The "Most Livable City in America" is also the dirtiest - at least in terms of short term particle pollution according to the 2008 State of the Air report by the American Lung Association. This is the first time a city outside of California has topped the list. Following Pittsburgh on the list of metropolitan areas most polluted by short-term airborne particles are Los Angeles/Long Beach/Riverside, Fresno/Madera and Bakersfield, all in California, along with Birmingham, Alabama.

Most people reading the report probably aren't surprised in the least - except, perhaps, for those of us actually living in Pittsburgh. Although, many people still think of Pittsburgh as the dirty, smoky city it was 50 years ago, steel is no longer king here and the city has cleaned up quite nicely. Reports like this one sure don't do much to help us clean up the outdated image people have of the Steel City!

Guillermo Cole, a spokesman for the Allegheny County Health Department, said that Pittsburgh's poor ranking is based primarily on high soot readings in the Monongahela River Valley caused by emissions from U.S. Steel's Clairton Coke Works, according to an article in today's Pittsburgh Post-Gazette.

"The fact of the matter is that the ranking only applies accurately to the Liberty-Clairton area, and Pittsburgh, the rest of the county and the surrounding counties have much better air," Mr. Cole said. "Liberty-Clairton is a unique situation. We have a large source, the coke works, sitting in a river valley, so it's a real challenge. There's no other area of the U.S. like that."

The U.S. Environmental Protection Agency recognizes that the high readings at two monitors located in Liberty Borough and Clairton are not representative of the air quality in the rest of the region. Thats why, in 2005, it designated five municipalities in the Mon Valley as a separate non-attainment area for particulate matter pollution. This ensures that the monitors there do not affect the ability of the rest of the region to meet federal standards for air quality. The American Lung Association, however, still includes these two monitors in its ranking of the Pittsburgh region, resulting this year in its No. 1 spot for worst short-term particle pollution.

Kevin Stewart, director of environmental health for the American Lung Association of Pennsylvania, said he understands the frustration with Pittsburgh's No. 1 ranking, but even if the two Liberty-Clairton area monitors are removed from the calculations, the remainder of the five-county Pittsburgh metropolitan area would still rank 16th worst out of the 222 metropolitan areas covered in the report. It's definitely not as bad as No. 1, but there is still plenty of room for improvement.

Plans are in place for a $1 billion cleanup by U.S. Steel Corp. at its Clairton Works coke-producing operations, the country's largest coking operation, with complete compliance expected by 2015. U.S. Steel has also reached a deal with the Allegheny County Health Department to correct air pollution violations at the Edgar Thompson Works in Braddock.

So where is the rest of the pollution coming from? Air sampling research at Carnegie Mellon University has shown that power plants and industries located upwind of Pittsburgh are major sources (up to 80 percent) of the particles in Southwestern Pennsylvania. Pittsburgh is located in a sheltered river valley, which some hypothesize leads to the settling of pollution carried from other areas. So is its high pollution rating really Pittsburgh's problem? I say yes. We can't do much about pollution coming in from outside our area, but there is always room for improvement here at home. Groups like GASP (Group Against Smog and Pollution) offer solutions, as does much of the green technology going on in our region. Instead of complaining about the undeserved No. 1 ranking, all of us here in Southwestern PA need to do our part to reduce air pollution here at home. The actions we're all asked to take on Air Quality Action Days are rules we should live by every day - when practical and possible.