Wildfire Smoke Exposure During Pregnancy Increases Autism Risk in Children

Each increase of 0.75 micrograms per cubic meter in the average concentration of wildfire-related fine particulate matter in the air during pregnancy was associated with an approximately 30% increase in the risk of autism.

The strongest associations with autism were observed during the second and third trimesters of pregnancy.

"Pregnancy is a period of rapid brain development, when exposure to environmental factors can disrupt critical developmental processes," said Stefania Papateodorou, an epidemiologist at Rutgers University's School of Public Health and the study's lead author, Euronews reports.

Autism is associated with complex neurodevelopmental processes that begin before birth, when the brain develops rapidly and connections between nerve cells are formed.

She added that the findings highlight the importance of monitoring wildfires and their potential impact on air quality during pregnancy.

The study examined approximately 900,000 mother-child pairs in the United States, who were followed for an average of 6.3 years.

Wildfire smoke contains fine particulate matter, gases and other pollutants. Its composition can vary depending on what is burning, as fires can destroy plastics, electronic devices and paints, releasing toxic chemicals into the air.

These particles can penetrate deep into the lungs and trigger inflammation throughout the body. This is one possible mechanism through which smoke exposure may affect pregnancy and fetal development.

"Wildfire smoke can travel far beyond the areas directly affected by fires, meaning people may be exposed to it even when they cannot see or smell the smoke," Papateodorou noted.

Wildfire smoke has already been linked to a range of adverse health effects, including asthma, chronic lung diseases and mental health disorders.

The authors emphasized that their study was observational and therefore cannot establish a cause-and-effect relationship between wildfire smoke exposure and autism.

"Understanding how prenatal exposure to environmental factors may contribute to autism, alongside genetic and other factors, remains an important area of scientific research," Papateodorou said.

Measures to reduce smoke exposure during pregnancy, including more accurate air quality forecasting and strategies to prevent smoke from entering indoor spaces, could help protect the health of mothers and children.