Legacy and Novel Per- and Polyfluoroalkyl Substances in Surface Soils across China: Source Tracking and Main Drivers for the Spatial Variation

Abstract

China aims to actively control the contamination of globally concerning per- and polyfluoroalkyl substances (PFASs). Evaluation of the current situation can provide a critical reference point for tracking the effectiveness of ongoing progress. Herein, we present the first comprehensive assessment of the spatial variations of 20 legacy and 54 novel PFASs in Chinese background soils in 2021. Novel PFASs were extensively detected in 98.4% of the samples, with 21 species being first reported, which greatly facilitated the appointment of diverse emission sources that aligned with local industrial structures. However, legacy PFASs still dominated the ∑₇₄PFAS profile (median 0.51 ng/g, 0.050–8.33 ng/g). The spatial heterogeneity of soil PFASs was positively driven by economic development and atmospheric deposition, enabling the establishment of predictive models to project the national distribution and temporal trends. Elevated PFAS levels were predominantly distributed in the more industrialized eastern and southern regions, as well as other coastal areas with greater precipitation. ∑₇₄PFAS in surface soils was estimated to increase by 12.9 pg/(g year) over 2002–2021, which would continue alongside economic growth, albeit with greater contributions from novel alternatives. Our work provides comprehensive baseline and predictive data to inform policies toward PFAS control in China.