RADIATION STANDARDS, INCLUDING FALLOUT 153 other organs in the body—actually, by a factor of 2—this factor is not permitted in the case of a child because the child’s thyroid does not have this radioresistance. At least. the evidence would suggest that. it does not. Mr. Ramey. This factor of 10 applies in a great deal of your radionuclides and other radioactive hazards. Where you begin to approach nearer to where you might have damage as against. a sortof danger signal used by your general population maximum permissible dose or level in your radiation guides. Dr. CHapwick. We have accounted here for two factors of 10 and then an additional factor of the orderof2. Representative Price. Are there any further questions? If not, the committee will recess until 2 o’clock this afternoon. Thefirst witness will be Dr. Wright Langham. Dr. Chadwick, the committee appreciates your fine presentation and the valuable information which you have supplied for this hearing. Dr. Caapwick. Thank you,sir. (Whereupon, at 12:20 p.m., the subcommittee recessed, to reconvene at.2 p.m., the same day.) AFTERNOON SESSION Representative Price. The committee will be in order. This is a continuation of hearings on radiation standards including fallout. The committee will finish hearing witnesses on worldwide fallout since 1959 and then hear the pane] discussion on predictions. The first witness this afternoon will be Dr. Wright H. Langham of the Los Alamos Scientific Laboratory. Dr. Langham. STATEMENT OF WRIGHT H. LANGHAM,’ LOS ALAMOS SCIENTIFIC LABORATORY Dr. Lancuam. Mr. Chairman, members of the subcommittee, I have submitted two documents to Mr. McAlpine regarding the testimony that I will present orally and briefly. Those two documents are a full statement of my testimony, and a recent paper published by Dr. Gustafson of the Argonne National Laboratory, dealing with the subject of short-range fallout from the 1961 tests of the U.S.S.R. The last two subcommittee hearings on this particular subject have produced volumes of information regarding the details of the method of fallout, the probable effects of fallout, and the various factors and ramifications that enter into this rather complex subject. At present nothing can be added to the basic concepts. 1Dr. Wright H. Langham has been associated with the atomic energy developmental program for over 18 years. The first 2 years were spent at the metallurgical laboratory of the University of Chicago and at Los Alamos developing mieromethods for the analysis of trace Impurities in plutonium, In Tate 2944, his interests were turned to problems of toxicology, biophysics. and radiobiology. He became the croup leader of the Biomedical Research Group of the Tos Alamos Scientific Laboratory in 1946 and still holds that position. His major interests have been tn the fields of physiology and toxicology of plutonium. tritium, and other radioactive materials: effects of massive doses of radiation on animals; relative biological effectiveness of radiations of different types and different energies: potential hazards of worldwide radioactive fallout from nuclear weapon tests; use of radioisotopes in biology and medicine : and radiation problems associated with space conquest. He is a member of the International Subcommittee on Internal Huzards of Radiation; the National Committee for Radiation Protection: the National Academy of SelencesNational Research Council Study Group on Radiation Problems of the NASA Apollo Program, the Radtlation Research Society, Health Physics Society, and the Federation of American Societies for Experimental] Biology. SSSRPOMBBINESeetSfGHEESHEETCRISTHEaaahLERET

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