in mice as a result of expagyre to a dry-particle simulant incorporating 2eday old fission material,The simulant employed was composed of tracer amounts of fission»pxoduct chlorides adsorbed completely on dirt particles in a wide size range, The simulant was gene rated‘as airborne The simulant is, however, notémecessarily of the samechemical form as fallout which would tend torgpeximize the hazard as approximated here, Earlier studies have tras A the fate of two other types of ajmulanta— anionic simplant* and a ft slurry simulant,? The former’ ‘épresé ts the falloutithat might oce Mowing a nuclear de chation in’aes water, and the latter a detonationiin ‘a shallow harbor, The biological response to anexpogure to fallout i Adependent on the "properties of thée?carrier material, The results ob Hedwith the drysparticle simulant in the’ typea of aimulants prod ie previous studies,’ ’other copipayed with results obtained witH present experiment wereuced i ae ee ae oe’ + fi In orde stp assess the ‘¥al ; tive importance”of inhalation and ingestion ‘as modes 10des ofentry 0 for theMaspion products in sti Body, thaede particle EXPOBNEEs| we pel af aie : soa} K vey “+ ‘eal . veteta dl é poi ind yl ‘ ot ; i bavi thitgs rote ” ph aye # oghe it if at ut a Ry ise: The simulant was prepared from neutroneirradjated uranjum obtained from the Materials Testigg‘Reacitor, ° The mixture of fissiot-products was dissolved in JIG) and qdded to a solution of previously prepared dirt particles of Ambrose clay loam of less than’40 microns in diameter,®: The partig}g -fisssion-progugt mixture was eyaporated to dryness ina ball mill fo insure mixing, The resultant s{mulant consisted'of dirt particles With an average giameter of from'] to 5 microns With the fission products adsorbedon the surfaces. ‘The solubility of’ the activity adsorbed on the clay part{gles was 8 per cent in'water and18'percent in HCl at pH = |, The aniti@ls were exposed'to this simulant within 2_ after the removal ofthe irradiated uranium from the reactor, days ree 4D 4) ' tA \ « ‘ a wet * Materials Testing Reactor autorafervice PHIMips Perroteufh Go, Idaho Falls, Idaho, de S & aA Saal ze oa Pe AE . oe ths ‘fy tee rr Preparation of (heSimulans. Oe wy t $following, in} lation, ferty, bes : iw. EXPERIMENTA ERIMEN 1, and, the respo fe'e'to thig’ 7 ag { 2 i . bygavage ae . aeswet oe at Bde hh ein Phe ale BE TT Zoo ESal EeSeiciderPET ee, TRSFae ROS. simujant ’ as administere@s . mice mode of a f hinistration wa at on Me teeaaaiekiyCityeh tn Sy ae encountered as a consequenge of a land-based nuclear detonation. ws : ae le Wt eptas eg ta e t en ot i he tn “Te te Se ge gate enka le ya« al - ne Don ot ates Sanssenate. i Ra a=, tm ekee . a tee Sy 6 heal fi RT Rasaes 3Nab SS RD = ga hal redAORAA ai Hansr: AES “a ShesPh Set ih Paes cig ei EE gePecg Ela geeG oe particulates and representa,qualitatively, the fallout which’ tight be | '' UNCHLASSIFLED