TRAFFIC FUMES RAISE RISK OF DEMENTIA

TOXIC air pollution may be increasing the risk of dementia and Alzheimer’s disease, a study claims.

Researchers in America have found that elderly women living in areas where fine-particle air pollution exceeded health standards were nearly twice as likely to develop dementia.

Women who already had high genetic predisposition for Alzheimer’s faced a 263 per cent increased risk.

The findings from the health data of 3,647 women, aged 65 to 79, in the US from 1999 to 2010, revealed pollution could be responsible for up to 21 per cent of dementia cases in America and could have implications for smog-ridden UK cities.

Caleb Finch, co-author of the study and a professor at the USC Leonard Davis School of Gerontology, warned: “Our study has global implications as pollution knows no borders.”

The British government has repeatedly been taken to court over its failure to meet EU standards on air pollution and has admitted it might not meet the rules in London and some other cities until 2025, which is well after Brexit.

The report studied the effects of diesel soot from car and truck exhausts and other fine particle pollution consisting of chemical compounds and toxic airborne specks just 2.5 microns in diameter, or about 1/28th the width of a human hair.

Exposed

The particles are so tiny they can move from the blood stream through cell walls and enter the brain. This triggers an immune response and the formation of toxic sticky plaques, which leads to the decline in brain function and ends in death.

People living near motorways, ports and depots are exposed to higher amounts of particle pollution from diesel exhausts.

Earlier studies have blamed this kind of air pollution for early deaths, heart disease, stroke, and reduced lung function in children. Dr James Pickett, at the Alzheimer’s Society said: “This study is one of several that links air pollution with increased risk of dementia. Together they suggest tackling air pollution may be one way to reduce future cases of the condition.”

Dr Jiu-Chiuan Chen, of the University of Southern California and study co-author, said the results showed health standards globally for particle pollution may not be tough enough.

“We don’t know if the health goal is providing a safe margin for those with greater risk. This is something policymakers need to be aware of,” he said.

Dr Chen added none of the women in his study, published in Translational Psychiatry, had dementia before they enrolled.

His team also examined the brains of female mice carrying genes linked to Alzheimer’s. They were exposed to fine-particle air pollution for 15 weeks.

Results showed they were 60 per cent more likely to have amyloid plaques linked to Alzheimer’s in their brains when compared to mice not exposed.