Every morning from 7am-8:30a
Los Angeles was once again at the top of the list for the worst ozone pollution in the country. The City of Angels topped the list for the 13th time in the 14 years.
Californians actually inhale the dirtiest air, with seven of the top-10 most air polluted cities on the list being in that state.
Houston, Dallas and Washington, D.C., rounded out the top 10 for dirtiest air.
Four cities were called out for having the cleanest air overall, meaning they didn't have any days at the unhealthy level for ozone. Those states were Bismarck, North Dakota, Cape Coral-Fort Myers, Florida, Palm Bay-Melbourne-Titusville, Florida and Rapid City, South Dakota.
The majority of cities that topped the list for lower ozone pollution tended to be in the western part of the country in states like Colorado, Arizona and Utah.
Here's the entire story/list from ABC. http://abcnews.go.com/blogs/health/2013/04/24/los-angeles-tops-dirty-air-list-for-13th-time-in-14-years/