Levels, spatial distribution and isomer profiles of perfluoroalkyl acids in soil, groundwater and tap water around a manufactory in China

Abstract

In this study, 32 surface soil samples, 24 groundwater samples, and 6 tap water samples were collected around a perfluorosulfonates (PFSAs) manufactory in China to analyze the distributions of perfluoroalkyl acids (PFAAs) including linear and branched isomers. The total concentrations of PFAAs (∑PFAAs) ranged from 1.30 to 913 ng/g on a dry weight basis (dw), 31.4-15656 ng/L, and 11.8-59.7 ng/L in soil, groundwater and tap water samples respectively. Perfluorooctanesulfonate (PFOS) and perfluorobutanoic acid (PFBA) were the predominant PFAAs in the soil whereas PFBA was the predominant congener in groundwater. PFAA concentrations in the soil and groundwater decreased with increasing distance from the manufactory. Shorter-chain PFAAs showed higher proportions in groundwater than in soil samples and that shorter-chain PFAAs exhibited faster decreasing rates in soil samples, which may be due to the differences in the polarity and hydrophobicity of these molecules. For isomer profiles, n-PFHxS, n-PFOS, and n-PFOA were the main isomer in soil samples and groundwater samples. Direct exposure to PFOS and PFOA via the soil and tap water posed relatively low risk to the residents' health.

Keywords: Groundwater; Health risk; Isomer profiles; PFAAs; Soil; Tap water.