Temporal trends and sediment-water partitioning of per- and polyfluoroalkyl substances (PFAS) in lake sediment

The use of per- and polyfluoroalkyl substances (PFAS) containing aqueous film forming foams (AFFF) at fire training facilities can have an adverse impact on the surrounding environment. The aim of the present study was to study the distribution and temporal trend of 26 PFAS in water and sediment cores for a lake and a pond affected by AFFF release from a fire training facility in Lulea, northern Sweden. In the aqueous phase, maximum Sigma PFAS concentration was 1.700 +/- 90 ng L-1. Dominant PFAS groups were perfluoroalkane sulfonates (PFSAs) with 70% of the Sigma PFAS, followed by perfluoroalkyl carboxylates (PFCAs, 29%), whereas the contribution of 6:2 fluorotelomer carboxylate (FTSAs) was low (<1%). In the sediment core samples, PFAS concentrations ranged between <1 mu g kg(-1) dry weight (dw) and 76 mu g kg(-1) dw, where perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS) had an average contribution of similar to 71% and similar to 23% of the Sigma PFAS. The sediment core analysis indicated that the PFAS contamination began about 1994 and the highest accumulation rate was observed for the period 2003-2009. The PFAS flux increased from 2.3 mu g m(-2) yr(-1) dw in 1994 to 12 mu g m(-2) yr(-1) dw by 2009. Over the accumulation period 1994-2009, the lake sediment surface received 213 mu g m(-2) dw for Sigma PFAS, where PFOS contributed with 125 mu g m(-2) yr(-1) dw and PFHxS with 65 mu g m(-2) dw. Results point to that sediment cores collected near PFAS hotspot areas can be used as a contamination record to reconstruct release history. (C) 2019 Elsevier Ltd. All rights reserved.