Per- and polyfluoroalkyl substances (PFASs) are positively associated with thyroid hormones in an arctic seabird

By Amalie Vigdel Ask, Bjørn Munro Jenssen, Sabrina Tartu, Frédéric Angelier, Olivier Chastel, and Geir Wing Gabrielsen
Environ Toxicol Chem
January 5, 2021
DOI: 10.1002/etc.4978

Per- and polyfluoroalkyl substances (PFASs) are associated with several disrupted physiological and endocrine parameters. Regarding endocrine mechanisms, laboratory studies suggest that PFASs could disrupt the thyroid hormone (TH) system and alter circulating TH concentrations. THs play a ubiquitous role-controlling thermoregulation, metabolism, and reproduction. However, evidence for disruption of THs by PFASs remain scarce in wildlife. This study aimed to investigate the associations between concentrations of PFASs, THs, and body condition (BC) in an arctic seabird, the black-legged kittiwake (Rissa tridactyla). We collected blood from kittiwakes sampled in Svalbard (2013 and 2014). Plasma samples were analyzed for total thyroxine (TT4) and total triiodothyronine (TT3) concentrations; detected PFASs included branched (br) and linear (lin) C perfluoroalkyl sulfonates (PFSAs, i.e., PFOS) and C -C perfluoroalkyl carboxylates (PFCAs). The dominant PFASs in the kittiwakes were linPFOS and C -and-C -PFCAs. Generally, male kittiwakes had higher concentrations of PFASs than females. We observed positive correlations between linPFOS, C -PFCA, and TT4 in males, whereas in females C -PFCAs were positively correlated to TT3. Interestingly, we observed contrasted correlations between PFASs and BC; the direction of the relationship was sex dependent. Although these results show relationships between PFASs and circulating TH concentrations in kittiwakes, the study design does not allow for concluding on causal relationships related to effects of PFASs on the TH system. Future experimental research is required to quantify this impact of PFASs on the biology of kittiwakes. The apparently different association among PFASs and BC for males and females are puzzling and more research is required. This article is protected by copyright. All rights reserved.

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