GHkd ee coy cae Von bs vaags Pethpper cp tos etait. Z INTRODUCTION “dt ‘ a ye a de to i i ‘ lye ve oan ae pe yot Jaet: "ant bgar gat: vd Tyee ( AES , LAirgi j wh me gS " sf ai g th fytes Pods s e ttf. aie: ttt. uf sae Vr ie ws sagt a Hefee te TRG APD Cae E Hap i ‘ tap. ibe z raee tin pt ide rat brea ae tiat | ¢ t (Exposure to fallout from4 “puclear detonation) gr ¢ to an ‘aerosol formed in controlled nuclear fissign, results ina biolo “ica}. hazard bath fFom) a external radiation of the oaeand from radiation emanatinggem, a dt ternally deposited materia revious studies, YFindicatedtt at the ' shortaterm effects which a gar following a cnaened exposure,(i,¢ external and internal expog hive) result. primari. from the external|:Vata, tion, The amount of material ‘sufficiently great 9penetrate the.yna Lural i. filtering defenses of the living organism and produce immediate effecth \ ig.pecessarily associated with a very large amaur aeHye material, There arg) however, situations jation is of primary congern. of externa fades in whichthe|inyerhal f Such situat 9 fifclude the’ long-term 2: effects p roduced by internally. deposited isotop¢ omwith long radiogstive” . and. biological half-lives; long-term effects o Yetumulated small’ déses of short-lived as well as long-lived isotopes; and damage to indivigual” i tissues resulting from selective localization of isotopes, | In order to assess these situations, it is necessary to understand the metabolism of the fission products, i,e., the uptake, distribution, and retention in the body of the various isotopes which are inhaledand ine gested, While a number of the long-lived fission products have been’ studied,'* information is lacking in ve whiek first, on the metabolism of a very early fission-product mixture (which includes ortelived fission products) and secondly, on the behave ettanec raedpaaray F products competing in the beady metabolism withthe numerpuspinee fission products found in the spectrum. formed on p bombardmaaPor yranium, The behavior of an isotope administered singly may differ frp,theisotope taken ina mixture of fissionproducts, 4 we ao pes While physical instrumentation can be used to. determine:‘the ‘external dose to an organism, if is aot sufficient for calgulating the: ternal:expesure since complementary metabolic data aref‘lacking on‘the uantity’ of. internally deposited matexgial in particular Highyes and or Bans 4 and on their turnover rates as a fugction of the amoun$pregent inco ete;Eyal environment, rr ty ts utehiney In the present experimenter therclore, a direcp:gyaluation,; BS ty of the uptake and “intribugen of fission products deposited in nierna ly -|- ;