2 8 8 I10499i

t 7 143830 bTOI'IC __-z7zF(lY3EiT,FT--- TS - 4bDIOISOTOFFS

Q '1 by I

Paul C. !.cborsold, Th. ). ihief, 1s;topcs biwi s ion, Oak Xidgo Operations U. S .'Atomic Energy Commission, Oak Ridga, Tennessce 4 Address Bcfore The Teachers In-Service Cou:-sc on Atomic Energy . Thurd'day, -'-pril 7, 1949 . New York City

2 8 Evcryone, should be intercsted in atom. .ie are much more intimate' 8 with @toms than we realize. They make up all tho air WQ breathe, 311 the food we eat, our flcsh and blood and bone, and everything amund US - in fact, all the m3.tter in thc world, thc plmcts, the stars and. the far away galactid universes.

* Each of us from a nurely physical standpoint is a large batch of atoms. But don't takc this as being materialistic or derogatory. Far from itt For yov are an exceedingly mrvelous batch of atoms -- a vcritible Alice-in-'!'onderland world of atoms -- an exceedingly dynamic, almost bowildoring mcrry-gg-round of atom L I

0 Each person contains about ten billion billion billion c.tomS* These atoi zrc rrain'ly those of 2 dozen or two chemical elements Ench day you tako in ncarly a billion billion billion ncrv.atomq. and pUt out ' .about as many old atom -- atoms that your body hx becn custodian of for only a limitcd tim. Thc atom now in your body nre being roplaced by ncw atoms at an c?mziigly rayid rate -- nt such c rate that in anothcr ycnr most of the ctoms nav in you will hmc becn replacod by othcr atom. Atoms flow in znd out of your body -- in faot, in and out of evcry tissuc, indocd cvcry cell -- at such n paoo thrt by comparison the Times Squarc sub-?rays at rush hour would sccm likc siesta time in, z qu7in-k Mcxican t.own.

Bcforc wc &o into morc datnil :.bout thc terriEi.6 traffic of ?toms in your body -- fbr thnt mzttcr, the rc?pid -tomic turnovcr in all forms of lifc, in civcn tho simplcst: organism;; -- let us pausc for somc bF.ck- ground hforrmtion that m.y forcstill thc quitc justifiod unbclicfC you m.y havc concerning thcsc stnrtling f-.cts;

HOW do wc know all this?' Hov do VTC follow all thc f?.st'and cohpli- catcd manmvcrs that atoms enter into in our bodies and othcr coqlcx systoms? c

"hc answcr is that va c2.n now follow thc tricky mncuvcrs of atoms in ways hcrctoforc impossiblc. Atomic scicncc md atomic cncrgy dcvclopmcnts hr.vc givcn us povmrful new ntomic tools c?.llcd "isotopes"-- populnrly known as "trnccr" atom. ic can follow thosc "trwor" ntoms liko we can follow thc migration of "bandcd" or "tzggod" birds - likc Wc can follow thc dcaling out of "mnrkod" cards - or likc i'ro can tracc "labclod I' money.

I10499i. BEST COPY AVAILABLE But how do -;JC "bnnd" or "t?g", "mnrk" or "l~~Lbcll'on ?tor;? atem is so smll th:t billions of thcm could sit on thc point of a nocdlc. No onc hT.s cvcr sccn 2.n -.tom and no onc cvcr will, Thc ?&tom is vcry much tinicr than 3ny p-irticlc which WF.VCS of light c-n cvcr bring into dircct focus for our cycs to SCC. Thosctvhs hold th..t "sccing is bclicving" will h,:vc to takc thc atom on faith -- f. fD.ith bnscd on all kinds of good cvidcncc, to bc sure, but still by "sight unsccn". In spitc of this, wc cp.n l-bcl ccrtain ntoms and idcntify thcm, cvcn though indircctly, ?,s surcly 2s if thcy wcrc big cnough to SCC and wc had mrkcd thcn with bright rod stripcs.

To "tag" -,toms, and thcrzby usc thcm as trnccr atom, wc choose spccial form of thcsc ?.toms or spcciTtl "isotopcs". liny ono of th,C clcmcnts -- which in rcccnt ycvs hx grown in nwnbcr from 92 to 96 -- can zxist in scvcral form or spccics of ?tom, which diffcr in l~vcight.

Spccics of ..toms of an clcmcnt which diffcr in might arc called11 isc- topcs. Thd word "isotopx" corns from two Grcck words maning Sar[Lcll . and "plq.cc" -- n n:mc choscn bscausc thc atom, although diffcrcnt in wc'ight, still occupy thc SZITC plccc in thc tablc of clcmcnts. Sincc thcy arc -.toms of thc sam: clcmcnt, thcy will bchavc alikc chcmicp-lly -- their difforcncc bcing only in physical propcrtias e That is, isotopes arc likc twins thnt look -ad act nlikc but which arc diffcrcnt in IJCight.

bonrt think of isotopcs as somcthing found only in a lcborntory. Isotopcs arc comon in thc clcmcnts ?round us hLrc - including those * in our bodics. For cxamplc, hydrogcn, onc of the most abundant 010-. monts, cxists naturally in 'two for-ns. Onc is ordinmy hydrogcn, which has a might of approximtcly onc unit of atomio mss, called hydrogcn 1. Thc othcr is approxim!c'ly twicc as hccvy and is cnllcd heavy hydrogcn, or hydrogcn 2. Both of thcsc forms arc stcblc, th2.t is, thcy do not change with timc or disintcgratc l5kc t"nc rF.dioactivc atom ;vc will soon uiscuss. The;' nro thcroforc callcd stm.blc isotopcs . In hydrogcn ivcrywhcrc in n-turc thcsc isotopcs arc found 'in practically thc smc rclativo abuqdnnoo or ratio, namoljr 99.9% of hydrogcn 1 to only 0.0% of hydrogcn 2.

Othor comon clomnts of-ouy bo&j"&d our cnvironmcnt, such as carbon, oxygcn, Sulftll', chlorihc, potissium, cnlciun and so on, also cxist in morc thnn cnc st?blc forh, For cxmplc, carbon has stablc isotopcs of wight 12 cmd 13, c3llcd carbon 12 q.nd carbon 13, 2nd oxygcn has stzble isotopcs of,vcight 115, 17 and 18 (oxygcn 16, oxygen 17 and oxygcn la), In fact ninong thc st?blc clcrrcnts from hydrogcn, clomnt nmbcr onc, to bisnuth, clcr%nt numbcr 83, thcrc arc now knovm 284 stablo spcoics of atoms or isotopcs. A ntgxbor of tho clcmnts, such Cs botyllim, fluorinc, s odi'um, aluminux, phosphorus, scmdilti, vanadium, 1-ngnnosc, cob-lt and so forth, cxist in only onc stcblc form. J:ost of thc sto.blc clcncnts hovrcvd hzvc two or riorc st 3.blc isotopcs. The rolativc abundnnco of stablc &sotopcs v?.rics ividcly from clcmnt to clcmnt, but for any givon clcmnt thc rztio of isotopcs is pr-ctically thc Sam whcrcvcr thc clcncnt is found,

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I104492 Bct~nlly,thcrcforc, :vb ;1rc not just corm~s~d of %toms, but of T numbcr of diffcrcnt fomq of.itom., or is:topcs. Tfc ZPC com- posed of st:.hlc isotopos of hydrogcn, cvbon, oxygcn, nitrogen, CX1- cium, and so forth. Ilcncc, in tcr&, ,of physics, you ara. wt just 2 I i.. bntoh of atow but 2 brtch of "st-blc i60tot~cs"!

But this makcs no diffcrcncc t'o our body's chc7-ical rcactions, or to othcr chcmic*al reactions, bcc2usz 211 farm of the sam ClcmCnt bchnvu alikc chchiczlly. Stabl,: is otopcs can howcvcr bc diffcrcntiatcd or idcntifiad by physic .1 m,thods through their diffcrcnccs in wight. Thcsc diffcrcnccs arc not dctcrrnincd by scnlcs but by very scnsitivc clcctromignotic dcvicos calhd mass spcctrolnctcrs . Such dcviceS cm sort out thc atoms introduccd into thcm and rxaswc thc numbcr having any particular tvcight

During thc war tito 1-rgc scalc physical devices vcrc dcvclopod for sorting out is.qtopcs in quantity. Onc, tiic clcctromgnctic, is lilcc c giant mss sp,ctromctcr. Thc othcr, thc gcscous diffusion mothod, dcpcnds on'diffcrcnccs in thc way ?.tons of -. g.s will diffusc through a barrior picrcod by cowtlcss tiny c2pillO.ry holcs L Thcsc isotope Sorters call changc thc ratio of isotopcs of any clcmcnt fron tho value found in'n3tu-c by conccntrzting r.ny pzrtlcu-lnr isotope of a mixt?u-c. 'It is -tic11 known; for oxamplc, that the plxts at Oak Ridgo c 0nocntrr.t c thc uranium isotopc of wc ight 235 i This is otopo

cocstitutcs only 0.7% of ordinzry uraniwr, but is conccntratcd f-.r 1 abom thc n7tural ;bundancc to mako it suitnblc for usc in atomic bombs or atodic powcr roactors . Oak Ridgc's clcctromagnctic isotapo sortcrs havd' alsd conccntr:tcd qmntitics of som 125 isotopcs of over thirty stablc- clcrlcnts for rosoarah and apnlication in atonic scicnce.

Not only do wc hnvc isotopcs that crc stable but vrc also havc isotopcs that arc unst-.blc or rndionctivc. As you know\ thc phcnomnon of natural radioactivity wts discovcrcd in urclnium ores by Bccqucrcl in 1896, ovcr 50 ycars igo, It was soon obscrvcd that all the clomcnts hcavicr thcn st-bbc bismuth (clcmcnt numbor 83) arc radimctivo -- that is thoy cni$ various typcs of ionizing and pcnctrding radintion. Thc intcnsity of thc rndintion was obscrvcd to dccay with tim. Thcsc prdpcrtios, the crnission of rc?dP.tion Gnd thc dccny of intcnsity, wcrc l-

Uoms of the nctural rzdioactiva olomcnts mc uspilly found' in ti numbcr of forms -- thcso nrc hhc n-.tural r,-.dionctivc isotopcs'. ;fhcrc arc nb fcw natwa: Tadio-,ctivc isotJop6s of thc lightcr clcmcats, such as thc 5sotopc potnssim 40, blit thcsc aro not ?Lbunds.;lt. .Practiczlly all thi n?.tural mdioxtivc isotcpcs arc thosc of qlcrjciits -hc?Vibr than load..

