There may be a link between traffic pollution and autism.

Researchers at the University of Southern California used data from the U.S Environmental Protection Agency to figure out levels of pollution for addresses in the state.

That information was compared to exposure to pollution in the womb and during the first year of life for hundreds of children with and without autism.

The team found children in homes exposed to the most pollution were three times as likely to have autism compared with children residing in homes with the lowest levels of exposure.

The details are found in the Archives of General Psychiatry Journal.