Woodard & Curran, 40 Shattuck Road, Andover, MA 01810, United States.
Woodard & Curran, 40 Shattuck Road, Andover, MA 01810, United States.
Sci Total Environ. 2023 Sep 10;890:164051. doi: 10.1016/j.scitotenv.2023.164051. Epub 2023 May 16.
Atmospheric transport and wet deposition have contributed to the worldwide distribution of per- and polyfluoroalkyl substances (PFAS) in terrestrial and aquatic ecosystems, even in remote areas far from known industrial sources. However, little is known regarding the impact of cloud and precipitation formation dynamics on PFAS transport and wet deposition, nor the range of variability in PFAS concentrations within a closely distributed monitoring network. Precipitation samples were collected from a network of 25 stations in a focused geographic region (the Commonwealth of Massachusetts, USA) from stratiform and convective storm systems to evaluate if the different cloud and precipitation formation mechanisms in these two fundamental types of storm systems influenced PFAS concentrations in precipitation, and to assess the range of variability in PFAS concentrations in precipitation at a regional scale. PFAS were detected in 11 of 50 discrete precipitation events. Of the 11 events from which PFAS were detected, 10 of the events were convective in nature. PFAS were detected during only one stratiform event at one station. This suggests that local and regional atmospheric PFAS sources entrained by convection events controls regional atmospheric PFAS flux, and that PFAS flux estimates should consider the type and magnitude of precipitation events. The PFAS detected were primarily perfluorocarboxylic acids, with relatively higher detection frequency for shorter-chained compounds. Compilation of PFAS data from precipitation across primarily the eastern United States, from urban, suburban, and rural areas, including those in industrial areas, indicates population density is a poor predictor of precipitation PFAS concentrations. While the total PFAS concentration in precipitation in some areas exceeds 100 ng/L, the median concentrations across all areas are generally less than about 10 ng/L.
大气输送和湿沉降导致全氟和多氟烷基物质 (PFAS) 在陆地和水生生态系统中的分布遍及全球，甚至在远离已知工业源的偏远地区也是如此。然而，人们对于云形成和降水形成动力学对 PFAS 输送和湿沉降的影响，以及在紧密分布的监测网络中 PFAS 浓度的变化范围知之甚少。从层状和对流风暴系统中收集了来自马萨诸塞州（美国）一个重点地理区域的 25 个站点的降水样本，以评估这两种基本类型的风暴系统中的不同云形成和降水形成机制是否会影响降水的 PFAS 浓度，并评估在区域尺度上降水的 PFAS 浓度的变化范围。在 50 次离散降水事件中，有 11 次检测到了 PFAS。在检测到 PFAS 的 11 次事件中，有 10 次事件是对流性质的。仅在一个站点的一个层状事件中检测到 PFAS。这表明，对流事件夹带的局部和区域大气 PFAS 源控制着区域大气 PFAS 通量，并且 PFAS 通量估计应考虑降水事件的类型和规模。检测到的 PFAS 主要是全氟羧酸，短链化合物的检测频率相对较高。来自主要是美国东部、城市、郊区和农村地区（包括工业区）的降水的 PFAS 数据汇编表明，人口密度是降水 PFAS 浓度的一个很差的预测因子。虽然一些地区的降水总 PFAS 浓度超过 100ng/L，但所有地区的中位数浓度通常小于约 10ng/L。
