Does air pollution make us lazy?

New research suggests that air pollution might increase an individual’s sedentary behavior by as much as 22 minutes a day, affecting fitness levels and contributing to chronic diseases.

In what is believed to be the first research of its kind, a team from  the NIHR Leicester Biomedical Research Centre has examined the relationship between the levels of background pollution people are regularly exposed to in the UK environment, and their levels of physical activity and sedentary behavior.

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% 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.’

Activity data was acquired from  from 644 participants on the Walking Away from Type 2 Diabetes trial – in which the participants wore monitors around their waists  for seven consecutive days during waking hours to give a measure of moderate-to-vigorous physical activity (MVPA) and sedentary time (SED) on three occasions over a three year period.

The team used generalised estimating equations to examine the association between long-term PM2.5, PM10 and NO₂ exposure and annual change in  SED, MVPA and steps taken.

Dr Goldney said: ‘Although the levels of pollutants we measured were not associated with a change in moderate-to-vigorous physical activity or number of steps taken, we found that they were associated with an annual increase in sedentary time.

‘An increase of 1 µg/m³ in the average concentration of atmospheric nitrogen dioxide was associated with an increase in sedentary time of 1.52 minutes per day per year in the most conservative model. And across the group, our findings suggest that high levels of exposure to nitrogen dioxide were associated with up to 22 minutes per day of increased sedentary time.

‘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.’

Little research has been undertaken into this area, although a study of 9,700 students in Beijing found that PM2.5, PM10, NO2 concentrations were associated with self-reported sedentary behaviour at a greater level than the Leicester research, possibly because of a higher levels of air pollution.

The Leicester research can be read here.