Living close to a busy road increases the risk of Alzheimer’s and other forms of dementia by
up to 12%, a major study has found.
Scientists in Canada found a clear trend after tracking the progress of more than six million adults for 11 years.
People living within 50m of heavy traffic had a 7% higher risk of developing dementia compared with those whose homes were more than 300m away.
The increased risk fell to 4% for those living 50-100m from a busy road and to 2% between 101-200m. Beyond 200m there was no
evidence of a link.
For people living in a major city, who never moved from a home within 50m of a busy road, the dementia risk was increased by as much as 12%.
The findings are backed up by recent studies suggesting that long-term exposure to two common traffic pollutants – nitrogen dioxide and sooty particles generated by diesel engines – may contribute to brain shrinkage and mental impairment.
Lead scientist Dr Hong Chen, from Public Health Ontario, said: “With our widespread exposure to traffic and the greater tendency for people to live in cities these days, this has
serious public health implications.
“Increasing population growth and urbanisation has placed many people close to heavy traffic, and with widespread exposure to traffic and growing rates of dementia, even a modest effect from near-road exposure could pose a large public health burden.”