PRIVACY ac T MATERIAehL ll BReEeT TO IQVEND THs FOREIGX SERVICE Or Tee UNITED STATES OF aMERICA 6 April 1954 Dr, Rokuze Kobayashi National Instituve of Health Wolfare Ministry TOXYO Doar Dr, Kobeyashi: On March 26 we roceived two sanples of urine from patients at the Tokyo University Hospital, I am hapsy to te able to report at this time that the radioactivity of these samples is so low that the deposits of fission zrocucts in thc tissucs of the two patients can be acccoptod es well within tne limits of safcty. The resulte follow: —- 720 Cisintesrations Per minute per liter 1 - 510 1" vate on the iniivicual racio-isotopes will be telegraphed to ne in another fow days, It will then bo possible for me to be more quanti- tative in ostimetins the Gose from absorbed fission products, Eowover, it is most certain taat the storage of long~livot racio-isotopes is insi-nificent in these mon. As you know, the rate of cxcretion of fission procucts at any given tine after atsorotion bears a relationship to the quantities doPoeitec in tne various tissucs. The principal radiochomical constitucnts at this time *re Cue to Sr89, Lal40 anc the Rare Earths, Those aro isctopes which heve relatively short half-lives anc sre climinsatet fron the body with comparative rapidity either by radioactive decay or excretion, In the caso of these patients, Sr90 is most certainly an in- sicrnificant fraction of the total abeorbod radioactivity, The permissitlo urinary excretion, considering the isotopes involvec, woulc be greater, by e large factor, than the values roportec stove, T note that the newsnapors continue to carry occasional stato— ments of the Japancse invcesticators to the offoct that the prognosis for the fishermon is adverscly affoctod ty the fact that long-life bonesecking isotopes are Ceposited in their tissues, It is regrettable that tho public continues to be misinformed in this resvect. Certainly the results raported above argue convincingly that only minimal, necically insignificant amounts of fission or oducts have been nbosorbed into the tissucs of the two paticnts for whom results are available, PRIVACY ACT MA C0 tc TERIAL REMOVE D