When it comes to your kid’s brain development, don’t breathe easy. Scientists have uncovered more startling evidence that our children’s exposure to environmental toxins and pesticides is linked with increased rates of autism and intellectual disabilities in the United States, according to new findings published in the journal PLOS Computational Biology and reported by Medical News Today.

For the study, researchers at the University of Chicago analyzed medical information from the insurance claims of almost 100 million U.S. patients. Scientists specifically looked for levels of congenital malformations (a.k.a. birth defects) in the reproductive systems of male children. (These conditions in males are believed to also indicate a parent’s exposure to environmental factors such as pollution.)

Findings showed that young boys with autism are almost six times more likely to have congenital malformations, such as micropenis and undescended testicles, at birth.

Next, researchers reviewed incident rates of autism and intellectual disabilities (IDs) county by county. Scientists discovered that for every 1 percent increase in these malformations, there was a 283 percent rise in autism rates and a 94 percent increase in IDs across the board. In addition, nearly all of the areas with higher autism rates in the study also showed higher ID rates.

“Autism appears to be strongly correlated with rate of congenital malformations of the genitals in males across the country,” said Andrey Rzhetsky, MS, PhD, a member of the research team. “This gives an indicator of environmental load, and the effect is surprisingly strong.”

The team’s findings also support previous studies that show pregnant women exposed to high levels of air pollution are twice as likely to have autistic children and another that suggested chemical exposure has a detrimental impact on brain development.

Several other studies show that boys’ genetic makeup makes them more susceptible to both air pollution and neurological disorders while in the womb. Click here for more information.