Environmental Toxicology and Chemistry

To estimate the risk of metal (Cu, Zn, Pb, and Cd) exposure of tree sparrows through food at different life stages (including nestling, juvenile, adult in summer, and adult in winter), metal daily intake (MDI), metal daily intake per unit of body weight (MDIBW), and exposure risks (hazard quotient and hazard index) of tree sparrows at different life stages from a polluted area, Baiyin, and a control area, Liujiaxia, were assessed. Metal daily intakes and MDIBWs of tree sparrows from Baiyin were higher than those from Liujiaxia, which can be attributed to higher metal concentrations of food sources in Baiyin than those in Liujiaxia. Metal daily intakes and MDIBWs of nestlings were higher than those of adults and juveniles. This difference is observed probably because nonphytophagous invertebrates, the predominant food fed to nestlings, possessed the highest metal concentrations. In addition, adults in summer had higher MDIs and MDIBWs than juveniles and adults in winter. This finding is probably observed because juveniles and adults in winter consumed a higher proportion of maize, which had the lowest metal concentrations. In addition, the biomagnification of 4 metals through the food chain increased the health risks of tree sparrows. Exposure risks of tree sparrows to metals were comparable to those of waterfowl and raptors, even when soil metals were below threshold. Environ Toxicol Chem 2019;38:2785–2796. © 2019 SETAC