from different islands and of pelagic species from the lagoon during the 8-ye
period.
Concentrations of 137¢s in the muscle tissue of all species of fist
during this period ranged from 7 to 460 pCi/kg wet weight.
The maximum
concentration of !3’cs in flesh, 460 pCi/kg wet weight, was measured in
surgeonfish collected from island B-1 in 1983, and the mean concentration i:
the flesh of all
weight.
reef fish during
the 8-year period
was 113 pCi/kg wet
The computed annual whole-body dose-equivalent rate to individuals
from !37Cs in the fish ingestion food pathway would have been less than 1 mr¢
(assuming a consumption
rate of 200 g of fish
flesh
per day and a
concentration of 113 pCi/kg wet weight).
Between 1977 and 1984, generally higher concentrations of !3’cs were
measured in muscle of reef fish from the northwest quadrant of the atoll (Bto B-5), and the lowest levels were found associated with reef species from
the eastern reef of the atoll.
In 1982, marine fish fillets purchased fron
stores in the Chicago area of the United States, contained 23+2 pCi/kg of
137¢s derived from global fallout.29
Table 7 shows that the mean |
concentrations of !37Cs in fish from islands B-10 to B-23 are now comparabl:
to the fallout levels in the store-purchased fish.
In Table 8 are shown several examples of the different concentration fc
137¢s (pCi/kg wet weight) measured in the muscle tissue of different reef
species collected from the same island during different years.
The mean
concentrations determined for all lagoon species during yearly intervals ar
shown in Table 7.
There does not appear to be any precise trend indicatinc
that the concentrations of !3/Cs in the muscle of these fish have been
changing over the years at some consistent rate.
There also appears to be r
clear trends of consistent differences in concentrations among the differen
reef species simultaneously sampled from the same location (see Appendix).
1978,
for
example,
at
island
B-1,
the highest
concentration among
different reef species was measured in mullet (Crenimugil).
1983 and at B-6 in 1980,
the
At Island B-1
the concentration in surgeonfish exceeded the
measured concentration in mullet and goatfish.
In
1984,
the measured
concentration of !3’c¢s in the muscle tissue of goatfish was larger than th:
concentration measured in any of the pelagic species collected off the islan
however, at B-6 and B-23 in 1978 and at B-6 in 1980, the concentration in
goatfish was lower than the levels detected in pelagic species from the
respective islands.
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