The researchers found that on days with high air pollution, current smokers had a greater risk of heart attack than non-smokers.

"Smokers are more sensitive to air pollution, as far as their risk for heart attacks," said study author Yves Cottin, M.D., Ph.D., of the cardiology department at the University of Dijon in Burgundy, France. "When fine particles of less than 10 micrometers (m), which are mainly attributable to diesel exhaust, exceeded 25 micrograms (g) per cubic meter, hospital admissions for heart attack rose by 91 percent in the general population and even more in current smokers."

The same may be true for other urban settings around the world, but the data needs confirmation in different geographic areas, Cottin said.

"This is yet another strong case against smoking, and a warning for high-risk people to stay indoors, or refrain from strenuous activities during peak air pollution periods. Doctors could even consider increasing heart disease treatment during those high-risk pollution times," Cottin said.

Studies have shown an association between elevated daily concentrations of environmental air pollution and higher hospital admissions for heart disease. But few studies have looked specifically at exposure to air pollution and the risk of a heart attack.

"Moreover, most of the existing studies did not separately analyze different subgroups, such as smokers versus nonsmokers," Cottin said.

Cottin and colleagues looked at data collected from January 2001 to December 2002 of 322 patients hospitalized for heart attack from the greater Dijon area. Forty-two percent were smokers.

The researchers compared the daily incidence of heart attack with the average daily concentrations in the air of particles s
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Contact: Carole Bullock
carole.bullock@heart.org
214-706-1279
American Heart Association
9-Nov-2003