samples through the root zones of the
sampled trees.
From these data, we
The concentration factors determined from this survey are more pre-
developed concentration factors (CF)
cise and provide a better basis for
relating concentration in food prod-~
estimating the average radionuclide
ucts to. soil concentration,
concentration that would be expected
as well as
concentration ratios that relate the
from crops planted in certain regions
concentration in the vegetation (leaf)
within an island or on different
to the concentration in the edible
islands,
fruit, or the concentration in indi-
Despite the greater precision of
cator species (Seaevola and Messer-
concentration factors calculated from
schmidta) to concentrations in food
associated vegetation and soil data;
crops.
these values still show some variabil-
A separate report? discusses in
ity.
detail the results of the sampling
be accounted for by several factors
program and the calculation of CF and
acting either alone or in concert.
concentation ratio,
These factors include differences in:
In brief, the
distribution of radionuclides in both
e
the Bikini and Enewetak environment
was nonhomogenous.
Radionuclide con-
e
Tatas suet eee
Physiochemical properties of the
radionuclides;
over distances of only a few feet.
e
Soil management practices;
The results of our work during this
e
Irrigation practices; and
survey verified our thesis that
@®
Physiology, age, and prior his-
because of the wide variability in
soil concentration with location,
tory of the sampled plants.
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
Sale
Soil type, organic content, and
chemical characteristics;
centrations in soil varied greatly
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 vf-Eneu Island.
different sites but in the same
average soil concentrations were then
are a
used along with the concentration fac-
34,35
(see also Table 22, this
These
tors to predict the radionuclide
report).
j
'
py oS Se ate cea te
This remaining variability can
5009980
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