10: Charleston, South Carolina
This historic Southern city is one of the cleanest in the country when it comes to ozone. Population: 697,439; number of children with asthma: 13,977; number of adults with asthma: 46,862. (AP Photo/Bruce Smith)
AP Photo/Bruce Smith
9: Cape Coral-Fort Meyers-Naples, Florida
These Gulf-side Florida towns have low ozone levels, according to the American Lung Association. Population: 977,720; number of children with asthma: 16,412; number of adults with asthma: 64,330. (Getty Images News/Getty Images)
Getty Images News/Getty Images
8: Burlington-South Burlington, Vermont
The air is clear in Burlington, which ranks as one of the cleanest cities in the U.S. Population: 213,701; children with asthma: 3,416; adults with asthma: 19,097. (AP Photo/Alden Pellett)
AP Photo/Alden Pellett
7: Brunswick, Georgia
Located on the coast, Georgia's town of Brunswick remains one of the cleanest. Population: 113,448; number of children with asthma: 2,879; number of adults with asthma: 7,159.(AP Photo/The Brunswick News, James Nix)
AP Photo/The Brunswick News, James Nix
6: Brownsville-Harlingen-Raymondville, Texas
Located just above the U.S./Mexico border is Brownsville, one of the cleanest cities in the U.S. Population: 437,615; number of children with asthma: 10,916; number of adults with asthma: 20,277. (AP Photo/Brad Doherty)
AP Photo/Brad Doherty
5: Bismark, North Dakota
Bismark sits smack-dab in the middle of North Dakota, and it has some of the cleanest air in the country. Population: 120,060; number of children with asthma: 1,801; number of adults with asthma: 6,981. (AP Photo/James MacPherson)
AP Photo/James MacPherson
4: Bend-Redmond-Prineville, Oregon
The air is clean and so is the powder in Bend, Oregon. Population: 183,006; number of children with asthma: 2,965; number of adults with asthma: 15,061. (AP Photo/Mt. Bachelor, Inc.)
AP Photo/Mt. Bachelor, Inc.
3: Bellingham, Washington
North of Seattle and just south of Vancouver is Bellingham, one of the cleanest cities in the U.S. Population: 205,262; number of children with asthma: 2,780; number of adults with asthma: 15,850. (AP Photo/Courtesy Whatcom Land Trust)
AP Photo/Courtesy Whatcom Land Trust
2: Bangor, Maine
This Maine city is both scenic and clean when it comes to ozone. Population: 153,746; number of children with asthma: 2,826; number of adults with asthma: 13,883. (AP Photo/Michael C. York)
AP Photo/Michael C. York
1: Anchorage, Alaska
Anchorage ranks high for its low ozone levels and also for its low 24-hour particle pollution and its annual particle pollution. Population: 392,535; number of children with asthma: 8,881; number of adults with asthma: 26,240. (AP Photo/Dan Joling)
AP Photo/Dan Joling
