Children whose mothers were exposed to very high levels of PFAS—so called “forever chemicals”—during pregnancy had a substantially higher incidence of clinically diagnosed asthma.
RT’s Three Key Takeaways:
- Prenatal Exposure Risk: A study of children in Sweden suggests that high prenatal exposure to perfluoroalkyl substances (PFAS) is associated with a higher incidence of asthma in childhood.
- Dose-Response Relationship: The association between PFAS and asthma was observed only at very high exposure levels, potentially explaining why previous studies involving lower background levels produced mixed results.
- Respiratory Health Implications: Findings from communities with contaminated water sources indicate that high environmental exposure to synthetic chemicals may have lasting consequences for pediatric respiratory health.
High prenatal exposure to perfluoroalkyl substances (PFAS) may increase the risk of childhood asthma, according to a study published in PLOS Medicine.
According to the EPA, PFAS (per- and polyfluoroalkyl substances) are widely used, long lasting chemicals, components of which break down very slowly over time. Many PFAS are found in the blood of people and animals all over the world and are present at low levels in a variety of food products and in the environment, including water, air, fish, and soil.
According to researchers, PFAS impact the immune system and are thought to play a role in the development of asthma.
Researchers from Lund University in Sweden analyzed a register-based cohort of children born between 2006 and 2013 in Blekinge County. The study focused on Ronneby, a city where a municipal waterworks had been contaminated with PFAS for decades, resulting in exposure levels hundreds of times higher than those found in the general population.
Researchers report residents were exposed to PFAS from drinking water contaminated by aqueous film-forming foam (AFFF).
While previous epidemiological studies investigated low exposure levels with inconclusive results, the high levels of contamination in Ronneby allowed researchers to evaluate health effects across a broader exposure range.
“We found that children whose mothers were exposed to very high levels of PFAS during pregnancy had a substantially higher incidence of clinically diagnosed asthma,” said Annelise Blomberg, researcher at Lund University, in a news release. “The association was not observed at lower exposure levels, which may help explain why previous studies in general populations have reported mixed results.”
To conduct the study, researchers linked maternal addresses during pregnancy to water distribution records to estimate prenatal exposure. They then used asthma diagnosis data from the National Patient Register to assess individual outcomes.
Asthma is a significant cause of childhood hospitalizations, missed school days, and missed workdays for caregivers. The researchers noted that the global prevalence of the condition has increased over the last 50 years, and environmental factors like PFAS may be a contributing factor.
“PFAS contamination is a major source of high environmental exposure globally, and evidence from Ronneby offers important insights into the potential health effects of such contamination in affected communities,” said the authors in the study. “These results point to a substantial and previously unrecognized public healthcare consequence of PFAS contamination.”
The study authors noted that while the findings suggest lasting consequences for respiratory health, future studies are needed to address potential confounding variables. These include exposure beyond the prenatal period, exposure to other environmental contaminants, or smoking among household members.
“Communities around the world have been affected by PFAS contamination from aqueous film-forming foams and other industrial sources,” said Blomberg in a news release. “Our findings suggest that very high prenatal exposure may have lasting consequences for children’s respiratory health. At the same time, replication in other highly exposed populations will be important to confirm these results.”
