Organochlorine pesticides and polychlorinated biphenyls in various tissues of waterbirds in Nalabana bird sanctuary, Chilika Lake, Orissa, India.

In order to understand whether organochlorine pesticides and polychlorinated biphenyls (PCBs) are responsible for the mortality of waterbirds in Nalaban bird sanctuary in Chilika Lake, the current investigation was carried out in tissues of 11 individuals comprising 7 species of birds. One or more residues were detected in all the tissues of birds analysed. Concentration of ∑HCH, ∑DDT, and ∑PCBs were ranged from below detectable level (BDL)-811 ng/g, BDL-1,987 ng/g and BDL-1,027 ng/g respectively. PCBs levels were less than the food and drug administration's (FDA) action limits. Although varying levels of residues were detected among tissues, they do not appear to be responsible for the mass mortality of waterfowl. However, the need for additional research is heightened when considering that some of the birds are classified as a globally protected species by the international bodies.