Bottom Line: In a study of estimated exposure to air pollution at mothers' homes during pregnancy, 1 of 3 airborne pollutants was associated with increased risk of autism spectrum disorder (ASD) in children in a Canadian metropolitan area with relatively low ambient air pollution levels. What causes ASD isn't known but some previous research has suggested environmental contaminants and air pollution may be potential risk factors. This study included nearly all births in Vancouver, British Columbia, from 2004 through 2009. Among 132,256 births, 1 percent of children (1,307) were diagnosed with ASD by age 5. Of three pollutants, nitric oxide (NO) was positively associated with increased risk of ASD after accounting for other potential mitigating factors. NO was used as an indicator of traffic-related pollution. Other potential unaccounted factors could tamp down the study findings; direct assessment of air pollution exposure wasn't possible; and the study cannot draw causal inferences.

Authors: Lief Pagalan, M.Sc., Simon Fraser University, British Columbia, Canada, and coauthors

###

To Learn More: The full study is available on the For The Media website.

(doi:10.1001/jamapediatrics.2018.3101)

Editor's Note: The article includes funding/support disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.