£5 Althoughlevels of Zn”’ body burdens equivalent important fission product Sr’. Its levels can only to those found in the Marshallese (1.51 myC-kg body weight) have been observed in certain BNL reactor workers,'' the values in the Rongelap population were about 100 times those measured analysis of urine. Undoubtedlythe bremsstrahlung resulting from the Sr” body burdens in the Mar- kg body weight, just slightly higher than the pre- several gamma-emitting radionuclides in the Mar- in the members of the medical team. The mean level of Zn” in the medical team was 0.015 muC, be estimated from data obtained byradiochemical shallese contributes to the residual activity noted above. A studyof the levels of bodv burdens of the cision of the counter. and therefore not statistically significant (Table 17). shallese people indicates howthefission products The K content of the adult Marshallese male in man. Further, the biological turnover rate of these radionuclides in human beings can beesti- averages 2.12 g, kg. compared to the mean for the medical team of 1.72. The average K of a large group of male employees at BNL is 1.84 g- kg body weight.'’ The higher value for the Marshallese males reflects their well-developed musculature and lowfat content. as the value ofK is proportional to the lean body mass. Thus. the K values for the Marshallese females are generally lower, in the range 1.52 to 1.71 g kg body weight. As expected. the K concentrations measured in the children are somewhat higher than those of the adults. particularly among females. A newand veryinteresting hnding ofthis study was the determination of the presence of Co” in the Marshallese population. The mean level is fairly uniform,-about ‘* of the Zn” level. but the spread in values in any one group is large. There is a fairly consistent correlation between the Zn"? and the Co” values, which could very well reflect their common origin in the fish. snails, and clams of the Marshallese diet. The induced activity, Co”, had not been detected previously in this population because its verv low level was masked bythe relatively large peaks of the other radionuclides in the relatively short counting periods hitherto used. It was to reveal just such secondarylevels that the longer counting period and larger detector were adoptedfor the 1961 study. The residual gamma activity in the spectra re- maining after the subtraction of the major components indicates that there are some residual radionuclides present in quantities not sufficient for identification via their photopeaks. The adult groups all had approximately the same level of residual activity, while the juveniles had 25 to 50% of the adult levels. The residual activity values in the adult groups were at least 10 times the mean observed in the U.S. medical team. Unfortunately whole-body counting techniques have not been developed for external beta counting of the very move through the environment and accumulate mated, The survey made with the portable wholebody counter has been invaluable in monitoring the levels of internal contamination of gamma emitters in this population. The experience gained in this study should be ofvalue in future survevs among other populations. Summary and Conclusions In March 1961. a medical survey was carried out on the Marshallese people of Rongelap Atoll who had been accidentally exposed to fallout radiation / years previously. The medical team consisted of 10 medical specialists from the United States and 8 from the Trust Territoryof the Pacific Islands. A total of 267 Rongelap people were examined. most of them on Rongelap Island and some at Kwajalein and Majuro Atolls. Of this number. 76 were in the exposed group: 28 were children of exposed parents: and 163 were adults and children from the comparison population not exposed to fallout. The Trust Territory ship Roque was used to transport and house the team and in addition housed, in its cargo hold, the 2!-ton steel room with its electronic equipment for carrving out spectrographic analyses. Prior to the survey, at Rongelap a village meeting held with representatives of the medical team revealed that the people were still concerned and had some misconceptions about certain conditions that theyfelt were related to fallout such as fish poisoning and a sickness from eating arrowroot flour. The true nature of these maladies was explained to them. Somedissatisfaction wasalso expressed about the conunued ban oneating coconut crabs, but the people were assured that regular analyses for radioactivity would be run on the crabs and they would be notified as soon as the crabs were considered safe for consumption.