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1104993 "? ~ curiC Fift;.Cn yca~s-.go, ,in 19&, it, wxi discpSorcb bx JOriOt ip Frclncc t4r.t man, could znkc 'ncw ,fo.m of atoms which cs,c not found in n-tum. By,bdnb:rd& thc YtGms :of ordin-,ry st-blc, clcmcnts with sub-tonic particlcs c;.llcd, ncutrons, it, was found possible. to chi.ngc thc -,vcight of atom a;tificilly. Thnt is, nm can ?Ut in or takc out sornc oE thc .,unit buixdiqg blocks from which qtom ?rc mdc using a &.rioty of iubtornic p,articlcs with which to bot:bL;rd ?.torn, *ob ficld qf "-,ton smxhing" 'dcvc lopcd.

Thcso mn-mdc ,atox ,zrc gcncrally quitc unst-,blc and, iiko natural sqdioq.ctivc isotopcs , thcy dis intcgratc by giving off TtOnic radi%tions, Sincc thcir wdiztims arc found to bc much likc tfiosq fron thc natur2.1 r3.dio?.ctivc atom, thcy rcprcscnt artifica117 -induced or nLm-r?ndc r-dioactivity.

It ,&.s soon found, using high cncrgy 2.toix-smshing dooiccs such as thd,cyclotron, that nan'czn produco radioactivc forms of tho ordindrily shblc c lcmnts ; For cxampfc , wc can mako radioactive

isotoics ' of hydrogcn, carbon, phosphorus, sulfyy, cxJciwn, irod, OtO. Thcsc arc 'ccllcd rahionctivc hydrogcn, rzqjicc, ct,ivo carbon, radiocktiw

phosphorus, or s imply radiohydrogcq, radiocarboh,*I radiopho

So divorsif icd &d cxtdns iv2 hxvc bccn tho mcthods , sf a&f ically transqorming 'atonas', thzt wc aro now ablc to makc mny mdrc rQ#OaCtim' for& of atom than thc ,nurn'bcr of stablc onos oxis ding in nnturc,, 49 mcntioncd ,previously, thr6 arc only 284 stablc form horn, whcI',cas now wc hnvc alroady idontificd 738 radio2.ctivc for~s,most of %iqh Iarc mdo qrtificnlly. Thc total nunbcr of rcdiQnctivo nn$ sCablG . 'is'otdpds'of'thc 96 clcmnts now knm to man totals ovcr 1000~

Sapo rndiorctivu isotopos aro quito unstable and livo on tb ~ avorngp only d tiny frnctiori of a socond. In contrvt, sw 3Sq n SO hstablc and live on thc avcrago. for ,pcrio&of, ycars tp',thqusandS, and cmn millions of ycars You will notc 'that r; hkvc said "ivo .on tho, avcrdgc". This' is bccauso all radimctivc a.kom ovcn of a singlo 'kind, with tho' ,shdcgrcc of instability,. do na.t diu simul;t?ncWSlY:- sop wi'll dkc soon and SOLD khr. , Ono cannot, prodict whpn wy, 9 &-tibulnr unstable aton will disintcgyatc or ,"dit", 3ugt asdtho CDSO for nico or n ' B&t whcn VJC hr.vc a 1p~g.cnunbor o$ unstablo atow WC can bredict q c acq~ptclythc t@c it will tak~on tho c?vcragc for any g5von' fro. op'of,'$hem to disintogrsto,. - c .( - e. 1 "*2 - 71 '* ' 7 ''I . -5 Thc tirab thkcn f&'half' of c grmp of unstnblc atom to disintcgrnto is callod thc "hclf-lifo", and it is p convcnicnt mnsurc-of tho rata

of docay 'of 'llifbi'* of'"rqdipctivo isotopcs. At the cr.d of tho first I half-lifc bcri3d 1/2 of khc at&s will romin; at fhc 9nd of,thc sccond half-lifc 'f/2 Df kc rcmindcr, 3r 1/2 x 1 2 cquals 1/4, will fcmain; af%cr thc thira hlf-lifc, 1/2 x 1/2 x 12/ or 1/8, will rcmain, do, Most of' tho Uscful radioisot3pcs hn.vc half-lives in thc rango from 12: hours tg nFmy ycars. Radigsodiun, for cxnnplc, hcs n half-lifc of 14.8

hours whih radiocarbon hcs 3 around 5000 years *a half-life of. -. -

-4- __ . i."- ._.-.. ------* '*

J 1049q4 I -a- .,

< 1jow let corne .back to haw,we can. use iSOt@pes as trT*er iLOmSe As we have .just seen, v?e.have a wide variety of both stable and radioactive isotopes *

Stable isotopes can be used 8s tracer atoms only if they are concentrated above their natural abundance. A concentrated isotope of anJr elemnt my be followed in a system by observing thc changes produced in the abundance of the isotope 3s normally found in the system. Rc isotope's abundance is determined with a ~ISSspcctro- meter. This method of tracing atoms is mlu-blo and has found considcrT-bla usc, but it is not as vcrs:-.tilc and as scnsitive 2s thc US? of r-.

2FLdioc.ztivc isotopes can bc traccd by thc radia-tiors thcy givc off. Thc radi-Ltisns ?.rc dotccted by scnsitive ?.tomic instrumcnts such as Geigsr 'cduntcrs. ':lhen the radiations cntcr a Gcigcr countcr thcy gcnerhts an clcctrical inpulse. Thcsc irnpulscs cnn bc madc to.producc . signals which may bc sccn or hcara or mch;nic,?lly ccnmtcd.

atomic. ir,strumcnts Grc.so scnsitivc thct thcy czn dctcqt 2s CX- trcmcly small rtmount of rcidionctivc atoms, somtimcs as 1ittlC ?S a . -, billion billionth of cn ouncc. I_

Th,? vcry grcat scnsitivity with which radioisotopcs can bc dcT tcctcd is onc of thc rcnsons for thcir grcct mluo 2s traccr atpm. .- Take for cxamplc this little pinch of m.tcr'ial which I haw! in this vi21 hcrc. It rcyrcncnts 'L typical shipmcnt of radioactivc carbon, ths radioisotopb carbon' 4, qrom Oak Ridgc. Tho radioactivc carbon r.tom-tlre in th carbon of calcium carbonatc, Thc rays givcn off by , cnrbon lk cansist only of clcctrons and thcgc arc of such low cnergy that thcy cznnot oven ponctratc the glass wall of this vial. (Carbon 14 is thus safc to handlc whcn it is oncloscd c.s it is here.)

r? Yet this small frac-kion of an ouncc Df m-.tcrinl could bc mixcd with, that is diluted vhth, 5000 tons of normal stable carbonatc, 2nd. '*'

wc could-takc a+spaonful of thc final mixturc. and stiql dl=tcct..thoI rq.diocnctiv5tywith h Goigcr counter. To put this in t crm for thc . biologist, tho panoh cf intorial; hcrc ,aould hc uniformly distributed. ' in thc bodi'ss of 502million.,rats ?ad yot wc could .dctoct thc radio-' -

activity in 2 3inglc kat.' In athcr wo'rds,' czirboh. 4 can bc dilutod ' I with ordlfiarf Wto&sl. 50 xr&Lii.on tims 2nd. still-bo dctcctcd.

This littlc bit of niatcrial rcprcscnts wh2.t FVC call a millicuric, or 1/1000 of a curib, thc unit of n?tural rzdio?c.tltri%-y fimncd 'Iftcr Ibdm Curio. .In this millicurie amount 37 nillion radiocarbon ?toms nro disintogr-.tingcoch sccmd. But Carbon 14 only lqscs half its rzdioactitrity in ?.bout 5000 ycx-8.. Thus this g$mplc ;si11 still bc ' : disintcgr-bting. 9.t h-.lf this rntO, or 18.5 milli.>n disintcgrntions pcra . . sccond, TOO0 ycars frDm nave ., 11 ., * This is cLn cxtrcmly busy littlc pinch of r,ir>ttcr to g3 on dis- 1 integrating at Such h trcmcndms P:tc for thous:n& of years:

I104995 The energy. given off by this carbon 14 whs a11 obtained while it was being produced in the uranium chain reacting pile at Oak Ridge. The tot21 amount of energy emitted is extremely small, however, and is of no practical importance, purely from the energy standpoint. It is importcant however for trz-cer purnoses because we can detect and follow the radintion with such extreme sensitivity.

The sensitivity of detection of radioactive atoms is nillions to mnny billions of times greater than the physical or chemical mans for measuring itoms th-.t heretoforc hzvc been at man's disposal.

But this great sensitivity of detection, as iqortant as it is, ia only ono of the useful properties of isotopcs. In addition, isotopes *provide us with thc uniquo ability to follav a speoific batch of atoms through a cpmplicated systcm,irrospcctivo of all the other atom sent and of all the chemical proccsscs that my bc:going on.

By putting a little acid on this sample of radioactive carbonate, for. exaqle, VJ~can obtain radimctive carbon dioxide. This particular batch of carbon diaxidc atoms,cc?n thcn be fed to a plant (or introduccd into any othcr system), Thcn, whon,thcse tracor carbon atom' becom incorporated into complicntod molcculcs, such as Starch, sugar, . or protcin, WQ will know that thoy como from this particulat. batch of carbon dioxidc a&inistorod today in a spociffcd my. If wc had given ord*ary carbon dioxido to thc plnnt, wo could not toll thesc chrbon atoms from tho carbon atom alrccldy proscnt in tho plant. On Chc othc? hand, boonuso of thoir ,rzdiaaotivity, thc ccrbon 5 atom in this .vial ara 1abalc.d or tqggcd wkicrcvcr thcy go. , 1% is this combination of grcat sensitivity of dctoctiori with tho. uniquc bbili'ty to follow speoific atcIms that pcrmits isotopcs -bo provide us with ncw potvors of porccption, with now powcrs to acquirc knowlc dgc . .. It'rcprcscnts onc of thc groat cxtcnsims in our ability to pcr- ccim and to discrixinatc, tlqt is, in abiliky to "&cot' and to "s'3rtt'. At first wc could scc things on1y:with OUT unaidcd eyes and sort thCn out only with our hmds. Next, mn uscd mgnifying'glasscs and small tvfcczcrs, L=tcr hz invmtcd thc nicr?scopo to SBC finer dctail nrid bo lopcd ohcr$.cil, physical and bialogical pitoC~sSOS to difforchtia nd 'sort out various ele.mnts, conpounds and form of 1ifO.. Continyous improvomnt has bocn mdo omr the yoirs in 'ihc pbysicai, chcniea3 and @ialogicalmcthods ' 4.

