It’s official: Commuting to work not only makes you miserable, but shrinks your brain, too. According to a new study, a daily dose of polluted air may change your brain in ways that’ll lead to cognitive impairment. 

 Researchers studied 943 healthy adults in the New England region. They used magnetic resonance imaging (MRI) to examine the participants’ brain structures. Afterwards, they differentiated the images with the air pollution level of the participants’ location. This is the first study focusing on the relationship between air pollution and older adults. Other studies examined links between air pollution and the brain of children.

 When pollution in your area increases by only 2 mg per cubic meter in fine-particle pollution, your brain reduces in size by as much as 0.32 % in volume. Fine-particle pollution is pretty common, coming from car exhaust and other pollutants found across the average city (another good reason to get out of town, maybe?).

 Study Author Elissa H. Wilker, a cardiovascular epidemiology researcher at Beth Israel Deaconess Medical Center in Boston says, the reduction in brain volume is equal to “about one year of brain aging.”

 Not only does it cause your brain to age, but researchers also found that the participants living in areas with higher levels of pollution were at higher risk of silent strokes. “Silent strokes” don’t usually exhibit symptoms, but can be observed on brain scans, and have been linked to dementia and poorer cognitive function.

 Take note, however, that the study was conducted at one point in time, which does not prove a cause-and-effect relationship between air pollution and its effects on the brain.

 You’ll find the study published on April 23 in the American Heart Association journal Stroke.

 You can help decongest the metro. There are ways to avoid contributing to air pollution and traffic. Walk, bike, or carpool on your way to work. Combine trips by using the bus, subway, light rail system, or commuter train as an alternative to driving your car.

Happy Earth Day!