lower and if it should be as short as 20 y, the estimated doses would be 64%
lower.
We have experiments under way to determine the environmental
residence time and when data are available, they will be included and the
estimated doses adjusted accordingly.
We have not included shielding from external gamma exposure thatoccurs from
the housing structure and from coral gravel that is commonly spread in a 10-~ to
15-m area around the houses. The people spend considerable time in and around
their houses.©
Therefore, a significant reduction in the external exposure
around the housing area can occur. This reduction from shielding by the house
can be a factor of 2 based on a 30 to 40% occupancy. If coral gravel is spread
around the house, another factor of 2 reduction can be obtained. Depending on
the location of the housing, the use or non-use of coral gravel, and the
percentage of time spent in or near the house, the external dose reduction
could range from 15 to 80%.
(4)
We have used the average values for all of the parameters in the dose models
and the resulting doses fall at about the 68% point on the distribution. If we
used the median values to estimate the doses for the
midpoint of the
distribution, the doses would be lower.
(5)
If there should be a greater
future
reliance on
imported
foods with a
concurrent decrease in consumption of local foods, the estimated doses would
be lower. Also, the BNL diets applied to most atolls are considered to be upper
limits for current lifestyles with a good probability that a typical, average diet
would be less than that listed in the BNL report.-7
The doses to children have been calculated previously and are always less than the
estimated adult doses. 459
That is, the 30- and 50-y integral doses starting at birth
through 30 or 50 y are less than similar doses calculated for an adult.
If the dietary
intake of 1376, for children is equal to or less than that for adults, the dose to children
will never exceed that to the adult.
41 The data from both the MLSC and BNL diet
surveys indicate that the consumption of key local food items for ages | to 18 are less
than those for adults, and therefore the radionuclide intake would also be less.
54
ArhtydrakeRAHLA6 LS eeeS
(3)