“0.21 uc Cs!*" subtracted” was obtained. Ridvesidual spectrum below
.4 Mev is undoubtedly due partly to the fact that the Cs and Zn phantom
spectra are not exactly identical to the in vivo Cs and Zn spectra. It is
felt, however, that the burdens of two subjects calculated in this fashion
are correct to at least 5 per cent.
Calculating the body burdens of the five subjects who had been mez
ured only in the standard chair presented a problem. The standard chair
position cannot be calibrated with a source and a presdwood phantom sinc
all volumes of the body are not at the same distance from the crystal, a
condition which is assumed when a person is placed on the one-meter arc
Since administration af the pertinent isotopes to the subject was
deemed unadvisable, the standard chair position was cross calibrated to
the one-meter arc position using the gamma-ray spectra of Subjects 5
and 8 in the following manner. The appropriate K gamma spectrum of
a control subject of the same height and weight was subtracted from the
gamma-ray spectrum obtained with Subject 5 in the chair and on the arc.
The resulting net in vivo zn® and Cgt37 spectrum, from 600 kev to 1.3 me
obtained with the chair
pc
position was 4.] times the net in vivo Zn® and Cs!
spectrum obtained on the arc. (See Fig. 22) The same ratio of 4.1 was
found for the spectra of Subject 8.
The standard chair gamma-ray spectra of the five subjects were
analyzed using the identical peel-off procedure digcussed above for the
one~meter arc technique above and demonstrated with Fig. 21 except that
the part of the spectra falling below 600 kev was neglected and the chair
to one-meter arc ratio was taken into account.
The values calculated for each subject were given by Table 9 abov
To investigate the gross distribution of Zn® in the body, gammaray spectra were obtained of Subject 5’s feet, abdomen, and head by mere
placing the crystal near the sites in question. The results, shown in Fig.
demonstrate that Zn/C 5137/K* ratios do not vary widely.
In order to determine the effective biological half-life of the isotc
involved, the Marshallese were supplied with suitable containers and re-
quested to submit their excreta. However, due to sight seeing trips, reporters, newsreel people and other extraneous activities, some samples
were lost, and no samples could be regarded as representative of excret:
rate over a definite period of time.
In order to gather at least some approximate information the sar
ples were treated as follows: the K, Cs!*’, and Zn™ content of each speci
was medsured and the Cs}*7 and zn® values were expressed in terms of
per gram of K. Since the Marshallese were ona standard American: diet
5012135
3
a
‘t
{