.L ,I UO& rocdntly olcctron riicroscopcq have bocn dovolopod which oxtcnd ow ;sovrcr to s.oc dorm to thc sru1,lcst form of lifc, and cvcn to viruscs and giant riolcculcs which arc on -&he bomdary linc bctwccn living and inaimto :?attcr. Spocinl ccntrifugcs such as tlic ultra- ccritrifugc havc bccii dcvo lopcd which pcrr,zit us grcntcr dis crinination in sorting out molcculcs and qcl.ls, and CVCE parks of cclls, Othcr nothods such. P.S that of c lcctroph3rcs is, Ihich mkcs usc of olcotrical forcos on nolcculcs in solution, haw also bccn dovclopcd to furthcr our povrcr to disoriminato bctvrccn vnrious types of rnolcciilcs. - 6- to hnd nwr as :& furthor stc?, in cxtondrng qur c:'"s &nd hands study fincr and filler dctails, qc, &vc :hc trzcar iS;)tOpQS. Thcso :.l?ow us to' R~~~"3r Tc11Jm sr,xbll+r u,;ounts of CLLSI;~~thzn cvor boforc possible and t2 s&;t out p:r$icu$f L.ct*inns Df Li.tor.ss cnd c?c1cCUbS.' *. thc.t could' not bc diffcrcd ;rLtcl>iq 2w.y othcr

, * 'r Bcforc going on to toll y?u h& rnr;ioisqt?n:s 2rc used, I had bcttcr tell you ho;r tksy -&re mde. If x-rc tzk? clmost ".ny of thc clcmnfs around us hcrc, such as carbon ,or phlsphorw or sodium, or irm, r.nd :vc put it i::to tliz -..l;?r?ic rcJ..otor or pilc at Oak Ridge, it ca!: bc mdc to bccr,mc r-.Li3-.ctivc. For cxaqlc, you could gi-rc r.c a pcnny 3r 2 Zinc 3r r, b3bSy pir, 3r thc phxqh'rus on thc hcxd of 3 :r.tch, or any othcr 3f 2, widc vnricty of ri>tc.pir.ls c)r objects, znd wc can put thcri in 2. si,cll aluminun tubc, such as thc on0 I ham hcrc, 2nd thcn introducc thcn int3 thc Oak Ridgc rcactw. Imido the rcactor ivhcrc thc ur?.ni&T chain-rcaction is tc-killg Place thc tube and its cor,tcnts will bc given EL trcmcndous bcmbar$rcnt by thc subatmic nuclcnr particles, c?.llzd ncutrons . Thcsc nrc alsp thc particlcs which kccp the ChaSii-rcactiqn going, Thc rc2ctor was cl-signcd SO th7.t thc chain-rcactim Gail bc kcpt going and thcrc ivill still bc cxtrn ncutrons ' amilablc for othcr pUrposGs, Thcso ncutrms, bcczusc thpy aro Un- .' . - chargcd particlcs, have the ability tr, pcnotratc vcry easily into thc nuclci gf ntoms,' Bdditim 2f noutrms t9 nuclci causcs thcn to undcrgo atonic transformtians which rssult in tho productisn of radio2cti-m *' - isotopcs.

Thc chain rcactor is ablc ta produco radiocctivity in amounts

' cnrmxously grcatcr than could bc produccd bcfx-c tho mr by mms of thc cyclotron. Thc mounts of thc wriaus radio?-ctivo isotopcs produccd with the pilc arc thousands t3 nillions cad sometines billims of tilncs thc amounts produccd przvi2usly. Also pilc-produccd radioisotopes arc to a cortzin oxtcnt byproducts of atonic research and dcvcl3pncnt, honco they can bc mdc quitc chcaply. Although rzdic- activc tracor atDm had bccn produccd m,d uscd bcforc thc Tmr, thoy wcrc prsduccd mly ir. sm11 angunt and vmrc CX~CIIS~VC, Thcir USCI.~~~ hcncc quito linitc'd. At2xic cncrgy dom1opmr;ts hnvc nox mdc thcso cxtrcmcly mcful togls actually amilp.blc fsr rcsozrch and application on a vridc smlo at lm cost. , ,

kncd with this bnckgrounc',, lct us nw sco haw wc usc Cracor 5 atom Lct us takc f3r L sirrplc cxzripJc, radioactivc sodim. A11 rrQ 'havc to do to mnkc som radixodiun is to takozsarq tablc salt and irr2dirto it in the pilo, VJc could givq s~m:'F tb rndionctivc sodium .to a pors5n eithor by mouth 3r bJ voiq, (Slide-l), and thcn by nicam 3f Gcigcr countcr fin?, mt-hw rapidly it trnvcls thr3ughout thc b3dy, nnd thc ratc zt which it is t::lrcn intq m-rims b-?dy fluids ?ad tissues.

l?c find fw cxnqlc th-% thc rntc at which s~-Iiw,igxs ?.cross tho b1q-d vcssdl 1~11sis vcry rapid indccd. Thssc s,tudics h:.vc shD;m that 'Sbc'iun passcs bzck and fsrth xrqss th b13d wsscl wnllp at thc rztc .xf 50 p3unds of salt a c!ny. Thc rntc f cxchango -,f s?ditm (+ a- ?.ny

I . -7-

remaining iistancc coch timc. Thcorcticnlly onc vould ncvcr gct to tho ~~11,but for all practical purposss nftcr :,bout fivc or six of thcsc half distznccs (or h-lf Fcriods) thc goal is rcnchcd. Thcorcticnlly wc still h::.vc 2 Smll pcrccntagc of thc s~.mcato,m in US that wc h:d VhCiI 'UJ~ vrcrc born, but ?.ctuzlly this pcrccntzgc nust bc cxtrcmckj sal?. In 3. yc2.r most of thc :tons in us now, (2.t least 385 of than) will havc bccn rcplaccd by othcr atom that 1;rc takc in in our nir, food and drink.

Thc body is hcncc not just an cnginc that tckcs in food, zir 2nd mtcr 3s fuc1 to kccp running on. It ?.lso USCS thc ltoca tnkon in for r?pid rcpl-.ccxnt of thc ?.tors x.!.-ing up its p2rts. I-L is lilcc 2 loco- motive tk.t 1:Jould t.-%koin co=l 2nd othcr E?ttcri?Lls and nat only uSC them for loconotion but for thc continual rcpl3ccncnt cf cll its pnrts, 2nd at a vsry rapid rntc.

Of coiirso, vrc hnd :novn~ proyiously thr.t thc ?.tom of thc body undcrgo rc?lnccncnt, 3.nd that thcrc is quitc :. rnpid rztc of trmsfcr of atom, molcculcs and fluids throughout tho body. gowcvcr, by using trr=ccr <-tarns im h:.vo bccn ablc to find aut thnt thcsc processes arc much 1;loro dynnmic 2nd. cornplicatcd than wc had supposcd. It is bocausc of the ability to follov; such dynamic cxcliangcs and procxscs that traccr atoms arc so uscful in biology and ncdicinc. Furthcrmorc, xithout thcm vfc could not fcrrct out and untangle son= of thc vcry complicntcd proccssos .;Jhich go on in biological systoms.

In rcgnrd to thc terrific rato of transfcr and turnovor of atom in thc body, I an rcinindcd of Bob Xopo's rcaction to tho amzing feats of his body. I qucto: '!Today rly heart bcat 103,389 times, my blood travclcd 1~8,000,000 milcs, I brcathcd 23,040 tincs, I inh2lod 430 cubic fcct of r-ir, 1 spokc 4800 words, moved 750 mjor nusclcs, and I cxarciscd 7,000,000 btain cclLs. Boy! rj? I tircd!" If Bob Hopc lfflo~ tho pnco at which atom wcrc coursing up 2nd dolm md in and out of his body, hc might fccl hc ins on thc vcrgc of coqlctc collapse!

Yct, hcrc is thc ai-nzing thing about it. 'Lc Zon't quickly go "all to pot". Outtmrdly it docsn't sccc to hzvc much cffcot 3n us at 311. That ;'JC gct "out of order" once in a uhilc is not surprising. Thc mrvclous thing is that :E st-y so wcll,

Although nsxt yc-r you xi11 bc alnost a c31"?1ctcly ncxr batch of atoms, you won't bc; a ncw pcrson (xhich is your OI~fault if you arCn't!) Yqur "supcro31osstLl" traffic of :tops d,xs not takc placc just by chcncc. It is vcry cnr:sfully rcgula-tzd nnd controllcd. In gcncr-1, tha atom do not gct vcry fzr off thc i-izht rqad, cad thcro ?.re no trzffic Jam. Noxt ycar -;a vri11 c.ppxr vcry nuch thc sam as wc do now. Evcn though nost of thc :.tors jn 2ur brc:in vi11 hczvo bccn rcpl-.cc;d by othcr 2toFs, wc mill still g3 3n rcxcxbcring things th.?&t happoncd r. long tint 3g.3. Also our c:iotims, rmsoning, pcrsmali-by and individunlitj. g3 3n rmch thc szrx. Phyr;Fc?.lly ;7c t:?.y bi m:-r batch 3f ?tQm but uilfortunatcly, pcrhaps, wc c.rc 211 old batch of ei;istions, idam ::nd rcactixs.

