Autism (ASD) affects one out of every 88 children and is the fastest growing serious developmental disability in the United States. Recent research has shown this number may be as many as 1 in every 50 schoolchildren being diagnosed with ASD.  It is thought to be caused by a combination of genetics and environmental factors, however, the exact cause is not yet understood.
Research studies have pointed to a number of environmental factors that can increase the risk of autism, including having the flu or fever during pregnancy and the father’s age at conception. A recent study shows a link between air pollution and the risk of autism.
According to the study, women who are pregnant and exposed to high levels of air pollution are twice as likely to have a child with autism. The study was completed at Harvard School of Public Health and published in Environmental Health Perspectives in June 2013.
Previous studies have shown an association between air pollution and ASD. A study published in 2010 found that children who lived near freeways were twice as likely to develop autism. Results showed that when a child’s home (at the time of birth) was within 1013 feet of a freeway, the risk of developing autism doubled.  Another study, published in late 2012, also found a link between traffic pollution and the risk of autism, finding that “kids whose homes had the greatest levels of modeled traffic-related air pollution had a 3 times higher chance of autism compared to those living in places with the lowest exposure.” 
The most recent study, according to the authors, is the first nationwide study. Both the previous studies have only looked at limited areas. This study analyzed information from the Nurses’ Health Study II, looking at data on 325 women who had a child diagnosed with autism and 22,000 women who had children that were not diagnosed with ASD.
After factoring in smoking, education and income, the researchers looked at how much air pollution the mothers were exposed to during their pregnancy. The results showed:
- Pregnant mothers living in areas with higher levels of diesel and mercury in the air had twice the risk of having a child with autism
- Pregnant mothers living in areas where other pollutants (lead, methylene chloride, manganese and other metals) had a 50 percent higher risk of having a child with autism
- The risk increased for boys
The senior author, Marc Weisskopf, would like to see further research the looks at the levels of metals and other pollutants in the blood of pregnant women and newborn children to “provide stronger evidence that specific pollutants increase risk of autism.”  He believes that further research and understanding could lead to ways to reduce women’s exposure to these pollutants.
 “Air Pollution Raises Autism Risk,” 2013, June 18, Staff Writer, Medical News Today
 “Autism and Traffic Pollution Link Found,” 2010, Dec. 17, Staff Writer, Medical News Today
 “Autism Risk Increases With Exposure to Air Pollution,” 2012, Nov. 27, Staff Writer, Medical News Today
 “Facts about Autism,” 2012, Staff Writer, Autism Speaks
Published On: July 10, 2013