Under the lead of dr. Maja Lazarus and her team from the Institute for Medical Research and Occupational Health (Zagreb, Croatia), we investigated the level of five non-essential metal(loid)s (As, Cd, Hg, Tl, Pb) and nine essential metals (Mg, Ca, Mn, Fe, Co, Cu, Zn, Se, Mo) in hair and blood samples of captive and free-ranging European brown bears collected in Croatia and Poland. Metal(loid) associations with biomarkers of oxidative stress (superoxide dismutase, SOD; glutathione-peroxidase, GSH-Px; malondialdehyde, MDA), as well as metal exposure (metallothionein, MT) were estimated. Lead was the most abundant non-essential metal(loid) in both blood and hair, with four of 35 individuals having blood levels over 100 μg/L. A positive association was found between Pb level and SOD activity in blood. With increasing age, animals showed lower levels of SOD activity and certain essential metals. In general, females had higher SOD activity and blood levels of some essential metals than males. The established metal(loid) baseline values will enable future risk assessment in both captive and wild European brown bear populations.
The study also contributed from our collaborators from the Faculty of Veterinary Medicine, University of Zagreb, Ruđer Bošković Institute in Zagreb, Tatra National Park and the Institute of Environmental Biology of the University of Wrocław.
You can read the paper here https://doi.org/10.1016/j.envres.2020.109166