Persistent organic pollutants (POPs) are a group of chemicals of global importance. They are resistant to degradation and persist in the environment for a very long time, which is why they are also sometimes referred to as “perennial chemicals.” POPs can be carried over long distances by air and water, so they are distributed in all elements of the environment and can be detected in places where their sources have never been used. Lipophilic (having an affinity for fats) POPs accumulate in the adipose tissue of wild animals and humans, causing adverse health effects on fat metabolism, reproductive, neuroendocrine and immune systems, among others. Our colleagues at the Institute for Medical Research and Occupational Safety and the Faculty of Veterinary Medicine in Zagreb, in collaboration with Dr. Agnieszka Sergiel, analyzed two classes of contaminants in the adipose tissue of male brown bears from the Dinara-Pindos population collected in 2021 and 2022. In addition to the seven indicator polychlorinated biphenyls (PCBs), seven polybrominated diphenyl ethers (PBDEs) were also analyzed. This research is the first on the levels and profile of PBDEs in this species in Croatia, but also in Europe. Although PCBs were banned decades before PBDEs, they were detected at higher concentrations than PBDEs in brown bear tissues, confirming their ubiquity and higher bioaccumulation potential. Overall, the levels of POPs analyzed in this study were relatively low, as expected given that, in its Croatian part, the population under study occupies relatively sparsely populated mountainous regions characterized by low industrial activity, and therefore habitats without significant sources of POP contamination. Nevertheless, the presence of PCBs and PBDEs in the tissues of bears living in such areas confirms their persistence and ability to be transported and deposited over long distances, requiring regular and continuous monitoring of their levels and the levels of their hydroxylated metabolites in the environment. The results presented in the publication can serve as a reference for more contaminated areas and other bear populations in Europe and around the world. More information on this study can be found here.
by Agnieszka Sergiel