viscera.
If the internal, body burdens of transuranic nuclides are accumulated
by the fish through the gut, then it could be concluded that in most cases
there is a discrimination against @4!Am relative to 239+240py in different
tissues.
The radionuclides 242cm, 243cm, and 244cm have been detected in some fish
tissues from Bikini. Concentrations of 43cm and 244cm are a few percent of
the 239+240py concentrations and 242cm is less than 1% of the 239+240py levels
in the entire fish.
25 years
after
The detection of 242cm (tj/2 = 163 d), approximately
the end of testing,
indicat®s the presence of a parent
radionuclide, 242MAm, in the environment.
OTHER RADIONUCLIDES IN FISH
Concentrations of '13mMcg and naturally occurring 2!0pu, 210p0, and 2108;
determined in fish samples are listed in the Appendix.
Discussions of the
concentrations and significance of these radionuclides at Bikini Atol]
have
been presented in the literature®-8 and will not be repeated here.
RADIONUCLIDES IN INVERTEBRATES
Edible species of clams and a few other invertebrates
were
collected by hand (free diving) in shallow areas of the lagoon.
sometimes
Collections
for radionuclide analyses were terminated in 1980 for fear of depleting this
valuable food resource at the atoll].
Radiological concentration data from
analysis of these few samples are included here for reference.
The clams were weighed, measured (total length), and dissected.
muscles, mantle plus siphon, kidney,
Adductor
and remaining viscera that included
©
gills, gonad, stomach, intestine and contents, crystalline style, heart, and
nervous system were removed for analysis.
Tissue samples were dried in ovens
at 90°C to constant dry weight and dry ashed in muffle furnaces at 450°C for
approximately
~ invertebrates
72
were
hours.
Radionuclide
determined
by
the
concentrations
same
procedures
in
tissues
used
to
of
measure
concentrations in fish tissues (see Sample Processing and Analysis, page 7).
Collection
information
and
radionuclide
concentrations
are
shown
in
Tables A-15 and A-16 of the Appendix.
Too few samples were collected and analyzed to develop trends or
meaningful relationships with the concentration data. However, it is noted
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