In fxt, ths r.nrc studjr living things, thi: imro wa study a11 of naturc, inclLtair_g tlx zton itsclf, tilo iiord iic cnn scc that cvcry- thing is ngt just c: m,.ttcr of C~PJICC. For cxrmplc, figurz gut thc

I104999 .A I I_

a 'r L , t' 1.

chmcc' that somc protoir. mlcculc, or smc hormmc, 3r vit?.-nin 31' cnzp, 1-c.s goftcn togcthcr by thc ncrc chancc'nccting af .:ll its coqonont ctor?s Dut of a chaas of ntaas. Such rnlcculcs 2rc sa c9qlcx that cvcn OVCr thc pcriod of bi.llims of pars sincc thc carth I-~Sfanrcd, it is still cxtrcmly'unlikclj. that my such molcculcs would bc fgrmd by pW0 cbnco. It is cvcn mrc inc2ncciEblo to bclicvc that chnncc can 2ccount for All tlic hundrcds 9f thousands of typcs ?f mlcculos thzt occur in'naturc, for all thc cxcccdingly dynamic and cgqlicatcd proccsscs in which thcsz nolcculcs tnkc prt, md nuch 1csz fsr al1,thO ri?.rvo Is 3 f biology .

l.*?tv lct us SCC hsv we can USC trncor atora t-, study thc actim Qf noloculcs mthcr thin 3f just sirtplc clcmnts. To cl3 this i-rc nccd t.:, inc

stigntc this', rcsmrch wrkcrs hJ-a synthcs izcd cmino acids such as nothibninc ,. cyst inc nncl zlutathionc containing rr.dimctivc sulfur .and h?-;c fa'd thc lzbclcd hFtzria1 to rats. After thc lzbclod cmpound tcrcd. inCo thc bqdy rccotiy, thc anim.1 is sacrificcd. Itadils- ty &clysis 3f' varims tissucs such as thc splccn, livcr 2nd kidncy will indiozto r-rhcrc thc radiJnctivc atms motprincipally locatcd. 111 additi321, 'biochbmical an?.ys is will b-dicats thc chorxical form b c. which thc sulfur now cxists. Smc of thc sulfur will bL found in protcin, r;nt';oli.inl, s3.m in unconbinod zmino mids 2nd s xic in brcnkdavn ' propUct.S of tho anir,m,acids . In this way thc investigator dotarminos what' hcppbncd to the originally ingostcd ariino acid 2nd xhat its rolo is in thc body. .f

Exprimnts likc this clcarly provo thct our bxly 2roccsscs ?.rc continu?.lly brcnking. dnvn and building up .srgcnic nolcculos - Tho brcaking dcwn praccss 3r degradation 3f conplcx nolcculcs rclczscs thc cncrgy which is ncccssary f2r prqmr functilning 7f 3ur bqdics. It als3 furnishcs som of thc lcss corirplcx units which arc uscd in buildillg up or synthcsizing khc mom c-lnplcx co.riponcnts 2f mr tissuo. A fino bnlnnoc is rnin'taincd bctvrccn thc dcgrndati3n tj obtzin cncrgy 2nd tho synthosis t3 rcla ncw orgmbc r331cculcs f3r 3ur bgdy's nccds. I. ?.

.I I; -. .. ..' .. i!cxt. -:IC sz,c F.: s i~T,ilF.r,cxpprir?nt,;(Sljdc 3) .in .~.~IiicIi:--.dix.ctivc c:-.rbsn is u6c.d t-, lqbcl" stZr3iq mlcculus, Stqr?ids ?.rc :*. class. Tf . c:T,-ipl

livcr inta. tlic intcstincs) ClliJ SCX h,)rr,isnes; AgF.in thc f,:.tc ,.If the , ' lubclbd nctcrial is studi;d in nnir.r.lS by not-ing wh?.t :r,q.ns 52.l:~UP thc mtcrial ?.nd what ciicr?ic:\.l ch?.n.ngzs tnkc p.l+cc in thc .rigin21 . . l:.bcl;d xtcrinl. Zcrc ~1s3studics raf 3 disc?.sc slich 2s oc?nccr zzy-bo i:,?.dc by invcstigating thc diffcrsp,cc bctwcer, tlic.f:btc .3f thc lzbclcd- : stcrDi?, vhcn fod 't~an.ani;cl -;Jith cr.nccr 2nd t:>an mirnl :iith?ut- : > cxicor. Such stuclics xi11 give p.lucblc inf:;rr:.iatim on thc fmctimi' .: : r,f stcr3ids in nsrr.nl individwls 3s wll ns thcir rclatinnship t3 mri -)u~1cind.s -f cnnccr.

onc. ?f ;$hc, s?st i:ii:'.cly uscd rxthocls t? clatc in stu2ying.canccr: : L c :nsists .f $urpxc~,prx~ucingan cxpcrimnt:.l caccr in pLn miml 2112 thcn s$udying thc bi:7chcr>istry >f thc canccr and its offcct m ..,.

thc anjml. .Thcrc arc hundrcds ,?f orgznic coq9uids which x.:r bo "I .. .. uscd. #~..canccrprsducing zgcnts RF.diois3tQpcs r~lybc uscd .b~hbcl .I sAch bx~iprpr'3ducing zgcnts 2nd ta study thoir nodo. of actinn. For.. insti.&. (Slide 4), r.i~tli~lch?l~.nthronc,mc Jf thcsc agcnts ;hz-a bccn laiclad -.vith rndixctivs carbm. A skin cancsr is yrxluccd by rcpcrltcdly p:.intinL thc l?.bclcd agcnt c;n thc shavcd skin ~f the anirz.1. Sore jf thc ?.gent :xed in prTduciqg thc cGnccr ,vci11 bc found incorpmt.tcd in.thc .cmccr but s 3r:c rl-f it vi11 h~s-cbcon brgkcn d0-m into 3thcr .. piobucts . Tho locc,ti.m ;f thc "Sent an< its brcnkdmn products cqn bo. J studied not mly in thc c?+iiCcr but in .zll thc othcr tissuus . Studies t. 1 of this typc will brna?,zn JUI- mcr-?.ll lcnmlodgc 3f canccr and tho mom ~c lczrn..abaut tha poculi-ritics 2nd cli:rr?ctcristics'.of this Sisczsc, thc bcttcr cquippcd wc will bc t3 cxbnt it. ;. '- .I.. Thc ncxt illustr?.tim (;lido 5) sh~wsa radigisA3pc cpplic2ti-m which was very vcluablz' during ths -"mr. It is thc usc of rC?dix.CtiVO irm in studying thc cffcctivcncss Jf vhqlc blTx1 prcscrvntivcs

Tb radixctivc iron is first :fixed irith cm!in-ry irin and put into c. choniczl f 3rn sujtablc f 7r 2.rhinistrntim to 2 prxpcctivo bl~iG--"m~r.It is thcn injcctc?, icto thc vein 2f tho clmx's arm in snall c'cxcs svcr a pcriqd of tw:, to fqur :reeks. AfCcr this timc S~Gqf the rF.di3irm is fguncl Gcnrporatcc! in tho hcnnglobin (irm containing red pigmcnt) 3f thc circulating rcd +lc~>dcells. It has bccn aktihtcd th3.t in thc-tagLzcl 3r l~.bcbccdrcd blq2d cclls thcrc arc only mc tn tcn radixctivc inn atop t3 ab?ut 3 thmsand nillim 2.tnns of 3rdinTry irm; yct thc sensitivity ~f';thc mcth?c's 9f mcasurcj:~nt pzrmits c'ctcctj.?p 3f thcss l?.bclcd cclls with cxtra- 3r C! i.n~-,ry :zc c urmy.

Blo'3-' cmtaining thc t?ggcd bhod cclls is ranmcc? frm thc d'm3r p-nr: rixcd .rith thc prcscrmtivc to be tcstccla This bloxl-prcscrmtivc mixturc is thcii storcd un:cr: wrj3us conditimc frvcrying lcngths of tinc. hx-in,g tho vrartim invqstignti ms, b,lr: Id-prcscrmtivc nixturcsr~' m-rc ship?&? t I c'istant p-)ints, tc rhqlic~.t,,ficlr! oonr?itims ant! thcn

rcturnzd t2 thc rcscarch ccntqs f'gr tcsti:!I;. +

-11- l1OSOO I i' Thc prcscrvccl bl?x! cryrtaining thc 1Abolod cclls is thcil injcctcd int 3 thc blq3d rocipicat. FollowSng~thctrznsfusion, bl ~QCIscnplas xrc rcn7vod at apprgpriatc intervzls from tho rccipicnt an? ncasurcd f>rthcir radimctivi'ty t? dctcrminc th2 nunbcr 3f l?.bclsc! cclls that hnvc survivod. Diminishing r-dioactivity in suoccssivc bl idt sanplcs indicztcs thc rato 3f brc3k dwn ,f ths dm9r cclls and. thcir loss from circulation. During thc war nun arbitrary1 rulc vas nd3ptcd thzt survival qf 70 pcrccnt qf thc transfuscd colls fqr forty-cight hmrs rnuld bc acccptablc anc! that survival 2f 90 pcrcont or rnrc of the cclls ??uld indicntc cxccllcnt prcsormtion. In this v&y thc ncximum uscful lifc 9f prcscrvcd vholo bled IES clctcrminc$ :nZ nothods dcvclapc?t for cx- tending it.

Othcr blo?d. stuc?ics h?vc zls? bocn carried >ut with r?,'i3fron. Thcsc studics ha* bccn dcslgnod t? invcstigatc thc body's nccd md' usc 3f irm (Slidc 6). Such studics hzm bccn carricd out prim.rily on dogs. Rcsults obtaincc! t3 dato havc sh?vm.thnt thc b3clJr's USC 3f

irin is mxltcdly difforant frm its usc 3f most 2thcr clcncnts. hs I prcvi-msly n?tcd thc bo.:y rcac!ily ::bS xbs "ncv?' sodiun apd. blinin?.tGs an ?.pproximtcly oquimlont znciunt of n~lctltsoSiur?. nith Irm, hmcvcr, 'as prmoc! xith r-.ciiois.stD?c c'pcrimnts thcrc is nqrmlly vcry littlo. iron absx-bcd fron tho dict - thc iron bcing absqrbcd mly -/&en ncc2,od. Usuzlly this nccc? is vcmj smll whcrcns in cnscs Df ~ncminthc nccd will bc grcatcr. N9st -zf thc irm c-t fmnd in circulc?ting rqd bloq6. colls is stmcd in thc Livcr an", splccn. It hzs also bcm shm tk-t iron for ncw red blosd colls is chiefly supplio? by old rc2 blaTd cells, tha* is, 2s tho ald rad bl-3d cclls brcak up tho iron is rcuscd rathor than gDing t3 tho iron stoEgo sitcs.

