eee ' . GRITRRTAVE + a Reutine Radiation Exposures DISCUSSION In 1953 the following reccmmendation was made in the "Report of Com mittee to Study Nevada Proving Ground": "It is recomnended, and found to be in conformity with the present principles of determining permissible exposure limits, that for test operation personnel the total body gamma exposure be limited to 3.9 r in thirteen weeks, and that the same figure be applied to the off-site communities with the further qualification in the latter case that this is the total figure for the year. In general, this implies a single test scries in any given year." On the basis of this recomnendation and the reasoning discussed under Criteria I, the criteria for estimating the whole-body gamma effective It will be noted thst the bio- legical factor intluded under Criteria I is omitted in Criteria V. In the first case we are dealing with relatively high doses that may require einergency measures With their sttendant hazards. It is a situation where one wishes to estimate all pertinent factors in evaluating radiation doses even though they may not be mown with preciseness, before recommending an emergency action that may produce greater problems. In the case of Criteria V one is concerned with relatively lower doses during routine operations. It would be difficult to justify on the one hend the proposition that weekly doses for general populations may be integrated and taken in a single exposure without penalty and on the cther hand, that a given dose received over & period of a year may be administratively reduced because of biolog- ical repair. Therefore, the biological facter is omitted. The general effects of backscattering on measured radiation doses are fairly well established. Further, knowledge of depth (tissue )-dose curveshas advancedto a _quantitative state.* Thus.s there seems to be *Permissible Dose From Exte sources of Ionj National Bureau of Standards Handbook 59. September 24, cm CS fy, FL ayl th eninge 4 wr my OR ae2Aen sin9aE eeeeneeseaternse)So cane Ot ‘ biological dose are summarized in table V,