NEW YORK Honolulu and Santa Fe, New Mexico, are the U.S. cities with the best air quality, while Los Angeles and several others had the foulest, according to an American Lung Association report.
While the nation's most smoggy cities all improved their air quality over the last year, half the nation's residents still live with unhealthy levels of air pollution, added the report, released on Wednesday.
The "State of the Air 2011" report concluded that the U.S. Clean Air Act, the federal law aimed at limited pollution in U.S. Skies, is working.
"The progress the nation has made in cleaning up coal-fired power plants, diesel emissions and other pollution sources has drastically cut dangerous pollution from the air we breathe," said Lung Association President Charles Connor in a statement.
The most dramatic improvement has been controlling ozone, commonly known as smog, with all 25 cities most polluted by ozone having cleaner air than they did last year.
Still, 154.5 million people, just over half the U.S. population, live in areas where the air is filled with dangerous levels of smog and particle pollution, known as soot.
Cities with the foulest air were broken down into three categories.
The worst three for ozone pollution were Los Angeles, Bakersfield and Visalia, all in California. Bakersfield and fellow California city Fresno, along with Pittsburgh, Pennsylvania, had the most short-term particle pollution, while Bakersfield, Los Angeles and Phoenix had the worst year-round particle pollution.
Honolulu and Santa Fe had the best overall air, the report said.
(Reporting by Reuters Health; editing by Elaine Lies)