A national-scale preliminary overview study of poly- and perfluoroalkyl substances (PFAS) occurrence in aquatic environments of England, UK

Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) are emerging contaminants, where some are known to harm ecological and human health. Due to their widespread use, PFAS have become commonly detected in aquatic environments, which serve both as pathways and as reservoirs for these pollutants. This study provides the first full quantitative national overview of 41 PFAS compounds in English waterbodies (surface water, groundwater, coastal, and estuarine; n = 850), using High-Performance Liquid Chromatography-Triple Quadrupole Mass Spectrometry (HPLC-QQQ). Individual PFAS concentrations at 475 sites ranged from 0.0052 to 480 ng/L while ΣPFAS concentrations per site ranged from 0.024 to 2021 ng/L. Monitoring detected the highest concentrations near large distinct urban areas, though PFAS were also present in rural and undeveloped regions, highlighting the importance of detections across different land use. PFOA was one of the most frequently detected PFAS across all waterbodies, consistent with other studies. No clear correlations were found between PFAS physiochemical properties (chain length and functional group) and concentrations, this may be due to the sampling approach focused which focused on an assessment of background concentrations, rather than point-source, pollution. However, shorter chain PFAS compounds dominated detections in surface waters compared to groundwater. Physical properties and PFAS exposure in waterbodies may play a large role in PFAS detections, as higher concentrations were found in surface water relative to groundwater. Future research should explore PFAS trends over time, consider groundwater sampling depths, examine a broader range of land uses, and assess transboundary PFAS transport to better understand PFAS flux in aquatic systems.