Continued X-ray Microanalysis of Radioactive Fall-out Particles during the Year 1962

Abstract

SINCE the beginning of atom bomb tests, the physical and chemical properties as well as the biological effects of radioactive fall-out particles have been the subject of numerous investigations^1–8. Discussions on the mechanism of formation of these particles and on the question of their effects on the human organism after inhalation or ingestion^1,2,4, which are highly dependent on their solubility, require a knowledge of their composition^1,4,9. Comparison of particle diameters, obtained by electron microscopy, with the content of radioactive nuclides, determined by radiochemical methods and γ-spectrometry, shows that the particles contain more inactive material than is produced by the decay of the radioactive fission products and the induced radioactive elements^2,9. In the case of atmospheric explosions, this additional inactive component comes from unfissionable materials used in building the atomic device, and in the case of near-surface explosions also materials from the ground can be involved¹.