全氟烷基羧酸前体物氟调醇的污染水平与生物转化研究进展

全氟烷基羧酸(perfluorocarboxylic acids, PFCAs)普遍具有环境持久性、生物富集性及生物毒性效应.随着政府和国际组织对PFCAs生产和排放的监控和管制,探究PFCAs的间接来源变得愈加迫切.氟调醇(fluorotelomer alcohols, FTOHs)是生产含氟聚合物和含氟表面活性剂的重要原材料,被广泛应用于消费品与工业产品的生产.此外,FTOHs也是多种氟调类产品降解转化过程的主要中间体.FTOHs的降解已被普遍认为是环境和生物体中PFCAs重要的间接来源.FTOHs进入环境后可进行长距离迁移,并且能够在环境介质和生物体内不断转化,生成一系列多氟类中间物质,最终转化生成不同链长的PFCAs.近期研究发现,FTOHs的多氟类中间代谢物表现出比PFCAs更强的生物毒性效应.因此,只有全面了解FTOHs的污染水平与生物转化过程,才能正确评估FTOHs暴露的环境和健康风险.本文全面介绍了FTOHs的理化性质与环境中的来源,概述了FTOHs的分析方法和环境污染状况,分析了FTOHs在不同生物介质中的转化过程,并解析了FTOHs的致毒机制.

Environmental occurrence and biotransformation of perfluoroalkyl carboxylic acid precursors: Fluorotelomer alcohols

Perfluorocarboxylic acids(PFCAs) have received great regulatory attention from the government and international organizations due to their environmental persistence, bioaccumulation and potential toxicity. With the effective reduction of their production and emission in recent years, exploring the indirect sources of PFCAs has become increasingly important. Fluorotelomer alcohols(FTOHs) are important raw materials used to produce fluoropolymers and fluorosurfactants, which have been incorporated into a variety of consumer and industrial products. Moreover, FTOHs are also primary biotransformation intermediates of multiple fluorotelomer-based substances. Degradation of FTOHs has been widely considered as an additional source of PFCAs in the environment and biological species. After entering the environment, FTOHs can undergo long-range transport and can be transformed into polyfluorinated intermediates, and finally oxidized to different carbon-chain lengths of PFCAs. Recent studies also showed that polyfluorinated intermediate metabolites of FTOHs exhibited higher biotoxicity than PFCAs. Therefore, to accurately reveal the environmental and health risks of FTOHs, it is essential to understand their environmental levels and biotransformation routes. In this paper, the sources and physicochemical properties of FTOHs were introduced, the analytical methods and environmental occurrence of FTOHs were reviewed, and the biotransformation processes and toxic mechanisms of FTOHs were analyzed.