City air pollution cancels out the beneficial effects of exercise - scientists
City air pollution can cancel out the beneficial effects of exercise in older adults, say scientists.
A London study found short-term exposure to traffic fumes greatly reduced the positive impact of walking on the heart and lungs.
For the study 119 volunteers over the age of 60 were asked to walk for two hours in a quiet part of Hyde Park and along a busy section of Oxford Street.
All the participants, recruited through London's Royal Brompton Hospital, were healthy or had a stable lung condition or non-progressing heart disease.
The study showed that all the volunteers benefited from a stroll in the park, with lung capacity improving within the first hour, arteries becoming significantly less stiff, and blood flow increasing.
In contrast walking along Oxford Street had little impact on arterial stiffness and led to only a small increase in lung capacity.
Professor Fan Chung, from Imperial College London, who led the research funded by the British Heart Foundation, said: "It is possible that studies such as this could support new air quality limits. It shows that we can't really tolerate the levels of air pollution that we currently find on our busy streets."