levels of organochlorine pesticide residues in water and sediment from selected agricultural sectors of kanyakumari district, tamil nadu, india

the levels of 19 organochlorine pesticides (ocps) in surface water and under water sedimentsfrom tanks located nearby the prime agricultural areas of kanyakumari district, tamil nadu, india wereinvestigated to evaluate their pollution risks. a total of 36 surface water samples at 9 sampling sites and27 sediment samples at 9 sampling stations were collected from tanks, which were the water sources forcultivation. the total ocps concentration in surface water and sediments were 5.68–25.12 ng/l and 17.7–58.59 ng/g dry weight (dw), respectively. among the ocps, hexachlorocyclohexanes (hchs),dichlorodiphenyltrichloroethane (ddts) and heptachlor epoxide were the most dominant compounds inthe sediment as well as surface water. the dominant ocps in sediment and water were β-hch in hchs,p,p′-ddd in ddts and heptachlor epoxide in other ocps. distribution of hchs, ddts and other ocpswere different indicating their different sources. composition analysis in sediments indicated a recent usage of lindane.