How does air pollution affect health? Reducing dementia risk should be part of clean air strategies

Protecting brain health should form part of net-zero strategies, advised the Inspire report  (Jeremy Selwyn)
Protecting brain health should form part of net-zero strategies, advised the Inspire report (Jeremy Selwyn)

Air pollution is harming our brain health, mental health and leading to an increased risk of dementia, according to a report from InSPIRE – a UK policy and research consortium.

The research stated that action should be taken to reduce exposure to pollution, with brain health to be included in net zero strategies.

Here are the key details.

What does the evidence say?

The research has been under way for 20 years. It started with the discovery of brain changes in pet dogs in the heavily polluted Mexico City, and revealed that these changes can begin in young puppies.

Over the past five years, evidence has mounted. For example, a study from Spain revealed that air pollution can hinder children’s brain development and performance in tests.

Then, when research was undertaken on 1,700 Londoners, it revealed those exposed to air pollution had increased mental health problems.

Speaking to the Guardian, Professor Frank Kelly of Imperial College London, a former chair of the UK Committee on the Medical Effects of Air Pollution, said: “Dementia is one of the greatest, if not the greatest, global challenge for health and social care in the 21st century. Recognition that air pollution might accelerate the decline in cognitive function and contribute to the development of dementia came as a surprise when such an association was first postulated.

“Logic suggested that air pollution would affect our lungs, then research found that circulatory diseases were also affected by poor air quality. It didn’t take long for researchers to ask if other organs like the brain were affected as well.”

Last year, Kelly’s committee, which comes under the Department of Health and Social Care, reviewed 69 studies and found it was likely that air pollution increased cognitive decline in elderly people, as well as increasing the risk of developing dementia.

It is thought brain health damage accumulates slowly from the air pollution people breathe each day.

What needs to be done to tackle the problem?

The report demanded an audit of the policies that exist at the moment, to fast-track actions that reduce our exposure to air pollution throughout our lives. These include low-pollution school zones and the development of dementia-friendly communities. It also suggested that health, and specifically brain health, should be part of net zero strategies.

Professor Brian Castellani of the University of Durham, the director of the report, told the Guardian: “A major step change is improving urban life, for example road congestion, green spaces, indoor air quality, ultra-low emission zones, biking and pedestrian lanes, as well as tackling health and economic inequalities.

“We also need policies to recognise that even legal limits of air pollution can be harmful and potentially worsen the situation of people living with dementia, neurodegenerative disease or early life brain health issues.”