RP 2-75

Research plan for RERF Adult Health Study, Hiroshima and Nagasaki


The Adult Health Study is based on a sample of 20,000 volunteers in Hiroshima and Nagasaki, composed of selected exposed individuals matched by age and sex with nonexposed persons. The purpose of this study is to compare the physical condition, illness episodes, and deaths when they occur, of the exposed with the controls. The Adult Health Study is an attempt to measure differences in the life experience between the exposed and the nonexposed as shown by fairly comprehensive medical records. The statistically matched samples for such a comparison are required because to date the sequelae of exposure to radiation beyond the acute stage are manifested only in variations in rates of diseases which also occur in nonexposed without any physiological differences determinable by clinical or diagnostic procedures.

In order that the Adult Health Study might be carried out successfully, the understanding and cooperation of many groups in addition to the all-important volunteers are required. The Japanese Ministry of Health and Welfare, particularly the section on the Atomic Bomb Survivors Medical Treatment Law, has a major interest and in December 1958 ABCC informally opened conversations to offer the study to the Ministry for collaborative use. The prefectural and city governments of Hiroshima and Nagasaki are intimately concerned. The medical societies, government and private hospitals, the medical schools, and other private and governmental agencies interested in medical care and research are involved in various ways.

The signed agreement between the Atomic Bomb Casualty Commission (ABCC) and Japanese National Institute of Health (JNIH), Ministry of Health and Welfare, formalizes the joint long-term conduct of the Adult Health Study in Hiroshima and Nagasaki.


The study is planned as an intensive search for the late effects of single, wholebody irradiation from the Hiroshima and Nagasaki bombs. Although dosimetry information is by no means definitive at this time, preliminary information suggests that the effects of radiation doses up to 600 rad can be effectively studied in the surviving samples.

The potential radiation effects may be classified as follows:

Alterations in the incidence of disease;

Alterations in the natural history of disease, with or without alteration in incidence;

Development of physiological or biochemical changes, short of actual disease;

Nonspecific changes in vigor or acceleration of aging;

Occurrence of new diseases,to radiation.

It is a specific objective of this investigation to illuminate the pathogenesis of diseases which may be found to be related to radiation.

The research plan should also enable the investigator to make adequately strong negative statements when competent examination of the data has shown no evidence of a particular effect.

Three levels of observation are defined:

A basic routine medical examination including history, physical examination and laboratory tests to be repeated periodically.

Extension of the routine examination to include more detailed study of particular systems or diseases;

Supplementary observations suggested by particular ideas about possible effects.

It is believed that by operating at these three levels the search will be deeper in the long run and the special importance of ideas will not be neglected.

Sampling Plan

In accordance with the general framework of the Unified Study Program, the sample for the present study has been drawn from the Master Sample defined for the joint JNIH-ABCC Life Span Study. Further, it is a probability sample in that eligible individuals of the same sampling category all have the same chance of inclusion in the sample. It is, of course, to be a fixed subsample of the Master Sample, not subject to future change.

Collection of Data

A standard medical history will be taken, physical examination performed, and laboratory studies made, all according to a fixed pattern. The design and specific content of the record forms will naturally change in the course of time as experience is gained on the basis of accumulated results.