"Catherine Caufield has written an important book on an important topic: the history behind the safety standards limiting the effects of high energy radiation on human beings. . . . Provides an immense amount of information in a very readable form."-W. Alan Runciman, Prometheus"From fallout and radon to radioactive smoke detectors and dental X-rays, Caufield traces the proliferation of the uses of radiation in medicine, industry and the military, and in generating energy. An intelligent, non-alarmist history."-Publishers Weekly