Children exposed to high levels of per‑ and polyfluoroalkyl substances (PFAS) in utero face a significantly higher risk of developing asthma. That’s according to the Swedish paper, “Prenatal Exposure to Per- and Polyfluoroalkyl Substances (PFAS) and Incidence of Asthma and Wheeze in Childhood: A Register-Based Cohort Study in Ronneby, Sweden,” recently published in the journal, PLOS Medicine.
The paper detailed a large population‑based study of 11,488 children born between 2006 and 2013 in Blekinge County, Sweden. It included residents of the city of Ronneby, where drinking water was contaminated for decades by aqueous film‑forming foam (AFFF) used at a nearby military airfield. Children were followed from birth through age 12 or the end of 2022 using national health and prescription registries.
According to researchers, the findings raise new concerns about the long‑term health impacts of PFAS contamination in drinking water, particularly in communities affected by firefighting foam chemicals. The study’s authors noted that children whose mothers lived in areas with very high PFAS contamination during pregnancy had a 44% higher risk of developing asthma compared to children with background‑level exposure. The association was strongest for clinically diagnosed asthma after age three, a period when asthma diagnoses are considered more reliable, researchers said. No significant association was observed between PFAS exposure and early‑childhood wheezing.
A secondary causal analysis estimated that by the end of follow‑up, 26.7% of highly exposed children developed asthma, compared with 16.1% in the background‑exposed group, reinforcing the strength of the association.
Previous studies examining PFAS and asthma have produced mixed results, researchers noted, often due to small sample sizes and exposure levels typical of the general population. The paper’s authors noted that this study was among the first to examine health effects in a highly exposed community, where PFAS concentrations in drinking water exceeded 10,000 ng/L — hundreds of times higher than levels seen in most population studies.
PFAS are known to cross the placenta and accumulate in fetal tissues, including the lungs. According to the study’s authors, experimental research suggests these chemicals may disrupt lung development and immune function during critical developmental windows, potentially increasing asthma risk.
Although the researchers caution that their findings should be replicated in other highly exposed populations, they said the results point to a potentially substantial public health impact of AFFF‑related PFAS contamination. The authors further noted that communities worldwide with known PFAS exposure may face similar long‑term health risks.
