Those over 60 should stick to green spaces and parks when they go for a walk and avoid the streets of the city, according to a pioneering study that says air pollution from traffic gases eliminates the benefit to a large extent Exercise health.  Walking is often recommended for older people, but the study of Imperial College London and Duke University in the USA. UU It suggests that those over 60 and those with pulmonary and cardiac problems should stay away from urban areas with heavy traffic. The negative effect may be the same in younger people, say the authors, and reinforces the urgency of reducing emissions on city streets.
The research compared walking for two hours on Oxford Street with a stroll through Hyde Park, which records some air pollution, but much less than in the heart of the capital city's business district.
Researchers enrolled 119 healthy people with stable heart disease or stable COPD (chronic obstructive pulmonary disease) that damages the lungs. They were randomly assigned to walk on the west end of Oxford Street, which is restricted to taxis and buses that emit diesel fumes and has frequently violated air quality limits set by the World Health Organization or a traffic-free area. from Hyde Park. A few weeks later they made the other walk. The findings were published in the medical journal Lancet.
Noise and pollution levels were significantly higher at Oxford Street, including higher levels of black carbon, nitrogen dioxide and fine particles. All participants benefited from a walk in the park, with improved lung capacity in the first hour and a significant and lasting increase for more than 24 hours in many cases. In comparison, a walk up and down Oxford Street produced only a small increase in lung capacity in the participants, much lower than that recorded in the park.
Blood flow also increased after exercise, with decreases in blood pressure and an increase in heart rate. The arteries became less rigid in people walking in Hyde Park, with a maximum change since the beginning of the study of more than 24% in healthy volunteers and with COPD, and more than 19% in patients with heart disease.
However, this effect was drastically reduced when walking on Oxford Street, with a maximum change in arterial stiffness of only 4.6% for healthy volunteers, 16% for those with COPD and 8.6% for heart disease.
These findings are important, since walking is recommended frequently for the elderly. "For many people, like the elderly or those with chronic illnesses, very often the only exercise they can do is walk," said Kian Fan Chung, a professor of respiratory medicine at Imperial's National Heart and Lung Institute and lead author. of the study. "Our research suggests that we could advise older adults to walk in green spaces, away from urbanized areas and traffic pollution," he added.
Chung said that traffic pollution could also affect younger people who shop in the heart of a city.
"I think it could very well be, the only difference is that young people are much more resistant," he said. A study of younger people should be done, he said.
Other scientists said that the study was important evidence of air pollution damage, although they would not advise people to stop walking on city streets, because the benefits for healthy people were reduced, but not completely lost.
Ian Colbeck, professor of environmental science at the University of Essex, said the document highlighted health risks by walking along polluted roads, for those over 60 with specific pre-existing medical conditions.
"We know from other research that for the vast majority of the population the benefits of any physical activity far outweigh any damage caused by air pollution, except for the most extreme concentrations of air pollution," he said. "It is important that people continue to exercise, and in the UK, physical inactivity is the fourth leading cause of illness and death and contributes to about 37,000 premature deaths in England each year."
Professor Stephen Holgate of the University of Southampton and special adviser to the Royal College of Physicians on air quality, said: "The observation that air pollution found on a London street eliminates any protection of health produced The outdoor exercise is yet another demonstration that pollution is eroding the health of ordinary people.More than that, it would seem that pollution, largely related to traffic emissions, has an immediate adverse effect on people. with chronic diseases such as COPD and cardiovascular diseases.
"Although medication for cardiovascular diseases apparently protects against the acute effects of pollutants, is this the way we should face the problem? I would say not. This important study calls for actions to radically reduce pollution at the source to allow our cities and towns to be safe places to live and move. "