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NONTHLY STATUS AND PROGRESS NXRT Division of Biology and Nedicine MONTH OF DECEMBER 1953 Rese arch kctivi ties hb oratory has extended the somatic mutation program which Was initi - ated i n Deceinber 1952 t o test the feasibility of producing useful mt at ions in plazqts by means of ionizing radiations. The major agricultural experiment stations in the .east are taking part in this research work. The main emphasis inthe program is on the production of somatic mutations i n plants, slwubs, and trees which are normally propagated asemally; The experiment stations select the.mter i al be treated, and after irradiation at Brookhaven the rnaterial.is screened for usefulness at the origin a tiw station. Most of the mate-' rial in this program i s grown inthe gamm field, where carenil observations are made of abnormalities. field used for these experiments has been increased from 260 caries t o 2,200 curies. I n addition, the location of the sow ce in the field has been changed and the field enlarged. indication of tine usefulness of the field in t'ne biology program, and wch nunhers of plants are being used t h a t a posft'ive answer t0 the applicability of radiation as a tool in plant breeding should be avzilab7,e in a few years. The increase i n size is'an Also a t Brookhaven, use is being made of t h e thermal neutron tinerndl neutrons are more effective in producing.mutations fora given aqount of damage than other forms of radiation. clear from other studies that thermal neutrons produce radiation damage in biological material by quite a different mechanism Chan do X-rays . and are thus providing another effective research tool. A n example of recent work with neutrons has l e d t o some findings on inducing disease resistance i n plants, Rust diseases bring annual losses of millions of cro? (after corn). Investigators at Brookhaven d o s e d several hundred oat seeds of the Ibhawk varietq t other nd neutrons. ,Wter the first. crops were harvested, seeds were planted in the s mer of 1953 and a . ~ ; second-generat5on group grom. Artificial inoc-dations of oat stern rust -f~%us (Race 7k),to which the Mohaxk strain is particularly susceptible r were given t o these plants. The rust fungus spread uni for dy throughout -t he oats nursery, affect in e all but a few plants. I n those wliere infec - r n %!.On ha.l taken place, it was demonstrated t'nat t h e plants had a resj.s& 0 I t2h3 and planted i n t h e fdl. Resultant plants weye inoCJ1atkd .facility for mitation production i n plaqts; it has been shown that It is also becoming' anCd which pre-rented any danage.' I n tine few not infected, seeds were
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the rust disease but continued t o show resistance against it. far as is knom, the new strains have the desirable characteristics of the origin d Nohawk variety, including high yield. cqerimenix will. be continued t o 'determine applicability to other vai e ties ,and crops. cip1.e which permits t h e rrieaswement of the mounl; of energy zbsoFhed ky tissile frm ionizing radiations. pre tz tion of ra diz tion expeqiments require that the raciiat.iort flux and its f%osetr(absorption) be known i n ergs/cm2 and ergs/gram, respectively, the actual calibration measurements are usually ~ 2de with ionization chambers rather \ than directly by a calorimetric methoci. This procedure has been customary since ionization measurements have I . teen convenient, and reproducibl.e, whereas the direct calorimetric measurement has appeared difficult. The necessary cornersion of the ionization measurement into absolute units i s simplified with the assvnlpticn of the Dragg-Gray relation but is not &ways simple o r certain. Ey the calori.metr5.c 'method which Sloan Ketteririg Institute has developed recently, it is now pssible to quantitatively dete the relation between ionization and absorbed energy as a function of atonic nunher of: absorber a d energy of X-ray to exd m any lintita-. %FCP.S of the Gragg-Gray- relation that might exist, Scientists working on this project suggest that this cScr5.ketric method of f1.u determination be adopted as the fundamental calibration of the output of the roentgen-rzy generatcrs, particularly for generators Radiogermartiwn In hala tic n Studies. [II'NCLASSIFDD) The usefulness cf radicis o topic rnzberials i n evaluation of in d astrid hazards is exem - pli fie dina recent report from the Kedical lkpartnient of Ercsokhawn : Ilaticnal Laboratory on a collaborative study with t h e U.S. Navd Eospitsl, a t St. Albas k w York. The study invol.ved the use of pil-e-zctivated gernariuir! (cell)to trace the fate o? this elenent after inhalztion of germardun dusts, such as might be met h 5 n g the production of various Rats were exposed for one hour t c atmosphere:; containing the in t weLs after exposure, lungs ard through the other organs. the rericval of the elemental germ.a.nium depends prjmar5ly on the rate a t which it becc;nieo cxicjizecl upon standing in +,he lung. No ir it ation, ? . >.ungs, liver, and kidneys vere then removed znci esmi9nr-:d at. varying permitted tracking of the elimination of. the element from theo
