-. © Dr, Jonn C ‘Reg Bugher, UeDe, Tisserehiero Divisionof Biology and Kedicing©" wh eyibe Gordon M, Dunning, secaikBeicist2! reSERBORoo. ee ‘Biophysics BranchyDivision|of Biology‘and Ledteine~ aoe at926383 J aie. ES BSTIUATED,panratiog DOSE, 70,TROTOF HATIVESFROMRONGETA ne Ma ba a & v- ; Ce é: weee RATT TN Se ONT eSypsae a ae This memorandun is “in reply 55 your eee foran estimate of. additional doses to the thyroid of the Fongelap natives due to the ssi Aion Ex eos ed vy vole : fact that tellurium, as‘a precursor to lodine, may be present in _* the gut after ingestion of fallout material. The telluriua, in er turn, might disintegrate into radioactive iodine while in the gut, * pwith subsequent. ae of the iodine in the thyroid.-= Bel Coe x 6 TT , . Ae Seu. There: are ‘some Wn radioactive ‘isotopes of telluriun but only. 7 of _ ae Ast “| these are produced in fission. Of these, 6 are not of interest... ota, Al € fp o wees there is no tellium precursor that is of interest heres) m \a Se - so TE oe a “i; S withouthaving the original data of LASE I have accepted their:weit ig ge oe. estimate that there were ingested and/or inhaled the products of ers = 5 x i108 fissions, assumed they were all ingestedi and thenproceeded: . he33 RG to calculate the dose to the thyroid from (a) 1131 (b) each short- — . lived jogine isotope of interest and (c), the added dose coming from*.= ~, .., ,TH32_7132, ‘the calculations showthat T132.r132 will produce an}: pleco "3 ey added,‘oenge of about,2he.ate peeaa iane zt = iy won? . 2 5 : a rae og wos Oy aS Sy RSM Ss . The ‘best estirated percentage absorption and depositonof ‘todine 1a2: yet to be determined, The best estirate I can turn upto cate is ee - Pm} still the 20% quoted in NBS Handbook 52, However, I will contimeto™< _. ° search for additional information, In the meantine the table below.SF indicates the magnitude of doses to the thyroid if one assumes 20, **2 20°" ~ 50, and 100% absorption and deposition. Incidentally, it may be |=es *, i Oo ne DESL AT: ee , . OFFICE p> SURNAME > DATE > BR. NNTNG =) cl.” f gtr SLI DY NNT eae sk Form AEC-318 - . © 4 Bee we Ii9 aoe cata Tiiiifies ity) SB. $. CCVERKHIAT PRINTING _— US DOE ARS gee . a andate reps, forshort=": “ Me OS estinated by LASL, i.e., 50 Seefor xt toe lived OEE LoaPi yt? * , and from ams . shorter lived iodine isotopes to be in BPs agreecent withthose © Ye noted that the calculations below tased on 20% (the nusber assumed _|-_. <.- ‘by LASL) show estinated doses to the thyroid fron i131 at ,i-/2. Capnain eee 00 ye renaining radioisotope is telluriun-132, with a half-life‘of 77 hots | 3 } leading to itodine-132 with a half-life of 2.) hours. Coeones eh Ya a 59(have tooshort a half-life,:1 leads to stable iodine-127 and Vv ” = o 4 44, {Sl leads to fodine-129 witha half-life of 2-l x 107 years), ‘he -eae=x sa a $6502 NGLASSIE IL, cn: GANCELLED PIES 24 5 US DON, ARC.a8 i 826 US ATOMIC ENERGY~. ' 1a2a endses wieSim0ta e re SP Pe,oe “oe oc . ae OE , 3 ks