PATIENTS from deprived areas who survive heart attacks may be more likely to die subsequently partly because of exposure to air pollution, according to research published today.
The largest study yet into the impact of air pollution on heart attack victims found that higher death rates in poorer areas were linked to increased exposure to microscopic particulate matter (PM), mostly caused by traffic and industrial fumes.
Experts recorded a 20 per cent rise in deaths for every ten micrograms/m3 (metre cubed) increase in PM2.5 – minute particles measuring up to 2.5 micrometres which are about 30 times smaller than a human hair.
Dr Cathryn Tonne, study co-author and lecturer in environmental epidemiology at the London School of Hygiene and Tropical Medicine, said: “It is known that patients from poorer backgrounds often live in more deprived areas with higher levels of air pollution and that they tend to do less well after a diagnosis of heart problems than patients of a higher socioeconomic status.
“This raises the possibility that exposure to air pollution may explain, in part, the differences in prognosis among heart attack patients from different backgrounds.”
However, she added: “Our findings also show that PM2.5 exposure contributes only a small amount to differences in survival after acute coronary syndrome [heart attacks] among people living in areas with different socioeconomic conditions after accounting for factors such as smoking and diabetes.”
Air pollution is the biggest environmental threat to people’s health, with traffic fumes killing off at least ten times the number of people who die in road crashes every year.
The findings come as data shows that Scotland’s streets are still failing key air-quality standards, with levels of PM2.5 in central Glasgow measuring 43mcg/m3 yesterday, still above the 40mcg/m3 European limit.
That figure is far above the average exposures given in today’s study, which focused on patients in England and Wales.
Environmentalists renewed calls for action from authorities to reduce the “invisible killer”.
Dr Richard Dixon, director of Friends of the Earth Scotland, said: “This study shows that high pollution levels can not only send you to hospital with a heart attack, they can kill you months later, when you thought you were getting better. Councils and ministers have been ignoring this problem for a decade but this latest study shows clearly why it is essential we act to reduce pollution in our cities.”
Meanwhile, Professor Fintan Hurley, public health specialist and scientific director at the Institute of Occupational Medicine in Edinburgh, said today’s findings highlighted the damaging affects of all air pollution.
He said: “The worse the air pollution, the bigger the public health problem, but there is no safe level, so there is always a benefit in reducing pollution.”
The London study was published in the European Heart Journal.