Two new studies have found an association between relatively low levels of air pollution and children’s risk of autism spectrum disorder (ASD), Salon reports.
One study, published in JAMA Pediatrics, studied 132,000 births in Vancouver, Canada, from 2004 to 2009. Researchers concluded there was a link between exposure to nitric oxide from car exhaust during pregnancy and greater incidence of childhood ASD.
The second study, published in Environmental Epidemiology, observed more than 15,000 infants born in Denmark between 1989 and 2013. It found that air pollution exposure during the first months of life and later was also associated with ASD.
“The study showed a small increase in autism for infants exposed before birth to one of the pollutants: nitric oxide. While it’s a small increase, if large populations are exposed, it could still affect many children,” Lynn Singer, PhD, professor of population and quantitative health sciences, pediatrics, psychiatry, and psychology at the School of Medicine at Case Western Reserve University in Ohio, told Healthline.
“It confirms some previous research and suggests that air pollution should be studied further regarding how it relates to autism,” she added.
However, neither study proved that air pollution is causing ASD.
The researchers have only found that children in an area with air pollution are at a greater risk.