Organochlorine Pesticide and Polychlorinated Biphenyl in Feathers of Resident and Migratory Birds of South-West Iran

Abstract

Persistent organochlorine pesticides (OCPs), such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), alpha-, beta-, and gamma-hexachlorocyclohexane (HCH) isomers, together with polychlorinated biphenyl (PCB) congeners (IUPAC Nos. 28, 52, 101, 138, 153, and 180) were determined in tail feathers from 35 birds belonging to 15 species, all originating from the southwest of Iran (Khuzestan, coast of the Persian Gulf) and kept in museum collections. The patterns of organochlorine contaminants (OCs) in birds varied depending on their migratory behavior. Resident birds contained higher median PCB concentrations (<LOQ-151 ng/g feather) than HCHs, DDTs, and HCB. Locally migrating birds had higher median concentrations of HCHs (19-83 ng/g feather). In contrast, long-distance migrants had lower concentrations of HCB and HCHs. A positive correlation was observed among OCs in these birds, suggesting that trophic level, feeding strategy, and taxonomic group are influencing factors for the OC concentrations in bird feathers. An estimate of the risk associated suggests that levels of OCPs and PCBs were lower or close to the threshold reported to affect reproduction in 1990s.