Organochlorine pesticide residues in some Indian wild birds.

Residues of BHC and DDT were estimated by gas-liquid chromatographic analysis of the internal body organs, depot fat, and blood plasma of a few species of Indian wild birds, captured in and around the urban area of Lucknow. Total BHC and gamma-BHC (lindane) levels were high in breast muscle, liver, heart, and lung tissues of pigeon, crow, and vulture, compared with the respective tissues of chicken, cattle egret, and kite. More lindane and total BHC was found in tissues of vulture compared with other species. The major part of BHC isomers in the brain of birds examined was accounted for by alpha-BHC. Total BHC detected in depot fat of crows was 29.7 ppm; lesser amounts were found in vulture, kite, and cattle egret, respectively. Total DDT levels were comparable in the blood plasma of chicken, pigeon, crow, and cattle egret, although residues generally showed the following order in the tissues examined: chicken less than pigeon less than cattle egret less than crow less than kite less than vulture. High levels of DDT were detected in depot fat of crow, kite, and vulture (50.8, 67.0 and 95.3 ppm, respectively). Avian species thus reflect biological magnification of BHC and DDT residues, presumably due to their food habits.