More people suffer heart attacks when air pollution levels jump
even for a short time, a large meta-analysis indicated. For each
short-term increment of 10 mcg/m3 of nitrogen dioxide, sulfur
dioxide, and so-called PM10 and PM2.5 particulates, risk of MI
for exposed individuals went up by 1% to 2.5% (P<0.01 for each),
according to Hazrije Mustafic, MD, MPH, of University Paris
Descartes in Paris, and colleagues. An even larger effect was
seen with carbon monoxide, for which each 1 mg/m3 increment was
associated with a 4.8% increase in MI risk, the researchers
wrote in the Feb. 15 issue of the Journal of the American
Medical Association. Mustafic and colleagues then calculated the
percentage of all MIs that could be attributed to short-term air
pollution exposure, or the population-attributable fraction. In
locations where everyone is exposed, these ranged from 0.6% (95%
CI 0.2% to 0.9%) for PM10s, or particulates smaller than 10
microns, to 4.5% (95% CI 2.5% to 6.5%) for carbon monoxide. But,
on the other hand