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Film Monitoring Studlee for determination of radiation exposure, -For the purpose of indicating the Intensity of radiation to which -- yersm & lare exposed, film has the advantage of being subject t o fewer accldente of the type giving gross errom in reading of indicated expoeures. Primary disadvantage is the fact that blackening t o equally biologically hazardous amounts of radiation is dependant upon the nature and wave length of the radiation. Xn practise this effect has been largely overcome. Typs K Eaetman Kodak x-ray f i l m made up i n the size of dental packets is used because of its great s ene it iv it y. Lead crom is attached t o film, making possible by differential density readings of developed film both outside of and covered by the lead crose, t o meaeure the relative amounts of incident beta and gama radiation and their quality an well aa penetrating power. With proper calibre tion readings ere made in r unlte or their equivalent. Suitable film holders were developed a sident if ic atl on badges for plant pereonnel. With each batch of films are developed o all b rating strips of the same film which ha6 been ex peed to knoM graduated amounts of glumne ra diet ion. Use of theee calibrating strips makes it possible t o compeneate f o r unavoidable variatione in development techniques a8 well RE batch developed variation in film sensitivity. The results of this standardized study have been used l a monitoring perBOrUX3l in all parte of the Manhattan Dl strICt, and a service div ls lon has
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Develcpent of Neutron Sensitize rs for Fila! Work. A photographic film packet has been developed surrounded by afoil Theee metals are een s it ive to Slov neutronsof cobalt, rhodium o r sil~oer. and emit beta and gam radiation when expoeed t o neutrons. If them badges are worn by suitable pereonnel, the human body with its high hydrogen content 8 1 0 W 6 dovn the fast neutrons t o slow neutrone which in burn a c t upon t h e metal of t h e foil. are attached t o the sides of vatsr containers which alao aerve ae a meam of elowing the fast neutrons. Development of Xmtruments for t h e Measurement of Radiation. Thus beta-and gamma raye are emitted which blacken the For the monitoring of locations theee epecial film packets The following fastruments have been deslgnad, fabricated, and plaaed in operation by this section: A n all purpoee (vane) meter f o r the meeeurament of betaand A eurface alpha meter. A built-in alpha meter for measurement of hand expoaure. Radon a i r measuring apparatus. Radon breath meaeurlng apparatue,. Thin window Geiger counters and dipping Geiger counters. BIOLOGICAL RESEARCH SECTIOR 1. Metabollsm of Polonium urinary excretion in both high and Lw dosage8 amounte t o 0.02 t o 0.1 psr cent of the dose per day except for t h e f i r s t day when the hlgheet dose ehowe thrae t o ten times the rate of excretion. The fecal excretion l e approximstely twenty times the ur:nary rate on the first day, rising t o eeventy time on the tenth day and sir times on the fiftieth day. The retention equals tventy-five
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per cent cf the cms in ter dajifi, fort ? five per cent on the fiftieth day, eeven per cent a t 130 days and 0.7 per cent a t 300 days, radioactive decay on the 140 day hau - life basie). polonlum in t h e tieeuee show8 the spleen, lymph nodee, kidney, bone marrow, The die tri but ion of and blood cell0 with the highest concentration in 10 &ye. the blood cells,tee tee, and seminal veelclea ehov approximately the same Following eubcutaneoua InJection, the excretion retee, in term of the amount absorbed, are elmllar t o thoee after intravenous edminiatration with the exception of a higher urinary excretion during the flret two dayta. About 83 per cent cf the dose remixu i n the body a t t e n days, of which about 40 per cent 18 retained in the iq j ect ion site. Ora1 studiee ehow t h a t 3 per cent t o 5 per cent of the dose is absorbed from the g astro - intestinal canal. excreted in the urine in ten daye. The fecal excretion is approximately the Fifty per cent of the absorbed mter k lle eame par oent of t h e abeorbed doee a8 in the intravemue animal. Skin absorption in the human subject indicetee that no ebsorption l e detectable In four daya of expoaure. The feet of mioe ehow lees than 1 per cent of total doee abaorbed over a two-day erperimantal period. By inhalation e Large proportion (probably over 30 per cent, and in eome cases approximating 10s per oent) of the vaporized polonium inhaled by arat 1s retained In hie Lunge. Most of tho polonium captured by the lunge is abeorbed into the blood steam giving ee sent i ally the effeet of an intravennue 1n;lecticn. Sufficient polonium may be retained in the lungs (11 per cent of the dose a t LO &p)f o r a prolonged period t o produce direct effects on the alveolar epithelium (see M-1811).
