THE FOREIGN SERVICE OF TB UNITED STATES OF «MERICA PRIVACY AGT MATELY REL SVED 6 april 1954 Dr, Rokuzo Kobayashi National Institute of Health Welfare Ministry TOXYO ° Derr Dr, Kobayaeh.: On March 26 we rocecived two samples of urine from patients at the Tokyo University rospital, I am hapgy to be able to report at this tinc that tac racloactivity of thesc samples is so l-w that the Ceposits of fission procucts in the tissucs of the two patients can be accoptod es well within tue limite of safoty. The results follow: - 720 disintegrations per minute por liter - 510 n u tt n uw Jeta on tre iniividual radio-isotopes will be tclesraphed to ne in another few cays, It will then be possible for me to be more quanti-~ tativo in ostineting the dose from absorbed fission products, Eowever, it is most certain that the storace of long-lived raéio-isotopes is in-. si-mificant in these men, As you know, the rate of cxeretion of fission products at any given tinc efter absorption dears a relationship to the quantities do~ positec in the various tissues, The principal radiochemical constitucnis at tris tinc sre due to Sr89, Lal40 anc the Rare Earths, Thoso are isctopes whice have relatively short half-lives anc are climinatec fron the body with comparative rapidity oither by radioactive decay or excretion, In the caso of these patients, Sr90 is most certainly an inSicnificant fraction of the total absorbod radioactivity. The vermissitic urinary excretion, considering the isotopes involved, wouldé de greater, oy @ large factor, than the values roportedc =bove, Ionote tnirat the newsoapers continue to carry occasional state~ nents of the Japanose investicators to tho effoct that the prognosis for the fishormen is acverscly affoctod by the fact that lone-life bonesecking isotopes are ceposited in their tissues, It is regrettable that the public continucs to be nisinformed in thie respect, Certainly the resulte reported abovo argue convincingly that only minimal, mecically insignificant amounts of fiseion products have boon rbosorbded into the tissucs of the two patients for whom result WG@rBBPRilOGRoENERGY CLASSIFIED INFORMATION (NO RD/FRD/DOE-NSI) COORDINATE WITH: Depl- of St cepeeves th ROMOVED fore BEFORE DECLASSIFICATION RELEASE AUTHORITY: DOE/SA-20 4 BY D.P,. CANNON, DATE? Ushy ¢