Diet and metabolic state are the main factors determining concentrations of perfluoroalkyl substances in female polar bears from Svalbard

• Published in: Environmental pollution (1987) 2017-10, Vol.229, p.146-158
• Main Authors: Tartu, Sabrina, Bourgeon, Sophie, Aars, Jon, Andersen, Magnus, Lone, Karen, Jenssen, Bjørn Munro, Polder, Anuschka, Thiemann, Gregory W., Torget, Vidar, Welker, Jeffrey M., Routti, Heli
• Format: Article
• Language: English
• Subjects: Animals; Arctic Regions; Breeding status; Carbon Isotopes - analysis; Carboxylic Acids; Diet - statistics & numerical data; Ecosystem; Ecotoxicology: 489; Environmental Monitoring; Environmental Pollutants - metabolism; Fasting; Fasting Stable isotope; Fatty Acids; Feeding Behavior; Female; Fluorocarbons - analysis; Fluorocarbons - metabolism; Habitat quality; Ice Cover; Matematikk og Naturvitenskap: 400; Mathematics and natural science: 400; Norway; PFAS; Seasons; Stable isotope; Svalbard; Ursidae - metabolism; Ursus maritimus; VDP; Zoofysiologi og komparativ fysiologi: 483; Zoologiske og botaniske fag: 480; Zoology and botany: 480; Zoophysiology and comparative physiology: 483; Økotoksikologi: 489
• ISSN: 0269-7491; 1873-6424; 1873-6424
• DOI: 10.1016/j.envpol.2017.04.100

Perfluoroalkyl substances (PFASs) have been detected in organisms worldwide, including Polar Regions. The polar bear (Ursus maritimus), the top predator of Arctic marine ecosystems, accumulates high concentrations of PFASs, which may be harmful to their health. The aim of this study was to investigate which factors (habitat quality, season, year, diet, metabolic state [i.e. feeding/fasting], breeding status and age) predict PFAS concentrations in female polar bears captured on Svalbard (Norway). We analysed two perfluoroalkyl sulfonates (PFSAs: PFHxS and PFOS) and C8-C13 perfluoroalkyl carboxylates (PFCAs) in 112 plasma samples obtained in April and September 2012–2013. Nitrogen and carbon stable isotope ratios (δ15N, δ13C) in red blood cells and plasma, and fatty acid profiles in adipose tissue were used as proxies for diet. We determined habitat quality based on movement patterns, capture position and resource selection functions, which are models that predict the probability of use of a resource unit. Plasma urea to creatinine ratios were used as proxies for metabolic state (i.e. feeding or fasting state). Results were obtained from a conditional model averaging of 42 general linear mixed models. Diet was the most important predictor of PFAS concentrations. PFAS concentrations were positively related to trophic level and marine diet input. High PFAS concentrations in females feeding on the eastern part of Svalbard, where the habitat quality was higher than on the western coast, were likely related to diet and possibly to abiotic factors. Concentrations of PFSAs and C8-C10 PFCAs were higher in fasting than in feeding polar bears and PFOS was higher in females with cubs of the year than in solitary females. Our findings suggest that female polar bears that are exposed to the highest levels of PFAS are those 1) feeding on high trophic level sea ice-associated prey, 2) fasting and 3) with small cubs. [Display omitted] •We measured PFASs in plasma of 112 female polar bears from Svalbard.•Diet is the strongest predictor of PFAS concentrations.•Metabolic state determines PFSA and medium chain PFCA concentrations.•Females with cubs of the year had the highest concentrations of PFOS. PFAS concentrations are driven by diet and metabolic state (feeding/fasting) in female polar bears; decreasing sea ice extent is likely to modify PFAS exposure in polar bears.