Exercise can reverse harmful effects of air pollution

If you avoid morning walks owing to fears related to the bad quality of air, start afresh as researchers from University of Copenhagen have found that exercise can outweigh the harmful effects of air pollution.Despite the adverse effects of air pollution on health, air pollution should not be perceived as a barrier to exercise in urban areas, they added.

"Even for those living in the most polluted areas of Copenhagen, it is healthier to go for a run, a walk or to cycle to work than it is to stay inactive," said Zorana Jovanovic Andersen, associate professor from the Centre for Epidemiology and Screening in a paper published in the journal Environmental Health Perspectives.The Danish study included 52,061 people, aged 50-65 years, who participated in the cohort study Diet, Cancer and Health. They reported on their physical leisure activities, including sports, cycling to/from work and in their leisure time, gardening and walking.

The researchers then estimated air pollution levels from traffic at their residential addresses. The team observed about 20 per cent fewer deaths among those who exercised than among those who did not exercise -- even for those who lived in the most polluted areas or close to busy roads and highways.Air pollution is often perceived as a barrier to exercise in urban areas."In the face of an increasing health burden due to rising physical inactivity and obesity in modern societies, our findings provide support for efforts in promoting exercise, even in urban areas with high pollution," Andersen added.

"However, we would still advise people to exercise and cycle in green areas, parks, woods, with low air pollution and away from busy roads, when possible," she noted.It is well known that physical activity reduces while air pollution increases the risk of premature mortality. This is the first large population-based, prospective cohort study that has examined the joint effects of both physical activity and air pollution on mortality, the authors concluded.

(The study published in the journal Environmental Health Perspectives)