Bad air days

When ground-level ozone mixes with air pollution, smog can blanket cities, reducing visibility by 70 percent in some regions.

Report on cities' pollution says Americans aren't breathing easily

LOS ANGELES (CNN) -- Los Angeles has a reputation for smog. The city and its dirty air almost go hand in hand. But the American Lung Association says the breathing in Charlotte, N.C., isn't healthy either.

In fact, a new report from the lung association says more than 132 million Americans throughout the country are living in cities with dangerously high smog levels that could pose health problems.

The study lists the Los Angeles metro area as having the worst ozone, which results from the sun heating hydrocarbons and nitrogen oxides in vehicle and industrial emissions.

But even much smaller California communities -- such as Visalia, Tulare and Porterville in the central part of the state -- received an "F" in a national grading system that the association used to compile its "State of the Air 2000" report.

"Hospital emergency room visits for respiratory problems, like asthma, go up almost in lockstep with the amount the ozone levels have gone up," says Rich Varenchik of the California Air Resources Board.

To determine best and worst cities, the American Lung Association counted the number of days that a county or metro area had unhealthy smog levels in 1996, 1997 and 1998. Those are the most recent years for which Environmental Protection Agency figures are available. Communities that experienced 10 or more days of unhealthy air during that time period received an "F."

California not alone in bad air

Six of the top 10 places with the worst ozone record were in California. But as the report points out, communities receiving an "F" are scattered throughout the country. Nationwide, 120 localities received that grade.

"In the Rocky Mountain and Southwest areas, where Easterners once flocked because of its then-pristine air, Denver, Salt Lake City, Phoenix and Houston are clouded with smog," the report says.

"The same is true of Boston in New England; New York, Philadelphia, Baltimore and Washington in the Mid-Atlantic; Charlotte, Atlanta and Birmingham in the South; Pittsburgh, St. Louis and Chicago in the Midwest; and a dozen or so areas of California, including Los Angeles and San Francisco. Only in the Pacific Northwest is the situation less grim," it says.

At risk: Millions of all ages

Bellingham, Wash., headed the list of metro areas graded "A" for having the best record on ozone pollution. Among the others in that category, only Honolulu has a metro population greater than half a million.

Of the more than 132 million Americans living in areas whose air quality failed, the lung association says:

"Ozone smog represents the single most challenging pollution problem the country is facing," says Dave Cohen of the EPA.

The EPA enacted stricter ozone standards in 1997, but business groups ranging from trucking companies to electric utilities sued, which blocked enforcement.

The U.S. Supreme Court said Monday it would hear arguments on the clean air standards and issue a decision during its term beginning in October.

Correspondent Greg LaMotte contributed to this report