Risky City Air?

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http://cbsnews.cbs.com/stories/2002/03/05/health/main503073.shtml

Risky City Air?

CHICAGO, March 6, 2002

We've all heard about the risks of sidestream smoke - smoke from someone

else's cigarette or pipe.

But how about the risk to your lungs from air pollution?

A study in the Journal of the American Medical Association says long-term

exposure to the air pollution in some of America's biggest metropolitan

areas significantly raises the risk of dying from lung cancer and is about

as dangerous as living with a smoker.

The study echoes previous research and provides the strongest evidence yet

of the health dangers of the pollution levels found in many big cities and

even some smaller ones, according to the researchers from Brigham Young

University and New York University.

The risk is from what scientists call combustion-related fine particulate

matter - soot emitted by cars and trucks, coal-fired power plants and

factories.

Researchers studied 500,000 adults who enrolled in 1982 in an American

Cancer Society survey on cancer prevention. The researchers examined

participants' health records through 1998 and analyzed data on annual air

pollution averages in the more than 100 cities in which participants lived.

The researchers first took into account other risk factors for heart and

lung disease such as cigarettes, diet, weight and occupation.

Lung cancer death rates were compared with average pollution levels, as

measured in micrograms per cubic meter of air. The researchers found that

the number of lung cancer deaths increased 8 percent for every increase of

10 micrograms. Other heart- and lung-related causes of death increased 6

percent for every 10-microgram increase.

Dearry, a scientist at the National Institute of Environmental Health

Sciences, which funded the study, called it " the best epidemiologic evidence

that we have so far that that type of exposure is associated with lung

cancer death. "

" This study is compelling because it involved hundreds of thousands of

people in many cities across the United States who were followed for almost

two decades, " said study co-leader Thurston, an NYU environmental

scientist.

The JAMA study did not list data from individual cities in which the

participants lived. Researchers said the study was designed to examine the

overall health risk posed by fine particulate matter in the United States -

not compare pollution levels in various cities.

Thurston said the lung cancer risks were comparable to those faced by

nonsmokers who live with smokers and are exposed long-term to secondhand

cigarette smoke. Such risks have been estimated at 16 percent to 24 percent

higher than those faced by people living with nonsmokers, Thurston said.

In the early 1980s, when the study began, some major cities had air

pollution levels of 25 to 30 micrograms per cubic meter, which would confer

a more than 20 percent increased risk of lung cancer mortality, said C.

Arden Pope III, an environmental epidemiologist at Brigham Young University

and a co-leader of the JAMA study.

The Environmental Protection Agency set average annual limits at 15

micrograms per cubic meter in 1997, when it tightened its standards to

include fine particulate matter - pollutants measuring less than 2.5

micrometers. That is about 1/28th the width of a human hair.

That regulation followed another study by Pope linking fine particulate

pollution and lung cancer that included many of the same participants as the

JAMA study.

Pope said the new study doubles the follow-up time and does a better job of

taking other risk factors into account, to address criticism from industry

groups who challenged the earlier study and sued the EPA over the 1997

regulations. The Supreme Court last year upheld the way the EPA set those

standards.

Industry challenges to the standards are ongoing, said Jayne Brady,

spokeswoman for the Edison Electric Institute, which represents most of the

nation's major electric utilities, including operators of many coal-powered

plants.

Despite those challenges, Brady said, " We are trying to do everything we can

to reduce emissions. "

Thurston said annual fine-particulate pollutant averages have fallen

significantly since the early 1980s but as of 1999-2000 were still at or

above the EPA limit in such metropolitan areas as New York, Washington,

Chicago and Los Angeles.

He said the biggest sources of such pollution are coal-burning power plants

in the Midwest and East, and diesel trucks and buses in the West.

Thurston said the study gives new impetus to efforts in Washington to clean

up aging coal-fired power plants.

The EPA said the agency will consider the research as part of its continuing

review of air quality standards for particulate matter.

©MMII The Associated Press. .