Living near heavy traffic may come with more than just dealing with incessant honking. According to a new study, it may also raise your rise for developing dementia.
A widespread population study from Public Health Ontario, published Wednesday in the journal the Lancet, followed more than 6 million people in Ontario, Canada, over more than ten years, and found that living close to heavy traffic was "associated with a higher incidence of dementia."
The closer you live, it seems, the greater the risk. People who had lived between 101 and 200 meters from a busy roadway had a 2% greater risk of developing dementia; people who had lived 40 to 100 meters away had a 4% greater risk; and people who had lived within 50 meters of a major road had a 7% greater risk of developing dementia.
The greatest risk of all was among the people in the study who lived within 50 meters of a busy road for the entire length of the study's duration: They had a 12% higher risk of developing dementia, according to coverage of the study from the Guardian.
"Our study is the first in Canada to suggest that pollutants from heavy, day-to-day traffic are linked to dementia," Dr. Ray Copes, one of the study's authors, said in a statement from Public Health Ontario.
"We know from previous research that air pollutants can get into the blood stream and lead to inflammation, which is linked with cardiovascular disease and possibly other conditions such as diabetes," Copes said. "This study suggests air pollutants that can get into the brain via the blood stream can lead to neurological problems."
The findings are especially pertinent, given that more than half of the world's population now lives in cities.
"With our widespread exposure to traffic and the greater tendency for people to live in cities these days, this has serious public health implications," Dr. Hong Chen, the study's lead author, said in the statement.
Copes hopes the findings might influence the decisions of urban planners and building designers, according to the statement.
This large-scale population study will likely inform more targeted research to definitively confirm the relationship between heavy traffic and dementia.