is the lower legs.
One report estimates a beta to gamma dose rate ratio of about 75
to 1 at 10 centimeters above the ground.*
Under Criteria I it was
recommended that consideration be given to evacuation when the gamma dose
rate reading at three feet was, for example, about 6.2 r/hr at HY3 hours.
Roughly, this would correspond to about 575 reps/hr of beta at 10 cenOf course, this activity decays and also it is presumed that
personnel would be sent indoors, at least for a few hours,
On the other
hand, it strongly suggests that biologically significant doses may be
delivered to the feet if not protected.
Skin lesions were frequent on
the bare feet of the natives evacuated during CASTLE.
This probably was
a combination of beta dose from material on the ground and from that
scuffed up over the bare feet and then clinging to the skin.
amt ee ee
timeters.
(No lesions
from such high beta doses as discussed here.
There is still no guarantee
that beta radiation from material on the ground will not deliver signif-
icant biological doses to the ankles and perhaps lower legs, after per=
sonnel are released from staying indoors.
For example, if the beta dose
at 10 centimeters above the ground is 575 reps/hr at H43 hours, it would
be about 250 reps/hr three hours later and 160 reps/hr six hours later.
One further possibility is the accumlation of radioactive material
around the ankles and lower legs resulting from normal walking about the
area.
This is discussed under Criteria III.
*AD-95(H). An E
e_of the R
ve Haz
B
Gar
Fission Condit, R. I., Dyson, J. P., and Lumb,
We A. S, NRDL 1949 (UNCLASSIFIED)
Ree
ba
.
thoy
tale
ee
=
compared to open sandals) would afford adequate protection to the feet
ae CR eineee, Ml en,
.
a,
It would be expected that normal closed-type footwear (as
1 a kat pn agp,I
epidermis.)
Spe necite at
were observed on the bottom of the feet, undoubtedly due to the thick