. - 12 - these tissues. This energy produces chemical changes in the molecul2 of the cells; for example, such a chemical chance coulc be a mutation in a gene. The radiation dose is actually a measure of the energy transferred to or adsorbed by the tissue. rad The basic unit of dose is the (one rac represents the absorption of 100 ergs of energy per cran of material). . In acSition to X-rays, radionuclides emit gamma rays . X-ravs), beta particles particles (helium nuclei). (electrons), and elpha In radiobiological experiments, iti was determined that, while these various types of radiation produced <=ne same biological effects, such as cancer, masnituce cf the effect was not the same per rad.. example, it was found that 100 rad of alpha the For radiation vould prosuce rourtnly 10 times as many cancers as 100 rad of Moreover, it was found that because of the srecial ich Pu-239 deposits in the bone, its alpha varticles were 3 tines more effective in producing bone cancer tran the Tha “MELD . 7 iron radium . is civen ation tne," . To account for these differences in rem in Tables I and II. Tha ll, "A Peview af the Radiasansitivi Perqamon Press, Mev York, N. Y. 19 rr - . oe alona particles : saree ip me