X Ray Exposure in Oak Ridge Tennessee

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Xe are i n receipt of a letter fmn t3e Union Carbide lhc lex CoqXqT under date of LIay 9, 1957, thrcc copies of rihich we enclose, w i t h an acconpargrFnZ outline on stand-.rd methods recorcended fores that - ing neciicfi eo sure ;re?zred b;r a cormittee of the International Conmission on Iizdiation Protection. O z k Ridge llational Labaratory bas already undertaken detQzlincrtiom of the average skin dcse and gond dose received fron t - nicd. di agno s tio X-ray procedures a t eight installations. deterninltions of &the average dose f o r their personnel. Meanwfiile, prior to proceeding on Further studies of worn re Czrbide calls our attention t o the erdosed report of I W adopted as a statenent of recomnanded standard sqUng procedlres, a pmorm developed under chairmanship of I)r. Karl 2. 3 r g a of ORTlL. proposed that the IC” recomnded survay nethods be adapted t0 presurvqs on a pilot scale i n ordcr IXIevaluate sampling; methods and data selection. Carbide muld like t o apgly appropriate parts of the I C W sampllng procedures to cover i t 3 own recorda and those

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C:-JIL has persormd to successfllly perforn this task and seem m r t h - ccnstitate a fbndcental contribution of broad interest t o the Je feel that

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UNION CARBIDE NUCLEAR COMPANY POST OFFICE BOX P OAK RIDGE. TENNESSEE oak Ridge, Tennessee Your letter of Jvluary 16, 1957 regarding the above s..bject suggsted that a feasibility study of Carbide medical exposure records be underrlaken t o obtain an average X-ray exp csce dose t o the skin and gomds. I n addition, it was suggeste3 tbt a more elaborate study be undertaken involving X-ray rezorzs a t the Oak Ridge Cczzunity Hospital and that some of o w expi3rienced personnel night assist. Iaboratory personnel have determined the average skixi dosegonad dose received f r o m typical diagnostic X-rays aikfhistered a t eight differect installations. diagnostic X-ray exposures are maintained a t the four Woide facilities,a perusal of these records for the dete an average dose for our personnel could be undertakell a t any time. Because complete rzcords of We would like to call your attention toa proposalmz.5e t o the of this Laboratory. which has t o do with sacrpliing procedures necessary t o ascertain the gonad dose received by the popdation as a whole frcn ned icd hrgan was adopted by the ICRP during its meeting the first two weeks of hy this year i n Gneva, Switzerland, and shmld supercede any l e s s global proposals such as the investigatlon of the Dr. Jbrgan is Commission Leader of Task I11 The method chosen f o r the study involves a selection zt randam of a representative sample of medical men who are respocr;ible f o r administering expcsures, m d medical institutions in uhich most ofthe exposures were given. I n each case, the representative sample is t o be studied by letter questionnaire and/cr personal contact, and in str me cta will be furnished as an adj cc t to the

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The nethod reconmended for the primary survey is personal contact of the surveyor with the medical institution, either with or with - out the f’urnishing of instruments. will be conducted on a pilot scale before undertakjx? the primary survey in order t o permit a better selection of the 5ample and t o W e certain that all of the data needed i n the fin=r’ returns are collected with the required sccuracy in the most ecoromical way our intent t o include the Oak Ridge Community Hospitd in the pilot surveys, since its data are rather better than those of the zvexage medical institution around the world. Several types of presurveys In this colulection, it should be poicted cut that it is Consideration has been given i n 2reparing this plan 50 establishing a study system that has sufficient flexibility to per s it its extension t o accumulate inf’ormation on the relationship between dose fram ionizing radiation and somatic danage, as well as gezetic damage. We attzch herewith a copy of the preliminary report of ‘Z-ask 111 for the International Committee on Radiation Protection whic: gives the detailed proposal which has nuw been adopted i n order 50 solve the problems t o which your letter alludes. If you have any f’urther questions, please f e e l free call upon us. Yours very truly,

