Prof 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.”
Research in this area began about 20 years ago with the discovery of brain changes in pet dogs in chronically polluted Mexico City and the finding that these changes can begin in young puppies.
Evidence accumulated over the past five years includes a study from Spain showing that air pollution can affect children’s brain development and performance in tests. Research on 1,700 Londoners showed increased mental health problems with exposure to air pollution. Last year Kelly’s Department for Health and Social Care committee reviewed 69 studies and concluded it was likely that air pollution accelerated cognitive decline in elderly people and increased the risk of developing dementia.
It is likely that damage to brain health accumulates slowly from the air pollution people breathe each day. The new report calls for an audit of existing policies to fast-track actions that reduce our exposure to air pollution through our whole lives, including low-pollution school zones and the development of dementia-friendly communities. The report also calls for health, and specifically brain health, to be part of net zero strategies.
Prof Brian Castellani of the University of Durham, director of the new report, said: “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.”