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gross pathological charges, or other adverse effects were noted as a result of .the cont zd of germanium with the tissues, show that this type of exposure t o germaniun does not constitute a significant industrial health hazard, such as lead, mercury, and uranium, whether radioactive o r not, tend t c be tcric and provide indus tria2 hazzrds during their haictling. Xoiqever, the toyAcity of each of these substances dicfers sonewhat m d may have several facets.A full understanding of this.prohlem requtres hod edge of the reactions of these materials with the vital materials of the cells ad the resultant upsets of functions at the A series of studies are being performed a t &he Rochester dtomic Energy Project on toxicity effects in microtorganism and organs such as the diaphragm and intestines of higher animals. XP experiments with mercury, it has been found t h a t small traces. ' inhibit the metabolism of living tissues. The inhibition was studied i n excised rzt diaphr,qn muscle i n Berms of total o q gen conswrrption * w5thin afew minutes Fn the presence of certain dilute concentrations cf mercwic chloride. However, vsing a sensitive histochemical methoc! . at that time, no mercury codd be detected inthe diaphragm muscle the respiration became progressively depressed, the mercury-sensitive rez ct ions involved i n glucose utilization zre at the cell surface and are concerned with the passage of sugm from the outside to the cell interior, The mercury-sensitive respiratory reactions, boilever, o cw rk it lli r ? the cell, ard this imposes a time lag before appearance o f the inhibition, Rad k tion .Instrurnents Progrwj Glucose utilization uas completely inhibited. Afew hours later, as the mercury appeared within the cells, Thus, it appears that ' recently completed astua - of the vk-ious film dosimeters used xithir .the AEC. This stcdy wzs divided into two parts. stuiy of t h e rznimun range, quality dependence of the dosjneters, arici second, a cross calj.bration consistint: of an evaluation of tho zbi1j.Q ' r . by 13s i s now being ansl.;-z&d by the 1nstzumen-t.s Branch, It has been suggested, in view of dif€erences reported by the
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izho worked i n Canada on the reactor cleanup, that an invitation be extended tothe Cma.di.ans to participate in a similar cross calibra- . tion stuc&. Mord has been received fron Canada that they would be hzppy to participate ' inthe stu&, and it i s eqected that this work will be coq3e ted d wing the month of January. ' Civil Cefense Xc ti vi ties revision was approved inthe.directive governing the 18.emergency radiation monitorink teases tz blis he db Februuy 1950 zt 6 Operations Offices and 12 supporting loc st ions to (1) monitor any on-site o r AEC-connected raciiological emergency o r disaster; and (2) second qi ly, ' to provide monitoring services i n event of a civil defense emergency resulting from atomic. zttack, .. 'he revision relieves the Operztions Offices administering this prograni of responsibility foz civil defense monLtorine and.restricts use cf the team t o AEC sertice, This action was taken after consul-. t ation with the Federal Citil Defense Administration .anti recognizes the geherA imprcvement; in rad5ological defense capabilities. of the various state md local * civil defense crganizztions. +,inlied, ami net? team may be estzblished a t Operations Gffices not originally included inthe progrm. (UMLASSIFEII) The Chzirman addressed t h e kihite House Conference of - . ..!*&-ors on Zecezber 14 a t the invitation of Administrator ;Peterson of t h e Federal Civil. Slefense kdministrd5cn. a d City i-;x,agers of municipalities i n excess of 75,@00 populztion attended this tvo-day conference sponsoreci by the X%ite House and havFng strong civil defense overtones.