Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, College of Environmental Science and Engineering, Nankai University , Tianjin 300071, P.R. China.
Environ Sci Technol. 2013 Sep 17;47(18):10619-27. doi: 10.1021/es401905e. Epub 2013 Aug 27.
Perfluoroalkyl acids (PFAAs) are persistent and bioaccumulative compounds that have been associated with adverse health outcomes. In human blood, PFAAs exist as both linear and branched isomers, yet for most linear homologues, and for all branched isomers, elimination rates are unknown. Paired blood and urine samples (n = 86) were collected from adults in China. They were analyzed by a sensitive isomer-specific method that permitted the detection of many PFAAs in human urine for the first time. For all PFAAs except perfluoroundecanoate (PFUnA), levels in urine correlated positively with levels in blood. Perfluoroalkyl carboxylates (PFCAs) were excreted more efficiently than perfluoroalkane sulfonates (PFSAs) of the same carbon chain-length. In general, shorter PFCAs were excreted more efficiently than longer ones, but for PFSAs, perfluorooctanesulfonate (PFOS, a C8 compound) was excreted more efficiently than perfluorohexanesulfonate (PFHxS, a C6 compound). Among PFOS and perfluorooctanoate (PFOA) isomers, major branched isomers were more efficiently excreted than the corresponding linear isomer. A one-compartment model was used to estimate the biological elimination half-lives of PFAAs. Among all PFAAs, the estimated arithmetic mean elimination half-lives ranged from 0.5 ± 0.1 years (for one branched PFOA isomer, 5m-PFOA) to 90 ± 11 years (for one branched PFOS isomer, 1m-PFOS). Urinary excretion was the major elimination route for short PFCAs (C ≤ 8), but for longer PFCAs, PFOS and PFHxS, other routes of excretion likely contribute to overall elimination. Urinary concentrations are good biomarkers of the internal dose, and this less invasive strategy can therefore be used in future epidemiological and biomonitoring studies. The very long half-lives of long-chain PFCAs, PFHxS, and PFOS isomers in humans stress the importance of global and domestic exposure mitigation strategies.
全氟烷基酸（PFAAs）是持久性和生物累积性化合物，与不良健康结果有关。在人体血液中，PFAAs 既存在于直链异构体中，也存在于支链异构体中，但对于大多数直链同系物和所有支链异构体，消除率尚不清楚。从中国成年人中采集了配对的血液和尿液样本（n = 86）。 采用一种灵敏的同分异构体特异性方法对其进行了分析，该方法首次允许首次在人体尿液中检测到许多 PFAAs。对于除全氟十一酸（PFUnA）以外的所有 PFAAs，尿液中的水平与血液中的水平呈正相关。 具有相同碳链长度的全氟烷基羧酸（PFCAs）比全氟烷磺酸（PFSAs）的排泄效率更高。 通常，较短的 PFCAs 的排泄效率高于较长的 PFCAs，但对于 PFSAs，全氟辛烷磺酸（PFOS，C8 化合物）的排泄效率高于全氟己烷磺酸（PFHxS，C6 化合物）。 在 PFOS 和全氟辛酸（PFOA）异构体中，主要支链异构体的排泄效率高于相应的直链异构体。 使用单室模型估计 PFAAs 的生物消除半衰期。 在所有 PFAAs 中，估计的算术平均消除半衰期范围从 0.5 ± 0.1 年（一个支链 PFOA 异构体 5m-PFOA）到 90 ± 11 年（一个支链 PFOS 异构体 1m-PFOS）。 尿液排泄是短 PFCAs（C ≤ 8）的主要消除途径，但对于较长的 PFCAs、PFOS 和 PFHxS，其他排泄途径可能有助于整体消除。 尿液浓度是内部剂量的良好生物标志物，因此这种侵入性较小的策略可用于未来的流行病学和生物监测研究。 长链 PFCAs、PFHxS 和 PFOS 异构体在人体内的半衰期非常长，这强调了全球和国内暴露缓解策略的重要性。
