Biotransformation of fluorotelomer compound to perfluorocarboxylates in humans

Levels of perfluorocarboxylates (PFCAs) in biological compartments have been known for some time but their transport routes and distribution patterns are not properly elucidated. The opinions diverge whether the exposure of the general population occurs indirect through precursors or direct via PFCAs. Previous results showed that ski wax technicians are exposed to levels up to 92 000 ng/m3 of 8:2 fluorotelomer alcohol (FTOH) via air and have elevated blood levels of PFCAs. Blood samples were collected in 2007–2011 and analyzed for C4–C18 PFCAs, 6:2, 8:2 and 10:2 unsaturated fluorotelomer acids (FTUCAs) and 3:3, 5:3 and 7:3 fluorotelomer acids (FTCAs) using UPLC–MS/MS. Perfluorooctanoic acid (PFOA) was detected in levels ranging from 1.90 to 628 ng/mL whole blood (wb). Metabolic intermediates 5:3 and 7:3 FTCA were detected in all samples at levels up to 6.1 and 3.9 ng/mL wb. 6:2, 8:2 and 10:2 FTUCAs showed maximum levels of 0.07, 0.64 and 0.11 ng/mL wb. Also, for the first time levels of PFHxDA and PFOcDA were detected in the human blood at mean concentrations up to 4.22 ng/mL wb and 4.25 ng/mL wb respectively.The aim of this study was to determine concentrations of PFCAs and FTOH metabolites in blood from ski wax technicians.

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► The study describes the PFAS blood levels of an occupationally exposed group of ski wax technicians.
► Very high blood levels of PFOA in the blood after exposure to extremely high levels of FTOHs in air.
► Novel finding of metabolic intermediates FTCAs and FTUCAs in blood indicating FTOH metabolisation to PFCAs in humans.
► Novel finding of PFHxDA and PFOcDA in human blood.