Table II.
Isotope
The Naturally Occurring Radioisotopes in Sea Water
Total activity
Per cent
Radioactivity
in ocean in
of total
in sea water
megacuries 1)
activity
97.1
(MP C),,4)
d/m/ 12)
pc/ ec3)
ucice
736
3x107?
+
«40
480, 000
Rp87
8, 400
1.77
13
6x1079
1073
y238
3, 800
. 80
6
8x107°9
2x1074
Ra226
1, 100
23
2
1978
1077
cl4
270
057
1
5x10710
gx1073
y2s5
110
023
1
"
3x1074
12
003
1
"
03
8
002
I
"
2xi075
H3
Th232
Total
473, 700
100.0
758
3x1077
1)
Revelle (1957)
2)
Disintegrations per minute per liter based upon calculated
value for K49
3)
Microcurtes per cubic centimeter
4)
Maximum permissible concentration for water consumed by man
(Handbook 69, 1959)
*
No value given, hazard negligible