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Study finds foul air can trigger heart attacks
June 11, 2001 Posted:
4:25 PM EDT (2025 GMT)
From Rhonda Rowland
CNN Medical Unit
ATLANTA, Georgia -- Studies
already suggest that bad air can contribute to a number of health
threats, including asthma attacks and lung and heart disease.
Now there's evidence that as
pollution increases, so do your chances of a heart attack, according
to a study in the American Heart Association journal Circulation.
Within just two hours of breathing in
fine particles from a city's bad air -- caused by vehicle exhaust
and smokestacks, among other factors -- the risk of a heart attack
increased 44 percent. A full day after exposure, heart attacks
increased overall by one-third.
"We were able to look at an
hour-by-hour basis and what we found, as a result, was that in fact
the risk of a heart attack seems to go up very shortly after high
increased levels of fine particles," said Dr. Murray Mittleman,
director of cardiovascular epidemiology at Beth Israel Deaconess
Medical Center in Boston, Massachusetts.
Researchers interviewed 772
Boston-area heart attack survivors a few days after they were
admitted to the hospital, to determine when their symptoms began,
then compared the data to air pollution measurements.
"I was surprised that with such
a relatively small sample of individuals they were able to see this
kind of effect that they did see, which says to me that we are
probably measuring something real," said Dr. Frank Spiezer of
Harvard Medical School.
High-risk people should take
precautions
Researchers used air-quality
measurements collected from monitoring stations throughout the
Boston area.
"We now know for very low
concentrations, concentrations below the national air quality
standards, we still can detect effects of air quality on
humans," said Petros Koutrakis of the Harvard School of Public
Health.
Because they're so small, the
particles can bypass the body's normal defense mechanisms and go
deep into air sacs in the lungs, triggering an inflammatory
response, researchers told Reuters.
This bad air is not just found in big
cities. Weather patterns can send it hundreds of miles away, and it
can vary dramatically from day to day.
While the conditions may not pose a
big threat to young, healthy people, those who are at high risk for
heart disease should avoid spending a lot of time outdoors on those
hot, humid, hazy days, researchers say.
And when indoors, people should try
to keep the bad air out by using air conditioning and making sure
air filters are clean
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