Relationship Between the Radiation Dose and Chromosome Aberrations in Atomic Bomb Survivors of Hiroshima and Nagasaki

Radiation-induced chromosome aberrations were found to persist in cultured peripheral blood lymphocytes derived from Hiroshima and Nagasaki A-bomb survivors long after their radiation exposure. Earlier observations that the frequency of cells with chromosome aberrations increased in proportion with increasing dose in both cities were confirmed. However, in every dose group, the frequency of aberrant cells was consistently higher in Hiroshima than in Nagasaki. It is suggested that a higher neutron dose in Hiroshima than in Nagasaki may be a major component contributing to the difference in dose response between the two cities. Among the types of chromosome aberrations so far identified, reciprocal translocations were observed to predominate, and they played an important role in determining the dose-aberration relationship.