Occurrence and tissue distribution of 33 legacy and novel per- and polyfluoroalkyl substances (PFASs) in Baikal seals (Phoca sibirica)

• Published in: The Science of the total environment Vol. 889; p. 164096
• Main Authors: Sait, Shannen T.L., Rinø, Silje F., Gonzalez, Susana V., Pastukhov, Mikhail V., Poletaeva, Vera I., Farkas, Julia, Jenssen, Bjørn M., Ciesielski, Tomasz M., Asimakopoulos, Alexandros G.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-09-2023
• Subjects: Aquatic biota; Lake Baikal; Marine mammals; Perfluorochemicals (PFCs); Pinnipeds; Polyfluorinated substances; Wildlife; Perfluorochemicals (PFCs); Lake Baikal; Wildlife; Aquatic biota; Pinnipeds; Polyfluorinated substances; Marine mammals
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.164096

Per- and polyfluoroalkyl substances (PFASs) are bioaccumulative and associated with adverse effects in both wildlife and humans. The occurrence of 33 PFASs was assessed in the plasma, liver, blubber, and brain of 18 Baikal seals (Phoca sibirica) (16 pups and 2 adult females) from Lake Baikal, Russia (in 2011). Of the 33 congeners analysed for: perfluorooctanosulfonic acid (PFOS), 7 long chain perfluoroalkyl carboxylic acids (C8–C14 PFCAs) and 1 branched PFCA (perfluoro-3,7-dimethyloctanoic acid; P37DMOA) were most frequently detected. The PFASs in plasma and liver with the highest median concentrations were legacy congeners: perfluoroundecanoic acid (PFUnA; plasma: 11.2 ng/g w.w.; liver: 7.36 ng/g w.w.), PFOS (plasma: 8.67 ng/g w.w.; liver: 9.86 ng/g w.w.), perfluorodecanoic acid (PFDA; plasma: 5.13 ng/g w.w.; liver: 6.69 ng/g w.w.), perfluorononanoic acid (PFNA; plasma: 4.65 ng/g w.w.; liver: 5.83 ng/g w.w.) and perfluorotridecanoic acid (PFTriDA; plasma: 4.29 ng/g w.w.; liver: 2.55 ng/g w.w.). PFASs were detected in the brain of Baikal seals, indicating that PFASs cross through the blood–brain barrier. In blubber, the majority of PFASs were detected in low abundance and concentrations. In contrast to legacy PFASs, novel congeners (e.g., Gen X) were either detected infrequently or not found in Baikal seals. The worldwide occurrence of PFASs in pinnipeds was compared and lower median concentrations of PFOS were observed in Baikal seals relative to other pinnipeds. Conversely, similar concentrations of long chain PFCAs were found in Baikal seals compared to other pinnipeds. Furthermore, human exposure was assessed by estimating weekly intakes (EWI) of PFASs through Baikal seal consumption. Although PFASs concentrations were comparatively low relative to other pinnipeds, consumption of Baikal seal could exceed current regulatory guidelines.
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•PFASs found in plasma, liver, blubber, and brain of Baikal seals.•PFASs in suckling and pre-weaned Baikal seal pups demonstrated maternal transfer.•PFOS and long chain PFCAs demonstrated highest concentrations in plasma and liver.•Novel PFASs were either infrequently detected or not found in Baikal seals.•Human consumption of Baikal seal liver and muscle can exceed current regulatory guidelines for specific PFASs.