By X-ray detection
Sore
0.04 pCi/g or less
By alpha detection
239,240,
0.02 pCi/g or less
RESULTS
Data are presented for the results of the analyses of the samples
collected by LRE in the Marshall Islands in 1974 and 1975 and on Christmas
Island in 1975. Appendix Tables 1 through 37 give the data for single
samples. Tables 3 through 6 and Figures 3 through 7 in the text present
summarized data usually in the form of the mean + 1 standard deviation for
several samples. The data will first be presented atoll by atoll and will
then be summarized by comparisons between atoils by selected sample types.
All data are given as picocuries per gram of dry weight, except where
expressty noted.
Christmas Island
The sites at which samples were collected in August, 1975, are shown in
Figure 2. Samples were analyzed for gamma-emitting radionuclides only. Seventeen naturally occurring or fallout radionuclides were detected in the samples
analyzed, but only naturally occurring 40k and 238U, and the fallout radionu-
clide 137¢s were present in more than 20% of the samples. Va pues for these
three radionuclides are given in appendix Tables 1 (plants),
(fish and inver-
tebrates) and 3 (soil).
Usually 40K was the most abundant ragsgnuct ide ina
sample and of the eleven fallout radionuclides detected only
Cs was present
in concentrations greater than 1 pCi/g. Levels of
Cs above 1 pCi/g occurred
only in Scaevola leaves (5.7 pCi/g) and unidentified leaves (32 pCi/g) from
plants collected near the airfield wash-sump and in bone (1.6 pCi/g) from
bonefish taken off London.
The airfield wash-sump was used during the Dominic
test series in 1962 to receive the wash-down water from aircraft used to
collect air samples from the radioactive clouds produced by the detonations.
The results of these analyses indicate,as noted by Seymour (1975),that
“only trace quantities of fallout radionuclides are present at Christmas Island
and the amounts are significantly less than the naturally occurring radionuclides.
Kwajalein and Wotho Atolls
DOE ARCHIVES
Samples from Kwajalein and Wotho atolls were collected incidental to a
trip to Bikini Atoll in April 1975. Results of the analyses of these samples
of plants, soil and coconut crabs for gamma-emitting radionuclides, 90Sr and
OPu are given in Appendix Tables 4 (Wotho) , 5 (Kwajalein) and 6 (Kwajalein
coconut crabs). Naturally occurring 40K is the most abundant radionuclide
present in the plant samples. Concentrations of 40K in pCi/g (dry) weight
ranged from 2.4 in breadfruit leaves from Wotho to 40 in coconut milk from
Rigej] Island in Kwajalein Atoll. Cesium-137 was the predominant
radionuclide. Most plant tissues had between 0.5 and 2.5 pCi of
gram of dry weight.
fallout
37Cs per
The seeds and rind of a papaya fruit from Wotho Island
had 12 and 15 pCi of 137Cs/g.
Strontium-90 levels were Tess than 1 pCi/g and
239,240Pu values ranged from 0.03 to less than 0.002 pCi/g in plants from
both atolls.
Soil levels were slightly higher with a maximum of 0.16 pCi/g