This episode's headline: RADON DANGER; On the Stump; Disarming Debate. The guests include RICH GUIMOND, Environmental Protection Agency; DR. VERNON HOUK, Assistant Surgeon General; GOV. MICHAEL DUKAKIS, Dem. Presidential Candidate; REP. EDWARD FEIGHAN, [D] Ohio; REP. BILL McCOLLUM, [R] Florida; RICHARD VIGUERIE, United Conservatives of America; ANN LEWIS, Democratic Consultant. Byline: In New York: ROBERT MacNeil; In Washington: CHARLAYNE HUNTER- GAULT