Heavy Metal Distribution in Chicks of Two Heron Species from Korea

This study presents concentrations of iron, manganese, zinc, copper, lead, and cadmium in tissues of black-crowned night heron (Nycticorax nycticorax) (n = 8) and grey heron (Ardea cinerea) (n = 9) chicks from Pyeongtaek heronry, Gyeonggi-do, Korea, 2001. Iron (respectively, 45.8 ± 24.0 μg/wet g, 155 ± 123 μg/wet g), zinc (38.3 ± 5.34 μg/wet g, 50.9 ± 14.0 μg/wet g), and copper (9.93 ± 2.26 μg/wet g, 30.2 ± 12.9 μg/wet g) concentrations in feathers, manganese concentrations in livers (3.26 ± 0.68 μg/ wet g, 1.50 ± 0.58 μg/wet g), kidneys (1.43 ± 0.27 μg/wet g, 0.84 ± 0.34 μg/wet g), and bones (1.34 ± 0.50 μg/wet g, 3.17 ± 1.31 μg/wet g) were different between black-crowned night heron and grey heron chicks. Lead concentrations in bones (0.11 ± 0.04 μg/wet g, 0.61 ± 0.42 μg/wet g) and cadmium concentrations in liver (13.5 ± 2.30 μg/wet kg, 10.3 ± 1.59 μg/wet kg), kidney (6.61 ± 2.54 μg/wet kg, 2.31 ± 1.29 μg/wet kg), and muscle (5.25 ± 5.91 μg/wet kg, 1.37 ± 0.90 μg/wet kg) differed between chicks of the two heron species. The differences of heavy metal concentrations in tissues in herons and egrets were reported to other similar studies. Heavy metal concentrations for both heron species were at background levels. In both species, lead concentrations were higher in livers than in bones and cadmium concentrations were higher in livers than in kidneys. We suggest that it is not chronic exposure but acute exposure to lead and cadmium contamination around breeding site that leads to these observations. Therefore, lead and cadmium concentrations in tissues can be used as a bioindicator of acute local contamination.