Table 1.
Per Cent
Abundance
and Relative
Maximum
Permissible
Concentration of Fallout Radioisotopes of Biological Interest
Per cent abundanceat: }
)
Fission
One
One
One
Ten
products
week
month
year
years
sr89
2.1
$r90
“--
¥99
mee
y?!
2.4
zr95
6.7
Relative
MPC
Half lite?
values?!
2.7
---
50 days
calial
1.8
21.8
28 years
1
wee
1.8
21.8
64 hours
200
7.6
3.9
---
58 days
300
2.5
8.2
7.300
---
65 days
600
Nb95
~--
4.1
15.0
---
35 days
1, 000
Ru 106
---
wee
2.4
---
365 days
100
Rh 106
-+-
---
2.4
---
yi3l
6.3
Cai87
ew
ee
1.5
Balsim
.-.-
---
15
i
100
2 hours
*
8 days
20
18.2
27 years
200
18.2
3 mins.
*
1) Hunter and Ballou. (195)
2) Strominger, Hollander and Seaborg (1958)
3) MPC values relative to Sr99: based upon values from
69 for which MPC for Sr?9 ig 1078 ue/ec
*
A short-lived daughter for which hazard is negligible in
comparison to hazard for parent
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