-23-
surface contamination accounts for the higher activity
eidusl
gid:
the external plant
parts.
tions through and
Levels of activity in successive collec
expectation
Soluding December 1954 drop in accordance with the
4 mixed fission products.
The January 1955 land plant col-
Bections, however, show & trend toward inereasing activity
BBvels (Figure 9).
This could be due to @ sampling error, but
| Bght also be @ reflection of greater availability of the fission
hoducts to the plants associated with more rainfall during
fate December to January.
eA ipris te SEEee
The values for arrowroot collected on Rongelap Island in
uary 1955 fell within the range of values for arrowroot from
whe northern islands.
Mepths of 10
ij
ap Islends.
The same is true of algae collected at
to 25 fathoms in the vicinity of Kabelle and RongeHowever, the maximum activity levels found in
fal imeda Sp. and Caulerpa sp. from Rongelap are higher by a
@ector of about two than the maximum levels found in the seme
BBpecics collected at Kabelle.
4
It appears likely then that al-
; ough maximum fallout occurred at the north end of the atoll,
generadioactive material 1s being redistributed throughout the
toll, at least in the deeper waters.
,
Decay rates of five individual samples of algae and land
pants collected in July and December 1954 indicate half-lives
Zing from 160 - 210 days during the period from December 1954
. April 1955. A sample of coconut milk collected at Kabelle
pSland in December 1954, however, shows a half-life of approxi-
. ‘ely three years.
The slopes of the decay curves of land and
att
Ww