Polychlorinated biphenyls in raptor and owl eggs in the Czech Republic

Abstract

In 2001, raptor and owl eggs were collected for the purpose of detection of contamination by poly­chlorinated biphenyls (PCBs) at 15 sites in the southeastern area of the Czech Republic. In total 31 unhatched eggs of 4 raptor species and 3 owl species were examined. PCB determination was carried out by high-resolution gas chromatography. PCB content was expressed in μg per 1 kg of lipid weight for the major PCB congeners 28, 52, 101, 118, 138, 153 and 180, serving as indicators. In all examined eggs the indicator PCB congeners were found. The ranges of total values of indicator PCB congeners found in different raptor and owl species were as follows: kestrel (Falco tinnunculus) 37.0 and 44.3 (n = 2), black kite (Milvus migrans) 28.3–40.5 (n = 3), imperial eagle (Aquila heliaca) 66.4 (n = 1), marsh harrier (Circus aeruginosus) 45.1 (n = 1), barn owl (Tyto alba) 20.6–46.1 (n = 17), long-eared owl (Asio otus) 32.0–41.9 (n = 6) and tawny owl (Strix aluco) 47.5 (n = 1) μg/kg of lipid weight. PCB congener 153 was the one most frequently found.