REGIONAL VERSUS LOCAL VARIATIONS OF DDTs, HCHs, HCB, CHLORDANES AND ENDOSULFANS IN THE ATMOSPHERE OF COASTAL AND INLAND CITIES OF INDIA

摘要

India is an agrarian country with massive production and ongoing use of organochlorine pesticides (OCPs) for both agriculture and vector control. But data on regional variations and local distributions are exiguous. Concurrently active (diurnal) and passive air sampling (PAS) was therefore conducted between Dec'3rd 2006- Mar'24th 2007 in four metropolitan cities located in the north (New Delhi), east (Kolkata), west (Mumbai) and south (Chennai) of India. Active air sampling (diurnal) was also conducted in Bangalore, Agra, and Goa. The average AAS data and the PAS data at the similar sampling site for individual OCPs were within a factor of 1-3. Paired T-test analysis shows significantly pronounced regional variation compared to minor local variation of OCPs. The dominance of γ-HCH reflects the substantial use of lindane except in Kolkata where high α-HCH might be due to technical HCH usage. Significant correlation between TC and CC (p<0.0001) in AAS/PAS datasets suggests the ongoing usage of chlordane in India. Elevated α/β-endosulfan ratio in AAS/PAS data from southern India suggests recent use of endosulfan. Higher p,p'-DDE+p,p'-DDD/p,p'-DDT ratio and decreasing TC/CC ratio from southern to northern India reflects substantial weathering of DDT and degradation of cis-chlordane with the decreasing latitude.