21
SUMMARY
The concepts on the uptake and concentration of fallout by
marine organisms that were presented at the 1957 Hearings are
basically unchanged.
The greatest emphasis of recent studies has
been to identify all of the radioisotopes in the samples.
The following observations in an area of local fallout,
the
Eniwetok Test Site, have been made:
(1)
and Ce
144
present,
.
Cs
137
.
:
:
.
, only the latter is found in marine organisms.
Sr
90
occurs at low levels); by contrast Cs
.
.
are found in land forms while Ce
(2)
‘
Of the three long-lived fission products,
144
,
or
90
(If
and Sr
90
.
generally is not.
Of the non-fission products radioisotopes of iron,
zinc,
cobalt and manganese were predominant in marine animals but were
much less abundant in marine plants,
land plants and land animals.
Radiostrontium as stratospheric or possibly intermediate
fallout has been measured in the Atlantic Ocean.
The data so far
available indicates an amount in surface water greater than predicted, but the significance of the difference is questionable
because of the limited number of samples.
The program at Rongelap Atoll has been enlarged to include
basic studies of mineral transport and metabolism in addition to
radiation monitoring.