THE OPK IGN O: J71C8 PRIVACY ACT MATERIAL REMOVED OF TH _ UNITED STATES OF ACERICA 6 April 195) Rr. Rekuzo Kobayeshi Nationa} Institute of Health Welfare Ministry -TOKYO Dear Dr. Kobéyashi: On Harch 26 we received two senples of urine fren prtients at the Tckyo Univeristy Hospital. I em happy to be 2ble to report at this time that the radioactivity of these samples is so low thet the deposits of fission products in the tissues of the tivo patients can be accepted es well within the limits of safety. The results follow: - — 720 disintegraticns per minute per liter 510 no " tt tt ata on the individual radic-isotopes will be telegraphed to me’ Lad netrer few days, It will then b2 possible for me to be more quanti- tive in esti:eting the dese from absorbed fission products. Hovever, § acst certein that the storage of long-lived redis-isotes:s is ingnificant in these men, . AS you know, the rate of excretion of fission products at any given tine ¢fter absorption bears a relatiznship to the quantities &c- pesitcd in the various tissues, at this time The principal radischemical constituents are due to Sr 89, Lal4O end the Rare Earths, These are isotores which rave relatively short half-lives and are eliminated from the bidy with cctrparetive rapidity either ty redicactive decay or exase of these patients, °r90 is most certainly an inn of tne total absorb: redioactivity. The permissible n, considering the Ssotcpcs involved, .wculd be greater, r, than the values rcepsrtcd ebove. Iornots that the nowspepirs cintinue to carry cecasional statesnts of tne Jaznricse investigators t> the effect that the pregnesis for the fishertan is adversely affected by the fact that long-life bsone~ sctking isotepes are deposited in their tissues, It is regrettable that the pudlic continues to be tisinformed in this respect. Certainly the results reported above ergue convincingly that only minimel, medically insigrificent -mounts of fission products have been rbsirbe-d into the tissuss of the two petients for whom results are available. PRIVACY ACT MATERIAL REMOVED