Wildfire smoke exposure in pregnancy linked to higher autism risk in children, study finds
A Rutgers University study of nearly 900,000 mother-child pairs found higher prenatal exposure to wildfire smoke increased autism diagnosis risk.
Exposure to wildfire smoke during pregnancy is associated with a higher risk of a child later being diagnosed with autism, a new study concludes. The research from Rutgers University, published in JAMA Pediatrics, analyzed health records of nearly 900,000 mother-child pairs across the United States. It found that increased prenatal exposure to fine particulate matter from wildfire smoke correlated with a greater likelihood of an autism diagnosis. The heightened risk was most pronounced during the second and third trimesters of pregnancy.
"We already know that exposure to wildfire smoke is harmful," said Stefania Papatheodorou, an OB-GYN and epidemiologist at the Rutgers School of Public Health, who led the study. "There is very little evidence on how exposure to wildfire smoke during pregnancy could affect neurodevelopment during childhood. That's why we decided to combine these questions together and examine this association in a large database." The study used modeled estimates of weekly wildfire smoke concentrations where each pregnant person lived. For every incremental rise in this type of air pollution, the risk of autism rose by 30 percent.
The research focused on PM 2.5, fine particles that are 30 times smaller than the width of a human hair and easily inhaled. These particles can lodge deep in the lungs, enter the bloodstream and cause respiratory and cardiovascular problems. They pose a particular risk to vulnerable groups, including children, seniors and people with conditions like asthma. Papatheodorou advises obstetricians to factor environmental hazards like wildfires into routine prenatal care and recommends pregnant people limit outdoor time when air quality is poor and use home air purifiers.
READ MORE: Study finds climate change coverage surged in 2023 wildfire reporting
READ MORE: Wildfire smoke deaths in Canada surge 275 percent since early 2000s, report finds
"It doesn't have to be visible for the outside [particulate matter] levels to be harmful," Papatheodorou said. "So, instead of waiting until they see a big cloud coming, they can always check the air quality on their phones, which will alert them that, for example, the levels are not appropriate for groups that are sensitive." Wildfire smoke can travel vast distances, affecting communities far from the actual fires. Smoke from Canadian wildfires, for example, led to several days of poor air quality in the Philadelphia region in 2023, forcing school closures and flight delays.
Scientists warn that climate change is increasing the frequency and intensity of wildfires, as hotter temperatures dry out vegetation. A report by the New Jersey Department of Health found the 2023 wildfires caused a spike in emergency room visits for new asthma diagnoses in the state. New Jersey firefighters have recently contended with an unseasonably high number of wildfires triggered by severe drought. "The population disease burden is going to increase with the increased exposure to fires. So, it is something that we need to pay a lot of attention to," Papatheodorou said. As an observational study, this research cannot prove wildfire smoke causes autism, and Papatheodorou said more studies are needed to confirm the link. She emphasized that public awareness of the health risks is crucial so people can take protective measures.
With files from WHYY