Overview
- The Rutgers-led analysis published Tuesday in JAMA Pediatrics used Medicaid records for 893,212 mother–child pairs born 2007–2014 to examine prenatal exposure to wildfire fine particulate matter (PM2.5).
- Researchers found that each 0.75 microgram-per-cubic-meter rise in average wildfire-related PM2.5 during pregnancy was associated with about a 30% higher risk of an autism diagnosis, with the strongest links after the 15th week of gestation.
- The study used weekly, ZIP-code-level modeled estimates of wildfire PM2.5 and was observational, so it cannot prove wildfire smoke causes autism and may be affected by exposure misclassification or unmeasured confounding and limited generalizability beyond Medicaid enrollees.
- Authors urged pregnant people to watch local air-quality reports and use exposure-reduction steps such as staying indoors during smoke events, using indoor air filtration, and wearing well-fitting particulate respirators when needed, and they encouraged clinicians to include environmental counseling in prenatal care.
- Because wildfire smoke can travel long distances and prior studies were mixed, the team called for replication, mechanistic research into how particles might affect fetal brain development, and analysis of more recent birth cohorts as wildfire smoke exposure grows; the work was funded by NIEHS (NIH grant R01-ES034038).