September 21, 2011
Pollution Increases Heart Attack Risk
According to a study published in the British Medical Journal, high levels of pollution could increase the risk of having a heart attack for up to six hours after exposure.
U.K. researchers reviewed 79,288 heart attack cases from 2003 to 2006 and exposure to pollution levels by the hour.
Krishnan Bhaskaran, an epidemiologist from the London School of Hygiene and Tropical Medicine, and colleagues used the U.K. National Air Quality Archive to investigate the levels of specific pollutants in the atmosphere.
The team included pollutant particles, carbon monoxide, nitrogen dioxide, sulphur dioxide and ozone. Pollutant particles and nitrogen dioxide are related to traffic pollution.
The authors found no increase in heart attack risk after the six-hour window.
The team said there may be "limited potential for reducing the overall burden of myocardial infarction through reductions in pollution alone, but that should not undermine calls for action on air pollution, which has well established associations with broader health outcomes including overall, respiratory and cardiovascular mortality."
Professor Richard Edwards and Dr Simon Hales from the University of Otago in New Zealand said in an editorial accompanying the study that "despite the strengths of the study, it is possible that a true effect was missed because of imprecise measurements and inadequate statistical power."
The researchers conclude that "given other evidence that exposure to air pollution increases overall mortality and morbidity, the case for stringent controls on pollutant levels remains strong."
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