h.3r r in 30 years from natural background exposure and they recommen lOr as the top figure for average exposure of the population as a whole hefore age 30. As to the hazard from strontium?9 the report states "if the concentration in human bones showed signs of rising greatly beyond one-hundredth of that corresponding to the maximum permissible occupational level" they would feel that immediate consideration were required. This figure is 10 times the highest they report in man today, The National Academy of Sciences report states "It Appears, then, that strontium?0 is not a current threat, but if there were any substantial increase in the rate of contamination of the atmos~ phere, it could become one.” The conclusions are to all intents and purposes identical to those of the National Academy of Sciences report. 1, Adequate justification should be required for the employment of any source of ionizing radiatior. on however small a scale. This is not explicitly stated in the National Academy of Sciemes report but is inherent in it. 2. Dose levels to the individual -- 0.3r per week -- 200 r ina lifetime for occupational exposw’es and no more than 50r the first thirty years of life. 3. lh. No more than twice natural gackground from man-made sources for the population as a whole. NAS The present and foreseeable hazacds from external radiation due to fallout at present rate of testing is insignificant. As to internal hazards from strontium’) at its present level no detect- able increase in the incidence of ill~effects is to be expected. ®Nevertheless, recognizing all ‘ae inadequacy of our present knowledge, we cannot ignore the possibility, that if the rate of firing increases and particularly if greater numbers of thermo nuclear weapons are used, we ccild within the lifetime of some now living, be approaching leve-.s at which i11 effects might be produced in a small nuaber of the population.” is a rather roundabout way of siying, "let's be careful,” Se This a, All sources of radiation stould be under close inspection. A personal record not only of coses of radiation received during occupation but also of exposur:s from all other sources such as medical diagnostic radiologys.ould be kept for all persons _ whose occupation exposes them .o additional sources of radiation. The National Academy of Sciem:s report would seem to include the whole population in its sinilar recommendations. ~hCOLLECTIONS. RrpRawiceD FRO TE THE OF ThE ie OS OF OF SCIENCES NATIONAL ACAMEMY