People who live near busy roads seem to be more prone to developing dementia than those who live further away from these arteries. This is the conclusion of a large study published in the Lancet which suggests that air pollution generated by vehicles could be a risk factor for neurological disease.
A study published this week in the journal The Lancet indicates that Ontario residents who lived within 50 meters of a freeway or other high traffic road were 7% more likely to develop dementia than those who lived more than 300 meters from busy thoroughfares.
This increased risk drops to 4% for those whose residence is located at a distance of 50 to 100 meters from a clean road with heavy traffic. The authors of the study evaluated this same increase in risk at 2% for a distance of 100 to 200 meters.
Researchers from the Public Health Agency of Ontario (PHO) and the Institute for Clinical Evaluative Sciences (ICES) have also found that citizens who have always lived near major arteries are all the more vulnerable to dementia than those who have lived in these same areas for a shorter time, pointed out one of the authors, Dr Ray Copes.
The risks would thus increase by 12% for people who lived 50 meters from a road heavily used by vehicles for a prolonged period.
However, scientists did not reach the same conclusions regarding two other chronic neurological disorders: Parkinson’s disease and multiple sclerosis.
Observing the medical records of 6.5 million people
The study is based on an analysis of the medical records of 6.5 million Ontarians between the ages of 20 and 85. Those who suffer from a neurological disease were excluded from the researchers’ field of analysis. The experts went back in time, to 1996, to determine how far from a major road artery the study subjects had lived, according to the postal codes of the addresses where they lived. During the follow-up study from 2001 to 2012, scientists identified nearly 244,000 people aged 55 and older with dementia across the province. “With our widespread exposure to traffic and with the significant tendency of people to live in cities these days, this has serious public health implications,” argued the study’s lead author, Dr. Hong Chen.