C . -2- ( described for application of criteria to limit whole body dose for individuals to 0.5 rem per year and to limit exposure of a siutable sample of the population to 0.17 rem per year is likely to assure that the gonadal exposure guide will not be exceeded. Environmental radiation monitoring is a necessary part of complying with the RPG guidance. The intensity and frequency of measurements is to be determined by the need to be able to detect sharply rising trends and to provide prompt and reliable information on the effectiveness of control actions. Radioactive source control actions and monitoring efforts are to increase as predicted exposures move upward through a range of values and approach the numerical value of the RPG. A sharply rising trend approaching the RPG would suggest strong and prompt action. The magnitude of the actionshould be related to the degree of likelihood that the RPG would be exceeded. The child, infant, and unborn infant are identified as being more sensitive to radiation than the adult. Exposures to be compared with . the guidance are to be derived for the most sensitive members in the population. The guide for the individual applies when individual exposures are known; otherwise, the guide for a suitable sample (one- third the guide for the individual) is to be used. This operational technique may be modified to meet special situations. he pnd dap we hi Zl The FRC primary numerical guides, expressed in Fem, ,are provided in two reports, FRC Nos. 1 and 2, summarized in Table I. Secondary numerical guides developed by FRC are expressed in terms of daily intake of specific radionuclides corresponding to the annual RPG's. Considera- tion is given to all radionuclides through all pathways to derive 4 are