Figure 68. Shadow-shield whole-body counter (gamma spectroscopy) in new trailer,
with Marshallese subject being counted.
computer. In this program a library of spectra obtained by calibrations with the plastic phantom is
used, but the gammaenergy 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 burdensof radionuclides has been described by Cohn
and Gusmano.*!
Asin the previous surveys, both the population
exposedto 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
living on anotheratoll, Ebeye, were brought back
to Rongelap and included 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.
Radiochemical Analysis of Urine
In addition to the whole-body counts, information pertinent to the internal body burdens was
obtained by radiochemicalanalysis of urine specimens for *°Sr and '*"Cs, carried out by the Environment Studies Division, Health and Safety
Laboratory, AEC, New York.* Twenty-four-hour
urine specimens were 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
analyzed first for *°"Cs by gamma-ray spectroscopy
by counting the wet ashed sample on top of an
8 x 4-in. Nal (TI) crystal. Then the residues were
dissolved and analyzed radiochemically for '°"Cs
and °°Sr. Calcium was determined by the oxalate-
permanganatetitration method.
*Weare grateful to Mr. Edward P. Hardy for carrying out
these analyses.