Living near a highway may increase dementia risk by 7 per cent

[Emily]

https://www.newscientist.com/articl...way-may-increase-dementia-risk-by-7-per-cent/

Short Sharp Science
4 January 2017
[h=1]Living near a highway may increase dementia risk by 7 per cent[/h] By New Scientist staff and Press Association
Living close to a motorway or highway may increase the risk of developing dementia, according to a study of more than six million adults in Canada.
Tracking these people over a period of 11 years found a clear link between dementia incidence and living near a main road, comparable to the M1 or M4 in the UK, or major state or interstate highways in the US. Compared with those whose homes were more than 300 metres away from a busy road, people living within 50 metres of heavy traffic had a 7 per cent higher risk of developing dementia.
This increase falls to 4 per cent in people living between 50 to 100 metres of a busy road, and 2 per cent in people living between 101 and 200 metres. At greater distances, there was no evidence of a link with the condition...

Journal reference: The Lancet, DOI: 10.1016/S0140-6736(16)32399-6

 

[Gert van der Hoek]

There could be confounding factors. F.i. income , economic and social status.

 

[Emily]

They seem to have attempted to account for some of those factors:

"adjusting for individual and contextual factors such as diabetes, brain injury, and neighbourhood income. We did various sensitivity analyses, such as adjusting for access to neurologists and exposure to selected air pollutants, and restricting to never movers and urban dwellers."

Maybe raising the diabetes risk is raising the dementia risk:

http://care.diabetesjournals.org/content/35/1/92.short
Diabetes Incidence and Long-Term Exposure to Air Pollution