instead of the annual 3.65 pCi com-
the inhalation pathway.
puted from the reported data.”
tonium concentrations reported for
There
If the plu-
would, of course, be an additional
urine samples from New York are
contribution to urine plutonium levels
accepted, the data suggest that the
due to transport from deep-lung and
parameters for transfer of inhaled
lymph-node burdens of previous inhala-
plutonium to blood must be consider-
tion exposure.
ably higher than those presently
However,
the magnitude
of this contribution should be similar
assumed.
to that previously estimated for
the percentage transferred from the
New York and would therefore lead to
upper respiratory tract to the blood
total annual urine levels of approxi-
and in the percentage transferred
mately 0.015 pCi.
from the blood to the urine that are
The reported urine
However,
increases in both
concentrations indicate an annual
reasonable for physiological function
urine level of 3.65 pCi.
and chemical transport still cannot
If we
accept these reported urine con-
account for 204 of the total annual
centrations for Bikini,
intake appearing in the urine.
then it would
Be-
seem that the transfer coefficient
cause of this seemingly large fraction
across the gut for plutonium incor-
of the total intake appearing in the
porated in food products must be much
urine,
higher than 3 x 107°.
if this human data indicates that
However,
the New York data indicate
it is difficult
to evaluate
transfer to urine is greater for human
that the major contribution to the
populations than previously assumed
plutonium urine concentrations is via
from animal studies.
Summary
Bikini Atoll may be the only global
Bikini population is correct, and the
source of data on humans where intake
estimated dietary intakes are reason-
via ingestion is thought to contribute
able, it appears that the transfer
the major fraction of plutonium body
across the gut wall of plutonium
burden.
incorporated into food products is
It is possibly the best
greater than previously expected.
available source of data for evaluating the transfer of plutonium
The New York data, where the major
across the gut wall after being
intake is via the inhalation. pathway,
incorporated into biological systems.
if accepted as reported also lead to.
If the plutonium urine data for the
altered conclusions regarding the
-15-
ee 5010235