THE OCCURRENCE OF ANTIMONY-125, EUROPIUM-155, IRON-55,
AND OTHER RADIONUCLIDES IN RONGELAP ATOLL SOIL
INTRODUCTION
Since 1946 the Laboratory of Radiation Biology of the University
of Washington has conducted studies at the Eniwetok Proving Ground
to evaluate
the effects of radioactivity produced by the atomic
tests on aquatic and terrestrial
studies ” 2,3, 4,5, 8
organisms.
The
results
of
these
have shown that a definite relationship exists
between the amount and nature of the radioisotopes in the environment
and in the living organisms.
[In the present study, detailed analyses
were made of soil samples taken from several locations at Rongelap
Atoll
in July 1957.
The samples were examined for total radioactivity
as well as for isotopic content.
Gamma spectrum curves from the soil samples contained gamma
peaks which indicated the presence of one or more isotopes not previously reported in biological or soil samples from the Marshall Islands.
The gamma energies agreed well with those of sb i25 and Eu!55, which
are produced in very small amounts in y235 fission (0.023 per cent and
0.031 per cent
of
respectively,
approximately
samples
tervals
from
since
two
Sullivan),
years.
Rongelap
March 26,
19
Subsequent
Atoll
which
1954,
and
which
analyses
had been
showed
the
have
of
several
collected
presence
half lives
of
at
soil
inah
these<* ">
f°
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