Air pollution likely to contribute to diseases including dementia – committee

Air pollution is “likely” to increase the risk of developing dementia, a Government research group has said.

The Committee on the Medical Effects of Air Pollutants has published its findings after reviewing almost 70 studies which analysed how exposure to emissions affect the brain over time.

The 291-page report concludes that air pollution “likely” increases the risk of accelerated “cognitive decline” and of “developing dementia” in older people.

Experts believe this is due to the impact of pollutants entering the circulatory system, affecting blood flow to the brain.

The three other health conditions with a known link to air pollution are respiratory conditions (such as asthma), heart disease and lung cancer. Dementia has been linked to air pollution previously.

The authors of the new report said: “The epidemiological evidence reviewed fairly consistently reports associations between chronic exposure to air pollution and reduced global cognition and impairment in visuospatial abilities as well as cognitive decline and increased risk of dementia.

“Results are heterogeneous as regards to other cognitive domains such as executive function, attention, memory, language and mild cognitive impairment.

“The identified neuroimaging studies consistently report associations between exposure to air pollution and white matter atrophy.”

It adds that studies are split over which pollutant is most associated with these effects.

The committee said it has made recommendations for further research to help develop the evidence.

Around 850,000 people in the UK suffer with dementia, according to the NHS.

There is also more well-established evidence to show that exposure to air pollution increases the risk of heart disease.

Breathing in emissions can damage the blood vessels by making them narrower and harder – increasing the likelihood of clots, abnormal heart rhythms and heart attacks, according to the British Heart Foundation.

Under the Environment Act passed last year, the Government must set new targets for curbing air pollutants by October 31.

But its proposed goal for cutting annual average levels of dangerous pollutant fine particulate matter PM2.5, to 10 micrograms per cubic metre across England by 2040, is double the World Health Organisation’s new guideline limits and has drawn criticism from environmental campaigners.

Commenting on the paper, Sarah Woolnough, chief executive of Asthma and Lung UK, said: “This report is yet further evidence that the dirty air we breathe into our lungs every day has a significant impact on our health.

“Not only does it cause and trigger lung conditions like asthma, but it’s becoming ever more clear that it also contributes to dementia, lung cancer and heart disease.

“This is a public health emergency that is affecting people from the cradle to the grave.”