Concentrations of per- and polyfluoroalkyl substances (PFAS) in paired tap water and blood samples during pregnancy

Per- and polyfluoroalkyl substances (PFAS) are water-soluble chemicals of concern due to their persistence, ubiquity, and toxicity. We explored correlations between drinking water and blood PFAS levels in a subset of the mother-child Barcelona Life Study Cohort (BiSC), Barcelona, Spain (2021). For 105 study participants, we analyzed 35 PFAS in tap water (unfiltered and filtered) and 23 PFAS in 98 paired plasma samples during the 3rd trimester, using LC-MS/MS. Water consumption habits were ascertained at the third trimester through questionnaires. The majority of participants consumed bottled water (56.2%), 5/35 PFAS were detected in unfiltered tap water, 4/35 PFAS in activated carbon filtered tap water samples, and 14/23 PFAS in plasma samples. Our results showed that PFHpA at the observed concentrations in drinking water was significantly correlated with paired plasma levels ( R = 0.2; p = 0.04). Impact statement Exposure to PFAS is an emerging public health concern. Our manuscript contributes meaningful information from a subset of the mother-child Barcelona Life Study Cohort (BiSC), reporting levels of a wide range of PFAS in paired tap water and plasma samples from a sensitive subpopulation residing away from point source contamination. Our findings draw attention to low-exposure ranges of PFAS in drinking water, and a weak but significant water-plasma correlation for PFHpA (a PFOA homologue), suggesting that drinking water can be a contributor to human exposure to PFHpA.