reacts with lung tissue, causing,
inflammation,
and a decrease in
lung function.
Particulates -- or particles -- are tiny clumps of various substances that can get deep into the lungs and cause a variety 
of problems. According to Joel Schwartz, a former EPA official who's now at the Harvard School of Public Health, particulates have been associated with reductions in lung function and increases in respiratory symptoms and illness, as well as higher rates of school absence, emergency room visits and hospitalization.
Ozone, a molecule containing three atoms of oxygen, is a principal constituent of smog. Ozone reacts with lung tissue to cause pain while breathing, inflammation and a decrease in the lung's ability to transfer oxygen into the blood.
Both pollutants are most harmful to the young, the elderly, and the chronically ill. Here are the American Lung Association's views on the health effects of six categories of air pollutants.
Although some scientists question the scientific underpinnings of the EPA proposal, one thing is clear: They will cost money if enacted -- the EPA estimates that the necessary controls will cost $6.6 to $8.5 billion per year for at least a decade. Almost any industry that burns fossil fuels, including electric utilities, mining, oil, chemical and automotive industries, could be affected -- as could anybody who buys their products.
are tiny clumps
of soot, dirt,
and various
that have been linked to a wide variety of health
The proposal would roughly triple the number of counties that are considered to be "out of compliance" with the Clean Air Act, and that would compel more states to write plans to improve their air. Although that would cost money and increase the paperwork for some people, it also would help the elderly, asthmatics, and the young, who suffer the most from particulate and ozone pollution.
But tighter regulation could also help healthy people who are chronically exposed to air pollution, says C. Arden Pope III, an air-pollution expert at Brigham Young University. In two large studies, he says, "it was mostly healthy people who were enrolled, and high levels of particles seemed to increase the risk of obstructive pulmonary disease [like emphysema] and heart disease."
In a sign of the gathering storm over EPA's proposal, Sen. John Chafee, a Rhode Island Republican with a strong environmental record, told The New York Times on Dec. 6 that he questioned whether the benefits would be great enough to justify the costs of compliance.
The American Lung Association disagrees, noting that the Clean Air Act does not require a cost-benefit analysis, and that the benefits (mainly reductions in health expenses and absenteeism) would greatly exceed the costs in any event. "The EPA proposal was a huge step in the right direction," says Paul Billings, the association's assistant director for government relations. While the EPA "talks about a many-year phase-in of the program, we'd like to see states take action faster than that."
After 60 days of public comments, the EPA will issue final rules, which could be subject to congressional veto.
Since journalism is not encumbered by red tape, let's take some action now -- by looking at the science behind the EPA proposals. We'll start with particles, which have caused most of the
scientific controversy.
