The study, co-authored by Thilo Hofmann and Martin Stockhausen, presents a pan-European assessment of per- and polyfluoroalkyl substances (PFAS) in rivers using harmonised monitoring combined with advanced statistical modelling. Seven high priority PFAS were analysed at hundreds of sites across almost one hundred rivers in over thirty European countries, capturing the footprint of several hundred million people. At least one PFAS was found at almost all monitoring locations, with elevated concentrations in parts of southern, southeastern, and western Europe. These higher levels were linked to nearby landfills, wastewater discharges, and industrial activity, underlining the role of human pressure on river quality.
Seasonal differences showed higher PFAS concentrations in summer, which likely reflects reduced dilution under lower flow conditions. Using partial least squares path modelling, the authors demonstrated that PFAS levels are systematically associated with both socioeconomic pressures and environmental conditions. Among socioeconomic indicators, the Human Footprint Index showed the strongest link to contamination, while electrical conductivity was the environmental factor most closely related to PFAS concentrations, probably because it traces shared transport pathways with wastewater and industrial effluents. A screening level comparison with existing regulatory thresholds indicated that PFAS concentrations at well over half of the monitored sites may be of concern, supporting the use of combined human pressure and hydrochemical indicators to guide more targeted, risk based monitoring and regulatory prioritisation at large scales.
In addition to Thilo Hofmann and Martin Stockhausen from the Centre for Microbiology and Environmental Systems Science (CeMESS), Department of Environmental Geosciences (EDGE), University of Vienna, this pan-continental study represents a major collaborative effort of 53 research groups, bringing together experts from across Europe and beyond, and was led by Jun Li and Alistair Boxall from the Department of Environment and Geography, University of York.