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MGI?ODS OF EST WING THE MEDICAL EXPOSURF: TO IONIZDJCI.RADIATlOIT Contributors To This Report This report was summarized by K. Z. Morgan (U.S.A.), joint c d s s i o n Task I11 leaiier, from material furnished by the following: country National Ieader Task III Leader

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This study is directed prim3sily t o a review of sampling procedures which could be applied i n a survey t o determine the average gonad dose received 3y patiezts from exposure t o medical sour ~ e sof ionizing radiation. volve the selection a t random of a representative sample of: medical institutions Fn which most of the exposure is given. tive sample m y be studied by letter questionnaire or personal contazt, and instruments m y be furnished as an adjunct of the survey. vey is personal contact o f the surveyor with the medical institut i oo either vith or without the furnishing of Instruments. pilot scale before undertaking the primary survey in oraer t o permit a better selection of the sample and t o make certain that a l l the data needed i n the fizd. returns are collected with the required accuracy i n the most economical way possibli. should be given to a system that has sufficienCv flex i bix ty to permiL its extension in order t o accumulate information on the relationship betveen dose f r e ionizing radiation and somatic damage, as well as genetic damage. - The three sampling aethods discussed inmedical men who a r e responsible for adninistering t 2 e urposxe; and (3) The method recomendp- f o r the primary surSeveral types of pre s mey s shoed be conducted on a

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This report of Task 111 is limited toa cursory review of yarious sampling procedures that might be applied i n estimating the medical exposure t o ionizing radiation. FkrticuLar attention is given t o a study of sampling methods f o r obtaining the gonad dose of-patients receiving medical exposure. However, the methods recommeaded here could be extended i n order t o make an estimate of the dose received by other organs of interest, e.g., the bone marrow and the lens of the eye. i n applying these methods t o a study of occlrpational exposure t o medical sources of radiation, .but a nmber of inodifications would be required if the survey were extended t o include a study of other types of occupational exposure, e . $ . , industrial radiography, X-ray There would be very f e w additionalprobleas I n some cases there is an overlap of this report w2th discussions of other task t h a t could be applied i n estimating the gonad dose from skin dose measurements and from bta on the type of exposure, the X-ray techniques used, and information about the charact eris tics of the patient. which is considering the problems associated with sending a questionmire t o professional This is particularly true with reference t o Task I which is reporting onmethods Also, there is considerable overlap i n the case of Task Nc., Several questions are raised which must be answered before final recommendations can be made relative to w h a t appear t o be preferred sampling methods tions are as follows: Some of these ques- - _ 1- Is it desired to determine the genetically significant dose from i o n i z i n g radiation (a) that the present population has received? (b) that children conceived today w i l l accumulate during their reproductive period if present exposure conditions continue unchanged? or that chilihen conceived today will accumulate during t h e i r reproductive period if the present trend of increasing exposure t o ionizing radiation continues unabated throughout their reproductive Ufe? 2 - Is it desired to choose the single sampling method t h a t would be most applicable t o all countries or should several methods be recammended and each be applied where 3 - Is the recammended sampling method (a) t o be used only once ina single world-wide survey to obtain the presently existing, genetically sigaificant, av6rage gonad dose f o r each intermarrying group in the papulation?

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(b) t o be applied over a continuing period i n order t o keep track of the (c) t o be applied continuously i n order t o control individual qo sure s genetically significant group exposures? o r in addition t o serving as a means of collecting group data of genetic sign if lcance ?

