inhalation at Bikini Island also
of plutonium to a person's urine
exceeds thap in New York.
during the course of a year.
The transfer coefficient across
An inhalation pathway analysis
based on a mass~loading concept
the gut into the blood is assumed to
similar to the one used for the
be 3 x 107° for ingested plutonium. ©°
Enewetak Atoll dose assessment” also
At Bikini this would mean that
indicates potentially higher intake
1.54 x 107°
at Bikini by inhalation.
to the blood.
Using a
pCi would be transferred
Of this amount,
mass loading of 100 ug/m> as in the
approximately gylo st? or 1.2
Enewetak assessment; an average, 0-
x 10°? pCi would be transferred to
to 5~cm concentration of plutonium
the urine.
in Bikini soil of approximately
that at Bikini the ingestion pathway
9 pCi/g;" and a breathing rate of
contributes more than the inhalation
20 m>/day; we find the annual intake
pathway to plutonium in the urine of
via inhalation would be 6.6 pCi,
man.
compared with the estimate of 0.2 pCi
based on aerosol measurements.
.
.
16
Inhalation experiments
and dose
We find from this analysis
In New York,
the contribution of
ingestion to the total level of
plutonium in urine (1.6 pCi x 3
modelg>?t°>4? indicate that approxi-
x 1072 x 0.08 = 3.8 x 107° pci) is
mately 0.1% of the activity inhaled
negligible compared to the contribu-
will be excreted in the urine.
tion of the inhalation route.
If.
There-
we assume that a person's annual
fore the estimated total annual plu-
intake via inhalation'is 0.2 pCi in
tonium in urine would be 2 x 10°
both Bikini and New York, inhalation
for New York residents and 2 x 10.
would contribute only 2 x 1074 pci
41.2107 =21.4 x 1077 pCi for
Table 6.
pCi
4
Comparison of estimated annual intakes of plutonium at Bikini with
those at New York.
,
Pathway
Est. annual intake, pCi/yr
Bikini
New York
Inhalation
20.2
Drinking water”
8.7
Terrestrial foods
21.9
Marine foods
a.
4
Cistern water only.
482
Ratio of intakes,
Bikini/New York
0.2
ol
0.13
58
1.4
i5
0.024
2x 10 4
Any use of ground water would increase this estimate.
-12?-
6032