Section 2.3, the Bikini wells do not meet the practical
standard, whereas
wells on Eneu do.
Ground-water consumption makes a small
body
dose.
If
calculated
on
contribution to the whole
the unrealistically
high
consumption
of
2 liters per day (6), it would amount to less than 5 percent of the total
dose for Eneu or Bikini.
ground-water
However, the Lawrence
consumption
to
average
about
Livermore team estimates
0.25
liter
per
day
over
the
course of a year (6).
3.4
Permissible Soil Specific-Activity
For the very low concentrations of cesium in atoll
soil, it may
be assumed that uptake by food plants -- and thus subsequent human
--, will
be proportional
to soil
concentration
(23N).
intake
Turning the problem
around, we may say that having found the estimated dose to be six times too
high (30.8 vs. 5 rem), the island's rooting-zone specific-activity (0-40 cm
depth) should be reduced to one-sixth of the present level.
On
this
basis,
the
liminal
specific-activity
of
the
island's
rooting zone -- that mean value (0-40 cm depth) not to be exceeded -- can
be calculated for Bikini as follows:
(5 rem/30.8 rem) x 28.6 pCi/g
where 5 rem is
current
mean
=
4.6 pCi/g (liminal value),
the standard and 30.8 rem is the dose associated with the
specific-activity
of
the
rooting
zone,
28.6
pCi/g
(island
distributed mean).
Spontaneous
decay of cesium-137 will
reduce
activity of Bikini's rooting zone to the liminal
exactly).
value
the mean
in
specific-
80 years
Or the liminal value can be produced more quickly by removing 30
cm (28 cm, exactly) of the top layer of soil (Section 2.2, Figure 4).
000025
(79.1
26