242
S.H. COHN
was detected and measured for the first time in the Marshallese in 1961.
Its level is very low and was masked previously by the higher levels of the
other radionuclides. As mentioned above, many other fission products and
some other neutron-induced activities are present in the marine and terrestrial environmental samples, but their levels in man were too low to
detect in this situation.
C.
ESTIMATION OF BODY BURDENS
The body burdens of fission products in the Marshallese have been
assessed in three ways: by whole-body y-spectrometry, by radiochemical
analysis of the urine or bone, and by estimation of body burden from dietary intake. The method of choice is the direct in vivo measurement with
the whole-body spectrometer [7]. This method is, of course, restricted
to the analysis of y-emitters. A “portable'' (20 t) whole-body counter was
designed at the Brookhaven National Laboratory and transported aboard
_ a ship to the Marshall Islands in 1958, 1959 and 1961 to measurethe levels
of internally-deposited y-emitters in the radioactively contaminated population [8], Details of the experimental procedures and the automatic data-
handling techniques for analysing the complex multi-component spectra
have been presented [8]. A typical y-spectrum for an adult Marshallese
male, as obtained with the whole-body counter in 1961, is shown in Fig. 2.
VQ
°°
TIT
TTT
s™ (117pe)
a
TOT
A-MARSHALLESE MALE
AGE 6S yr, WEIGHT 70 kg
—
at
z
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w
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3
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om
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7
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£
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8-U.S.MALE, MEDIGAL TEAM
‘ WEIGHT 77 kg
AGE £1 yr,
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=
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118
138
158
ENERGY (Mev)
Fig.2
Cai
a,
2
om
re
Bett
a
4
cn
Specurum of typical Marshallese adult male compared with that of member of the US Medical team