Authors: David Howett, University of Cambridge, UK
The contribution of environmental risk factors to the pathogenesis of dementia has a long research history, but has eluded mechanistic understanding. A recent article published in The Lancet by Hong Chen from Public Health Ontario, Canada, indicates that proximity to heavy traffic is associated with a higher incidence of dementia, but not Parkinson’s disease or multiple sclerosis.
The study examined residential proximity to major roads over 11 years using Ontario’s Registered Person’s Database encompassing nearly the entire adult population of Ontario, including approximately 2.2 million individuals aged 55–85. The participants were Canadian-born and free from neurological disease at cohort inception in 2001; approximately 20% lived rurally but the majority resided within 200 meters of a major road.