Research Links Air Pollution to Lung Cancer

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Research Links Air Pollution to Lung Cancer

Health: People in the smoggiest U.S. cities are said to face a malignancy

risk 20% greater than those living in cleaner areas.

By GARY POLAKOVIC

TIMES STAFF WRITER

March 6 2002

In a new study of air pollution, scientists Tuesday reported a link between

hazy skies over U.S. cities and life-threatening illnesses, including lung

cancer.

A link to cancer had long been suspected but not established. Now a team of

researchers from Canada, New York and Utah has found that people living in

hazy cities across the nation are more likely to die of lung cancer, heart

attacks and respiratory failure than people in communities with cleaner air.

They found that for every 10 micrograms of tiny particles swirling in the

air, the risk of dying of lung cancer increased by 8%. Someone living in

heavily polluted Bakersfield or Rubidoux, Calif., faces a risk 20% greater

than someone living in Pueblo, Colo. While the threat pales in comparison

with cigarette smoking or exposure to toxic chemicals in factories, it is

comparable to the hazard posed by secondhand smoke, according to the

American Lung Assn.

" This study provides the most definitive epidemiological evidence to date

that long-term exposure to air pollution is associated with lung cancer

deaths, " said Thurston, a co-author of the study and associate

professor of environmental medicine at New York University.

The report is being published today in the Journal of the American Medical

Assn. It followed more subjects, about 500,000 adults, for 16 years, longer

than any other study of its kind and included 156 cities, ranging from

Buffalo to Los Angeles and from Pittsburgh to Huntington, Ala.

Researchers from Brigham Young University, the University of Ottawa, NYU and

the American Cancer Society participated in the study. It was funded by

grants from the National Institutes of Health and other government agencies.

The study comes during a time of intense political debate over the future of

air pollution controls, and clean-air advocates seized upon it to challenge

the Bush administration's recent attempts to alter the nation's clean-air

regulations.

Two weeks ago, the White House unveiled a new anti-smog strategy for

industrial and power plant emissions, but environmentalists and many air

quality officials rejected it as an attempt to roll back pollution controls.

Last week, the EPA's chief of air pollution enforcement resigned in protest

over Bush administration policies he said are weakening clean-air rules,

particularly those that require power plants to install the most modern

emission control equipment. Emissions from power plants are a major source

of haze in national parks and in the eastern half of the country.

" It makes no sense to weaken the Clean Air Act in light of this important

new evidence. It raises urgency to moving forward to reduce fine particles, "

said A. Blakeman Early, a consultant to the American Lung Assn.

The new study will likely lend support to maintaining the nation's standard

for regulating fine-particle pollution.

The standard, which was approved in 1997 and affirmed by the U.S. Supreme

Court, targets particles that are 2.5 microns or smaller. Health experts say

the latest study reinforces the need to retain that air pollution standard

and hasten air pollution cleanup.

" This study is good news because it shows our efforts in the past and

current efforts to improve our air quality are not in vain but will in fact

result in significant improvements in public health, " said C. Arden Pope,

the lead author of the study and an environmental epidemiologist at BYU.

For years, air pollution cleanup has focused on ways to reduce ozone, a gas

that reduces respiratory function. Yet, more and more studies implicate

microscopic particles that form haze as a serious health risk. While ozone

levels are generally in decline nationwide, and dramatically so in Southern

California, progress against particle pollution is more modest.

Haze comes from dust and soot. Significant sources include farm equipment,

dust blowing off unpaved roads, diesel trucks and buses and portable

generators.

The most dangerous particles are the smallest specks, which can float in the

air for weeks, circumnavigate the globe and bypass the body's defenses to

lodge deep in the lungs. Those particles come primarily from fossil fuel

combustion, and some are formed when emissions from power plants, factories

and vehicles react with sunlight to form microscopic bits.

California has some of the nation's highest particle pollution levels, due

in part to its geography. Valleys surrounded by mountains tend to trap the

haze created by cars and factories.

" We recognize it [particle pollution] as a major problem, " said Shankar

Prasad, health advisor to the California Air Resources Board.

Yet even in the latest study, scientists remain puzzled over which component

of particle pollution is most injurious to health. Some say it may be a

specific component while others say the sheer volume of particles in the air

is dangerous.

" It may just be the insult of particles and the reaction they instigate in

the lung, " said Morton Lippmann, director of the Particulate Matter Health

Research Center at NYU.