Residues of DDT and HCH pesticides in rice samples from different geographical regions of India: a multicentre study.

As part of a multicentre study conducted by the Indian Council of Medical Research, 2000 samples of rice were collected from rural and urban areas of 13 states representing different geographical regions of India. The samples were analyzed for residues of DDT [2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane] and different isomers of HCH [1,2,3,4,5,6-hexachlorocyclohexane, a mixture of isomers] by gas-chromatography. Residues of DDT and HCH, respectively, were detected in about 58 and 73% of the samples analysed. Medians of both DDT and HCH in rice samples were around 0.01 mg kg (-1). Concentrations of alpha-, beta-, gamma- and delta-HCH exceeded a maximum residue limit of 0.05 mg kg (-1) for each isomer in rice fixed by the Ministry of Health and Family Welfare of the Indian Government in 4.3, 2.6, 1.7 and 1.2% of the samples, respectively. There is no statutory limit fixed in India for DDT residues in cereals. Its maximum residue limit of 0.1 mg kg (-1) in cereals recommended by Codex was exceeded by about 2% of the samples examined. Estimated intake of DDT and isomers of HCH through consumption of rice contaminated at their median and 90th percentiles constituted a small proportion of their acceptable daily intakes.