Monitoring for Pb and Cd pollution using feral pigeons in rural, urban, and industrial environments of Korea

This study was aimed at evaluating the lead (Pb) and cadmium (Cd) contamination status using resident pigeons from rural (island), central urban (Seoul), and four industrial complex areas in Korea with varying traffic density as well as atmospheric metal pollution records. We also discussed the results with respect to metal exposure trends in urban area after introduction of lead-free gasoline in Korea. Mean concentrations of Pb and Cd in bone and kidney of pigeons from Seoul were comparable to those from industrial complex areas and were about 15-20 times those at the reference site. This suggests that exposure to metals in the urban environment is as high as in the industrial areas. Lead and Cd concentrations in lungs of pigeons from Seoul were significantly higher by more than three times in 2000 than in 1991 (p < 0.01), whereas the residues in liver, kidney, and bone remained at a similar level, despite the introduction of unleaded gasoline in 1993. The Pb and Cd concentrations in tissues of pigeons did not decrease as atmospheric metal levels decreased. Ingestion may be more important than inhalation in exposing pigeons to Pb and Cd in this study.