Pollution cancels out the benefits of exercise for adults aged 60 and above, a joint study suggests.

Even just a few hours in a polluted street and any benefits of having exercised can be wiped out, says a study from Duke University and Imperial College London.

The study, published in The Lancet, compared the effects of walking in polluted areas and greener areas such as parks, especially among adults aged at least 60 years.

In the study, 119 participants 60 and above walked for two hours during midday in two different London areas, the Hyde Park and the Oxford Street. Participants either have stable heart diseases and COPD or were healthy.

Researchers noted that black carbon, nitrogen dioxide and fine particulate matter from diesel exhaust fumes in Oxford Street exceed air quality limits set by the World Health Organization (WHO). The participants also had their physical measurements taken before and after the activity.

The result, as expected, leaned towards the benefits of walking in greener areas.

“Our research suggests that we might advise older adults to walk in green spaces, away from built-up areas and pollution from traffic,” said author Professor Fun Chung, of the Respiratory Medicine and Head of Experimental Studies Medicine at the National Heart and Lung.

In Hyde Park, participants’ lung capacity improved significantly for the first few hours and lasted for more than 24 hours, whereas there was little gain in walking on Oxford Street.

Walking in Hyde Park also resulted in arteries becoming less stiff up to 24 percent among healthy and COPD participants.

However, “this effect was drastically reduced when walking along Oxford Street, with a maximum change in arterial stiffness at just 4.6 percent for healthy volunteers, 16 percent for those with COPD and 8.6 percent for heart disease,” according to a release from Imperial College.

“This adds to the growing body of evidence showing the negative cardiovascular and respiratory impacts of even a short, two-hour exposure to motor traffic pollution,” says Professor Junfeng Zhang of Duke University.

The authors note that the findings should be considered in urban planning as those aged 60 and above might only have “walks” as their form of exercise.

“It is possible that studies such as this could support new air quality limits, as it shows that we can’t really tolerate the levels of air pollution that we currently find in our busy streets,” said Professor Chung. MIMS