BOSTON, MA – Depending on your size and activity level, you inhale between 3,000 and 6,000 gallons of air each day. Manufacturing, transportation, electricity generation, and other human activities spew a bewildering array of pollutants into that air. These pollutants aren't just a problem for the lungs. They turn out to be just as bad — if not worse — for the heart and circulatory system, explains the August issue of the Harvard Heart Letter.

On days when air pollution levels are high, there are more heart attacks and hospitalizations for heart disease, stroke, heart failure flare-ups, and lung trouble. Air contamination also has long-term effects on heart health, reports the Harvard Heart Letter. A long-term Harvard study begun in the mid-1970s showed one important effect of chronically breathing polluted air: additional early deaths due to cardiovascular disease. Recently, a group from the University of Southern California showed another — more atherosclerosis, the process that leads to cholesterol-clogged arteries. Among residents of the Los Angeles Basin, those living in areas with the highest average level of fine particulates in the air had thicker carotid arteries (a sign of more atherosclerosis) than those living in less polluted areas.

The Harvard Heart Letter recommends that if you have heart disease, diabetes, or lung problems, or are in poor health, you should check the air quality before going outside, much as you might check the weather. Some states or regions even have air quality alert programs that automatically send you an e-mail message or fax when poor air quality is predicted in your area.

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