the external dose assessment,
pandanus fruit and breadfruit.
is based
For living
upon the unmodified conditions for the
pattern III, for example, the total
village island.
terrestrial bone dose is 75*rem, of which
The largest contribution
to the whole-body and bone doses comes
74% is derived from the intake of bread-
from the terrestrial food chain, the ex-
fruit and pandanus.
ternal dose pathway is the next highest
however, that the large contribution tc
contributor,
the bone dose via these fruits occurs only
and the marine food chain
It is important to note,
and inhalation pathway contribute the
when they are grown on northern islands,
least.” The relative contributions of each
Pandanus and breadfruit grown on the less
diet component to the terrestrial pathway
contaminated southern islands lead to
dose is shown in Tables 242 and 243,
much lower dose commitments.
Table 245 shows the 30-yr integral
In general, living on JANET, visiting
northern islands, and maintaining
dose for the six living patterns for the
agriculture on northern islands (living
modified soil condition, i.e., where the
patterns III, V, and VI) lead to signifi-
village area has 5 cm of gravel and the
cantly higher doses than if the village and
village island is plowed.
agriculture are located on islands in the
shows the 5-, 10-, 30-, and 70-yr dose
southern half of the Atoll (living pattern
estimates for the same conditions.
I).
Doses for these same patterns have
heen calenlated for &
10)
Table 246
Table 247 shows the additional effect
and 70 vr and
on the 30-yr integral dose of limiting
growth of pandanus, breadfruit, coconut,
are shown in Table 244,
and tacca to the southern islands, while
The most significant contribution via
the terrestrial food chain is the dose to
Table 248 shows the effect of limiting all
bone resulting from 905» uptake via
terrestrial foods to the southern islands.
The effect of the combination of these preventive measures reduces the dose for
“As indicated earlier, these dose calculations assume that the Enewetak people will continue their current practice of
living pattern III from 11 rem to 1.9 rem
for whole body and from 80 to 4.7 rem
using catchment rain water for drinking
and that the underground lens water sup-
for bone.
A comparison of the 30-yr integral dose
ply will not be a part of their diet. An
indication of doses that are to be expected
from lens water may be obtained from
for living patterns I and III relative to the
average United States externa] background
four water samples taken on JANET in
July 1971. These samples, two each
from each of two 2,5-m-deep holes about
100 m from the lagoon shore, gave aver-
dose over 30 yr is shown in Table 249.
Plutonium isotopes, because of their
age concentrations of 130 pCi/liter for
90Sr, and 400 pCi/liter for 138%Ccs, 239py
long half-lives, will still be present
<0.03, and 17 pCi/liter) but, for our current purpose, we will assume an average
at the Atoll have decayed away; therefore,
concentrations were scattered (<0.03, 21,
value of 20 pCi/liter.
when the other major isotopes observed
Tables 250 and 251 are included to show
Using these concentrations, and
the predicted doses from plutonium to
assuming an average daily intake of
100 m1 of lens water, the resulting 30-yr
doses would be 0.83 rem due to °9Sr,
0.019 rem due to !8?Csg, and 0.00082 rem
due to 239pu,
the three major receptor organs (lung,
liver,
and bone) via the three relevant
exposure pathways.
II-60