Most people know air pollution can hurt your lungs and make it tough to breathe. But a growing body of research shows air pollution can be as bad or worse for your heart.
"The groups of people who are most vulnerable are those already at risk for heart disease. This would include elderly individuals and also people who have other risk factors for heart disease, including people who are overweight, smoke cigarettes, people who have a poor diet -- particularly high in fat -- and people who know they have high blood pressure." says Dr. Murray Mittleman - a preventive cardiology specialist at Beth Israel Deaconess Medical Center and Harvard Medical School.
A 15-year study of people in six cities found that those who live with high pollution have higher death rates and shorter lives. Dr. Dockery Sc.D., a professor of environmental epidemiology at the Harvard School of Public Health, was part of that 1993 study and larger ones that followed. What most surprised researchers, he says, is that far more deaths are tied to heart disease than to respiratory problems.
Air pollution is most likely to affect the breathing of young children and the elderly. When it comes to the heart, those with heart problems, diabetes or the elderly are most at risk.
Air pollution's effects on the heart and blood vessels, researchers say, are a bit like the damage smoking can cause. Doctors don't know all the ways impure air affects the heart. But air pollutants:
cause blood vessels to contract.
encourage blood clots to form.
boost inflammation of blood vessels.
increase the chance that cholesterol-laden plaque will break free from artery walls.
help trigger irregular, potentially fatal heart rhythms.
When levels of particulates, ozone and other pollutants are high, there are more heart attacks, heart failure, heart disease hospitalizations, strokes and lung problems. Long-term, the American Heart Association says, living in the nation's most polluted areas could slice an estimated three years off the average life span.
A 2005 study in the journal Epidemiology found that Los Angeles residents in the most polluted inland areas had up to a 44 percent greater chance of dying of a heart attack or getting ischemic heart disease than those who live on the coast, says medical geographer Michael Jerrett, Ph.D. In ischemic heart disease, blockages starve the heart of oxygen.
"That's getting up into the range of someone who lives with a smoker," says Dr. Jerrett, the study's main author and an associate professor at the University of Southern California. "That's a big number that indicates perhaps we're not paying enough attention to air pollution as a public health risk."
What can you do?
Here's Environmental Protection Agency advice for improving our air.
Turn off unused appliances and lights.
Recycle and reuse paper bags and boxes.
Buy recycled products.
Choose products that have less packaging and can be reused.
Store paints, solvents and pesticides in airtight containers. Dispose of them properly.
Keep woodstoves and fireplaces in working order.
Purchase "Green Power" electricity, generated from renewable energy sources.
Turn your thermostat down in winter, up in summer.
Have air-conditioning systems checked in spring, heating systems in fall.
Check filters monthly.
Insulate your home, water heater and pipes.
In your car
Drive less, especially during peak traffic or on hot days.
Use public transportation, walk or ride a bike.
Shop by phone, mail or Internet.
Do your errands in one trip.
Avoid long drive-through lines. Park and go inside.
Avoid revving your engine, or idling over 30 seconds.
Use an energy-conserving (EC) grade of motor oil.
Get regular car tune-ups.
Replace your car's air filter and oil regularly.
Keep your tires properly inflated and aligned.
Get your car serviced quickly if the "check engine" light comes on.
Fill your gas tank during cooler evening hours to cut evaporation. Don't spill gas or top off your tank.