RR cach n So anhis .. Wilbal ons
no ravi«neeb teatayaeeach nr
i.
samples from Wotho,
:
and Kapingamarangi,
Ponape,
Tarawa,
contributed the major portion of the radioactivity.
collected at the
samples
same time
«40
Other
contained wi8l,185
radioisotopes identified with the 1958 fallout.
Some samples,
such aS coconut crab abdomen and whole fish from Wotho, contained gn°> , whereas others,
none.
such as land plants,
Some of the land plants
contained
contained measurable amounts
of the long-lived fission products Cs
137 and gr 7°,
The high~
est level of Sr 90 was found in a sample of coconut crab cara~pace from Wotho
isotope by the
reported by Held
(18 ywuc/g dry).
The concentration of this
carapace of land
crabs at Eniwetok has been
(1957).
The relatively rapid decay of beta radioactivity in
some of the samples collected in 1956 at Tarawa, Ponape and
Wotho (Fig. 2 A-E) indicates the presence of short-lived
isotopes.
A gamma spectrum analysis of one of the samples
(leaves and stems of a Messerschmidia plant from Wotho)
showed that Zr
95 _1,95
this sample.
Thomas etal.
were the predominant radioisotopes in
(1958) found that these isotopes
contributed approximately 84 per cent of the total radioactivity in a duplicate sample.
The presence of short-lived
isotopes in the 1956 samples indicated recent fallout at
these islands.
yh”
qar ARN