Researchers Find Link between Autism and Environmental Toxins

University of Chicago scientists have found that environmental pollution could increase autism and intellectual disability (ID) risk in children. Their study was based on data from over 100 million U.S. medical records.

According to researchers, presence of harmful pollutants such as pesticides in environment led to a dramatic increase in autism and ID diagnoses. Autism rates rose by 283 percent while ID risk jumped 94 percent for every one percent increase in genital malformation in a county. Genital malformation in newborn males is an indicator of environmental pollution exposure.

Male babies are sensitive to common pollutants such as lead, synthetic sex hormones and medications. Children, whose parents are exposed to these toxins, are at increased risk of suffering from malformations such as micropenis and undescended testicles, according to a news release.

Autism can cause significant social, communication and behavioral challenges. Previous research has shown that both genes and environment raise autism risk. Children with intellectual disabilities have below-average intellectual function and don't have the ability to perform daily tasks.

For the study, researchers obtained data from 100 million U.S. health insurance claims. The team looked at data from different counties to assess the difference in rates of autism and ID.

Researchers found a co-relation, but not causation, between environmental toxins and autism/ ID diagnosis. Autism rates in females were also linked with malformation levels, but they showed a weak link.

"Autism appears to be strongly correlated with rate of congenital malformations of the genitals in males across the country," said Andrey Rzhetsky, professor of genetic medicine and human genetics and one of the study authors. "This gives an indicator of environmental load and the effect is surprisingly strong."

The study is published in the journal PLOS Computational Biology.