Unidentified fluorine and TFA dominate the fluorine mass balance in European drinking water
A comprehensive fluorine mass balance analysis of tap water from 34 European cities reveals that while regulated PFAS like PFOA and PFOS are ubiquitous and TFA is the most abundant compound, unidentified extractable fluorine constitutes the majority of the fluorine mass, indicating that current monitoring frameworks significantly underestimate exposure and toxicological risks.