直接暴露及前驱物间接暴露对人体中全氟辛酸和全氟辛烷磺酸负荷的相对贡献研究

As a result of their historical production and use in many consumer and industrial applications, perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) are among the most prominent xenobiotics detected in humans. Two general routes of exposure are involved in the burden of PFOA(S) in human body. The first is direct exposure to PFOA(S) via multiple exposure sources including diet, water, dust and air, the second is exposure to PFOA(S)-precursors, and their subsequent biotransformation to PFOA(S), which is called as indirect exposure. The relative magnitude by which either of these two routes contributes to the overall PFOA(S) body burden remains unclear today. The objectives of this study are to investigate the body burden of PFOA(S) including isomers in typical urban population in China and the contamination levels and characteristics of PFOA(S) and their precursors in exposure source matrices in China. Then, with the aid of animal experiments, the two exposure assessment models based on total daily intake or isomeric profiling technique would be improved or optimized. At last, we would estimate the contribution of direct and indirect (via precursor) exposure to the burden of PFOA (S) in humans using the two modeling approaches. The research results of this project will lay theoretical basis for human risk assessment of perfluorinated substances and also provide scientific evidences for environmental management of PFOA(S) and their precursors.

由于大量生产与应用于消费品及工业生产中，全氟辛酸(PFOA)和全氟辛烷磺酸(PFOS)在世界各国人体样品中广泛检出，对人类健康产生潜在危害。人体PFOA(S)既可以来自于环境中PFOA(S)的直接暴露，也可以来自于前驱物的暴露，继而经人体内转化而形成，后者称为间接暴露。然而，这两种暴露模式对人体PFOA(S)负荷的相对贡献，目前尚不明确。本研究拟以PFOA(S)及其前驱物为研究对象，系统调查我国典型城市人群及暴露源介质中的PFOA(S)及其前驱物的种类、水平及异构体组成；并结合动物试验，优化现有的基于每日摄入量的暴露评估模型，重点改进我们先前提出的基于异构体指纹特征的暴露评估模型；在此基础上，运用所建模型评估上述两种暴露模式对人体PFOA(S)负荷的相对贡献，为全氟化合物的人体健康风险评估及相关环境污染控制管理工作提供科学依据。

由于大量生产并使用于消费品及工业生产，全氟辛酸(PFOA)和全氟辛烷磺酸(PFOS)在世界各国人体样品中广泛检出，对人类健康产生潜在危害。人体PFOA(S)既可以来自于环境中PFOA(S)的直接暴露，也可以来自于其前驱物的暴露，继而经体内转化变为PFOA(S)，后者特称为间接暴露。然而，这两种暴露模式对人体PFOA(S)负荷的相对贡献，目前尚不明确，尚缺乏有效的定量方法来评估。本研究以PFOA(S)及其前驱物的水平以及异构体比例为研究对象，在相关目标物的异构指纹分析方法学的基础上，调查了我国城市普通人群及典型工业园区周边人群及其相应暴露源介质中的PFOA(S)及其前驱物的种类、水平及异构体组成。结合动物试验，建立了每日摄入量与内暴露水平的关联模型，在此基础上，重点构建了基以异构体指纹特征的评估模型，以及基以碱性过硫酸盐氧化体系间接分析前驱物量的总氧化分析技术（TOP）等两种评估相对暴露贡献的方法。采用所构建的评估模型和方法，估算了上述两种暴露模式对人体PFOS负荷的相对贡献，研究最终揭示前驱物间接暴露的相对人体贡献在20-50%。因此，本研究对于人体负荷全氟化合物的人体健康风险评估提供了分析、评估等两方面的方法学支撑和科学判定的理论依据。