ABSTRACT
A study was made to
determine the amounts of radioactivity in
marine algae, water and lagoon bottom sand collected at Eniwetok
Atoll during the period April 1954 to April 1956.
The highest levels
of beta radioactivity of algae collected after the detonation of a
nuclear device (Nectar) were
in
algae
from those islands closest
to the site of detonation and in the downwind path of the fallout.
With
time after detonation, the decline of radioactivity in the algae at Belle
Island was faster than can be accounted for on the basis of physical
decay alone.
In March 1955,
algae and bottom sand collected in the deeper
waters (20 to 140 feet) of the lagoon, one half to two
miles offshore,
contained as much or more radioactivity than samples collected in the
shallow water near shore.
The radioactive decay rates of algae samples collected from
Leroy and Henry Islands were greater than those of algae from other
islands,
indicating that there was less residual contamination from
previous detonations at these two islands.
Study of the radioactive decay rates of the algae at Belle Island
showed that the radioactivity was decaying ata relatively
low rate,
which became slower with samples collected late in the survey.
These
observations indicate that the longer-lived isotopes were being taken up
by the algae.
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