page 564
Radicecology
—
peen made concerning the levels of radioactive
tron and cobalt in areas contaminated by reactor
effluents, primarily because relatively small
amounts of these radionuclides are produced.
Krumholz and Foster (1957) reported the concentration factors for iron-59 in several organisms collected in the Columbia River. The concentration factors were as follows:
phytoplankton
filamentous algae
insect larvae
fish
200, 000,
106,000,
100,000, and
10,000.
Table 2.
The invariable primary constituents of
living matter according to percentage of
body weight (Webb and Fearon, 1937; Mason,
1958) .
Primary
(1 to
60 per cent)
Hydrogen
Carbon
Nitrogen
Oxygen
Phosphorus
Secondary
Microconstituents
( 0.05 to
1 per cent)
(less than
0.05 per cent)
Sodium
Magnesium
Suifur
Chlorine
Calcium
Boran
Iron
Silicon
Manganese
Copper
Iodine
Cobalt
Molybdenum
Zinc
The primary producers, the phytoplankton and
filamentous algae, concentrated radioiron to a
high degree. The concentration factor for zooplankton was not reported but probably was about
the same as that of the primary producers since
the concentration factor for insect larvae was
of the same order of magnitude, In the fish, however, which accumulate radionuclides principally
by ingestion,
amount of isotope dilution in sea water for
radioisotopes of biologically important elements
is as yollows (cobalt isotope dilution evaluated
to one}:
the concentration factor was about
one-tenth that of the other organisms.
Several observations have been made in the
tropical oceanic and terrestrial areas of the
Central Pacific Ocean regarding the amounts of
Primary
Hydrogen
2.2 x 10°
Carbon
5.6 x 105
Phosphorus 1,4 x 10°
.
Microconstituents
Secondary
Sodium
Sulfur
Chlorine
Calcium
2.1x
1.8 x
3.8 x
8.0 x
106
10,
10,
10°
radioactive iron and cobalt within organisms and
their environments and have been reviewed by
Lowman (1960), In these studies the levels of
radioactivity in solution, in colloidal form, and
associated with small particles in sea water have
been compared with the radioactivity in plankton,
sessile invertebrates, filter feeding and carnivorous fishes, and birds whose source of food is
marine organisms,
On land the amount of radio-
activity have been measured in soils, plants,
and
herbivorous animals, In addition, analyses of
soils under the nesting areas of birds have been
made in which the radionuclide content has been
altered by the excrement of the birds which feed
upon marine organisms.
Radioisotopes of all of the microconstituents of biological material are subject to less
isotope dilution in sea water than are the primary and secondary constituents,
Thus, for equal
amounts of radionuclides added to sea water an
organism would have to concentrate 2,2 x 198
times as much stable hydrogen and 8.0 x 10% times
as much stable calcium as it weuld stable cobalt
to contain an equal amount of each of the three
radionuclides,
Marine organisms do exhibit the ability to
concentrate many elements from sea water (Donald-
gon et al., 1956; Boroughs et al.., 1957; Krumholz
et al., 1957; Lowman et al., 1957, 1959; Seymour
et al., 1957; Lowman 1958; Palumbo et al., 1959),
Iron and cobalt are microconstituents of
living material and, although present in small
anuounts, are important in the normal metabolism
of most organisms (Table 2). Ail of the micro-
and it is usually assumed that the organisms rapid-
_constituents except boron and silicon have high
specific gravities and atomic numbers in comparison with the primary and secondary constituents.
In sea water, iron and cobalt are also mi-
croconstituents, contributing only 0.000001 and
0.00000005 percent respectively of the total
mass. The radioactive forms of these elements
introduced in fallout are therefore subject to
limited isotope dilution by the corresponding
stable element in the water.
A comparison of the
Table 3,
Manganese
4,0
Iron
20.0
Cobalt
1.0
Copper
6.0
Zinc
20.0
Molybdenum 20.0
ly acquire a major fraction of the radioisotopes
of these elements introduced in fallout. At the
Eniwetok Proving Ground this does not occur,
probably as a result of the plankton contributing
only one part per million of the total volume of
sea water plus organisms, Although plankton exhibit high concentration factors for some elements
the relatively small amount of these organisms in
the tropical waters resulted in their containing
only 1/10,000 of the total radioactivity at one
week and 1/30,000 at six weeks after the water in
Percent of total radioactivity in sea water and plankton contributed by fission products and neutroninduced radionuclides at approximate times of 48 hourg, one week and six weeks (Knapp, 1960; Lowman,
1960).
The percents of total are underlined.
Less than
48 hours
Water
Plankton
Molybdenum - 99, Technetium - 99m
Cerium ~ 141,144, Praesodymium - 141,144
Ruthenium - 103,105,106, Rhodium - 103,105,106
Barium - 140, Lanthanum - 140
Tellurium - 132, Iodine - 132
Zirconium - 95, Niobium - 95
Strontium ~- 89,90
Cesium — 137
Neptunium - 239
Uranium — 237
Cobalt - 57,58,60
Zine
Tron -- 65
55,59
Wanganese
aes - 54
5.9
12.0
Greater than
One week
Water
Plankton
5.0
0
Six weeks
Water
Plankton
0.02
0.83
2.1
2.6
6.2
0.38
0,30
0.01
54.0
24.0
0.02
3.0
3.0
2.0
8.0
1.0
0
0
69.0
3.0
0
2.1
2.2
6.8
5.6
1.0
0.76
0.05
33.0
43.0
0.05
0
5.0
23.0
0
6.0
0
0
2.0
2.0
43.0
20.0
16.0
18.0
0.05
18.0
8.2
0.08
0.02
18.0
0.87
0.02
)
0.05
16.0
0.93
0.02
trace
0
0
0.05
0.01
3.0
0
0
5.0
1.4
0
0
20.0
0
0
0
0
24.0
0.84
25.0
0.12
0.6
24,0