PFAS in drinking water, wastewater and surface water in Reykjavik, Iceland.

Per- and polyfluoroalkyl substances (PFAS) are persistent contaminants with global environmental and health implications. This study evaluated PFAS concentrations in drinking water, wastewater, and surface water in Reykjavik, Iceland, focusing on seasonal variability and potential pollution sources. Thirty-three samples from groundwater, wastewater, and surface water were analysed for up to 54 PFAS. Results reveal that PFAS concentrations in Reykjavik's drinking water were minimal, which most compounds below detection limits, and the sum of 18 PFAS below 0.5 ng L. These levels were significantly below EU Drinking Water Directive and European Food Safety Authority health limits, indicating effective source water protection. In contrast, elevated PFAS levels were detected in wastewater and surface water, with concentrations reaching 14 ng L for sum 18 PFAS. The most prevalent compound was perfluorobutanoic acid (PFBA). The highest contamination occurred at firefighting training sites, particularly at Reykjavik Airport, where PFAS concentrations exceeded 2000 ng L, dominated by PFOS. A comparison to prior results implied an about 10-fold decrease of PFOS in Reykjavik's wastewater treatment plant since 2017. These findings emphasize the need for continued monitoring, and further investigation into historical and active contamination sources to safeguard environmental and public health in Iceland. Given the presence of PFAS-contaminated sites in Iceland, targeted PFAS management strategies are needed to prevent contamination of drinking water resources.