Health & Wellness

Living by a Highway May Boost Dementia Risk

Researchers have found a link between neurological disorders such as dementia and living near major roads and highways

Photo: iStock/mikeinlondon.

Neurological disorders such as multiple sclerosis, Alzheimer’s diseases, and Parkinson’s disease are more common among those living close to major roads and highways, according to a new study from researchers at the University of British Columbia.

The study, published in the journal Environment Health, looked at 700,000 adults living in the Metro Vancouver area between 1999 and 2003, analyzing residents’ hospital records, prescription history, and history of doctor visits. The researchers also considered what residents’ exposure to noise and air pollution would be based on their postal codes.

Researchers found that those living near major roads or highways were seven times more likely to have Parkinson’s disease and 14 times more likely to be diagnosed with non-Alzheimer’s dementia. On the other hand, those living near greenery and pubic parks were found to have three to eight per cent less risk for neurological disorders.

Those living close to a major road lived within 50 metres of the road, while those living close to highways lived no less than 150 metres away. Those living near parks and greenery lived no less than 100 metres away from them.

Researchers found no correlation with noise pollution.

Researchers caution that the study shows a correlation between neurological disorders and one’s environment, not causation. Factors such as income and education were accounted for, but only to a limited extent, with researchers lacking data on each individuals’ socio-economic status.

“Due to data availability we were unable to account for certain lifestyle or behavioral risk factors, like smoking and physical activity,” the authors of the study also wrote.

“As is common in such large cohort analyses, these exposure estimates did not fully represent personal exposures as they did not account for individual factors, like time spent at home and travelling patterns, or exposures encountered indoors.”