Not mly aro radioabtivc tracor ato-nls boing uscd tJ hclp fcrrct out thc intimatc an$ cmplcx biological prmcssos cd life -- in gzining ncw mdical knDwlcdgc -- %ut thoy arc-also bcing uscd t2 asccrtz-in what is wrmg with ccrt:.in b3C1.y pr3cosscs, that is , t3 dingntxc discXC an6 injury.

RmLc?i-.nctivcsodiur.1 for izfstanca (Slido 7) may bc us or^. in thc c'iqppsis qf mriws blc~,odairculation r'is~rdcrs. #If n lczbclcc't salt salt sqlution is injcctcd' int? :: n'~m1prsm, the circulzting blood will quickly -nc! cqunlly cXstrfbutc thi: sodiun t? both logs. Vc can lcarn this by cking'n' G-cigcr c?untcr up ax? S.mn cach lcg and finding approximto ly omst?.tlt ;rac'.%ati?l? ra?&c?ings . I On th3 9thcr hand, if tho countor ineiicatos SI? ibscncc ?f ?adi?r.ctivity in h cortnin moa, say thc loft lowcr log cad foot, it shms that ths blml h2.s n3t czrricd thc rndiTisstqpc tq th?.t nrcn at!, thcrcf?ro , thcrc is. an inpnirmnt 3f' thc circulatim. K survcy with thc Gcigcr cwntcr will l3calizc tho woa Tf thc inpairmcnt sr cmstrictirn. This c!iaL;nxtic tcchniquo has prvxct s? rclicblo thct it hns'bccn UCi' tq btcrminc whcthcr rlr not it is necessary to aqbta'te and if' mcessary where t~ make the aniputat ion.

Radioactive sodium is used in still knother way 2s a diagnostic tool. In this instance the ?urpose of the diagnostic technique, known as radiocardiography, is to dotermihe the pumping qualities of the heart by recording the passage of radioactive blood through the chambers of the heart. I105002 - 12- Zadioactl-Je sodiun is introduced iii~othr vein of the p:trent's am, from iJllence it goes directly to t!le 5.eart. A radiation detector connected to a special ink-writing rccordcr is ?laced outside the body over thc heart., '.:'ihen the radicactim sodium enters the chambers 'of.the right slde of tho hear?, thc rz.di;ltion picked up by the detector cnus'bs the recording pen to risc sharply. The pen continuds to rise in th? .dase of a normal hcarf for about one second ?.nd ther, starts to drop brck'to tho zero line cis tho labclcd blood movcs out of tho right , 'chamber into the lungs. After two to four soconds, havevcr, the , .labeled blood will start ckcring thc lcft side of the heart and oncc agnin the rccording pcn will risc but not as sharpljj and not to such ' an extqnt as in thc first instance. As thc lL,bclcd blood inovcs out of the lcft side of thc honrt and out into thc bo?y, thc rccording pen will again fall back to the zcro linc. In this 'my, the pwping action of thc two sides of the heart cc,n cvcn bc individw.lly studied. Thc shape of thc curvcs produccd indicate vhctlicr ,the b&rt is" functioning normlly. If thc curves arc irrcgukr in shc.pc, ihcy my indicatc thc typ.c of heart disordcr,

4 .. -.. $his oioccdurc !its bccn carricd out in bvor'kO0 pctimts ' hiaibpstic and has nlrcnd;. prbvzd hclpful in thc diagnosis of R nm&Y of heart

, +?,c.gpditions. 2 In som cnsss, informc.tinn has bGcn obtpincd rrhich could not be arrivcd 'c.t'by othcr mms. The proccdurc subjects the patient - to'no $iiscomfort , is com2lstc'd in a fow minutcs 2nd to datc' b2.s shown no 211 c'ffccts on thc pticnts, Thc mcthod is, howcvm, still in tho .cxpcrimntal stago and has bom tricd by only a fow irpcstigatol-s. '1 . 3. ,-\ -- I Tho widcly uscd diagnostic zp-Jlication of r?-diois.otopcs is 1 -. most -4

-I c usc of radioiodina in dotcrmining thyroid glcnd conditions (Slidc 8). a. c thyroid gland takcs I+ practically all of thc iodino c..bsorbod in c body, This is hcczusc of thc glnnd's production of sn iodine containing hormonc c2.1 led thyroxinc. If the glmd is ovoractivo .. , (hypcrthyroidism),. its production of thyroxine is largo and accordingly its zbility to takc up iodino is lnrgc. Undoractivity of tho glad (hypothyroidism) Yrotluccs thc opposito offcct

Thosc conditio&' with such diffcrcnt rctcs of uptakc of iodino can oasily bc diagnosca-by using test doses of qidioiodinc. Thc rzdicxctive iodino need be zdmlnistcrcd only by mou'th"is a simplc cohpound, sodium ;r, - 'iodidc. Sincc radioiodinc gib off pdGctrnting rips 'its rate of zb- z, :1 . 6s , sorption in thc th~oi'bgknd m?.? bo dct,ermi by placing 2 Gcigcr

. A countcr on th'c ncck' otitsidc tH9' gl*.nd ?.p'd"no g it$ ~cspons~.Corn- par ison' xith rosponsc of 2 norm1 zcrson Fndicatcs thc wldoractivity or ovor2ctiv~tyof thc gl-.hd, ..

,~ ' R*.dioiodinh i's also 2ft.d in looking for offshoots (or mtastascs) of som cmccrs'of the thyroid gland. Somctipcs thcsc offshoots "rc -I hidden in thc iuhgs, "or2.in or'bond. rf th: ccils of tile cmccr offshoot ' itill hr.vc: thc ability to makc-tQ'rYoxini thoy vi11 tc.kc up radioiodinc. Thc offShoots 'mAy then bo loctrtod n Gcigcr countcr .> &ith' ,. I .*

...... , 1.. ._". , . .'. . ~. I. ,. , ,I ' ' I: .. Radioiodine has rcccntly bcon uscd for locating brain tumors. (Slidc 9). It has boon known that a dyc callcd fluorosccin is scloctivcly absdrbcd by tumor tissuc of thc brain. Sinco tHc dyo is fluorcsccnt it hes bccn uscd.to a ccrtafn cxtcnt to aid tho bsurgcon in locating tho tumor rmss during surgcry. !l%c. fluorosooncc tcchniquo is, hmomr, limitcd bcaausc it oan only bc uscd aftcr an incision through tho skull, Mpra mccntly radioactivc iodinc has bccn incorporated into a similar dyo, diiodofluorcscbin, which iq, also absorbcd by tumor tissuc of' tho brain, Mow, liowcvcr, singo tho radiatiozgimn off by rzdioiodine ayo pcnctrating oncugh to cam thropgh tho skull, thc dizgnosis docs not roqu*c an inoisicn. &bput two to four hours after thc rzdioactivc dyc has bccn injcctcd into nn artory lcading to thc brain, ?. ozrcful survey is mdc of' thc p-ticntts hoad with 3 Gcigcr. countcr.' Thc surgoon thcn mzkcs his incision to rcmovc thc tumor .a% tho point vharo hc fi.nds.th highcst radiation roading.

Rzdiocctivu phosphorus has also-baon used as an aid in loonting

tumors. For cxCZmplc, raqiophvsphoms is absorbcd mop. rapidly by thc I brain tumor than by thc nom1 brain. RadiophoSphorus.,c.a~~~hmmvcr bo dctcntcd through thc skull because its radiations, grcr not pcnctrating' cnough, It is honcc limitcd to usc during surgcry. This is valuable ncvcrthcloss for dctcrmining thc cxact cxtcnt of tho.tumor mss, espcoially of a dccp-qcatod tumor, boca&c cthcr mothods usually giw only .the tumor's gcnoral location. Aftcr tho surgcon has mdc an incision hc can 2robc around with a tiny spcoially built Goigor cowtor __ ,- and dctcrminc tho cxact location and oxtcnt of a tumor bolow tho sur- , . facc of tho brain. If fut'urc trials pruvc as suocossful as prcliminW$ rcsults indicato, this tcchniquo my bocoipc vbry valurn+blo bocnuso it is quit0 difficult to toll thc difforcnco batwocn nom1 tissue and tumor. tissuc during brain surgcry,

-.(

Thcsc zrc CXCILIP~CS of some of the more well known diagmstia appli-. I catipns of radioisotopes, Future ejc.tens5on of the use of radioactifity in diagnosing disease will depend on the progress of finding .compoudS . which can be labeled Grid which yilL.selectively go to certai

and organs of the bddy. The use of. m.dioiodine-tagged diiodofluoresceh , j : in the above illustratiqn ,is pn example of this. Diagnostic tests my also be developed which depend on the my certain labeled compounds are broken up in the body and the manner in which th r break down products - are eliminated. sych s s ,are only now begin ngl. but it is safe to say that in timet Iaad'to impof-thnt rou%in.e .tests for a 1 I number of .body i*a nd disease8 .'

