Air pollution hard on hearts: MDs

Air pollution triggers as many heart attacks as drinking alcohol or coffee, and physical exertion, research suggests.

The finding points to improving air quality to prevent heart attacks, researchers said Thursday.

For the study, published in The Lancet, Belgian scientists reviewed 36 studies to rank how cocaine, alcohol use, anger and physical exertion trigger heart attacks in the general population.

"Of the triggers for heart attack studied, cocaine is the most likely to trigger an event in an individual, but traffic has the greatest population effect as more people are exposed to [it]," Tim Nawrot of Hasselt University in Diepenbeek, Belgium, and his co-authors wrote.

On an individual level, cocaine use was the riskiest, boosting heart attack risk nearly 24 times.

But at a population level, only 0.9 per cent of heart attack cases are likely triggered by cocaine.

For the general population, facing traffic was the worst trigger at 7.4 per cent, followed by physical exertion at 6.2 per cent and alcohol and coffee, both at 5.0 per cent, and air pollution at 4.8 per cent.

"Improvement of the air we breathe is a very relevant target to reduce the incidence of this disease in the general population," the study's authors concluded.

A journal editorial accompanying the study praises the study's insights on air pollution's burden on the population.

Editorial writers Andrea Baccarelli and Emelia Benjamin of Harvard's department of environmental health in Boston say if levels of fine air pollutants were decreased toward an average limit recommended by the World Health Organization, 4.8 per cent of heart attacks might be avoided or delayed.