Table 1.
Per Cent Abundance and Relative Maximum Permissible
Concentration of Fallout Radioisotopes of Biological Interest
Fission
Per cent abundance at:1)
One
One
One
Ten
week
month
gr89
2.1
6.7
2.7
¥90
y%l
--2.4
--;
1.8
3.9
products
gr90
7-7
---
year
1.8
zZr95
Nb995
Rul06
Rh 106
ji31
2.5
------6.3
8.2
4.1
----3.7
7.30
15.0
2.4
2.4
---
Bal3?m
Bal40
Lal40
Cel44
pri44
Pm!47
-~8.8
9.4
-------
--10.8
12.5
2.0
2.0
---
1.5
----26.5
26.5
5.7
Cg 137
---
---
1.5
Relative
MPC
years
Half life?)
---
50 days
100
21.8
---
64 hours:
58 days
200
300
21.8
28 years
values?)
1
---=-------
65
35
365
2
8
days
days
days
hours
days
600
1, 000
100
*
20
18.2
--=>
----15.8
3
13
40
285
17
950
mins.
days
hours
days
mins.
days
*
300
200
100
*
2, 000
18.2
27 years
200
Non-fission
roducts
Mn>4
290 days
1, 000
Feo
950 days
8, 000
Coo?
270 days
5, 000
CoS0
zn65
1900 days
245 days
500
1, 000
Feo
Co
45 days
71 days
1) Hunter and Ballou (1951)
2) Strominger, Hollander and Seaborg (1958)
3) MPC values relative to Sr99; based upon values from
*
Handbook 69 for which MPC for Sr99 ig 1076 ye/cc
A short-lived daughter for which hazard is negligible
in comparison to hazard for parent
600
1, 000