What could possibly be interesting about mold and mildew, you ask? Itâ??s all in the content and the presentation style of the person discussing the subject. IAQ Radio is delighted to have internationally known and acclaimed expert on the subject McGregor Pearce of St. Paul, Minnesota, for a 3rd appearance on our program. Mac is an environmental health consultant specializing in indoor air quality problems. He has investigated mold in homes, commercial buildings, hospitals, clinics and skyscrapers. Mold and mildew are at the root of a number of health problems and contribute to building degradation. Mac makes mycology marvelously interesting.