We like to believe our home is our castle, but how safe is the air inside our houses? Although we spend 65 percent of time at home, we may be exposed there to unseen dangers. Mold, mildew and other pollutants can build up in crawl spaces or heating ducts and endanger health. How can we prevent indoor air pollution? Guests: Michael Osborne, Chief of the Indoor Environment Management Branch in the Division of Air Pollution, Prevention and Control at the U.S. EPA. Mary Jane Selgrade, PhD, Chief of the Immunotoxicology Branch in the Experimental Toxicology Division of the National Health and Environmental Effects Laboratory at the U.S. EPA. Arnie Katz, Director Healthy Buildings Resource Center at Advanced Energy, Raleigh, NC.