endosulfan > endrin > HCH > DDT > aldrin > heptachlor > methoxychlor. The concentrations of HCH, endrin, endosulfan, and DDT in Sargassum wightii and Gelidiella acerosa, and HCH and endosulfan in Gracilaria verrucosa were above the limits prescribed by the European Commission. However, in Ulva lactuca, except for endosulfan, all other OCPs were below the permissible level. The bioaccumulation of OCPs in seaweeds was in the order of S. wightii > G. acerosa > Gracilaria verrucosa > U. lactuca. The results of comparative analysis of the levels of the investigated pesticides against the standard human health risk assessment revealed that pesticide exposure from seaweeds is hazardous to human health and the marine environment of the Gulf of Mannar. •Among the different seaweeds, brown seaweed S. wightii is a suitable species for studying the bioaccumulation of pesticides•TThe conc. of all OCPs in S. wightii, G. verrucosa, and G. acerosa were above the MRL prescribed by the EU regulation•U. lactuca accumulates very low pesticide compared to brown and red seaweeds.