Spatial and Temporal Analysis of PFAS Contamination in the Fyris River, Uppsala : Concentration, Composition and Point Source Influence

Sammanfattning

Per- and polyfluoroalkyl substances (PFAS) are highly persistent environmental contaminants with widespread distribution and potential health risks. This study examines the spatial distribution, composition, temporal trends, and mass flow of PFAS in surface water along the Fyris River in Uppsala, Sweden, using compiled data from ten studies conducted between 2013 and 2023. Concentration and composition were assessed across six Sites, with a focus on the influence of two known point sources: the Ärna military base and the Kungsängsverket wastewater treatment plant (WWTP). Elevated PFAS levels were observed downstream of both sources, with PFOS concentrations frequently exceeding the EU Environmental Quality Standard for surface water (0.65 ng/L). While PFAS-4 concentrations were also elevated, they were compared against the Swedish drinking water guideline of 4 ng/L as a contextual reference rather than a formal threshold for surface water. Temporal analysis revealed statistically significant decreases in PFAS concentrations and mass flow after 2018 at several Sites, likely reflecting the effects of regulatory measures and voluntary phase-outs. However, concentrations of PFOS and PFAS-4 remained above reference levels post-2018, highlighting the persistence of these substances and the need for continued monitoring and mitigation.