SHORT TERM BIOLOGICAL FATE, PERSISTENCE OF RADIOACTIVE FALL-OUT
THE SHORTER-THERM BIOLOGICAL HAZARDS OF A FALLOUT FIELD
from
Zero
[6].
Furthermore,
the
the biological evele [7].
&
‘
9
3
\
residual fallout contamination as compared to distance of the sampling site from NTS, and the degree of residual
\
\
\
0
RESIDUAL SOIL CONTAMINATION (uc/H?) 1954
ar
0.75
Jn summary wecan describe the biological
availability of radioactive fallout as follows:
First, it was found during participation in the
weapons testing program that the predominant
size of fallout particles greater than 100 microns
in
diameter
decreased
with
distance
from
Ground Zero while the less than 100 micron
material did not docrease but remained the
same or increased with distance up to 200 miles
REFERENCES
0.03
« Linppera, R. G., et al.
3 “
2
SACKRABBIT
o
3
z wo]
$
3
z
~
Ro
~
“0
DISTANCE
60
FROM
oo
ime
Ms (MILES) °
50
Ts
i]
DISTANCE OF SAMPLING SITE FROM HTS
“eo
“
zs
tt
Fieure 9.—The occurrence of radiostrontium in the
A feasible explanation then is that the arcumulation of radiostrontium, for instance, is
related to particle size and that because the
plant acts as a selective collector of very small
falloutparticles, the intake of radioactive debris
by animals during grazing tends to be similar
over a great distance and appears to be independent of the total fallout. The amount of
any specific isotope present is dependent upon
the physica) and chemical behavior of its iso-
bones of Jackrabbits sampled in spring 1954 from the
midline of residual fallout contamination as compared to the distance of the sampling site from NTS,
and the degree of residual soil contamination [8).
topic precursor during fallout particle formation, Therefore, the amount of any specific
isotope at any particular location within the
fallout pattern will be highly variable, and the
oecurrence of areas in which the biological
accumulation of that isotope is high are to be
anticipated.
The Uptake of Radioactive
. Linpsere, R. G., et al.
Environmental and Bio-
logical Fate of Fallout from Nuclear Detonations
in Areas Adjacent to the Nevada Proving Grounds.
Operation Upshot-Knothole, Project 272, Report
{MILES}
Fraune 7.-~The relationship of distance to the occurrence
of radioiodine in the thyroids of kangaroo rats con~
taminated by radioactive fallout, and to the occurrence of
radioiodine inthe thyroids af jackrabbits contaminated
by a different fallout (1).
Larson, K. H., et al.
Fission Products by Radishes and Ladino Clover
fron Soil Contaminated by Actual Subsurface
Detonation Fallout Materials. Atomic Energy
Project, University of California at Los Angeles
report No, UCLA-272, 1953.
“
“
RACESTRONTUM
“en —
tO
The Factors Influencing
the Biological Fate and Persistence of Radioactive
Fallout. Operation Teapot, Project 37.1, Report
ITR-1177, 1955.
TOTAL BETACANMA
a
fission products such as cerium, cesium, ruthenium, and zirconium are under study.
20
300
OISTANCE FROM NTS (MILES)
environmental contamination{4].
Fieure 6.~-Fission product distribution in tissues from
kangaroo rais sampled after two nights grazing (D,
D+), in a fallout area, expressed as a function of the
distance of the sampling site from Ground Zero (1).
which are measuredin our samples. Theracdioactive life of the precursor and its chemical
characteristies will determine how the daughter
product is finally distributed as fallout material.
The question as to the fate of other specific
hmm
oo
Fraure 8.-—The occurrence of radiostrontium in the bones of jackrabbits sampled in fall,1966 from ihe midline of
»
«OS
po
—
.
LON KANGAROO RAT
o
80~
DISTANCE FROM GROUND ZERO (MILES)
of approximately 20 microns.
1
Z
204060
Second, the majority
of particles retained by foliage were belaw 44
microns in diameter having an average size
THYROID ACTIVITY (muc/GRAM WET WEIGHT)
r=3
&
2
T
we
201
RACIOSTRONTIUM DIS/MIN/GM BONE ASH
and, therefore, potentially more available lo
ANIMAL ACTIVITY imue/GRAM WET WEIGHT)
a
2+
N\
NN
PLANT ACTIVITY (myc/GRAM DRY WEIGHT)
.
203
*
3
smaller size material tended to be more soluble,
GI Tract
PLANT,
Ground
RESIOUAL ENVIRONMENTAL CONTAMINATION (m/br BETA- GAMMA) (955
110,
042
233
O18 fon oor
——<——
WT-812, 1953.
. Quarterly
Report of Progress,
Atomic _Knergy
. Quarterly
Report of
Atomic
Project, University of California at Los Angcles,
report No, UCLA~357, December 1955.
ox
a
Progress,
Energy
Project, University of California at Los Angeles,
report No. UCLA~320, December 1954.
. Taney, (. T,, eb al. Distribution and Character-
a
202
istics of fallout at Distances Greater than 10
miles from Ground Zero, Operation UpshotKnothole, Project 27.1, Report WT-811, 1953.
. Baurmasn, L., et al, Distribution and Characterization of Fallout and Activity from 10 to 160
miles from Ground Zero. Operation Teapot,
Project 37.2, Report ITR-1178, 1955.