Organochlorine residues in odontocete species from the southeast coast of India

Blubber from bottle-nose dolphins, spinner dolphins, humpback dolphin ( Tursiops truncatus, Stenella longirostris and Sousa chinensis) were collected from the Bay of Bengal (southeast coast of India) and analyzed for the organochlorine pesticides hexachlorocyclohexane (HCHs), p, p′-dichlorodiphenyl trichloroethane (DDTs), and polychlorinated biphenyls (PCBs). All nine specimens analyzed contained considerable levels of all the three chemical classes where DDT was in the range of 3330–23 330 ng/g; HCHs in the range of 95–765 ng/g; and PCBs in the range of 210–1220 ng/g (wet weight basis). The reasons for this and the variations in the isomer pattern of HCHs and DDT and its metabolites in marine mammal tissues are discussed.