The major contribution to the terrestrial food chain comes from food such as
coconut, breadfruit, Pandanus, etc. Looking specifically at the terrestrial foods, coconut
contributes a major share of the dose because of its
137
Cs concentration and the high
intake of coconut.
3a
a3
a
DISTRIBUTION OF DOSES AROUND THE ESTIMATED AVERAGE DOSE
%
ne)
By
&
aes
eH
The doses presented herein are calculated using the mean value of the data
an
available for each parameter in the dose models. For example, model parameters include
aA
a
ih
body weight, residence time of radionuclides in the body, radionuclide concentrations in
either foods or soil, dietary intake (measured in grams per day), and fractional deposition
of radionuclides in body organs or compartments. Data for all of these parameters have a
§
ed
4
ie
Thus, the mean value calculated from the data does not
ty
represent the midpoint of the distribution but rather falls between the 65th and 70th
is
log-normal distribution.
percentile; that is, for a given parameter approximately 65 to 70% of the data points fall
below the mean value. Thus, if the mean values for the parameters are used in the dose
models and the data sets are log-normally distributed, the final calculated average doses
are also log-normally distributed.
For a more detailed discussion of the mathematical
evaluation of this problem, see Refs. 4 and 5.
The average doses presented here fall at the 68th percentile on the distribution; that
is, 68% of the population would be expected to have doses below this value. A dose equal
to twice the average falls at the 88th percentile and a dose three times the average falls
at the 95th percentile.
Thus, 68% of the population of most atolls would have a 30-y
integral dose less than those listed in Table 17.
Based on this analysis, there is about a
5% chance for a person to receive a dose that is greater than three times the average dose.
SUMMARY AND CONCLUSIONS
The doses we have presented are calculated from the date of the survey conducted
in September of 1978.
Because resettlement has not yet occurred at some atolls, the
doses for those currently uninhabited atolls will be reduced from those listed in Tables 16
and 17, depending on when resettlement might, if ever, occur.
The diets used to determine the daily intake of radionuclides are the most direct
data available on the current dietary habits in the northern Marshall Islands (see Tables 3
to 12). Lacking direct dietary data for many of the Marshallese, we elected to calculate
48