Accumulation of organochlorine pesticides and polychlorinated biphenyls insediments, aquatic organisms, birds, bird eggs and bat collected from South India

Concentrations of polychlorinated biphenyls (PCBs), DDT and its metabolites (DDTs), HCH isomers (HCHs), chlordane compounds (CHLs) and hexachlorobenze ne (HCB) were determined in sediment, soil, whole body homogenates of resid ent and migratory birds and their prey items (including fish, green mussel, snail, earthworm, crabs, prawn, lizard and frogs), bird eggs and bats coll ected from southern India during 1995 and 1998. Accumulation pattern of org anochlorines (OCs) in biota was, in general, in the order, HCHs > DDTs > PC Bs > CHLs=HCB. Magnitude of OC concentrations increased in the order of sed iments < green mussel < earthworm < frog < lizard < fish < bird egg < bats < birds tissues. Biomagnification features of OCs were examined in resident and migrant birds to evaluate the exposure levels of these chemicals in wi ntering grounds of migrant birds. Accumulation of DDTs in migratory birds d uring wintering in India may be of concern due to the great biomagnificatio n potential of DDTs. Eggs of some resident species contained noticeable con centrations of OCs. Concentrations of OCs in three species of bats analyzed in this study were lower than that found in passerine birds. In addition t o OCs, butyltin compounds were also detected at low concentrations in bats.