SHORT RESEARCH AND DISCUSSION ARTICLE Beavers indicate metal pollution away from industrial centers in northeastern Poland

Abstract Heavy metals are persistent environmental contam-inants, and wild animals are increasingly exposed to the harmful effects of compounds of anthropogenic origin, even in areas distant from industrial centers. We used atomic ab-sorption spectrometry to determine levels of cadmium (Cd), lead (Pb), copper (Cu), and zinc (Zn) in liver and kidney of wild Eurasian beavers (Castor fiber) in Poland. Cd concen-trations in liver (0.21±0.44 μg/g) and in kidney (2.81± 4.52 μg/g) were lower in juvenile than in adult beavers. Pb concentrations in liver (0.08±0.03 μg/g) and kidney (0.08± 0.03 μg/g) were similar among all individuals, while both Cu and Zn levels were higher in liver (Cu 9.2±4.5 μg/g; Zn 35.7 ±3.5 μg/g) than in kidney (Cu 3.7±1.1 μg/g; Zn 21.5±2.7 μg/ g). Cu levels also differed between juveniles and adults. We reviewed the literature reporting metal concentrations in bea-vers. Our results indicate metal contamination in beavers away from important industrial emission sources and suggest the natural environment should be regularly monitored to ensure their levels are below recommended, legal values