Scientists have discovered how air pollution triggers heart attacks, which cause thousands of deaths each year.
Diesel exhaust fumes increase the stress on the heart during exercise and may account for the rise in heart deaths on days when pollution from traffic fumes is high, they say.
The World Health Organisation estimates that air pollution causes 800,000 premature deaths worldwide and a recent US study suggested long-term exposure to traffic fumes increases the risk of death from heart disease and stroke by 76 per cent.
Researchers from the University of Edinburgh found that inhaling diesel fumes caused a threefold increase in stress on the heart by altering its electrical activity. The risk of blood clots was also increased.