these tissues. Th:3 energy produces the molecule of the cells; chemical changes in for example, change could be a mutation in a cene. such a chemical The radiation dose is actually a measure of the energy transferred to or absorbed by the tissue. rad The basic unit of dose is the (one rad represents the absorption of 100 ergs of energy per gram of material). In addition to X-rays, radionuclides emit gamma rays (high energy X-rays), beta particles particles (helium nuclei). (electrons), and alpha In radiobiological experiments, it was determined that, while these various types of radiation produced the same bioloaical effects, such as cancer, magnitude of the erfect was not the same per rad. example, it was found that 100 the For rad of alpha radiation would produce roughly 10 times as many cancers as 100 rad of X-rays. Moreover, it was found that because of the special vay in which Pu-239 deposits in the bone, its alpha particles were 5 times more effective in producing bone cancer than the alpha particles from radium’, To account for these differences in the magnitude of the observed effects at the same absorbed dose in rad, the maximum permissible dose limits are given in rem rather than rad. The MPLD is given in rem in Tables I and II. 17/ ICRP Publication 11, the Tissues eT SaPrater Fy EEE tS, <d.08 ps ? Op, te yr. : a Mengage a oo be ce . rs ba in Bone," The "A Review of the Radiosensitivity of Pergamon Press, New York, N. Y., 1967, p. 21. ael LE a ep ee ae . weowee po -. TPAee Se Tee OEE UW eee Ser a ’ met ae, ge See Oa ag ./ Bere at! saver . yo ob a +. uae Se ete oh ' te , woe oa cette ri 7 oe . ou ‘ Pv bee @ var . . ‘ag , seo ot stp a : ’ Date Y } te gr * . ws wea eI aeB, go a ‘ae aH, . 4 apd * . Sg . ee PLOW Taeua | , my a. ay Ant Dog. sat ee ae ge be Sige he ot, + o ad . “fog . , + . _* . ;