Monitoring of heavy metal contamination using tissues of two ardeids chicks, Korea

This study presents concentrations of iron, zinc, manganese, lead and cadmium in livers and kidneys of Little Egret Egretta garzetta (n = 10) and Black-crowned Night-Heron Nycticorax nycticorax (n = 10) chicks from Pyeongtaek, Gyeonggi-do, Korea. Essential element concentrations such as iron, zinc and manganese did not differ between both species chicks in livers and kidneys, but lead and cadmium concentrations were significantly greater in both tissues of Little Egret chicks (lead 2.78 +/- 4.06 microg/g wet weight, cadmium 10.3 +/- 12.8 kg/g wet weight) than in those of Black-crowned Night-Heron chicks (lead 0.92 +/- 0.73 microg/g wet weight, cadmium 1.00 +/- 1.00 kg/g wet weight). Lead and cadmium concentrations in livers of Black-crowned Night-Heron chicks were highly related to sediment and/or prey concentrations of their foraging sites in Korean studies. It shows that lead and cadmium concentrations in livers of heron chicks can reflect those of surrounding environment of breeding sites. In this study, cadmium concentrations were higher in kidneys than in livers and it's not recent high-level exposure but chronic background exposure to cadmium contamination around breeding site. Therefore, we suggest that cadmium concentrations in livers and kidneys can be used as a bioindicator of acute and/or chronic local contamination.