Summary: On this week's The Allegheny Front, we take you to a busy Pittsburgh traffic tunnel where scientists are in search of soot. What they find is changing how we see the pollution around us. And two coal-fired power plants in southwestern Pennsylvania are slated to close. The reasons for the closures aren't as simple as they seem. Plus, a hot summer reading list for those with the climate on their minds. All this, and more. http://media.alleghenyfront.org.s3.amazonaws.com/AT072713Show.mp3
