City Air Could Kill You

Study shows urban air pollution increases chances for lung cancer, heart disease

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HealthDay Reporter

TUESDAY, March 5, 2002 (HealthDayNews) -- City living can increase your chances of dying from lung cancer or heart disease, and the culprits are particles of air pollution so small they are virtually invisible to the naked eye.

That's the sobering finding from the largest, most definitive air pollution study to date, published in tomorrow's issue of the Journal of the American Medical Association.

The study authors contend that simply living in a major urban area exposes you to "fine particulate matter" that makes its way into your lungs when you breathe, increasing your risk of cardiopulmonary disease and cancer. Often, the risks can be as high as those for someone who is exposed to a lifetime of secondhand smoke, the researchers say.

"This means, over the long run, your lungs and heart are experiencing damage equal to what you would get if you were living with a smoker, even if you are not," says study author George D. Thurston.

Damage from cigarettes you smoke directly, however, is still much greater than anything caused by these small particles, Thurston adds.

Although much of the study doesn't say anything new, experts note it's important research because it addresses criticisms of past air pollution studies, including a lack of adequate follow-up.

"What makes this study significant is that it involved hundreds of thousands of people in cities across the country. And most importantly, it gave us nearly two decades of follow-up, during which time it continued to demonstrate a direct correlation between this fine particulate air pollution and the risk of death from heart and lung disease," says Dr. Joseph Cooke, associate director of the Medical Intensive Care Unit at New York Weill Cornell Medical Center.

The efforts to clean up city air stoke a political debate that revolves, in part, around huge power plants that continue to burn coal, and sometimes diesel fuel, to provide low-cost electricity for many suburban areas.

When that pollution is spewed into air, Thurston says, wind patterns carry it from places as far west as Ohio to cities as far east as New York and Washington. Unfortunately, these places are already compromised by vehicle pollution.

While newer plants are subject to clean air emissions laws passed during the Clinton administration, Thurston says the older companies are getting away with environmental murder, thanks to a "grandfather" clause that exempts them from the new, higher standards.

Relying on American Cancer Society data from a large ongoing study of more than 1 million people, Thurston's new research examined death records of 500,000 of those adults, followed from 1982 through 1998.

Working with researchers from the University of Ottawa, Thurston's group used a highly advanced statistical method to factor out risks that might influence results, including age, weight, diet and smoking habits. They also accounted for regional differences, as well as differences in race and sex. The final analysis separated the groups by disease -- cardiopulmonary, lung cancer and all others.

Simultaneously, they gathered data from government and other sources of levels of "small matter particulate" pollution from 51 urban centers across the United States. They then matched mortality rates with levels of pollution.

The result: For each 10-microgram elevation in "fine particulate matter," the relative risk for all-cause mortality was elevated by as much 4 percent. Deaths from cardiopulmonary disease went up 6 percent, while lung cancer mortality rose a whopping 8 percent.

As bad as things are, Thurston emphasizes that air is cleaner today than when studies began back in the early 1970s. That's due, at least in part, to improved safety limits on these tiny pollutants. According to the Environmental Protection Agency, levels should not exceed 15 micrograms per cubic meter.

While setting a limit helped, Thurston says the air city dwellers breathe isn't clean enough yet.

In New York City, for example, the average readings of "fine particulate matter" in 1999 and 2000 were still 16 micrograms (although down from 24 in previous years). In Los Angeles, it was 20 micrograms (down from 27), in Chicago, it was 18 micrograms (down from 23 ), and in Washington, D.C., it was 15 micrograms (down from 26).

What To Do

To learn more about the health risks of air pollution, visit The Environmental Defense Fund. To discover the specific risks in your city, click here and enter your zip code.

To learn more about the effects of air quality on heart and lung health, visit The American Lung Association.

SOURCES: Interviews with George D. Thurston, Sc.D, associate professor, Environmental Medicine, New York University School of Medicine, and director, Community Outreach and Education Program, NYU-NIEHS Environmental Health Center, Nelson Institute of Environmental Medicine, New York City; Joseph Cooke, M.D., pulmonologist and associate director, Medical Intensive Care Unit, New York Weill Cornell Medical Center; March 6, 2002, Journal of the American Medical Association

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