206
THE SHORTER-TERM BIOLOGICAL HAZARDS OF A FALLOUT FIELD
,
Part
Plant
.
Papaya... - 0. .- 0000
hn
yO
do
‘
a
Ripe...------
2
fennel
a7
.
occeeecnccenewnceene
DK
Ripe coconut... 20...
at
:
Green coconut. —...... |
Sprouting coconut... ..
-
Bniaetok Rongelay Sito
1. 02
37
2. 64
1
HEAVES — ~~
Pandanus.._.—-omen Green keysMB-
tg
Hntwotak
17
2. 87
root
4B
Eniw
19.2
45
57
87.4
12.0
2, 32
Portulaca.......---.-- Nhole plant... 2..----24..
-)
Arrowroot...---c0---- { tems, leaves
Tubers.
y
|
i
Ge
_Galen|
PLANTS * (efmfke x 1r8)
'
How
.
‘
b
:
'
‘
_
Eniwetak |
Gojen
ein Laken
|
Enlnetak
.32
Cistern..-.----- a ~ -- eee [eee eee fen ee [ee een
.
. oe
Well... -----------+
:2
:
.
.
.
.
.
:
‘
:
tie:
|
|
Sette
Liklep
NDA |..--------
0. 008 |..--------
a1
NDA
NDA
- 09
0. 08
RDA
- 03
NDA
Ovean.....---Lagoon. -.--.
: i
84
.
.
Rito
liter x 10-*)
( e/m/liter
WATER?
y
-
38
3
:
Rongotap |
SOURCE
pepra (IN.)
~
.
.
.
. 09
. 06
02
- 07
,
L6
—
meee lnm
06
07
18
1
'
s
:!
a counts were corrected for the counting efficiency of Sr. Y%,
and water in May 1956.
ross beta activity of plant samples was determined in April 1956 and that of soil
:
Banana...............\
a
.
1. 05
5. 26
WATER AND SOIL SAMPLES ¢
STRIAAnsm ioe
ia
ot
Tarun 2.--GROSS BETA ACTIVITY IN PLANT
Se ae
sera Sa
om
1. 26
(25
55
|.
.
:
Coconut... ..-----eee |
3. 05
32
. 69
207
CONTAMINATION OF PLANTS, ANIMALS, SOIL, AND WATER
SAMPLES?
Taste 1.—GROSS BETA ACTIVITY IN PLANT, WATER AND SOIL
Bark....-........-..
Taro... enna eenn enon (reeves roots with soil... ..}--...2--|o-. wwe de ae
with the activities of the respective soils as
shown in Table 2.
The gross beta activity of well, cistern,
ocean, and lagoon water is shown in Table 2.
The activities were either imperceptible or of
a low order of magnitude.
To describe the downward movement of the
activity, profile soil samples were obtained in
increments to a depth of 56 inches. As shown
in Table 2, the greater part of the beta activity
appeared fixed to the upper surface of the soil;
the remaining part diminished sharply and pro-
Sry,
*» All counts were corrected for the counting efficiency of
1956 and that of soil and water in May 1956.
» Gross beta activity of plant samples was determined in April
« NDAindicates no detectable activity.
|
Tanne 3.—AVERAGE GAMMA DOSE RATES
8
=
gressively at deeper levels. The bulk of the
activity appeared to be firmly absorbed to the
soil gince it resi
"
i
i
the heavy weeto.which,these “aundaove
subject. .
for beta decay of mixed fission products [4]
predict that 80 percent of the gamma.activity
<0. 05
7
6
2.4
Table 3 lists the gamma dose rates found on
Calculations based on the Hunter-Ballou curves
6.04
.7
:
the island survey; levels observed 1 year before
activity was reduendare included. The gamma
over the 12-month period by 74 +8 percent
a
8
J
AY
FROM PREVIOUS AND CU RReN 7 SURVEYS
11 months 23 months Remaining
“Garfae) activity,Cpet(anefar)”
Island
Average..-----» _
ae
a
. 09
. 28
~
“e
5
13.
23
12
23
*
ag:
is lost by radioactive decay over this interval.
This decay was obviouslythe significant factor
in reduction of the gammafield rather than the
leaching of nuclides to deeper layers and their
i
i
jace
7
fissi
eroding me the addjace nt waters. :
_ission
The ong-lived isotopes of mixed internal
products, which present the greatest
radiation hazard to human inhabitants of a
contaminated areca, were analyzed in plant,
soil, and water samples. These isotopes were
rare earths, Sr®, Csi”, and Rui
the total
and comprised the total detectablefission prod-
uct activity remaining 2 years after the
nuclear detonation.
In Table 4 the relative contribution of the
nuclides recovered from plant, soil and water
are recorded, The primary contaminating iso-
tope in coconuts, papaya fruit, pandanus keys
and arrowroot tubers was Cs". Significant
quantities of the rare carth components (16 to
18 percent) were recovered from papaya and