We have often complained about how the traffic and pollution in our cities can make you crazy; now Public Health Ontario and Institute for Clinical Evaluative Sciences have published a study in Lancet that found that people living within 50 meters (164 feet) of busy highways had a seven percent higher likelihood of developing dementia, compared to those who lived more than 300 meters (about 1000 feet) away. The study used data on 2.2 million people, sorted by postal code and provincial health records.
Quoted in Public Health Ontario, Lead Author Dr. Hong Chen explains:
Little is known in current research about how to reduce the risk of dementia. Our findings show the closer you live to roads with heavy day-to-day traffic, the greater the risk of developing dementia. With our widespread exposure to traffic and the greater tendency for people to live in cities these days, this has serious public health implications.
It has serious urban planning, land use and other implications as well, raising questions of why we permit the development of housing so close to highways now that it almost hangs over on top of them; Why we allow dirty diesel trucks on our urban roads, and why we don’t invest more in alternatives to driving. As another contributor to the study, Dr. Ray Copes, notes:
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. This study suggests air pollutants that can get into the brain via the blood stream can lead to neurological problems.
The Guardian speaks to a few experts, who both downplay the significance of the study, but do note that “this study presents one more important reason why we must clean up the air in our cities.”
It’s amusing that this study comes from the Province of Ontario, where they spend billions widening highways into cities, where light rail proposals are fought tooth and nail because they will block lanes that could carry cars, where the Mayor of Toronto is spending a billion bucks to fix up a highway that saves a few thousand people a few minutes a day, and then everybody wonders why the costs of health care are getting so high.