ctl RA, BEMonter GrekBURT, PORE
tenn feltineeerere
for
This observation is in
this group of radioelements.
agreement with the findings of the Taney survey (10)
which the major fission products
be Celth_pyl44 ,
in
in plankton were found to
However, & gamma spectrum curve made
on
these plankton samples November 1957 by the present author
revealed an appreciable amount of Co®0,
Zr95-nb95 were not
found in the Taney samples because of the short half life of
zr?> (65a).
In the case of the non-fisstion-product radioelements,
zinc,
cobalt,
and iron were present in the plankton (based
on an average of the five samples)
in approximately equal
amounts at about 24 per cent each and manganese at a level
of less than one per cent of the other three elements.
of these elements,
initially in the
from fallout in the sea,
All
would exist
insoluble form.
Limited data from both control experiments (4) and
field observations (21) suggest that the major route for uptake of fallout radioisotopes by marine animals is through
the ingestion of radioactive particles.
also that,
Chipman (5) noted
in addition to the filter feeding animals,
two
species of algae were able to concentrate Cel44 several
thousand times over the levels in the water although the
radioisotope was in the particulate form.
is
The present work
in agreement with the postulate that the major source of
radioactive elements from fallout to marine zooplankton is
through the uptake of particulate material.
The uptake may
jo
—
rsons wun"
eee Kawabata, pe
-19-