35 suming and difficult. In 1957, several Rongelap people were brought to Argonne National Laboratory, where it was demonstrated that their body tain gamma spectra on 227 people. Details of the shown to be the prominent isotopes in the MarShallese at that time. ~ and data-recording apparatus. The gamma-ray exposure and findings of these medical studies have been reported.'' During the 1961 survey the portable shield was used in conjunction with an improved detection burdens of gamma emitters could be measured in the whole-body counter. Cs'* and Zn" were spectra of 110 people were obtained. Half the people measured had been exposed to the fallout The Rongelap people, originally evacuated to in 1954; the other haif were unexposed. another island in 1954, were returned to their home island in July 1957. Since the island and the indigenous food sourcesstill had a lowlevel of persisting radionuclides, continued evaluation of the METHOD body burdensin these people was of considerable interest. A portable whole-body counter was designed Shielding was provided by a 21-ton room with walls constructed of laminated '4-in.-thick steel panels bolted together, which can be disassembled. The inside dimensionsof the room are 55 ft and and constructed at Brookhaven National Laboratory and transported to the Marshall Islands, 6 ft high. Figure 52 showsthe steel room (as set up whereit has since been employed during the annual medical surveys to ascertain the level ofinternallv-deposited gamma-emitting isotopes. In 1958, 100 Marshallese people were counted, and the procedure was repeated oneyear later to ob- for the 1959 survey). In 1961 the room wasset up in the cargo hold of the Rogue (Figure 6). Along with the steel room, an air-conditioned prefabricated wooden room 7x8 X LO ft was set up to house the pulse-height analyzer and other elec- Table 13 Frequencies (in Percent) of Gm Factors in Various Populations Gm Factor Population United States White Negro Athabascan Indians( Alaska) Artic Village Fort Yukon Total Eskimos (Alaska) Wainwright Africa Yoruba Fulani Bashi Pygmies Micronesia Rongelap Atoll Surinam No. b x 303 50.8 91.8 17.5 58 51 100.0 100.0 0 3.9 41.4 31.4 100.0 Av 1.8 Av 364 109 98.1 97.5 3.0 36.7 Av 6.0 like 0 27.7 0 0 Oo 50 100.0 20.0 35 35 37 120 100.0 100.0 100.0 100.0 100.0 100.0 94.6 . 100.0 0 0 0 0 100.0 94.3 35.1 100.0 149 100.0 97.3 0 43.6 0 Djuka Negroes 35 100.0 100.0 0) 62.9 Javanese 20 100.0 100.0 86.7 13.0 26.7 50.0 Carib Indians 19 100.0 79.0 32.6 0 iS 100.0 0 apeee ene oe ee 8. Ovyana Indians Ay ec