FOR IMMEDIATE RELEASE
March 23, 2009
Contact: Donna Krupa
Office: (301) 634-7253
commoff@the-aps.org
Inhaling A Heart Attack:
How Air Pollution Can Cause Heart Disease
 BETHESDA,
Md. (March 18, 2009) We are used to thinking of heart disease as a
product of genetic factors or lifestyle choices, such as what we eat and how
much we exercise. There is another road to heart disease: breathing.
Accumulating evidence indicates that an increase in
particulate air pollution is associated with an increase in heart attacks
and deaths. Research has begun in the relatively new field of environmental
cardiology -- a field that examines the relationship between air pollution
and heart disease.
Aruni Bhatnagar of the University of Louisville and
Robert Brook of the University of Michigan have organized a symposium
Environmental Factors in Heart Disease, to take place April 21 at the
Experimental Biology conference in New Orleans. The American
Physiological Society is one of the sponsors of the annual conference.
Dr. Bhatnagar will speak on Environmental aldehydes exposure and
cardiovascular disease, while Dr. Brook will give a talk on
Environmental pollution and hypertension. In addition, Araujo Jesus of
UCLA will speak on Exacerbation of experimental atherogenesis by
ultrafine air pollution, and Murray Mittleman of the Harvard School of
Public Health will speak on Air pollution and stroke.
There have been a number of studies connecting
pollution with heart disease:
-
A study of six U.S. cities found that people died earlier
when they lived in cities with higher pollution levels. A majority of
these deaths were due to heart disease.
-
A study of 250 metropolitan areas around the world found a
spike in air pollution is followed by a spike in heart attacks.
-
A study in Salt Lake City found that when a nearby steel
mill shut down for a period of months, there was a 4-6% drop in
mortality. The mortality rose to previous levels when the steel mill
reopened.
The people who seem to be most susceptible to
environmental pollutants are the people who are already vulnerable,
including the elderly and people with coronary artery disease. There is also
some evidence that diabetics, women and people who are obese may be at
greater risk.
Identifying harmful pollutants
Researchers are trying to find out which pollutants are
harmful and how the harmful pollutants work to damage the cardiovascular
system. They have focused on smaller, microscopic particles that can get
into the lungs and may gain entrance to the blood stream. (The upper airway
filters out larger particles that are in smog and other air pollutants
before they can cause a problem.)
In addition, researchers have focused on air
pollutants, including:
-
ozone
-
nitrates
-
sulfates
-
metals
-
aldehydes
One intriguing statistic is that the risk of heart
attack increases in parallel with time spent in traffic the previous day. In
animal experiments, Dr. Bhatnagar has found that aldehydes -- a toxic class
of chemicals found in most forms of smoke, including cigarette smoke and car
exhaust -- increase blood cholesterol levels and activate enzymes that cause
plaque in the blood vessels to rupture. When plaque ruptures, it can cause a
blood clot, which may block an artery and lead to a heart attack.
Much of Robert Brook’s research has centered on the
relationship between air pollution and hypertension. Fine- and ultra-fine
particles that get into the lung may make their way into the blood vessels.
Within 15 minutes of inhaling pollutants, there is a very rapid increase in
blood pressure, he said.
Blood vessels react to the pollutants by producing an
inflammatory response to attack the foreign matter. However, the
inflammatory response itself can set off a complex physiological reaction
that is harmful to the blood vessels, Dr. Brook said.
Lessons learned
If you live in an area where pollution levels may be
high, you can take steps to reduce the risk of air pollution, Dr. Brook
said. During times when air quality is unhealthy, exercise indoors, because
indoor air is filtered. If you exercise outdoors, particularly if you’re at
risk for heart disease, do it when pollutants are at lower levels. Avoid
peak traffic times.
The work in environmental cardiology goes on and these
researchers, and others, will gather together at Experimental Biology to
share their ideas and research findings and plan the next steps in fighting
environmental heart disease.
Editor’s Notes: To arrange an interview with Dr.
Bhatnagar or Dr. Brook, please contact Donna Krupa at
commoff@the-aps.org or (301) 634-7253.
A fuller audio interview is available in Episode 17 of
the APS podcast, Life Lines, at:
http://media.libsyn.com/media/lifelines/Episode_17_Environmental_Cardiology.mp3.
You can also find out more about the symposium at:
http://www.the-aps.org/meetings/eb09/abs/cvs-bhatnager.htm.
Physiology
is the study of how molecules, cells, tissues and organs function to create
health or disease. The American Physiological Society (APS) has been an
integral part of this scientific discovery process since it was established
in 1887.
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