-35-
had been leached out of the top layer of the soil and that
the longer-lived radioisotopes were still present.
This
interpretation could account for the deviation observed in
the latter portion of the plot for the decay of mixed fission products.
Levels
and Decline of Gross Beta Radioactivity at
Other Islands of Eniwetok Atoll
The amounts of gross beta radioactivity of the land
plants collected at other islands of Eniwetok Atoll
from
March 1954 to April 1956 are given in Appendix Table D; the
values for the plants collected from May 1956 to July 1957
are given in Appendix Table E.
Before the Nectar detonation
the highest amounts were in the leaves of plants collected
at Janet Island on April 4,
1954;
the average for eight
samples was 149 ywc/kg of wet tissue,
384 uc/kg.
the range being 8.4 to
The lowest amounts of radioactivity were found
in two coconut meat
(solid endosperm)
samples from Henry
Island; these samples averaged 0.30 uc/kg.
In general the
highest levels of radioactivity were found in the plants
collected on Janet,
Olive and Vera Islands.
These levels
were significantly higher than those on Belle Island.