Cytogenetic Instabilities in Atomic Bomb-Related Acute Myelocytic Leukemia Cells and in Hematopoietic Cells from Healthy Atomic Bomb Survivors

On August 6 and 9, 1945, nearly 65 years ago, atomic bombs (ABs) were dropped on two Japanese cities, Hiroshima and Nagasaki. The explosive powers of these two bombs are said to be equal about 12.5 kilotons of TNT for Hiroshima bomb and 22 kilotons for Nagasaki bomb. The dissipation of energy is believed to have been in the ratios consisting of 50% of bomb blast, 35% of thermal rays and 15% of radiation. Heat and bomb blast caused death in AB survivors within two weeks after bombing. On the other hand cause of death after two weeks were closely related to radiation. The initial radiation caused by the Hiroshima bomb composed mostly gamma rays including about 10 % of neutrons, on the while Nagasaki bomb emitted only gamma rays, In the both cities, a 50% death rate was estimated for those who were exposed at 1.2 km on the hypocenter. LD50 value in human was estimated as around 4 Gy from Hiroshima AB victims. Bone marrow depletion by radiation was the most critical damage leading to death. There victims who died early had extensive bone marrow damage, manifested by leukopenia and thrombocytopenia. Epilation began one to four weeks post-exposure.