Short-term rises in
air pollution might trigger heart attacks – especially among
smokers – according to a study presented at the American Heart
Association’s Scientific Sessions 2003.
found that on days with high air pollution, current smokers had
a greater risk of heart attack than nonsmokers.
“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,
particles of less than 10 micrometers (µm), which are mainly
attributable to diesel exhaust, exceeded 25 micrograms (µg) per
cubic meter, hospital admissions for heart attack rose by 91
percent in the general population and even more in current
The same may be
true for other urban settings around the world, but the data
needs confirmation in different geographic areas, Cottin said.
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.
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.
of the existing studies did not separately analyze different
subgroups, such as smokers versus nonsmokers,” Cottin said.
colleagues looked at data collected from January 2001 to
December 2002 for 322 patients hospitalized for heart attack
from the greater Dijon area. Forty-two percent were smokers.
compared the daily incidence of heart attack with the average
daily concentrations in the air of particles smaller than 10µm
(PM10). They also measured average
levels of ozone, sulfur dioxide, nitrogen dioxide and carbon
included the ATMO index, widely used in France as a daily
overall indicator of air quality. The index ranges from one to
10, where one indicates very good and 10 very poor. It is
calculated via the daily monitoring of four pollutants, both
gases and particles (nitrogen dioxide, sulfur dioxide, ozone and
levels in Dijon remained under four on the ATMO index 86 percent
of the time. While the pollution level rose to six or higher
only about 5 percent of the time, or about 18 days a year, heart
attacks were 161 percent more likely to occur in the general
population and 250 percent more likely in smokers during those
separately, ozone, sulfur dioxide and nitrogen dioxide did not
cause measurable detrimental effects, Cottin said.
However, the researchers found that particulate matter increased
the risk of heart attack, even at levels lower than current
Studies are under
way to follow up with the patients who had heart attacks during
the study period to analyze any differences that might exist
between heart attacks people have during peak air pollution
times versus cleaner air days.
Clotilde Royer, Marianne Zeller, Jean-Pierre Besancenot,
Jean-Claude Beer, Mohamed Jolak, Gilles Dentan, Luc
Janin-Manificat and Jean-Eric Wolf.