The Clean Air Forum was standing room only.

For two years Albert A. Presto measured air pollution at 70 sites throughout the county. An assistant professor at Carnegie Mellon University’s Center for Atmospheric Particle Studies, Presto specifically looked at levels of particulate matter otherwise known as PM2.5. Taking annual averages, the data was layered on top of a Google Earth image to illustrate varying concentrations.

PM2.5 was mapped while ozone was measured but not mapped. At a forum last night, Presto told the crowd that while ozone is bad, it’s secondary and less variable while greater understanding of PM is crucial.

“The end health effect of PM is that you die,” he said.

Dr. Deborah Gentile, Director of Research of the Division of Allergy, Asthma and Immunology for West Penn Allegheny Health System, discussed the link between air pollution and asthma.

“It is basically an epidemic in the region,” she said. “It’s not 100 percent cause and effect, but there is an association.”

Gentile said that in some communities the prevalence of asthma, almost 3o percent, is more than double that of the national rate. She added that minorities and those of lower socioeconomic standing are disproportionately affected.

Presto and Gentile presented to a standing-room-only crowd in the basement of Shadyside’s First Unitarian Church last evening. Presto pulled up a map of the United States that highlighted in blue the counties not meeting the standard for PM2.5 levels. The Pittsburgh region is a stark cluster in a mostly clear map.

“All of the significant epidemiological relationships are between PM and mortality,” said Presto. “When the EPA calculates health benefits from decreasing air pollution, 95 percent of that is PM.”

A map of black carbon pollution, a component of PM2.5, shows deep red hues in low-lying areas in Pittsburgh such as the river valleys, along the highways and near industrial operations. With pollution, it’s important to differentiate between what can be controlled and what can’t, said Presto, citing exhaust that wafts to Pittsburgh from other places.

“The next step is to start looking at sources, not just pollutant concentrations because you don’t regulate pollution, you regulate sources.”

PennEnvironment, the citizen-based advocacy group that organized the forum, voiced concerns about specific threats to air quality such as the Shenango Coke Works and the Clairton Coke Works.

Ted Popovich of Allegheny County Clean Air Now and Stephen Riccardi of PennEnvironment also spoke at the forum, urging attendees to attend other meetings and make calls to elected officials to demonstrate the community’s desire for improved air quality.

Forum attendees said their goal is to make policy makers and the Allegheny Health Department pay attention.

“I don’t think the health department is actually taking air quality complaints seriously,” said Edgewood resident Christopher Harper. “By getting more people involved, hopefully that will get back to the health department.”

Presto said his maps will be available to the public soon.

Margaret J. Krauss is a writer, radio producer, and researcher. If not biking Pittsburgh's streets or swimming its rivers, she is likely geeking out about a really good story.