COULD POLLUTION BE LINKED TO BRAIN DECLINE?

AIR pollution was added to the list of modifiable factors to reduce dementia by the Lancet Commission in 2020.

This follows studies, including one in Canada of 6.6 million people, that have shown living on a main road is associated with a higher risk of dementia.

Those living within 50 metres of a major road were 7 per cent more likely to develop dementia than people living more than 300 metres away, where fine particulate matter levels [the particles of pollution that can get into the bloodstream] can be up to ten times lower. Dr Tom Russ, a consultant psychiatrist and honorary clinical senior lecturer at the University of Edinburgh, says: ‘I make a conscious effort to avoid walking along main roads and find back street routes where possible.’

‘Pollutant distribution depends on weather conditions, though,’ says Dr Russ.

Heatwaves and high pressure, for instance, can create stagnant air and pollutants are not dispersed — and winds can distribute pollutants over a wide area.

‘There are questions that remain unanswered about pollution and the brain, though,’ says Dr Russ. ‘One is whether pollution is just a subtle effect on your thinking skills or does it have a structural effect on the brain.’

There is some suggestion that pollution contributes to brain inflammation, adds Gill Livingston, a professor of mental health in older people.

‘It’s why it is also important to try to get away from pollution as much as possible, by spending leisure time or doing exercise in parks or in the countryside.’ She also avoids exposure to wood fires and passive smoking as both produce particulate matter.