Nine of the top 50 power plants with the highest sulfur dioxide emissions in the nation are in Pennsylvania, including five of the top 10, according to a new report by the Environmental Integrity Project.

Those five top 10 sulfur dioxide emitters are Allegheny Energy's Hatfield's Ferry plant in Greene County and Armstrong plant in Kittanning, Armstrong County; and Reliant Energy's power plants at Shawville, Clearfield County, Portland, Northampton County, and Keystone, in Shelocta, Armstrong County. Four of the five are in the western half of the state.

Titled "Dirty Kilowatts," the report released today in Washington, D.C., also measures emissions of mercury, nitrogen oxides and carbon dioxide by the nation's 359 largest power plants.

The report finds that the 50 power plants spewing the most pollution are older facilities that produce as little as 14 percent of the nation's electricity.

Eric Schaeffer, former head of civil enforcement for the U.S. Environmental Protection Agency and EIP founder and director, said most of the unhealthy emissions are preventable.

"A huge share of these emissions comes from a handful of unnecessarily dirty power plants that have not yet installed modern pollution controls or which operate inefficiently," Schaeffer said.

Sufur dioxide and nitrogen oxide emissions contribute to the formation of fine airborne particles and soot that triggers asthma attacks and causes lung and heart disease linked to more than 20,000 premature deaths a year. Carbon dioxide gases contribute to the gradual warming of the planet. Mercury is a deadly neurotoxin, especially dangerous to developing fetuses.

More details in tomorrow's Pittsburgh Post-Gazette.