Table If.
Isotope
The Naturally Occurring Radioisotopes inSea Water
Total activity
Per cent
Radioactivity
in ocean in
of total
in sea water
megacuries 1)
activity
97.1
(MP C)y4)
d/m/ 12)
pefec?)
ucice
736
3x1077
*
«40
460, 000
Rb 87
8, 400
1.77
13
6x10~2
1073
238
3, 800
. 80
6
8x1079
2x1074
Ra226
1, 100
23
2
1078
1077
5x10710
ci4
270
057
i
235
110
023
1
12
003
1
"
.03
8
002
i
"
2x1075
HS
Th232
Total
473, 700
100.0
758
gx1073
3x1074
3x1077
1)
Revelle (1957)
2)
Disintegrations per minute per liter based upon calculated
value for K40
3)
Microcuries per cubic centimeter
4)
Maximum permissible concentration for water consumed by man
(Handbook 69, 1959)
*
No value given, hazard negligible