title: Temporal trends of perfluorooctanesulfonate isomer and enantiomer patterns in archived Swedish and American serum samples.
abstract: Human perfluorooctanesulfonate (PFOS) body burdens are attributable to both direct PFOS and indirect PFOS precursor (PreFOS) exposure. The relative importance of these two pathways has been estimated, but the relative temporal trajectory of exposure to PFOS and PreFOS has not been examined. Here, two hypothesized biomarkers of PreFOS exposure, PFOS isomer profiles (quantified as percent branched PFOS, %br-PFOS) and chiral 1m-PFOS enantiomer fractions (1m-PFOS EF) were analyzed in archived human serum samples of individual American adults (1974-2010) and pooled samples of Swedish primiparous women (1996-2010). After correcting for potential confounders, significant correlations between %br-PFOS and 1m-PFOS EFs were observed in American samples and in Swedish samples for the 1996-2000 period, supporting the hypothesis that both %br-PFOS and 1m-PFOS EF are biomarkers of PreFOS exposure. Significant trends of increasing %br-PFOS, from 2000 to 2010, and increasingly non-racemic 1m-PFOS EFs, from 1996 to 2000, were detected in Swedish samples. No statistically significant trend for %br-PFOS or 1m-PFOS EF was observed in American samples, but American males had significantly higher %br-PFOS and significantly lower 1m-PFOS EF (i.e. more non-racemic) than females, and a similar significant difference was shown in the older age group, relative to the younger age group. These temporal trends in %br-PFOS and 1m-PFOS EF are not easily explained and the results highlight uncertainties about how humans are exposed to PFOS.
authors.affiliation: Division of Analytical & Environmental Toxicology, Department of Laboratory Medicine & Pathology, University of Alberta, Edmonton T6G 2G3, Alberta, Canada.
authors.forename: Yanna
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Division of Analytical & Environmental Toxicology, Department of Laboratory Medicine & Pathology, University of Alberta, Edmonton T6G 2G3, Alberta, Canada.
authors.forename: Alberto S
authors.initials: AS
authors.lastname: Pereira
authors.affiliation: Division of Analytical & Environmental Toxicology, Department of Laboratory Medicine & Pathology, University of Alberta, Edmonton T6G 2G3, Alberta, Canada.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Beesoon
authors.affiliation: Norwegian Institute for Air Research, Hjalmar Johansens gt. 14, Tromsø NO-9296, Norway.
authors.forename: Robin
authors.initials: R
authors.lastname: Vestergren
authors.affiliation: Department of Applied Environmental Science, Stockholm University, Stockholm SE-106 91, Sweden.
authors.forename: Urs
authors.initials: U
authors.lastname: Berger
authors.affiliation: 3M Company, Medical Department, St. Paul 55144, MN, USA.
authors.forename: Geary W
authors.initials: GW
authors.lastname: Olsen
authors.affiliation: Department of Risk and Benefit Assessment, National Food Agency, Uppsala SE-751 26, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Glynn
authors.affiliation: Division of Analytical & Environmental Toxicology, Department of Laboratory Medicine & Pathology, University of Alberta, Edmonton T6G 2G3, Alberta, Canada. Electronic address: jon.martin@ualberta.ca.
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Martin
mesh_terms: D000328:Adult; D017738:Alkanesulfonic Acids / Q000097:blood* / Q000737:chemistry; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000097:blood* / Q000737:chemistry; D005260:Female; D005466:Fluorocarbons / Q000097:blood* / Q000737:chemistry; D006801:Humans; D007536:Isomerism; D008297:Male; D008875:Middle Aged; D013548:Sweden; D014481:United States
chemical_list: D017738:Alkanesulfonic Acids; D004785:Environmental Pollutants; D005466:Fluorocarbons; C076994:perfluorooctane sulfonic acid
keywords: Enantiomers; Human exposure; Isomers; Perfluorooctanesulfonate (PFOS); Perfluorooctanesulfonate precursors (PreFOS); Temporal trends