A. Acute Effects

Review of Thirty Years Study of Hiroshima and Nagasaki Atomic Bomb Survivors II. BIOLOGICAL EFFECTS

Abstract

An outline of the acute effects of the Hiroshima and Nagasaki atomic bombs are summarized, based on documentary records. Acute injuries caused by the atomic bombs have been classified as thermal, mechanical, and radiation injuries. Combinations of these were most common. Many died from the immediate effects of blast and burns, but individuals often succumbed to trauma or burns before the radiation syndrome developed. Many more would have died from irradiation, had they been saved from the effects of trauma or burns. Nearly all who died within 10 weeks had signs suggestive of radiation injuries. Remarkable variation in sensitivity of body tissues to ionizing radiation was apparent. Radiation-induced bone marrow depletion was the most critical damage leading to death. In these instances, leukopenia and thrombocytopenia, and subsequent infections and hemorrhagic tendencies were the main causes of death. The clinical symptoms and signs of radiation injuries; the RBE of the atomic bomb neutrons for acute effects; and the effects of irradiation on spermatogenesis are also discussed.