a 39 » «ef toe Figure 68. Shadow-shield whole-body counter (gammaspectroscopy ) in newtrailer, with Marshallese subject being counted. computer. In this program a library of spectra ob- tained by calibrations 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 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.* Twenty-four-hour urine specimens werecollected 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 exposed to fallout in March 1954 and the unex- analyzed first for '**Cs by gamma-ray spectroscopy were counted. An effort was made to count every 8 x 4-in. Nal (TI) crystal. Then the residues were posed population currently living on Rongelap resident. In addition, some Rongelapese currently living on anotheratoll, Ebeye, were brought back to Rongelap andincluded in the survey. Members of the AEC and Trust Territory medical teams were also counted. A total of 179 people were counted in the 1965 survey. by counting the wet ashed sample on top of an dissolved and analyzed radiochemically for '*’Cs and *°Sr. Calcium was determinedby the oxalatepermanganate titration method. *We are grateful ta Mr. Edward P. Hardy for carrying out these anailvses. ;