摘要:
全氟化合物(PFASs)作为一类新型的有机污染物，因具有持久性、可长距离传输、生物蓄积性和生物毒性等POPs特性，近年来得到全世界的广泛关注。本文以北京市水源地(密云水库和官厅水库)为研究区域，采用固相萃取(SPE)前处理与高效液相色谱串联质谱联用(HPLC-MS/MS)相结合的方法，分析测定了鱼样品中包括全氟辛烷磺酸(PFOS)、全氟辛酸(PFOA)、全氟丁酸(PFBA)、全氟丁烷磺酸(PFBS)等在内的12种PFASs的含量。利用同位素法确定了不同种类鱼的营养级关系，研究不同营养级中的PFASs浓度及生物放大效应，重点对全氟辛烷磺酸(PFOS)与全氟辛酸(PFOA)的生态风险以及对人体的健康风险进行评价。结果表明：北京市水源地的鱼体中的PFASs存在不同程度的检出，其中，全氟辛烷磺酸(PFOS)、全氟辛酸(PFOA)、全氟壬酸(PFNA)、全氟癸酸(PFDA)、全氟十一酸(PFUdA)和全氟十二酸(PFDoA)的检出率均达到100%，PFASs总量浓度达1.70～14.32 ng·g-1 wet weight (w.w.)，PFOS和长链全氟羧酸PFCAs是鱼体中的主要污染物。同位素鉴定水库鱼的营养级层次范围在2.11～4.10，且肉食性鱼类营养级大多高于杂食性鱼类，PFOS沿着食物链生物放大的过程与稳定碳氮同位素富集过程基本同步。此外，采用人均日摄入量法(average daily intake, ADI)评估得到PFOS与PFOA的风险值分别为1.16 ng·kg-1·d-1和0.31 ng·kg-1·d-1，整体低于人均每天可承受摄入量(tolerable daily intake, TDI)，结果表明，北京水源地鱼体中PFOS和PFOA含量未达到对生态系统和人体健康具有风险的水平。
Abstract:
As emerging persistant organic pollutants (POPs), perfluoroalkyl substances (PFASs) have attracted the worldwide attention due to their persistent, bioaccumulative, toxic and long range transport attributes. In present study, the Miyun Reservoir and Guanting Reservoir were selected as study areas, and the PFASs concentrations in the fish samples from these two drinking water sources of Beijing were detected. Samples were prepared using solid phase extraction (SPE) and analyzed with the high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). A total of 12 PFASs including perfluorobutanoic acid (PFBA), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUdA), perfluorododecanoic acid (PFDoA), perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS) and perfluorooctane sulfonate (PFOS) were quantified. Isotope technology was used to identify the trophic level of different species of fish. Besides, the biomagnifications of different PFASs in fish were explored and the human health risks from PFOS and PFOA contaminants of fish origin were estimated. The results showed that the concentrations of PFASs in fish samples ranged from 1.70 to 14.32 ng·g-1 w.w. (wet weight). PFOS and long-chain perfluorinated carboxylates (PFCAs) including PFOA, PFNA, PFDA, PFUdA and PFDoA were the most frequently detected PFASs, which were detected in all fish samples. Trophic levels of fish in the study areas were in the range of 2.11 to 4.10, and the levels of most carnivorous fish were higher than the omnivorous one. The biomagnifications of PFOS and the enrichment of stable-carbon and nitrogen isotope were basically synchronous. Based on statistics of consumption amount of fish in Beijing, the human daily intake of PFASs were estimated to be 1.16 ng·kg-1·d-1 for PFOS and 0.31 ng·kg-1·d-1 for PFOA, respectively, which were below the human tolerable daily intake (TDI). The current findings indicated that the levels of PFOA and PFOS contamination in water sources of Beijing posed no risk to ecology and human health.
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