Pathway Analyses
PLUTONIUM CONCENTRATIONS IN THE
INHALATION PATHWAY
The contribution from the inhala~
in the air than expected from worldwide fallout and more than encountered
in New York City during comparable
tion pathway to plutonium concentra-
periods.
tion in urine, especially at Bikini,
resuspension does significantly
is very hard to quantify.
contribute to inhalation’ of plutonium
In addi-
tion to the different activity levels
These data indicate that
at Bikini.
We will show in a follow-
from fallout in the air at Bikini and
ing section that resuspension might
New. York, reSuspension processes that
also contribute to elevated plutonium
contribute airborne plutonium at New
levels in the ingestion pathway at
York and Bikini are very difficult
Bikini.
to assess.
Nevertheless,
it is
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Comparable data on plutonium con-
important to assess these processes
centrations in the air exist only for
in estimating the cumulative exposure
the periods of May 29 to June 2,
to plutonium from inhalation.
1970,° and May 1972.?
Bennett? has recently concluded that
sampling period,
plutonium from resuspended fallout
During the 1970
239,240 Pu
levels in
.surface air were determined at five
at New York presently contributes
locations on Bikini Island and ranged
0.3% and will ultimately contribute
from 60 to 540 aci/m>.°
intake equal to 0.5% of the intake
cencentration at four sites on the
that occurs during the original
island of Eneu (in Bikini Atoll) was
deposition of the fallout debris.
only 40 aCi/m> during a comparable
Data of one of the authors * show that
period. °
the soil plutonium levels on Bikini
function of latitude are the average
Island are, on the average, higher
plutonium concentrations at ground
than plutonium levels from fallout
level at air sampling stations of the
deposited in the United States.”
HASL sampling network,
Visual observations indicate that
The mean air
Plotted in Fig. l as a
June 1970.8
taken during
The concentration-—
the formation of dust clouds or the
latitude profile is simply a con-
resuspension of surface materials by
tinuous curve drawn through the
people or vehicles at Bikini is
availabie data points.
slight, even during very long dry
spells.
However, the available
From this curve, the average
fallout-plutonium concentration
aerosol data show that some locations
expected in ground-level air at the
on Bikini Island have more plutonium
latitude of Bikini Island (11°, 37'
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