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B. Human SubJecte: Following lntravenoue 1nJectIon i n t o human eubjecte (four casee) In amounts from 0.18 t o 0.3 microcuries psr kilogram, the twenty-four hour urlne showed 0.07 t o 0.8 per cent of the dose. The average Qlly urinary output In the flret veek was 0.06 t o 0.24 per cent of t h e dose; In the eecond week, 0.04 t o 0.08 per cent; and a t 70 days, 0.02 per cent of the dose per bay. flret week amounted t o 0.56 t o 2.03 per cent of the doee; during the second week, 0.73 per cent; and a t 70 days, 0.25 per cent of the dose. The fecal Ql ly excretion during the rapid dleappearanoe of the Injected polonium from the blood stream wae observed a8 evidenced by only 1.7 per cent of the t o t a l dose rsmalnlng In In oral atlminletration of 0.19 mlcrocurles per kllogrem, the blood and urlne raluee were approxlmatelg one-tenth of the does found after intravenous injection of a simlLar doee. This indicated abeorptlon of less than 10 per cent of the dore. The fecal excretion amounted t o 77 per cent of the dose by t h r e e Qyr. A t the end of 230 day8 lese than 0.6 microcuries remained in the body of 8total of 18.5 microcuries given. number of eubetancee tested, only BAL (Br l tie h Antl-Lewisite) cawed a transitory rise In the fecal excretion several veeh after InJectIon. This lncreaeed output was balunoed by a later decreaeed output for e few days.In the fl ret 24 hours after IntraveaoueInJectlon of polonium, PAL produced a urlnary excretion of 5 per cent of the dose a s contraeted witha nonnal of 1 per cent of the boee. Following this, the excretion dropped t o normel level.8. BAL treatment Lmmsdlately after subcutaneous injection cawed no significant dlfferencea in the excretion rates.
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Tieeue analyeee ehowed essentially Blmilar conoentratlona, except in the spleen vhoee activity wag coneiderably lover after BAL treatment. 2 . Distribution and Excretion of Radium: Rats were injected v i t h 11.5, 16.0, 17.2, and 1000 microcuries per kilogram of radium a8 the chloride and followed f o r one, ten, and 9.3 t o 21.6 per cent of the doae; the fecal excretion, 0.18 t o 25.2 pew cent of the dose. The total excretion obeerved vas from 14.0 t o 44.0 per cent of the dose on the first day; a fall to1 per cent on the The urinary excretion on the first day amounted t o a i x t h day; 0.5 per cent at 10 &ye and 0.1 per cent a t 50 days. A t the ten day period, 40 t o 60 per cent of the dose remained vith ln the animal; a t 50 days, 32 per cent of the dose. An additional observation indicated that the excretion rates vere not influenced by t h e s i z e of the dose. One animal carried for 236 dap still retained 40 per cent of the lnjeoted doee. Distribution etudiee ehowed that a t 24 hours, 83 per oent of the amount reaminlag in t h e body vas deposited in bone; at 10 days, 99 per cent; and at 30 days, 96 per cent. The higheat activity found in t h e bone wae present in the t’rabeoulse. The g astro ln tee tl nal traot shoved 8.2 per cent of the total doee a t one bay, fall hg to a mall figure a t LO and 50 bye. dropping atthe LO and 50 bay periobe. a t LO days, and 0.002 per cent a t 30 dap. Oral adminiatration studies Other soft tis eu ee shoved 8.8 per cent a t one day, aleo The blood ehwed 0.005 per cent 3. Comparative Lethal Doae Studies of Radlum, Polonium, and Plutonium: Valng dosagee expressed ae microcurlee per kilogram, the short term lethal doee studies indicate that polonium is three times a s toxio as plutonium,
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and that plutonium is a t leaat thirty timea a a toxic as radium. On the basis of relative energies of the alpha particle e of these three substanma, it is apparent that f o r the radium and i t a daughtera, plutonium, the energiee per microcuries are approximately equal, the amount of radium loet from excretion being compeneated for by the retention of its daughter products. On the earn basis, the polonium/plutonlum comparison indicates that the former l e approrlmately twioe 88 toxic per u n i t of alpha ray energy Gissipated in the body for LO bye,five times a t 20 days, and aa high an 10 times at the thirty day period. Biological explanation of the difference8 mey be explained on the distribution of them elements, the radium burying itself deep ln the bone, the plutonium in the endosteal layers near the marrov, aa8 the polonium In t h e hematopoetla and lypbstic tlsauae themeelvee. The long tlma (sir t o eight month) studies of the comparative lethal dose tend t o corroborate the above findiaga. Pathological findinge indicate that radi m show8 an affinity for the hematopoetlc syetem, vascular myetem, liver, kidney, bwel, bone, and testes with damage proportional t o doee end time. the hematopoetic ByBtm, bowel and tertes only with (Irunsge again probably proportional. Plutonium shove ita aff laity for the hemtopoetic system, liver, kidney, bowel, bone, and testes. The changes observed with radium, although more vid ely distributed, are in gemral not am severe as polonium. A n unusual finding lethe development of far advanced arte rio e cle roe is of the aorta and Larger arteries including the coronaries. Plutonium tends t o shov i t 8 most Bevere development in the hemetopoetic system, Liver, ant
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4 . Dietribution and Excretion of Radioactive Materials in Non-toxic Doseb. Studies are being conducted on the injection of non-toxic amount6 of plutonium, polonium, radium, uranium, and possibly lead i n t o human 6ubJecte In order t o determine the excretion rate6 in the urine and f e c e s of theee materiale. These etudlee are not ready t o report a t the present time. Tbe information found from such rtudies w i l l be uaed In determining accurately the allowable excretion6 of thee6 subetame8 in the careful monitoring of plant pereonno1 working with them. The urinary quotient will indlcete the amount of harmful material preeent in the body a t that unit tlma. protein mstaboLisrn such ne In vound healing, repair, aging, mncer, 1. Eov eubstituted cuniao acide behave in the body. 2. Inveetigatlon of bone metabolism with an idea t o therapy, eta. b. Chronic eff s cta of alpha emitter6 over a ten-year pmiod. For UB in ohronic toleranue etudler . Additional etudier on radioaotive meteriala, aataboLi6m in general, part lou le rly with regard t o the item mentioned tn (a) above.