Everyone who considers buying a property near a main road considers the noise problem, but there are worse things to take into count and it has now been strongly linked in a report in The Lancet to higher rates of dementia. Scientists have already found that heavy snoring at night and intense sleepiness during the day are strongly linked to traffic pollution.

Air pollution has also been shown to increase the risk of snoring, lung cancer, heart disease and asthma and causes 40,000 deaths in Britain annually.

Dementia is a major world problem and growing in severity. At the moment there are 50 million diagnosed cases but the causes that rob people of their memories and brainpower are not yet clearly understood.

People living near major roads have higher rates of dementia, the research published in the Lancet suggests. The researchers who followed nearly 2m people in Canada over 11 years, say air pollution or noisy traffic could be contributing to the brain’s decline. About 10% of cases in people living within 50m of a major road could be down to traffic, the study suggests.

Dementia experts in the UK said the findings needed further investigation but were “certainly plausible”.

The study in the Lancet followed nearly two million people in the Canadian province of Ontario, between 2001 and 2012. There were 243,611 cases of dementia diagnosed during that time, but the risk was greatest in those living closest to major roads.

More than ten million Britons are at a higher risk of dementia because they live near a busy road, scientists have concluded. Those living in big cities were up to 12 per cent more likely to develop dementia as a result of traffic fumes, according to a study of more than six million people. The risk increased with proximity to heavy traffic.

The scientists said that their findings were “of real public health significance” and the results would increase pressure for tougher curbs on pollution. More than 200,000 people a year develop dementia in Britain. One in ten cases in people living near busy city streets could be explained by pollution, according to researchers, who call for homes to be built further from traffic.

“This is an important paper,” says Prof Martin Rossor, the UK’s National Institute for Health Research director for dementia research. He added: “The effects are small, but with a disorder with a high population prevalence, such effects can have important public health implications.”

Prof Tom Dening, the director of the Centre for Dementia at the University of Nottingham, said: “It is certainly plausible that air pollution from motor exhaust fumes may contribute to brain pathology that over time may increase the risk of dementia, and this evidence will add to the unease of people who live in areas of high traffic concentration.

Compared with those living 300m away from a major road the risk was 7% higher within 50m, 74% higher between 50-100m but only 2% higher between 101-200m. The analysis suggests 7-11% of dementia cases within 50m of a major road could be caused by traffic.

One of the report authors from Public Health Ontario, said: “Increasing population growth and urbanisation have 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.

Our previous research was published in September last year, and demonstrates that snoring is linked to earlier onset of cognitive impairment such as dementia and Alzheimer’s and this new research underlines it.

It’s an expensive long-term task to lower areas of strong air pollution – but not to stop snoring. It’s fast, and can even be achieved overnight in many cases, can be easily done, and costs next to nothing.

SleepPro Stop Snoring products are medically approved, and not just recommended by the National Health Service, but many Hospitals and Sleep Centres supply them directly to patients in most need. Other patients are put in touch online and given the SleepPro Stop Snoring literature that covers the range of products with prices that are affordable everyone. These range from under $39 to just over $150 according to the type of appliance needed and the degree of the problem’s severity.