Prenatal traffic pollution exposure tied to autism risk in boys
A new study has linked prenatal exposure to traffic-related air pollution with an increased risk of autism spectrum disorder in boys. Researchers found that higher levels of black carbon during pregnancy were associated with a 1.5 times greater likelihood of autism diagnosis. The findings come from a cohort of over 1,400 children in the Netherlands.
The study, published on September 19, 2024, in JAMA Network Open, examined data from the Generation R cohort in Rotterdam, Netherlands. This prospective study followed pregnancies from 2002 to 2006, tracking 1,400 children until ages 9 to 10 for autism spectrum disorder (ASD) diagnoses.
Researchers estimated prenatal exposure to traffic-related air pollution (TRAP) using advanced models that incorporated traffic intensity, population density, and building heights. The pollutants analyzed included black carbon (BC), fine particulate matter (PM2.5), and nitrogen dioxide (NO2).
Key results showed that boys with higher prenatal BC exposure had a 1.5 times increased risk of ASD compared to those with lower exposure. Associations were also noted for PM2.5 and NO2, though less pronounced. No significant link was observed in girls, suggesting potential sex-specific vulnerabilities.
Lead author Caroline M. A. Mol, MD, PhD, from Erasmus MC University Medical Center Rotterdam, stated, "Our findings suggest that reducing exposure to traffic-related air pollution during pregnancy could help prevent ASD, particularly in boys."
The study adjusted for factors like maternal education, smoking, and socioeconomic status to isolate pollution's effects. ASD diagnoses were confirmed through clinical assessments and questionnaires at follow-up.
This research builds on prior evidence linking air pollution to neurodevelopmental issues, highlighting the need for urban planning to minimize TRAP near residential areas. However, the authors note limitations, including reliance on modeled exposure data rather than direct measurements.