Studies on the health effects of a-bomb radiation exposure appeared in health examinations of adult survivors by the Radiation Effects Research Foundation

The Research Foundation has conducted the health examinations in the title since 1958, based on which studies of a cohort type have been performed, and their results at present are summarized in this paper. Subjects have included a cohort of about 120000 cases in total. They have been those 4993 initial cases (the center group) exposed to estimated radiation doses of 4 -6 Gy within the distance of 2 km from the hypocenter and with acute exposure symptoms either in Hiroshima or Nagasaki, and 19961 cases (exposed ones within 2 km from the hypocenter but without the symptoms, exposed residents in the city 3 km far from the hypocenter, or ones absent in the city at explosion) matched to the above center group in the city, age and sex. Lower statures and weights are noted in some of the center group who were in growing ages at exposure. Increases of prevalence or incidence rate are suggested in malignant tumors, diseases of the thyroid and parathyroid, uterine myoma, chronic liver diseases, cataract, circulatory diseases, abnormal hemoglobin value, and psychological states. Relative risk at 1 Gy for incidence of non-cancer diseases is calculated and presented. Results are not always consistent with those of such population exposed to <6 Gy as that of Chernobyl Accident, of radiation technologist and of people accidentally exposed to environmental radiation. The Foundation is to continue the study and more profound results of radiation effects are expected to be obtainable. (T.I)