..I *' ... .. I I * '1

hdioisotbpes ' d, in larger dos~=# hundreds to thousands of. time3 han-.tzhe harmless tracer dqses -,to deliver. , '; radiation to diseased tissue.. The greatest ne6d. for, troatmnt of this

kind is in controlling cnnccr and allied diseases. ' Surgery is often . not suitablo becauso it is impossiblc to gct b or romova all of th discasod tissuc. Ncithsr x-ray nor rcdim' trcatmm$ ,iB al-mys satis- fp-otcry bccausc thcy hkvc to be usod'from,outsido tho hdy and it is difficult to dircct their radi-,tions to a lcCalizcd arca. For tho S~PD ' t, roa8on radioisotopo treatment is not sati.sfactopy in, most casos. Thcre arc, hmoycr, a fcw notablp. oxcoptions; - 4-

I1050011 Possibly the s ixplcst illustrztion of r:ldioisotopc trc-tmnt A-es use af locaP applications of radiocob&% I7lide 10). \.'hen cobalt is made radioactiue, its radiatioas zre very sirnilnr to those of rsdium, in fact, if;can be used a3 a therapeutic tool in the saxe waJr. If the mfignan:: growth to he irradiated is on %n exterflal or easib accessible part of the body, either radio:.ctive cobalt or radium mjr be used->todeliver tissue-killing radiation. 9iadioective cobalt is however, much cheaper 2nd in sow cages more ?dvant?.geouS to use. It can be mchined into my desired shape or size bcfore being.mde radionctive and used in more flexible mys thrm radium. This applic3tion is however based entirelj upon mech?.nicnI. plncemnt of the rldioisotope 2s in rzdiwntreztmcnt, and therefore mkes no uniquo ?.pplication of thc properties of the mn-m.de radioisotopes.

The next illustrr.tion (Slide 11) shows how radioactive gold is being used to treat c:.ncOps .situated near the body surfc.co. The rxlio- gold is put into a specizl colloid (finc metallic particles s-wpcndGd in solution) . The colloidal gold is ixjcctcd vhif ormly throUZhOtrt- the cancer mass so as-to bombard nll the cancer cells with.rzdieCion. . Rzdiogold administcrad in this tray doos not entor into Jily of the body proccsscs 5ut stays localized in the arca into which injcctcd. EIcrc qain, the plncomnt of the radioisotope is cntfroly. mechc.niGz.~.' There is littlc danger from too much rndintion being doliverod.t6,Wm> body bcmusc rzdiomtiE gold h?.s 2 half-lifc ol" lcss than thrcc. dciys and thus drcs am.y rcpidly. kdmnt3gcs of this typc of trcctmnt ar0 that thc sitc of irradiation ccln bo locc:lizcd, thd fadioisot.opc can be easily zdministered and there are no seeds or needles to extract when the .trertrnent has been cornpleted. This type of treatment is, however,c:still in the exparirnezltcll stnge . A more represerrtctive illustration of the unique cipplication that czn ba made of mn-mad€ radioisotopes is the use of radionctive.phos9 phorus in treating polycyttiemin and chronic leukemi-a (Slide 12) Foly- cythemia is a condition of overproduction of red blood cells whereas letkernin is an overproduction of white blood cells. 2adioactlvo phosphorus is useful ir. treating these Slood dise*.ses became to a limited degree it is selectively Rbsgrbed by the 5ons :m.rrow where the owrproductton of blood cells is tpking plnce. The radiophos:ihorus may be given to the pztient by mouth in s'imp1e:sodium phos?hpte solution. Thc radiations given off by the isotd?w ".rel n&. very pcnotrating; thm the tissuas in lvshich the radiophoqphorus lacnlizos obtain the most rcdiztion. Exkonded long rango da;mge to the bone marrow is prcvcnted bccmse radiophosphorus hss L hnlf7lif: of only 14 days, yct tho irradiation is extended sufficicntIj- long to inhibit: blood cell production. This troatmnt has been cstablishcd by maby ' Fhysioizns cs tho trcLtncnt of choice for Folycythcnia. It hrbs also boon uscd with considcrzblc succcss in trc?.ting ohrmic lcukclLia but has not yovod succcssful in trcating acute lcukcmirt.

Corhin disordcrs of thc thyroid gland nrd :cs~cci~llysuited to rmiioisotops trcztncnt. This is trua bccnusc LS pointcd. out ca-licr the thyroid gland 1123 a mrticularly lcccn -.pnctit,: for iodinc. Xcrc

I105005 ?NC 21-c using tho chcmica1, behavim of ;the radiaisotope, rather th3n

mechanical placement, to achieve the desired bmlizatian. I Eladio- iodine is used for trentmnt in the Sam my it is used to dingnme thyroid! disorders except that several hundred times as much isotbpe is given to the patient (Slide 13). Of: course this kind of trcatnmnt is not started until a tracer dose of iodine bs-first been used to . dlagnse the trouble and to determine that a lclrgc dose will ben-ofit tho pnticnt.

' Radioiodine hss, for instance, becn found to provide a siqle, cffcctivu and apparently safe mothod for treating pzticnts with hjrpCr- thyroidism, fibst Cases of. hypcrthyroidism arc controlled in two to four rionths by one or two treatments. Certain types of goitcrs disappear af'tcr trcatmnt whcroas other typcs only becom smllcr. Radioiodinc is also uscd in treating ccrtain kinds of thyroid eslncor and its .offshoots. Some cancors of tho thyroid :land do not ta!a Up sufficiont radioiodine for successful treatment. liadioiodinc has , however, Drovod uscful in controlling sclcctcd C~SCSof thyroid cancer It should be noted that treatment with radioiodino or any othcr radioisotope has not yroducod EI "pcrmncnt curc" of cmccr of thc thyroid gknd or of any othor body organ, Trcatmnt consists of attempting. to control thc discasc and to prolong thc uscful lifc of thc patient,' In this, radiois otopcs have somctimcs bccn succcssf'ul.

Hcrc again wc havo sccn only somo of thc more wc11 laown *;Qys in which radioactivity is bcing uscd to trcat di80asc1 Thc futurc appli- catiosl of radioisotopcs as thorapoutic agonts will dcpond on gctting the radioisotope to a specific. organ or tissue, a gnal also sought for diagnostic uses of radioisotopes. Here, however, the problem is even more difficult because the amount of radioactivity required is much greater. Therefore, selective uptake of the isotope or isotope- containing compound by a specific tissue or organ must be much greater - probably ten to one hundred times as great as is nooessary for diagnosis, or several hundred to several thousand times as great an uptake in the diseased tissue as in othor tissues. Cancer is probably the diseasc which best lends itself to radioisotope trsatmnt but to datc compounds have not been found for which cancer colls hnvc EC very selockivc appetite. There are hundreds of thousands of organic compounds whibh can bc tried, conscqucntly there is al-ways a possibility of uncxFcctod sucoess, though tho ro-d may be long and unccrtain. In any case, firthor advantagcous ways of controlling ccrtain types of cnnccr will be dovaloped by using thc uniquc chzmical and.biochomior1 mcans of ?lab- radiation which ara possiblo with radioisotopcs and corrpounds containing thcm.

Thus fir TE havc dvrollod cntircly on ways in which radioisotoys hnvo bccn put to work in trying to improvc our hcalth and to szvc us from discae. This cm?hnsis is nnturzl bccausc tho protcction nnd improvcmnt of our hcalth is a nnttcr of such pcrsbnal and immcdiatc intcrcst to US.

2. I - 16-

110500b s ,.

'' Thc biggcr Froblcm in thc world today, howcvcr, is in saving people from wnt and hupger. For is sureljr cs we 1enE;then n.an's life span and free %'iim from disesse, we hsve more ?eoFle to feed, to clothe "nd t,o house. This means. that 2s. wc, increase the world's heclth we must zlyo find ways to incrope the r.sorld's productivity..

The most essential of ail the world's 2roducts.is food. Food productivity, of' course, is dependent on soil fertility and on agri- cultural'mthods. The grezter the productivity, the faster the SOfl becomes depleted of sol= of the food and nutrition required by plants. Also, rimy fzrning lands throughout the irorld hzvc long been oven-rorked :Ind are &lre:.dy depleted. ReTlenishment of soils with plant foods - . that is, with fertilizers - is hence 3 rilcljor nroblem in meeting the world's needs . Rndioisotopes hzve become an extremely useful tool in studying the efficient use of fertilizers, One of the very imyortant groups known as 2hosph .te fertilizers can readily be studied with radio- ' ' phosihorus. (Slide 14;. Here >.gain a radioisotope providas a my of following a certcin batch of atoms. The radioactive phosphorus is incarpor'ated in %!IC. fertilizer which is Gdded to the soil being studied. Later, rzilo-..ctivity 2,nnlyses 0.f thc plzd shelf t.rh2.t +rts of the pbht have takh up the'radioactive c.+toms and honoe ths f'e$rti- lizer. Ch&&cal analjrsss of the p1mt indiccte the total ?mount4ef phosphorus coming froE tho fertilizer plus tint cordng from tho ordi- nary phosphorus previously proscnt in the soil. .. From such studies, investigltors can determine not only how much phosphorus is taken up by o plant adwhere it oame'from but also the efficicnoy of the fortilizcr, the best type of fertilizer to use and' the best plncc to locate the fertilizer wi-kh refcrcnco to the location Of thc plnnt. Tcsts such as those have been c2,rricd out very cxtcnsivcly Et 'the U.S. Dcpzrtmnt of Agriculture in Bcltsvillc, Nai-ylmd and at qy-icultural cxpcrimont stc.tians located in 0-rcr n dozcri statcs. A nurnbcr of difforcnt crops, such 2.5 pot~tocs,corn,, bcclns nnd cotton, 2nd way different typcs of soil b.vc bccn studicd, ?Taro cfPicicnt ' mys of using fertilizers aro 'ccing found for cach type of crop ?nd dcplotcd so'il.

