TheAmerican Lung Associationreleased its State of the Air 2011 report yesterday and there is some good news, although widespread poor air quality continues in many cities across America.

The report grades metropolitan areas across the U.S for short- and long-term particle pollution as well as ozone pollution.

Some good news: Twenty-five of the top 27 most-polluted cities for year-round particle pollution levels had cleaner air than last year’s report found.

Some mixed news: While progress continues to be made in fightingozone pollution, still almost half of all Americans live in areas with unhealthful levels of ozone.

Some bad news: Roughly half the people (50.3 percent) in the United States live in counties that have unhealthful levels of either ozone or particle pollution.

All but two of the cities with the worst year-round particle pollution improved. The two that worsened:Bakersfield, Calif., andHanford, Calif.Keep in mind the report is based on data collected through 2009, and so it does not reflect any changes in air quality last year.

The cleanest cities in the U.S.?HonoluluandSanta Fe, N.M., were the only metropolitan areas landing on all three of the cleanest-cities lists. Honolulu was the cleanest city in the U.S. for ozone air pollution, whileCheyenne, Wyo., was cleanest for year-round particle pollution andCorpus Christi/Kingsville, Texas, was cleanest for short-term particle pollution.

For a closer look at the key findings of the State of the Air 2011 report,click here.