While Arkansas has been under the national average in air pollution for the past four years, and continues to be on the decline, it’s still an issue. For expectant mothers, it can be a major concern.

A new study has found that pregnant women exposed to higher levels of air pollutants – specifically PM10 (pollutant particles produced by sources such as power plants, cars, air traffic and railways) — had children with lower IQs compared to women exposed to lower levels.

The study led by University of Washington and University of California, San Francisco accessed the IQs of a little over 1,000 pregnant women’s offspring between the ages of four and six. Researchers found that children whose mothers lived in the highest 10 percent of exposure had IQ scores 2.5 points lower than those in the lower 10 percent.

Here’s where folic acid, and its natural form folate, come into play.Researchers also found the supplement may offset some effects of air pollution. They found the difference between offspring IQs in the highest and lowest PM10-exposed groups had widened to 6.8 points among those whose mothers had the lowest levels (bottom 25 percent) of folate.

Study authorssay that they could not explain how PM10 exposure contributes to lower IQ, but that animal studies indicate that air pollution exposure increases maternal inflammation and oxidative stress.

“While it’s beyond the scope of our paper to understand how folate might alter this association, it is possible that higher folate levels increase the antioxidant capability of the diet, buffering oxidative stress associated with PM10 exposure,” says senior author Kara LeWinn, associate professor of psychiatry at the University of California, San Francisco School of Medicine.

You can find the original study, posted to Science Direct, here.