Does proximity to high volumes of car traffic lead to autism?

Maybe, maybe not, but research by the University of Southern California and published in JAMA Psychiatry shows an association with autism in children born in an environment with elevated levels of nitrogen dioxide and micro-fine particulate pollutants. The USC researchers say further epidemiological and toxicological examinations of likely biological pathways will help determine whether these associations are causal.

This study is not a smoking gun for autism, but we already know fine particulate matter causes brain damage.

Earlier research in Southern California has shown that exhaust nanoparticles are easily absorbed into brain tissue and are toxic to brain cells. In experiments with animal tissue, researchers saw the poisons inflame and damage brain cells and inhibit brain tissue growth in cell cultures. Furthermore, they saw the exhaust particles damages brain blood vessels, causing cognitive decline through reduced blood flow into the brain.

This is in addition to other direct damage caused by driving cars such as various respiratory diseases (from emissions), stress-induced illnesses (from road noise), and various cancers (from VOC, NOx, and maybe PM).

Abstract is here; full journal article available to subscribers.