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CHAPTERil
Gross
A. Land Plants
Graphs 2 and 3 indicate the general levels of
activity of edible plants (pandanus, papaya,
breadfruit, arrowroot), and coconut meat and
milk at Rongelap Atoll together with their
decline of activity with time.:?
Tables 1 and 2 show the analyses made by
NRDLfortheir first survey in February 19552
Table 3 is based on the February 1956 survey.‘
Tables 4, 5 and 6 show the analyses by
HASL.: 6
a
Activity
The highinitial activity of the ‘edible plants”’
(Graph 2) was probably due to surface contamination caused by the direct fallout. The rise
in activity after a year after the fallout occurred
may be due to (a) sampling and counting variances, (b) the ability of some plants to concentrate Cs"? (see Section Radiochemical Analysis), (c) the increased availability of the
radioactive fallout material to the plants,or (d) a
combination of these factors. Initially the activity in the coconut milk and meat was less
than other edible plants, but the rate of decline
of activity has been less than for other edible
land plants due principally to the higher percentage uptake of this longer-lived Cs'*’.
Table 1—Summary of Gross Beta Activity in Miscellaneous Plant Samples*
AVERAGE ACTIVITY (uc/g x 108) ® >
ISLAND
Piant Mater.
Likiep
Grass... -.-..-.----.------25
2»
Utirik
Rongelap/ Busch
Eniaetok/ Labaredj;
Kabelle
Gejen
Lomuilal/ Bikar
|Eniwetak
2300
5300
1900
2100
68, 000
5600
180
400
3000
42
750
1800
670 {-.------~-|-------+--]------ +=} -- =e
f------- | ----- ef - ee seeee
140 JL... ----2-|----------|--------|----- eee
Coconut frond stem....---..|--------]----------f-------- +e [eee eee fee eee wee ne) see ne ne ene |e nee eee e ee
17 22 --e nee
180 |__...--.--]--------|---------Coconut shell_-_._..---.....{--_-----|----------[---------- |---| ---- wence [ee eee ee eee
Ta |..------.110 |..-----.-8.4 |_.-------Coconut husk...........--.L?
1.6
83 |_-------|----- aewee|-ne eee eee
HO {2-2-2 e sf e eee e ee fone ee ene fee eee fener ee ee
Coconnt sprout. _..-...-...-1..-2.---|-.-------B j...-----]----- we ene [eee e eee eee
Sprouted coconut roots_Coconntfeaf_..-....-.------[--. 2+...
400
Lukuen
1100
Vines... .-------- 2-2] = pene eee fen eee fee ee pene ee
© Wot weight.
» As determined on basis Us0s standards and empirica) scattering and absorption corrections.
*Oollections made about February 1, 1955. Data reported as of March 1, 1955.