.. ' In bhe next i1lus"crztion :(Slid2 15) wc scc .thc spplic-tion' of 3 rzdiolsotopc to thz study of livcstock nutrition. This conocrns ' dcfiokcncics of dict. It hqs bcon found th?.t vcry snz-11 amounts of ccrtah mtallic alcmcnts such CIS cobzlt, coppcr an? zinc, arc ncccssary to animal dict. CQbalt, for inst-nco, is z nocczsary c1e:cnt. iii thc cow's-.diet. At present for instanco, areas seriously deficient in cobalt and therefore sites of sei-ious livestock malnutrition have been reported in Florida, Michigaq, l:assachusetCs, .\isconsin, Yew

Halnpshire and Mor€h Carolina as well as in New Zealand, Australia, ' Neil South -Tales, Africa, the United Kingdom and Cancda. ':'hen cattle are fed on forage containing less than 4 parts of cobalt in one hundred million, they lose thoir appetites and literally starve to death although surrounded by a luxuriant growth of pasture, On the - 17-

I105001 J I. i \ other hand; hors'eo placed in tHe 'same 'past& r'erain in excellent health. The problem dtil 'recen%ly has been' comii'doted by the fact that the amount of cobalt in the blood and tissues of the animal is s3 small that chemical analysis is inadequate to diagnose the condition. Reoently radioactive cobalt has been used in investigating thjs problem. The radioisotone technique is sensitive and reliable at these snnll concentrat ions. It also allows 'the fatc ' of cobalt in the physiological processes to be 'followed, Cobalt ays'poars to bc essential in the baotkrial processes of digestion which go on in the rumn of the cow (also of shecp). All the traccr rosults arc not Yet" undcYstandable; it 'beine; found thct thc problcm is mor'c complex th4n had originally becn supposcd. 1, Another radioisotopc zpplication - an application entirely academic in natW at thc prcsent time, although it has possibilities of Sur- p2-ssing in significance all other radToisotopc invcstigzti6ns - is the. study of nhotosynthcsis. photosynthcsis is TTaturo'a sccrot proccss ' for taking wctcr and carbon dioxido with the aid of sunlight' and making food - food not' only for the plmts 'thcmsclvcs but for 211 lifo on . carth. Indccd, it is thc procoss which not only supplics thc wrld with food but it is also rcsponsiblc for tho cncrgy in all thc fucls,' Such , as coal and oil, which wcrc laid down in thc carth in agcs prist, ThC only 'Dxception to this am atom4c cncrgy fucls - thc fissiomblc ' m?-terials. Thc cnorgy of sunlight itself, howcvcr, has its origin . initially 2s atomic cncrgy - as cncrgy rolcasod in atom;c proccssos in thc sun:

Rcccntly, radioaotivc carbon has bccn cnliskd to zid scicncc in trying to: lcclrn thc sccrcts of photosynthcsis (Slide- 16) . Chemic21 ' studics- ham shown that thc plant combincs vator carbon dioxido to .form sugars and sh5rches but the details of how the synthesis takes place &re still unknown. By tagging with carbon 14 the carbon' dioxide fed .to plants and studying intermediate products formed during this complicated sjnthesis it is hoped that we can achikve'a detailed under- standing of the photosynthesis process. I. . To do this, investigators have allowed photosynthesis to take place with labeled carbon dioxide, for definite periods 13f time in vsricus plants - a favorite, subject being simple water plants, called algae. By interrupting the pr'ocess'at various s'tages it is possible to identify certain organic struct'yes in the plant simpler than the mbre"complex food molecules', suck sugar .,, RZaJoacCivity cna lys es of the various products of thc plant disclose whi'c homical corqounds contain the radioactive C on atoms.. at tho aria To d+te, investigatois have Soen successfil in finding a number of the Yreliminary or kntcrmcdiutc products containing r=dioactivc carbon. Indeed,-it has bcm found that cvcn in Icss.th0n fivc scconds thc photosynthcs is procoss incorporatcs the radioactivc carbon atoms into somo complcx intcrmcdintcs, md in 69 to 79 s'cconds thc i carbon atoms. have bum incorpor::tcd into complxcctod sug::r molccul,*s!

Such infomiation could not b, dcterfiillcd without the aid of trzccr isotoms. Again, hcro is cvidcncc of thc unbaliGmbly rapid and corplm Droccs';dz or biologic21 syst\ ris - ~vznin such n~parcntl.~simlt singlc cr,lls ns lgnc. Furthcrmorc, it indicclLzs strikingly hovi i?')tnc s 2rc inmlu-tblc for t-ckling t!?c ;undnmnt 11. srcrcts of YaturL..,

Sut t!ic w011d's staild?i-d qf' livinc is dcp;.ndcr,t or: morc thyn food productivity -.Ion . To ir,crca,cG this stc.nd?.rd of living 'ru xust also irnprovc thc productivity of othci :iscf:il mtZri?ls -.rd goods. 7erc is whcrc industry cntLrs t!ic ?icturc. i::dccd, continu,:lly zdv2ncirig st?..-,d;r.ds of living caonly bc. Tchidved by thc incrzzsc of both industri- i - nd ?...gricultural yroduct ivity.

.?l.dioisoto?cs hcvz not bccn uscd P.S cxtcnsivcljr in h6uskr:?.l rcsoarch ::s in othcr typos 3f rcscarch. Ti;ilc docs not Fcrmit US to go into thz rz-sons hcrc othcr thnn to say that at thc bzginr,ing of thc ?rogxinl vrhcn r::6dioisotopc ?roductioii KLS s olm:vrh?,t lirnitcd, pri?rity vxi givsr! to Ificdic?.l rcsc:l.rch invcstig2.tions

DuriQg G!IC 1-st par, horrsvcr, isotoFe production %s 3ccn 2roG-t cnough to mect ;hc dcimnds of invcstigntors in :ill fLclls I€ stud-- nnd industri- 1 iavsstig-tors hsvc. joincd thosc in 3thGr ficlds jn usir.g tPcsz v-.lur.bio tc3,ls.

q* Onc intcrzsting study 'ir?s bccr, in thc fi;Id of nct'llurgy 2nd is conccrnvd xith !?aintoFs movc cbout in solid nctnl. Fct-llurgists have long thoclght thrbt the itoms cvdn in solid mct-Ll tcnd to movc iround or diffusc but thc:c w:lsn.rt p.njr -n;r oi' :.ccur?tcl;r mcnsuring this Thc ncxt illustr?.tion <,5lidc 17) shcws the wzy tr:-.ccrs qrovcd th?t >+tons -do diffusc ir, solid mtal md prorridcd ?.ccurclt, drLt?. on tlic dcgrcc of diffusim. h radio?ctivc coppcr block -.nd ;?. non-rndio-ctivc ccppcr block zrer'o CI~EI?;~togcthcr and b<--.kcdnt a snccificd t\;mpcr?.turc for scvcrr.l hours. Thc tr:o blocks xore bnkcd bccsusc accorCinC to khcory atom shoulc! novc :.roLud more rc-.iily -3 thc t .rnpcrrittlr3s ,-.re incrcsscd, cvcn though such moxmont i;roulc? still bc cllmost infinitcsir.31. Tha blocks varc coolcd Tnd ?&gainf,i...k~n Apart. Surc cnough rr

Onc limitation to .the usc of r::.dioisotopcs in tcstiiig inLwtri31 products is the possibility th2.t som of thc radion.ctivity vrili bc lcft in thc finishcd mrkct product. This might bc dangerous to thc Consumr as wll 2s to o'ihcr p;opls who !inndl2 thc ?rotiuct bcfor- it gcts to th, consumcr. For this i-%*-.sop distribution of radioisotopcs %forusc in indua try h2s bccn +pririnrily linitcd to 1-tboratory sc-ilc rcscarch problcms. .(- - 17-

I105009 2nc r?.dioisotopc rrsc-.rch invcstigntion vb.ich my p2.y off dividcnds Ivrithin th?; nzxt i'c-ir ymrs is th,, s tud.7 of ircar .ani lubricntion. Thc ncxt illustr?.tion (;lidc ,lo) shows how onc conipmjr is s tudyj~ng:'Ic?r in cngincs. A piston rinc is s-nt to Oak Rid.gc, ,nndc radioactivc in tho pilo 2nd thcn rctur.ncd for plwcmnt in ?.n cnginc. Thc notor with its rndio2.ctivc piston rjng is thcn run. As thc: ring :7cnrs, 3omc of ths rndio:.ctivc atom -irill gct into thc oil. Pcriodic s?mrlinG r?.dionctivity anr.lys is of t!ic oil lubricant will show just ho:i{ mch thc ring is maring amy by friction. Also cftzr thc run has bccn com?lctcd n photogr?.phic film my bc plxcd against thc ins idc surfr.cc of thc cyclindcr wall. R-.dio,q.ctivity which h?.s >con transfcrrcd to thc cylindcr 1~11-:;ill exposc thc ?hotogrc?hfc ?l?tc 2.26 shw.r thc rcgions of CrcntGst -:Jc?.r.

m L~CSCstudi-s crn -Lccur-.tcly detcrmins onc-millionth of .n oU1idc: of mctyl tr-nsfcrrcd from thc ring to tnc oil. Tcsts th3-t ~rcviously rcquirid sever-1 wccks ca:~nwr bc donc with morc nccurccy in - few hours to .I. fcv days. Such stvdics should cvcntually lcad to thc ?reduction of bctter lubricants 2.5 ~~11as to bcttcr dcsign of dicscl, :-utomobilc Tnd ?irpl-.nc cnkincs.

About tlic only way in ;qrhich r?.dioisotoFcs hr.vc bccn uscd ir, controlling industrial production thus f?r hns bccn in thc gauging of thickncss. Thc r-.dior.ctivs thichcss gnugs (Slidc 19) dcpcnds on mcasuring thc amount of ridi2tion originating from .> r-diois otopc sourcc which will 2cnctr2td thc i:Ltcriz.l to bc Caugcd. T;), instrumont which dctccts the p.diztion is conncctcd to a r2diation mctcr which my bc dcsigncd to rcad in thiclmcss v-lucs. Of coursc, thc 2nount of r-.diF-tion passing through thc a-,tcrial is ricpcndcnt on tho thiclcncss of thc matcri-.l. The radiztion dctcctor is ablo to dctcrninc small diffcrcnccs in r?.dP?tion and thcrsforc snnll di ffcrcnccs in thichcss .

. Thc radior.ctivc thickncss gaugc is particul-rly vnluablc bcc-usc it is vcry scnsitivc to small diffcrmccs in thichcss, boccusc it givss rcproduciblc rosults bcccusc no contnct involving thc possibility of tcnring or mcrking is ndc? with zhc slicct bcing mcasurLd 2nd bccausc a grcat rangc of thickness-s nn.y LIC ncasurcd by mtrcly changing thc rydioisotopc to givc the dcsircd typc of radiation. This thickncss gaugc my rLlso bc uscd to mcasurc a continunlly moving shcct of mtcrial. lis -n zddcd fczturc, t'nough it is not in operation 2s yet, thc gaugc my also be uscd to control ths rollers to rcgulntc thc thickncss of thc shcct material during qroduction.

