People who live near a major road are more likely to develop dementia than those who live further away, according to new research.
The study, published in The Lancet medical journal, found that people who live within 50 meters (164 feet) of a major roadway are 12% more likely to be diagnosed with dementia than their counterparts who live elsewhere. Researchers say that traffic exposure could be responsible for up to one in 10 cases of dementia among people who live near major roads.
“Despite the growing impact of these diseases, little is known about their causes and prevention,” says study author Hong Chen of Public Health Ontario. “Busy roads could be a source of environmental stressors that could give rise to the onset of dementia.”
Read More: How Bad Air Came Back
Researchers behind the study tracked 6.6 million adults living in Canada between 2001 and 2012 using postal codes to determine their proximity to a major road. Two pollutants from vehicle exhaust—nitrogen dioxide and particulate matter—were connected to dementia but researchers say they do not account for the full effect.
Air pollution has increased in severity in many parts of the world in recent years thanks to rapid economic growth and changes in fuel sources. The study is the latest in a slew of research to show the devastating effect air pollution can have on human health. Other studies have shown how smog can damage the functioning of the cardiovascular and respiratory systems and more recently harm developing fetuses. Several initiatives across the globe have been launched in recent years to address the issue.