INDIANAPOLIS — A new study shows heavy traffic causes more than a headache–it can also cause brain damage.

Researchers at the University of British Columbia published a new study in the journal Environmental Health that shows exposure to heavy diesel fumes in traffic can alter brain function in as little as two hours.

Researchers exposed 25 people to diesel exhaust and clean air at different times, measuring brain activity before and after the exposure.  

People who were exposed to the fumes experienced changes to the parts of the brain that control memory and internal thought.  Those different areas of the brain showed a decrease in connectivity with each other.  The main concern is that changes to that connectivity have been associated with reduced cognitive performance and symptoms of depression.

The good news is the effects of the fumes were temporary; brain activity and the participants returned to normal. However, experts worried that continuous exposure to the diesel fumes could result in long-term effects.

If commuting in heavy traffic is an unavoidable part of your life, researchers recommend keeping your vehicle windows rolled up when you’re in traffic. They also suggest making sure your vehicle’s air filter is in good shape to keep as many fumes out as possible. If you walk or bike to work, they recommend trying to avoid high-traffic areas during rush hour when you can.

The people behind the study noted the timeliness of this research as more employers are calling employees back to the office–and back to daily commutes.