Thcsc thrcc cxamplcs a-c tmical of somc of tiic IN~YS in which . radioisotopos h?&vc bccn uscd in thc applicd phases of industrial rcscarch. They arc not indicAtivc, homvcr, of somc of thz lcss well- known npplications in long-rsngc industrial rcscarch prob1c.s or f.rc thcy indicrLtivc of thc mny potcntialitics of r?.dioisotopcs in industrial rGsmrch.

R:Ldioisotopcs ?r2, for imtancc,' cvcn now bcing us3d in other investigations covcring such a scopc of topics 2s wlccnization, polymerization, corrosion, cat-lys is , wc11 logging, organic synthcsis,

I JOSOIO flotation, ctc. In rcccnt months mny mdrc i-rrdustri: 1 applicntions have bccn suggcst~dfor thcsu c~luabloznd vcrsc.tSrlc rcsw.rch tools Indccd, thcrc is cvcry rCQ8On to bclicvo that within thc ncxt foW years with additional trained pcrsonncl ?nd with 7.n additionr'.l. number of industrial consulting l?.bor=torics offcrigg scrviccs to prospcctiTc industrial uscrs, industry ;vi11 find 2s mny 2nd morc uses for radioisotopes as' have thc ficlds of biology. 2nd mdicinc. ' All wc havc bccn cblo to do in thc time nmihblc hcrc is to present just a fcw illustrctions of the way in which isotopcs Crc bcing mod. Isotopcs arc bcing uscd in morc than a thousand individual invcstigations by ovcr 500 groups in somc 250 institutions throughout 39 stntcs, the District of Columbia and Hcvmii. Thc studics arc in 311 fields of labomtory scicncc frorh ngronomy to zoology, as Val1 xi in agriculturc, mcdicinc nnd industry.

R?.dioisotopcs ?.rc ccrtninly not unknoim tools to invcs tigators in IJCW York City and Xcvr York Stzts. Indccd, Bcw Ycrrk State lcads 211 tirc other 39 rccipicnt stxtcs, the District of Columbia nlid IiaT;Eii in thc numbcr of radioisotopc shipments rcccivcd c.nd in thc numbcr of institutions us ing' radiois otopcs . Its 774 shipmcnts surpass. by corc than 50 the noarost contcndcr, ?iassachusctts, and cccount for about 14 percent of the 5,550 shipments rndc to dnt:. Thc state's 35 using institutions surpass by 10 thc ncarcst contcndcr in this rcgard, C-lifornia. Iiost of tho icstitutions using radioisotopes in Ncw York StLtc arc locatcd in Ncw York city, in fact, 27 of thc 35 institutions.

T~cold political ,.. dzge, "SO gocs Ncv~York, so goos thc coui:%ry" is most nppropri?tc in discussing thc radioisotopc distribution yogram.

I would now likc to mkc -, fcw sidc rcmrks pcrtincnt to thc tcaching of atomic cncrgy and of scicncc in gcncral.

You who aro tcschcrs of soicnc!c should mkc cle9.r. in Ocaching all thc wondcrful things th2t scicncc has discovcrcd and roxFlishcd, that scicncc is not an cnd in itself. Scicncc is not sor.cthing to bc worshipcd. It docs not proirido all thc answers. Thosc mth 2 littlc knowlcdgc of scicncc i- young and old alike --.my bccom Cocky about thc powcr of scicncc. But'thc initiatcd pcrson, thc truc scientist, is humble. Hc bows that Scicncc tclls us -:thct and how, but not 1-rhy. 3c kno~~rsthat tho morc hc lcarns, thc more hc discovcrs thcrc is yct to

lcarn. L'

I Thc extension of' knowl43dgc into the 'vast rcgibns' of ignorance' is likc tho shining of light into complctc darkncss. Thz light is alWyS surrounded by a p'criphcry of darkness. If i'lc start rtth ,'t cnndlclight, wc can only scc a short distziicc and 1:rc zrc avarc of an cnvclTpc of darkness quite closc at hand. If vrc cxtcnd our sourcc of light to 3

7 powcrful searchlight, we will see vcry inuch morc. -A yct, 7.t thc Smm tim, WC will notioc that the sizc of c)ur pcriphcry of darknoss ha6 also cxpandod greatly. So it gocs with knowledgo, as our horizons CX- pad, SO do thc pcriphcrics of dnrkncss . Tho boundaries of knovrlcdgc arc inf initc . -21-

I10501 I f 3~ hzvc hccnr tp2king hcro r bout rr diois 7k~pcs.'1s iilportxnt bcncf its af atomic cnorgy. Otpci bcncfits of imcnsurnblc.%mluc.will ccrtainly corn from thp ckvclopmcnt of uscful atonic power 3116 from rcscarch in atomic sci.cncc.! . , .. ,I --rC must rcnii hovwvcr that -wc arc 1iEki1i~an ,infcrrcnc.c. Libat 'dc infcr is thnt sincc ?tonic cncrgy dcvclopmcnts cnd npplications c3n bc uscd to nnk; ?: ~plchinlthicr, inercasc their pr?ductivity, adrclicvc thcir intcrial \:3nts, pcoplc will livc bcttcr livcs an9 be hnpgicr.

Vc should bc cl(aar that through thcsc bcncfits of scicncc m a-c rcmying 3nly thc most obvious causos Jf dissatisfaction and u.nhrTL?pincss, thzt is, tk ncitcrial mcs. Far groatir problcss of humn Frogrcss ?.rc fDund in thc sociological and political aspccts qf lcarniag to livc togcthcr. Thc hzsis f?r solution of thcsc yroblcm lies ,largclY in nornl -md spirituAl rclitionships.

In .'mcrica VJC 2.lrcady hlvc by far thc rrorldls highcst rn?.b2ri91 standard of living. Vc hzvc onc of thc hnlthicst pcop.lcs in thc njorld. Vc havc, thc most litcrato and cduc2tcd pcoplc on thc nvcragc: in the world. Our- g~v~rnmciitis one of thc nost truly rcprcsCntztivc of its p"plc. All this has stcmcd fron our bclicf in thc integrity of thc individual, fron faith in b'oth thc montzlity 2nd norality of thc individual . 'Jc bcliLvc that. cnch indiyidml counts, that czch individual's - productivity counts - -zhcthcr it is ill growing "qat3 , peas, bc9-r.s -nd barley" - xhcthcr in aking c:.rs, rcfrigcrators or radios - xhcthcr in tcacliing Df' facts, truths 2nd rc2son - vhcthcr in thc r,mnagcmnt 2f good gmcm.mcnt - Dr irhcthcr in crcnting art, idccs 3r new knoTllcdT,c.

Atcmic energy hc.s come to us as a hew force which.can enhance man's productivity 2nd knowledge. It can only be successful 2s CI benefit to humanity if it cm be used in. productive rather thzn destructive ways. This 311 depends ,iapon,the recsoning c.nd the moral and spiritual forces *#hich c:n be brhght to benr. on the use of. this new physical force. "hi:, in ,$urn, denends, on .the educnticn that shapes the minds of mn, npt j'ust in: the thre,e R'g, reading, 'riting, and 'rithmetic, but in two, other Rfs' reaso;ing.and relationships - that is, in unbiased reasoning.and human relationships.

- ., , .- I .I . ,. b 2 .I The greatest competition in'the world today is for the minds of men. It is the job of educztion to produce minds that have the power of unbiased reasoning bi+sed on free thin!ciGg;. ability tp sep".rato fzcts from falsehoods --also' minds -f;hzt can.uhderst$nd and palance hmn relationships - the qobial and moral relationshjps of m2n tg man. i . .* In this training of minds, 2.11 of our mdia of educc.tiQn, -- the schools, how , church, prqss, ,radio, civic and frat$tnql organizations , etc.-- must recognize their,,part. You, .hov?e~~yr,as toachers play 2, key role. blot only do you'bave ~1 pionouqc;ed'and l?sting offect in 4

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1105012 You of course toc.ch that corrcct re,).;oning is bxed first arid forexost on truo f-cts . In tcTching humnn rcl:-.tionships you point out that all our rclationships witli e?.cli othcr ?.rs bzscd on OUT SCIISC of brsic v-lues -- in fnct, on our scnse If ?ui-~oscir, life.

In :i.ppro:Lching tiic problcrx of 3toir.j.c cnergy, or Tny othcr probkrls f-cine us TVro ngF.in nced thesc two gunrdians of our decisions -- facts -nd 2- sense of purpose. Thcsc zrc: thc r?rarp c..nd woof of our living.

All the f3ct3 of ?.tomic cncrgy in our possession, hoircvcr, ?.re not presently frccly ?.vnilnble. This i3 r,ot cntircly in l:ee:,ing .;rith our Ancriczn ~nyof doing things. Cut this exception is not of our omchoosing. It is dict?.tcd by the 'Ircscnt -;iorld situation.

Yct more frcts arc avail:.blo on ntomic encrgy than is ordimrily sup?oscd. Indccd, most of tnc facts of bxic atomic scicnco -nd its non-militnry 3pplic-.tions arc opcfily zvail-blc . Dissefmination of thcsc fncts irould do much to rcpkcc thc misinformtion ?.bout ;.tomic cncrgy xhich is prcmlcnt today. Unfortun?.tzly, thc early cmp!i?s is on thc dcstructivc sidc of atomic cncrgy has tcndcd to ovorshadm its constructivc sidc -- its brighter sidc. This afternoon I havc tricd to givc you sorc facts, although only skctchy, on thc brightcr sido. I hopc you vi11 pass thcsc on.

'.lien it concs to instilling v-.lucs znd a scnsc of purposc of living, this is not ?riw.riljr thc rcsponsibility of tcachcrs. Thc honc and thc church nrc supposcd to SCC to this. Ncvcrthclcss, tcnchcrs in prcscnting Tr-cts and reasons can indicatc vcllucs and purposc.

Atomic cncrgy is: 2. grczt ncii forcc uhich cm bring us 2. bcttcr matcrial vcorld -- 2 bcttcr world on which to basc bcttcr social and moral living. Also it can strcngthcn our scnse of valucs and purposc. And, armcd with a faith that wc wcrc not ?ut hcrc to blow cach othcr to bits, at0rni.c ciiorgy ccn add substzntially to our moral forcc in bring ing .?.bout pczcc and human bcttormnt .

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