Study Links Pollution From Traffic to Autism Risk

Exposure to air pollution from traffic during pregnancy and the first year of life increases an infant's risk of autism, according to a study released today by USC and Children's Hospital Los Angeles.

The researchers behind the study, titled "Traffic Related Air Pollution, Particulate Matter, and Autism," say exposure to traffic-related air pollution during pregnancy and early life is linked to a more than two-fold risk of autism.

In addition, exposure to regional pollution consisting of nitrogen dioxide and small pollution particles is also associated with autism, even if the mother did not live near a busy road, according to research published in the Archives of General Psychiatry, a sister publication of the Journal of the American Medical Association.

The USC/CHLA study found that children whose mothers lived in areas with high levels of pollution from traffic or with poor air quality during pregnancy or the first year of life may be more likely to have autism.   

"This work has broad potential public health implications," said the study's principal investigator, Dr. Heather Volk, assistant professor of preventive medicine at USC's Keck School of Medicine and an investigator at CHLA.

"We've known for a long time that air pollution is bad for our lungs, and especially for children," she said. "We're now beginning to understand how air pollution may affect the brain."

The research is the first to look at the amount of near-roadway traffic pollution to which individuals were exposed and combine that with measures of regional air quality, Volk said.

The study builds on previous research that examined how close subjects lived to a freeway, Volk said.

"We took into account how far away people lived from roads, meteorology such as which way the wind was blowing, how busy the road was, and other factors to study traffic-related pollution," she said. "We also examined data from air quality monitors, which measure pollution over a larger region that could come from traffic, industry, rail yards or many other sources."

Ronald Leaf, psychologist and a director at the Seal Beach-based Autism Partnership, said he hadn’t read the study yet, but he’s seen his share of reports claiming to have found a cause for autism and advises people to be skeptical.

“Every year they come out with new studies that sort of link causes to autism, and typically they don’t pan out,” Leaf said. “Perhaps this one will."

However, Leaf said, “It’s probably preliminary at best.”

According to Leaf, there’s a lot of misinformation and rumor floating around regarding autism, and people should fully investigate any claims they hear about the disorder – specifically by reading peer-reviewed scientific journals.

-- City News Service

-- Patch Reporter John Crandall contributed to this story.