-55-
Fe-> and zn°5 were the principal radioactive constituents, with
mn>4, Cool, C058, and C9°0 contributing the remainder of the
activity.
6.
In fish liver samples collected at Belle Island, Eni-
wetok Atoll, May and June, 1954, Fe?” accounted for 95.3 per
cent and gn©5 3.1 per cent of the total activity,
vin > Co?! ,
and 600° also were detected.
7.
The pattern of distribution of the transition elements
manganese, iron, cobalt, and zine in the plants and animals at
the Pacific Proving Ground is as follows.
In general, they are
present in the sea and not on the land, in marine animals and
not in marine plants,
Few or none of the radioactive transition
elements are present in island soil, in plants growing in the
soil,
or in the herbivorous field rats
(Rattus exulans).
How-
ever, in the plankton, the marine invertebrate filter feeders
and omnivores, and in the fishes, the above named isotopes are
present and may contribute up to 10C per cent of the total
radioactivity.