WwW ~J ‘Health Physics Pergamon Press 1963. Vol 9, pp. 15-23. Printed in Northern Ireland 0052 AOL 2S USE OF A PORTABLE WHOLE-BODY COUNTER TO MEASURE INTERNAL CONTAMINATION IN A FALLOUT-EXPOSED POPULATION* S. H. COHN, R. A. CONARD, E. A. GUSMANOand J. S. ROBERTSON Medical Research Center, Brookhaven National Laboratory, Upton, L.I., N.Y. (Received 19 February 1962; in revisedform 7 June 1962) Abstract—The evaluation of body burdens of radionuclides in large populations is a health physics problem of considerable importance. Measurement with the whole-body y-spectro- meter provides the best technique for this evaluation. A “portable” whole-body counter, such as the BNL model, makesit possible to carry out studies in remote areas. The report presents the technique of carrying out, in the field, a survey of internal con- tamination in a population. The study used to illustrate the technique is the survey made in 1961 of the y-ray spectra of a group of Marshallese people, some of whom hadaccidentally been exposed to fallout from nuclear detonation in 1954. The results of the latest study are presented in this report and comparedto the findings from previous field studies among the Marshallese made in 1958 and 1959, Possible directions in which the developmentof this technique might proceed, and other possible applications of whole-body counting in the field are also discussed. Rongelap Atoll who were accidentally exposed to fallout in 1954. Early evaluation of the body INTRODUCTION THe evaluation of body burdens of radio- burdens in these people was carried out by nuclides in large populations is a health physics radiochemical urinalysis, which is time-consuming anddifficult. In 1957, several Rongelap problem of considerable importance at present. Increasing production and use of fissionable people were brought to Argonne National materials, and renewed nuclear testing both contribute to contamination of the atmosphere, Laboratory where it was demonstrated that their body burdens of gammaemitters could be measured in the whole-body counter. (s18? and Zn® were shown to be the prominent isotopes in the Marshallese at that time. The Rongelap people, originally evacuated to water supplies and soil, and thus to increasing body burdens of radionuclides among large populations. Concomitant with the application of nuclear materials is an ever-present possi- bility of accident. The importance of keeping anotherisland in 1954, were returned to their the level of body burdens of various radio- nuclides in the general population, as well as in specific exposed groups under survey, is manifest. For large scale surveys, measurement with whole-body gamma counters (both liquid scintillation detectors") and crystal detectors?) has proved to be the mostsatisfactory technique. An example of the successful application of this homeisland in July 1957. Since the island and was the study of the Marshallese people of surveys to ascertain the level of internallydeposited y-emitting isotopes. In 1958, 100 Marshallese people were counted, and the procedure was repeated oneyearlater to obtain the indigenousfood sourcesstill had a low level of persisting radionuclides, continued evaluation of the body burdens in these people was of considerable interest. A portable whole-body counter was designed and constructed at Brookhaven Laboratory and transported to the Marshall Islands whereit has since been employed during the annual medical technique, using a portable whole-body counter, * Research supported by the U.S. Atomic Energy Commission. 15 MEPO SITORY BNL RECORDS coutection ZAKS#AzL BOX No. UG MEDICAL eee The Medical Research Center ISLANDS. ‘Brookhaven National Laboratory _ DEPT. PUBLICATIONS | Upton,L.L, ‘New York . Sm fem

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