Complex monitoring of perfluoroalkyl substances (PFAS) from tap drinking water in the Czech Republic.

This study aims to quantify perfluoroalkyl substances (PFAS) in tap drinking water in the Czech Republic and to assess potential health risks to consumers using hazard ratios. A total of 192 samples (collected systematically throughout the country in 2021) were analysed for 28 PFAS using ultra-performance liquid chromatography with tandem mass spectrometry after solid phase extraction. Total PFAS (∑PFAS) concentrations ranged from undetectable to 23.9 ng/L. Long-chain PFAS (≥7 CF2 groups) were detected less frequently and at lower concentrations compared to short-chain (< 6 CF2 groups) homologues. Detectability and ∑PFAS concentrations in surface and combined water sources (median 2.97 ng/L) samples were higher than in groundwater sources (median 0.48 ng/L). With regard to the new Drinking Water Directive (EU 2020/2184), the parameter "sum of PFAS", defined as the sum of 20 selected PFAS, was five times lower than the minimum acceptable dose in the most contaminated sample. The occurrence of PFAS in the Czech Republic is thus very low and comparable to other recent European studies. Consumption of any of the tested waters would not pose a moderate risk for adults, and only about 1% of the samples could pose a potential health risk.