Risk estimation in radiation carcinogenesis depends primarily on epidemiological data and hazard rate models. The A-bomb survivors follow-up provides information on the complexity of this process. Several hazard rate models are briefly discussed and illustrated using the A-bomb experience.

The secret of the hydrogen bomb went from being an icon of nuclear secrecy to something that could be widely reproduced on the Internet and in children's textbooks. The rise and fall of the H-bomb secret reveals both changing attitudes towards state secrecy in general and the contingent nature of secrecy, depending on an imagined threat as guidance.