New research suggests exposure to pollution can increase the risk of autism and schizophrenia.
Researchers found that mice exposed to harmful pollutants exhibited an increase in size in a specific region of the brain; this enlargement is often seen in humans suffering from these conditions, a University of Rochester Medical Center news release reported.
These mice also tended to perform poorly on "short-term memory, learning ability, and impulsivity" tests.
"Our findings add to the growing body of evidence that air pollution may play a role in autism, as well as in other neurodevelopmental disorders," Deborah Cory-Slechta, Ph.D., professor of Environmental Medicine at the University of Rochester and lead author of the study, said in the news release.
The findings suggest that children who were exposed to heavy traffic-related pollution during the first year of their lives were three times more likely to develop autism.
Researchers exposed mice to the levels of pollution seen in mid-sized U.S. cities during the first weeks of their lives.
"When we looked closely at the ventricles, we could see that the white matter that normally surrounds them hadn't fully developed," Cory-Slechta said. "It appears that inflammation had damaged those brain cells and prevented that region of the brain from developing, and the ventricles simply expanded to fill the space."
These mice also had elevated levels glutamate, which is a neurotransmitter linked to autism and schizophrenia in humans.
Most air pollution consists of tiny particles of carbon. There have been scores of studies on how this type of pollution affects the lungs, but not so much on how it affects the brain.
Larger particles are less harmful because they are usually coughed up. Ultra-fine particles, which are not regulated by the Environmental Protection Agency (EPA), are more dangerous.
"I think these findings are going to raise new questions about whether the current regulatory standards for air quality are sufficient to protect our children," Cory-Slechta said.
