Mortality factors and lead contamination of wild birds from Korea.

Wild birds have frequently been found dead in their natural habitats, but little is known about what ecological stressors may impact health of wild populations. Here, we report the potentially harmful lead (Pb) levels in tissues along with necropsies on 69 individuals of cranes, raptors, and waterfowl found dead between 2000 and 2003 in Korea. In all samples diagnosed, trauma (n = 22), severe emaciation (n = 15), and infectious diseases (n = 11) were identified.

Effects of age on heavy metal concentrations of black-crowned night herons Nycticorax nycticorax from Korea.

This study presents concentrations of heavy metals in tissues of Black-crowned night herons (Nycticorax nycticorax), age-related variations related to the growth stage from chicks to adults, and comparison of concentrations between chicks and adults. Heavy metal differences by growth stage from chicks to adults were observed for iron concentrations in the muscle; manganese concentrations in the kidney; zinc and copper concentrations in the muscle; lead concentrations in the liver, kidney, and bone; and cadmium concentrations in the kidney. Comparing chicks with adults, iron concentrations in the kidney and bone of adults were higher than those of chicks.

Abnormal lead exposure in globally threatened Cinereous vultures (Aegypius monachus) wintering in South Korea.

Globally threatened Cinereous vultures (Aegypius monachus) regularly over-winter in South Korea, and they have frequently been found dead in their natural habitats. As one possible factor for their mortality, we investigated tissues for heavy metal contaminants along with necropsies on 20 dead Cinereous vultures. Severe emaciation was found in the survey, being associated with 19 of the deaths.

Possible routes for lead accumulation in feral pigeons (Columba livia).

This study examined possible routes for lead (Pb) accumulation in resident pigeons collected from rural, urban, and four industrial sites in Korea. The accumulation pattern of Pb was comparable to the study sites. The highest Pb concentration was found in the bone, followed by kidney, liver, and lung of pigeons.

Reproductive effects of heavy metal accumulation on breeding feral pigeons (Columba livia).

To investigate the effects of heavy metal accumulations on breeding birds, we compared the egg size, eggshell thickness and some reproductive parameters in feral pigeon populations collected from Seoul and Ansan colonies. The results showed that concentrations of Pb in bone and Cd in kidney of adult pigeons in Seoul were three times higher than in Ansan colony. Significant positive correlation was also observed between Pb and Zn in bone and Cd and Zn in kidney of adult pigeons from Seoul, but not Ansan.

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.

Factors causing variations of lead and cadmium accumulation of feral pigeons (Columba livia).

In order to understand the factors causing variation of lead and cadmium accumulation in tissues of feral pigeons in Seoul and Ansan, Korea, we investigated their age, food items (crop and gizzard contents) as well as environmental factors such as soil, atmosphere, and local traffic density. The results indicate that concentrations of Pb and Cd were highly increased in the order of eggs < chicks < adults. In food analysis, supplementary foods (rice, small stones, domestic scraps, cements, hairs, Styrofoam, etc.

Monitoring for lead pollution using feathers of feral pigeons (Columba livia) from Korea.

We investigated lead exposure conditions using unwashed feathers of feral pigeons as a monitor for lead pollution from rural, central urban, and four industrial complex areas in Korea with different ambient lead concentrations. Overall, the lead levels in the feathers increased when the atmospheric lead levels increased, so that the lead levels in the feathers from urban and industrial areas were two to four times greater than those in the rural area. However, there are no significant differences in the liver lead concentrations between rural and the other areas, suggesting that the lead originated from ingestion are not differences in locations.