amounts.
In general,
csi37 accounts
for 90 per cent or more
of the radioactivity in the land plants and sr?9 for the
remainder.
This is unlike the situation usually found on con-
tinental soils and is a consequence of the low potassium content of Rongelap
soil.
Amendments of potassium to
soil reduce the uptake of csi37 by plants
press),
Rongelap
(Walker et al.,
in
and affect the distribution of csi37 within the plant.
There are,
of course,
differences between plant species and
Plant parts with respect to the relative amounts of potassium
and strontium.
For example,
as compared with Pandanus
copra contains very little sr 20
fruit,
and the basal leaves of vari-
ous plants contain more sr?° relative to cst37 than do the
terminal leaves.
This variation is related to differences in
mobility between Cs - K and Sr - Ca.
The rats contain Cs 137 and
90
Sr°~,
reflecting the radio-
nuclides present in the plants on which they feed.
The coconut
crab and the land hermit crab Coenobita perlatus contain the
same isotopes but concentrate sr? ,as has been reported for
Coenobita from Eniwetok Atoll
( Held,
1960).
The occurrence of radionuclides in man at Rongelap has
been summarized by Cohn et al.
were Csl37 ana sr?9,
(1960).
In 1958 these nuclides
coming from the food plants,
coming to man from marine products.
and gn©?