Autism math: Genetics and pollution exposure over time may boost risk
A federal grant may enable Keck School researcher to pinpoint how and when air pollutants influence developmental delays or autism

Is air pollution really one of the culprits behind autism, and how? A Keck School of Medicine of USC researcher is a step closer to finding out.
Armed with a new $2 million grant from the National Institutes of Health, epidemiologist Heather Volk will dig deeper into the relationship between a children’s exposure to air pollution before birth and their risk of developing autistic traits or having cognitive developmental delays.
While some studies have implicated early exposure to air pollution in both cognitive developmental delay and increased autism risk, those studies only examined the relationship at one point in time. Volk now will look at exposure to air pollution over children’s first three years of life. By tracking autistic traits and cognitive development in several hundred children as they grow, Volk hopes to shed light on whether the risk persists over time and whether there is a critical point when air pollution may influence development of autism spectrum disorders.
One in 68 U.S. children now has an autism spectrum disorder, a 30 percent increase from 2012.
Centers for Disease Control and Prevention
Volk, assistant professor of research in preventive medicine and pediatrics, has been looking into the environmental risk factors that — when combined with a strong genetic risk — might help explain pathways involved in autism. In 2010, she and her colleagues showed that children born to mothers living within 1,000 feet of a freeway were twice as likely to have autism as other children. More recently, in a January article in Epidemiology, she and her colleagues showed that children with a certain genetic makeup who were exposed to high levels of air pollution had a higher risk of autism. The research implicated a variation in the MET gene.
“I hope that the study can show how prenatal air exposure can affect autism risk and children’s cognitive ability over time and identify opportunities for broader public health interventions,” Volk said.
Learn more about the USC autism and air pollution studies on this video.