ft ‘hen Figure 68. Shadow-shield whole-body counter (gammaspectroscopy) in newtrailer, with Marshallese subject being counted. computer. In this program library of spectra obtained bycalibrations with the plastic phantom is used, but the gamma energy peaks extracted are not limited to those represented in the library. The program used was developed at Los Alamos*® for an IBM-704 computer, and has been modified for use on the IBM-7094 and the CDC-6600 computers. Its use in the determination of body burdens of radionuclides has been described by Cohn and Gusmano.*? As in the previous surveys, both the population exposed to fallout in March 1954 and the unexposed population currently living on Rongelap were counted. An effort was made to count every resident. In addition, some Rongelapese currently Radiochemical Analysis of Urine In addition to the whole-body counts, information pertinent to the internal body burdens was obtained by radiochemical analysis of urine specimensfor °°Sr and '*’Cs, carried out by the Envi- ronment Studies Division, Health and Safety Laboratory, AEC, New York.* Twenry-four-hour urine specimenswere collected from 23 residents of Rongelap Island and 5 residents of Ebeye Island. In addition, two pooled urine samples were obtained on Rongelap. The urines were analyzedfirst for '*"Cs by gamma-ray spectroscopy by counting the wet ashed sample on top of an 8 x 4-in. NaI (TI) crystal. Then the residues were to Rongelap and included in the survey. Members dissolved and analyzed radiochemically for ‘*'Cs and °°Sr. Calcium was determined bythe oxalatepermanganate titration method. were also counted. A total of 179 people were counted in the 1965 survey. *Weare grateful to Mr. Edward P. Hardy for carrving out these analyses. living on anotheratoll, Ebeye, were brought back of the AEC and Trust Territory medical teams