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TABLE 3
EXPOSURE RATES IN AIR DUE TO *°K, 7°°u, and 797th IN THE SOIL (ur/hr)
Detector
Exposure
Height
(meters)
Rate* per
.
0
1
3
5
10
30
100
300
1% *°K
% Decrease
from 0
Rate* per
Meter Value
1 ppm *7°ut
1.68
1.65
(1.71T)
1.60
1.56
1.47
1.22
0.72
0.19
*1% *°K = .0586 dis/cm*®,
dis/om*®,
Exposure
soil density,
0
2
5
7
13
27
57
89
% Decrease
from 0
Meter Value
. 667
. 654
(.76T)
.635
.618
. 583
»476
.274
. 068
1 ppm 7°° = .0198 dis/cm?,
p = 1.6 gm/cm’*.
0
2
5
7
13
29
59
90
Exposure
Rate* per
1 ppm 7°"
% Decrease
from 0
Meter value
.314
. 307
(.36T)
. 298
. 290
.274
.226
. 133
. 036
0
2
5
8
13
23
58
89
1 ppm 7°*Th = 6.57 x 104
tPreviously reported values‘??,
tExposure rate due to radon daughters in the atmosphere has been neglected but
should not amount to more than a few percent of the total exposure rate even
close to the interface‘!**?,