乌梁素海流域地表水中全氟化合物分布、来源及其生态风险

全氟化合物（polyfluoroalkyl substances，PFASs）在长期生产和使用过程中会通过多介质扩散和远距离迁移等方式进入环境中.本研究分析了乌梁素海流域丰水期及枯水期采集的地表水样品中17种PFASs，探讨了该地区PFASs的时空分布特征、潜在来源及生态风险.结果表明，PFASs在所有地表水样品中均有检出，浓度范围为4.00~263.45 ng·L^-1；研究区地表水中PFASs空间分布格局受当地人类活动影响明显，在空间上表现为两个主要特征：一是PFASs浓度较低的黄河水和干渠水，以全氟丁酸（PFBA）为主要组分；二为接纳了河套灌区的工业、农业和生活等废水的总排干水和湖区水，PFASs浓度较高并以全氟辛酸（PFOA）为主要组分.受到短链PFASs产量增加与引黄河水量变化影响，枯水期水样中PFASs含量较高于丰水期的样品.PFOS/PFOA、PFOA/PFNA和PFHpA/PFOA结果表明，研究区PFASs为大气沉降与点源污染混合来源.风险评价结果显示，研究区目前PFOA与全氟辛基磺酸（PFOS）的风险值均较低，但由于全氟化合物的累积特性和长距离传输能力，其长期的累积效应依然不容忽视.

Distribution, Sources, and Ecological Risks of Polyfluoroalkyl Substances in the Surface Water of the Wuliangsuhai Watershed

Polyfluoroalkyl substances (PFASs) enter the environment through multi-media diffusion and long-distance migration during the long-term manufacture and use of products containing PFASs. This study analyzed 17 PFASs in surface water samples collected from the Wuliangsuhai watershed in the wet and dry seasons, and investigated the temporal and spatial distribution characteristics, potential sources, and ecological risks of PFASs in the study area. PFASs were detected in all surface water samples at concentrations ranging from 4.00 to 263.45 ng·L^-1. The spatial distribution of PFASs was affected by local human activities and showed two main types of characteristics. The first type was associated with Yellow River and canal water, which had relatively low concentrations of PFASs and was dominated by perfluorobutanoic acid (PFBA). The second type was associated with drain and lake water receiving industrial, agricultural, and domestic wastewater from the Hetao irrigation area, which had relatively high levels of PFASs and was dominated by perfluorooctanoic acid (PFOA). The PFAS concentrations in water samples collected during the dry season were higher than those collected in the wet season, being affected by the increased production of short-chain PFASs and seasonal changes in the amount of water from the Yellow River. The results of PFOS/PFOA, PFOA/PFNA, and PFHpA/PFOA indicated that the PFASs in the study area originate from atmospheric deposition and point source pollution. The risk assessment results showed that the current risk level from PFOA and PFOS in the study area is relatively low but their long-term cumulative effects cannot be ignored due to the cumulative characteristics and long-distance migration ability of PFASs.