If you like to walk for your exercise, take care where you walk. It seems that the toxic air in built-up city centres may prevent you from benefiting from any positive effects on your lungs and heart.
In a recent trial in London, it was found that the levels of black carbon, nitrogen dioxide and fine particulate matter were within healthy boundaries in Hyde Park, but breaching danger levels on Oxford Street. So, while those who walked in the park had improved lung capacity within just one hour, those who walked on Oxford Street had none. Likewise, any increase in blood flow was virtually nil for the walkers on Oxford Street. And while the arteries of those walking in the park became 24 per cent less stiff, they improved by just 4.6 per cent for those on Oxford Street. The study, published in The Lancet, found that ‘poor air quality does play an important role in the short-term benefit one can get from taking a walk.’
Not-so-fresh air
From Parish Pump