A study of about 900,000 mother-child pairs found that increases in wildfire-related fine particles during pregnancy were associated with a 30% higher risk of autism per 0.75 µg/m³ rise, especially in the 2nd and 3rd trimesters. The researchers note associations, not causation, and emphasize monitoring air quality and reducing exposure for pregnant individuals. The study covers long-term follow-up (~6.3 years) and discusses potential biological pathways via inflammation and prenatal neurodevelopment.