Although such tragedies as the atomic bombings in Hiroshima and Nagasaki in 1945 should never be repeated, these unfortunate experiences have greatly enhanced our knowledge of the health effects due to ionizing radiation.
Studies on the late health effects of ionizing radiation among the atomic bomb survivors have been conducted since 1947 by the Atomic Bomb Casualty Commission (ABCC) and its successor, the Radiation Effects Research Foundation (RERF) which is equally funded by the two governments of Japan and the United States.
The results thus far obtained up to the present can be classified into the following three categories:
(1) The effects for which a clear increase has been found include malignant neoplasms, cataracts, chromosomal aberrations, small head size and mental retardation among the in utero exposed.
(2) A suggestive increase has been found in the several sites of cancers and immunological abnormalities.
(3) No difference has been observed between the exposed and the non-exposed in some types of leukemia, osteosarcoma, accelerated aging, sterility and hereditary effects.