Maternal Exposure to Per- and Polyfluorinated alkyl substances (PFAS) in Drinking Water and Associations with Birth Outcomes

Per- and polyfluoroalkyl substances (PFAS), used in firefighting foam and as water and oil-repellants in nonstick cookware, fabrics and other materials, are widely detected in watersheds across the United States, and globally. Epidemiological studies have found that PFAS are associated with adverse health effects, including thyroid disease, cancer, and adverse birth outcomes. In 2017-2018, high levels of PFAS were detected in both the Haw River and Cape Fear River in North Carolina, raising concerns for potential health effects in towns which draw drinking water from these rivers. This research sought to examine associations between exposure to PFAS (using watershed as a proxy for PFAS exposure) and birth outcomes in NC, focusing specifically on birth weight and gestational age at birth. A multiple linear regression model was used to compare outcomes in eleven regions of NC, defined by their drinking water source. After adjusting for potential confounders and stratifying analyses by infant sex, the largest difference in birth weight was observed in the Headwater of the Cape Fear River (serving the population of Eastern Chatham County and Goldston-Gulf District), where male infants were born 0.26 lbs (± 0.13) lighter on average, and were born 4.72 (± 1.93) days earlier, than the reference group (Falls Lake (Raleigh); p<0.1 for birth weight and p<0.05 for gestational age). Similar patterns were observed in populations drawing water from Lake Mackintosh, Jordan Lake, and the Cape Fear River, whereas no statistically significant differences in birth weight or gestational age were observed in the population drawing water from the Haw River (i.e., the Town of Pittsboro). Overall, the research study concluded that there are spatial differences in adverse birth outcomes across NC, which may be due to exposure to contaminants in water such as PFAS; however, future studies are needed to specially examine PFAS exposures at the individual level.