The Lancet has published research on a correlation between dementia and living near major roads. It’s an article only available to subscribers in full, but this is from the Findings section:
Between 2001, and 2012, we identified 243 611 incident cases of dementia, 31 577 cases of Parkinson’s disease, and 9247 cases of multiple sclerosis. The adjusted hazard ratio (HR) of incident dementia was 1·07 for people living less than 50 m from a major traffic road (95% CI 1·06–1·08), 1·04 (1·02–1·05) for 50–100 m, 1·02 (1·01–1·03) for 101–200 m, and 1·00 (0·99–1·01) for 201–300 m versus further than 300 m (p for trend=0·0349). The associations were robust to sensitivity analyses and seemed stronger among urban residents, especially those who lived in major cities (HR 1·12, 95% CI 1·10–1·14 for people living <50 m from a major traffic road), and who never moved (1·12, 1·10–1·14 for people living <50 m from a major traffic road). No association was found with Parkinson’s disease or multiple sclerosis.
Public Health Ontario gives the non-technical overview:
Led by PHO and ICES scientists, the study found that people who lived within 50 metres of high-traffic roads (like Ontario’s Hwy. 401) had a seven per cent higher likelihood of developing dementia compared to those who lived more than 300 metres away from busy roads. …
“Our study is the first in Canada to suggest that pollutants from heavy, day-to-day traffic are linked to dementia. 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,” says Dr. Ray Copes, chief of environmental and occupational health at PHO and an author on the paper. …
The increase in the risk of developing dementia went down to four per cent if people lived 50-100 metres from major traffic, and to two per cent if they lived within 101-200 metres. At over 200 metres, there was no elevated risk of dementia.
And Lloyd Alter on Treehugger.com gets the Sardonic Humor of the Week award:
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.
