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PERSISTENCE OF TRITIUM AND CIN THE PACIFIC PROVING GROUND
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Table 3. Tritium content of samplesfrom Igurin, Japtan, Bitjiri and Aaranbiru Islands (in T.U.)
Samples
Messerschmidia
argentea, Igurin
Pisonia grandis,
Igurin Is.
Cocos nucifera,
old nut,
Igurin
young nut,
sametree
Wood
Loose
Bound
water
118 +22
water
Leaves
Loose
Bound
water
water
Ochrosia
oppositifolia
990 + 34
80 +40
50
80
40
580 + 40
Messerschmidia
argentea,
Biijiri
3.00 + .10,°.°
°
(Husk)
75 +30
130 +40
nt
Live
Mes
Mes.
C.
Mess
|
(young)
(Meat)
330 + 20
70
70 +40
40
69 +15 170 + 20
analyses. Duplicate sample results are given in
Table 4.
Table 5 presents the tritium content of water
samples collected at Eniwetok Atoll. The
tritium content of a late 1963 seawater sample
from the Marshall Islands was reported by the
JAEA“andis includedin this table.
The tritium content of animals collected at
four locations on Eniwetok Atoll is given in
Table 6.
water
240 + 30 116 + 19 330 + 40 132 + 23 300 + 30 50 4 25 3.444 0.10x%
(old)
61 + 15 277 + 32
young nut,
Japtan
Aaranbiru Is.
—
Bound
(Meat)
150 +30 160430 84 + 24
160 + 30
Pisonia grandis,
water
Soil
740 + 90
76 +26
Guettarda
speciosa,
Aaranbiru Is.
water
Loose
62 +26 391 + 28
(Husk)
Japtan Is.
Cocos nucifera,
water
190 + 24
Messerschmidia
‘
argentea, Japtan 147 + 26 240 + 34
Pisonia grandis,
Japtan Is.
Litter
Loose
Bound
:
™4C values are also included in this
table.
In order to characterize the soil-bound source
of tritium and 44C, the values for five soils are
given separately in Table 7, and have appeared
in the tables with the ecological series. Tables
8 and 9 contain the 'C values for plant samples
collected on Eniwetok Atoll and are arranged
in the same ecological sequence that was used
in Tables ! through 3.
DISCUSSION
Background information
The mode of entry of water into plants is
mainly through absorption of water from the
soil by roots. The mechanism involves both
active and passive absorption although the
passive route is the most important in satisfying
the water requirements of the plant. Large
amounts of water are absorbed each day bythe
root systems of plants, transported through the
stems, and released to the atmosphere by
transpiration. Most of the water absorbedis lost
in transpiration, and less than | per centwillbe
used in the synthesis of new organic matter.
Mess
———
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