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Living Near Heavy Traffic Increases Risk of Dementia, Study Finds (theguardian.com)
An anonymous reader quotes a report from The Guardian: People living near a busy road have an increased risk of dementia, according to research that adds to concerns about the impact of air pollution on human health. Roughly one in 10 cases of Alzheimer's in urban areas could be associated with living amid heavy traffic, the study estimated -- although the research stopped short of showing that exposure to exhaust fumes causes neurodegeneration. Previously, scientists have linked air pollution and traffic noise to reduced density of white matter (the brain's connective tissue) and lower cognition. A recent study suggested that magnetic nano-particles from air pollution can make their way into brain tissue. The latest study, published in The Lancet, found that those who live closest to major traffic arteries were up to 12% more likely to be diagnosed with dementia -- a small but significant increase in risk. The study, which tracked roughly 6.6 million people for more than a decade, could not determine whether pollution is directly harmful to the brain. The increased dementia risk could also be a knock-on effect of respiratory and cardiac problems caused by traffic fumes or due to other unhealthy life-style factors associated with living in built-up urban environments. The study tracked all adults aged between 20 and 85 living in Ontario, Canada from 2001 to 2012, using postcodes to determine a person's proximity to major roads. The cohort's medical records were examined to see who went on to develop dementia, Parkinson's disease or multiple sclerosis. Over the study period, more than 243,000 people developed dementia, 31,500 people developed Parkinson's disease and 9,250 people developed multiple sclerosis. The scientists found no link between living near a road and Parkinson's disease or multiple sclerosis, but dementia was slightly more common in people living close to busy roads and the risk dropped off gradually in less built-up areas. Those living within 50 meters of a busy road had a 7% higher risk in developing dementia, the risk was 4% higher risk at 50-100 meters, 2% higher risk at 101-200 meters and there was no increase in risk in those living more than 200 meters away. Those who lived in a major city, within 50 meters of a major road and who did not move house for the duration of the study had the highest risk at 12%.
As with almost all mainstream reporting of a medical result, they've mischaracterised the findings. What the study says is that breathing polluted air is a bad thing. One source of pollution is heavy traffic. Other sources of pollution are... well, just about anything related to commerce and industry, Also, pollution causes a lot more than dementia, Parkinson's and MS. However, if it were to be reported as "pollution is bad for you", it wouldn't make the mainstream media.
As an aside, the study is pretty well done, a cohort study of several million people over a ten-year period, nothing to fault there. It's the way it's being reported in the media that's the problem.
Maybe idiots are more pre-disposed to dementia; idiots are more likely to inhabit the cheaper housing that exists near heavy traffic.
The study looked at locations years before dementia diagnosis and attempted other controls to make it rather difficult for the causation to be backwards.
Ps, if grammar terms like subject, object, and indirect object don't come natural to you, here's one way to distinguish I, me, and myself. Replace them with he, him, and himself. Like so:
Bob found a house for himself. Sounds fine.
Bob found a house for he. Doesn't sound right.
Bob found a house for him. Still not right, if "him" means Bob.
Himself is analogous to myself, so myself is correct.
You're joking aren't you? Most of the Canadian population lives in big cities - Toronto, Montreal and Vancouver all have over 2 million people in their metropolitan areas.
People who live in cities are demented