Last reviewed by Faculty of Harvard Medical School on December 20, 2010
By Thomas H. Lee, M.D.
Brigham and Women's Hospital
No one has ever made the argument that air pollution is good for you, but just how harmful is the secondhand smoke, sulfur and other particles floating around in the air? And what should you do about it? If you have an increased risk of heart disease, and live in a city with persistent bad air quality, read on to learn important information that may help you live longer.
Concern about air pollution as a cause of heart disease was heightened by a 2004 position paper from the American Heart Association. This report summarized findings from research on the cardiovascular effects of air pollutants data that should be enough to make many people with cardiovascular disease move or stay indoors, while galvanizing the rest of us to support legal steps that might help to clean up our air over time.
Research on air pollution is surprisingly difficult, because there is no single formula for polluted air. Each city and town has its own special mixture of gases, liquids and solid particles floating around in the air. So where do these harmful pollutants come from? Well, you don't need to look far. The SUV in your driveway emits fossil fuels, which are the leading contributor to air pollution in Western societies.
These pollutants dont just blacken your lungs. They increase the formation of blood clots in your arteries, which helps to cause strokes and heart attacks. They raise levels of C-reactive protein (CRP), a marker of inflammation that is a risk factor for heart disease. Research in rabbits suggests that air pollution may increase the tendency of atherosclerotic plaques to rupture, directly causing heart attacks. Other studies show that air pollutants contribute to heart-rhythm abnormalities, including sudden death.
No surprise, then, that many epidemiological studies show increased rates of heart disease in regions with the most polluted air. Studies also show that elderly people, those with underlying heart or lung disease, poorer people and diabetics are most likely to be victims. The danger is both short and long term. On days when air pollution is particularly bad, hospital admission rates go up. And people with high risk conditions living in regions with persistent, inferior air quality have higher rates of heart problems.
So what can we do? From a public policy perspective, if we got serious and achieved the National Ambient Air Quality Standards defined by the Environmental Protection Agency in 1997, we would prevent an estimated 23,000 deaths and 42,000 hospital admissions per year.
The American Heart Association statement also called attention to a website (www.epa.gov/airnow) which provides data on the severity of air pollutants in many U.S. cities each day, along with a health alert system that reflects recommended changes in activity. Next-day forecasts and real-time air-quality information about particle pollution in your city can help you to decide whether you should stay indoors or think about moving elsewhere.
You can also find air-quality forecasts and reports on particle pollution in local newspapers and in newscasts on the radio and television. If you have heart disease, diabetes, lung disease, or are elderly, these reports can help you to know when simply breathing the air outside might be hazardous to your health. Even if you dont have any of these risk factors, reducing our use of fossil fuels and cleaning up our air may one day lead to benefits for you that go beyond a view that goes on for miles.
Thomas H. Lee, M.D., is the chief executive officer for Partners Community HealthCare Inc. He is a professor of medicine at Harvard Medical School. He is an internist and cardiologist at Brigham and Women's Hospital. Dr. Lee is the chairman of the Cardiovascular Measurement Assessment Panel of the National Committee for Quality Assurance.