RESULTS AND DISCUSSION
awit
Me
ye
el
rays
me
of the Marshall Islands contaminated by the 1954 nuclear detonation
were detected in February 1955, The residual radioactive contamination’
expressed in terms of gross beta and gamma activity of the tissues of
ibe
Te
_
\a
The complete
|
per unit weight of individual fish and marine invertebrates from the same
area as wellas from different geographic locations. Part of this variation may be attributed to differences in feeding habits. However, no
correlation hetween the level of radioactivity and the eating habits of
the fish (carnivorous, herbivorous, omnivorous) could be ascertained,
nay
ane,
fe
En
bea
Of course, currents and Iccalized concertrations of radionuclides may
also play a role in determining concentrations of residual activity in the
lagoon fish. In Table 4.1 an average value for the analysis of the fish in
each locality is reported.
.
Fish ard invertebrates caught in the northern section of the Rongelap
Lagoon had the same level of beta activity but twice the gammaactivity
of fish from the southern section of the lagoon (Table 4.1). The ratio
of activity in marine invertebrates between the north and south ends of
the lagoon was considerably lower than that observed one year following
the detonation. This finding suggests a redistribution of activity from
the higher concentralion originally existing in the northern end of the
lagoon. The pattern of the 1954 fallout was such that the activity on the
&
%
Ty
owes
CO ete AR endmeg
en
-.
aa
a
we
|
Roan ee
a
vera ayaa+
F
85 fish and marine invertebrates is presented in Table 4.1.
data appear in Table A.3, Appendix.
Considerable variation was observed in the concentration of activity
ea
mn
tess
ore
Readily detectable levels of radioactivity in land and marine animals
mn
ve
a
northernmost islands w2s tenfold higher than on Rongelap Island, at the
southern end of the atoll.
ii
The internally deposited activity in the fish was only very roughly pro-
1
portional to the external radiation dose over that island,
MT
'
Ss
Bi
ae
'
\
i
4
=
tpi
Crabs and clams were found to have a residual concentration of beta-
emitting radionuclides of about the same levelas fish from the corresponding locality (iable 4.1}. This is in contrast to the larger differences
noted between crabs and clams as compared to fish at one year post~
detonation,
Snails from Ceofer had ccrsiderably higher concestrations of activity
than fish from tie scarse jecality, as was noted in the one-year resuivey.
The higher levc! of activity of the snails may be related to their habit of
feeding on the sottu.n o: the lugoon where higher concentrations of radionuclides were found, The relatively lower values of activity in clams is
i pe
ae
ABLE|
eeORE
7°
FE
ae: Ld
BO
SEB
ge
RORY
fe
rye
TanelnagS ns me plageta dian! eal gee ge oat
poe eeae
,
Pas
2
?
Pt Rr
eae aepe me eete
ser
eee
Ee
een to
roger
Sa
pas ee
ie TeRTTse
enn Frenrocepee
. oo
.
ot
. or ee
.
Pt
ee
aoa
chia to,
’
te
—g Oe
cement
"
——
Bape ge AO ie de
ee
: