Electron spin resonance analysis of tooth enamel does not indicate exposures to large radiation doses in a large proportion of distally-exposed A-bomb survivors.

The atomic bombs in Hiroshima and Nagasaki led to two different types of radiation exposure; one was direct and brief and the other was indirect and persistent. The latter (so-called exposure to residual radiation) resulted from the presence of neutron activation products in the soil, or from fission products present in the fallout. Compared with the doses from direct exposures, estimations of ind...