Abstract:
Organochlorine pesticides (OCPs) have been beneficial to man and environment but their inadvertent use
has caused considerable harm to human health. Despite the proliferation of different types of pesticides,
organochlorines such as HCH and DDT still account for two third of the total consumption in India
because of their low cost and versatility in action again various pests. Since, Assam, a state in North-eastern
part of India is an endemic area with perennial transmission where mosquito borne diseases are serious
health problems; these pesticides are still being used in huge quantities in vector control as well as in
agriculture. A total of 331 human blood samples were collected from district Nagaon and Dibrugarh of
Assam to determine the residue levels of DDT and HCH in human blood. The concentrations of selected
persistent organochlorine pollutants were measured with gas chromatography-electron capture detector.
The results demonstrated that the mean levels of total DDT and HCH were 743 lg L 1 and 627 lg L 1 for
district Nagaon while 417 lg L 1 and 348 lg L 1 for district Dibrugarh. The difference of total HCH and
total DDT between these two districts was found to be highly significant (P < 0.0001). Among DDT metabolites,
the same trend was observed for both the districts as p,p-DDT was the principal component contributed
41% for Nagaon and 58% for Dibrugarh. In case of HCH residues, for Nagaon, b-HCH was the
predominant contaminant comprised more than 34% while for Dibrugarh, it was a-HCH that was contributing
43% of total HCH concentration.
