Residential history and drinking water type as predictors of serum PFAS in communities with a history of contaminated drinking water.

backgroundDrinking water is a major source of per- and polyfluoroalkyl substance (PFAS) exposure in contaminated communities. Even after mitigation, residents may still have elevated serum PFAS levels; however, duration of elevated body burdens and influence of drinking water type (unfiltered tap, filtered tap, bottled) are poorly characterized.

objectiveEvaluate associations of residential history and drinking water type with serum PFAS among individuals living in communities with historical drinking water contamination.

methodsThe Massachusetts (MA) PFAS & Your Health Study is part of the PFAS Multi-site Study, a cross-sectional epidemiological study in eight U.S. states. In 2021-2023, we collected blood and questionnaire data from 673 adults in Hyannis and Ayer, MA, where public water systems were historically contaminated by PFAS mainly from aqueous film-forming foam (AFFF). We analyzed residential histories for 399 participants and calculated time lived in these communities between 2000 and major PFAS mitigation by public water supplies in 2016 (Hyannis) and 2018 (Ayer). We used multivariable linear regression to examine associations of time lived in study area and drinking water type with serum perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA), controlling for age and sex.

resultsMedian serum PFOS and PFHxS concentrations were 2.1-2.8 times higher in Hyannis than Ayer, consistent with higher historical PFAS concentrations in Hyannis water. In both communities, time lived in study area was associated with higher serum PFOS and PFHxS. In Hyannis, long-term residents ( > 16 years) had 2.3 times higher PFHxS and 1.4 times higher PFOS than short-term residents ( < 5 years). Filtered tap or bottled water was associated with lower serum PFAS compared to unfiltered tap water in Hyannis but not in Ayer. SIGNIFICANCE: Actions to reduce exposures from drinking water in contaminated communities can lead to lower serum PFAS levels years later. IMPACT STATEMENT: PFAS exposure from drinking water affects millions of U.S. residents. In this cross-sectional study, we found that residents of communities with contaminated drinking water had elevated serum PFAS levels, particularly long-term residents, even when mitigation of PFAS in public water supplies occurred years prior. Additionally, we found that exposure reductions from drinking filtered tap or bottled water, compared to unfiltered tap water, were reflected in serum PFAS levels. Our findings suggest that addressing PFAS exposures from drinking water, both at the municipal and household level, may reduce cumulative PFAS body burden and thus reduce risk of related health effects.