PERSISTENT ORGANOCHLORINE INSECTICIDE RESIDUES IN SOME PADDY, UPLAND AND URBAN SOILS OF INDIA

A wide variety of agricultural soils from different regions of India such as paddy, wheat, mustard, potato, cotton, tea, tomato, sugarcane, grape and urban soils were surveyed for the residual levels of persistent organochlorine insecticide residues in 1988 and 1989. DDT and HCH concentrations were found to be higher in upland soils and lower in paddy field soils. These results indicate the large application of HCH and DDT compounds for agricultural purposes in India. In urban soil DDT levels were higher than HCHs reflecting the use of the former insecticide in relatively large amounts for vector control. Among DDT compounds, p,p'-DDE showed higher percentage in paddy and upland soils. On the other hand, p,p'-DDT contributed to higher levels in urban soils. The beta-HCH was detected as the dominant isomer in both agricultural and non agricultural soils. The levels and percentage compositions of DDTs and HCHs revealed the extent of environmental contamination caused by the continuous usage of persistent organochlorine insecticides in large quantities in tropical areas like India.