concentrations in plant samples and
Whenever the number of samples is
from the average measured concentration
large enough,
in the associated O- to 25-cm soil
are plotted against concentrations
profile.
in plants from the same sampling
factor,
We define the concentration
CF,
site;
as
soil concentrations
the results are analyzed
with linear regression methods.
CF = pCi/g dry plant
These linear regression results
pCi/g dry soil
are 'statistically significant" at
To reduce the variability in average
the O.l-level of a standard F test.
soil concentrations
For each combination of nuclide,
(used to calculate
the concentration factor), we used 2
plant organ,
QO- to 25-cm soil profile that encom-
statistically significant regression
passes a large fraction of the effec-
equations are compared
tive absorptive root zone rather
of the calculated concentration
than
to the median
the deeper O- to 55-em profile that
factors and a single representative
encompasses the entire root zone.
concentration factor is assigned.
Concentration factors calculated on
Predictions of radionuclide
the basis of the average soil concen-
levels in’ foodstuffs can be made
tration in the upper 25 ecm of the
from concentration factors if
profile are somewhat greater but do
measured soil concentrations are
not differ substantially from those
available;
based on the deeper profiles
ratios are also needed if
lL and 2).
(Tables
All concentration factors
reported here are
therefore those
however,
concentration
the only
available data are from mature leaf
samples.
The concentration ratio
derived from average O- to 25-cm soil
is defined as the ratio of
concentrations.
centration in fruit to the concen-
The average O- to 25-cm soil
tration in leaves of
or,
weighted geometric mean for the
one species
separate concentrations,
leaves of another species.
profile.
than
measured at
throughout
the
Concentration values less
the minimum detection limit are
set equal to
the detection limit,
following the U.S.
Environmental
wet
Fagg,
oa
=
?soe
art
Gri
c=
Protection Agency technique.
as
the con-
the same species;
concentration is calculated as the
various increments
AANA
and species considered,
the concentration in leaves of
to the concentration in
We cal-
culted preliminary raties for all
available species from the 1975
Bikini survey.
However, because of
the small number of samples involved,
a statistical analysis of
results was not possible.
these