- 51 -
general level of ra
dioactivity at Rongelap
Island, but does illust
rate the
. ’problem introduced by sample variation when too few samp
les are taken.
ane other soil sample from Rongelap Island cont
ained 1.7 uc/kg of top 3
7 inches of soil and agrees favorabl with tha
y
t expected from a consideration
of the values obtained in previous collections when radioactivity decline is
<7
taken into consideration.
The rate of decline of radioactive contamination in the combined soil
“:~
gamples from Kabelle and Labaredj Islands between the dates, March 26,
1054 and October 23, 1955 is best represented by a straight line on log-log
coordinates with a slope of approximately -1.6.
The decay curve for a
Labaredj Island soil sample extending through the same period of time 5
is expressed by the formula r=t i. 31 .
In both curves March 1, 1954 is
the date of origin.
Enibuk Island (Ailinginae Atoll) soil contained 1.2 yuc/kg of top inch of
- soil or an average of 0.61 uc/kg of top 3 inches of soil on October 23, 1955.
Thus the soil at Enibuk was about 1/3 as radioactive as was soil from
_Rongelap Island, a relationship which was reflected in the radioactivity
- / levels ofland plants from the same islands.
‘The sandat lowtideline at
- . Enibuk also contained about 1/3 as much radioactive contamination as did a
» Uke Sample from Rongelap.
At both Enibuk and Rongelap the radioactivity
“level. in the low tide line sand was about 1/18 that found in the island soil
(top 3 inches).
|
The levels of radioactivity in the top 6 inches of sand profiles taken on
the lagoon bottom off Kabelle Island varied from 1/3 to 1/1 that for the
UNIVER
Ape ge cc. mA
;
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