- - ' ANNEX T0 ENCLOSURE ge THE FOREIGN SERVICE So OF THE SS © CA AMERI OF S UNITED STATE 6 April 1954 Dr. Rokuzo Kobayashi National Institute of Health Welfare Ministry TOKYO ° ~ | oo Dear Dr, Kobayashi: eo . _. oT , 7 pee ee ae ee oh : On March 26 we received two samples of urine from patients ~ at the Tokyo University Hospital, I am happy to be able to report at this time that the radioactivity of these samples is so low that «-. the deposits of fission products in the tissues of the two patients — can be accepted as well within the limits of safety. The results-:, follows . . eee Poo. a MASUDA, Sanjiro . nd —--:720 disintegrations per minuteperme DS liter en YAMAMOTO, Tadashi - 510 dis integrations ‘per minute> per “er _ liter. - 2 ne Data on the individual radlo-isotopes: will be belegraphed to me in another few days. It will then be possible for me to be more quantitative in estimating the dose from absorbed fission products. However, it is most certain that the storage of long-lived radioisotopes is insignificant in these men, As you know, the rate of excretion of ‘fission products at any given time after absorption bears a relationship to the quantities. *eposited in the various tissues. The principal radiochemical constituents at this time are due to Sr89, Lal40 and the Rare Sarths, These are isotopes which have relatively short haif-lives and are eliminated from the body with comparative rapidity either by radioactive decay or excretion, In the case of these patients, 3 £90 is most certainly an insignificant fraction of the total bsorbed radioactivity. The permissible urinary excretion, considering the isotopes involved, would be greater, by a large factor, than the values reported above, : oe - I note that the nevis papers continue to carry occasional . statements of the Jaranese investigators to the effect that the prognosis for the fishermen is adversely affected by the fact that long-life bone-seeking isotopes are deposited in their tissues, It 148s regrettable that the public continues to be mis-~ inforzed in this respect, Certainly the results reported above . _. argue convincingly that only minimal, medically insignificant ty amounts of fission products have been absorbed into the tissues - sy of the two patients for whom results are available. “Leos mo ° ~ 19 . . oe - Pepartmentpf Energy. ~~,