through the root cones of
sampled trees.
inh
The
rom these cata. we
Seveloped concentration Zsectcrs
(CT)
for
estimating ine average radionuciide
is well as
coneentraticn that would be expected
Irom crops zianted in certain regions
vegeration (lear)
~o the concentration in ine edible
“puit,
Jeter-
md trovide a better basis
cise
soncentration ratios that relate the
concentration in the
factors
mined irom inis survey are more >re-
relating concentration in ffo0a 7roda“ets to soil concentrraticn.
concentration
qo
samples
within an island or on different
islands.
or the concentration ia indi-
Despite the greater precision of
cator species (Scaevola and ‘'2sser-
concentraticn factors caiculated from
senmidia) to concentrations in food
associated vegetation and soil data,
crops.”
these values still show some variabil
~
A separate report. discusses in
ity.
This remaining variability can
detail the results of the sampiing
te accounted for by several factors
orogram and the calculation otf CF and
acting either alone or in concert.
concentation ratio,
These factors include differences in:
[In brier, the
distribution of radionuclides in both
e
the Bikini and Enewetak environment
was nonhomogenous.
Soil type, organic content, and
chemical characteristics;
Radionuclide con-
e
centracions in soil varied greatly
Physicochemical properties of the
radionuclides;
over distances of only a few feet.
@
Soil management practices;
The results of our work during this
@
irrigation practices;
survey verified our thesis that
e
Physiology, age, and prior his-
and
tory cf the sampled plants.
secause of the wide variability in
soil concentration with location, use-
One would, in fact, expect to see some
ful concentration factors can only be
variation in sampling conducted from a
calculated from vegetation and soil
specific tree merely resulting from
data sampled from the exact site.
normal biological variability.
Concentration factors derived from
In addition to the calculation of
soil sampled from the root zone of the
CF, the data from the large surface~
vegetation under investigation showed
soil sampling program? were used to
a greatly reduced range of values com-
determine average soil concentrations
pared with values developed earlier
in four regions on Bikini Island and
from vegetation and soil samples from
in the whole of Eneu Island.
different sites but in the same
average soil concentrations were then
area’’?>> (see also Table 22, this
used along with the concentration fac-
report).
tors to predict the radionuclide
-3Q—
These