A new study from the Harvard School of Public Health has established a potential link between air pollution and autism risk. According to the research, living in area with high levels of air pollution may increase a woman's chance of having a child with autism.

According to Autism Speaks, Harvard researchers had reported last year strong evidences that prenatal exposure to high air pollution can up to double the chance that a child may develop autism.  Exposure to diesel particles, lead, manganese, mercury, methylene chloride and other pollutants are known to affect brain function and to affect the developing baby.

 "Women who were exposed to the highest levels of diesel or mercury in the air were twice more likely to have a child with autism than women who lived in the cleanest parts of the sample," Harvard School of Public Health Department of Social and Behavioral Sciences Research Associate Andrea Roberts told The Huffington Post.

The study appeared online June 18, 2013 in Environmental Heath Perspective.

According to the press release by Harvard School of Public Health, two previous studies found associations between exposure to air pollution during pregnancy and autism in children; however those studies looked at data in just three locations in the United States.

The Harvard researchers looked at associations between autism and levels of pollutants at the time and place of birth. They used air pollution data from the U.S. Environmental Protection Agency to estimate women's exposure to pollutants while pregnant. They also adjusted for the influence of factors such as income, education, and smoking during pregnancy.

In a report by Bloomberg, as said by the Centers for Disease Control and Prevention, one in 50 US children are diagnosed with autism or a related disorder. Children with autism may be unresponsive to people, become indifferent to social activity and have communication difficulties.

A separate study from Stanford University and published in Proceedings of the National Academy of Sciences is the first to suggest that weak connections between brain regions for speaking and reward may be why.

"There isn't a lot of data to strongly point at what are the root causes of the social deficits in children with autism," California's Stanford University Postdoctoral Research Fellow Daniel Abrams said in a telephone interview. "We think it has this important motivation and reward component to it."

The cause of autism is unknown but experts consider genetic factors as significant influences that may contribute to the condition. But for now, air pollution is considered to increase the risks.