Monongahela Valley wind bad for lungs, CMU says

City dwellers with breathing problems should check air quality reports on summer days when the wind blows up from the Monongahela Valley, according to a report from Carnegie Mellon University.

Wind from the southeast is nearly six times as likely to carry pollution that elevates the amount of lung-clogging soot in the air around East End neighborhoods. The scientists believe this is because pollution from U.S. Steel's coke works in Clairton and Braddock funnels up the valley into Pittsburgh along breezes from the south.

"The finger is pointing at these sources for a couple of reasons," said Cliff Davidson, co-author of the analysis and professor of civil and environmental engineering at Carnegie Mellon. "One is because they are fairly close to Pittsburgh. In addition, coke works, in general, have more emissions at ground level, so they're not coming from high stacks and carrying for long distances."

U.S. Steel spokeswoman Courtney A. Boone noted there are several contributors to the soot and said the company is reviewing the information.

"Since the data was produced in 2002, the company has made good progress on our environmental performance throughout the Mon Valley Works, including Clairton," Boone said.

U.S. Steel is spending $1.2 billion to upgrade to its Clairton Coke Works and expects that to reduce soot by nearly 60 percent. The company increased pollution controls on its Edgar Thomson works.

Davidson and his colleagues, graduate student Nanjun Chu and Joseph Kadane, a professor of statistics and social science, placed a device atop a hill in Schenley Park that gave air pollution readings every 10 minutes between July 2001 and September 2002.

They discovered that on 18 percent of days when wind blew from the southeast, levels of fine soot, called PM2.5, rose above the national standard. When the wind came from any other direction, usually the west, soot levels exceeded the national standard 3.1 percent of the time.

"PM2.5 is one of the most dangerous pollutants because the particles are so small that your lungs don't filter them out. Larger particles you cough up," Kadane said.

A spokesman for the Allegheny County Health Department said air quality improved in the seven years since the report's data were collected.

The Group Against Smog and Pollution, based in Squirrel Hill, where pollution blown north from the Mon Valley falls, continues to campaign for stronger controls on pollution sources.

"You can't take a 'not in my backyard' approach to air pollution," said GASP attorney Joe Osborne. "Out of sight, out of mind doesn't necessarily mean out of lungs."