Human exposure to PFASs in a contaminated area: associations between water and serum levels

Per- and poly- fluorinated substances (PFASs) are industrial chemicals which may exert toxic effects on humans. Widespread use, environmental mobility and persistence enabled these substances to spread and accumulate in the environment. In this paper, we investigated the determinants of human exposure in a hotspot area characterized by PFAS water contamination. The area covers approximately 600 km² and is inhabited by about 150000 people. We examined the relationship between water and serum PFAS concentrations. We estimated PFAS weekly intakes, serum to public drinking water ratios, and clearance factors, and analysed the influence of individual characteristics of participants in PFAS elimination. Our results confirmed that water was a major source of PFAS exposure in the study area. For most participants, weekly PFAS intakes from water exceeded the tolerable weekly intake set by the European Food Safety Authority. Median serum to public drinking water ratios ranged from 5.3 to 1086 for the considered PFASs. Clearance rates were lower in males than in females, even after accounting for potential confounding factors. This sex difference in clearance rates supports the hypothesis that lower PFAS levels in females may be due to faster elimination. Our findings contribute to a better understanding of human exposure to PFASs through water and can support the refinement of prevention and remediation strategies.