High Levels of Air Pollution Increase Risk for Autism During Pregnancy

Scientists believe that pregnant women who are exposed to high levels of air pollution may be putting their child at a higher risk for autism in some cases, according to a recent study.

Researchers looked at pregnant women who lived near heavily-polluted areas, and found that they were up to two times as likely to have a child with an autism spectrum disorder (ASD) compared to those who lived in the least-polluted areas.

Lead study author Andrea Roberts, research associate in the Harvard School of Public Health Department of Social and Behavioral Sciences, said exposure to diesel particulates, lead, manganese, mercury, methylene chloride and other pollutants have been known to affect brain function and a child's cognitive development.

Researchers looked at 325 women who had a child with autism, along with 22,000 women who had a child with the illness. Air-pollution data from the U.S. Environmental Protection Agency also allowed researchers to estimate levels of pollutants at the time and place of the child's birth.

Results showed that women living in areas with the highest levels of diesel or mercury in the air were twice as likely to have a child with ASD, compared with those living in the areas with the lowest levels.

The findings showed that 279 boys and 46 girls had ASD in the study. The link with pollution seemed strong among boys. Researchers said they are hoping to study this explanation further.

However, researchers note that the gender difference may be due to boy's generally greater vulnerability to ASD, as the toxic effects of air pollutants can impact boys' development more easily, according to researchers.

The study was published today (June 18) in the journal Environmental Health Perspectives.