State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China.
Environ Sci Technol. 2013 Aug 20;47(16):9249-57. doi: 10.1021/es402120y. Epub 2013 Aug 8.
Short-chain perfluoroalkyl acids (PFAAs), which have less than seven fluorinated carbons, have been introduced as substitutes for eight-carbon homologue products. In this study, water, sediment, and biological samples (fish and plant) were collected from Tangxun Lake, which is located near a production base of the fluorochemical industry in Wuhan, China. Perfluorobutane sulfonate (PFBS) and perfluorobutanoic acid (PFBA) were the predominant PFAAs in surface water, with average concentrations of 3660 ng/L and 4770 ng/L, respectively. However, perfluorooctane sulfonate (PFOS) was the most abundant PFAA in sediments, with an average concentration of 74.4 ng/g dw. The organic carbon normalized distribution coefficients (KOC) indicated that short-chain PFAAs (CF2 < 7) tended to have lower adsorption potentials than PFOS, perfluorooctanoic acid (PFOA), and longer perfluoroalkyl chain compounds. PFBS and PFBA could transport to a farther distance in the horizontal direction along the water flow and infiltrate into deeper depths in the vertical direction. However, levels of PFOS and PFOA in water dropped exponentially along the current, and their proportions were decreased gradually with the increasing depth in sediment cores. Furthermore, values of log bioconcentration factor (BCF) of the short-chain PFAAs were all relatively low (<1), indicating no bioaccumulation potentials for short-chain PFAAs in aquatic species.
短链全氟烷基酸（PFAAs），其含氟碳原子少于七个，已被作为八碳同系物产品的替代品引入。本研究采集了来自中国武汉氟化学工业生产基地附近的汤逊湖的水、沉积物和生物样本（鱼类和植物）。全氟丁烷磺酸（PFBS）和全氟丁酸（PFBA）是地表水中主要的 PFAAs，其平均浓度分别为 3660ng/L 和 4770ng/L。然而，在沉积物中，全氟辛烷磺酸（PFOS）是最丰富的 PFAAs，平均浓度为 74.4ng/g dw。有机碳归一化分配系数（KOC）表明，短链 PFAAs（CF2<7）的吸附潜力低于 PFOS、全氟辛酸（PFOA）和更长的全氟烷基链化合物。PFBS 和 PFBA 可以在水流方向上沿水平方向输送更远的距离，并在垂直方向上渗透到更深的深度。然而，PFOS 和 PFOA 在水中的浓度沿水流呈指数下降，其在沉积物核心中的比例随深度的增加而逐渐降低。此外，短链 PFAAs 的生物浓缩系数（BCF）的对数值均较低（<1），表明短链 PFAAs 在水生生物中没有生物累积潜力。
