Division of Analytical & Environmental Toxicology, Department of Laboratory Medicine & Pathology, University of Alberta, Edmonton T6G 2G3, Alberta, Canada.
Norwegian Institute for Air Research, Hjalmar Johansens gt. 14, Tromsø NO-9296, Norway.
Environ Int. 2015 Feb;75:215-22. doi: 10.1016/j.envint.2014.11.014. Epub 2014 Dec 6.
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.
人体全氟辛烷磺酸 (PFOS) 负荷归因于直接 PFOS 和间接 PFOS 前体 (PreFOS) 暴露。这两种途径的相对重要性已经被估计，但 PFOS 和 PreFOS 暴露的相对时间轨迹尚未被研究。在这里，我们分析了美国成年人（1974-2010 年）的存档血清样本和瑞典初产妇（1996-2010 年）的混合样本中两种假设的 PreFOS 暴露生物标志物，即 PFOS 异构体谱（用支链 PFOS 的百分比，%br-PFOS 表示）和手性 1m-PFOS 对映体分数（1m-PFOS EF）。在对潜在混杂因素进行校正后，在美国样本和瑞典样本中，1996-2000 年期间观察到 %br-PFOS 和 1m-PFOS EF 之间存在显著相关性，支持 %br-PFOS 和 1m-PFOS EF 都是 PreFOS 暴露的生物标志物的假设。在瑞典样本中，从 2000 年到 2010 年，%br-PFOS 呈上升趋势，从 1996 年到 2000 年，1m-PFOS EF 呈非对映体比例增加的趋势。在美国样本中，未观察到 %br-PFOS 或 1m-PFOS EF 的统计学显著趋势，但美国男性的 %br-PFOS 明显高于女性，1m-PFOS EF 明显低于女性（即更多的非对映体），而且在年龄较大的组中也显示出类似的显著差异，与年龄较小的组相比。%br-PFOS 和 1m-PFOS EF 的这些时间趋势不容易解释，结果强调了人类接触 PFOS 的不确定性。
