Exposure to air pollution makes people more likely to sit or lie down and discourages physical activity, a study has revealed.
Researchers found that breathing polluted air was associated with a further 22 minutes of sedentary behaviour each day.
For the study, scientists at the National Institute for Health and Care Research and Leicester's Biomedical Research Centre monitored the physical activity of 644 people at risk of type 2 diabetes over a three-year period.
Participants wore accelerometers around their waists for seven consecutive days during waking hours, which allowed researchers to measure their daily minutes of physical activity and sedentary time. This data was analysed alongside annual average levels of particulate matter and nitrogen dioxide.
High levels of exposure to nitrogen dioxide (NO2) were associated with up to 22 minutes per day of increased sedentary time per year.
Dr Jonathan Goldney, from the University of Leicester, said: “We know that air pollution is associated with cardiometabolic and respiratory diseases, and in 2019 the World Health Organization estimated that 99 per cent of the global population breathe air containing high levels of pollutants.
“Levels of air pollution may affect people’s ability to exercise, or their enjoyment of exercise. It may also be considered a risk factor for increasing levels of sedentary behaviour by encouraging sitting time indoors and discouraging active time outdoors, further increasing the risk of chronic disease in a feedback loop.”
Higher levels of sedentary behaviour have been linked to heart disease, cancer and early death.
A study published by City Hall last year found that levels of NO2 across 14 London boroughs exceeded the UK legal limit.
Separate data published by the NHS showed that three boroughs in the capital were among the top ten areas with the highest rates of obesity among children aged 10 and 11.
Last year, Mayor Sadiq Khan expanded the Ultra low emission zone (Ulez) from central London to cover the area within the North and South Circular roads. The zone requires owners of older, more polluting vehicles to pay a daily charge of £12.50 to drive their cars.
Dr Goldney added: “If levels of air pollution are causing this increase in sedentary time, interventions to reduce ambient air pollution concentration such as low emissions zones could have a really positive impact on individual’s levels of sedentary behaviour, and a significant effect on public health.”
