Summary: We know that burning coal produces greenhouse gases that cause global warming. But burning coal is a big source of other types of air pollution that can cause disease and even death. Around the country, dozens of coal-burning power plants are racing to comply with new EPA rules to keep mercury out of the air. In Michigan, Consumers Energy and DTE Energy are both spending roughly $2 billion dollars to comply with new air rules. Reid Frazier got an inside look at a plant in Pennsylvania that's making big changes of its own.
