Air pollution caused by traffic can leave your health feeling like it was hit by a car—causing and worsening problems like asthma, allergies, and respiratory diseases like bronchitis and COVID-19. Now a new paper suggests that there’s a link between traffic pollution and another horrible illness: dementia.

A meta-analysis published Wednesday in the paper Neurology found that people who lived in areas with higher rates of traffic pollution had an increased risk of dementia. While the link doesn’t conclusively prove that the pollution causes the neurodegenerative condition, the study’s authors do note that people should reduce their exposure to bad air.

“Since a report by the World Health Organization showed that more than 90 percent of the world’s population lives in areas with higher than recommended levels of air pollution, our results provide more evidence for enforcing regulations for air quality and accelerating the transition from fossil fuels to sustainable energies,” Ehsan Abolhasani, a neuroscientist at McGill University and co-author of the study, said in a press release.