Department of Aquatic Science and Assessment, Swedish University of Agricultural Sciences (SLU), Uppsala, SE-75007, Sweden.
Department of Aquatic Science and Assessment, Swedish University of Agricultural Sciences (SLU), Uppsala, SE-75007, Sweden; Swedish Geotechnical Institute (SGI), SE-581 93, Linköping, Sweden.
Chemosphere. 2022 May;295:133944. doi: 10.1016/j.chemosphere.2022.133944. Epub 2022 Feb 9.
Per- and polyfluoroalkyl substances (PFAS) are known to be persistent, bioaccumulative, and have adverse health effects, but very little is known about PFAS in the terrestrial environment and factors influencing their distribution. This paper presents one of the first comprehensive studies investigating PFAS (n = 28) in background forest soils (n = 27) on national scale across Sweden. The results showed that 16 of 28 target PFAS were present and all sites contained at least three PFAS compounds, with total concentrations ranging between 0.40 ng/g dry weight (dw) and 6.6 ng/g dw. Perfluorooctanesulfonic acid (PFOS) showed the highest detection frequency of 89% and a median concentration of 0.39 ng/g dw. The PFOS loads (ng/m) showed a distinct spatial distribution, with a significant exponential increase from north to south (R = 0.55; p < 0.001) and west to east (R = 0.35; p < 0.01). In some parts of Sweden, the compound 6:2 fluorotelomer sulfonate (6:2 FTSA) had a higher median concentration (1.4 ng/g dw), but was in comparison to PFOS more impacted by local sources. Partial least squares discriminant analysis (PLS-DA) showed regional clustering of PFAS compositional profiles, indicating that PFAS soil background concentrations are functions of spatial variations at local, regional, and countrywide scale. Such spatial trends have not been observed previously and it could not be deduced whether they are indicative of trends on a global scale, or country-specific and better explained by proximity to densely populated urban areas. An interpolation and extrapolation raster map created from the results was used to calculate the average total PFAS load on Swedish soils. Estimated total load in the top 10-cm soil layer was 2.7 ± 2.4 tons for PFOS and 16 ± 14 tons for ∑PFAS, indicating that soil carries a considerable legacy of past PFAS release.
全氟和多氟烷基物质 (PFAS) 具有持久性、生物累积性和对健康的不良影响，但人们对其在陆地环境中的分布及其影响因素知之甚少。本文介绍了在瑞典全国范围内首次对背景森林土壤中（n=27）的 PFAS 进行的综合研究之一（n=28）。结果表明，在所研究的 28 种目标 PFAS 中，有 16 种存在于所有研究地点，所有地点至少含有三种 PFAS 化合物，总浓度范围为 0.40ng/g 干重 (dw) 至 6.6ng/g dw。全氟辛烷磺酸 (PFOS) 的检出频率最高，为 89%，中位数浓度为 0.39ng/g dw。PFOS 负荷（ng/m）呈现出明显的空间分布，从北到南呈显著指数增长（R=0.55；p<0.001），从西到东呈显著指数增长（R=0.35；p<0.01）。在瑞典的一些地区，6:2 氟代烷氧基苯磺酸盐（6:2 FTSA）的浓度更高（1.4ng/g dw），但与 PFOS 相比，它受局部来源的影响更大。偏最小二乘判别分析（PLS-DA）表明，PFAS 组成谱具有区域聚类，表明 PFAS 土壤背景浓度是局部、区域和全国范围内空间变化的函数。以前没有观察到这种空间趋势，也不能推断它们是否表明全球范围内的趋势，或者是特定于国家的，并且更能解释为靠近人口稠密的城市地区。从结果中创建的插值和外推栅格地图用于计算瑞典土壤中 PFAS 的平均总负荷。估计在表层 10cm 土壤层中 PFOS 的总负荷为 2.7±2.4 吨，∑PFAS 的总负荷为 16±14 吨，表明土壤携带了大量过去 PFAS 释放的残留物。
