"The bottom line is that Cincinnati is a polluted city, and children with asthma, senior citizens and others with breathing problems are suffering the most," said Emily Figdor, a clean-air advocate for the group that released the study.

The U.S. Environmental Protection Agency released data this week that showed soot-forming sulfur dioxide pollution from power plants in Ohio increased by 4 percent from 2002 to 2003, the most recent year for which data are available.

Tiny particles of soot can lodge deep in the lungs, causing respiratory and cardiovascular problems.

The report issued by the Ohio Public Interest Research Group examines soot pollution for the first time in addition to smog pollution. In Cincinnati, smog triggers 57,000 asthma attacks each year, the group said.

Glen Brand, the Sierra Club's Midwest regional representative, said this time of year in Cincinnati is "a time of wheezing. Asthma is an epidemic here."

Cincinnati smog surpassed that of larger cities, such as Chicago, Atlanta and Washington.

Ohio ranked fifth nationwide for the worst year-round soot pollution.

Scott Segal, director of the Electric Reliability Coordinating Council, said environmental organizations are selective in referencing data.

"Environmental organizations are again clouding the truth regarding air quality," he said in a statement. "In reality, data released this week shows that air quality for the six major emissions from industrial sources has again declined."

E-mail mdowns@enquirer.com