Cohn, Robertson, Conard
The presence of Co“? in the soft tissue of clams was noted for the first time
in the 2-vear resurvey (Weiss and Shipman, 19571. The Coaccounted for
the major fraction of the total activity in the clams. The very marked ability of
clams to concentrate Cot selectively was verified in laboratory experiments
(Gong et al. 1957)
Land Animals
Internal radioactive contamination of animals from Rongelap was determained by radiochemical analyses of the tissucs of domestic animals {pigs and
chickens) sacrificed at various times following contamination (Cohn et al,
1955,. The internal contamination resulted from both inhalation and ingestion
of contaminated food, with the latter being the more important route of entry.
The bedy burden of fission products was ‘roughly proportional to the ganima
dose rate on each island. The internally deposited activity in the pigs ving on
Rongelap for } monthafter the detonation was tenfold higher than that of the
human beings who were evacuated within 45 hours. The difference thus refiects
the proionged stay of the ammuals m the contaminated area.
Only a small percentage of the fission products initially present in the environment was readily absorbed from the Jungs and G. 1. tract and retained in
the body of land animals. This G.I. tract activity was contnbuted chiefly by
swatopes of Siort radiological and biological half- life and hmired salubihtv, and
thus thelevcls of activity in thetissues of the body were quite low. At 3 months,
raciochenucal analyses of tissues from Rongclap pigs medicated that Sré", Balse
and the rare carth group constituted 73 per cent of the total internal beta acTapre 3. Rachochemical analvsis of tissues and urine of Rongelap pigs exposed tofallout
from the March 1, 1954 nuclear detonation? (from Cohn et al. 1955}
Beta activity d/m/total sample % 10°°
Skeleton ¢total) oo. ee |
Lungs (alveolar) ..
Storahy oo cece ceecee cescesse veseseeerneente cas
Smal] intestine ooo. cc eee neo
Large intestine oo eee
Lived occ ce cesses cece ae
RIGNOYoe ee cnn cee ce
Remaining Carcass a. eco
Gross
activity
Sr*
OES
(100°; )
1.3
3.380
(62% J
0.24
16
0.26
25
0.73
29
3.2
4355
0.47
0.18
14
5.0
Ba'*”
595
(6.8%}
0.22
0.62
0.69
2.8
0.27
0.30
Rare earths
850
(9.7% }
0.57
0.40
0.69
4.0
3.9
0.6]
ThvP01d dOS8€ oes ceceee eee 200-150 rep (estimated from early analvsis of urine)
Total external gamma dOS€ wc.
3301
Internal beta activity
Ce,
+ ue
*Nalues are the average of two voung adult pigs which were analyzed 3 months
after detonation.
316