Factors Influencing Concentrations of PFAS in Drinking Water: Implications for Human Exposure

Per- and polyfluoroalkyl substances (PFAS) are widely used in consumer and industrial products but have subsequently raised concerns about their toxicity. To evaluate factors influencing PFAS concentrations in drinking water and to estimate human exposure, ten PFAS were measured in tap water from the UK and China, also bottled water originating from 15 different countries. In this study, perfluorooctanoic acid and perfluorooctanesulfonate (PFOS) were the most frequently detected (>99%) and dominated in global bottled water, with other PFAS also highly detected (67%-93%). ∑₁₀PFAS concentrations differed significantly in natural mineral vs purified, but not in glass vs plastic and still vs sparkling bottled water. ∑₁₀PFAS concentrations in Chinese tap water (9.2 ng/L) exceeded significantly those in UK tap water (2.7 ng/L). Except for PFOS in Chinese tap water, related target PFAS concentrations in all water samples were well below the reference values. High detection rates of target PFAS in both tap and bottled water highlight necessary for monitoring a wide range of PFAS. Estimated human exposure of target PFAS via drinking water does not appear serious human health risk. Interestingly, boiling and activated carbon filtration can reduce substantially (50%-90%) concentrations of PFAS in water.