be exceeded without careful consideration of the reasons for doing so,© and that every effort should be made to encourage the maintenance of radiation doses as far below these guides as practicable. To comply with these standards, First, certain conditions must be met. the basic FRC recommendation is it “...that the yearly radiation exposure to the whole body of individuals in the general population...shoulid not The FRC recognized, however, that exposure of exceed 0.5 rem."/ individuals may be difficult to monitor under some circumstances; thus they suggested that the limit to individuals may be met by use Of average limits to the popualtion. the Second, therefore, the FRC indicated that: ''Under certain conditions, such as widespread radioactive contamination of the environment, the only data available may be related to average contamination or exposure levels. these circumstances, Under it 1s necessary to make assumptions concerning the relationship between average and maximum doses. Radiation Council suggests The Federal the use of the arbitrary assumption that the majority of individuals do not vary from the average by a factor greater than three. Thus, we recommend the use of 0.17 rem for yearly whole-body exposure of average population groups... this guide be applied with reason and judgment. It is critical that Especiaily, it is noted that the use of the average figure, as a substitute for evidence concerning the dose to individuals, is permissible only when 6The Federal Radiation Council, in Report No. 1 (see footnote 4, pp. 26-27), Stated that the guidance should not be exceeded unless "...a careful study indicates risk." that 7See Note 4, p. 26. the probable benefits will outweigh the potential 5 1g 4 ? : it 4 _