7, The state of knowledge in the field of genetics 8, Keep all exposures to the germ cells as low as has been outrun by our knowledge in the field of physics. possible for radiation expesure is generally detrimental to living celis, In essence, this Committee formalized the current thinking on the subject, It did not come up with any new or Startling conclusions or recemmendaticns, The Committee on This Committee was composed of scientists well versed in radiation pathology and chaired by Dr. Shields Warren, Director of the Cancer Research Institute of the New England Deaconess Hospital, Boston, Massazhusetts, and was for five years =~ 1948 to 1952 -- Director of the Division of Bislogy and Medieine of the Atomic Energy Commissdcn, This group and subcommittes;on blood, lung, delayed effects, and toxicity of ingested radioactive materials reviewed the present state of knowledge and found that our knowledge of immediate effects was much greater than for delayed effects, | They observed a five year lessened life span for American radioiogists, estimated to have received from a few roentgens to 100Gr of exposure as compared with physisians not using radiation ~and agreed that until we had more precise knowledge of the’ cumu- lative effects of repeated small exposure of the whole body to radiation the rule of thumb recommended by the Genetics Committee could equally well apply to medical effects, That is, no one should receive more than 50r total accumulated dose to the repro~ ductive cells by age 30 = and no more than 50r for each decade thereafter, This, they felt, would assure that any life expectancy curtailment would be exceedingly minor, and the likelihood of induced leukemia minimal, They noted that as far as effects on the blood-forming organs, the intestinal tract, etc., are con-~ cerned, none of these effects have been detected among those who have adhered to present permissible dose levels, . NAS As for the hazards from ingestion and radicactive materials, they confirmed the validity of existing National Com mittee for Radiation Protection and International Commission for Radiation Protection recommendations and as for the most important of the fission products in fallout, namely Strontium-90, they stated "there seems to be no reason to hesitate to allow a universal’ human strontium burden of 1/10 cf the permissible yielding 20 rep in a lifetime,,,,, Visible changes in the skeleton have been reported a5 = oss