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Although on first thought one might be tempted t o recommend dF-rect measurement and recording of the exposure t o ionizing radiation received by each and every person in the pcpulation, a study of the stupendous problems involved and high costs leads one very qcLckly t o consider seriously the more immediat ely possible and practical methods of samplk g ‘;he exposure received by a small segnent of the population. of placing a dosimeter on every person i n the population would be: The principal advantages (1) The dosimeter, if properly used, provides information useful in estimating the accumulated dose t o various organs of the body and helpful in the prevention of overexposure t o the individual. t o be more alert in avoiding unnecessary exposure to ion iz lzl g radiation. If the meter i s worn a t all times by each person, it could provide a m e a m of estimating exposure during emergency conditions resulting from radlation accidents o r military use of atomic weapons. It should cause a person Some of the disadvantages of placing dosimeters on every person i n the population The cost of the meters, t h e i r servicing and callbration, and of reporting and maintaining the records of dose would be very great. In many cases the patient, rather than the doctor, would be inclined t o make the decisions relative t o the medical application of X-rays and 7-rays. Sometimes it is desirable not t o inform a patient of his physical condition; the dosimeter record might reveal such information t o the patient. Unless appropriate meters were used properly, they would furnish data that i s misleading and of Uttle value. wide range of sensitivity; they would have t o be rugged, taqerproof, and convenient t o wear; they would have t o be worn a t the proper location for each planned exposure to ionizing radiation. In some cases the radiologist might hesitate t o give t o a patient equipped wlth a dosimeter w h a t he considers t o be the required dose because of fear of ll tiga tion. For a small fraction of the same expense and effort more accurate information could be obtained on the genetically significant dose by the application of sampling techniques rather than t o t d l population sampling. Of course a record of the medical exposure from ionizing radiation received by the The meters would hzve t o have a entire population would not require that a dosimeter be assigned t o each individual. this infomation could be obtained directly from those administering the medical exposure

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by requfrFng that all medical sources of ionizing radiation be licensed and by spec if fix that i n order t o retain such license, all medical exposures must be reported t o an appropriately designated central agency. rea-s, using appropriate instruments AuPished the medical man, o r they could be calculated from basic data Furnished by Task I. on an ixdividualbasis -- i n which case it would serve some of the useful functions of an individual personnel monitoring program as outlined above -- o r it could be kept on an impersonal basis (no names of individuals furnished the central agency). many of the disadvantages listed above could be avoided but it would be more difficult to verify the accuracy and punctuality of the data furnished the central agency. After a review of some of the pros a.nd cons w i t h reference t o direct measurement and recording of the exposure t o ionizing radiation received by the entire popuLation -- either indiViduaUy or collectively -- it seems clear that although, perhaps eventually, a more comprehensive system of personnel monitoring o r auditing should be developed, it would be preferable t o proceed first with a less expensive, less complicated, and more immediately operative survey of the radiation exposure received by a small but representative saqle of the population. as those of a universal survey except that if only 1/2$ of the total population is examined, the difficulties encountered are reduced almost by a factor of 200. assmed that unlimited funds will not be available for this sunrey and that best estates of the significant genetic dose received by the population at large can be obtained from a carefully planned and well directed survey of a representative sample of the population The exposures so reported c o d d be based on instrument The data could be kept by the central agency In this latter case The problems of a sample survey a r e essentially the same In any case, it is - _ rather than expending the same effort and funds in conducting a poorly plamed and executed study of a larger population. i s Various Methods of Direct Sampling DOES q HZ VU des.- -: 1 - P o l l of persons selected a t random or living in typical comm b. by personal contact c. by furnishing instruments b. by personal contact c. by furnishing instruments 2 - Poll of medical men selected a t random or practising i n typical communities. 3 - Poll of institutions selected a t random o r located in typical cammunities. b. by personal contact c. by furnishing instruments

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1 - Poll of Individuals ina Sample of the Po y h tion Theoretically it would be desirable to poll all members of tke population t o obtain information on exposure t o ionizing radiation but practically, because of limitations of cost and numbers of trained surveyors available, better results c a n t i expected with the sane effort and cost from apoll of carefully selected, characteristiz segments of the sopulation. Apoll of persons selected a t random or of all individuzls living i n communities selected a t random has ideally certain advantages over apoll zt the sources of …