Although exercise is recommended for people who are rehabilitating from a heart attack, new research suggests that you’d probably want to try and steer clear of busy roads while you’re doing it. Scientists at the University of Edinburgh and Umea University in Sweden have measured the effects of diesel exhaust fumes on heart and blood vessel function in twenty men who’d previously had a heart attack. Each man was put on an exercise bike, and given either clean or polluted air to breathe. The team found that breathing in the fumes caused changes in the heart’s electrical activity. This suggests that air pollution reduces the amount of oxygen that can get to the heart during exercise. In addition, the researchers found that the body’s ability to make a “guardian” protein known as t-PA, which can prevent blood clots from forming, was also reduced by more than a third following exposure to the fumes.
In fact, this explains why previous studies have found that patients with heart disease are more likely to be admitted to hospital on days in which air pollution levels are high. And it also reveals that as well as affecting our lungs, traffic fumes can have a major effect on our hearts too. The research is particularly relevant for people in areas with lots of diesel-powered traffic. Diesel engines produce 10 to 100 times more pollutant particles than petrol engines, and the number of diesel-powered automobiles is increasing in Europe and other parts of the world. Perhaps in the future, we could see the introduction of devices that can filter out harmful particles from exhaust gases. This might help to improve heart and lung health for us all.
But if you’re a heart patient – or know someone who is – then it’s probably worth steering clear of busy roads if you’re out exercising. The medical director of the British Heart Foundation, Professor Peter Weissberg, says that “Because of the overwhelming benefits of exercise on heart health, we would still encourage heart patients to exercise regularly, but preferably not when there is a lot of local traffic around. Heart patients can look out for pollution levels on their local weather forecasts.”