| Sumario: | In recent years, per- and polyfluoroalkyl substances (PFASs) have received increasing public attention due to their persistence, bioaccumulation potential and toxicity to humans and wildlife. PFASs are widely used in various products including surfactants in paper, textiles, and aqueous film forming foams (AFFFs). The application of PFAS-containing AFFFs has been linked to the contamination of the aqueous environment with PFASs. The leaching of PFASs from PFAS contaminated soil to groundwater may also affect drinking water quality, which in turn may be a possible exposure source for humans. This study focused on i) the occurence of 26 individual PFASs in soil and groundwater, ii) their mobility and transport in different compartments including soil, sediment, groundwater, surface water and drinking water, and iii) identification of their source by comparing their composition profiles. Samples were collected in soil (n=12), sediment (n=2), groundwater (n=28), surface water (n=6) and drinking water (n=4) in Uppsala and in the nearby area in May/June 2014. The sampling sites included three fire fighting training sites, the first was located in the north part of Uppsala (Fire fighting facility 1), the second was located in the east part of Uppsala (Fire fighting facility 2), and the third was located close to the city centre of Uppsala (Fire fighting facility 3). In the soil and sediment, the dominant PFASs were perfluorooctane sulfonate (PFOS; 81% of the ∑PFASs) and perfluorooctanesulfonamide (FOSA; 5%), and the highest concentrations were detected at Fire fighting facility 2 (∑PFASs = 608 ng g-1 dry weight (dw)), while the maximum ∑PFAS concentrations at Fire fighting facility 1 and 3 were 139 ng g-1 dw and 3 ng g-1 dw, respectively. In groundwater along Uppsalaåsen (i.e. groundwater flow from north to south in Uppsala), were the dominant PFASs perfluorohexane sulfonate (PFHxS; 54%), PFOS (13%) and perfluorobutane sulfonate (PFBS; 11%) while at Fire fighting facility 2, located on the east side of Uppsalaåsen, the dominant PFASs were 6:2 fluorotelomer sulfonate (6:2 FTSA; 51%), PFOS (20%) and perfluorohexanoate (PFHxA; 8%). Fire fighting facility 2 had the highest detected concentrations in groundwater (∑PFASs = 8015 ng L-1) and groundwater near Fire fighting facility 1 had the second highest (∑PFASs = 1000 ng L-1). The concentration along the groundwater flow decreases towards the south of Uppsala. In the river water samples, PFOS (47%), PFHxS (41%), PFHxA (7%) and PFPeA (3%) has been detected with ∑PFASs ranging between below the detection limit and 15 ng L-1. In contrast, much higher ∑PFAS concentrations were found in surface water at a pond at Fire fighting facility 2 with 3026 ng L-1. The ∑PFAS concentrations in drinking water in Uppsala were generally low ranging between 1 ng L-1 and 8 ng L-1. The dominant PFASs in drinking water were PFHxS (73%) and PFBS (17%). A Principal Component Analysis (PCA) was performed for the PFAS pattern in the groundwater samples. The PCA showed that the PFAS pattern at Fire fighting facility 2 did not correspond with the PFAS pattern at Uppsalaåsen (the groundwater flow from north to south) which indicates that Fire fighting facility 2 is not connected to Uppsalaåsen. It is important to note that this study was a one-time grab sampling campaign and all values should be interpreted with care. More detailed studies are needed to verify the spatial distribution of PFASs in soil and groundwater, vertical and horizontal transport of PFASs in soil and groundwater, and seasonal and long-term changes of the PFAS contamination in the environment.
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