Identification, characterization, and human health risk assessment of perfluorinated compounds in groundwater from a suburb of Tianjin, China

Abstract

This study investigated the occurrence of perfluorinated compounds (PFCs) in groundwater from 16 sampled wells for the public drinking water supply in a suburb of Tianjin, China. Thirteen PFC analytes were quantified by ultra-high performance liquid chromatography/electrospray tandem mass spectrometry. Concentrations of the total PFCs in groundwater ranged from 0.32 to 8.3 ng L−1 with an average of 2.4 ng L−1. The dominant PFCs were perfluorobutane sulfonic acid (PFBS) and perfluorooctanoic acid (PFOA) with averages of 1.1 and 0.81 ng L−1, respectively. Levels of perfluorocarboxylic acids containing 6–12 carbon atoms (except PFOA) in groundwater decreased with the increase of their carbon chain lengths. Strong positive correlations were observed between perfluoroheptanoic acid (PFHpA) and PFOA, PFHpA and perfluorononanoic acid (PFNA), PFHpA and PFBS, and PFOA and PFNA (Spearman Correlation test, p < 0.01), suggesting that these chemicals might originate from the same or similar pollution sources. The principal component analysis–multiple linear regression model analysis showed that PFCs mainly came from the fluorotelomer production and emission, followed by the introduction of the substitute compounds. PFC concentrations were positively correlated to the contents of dissolved organic carbon and Mn2+, and negatively correlated to the contents of total nitrogen and SO4 2− in groundwater. These indicated that PFC distributions and pollution levels in groundwater were related to organic carbon, nutrients and inorganic salts. The preliminary health risk assessment suggested that there was no significantly immediate harm of exposure to PFCs in drinking water for the villagers in the suburb of Tianjin, China.