Air Pollution May be “Hard” on the Body’s Blood Vessels

Every day EPA researchers are advancing our understanding of how air pollution threatens heart health. We will be sharing some of the important studies under way and research discoveries during February in recognition of American Heart Month.

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By Ann Brown

Can air pollution affect your heart? The short answer is—yes.  It can trigger heart attacks, stroke and cause other cardiovascular health problems. The long answer is that while we know that air pollution impacts the heart, additional research is needed to learn more about how this happens and what pollutants or mixtures are responsible.

An unprecedented 10-year study funded by EPA and the National Institutes of Health, called the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air), is providing new information about the impacts of fine particle pollution on the arteries — the blood vessels that supply blood to the heart and other parts of the body. Fine particles are microscopic bits of matter that are emitted mostly from the burning of fossil fuel. They have been found to be bad for the heart, at high levels.

MESA Air is expanding our knowledge of a condition that can set you up for a heart attack—atherosclerosis. You may have heard of the term “hardening of the arteries.” Well, that refers to atherosclerosis when there is a buildup of fats, cholesterol, and calcium in and on the artery walls, most commonly known as plaque. The buildup of plaques can result in a blood clot, which can block the flow of blood and trigger a heart attack. While atherosclerosis is often considered a heart problem, it can affect arteries anywhere in your body; in the brain, it may lead to strokes.

The MESA Air study is finding evidence of associations between long-term fine particle pollution and the progression of atherosclerosis. Another important observation from the MESA Air study shows that long-term exposure to fine particle pollution limited the ability of arteries to widen when the body needs more blood flow to the heart, say, when running up a flight of stairs.

These are among the many discoveries coming out of the MESA Air study that are providing new insights into how air pollution can contribute to atherosclerosis and lead to heart attacks and strokes.

Those with heart disease who may be exposed to high levels of air pollutants can take action to protect their heart. A good first step is to be aware of high air pollution days. Check the daily air pollution forecast in your area by using the Air Quality Index at

Learn more at

About the author: Ann Brown is the communications lead for EPA’s Air, Climate, and Energy Research Program.


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