EPA’s MESA Air Study Confirms that Air Pollution Contributes to the #1 Cause of Death in the U.S.

air pollution and health, air research, cardiovascular health, MESA Air Study 1 Comment

By Dr. Wayne Cascio

This week we took a giant leap forward in our understanding of the relationship between air pollution and heart disease with the publication of results from the Multi-Ethnic Study of Atherosclerosis Air Pollution Study (MESA Air) in the leading medical journal The Lancet.

Fat accumulation in the wall of a coronary artery

For more than two decades, scientific evidence has shown fine particle pollution (PM_2.5) in the outside air is a cause of cardiovascular illness and death, and has justified improving the PM_2.5 annual National Ambient Air Quality Standard to protect public health. Yet, MESA Air was the first U.S. research study to examine a group of people over a period of 10 years and measured directly how long-term exposure to air pollution contributes to the development of heart disease and can lead to heart attacks, abnormal heart rhythms, heart failure, and death. MESA Air did just that, and Dr. Joel Kaufman, the leader of MESA Air at the University of Washington and his colleagues should be commended for their accomplishment.

MESA Air was funded by EPA and made possible by the National Heart, Lung, and Blood Institute, which supports a larger study on atherosclerosis called MESA. The additional air pollution study had the ambitious goal of seeking an answer to the question of whether long-term exposure to PM_2.5 and nitrogen oxides (NO_x) was associated with the development and progression of cardiovascular disease. A total of 6,800 people with diverse racial and ethnic backgrounds and residing in six locations throughout the country agreed to participate in the decade-long study by researchers at the University of Washington who received the grant. And the results are in!

The researchers used computerized tomography imaging to measure coronary artery calcium content in the same person repeatedly during the study as an indication of coronary artery disease. The results showed that long-term exposure to PM_2.5and NO_x increased coronary artery calcium. The increase observed is at a rate that, over the period of the study, would change the risk of heart attack in some.

This study is extraordinary in many ways. First it provides the strongest evidence yet that air pollution can and does contribute to cardiovascular disease–the number one killer of Americans and people in developed countries throughout the world. Secondly, the results define the relationship between air pollutants and the progression of coronary artery disease over time. This relationship will help estimate the long-term health impacts and economic burden of air pollution within our population. And, third the study shows the power of intra-agency cooperation to conduct valuable and cost-effective science.

The findings of MESA Air will continue to reverberate throughout the environmental science and public health communities for some time, but it’s time for healthcare providers, air quality managers and state and local planners to take note and to begin to consider long-term exposure to air pollution as having long-term health implications, even at levels near the National Ambient Air Quality Standards.

About the Author: Dr. Wayne Cascio spent more than 25 years as a cardiologist before joining EPA’s Office of Research and Development where he now leads research on the links between exposures to air pollution and public health, and how people can use that information to maintain healthy hearts.

Editor's Note: The opinions expressed herein are those of the author alone. EPA does not verify the accuracy or science of the contents of the blog, nor does EPA endorse the opinions or positions expressed. You may share this post. However, please do not change the title or the content. If you do make changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

Feb 11, 2014

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

Air Now, air pollution and health research, air quality, Air Quality Awareness, air research, atherosclerosis, cardiovascular health, Clean Air Act, healthy heart, Healthy Hearts, heart attack, MESA Air Study, stroke 0 Comments

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.

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 www.airnow.gov.

Learn more at epa.gov/healthyheart.

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