~ OF THE UNITED STATES OF AMERICA paiyAcy ACT MATERIAL REMOVED 6 April 1954 ment * pay Or. Rokuso Kobayashi Nationa} Institute of Health Welfare Ministry TOKYO - Dear Dr. Kobayaphit OP 8 ° ‘ . = len Oe le alle te Me otsaaah othe On March 26 we received two samples of urine from patients at the Tokyo Univeristy Hospital. I am happy to be able to repore at this time that the radioactivity of these samples is so low that the denosita of fission products in the tissues of the two patients can be accr.pted as well within the limits of snfety, The results follow: 720 disintegrations per minute per liter 510 ” " " ft ” Data on the individual radio-isotopes will be tolegraphed to me in another few days. It will then be possible for me to be mor quantitative in estimeting the dose from absorbed fission products, However, ~ it is most certain that the storage of long-lived radio-isotopes is in- significant in these men. As you know, the rete of excretion of fisaion products at given time after absorption beers a relationship to the quantites ue~ posited in the various tissues. The principal radiochemical constituents at this time are due to Sr 89, LallO end the Rare Earths, These are isotopes which have relatively short half-lives and ard eliminated from the body with comparective rapidity either by redioactive decay or << cretion. In the case of these patients, Sr9O is most certainly an insignificant fraction of the total absorbed redioactivity. The permissiole PBqpMKeOwT] fleezs ma God urinary excretion, considering the Ssotopcs involved, would be greater, by a large factor, than the values reported above, 4 the fishermen is adversely affected by the fact that long-life bonoseeking isotopes are deposited in their tissucs. It 1a regrettable thot the public continues to be misinformed in this respect. Coartainly the results reported above argue convincingly thet only minimal, medic-lly insignificant emounts of fission products have been ebsorbed into th: tissues of the tre patiants for whom results are avails gee ee . “ng . “ ae Myer, sho Co eAbps coca 4 - %.: ceaousn PRIVACY AGT MATERIAL REMO \ or. rr ne hyp | ip. ma f I note that the nowspapers continue to carry occnsional statements 2£ the Japanese investigators to the effect that the prognosis for %, /3