Biotransformation of fluorotelomer compound to perfluorocarboxylates in humans

Abstract

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/m(3) 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 C(4)-C(18) 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.

Determination of fluorotelomer alcohols in selected consumer products and preliminary investigation of their fate in the indoor environment

“…Intensive research has been conducted to study their sources, fate, transport, and distribution in environmental media, human exposure, and ways to reduce the health risks. Fluorotelomer alcohols (FTOHs) are major precursors of PFCAs and other related compounds because FTOHs can ultimately degrade to form PFCAs through atmospheric oxidation Young and Mabury, 2010) and biodegradation (Nilsson et al, 2013;Butt et al, 2014). In addition, 1H,1H,2H,2H-perfluoro-1-octanol (6:2 FTOH) and 1H,1H,2H,2H-perfluoro-1-decanol (8:2 FTOH) have also been found to be estrogenic (Maras et al, 2006;Liu et al, 2010).…”

6:2 Fluorotelomer iodide in vitro metabolism by rat liver microsomes: Comparison with [1,2-14C] 6:2 fluorotelomer alcohol

“…Other transient metabolites (a-OH 5:3 acid, 5:2 Uacid, and 5:2 Uacid) were only detected sporadically among the different experimental systems at low levels (<0.15 mol% together). 5:3 acid was also detected in serum samples of ski-wax workers exposed to 6:2 FTOH via inhalation (Nilsson et al, 2013).…”

“…[F(CF 2 ) 7 CH 2 CH 2 COOH], and to a less extent PFNA (perfluorononanoic acid) (Martin et al, 2005;Fasano et al, 2006;Nabb et al, 2007;Nilsson et al, 2013). Historically, 5000-6000 t per year equivalent of perfluoroalkyl iodide was manufactured globally between 2000 and 2002 (Prevedouros et al, 2006).…”

Uptake, Translocation, and Metabolism of 8:2 Fluorotelomer Alcohol in Soybean (Glycine max L. Merrill)

“…Much attention has been paid to the metabolism of FTOHs in different biological systems. 4,5,19 However, limited information is available on the metabolic pathways in plants. In this study, phase I and phase II metabolism of 8:2 FTOH in soybean were revealed.…”

“…In the homologous series of FTOHs, 8:2 FTOH has historically been produced in the largest volume. Degradation of 8:2 FTOH by oxidation in the atmosphere, 9,10 photolysis in aqueous environments, 11 aerobic and anaerobic microbial biodegradation in terrestrial environments, 12−14 and in vivo and in vitro metabolism in animals 15−18 and in humans 19,20 has been reported. The 8:2 FTOH degradation in different matrixes shares some common steps, proceeding via saturated and unsaturated fluorotelomer carboxylic acid intermediates, which are finally oxidized to PFCAs as the terminal products.…”