OQ \ Cys Dr, John C. Bugher, W.De, Director’a - oS Wleooi, May 13, 195k os i oo Division of Biology and Kedicine”. by e 2 gordon’. Dunning, Health Phigeleist'” OCS os ee (TRE:eee a AOB7O9 , cae heAe, ok Oe Biophysics Branch,| Division of Bloloiy ‘and Ledtcine* DADTATION1OSE,70.STHEROID OF NATIVES FROMHORTA. _Ssmmaten) “4 ByE ACLASSIFIG,@,0N GANCELLED oS the gut after ingestion of fallout material. ‘The telluriuna, in turn, might disintegrate inte radioactive iodine while in the city To = ; os o}. there aro ‘sone “47 radioactive isotopes of telluriun but only” 7 of “sagas 4-S_ aa these are produced in fission, Of these, 6 are not of interest. . 3?( have too short a half-life, 1 leads to stable, iodine-127 and i | S| leads to fodine-129 with a half-life of 2- x 10? years), The . 2.2. AE renaining radioisotope i's telluriun-132, with a half-life “of 7 hoirs leading to Lodine-132 with a half-life of 2.4 hours. (Incidentally ig3) there is no tellium precursor that is of interestheres) . BR we te he Giithouthaving the original data of LASL I have accepted their.FE vii g estimat that there were ingested and/or inhaled the’ products «of: : oS mS 5 x 101 fissions, assuaed they were all ingested, and then‘proceeded - fo: AIPM) a fact that telluriun, asa precursor to iodine, may be present in est esnoch s ~ E ~ :¢tin 0% Bol -- a a = PSone. a Expos > 8 re This memorandum ds “tn reply ‘to your request foran“estinateof additional doses to the thyroid of the Rongelap natives due to the 8 of vi with subsequent deposition of the fodine in the thyroid.-oe 4 . COMMISSION cn fe ‘> Files CotectonDAM ‘ i US DOU, ARCHIVE: cal - “326 US ATOMIC ENERGY—-.’ im) & 2. aa & = ‘to calculate the dose to the thyroid from (a) i3t (b) each’ short~ 7 lived iodine isotope of interest and (c), the added dose coming from*-ae 7520132 The calculationsshowthatT132~{132 F421 produce Ee added dosage of about 26. WRESTDAA mee ce2 as a oe = toe The best estirated percentage absorption and depositsonof ‘Lodine istes yet to be determined, The best estimate I can turn up to date is | tean still the 20% quoted in HBS Handbook 52, Kowever, I will contime to” search for additional information, In the meantine the table below.’ indicates the magnitude of doses to the thyroid if one assuxes 20, = a 50, and 100% absorption and deposition. Incidentally, it may be pay oe oo noted that the calculations below tased on 20% (the,nusber assuned | ‘by LASL) show estirated doses to the thyroid from LI131 and from =~ - shorter lived Lodine isotopes to be in Bits agreezent withthose - estirated by LASL, i.e, 50 repsfor 1} and 80 reps. for short” sn_ ey ON EE ES Se r Vi. lived odine isotopes.ee a ED ee te ‘BEST COPY AVAILABLE =. ~ & ¢ CT 5 < f row OFFICE p [BMBPwbweeee leet pone, DUNNING::Mirack Wile 3 SURNAME > $ 5 DATE > EL .eo - osweno ee S Form AEC-318 : . Ls . o oo . | . ‘ovens m (3 ah “O-13-5h OT: {200 US DOE ARCHIVES aEID o a Seal ir &APPL9 (NTA hes , ~ _ Se . may.ee ra OE wee ee eeTill ‘eLescci-3 ore ~ | x