Reflections on the work of the Atomic Bomb Casualty Commission in Japan.

The atomic bombs dropped on Hiroshima and Nagasaki in 1945 led to the organization of the Atomic Bomb Casualty Commission (ABCC), whose history contains important lessons for epidemiologists concerned with large-scale investigations of problems requiring long-term, prospective study. The history is perhaps all the more meaningful because it is not a linear process starting from a definitive protocol and moving through well-planned stages of development to a fulfillment clearly visualized at the outset. Rather, it is an adaptive process, the record of a struggle against difficulties of many different kinds, its continuation dependent on the vision of relatively few people, on the growing social need for information about the health hazards created by a burgeoning nuclear technology, and on a belated infusion of epidemiologic concepts and methods without which the studies of somatic effects seemed doomed to failure. But it is also a bifurcated history, in that the genetic studies do not fit this general pattern. They stand apart as superbly planned and efficiently conducted and yet with little evident influence on the somatic studies which have come to dominate the program.