Five years after Three Mile Island awakened Americans to the dread of radioactive release, a new and potentially more consequential radioactive threat was discovered in a Pennsylvania home. Touted as the second major cause of lung cancer, the radon problem was prominent as a leading environmental risk. However, widespread acceptance of this risk has never materialized. In this vibrant account, Edelstein and Makofske unveil the complex mix of social and scientific factors that have led to public and official misunderstanding of the geologic radon issue. The lessons of radon have great relevance in a contaminated world where people are increasingly surrounded by invisible environmental hazards, where uncertainty and controversy shroud a clear understanding of the threat, and where one can choose apathetic acceptance or attempt to discern how to actively protect oneself and one's family.