nended that consideration be given to evacuation when the gama dose rate
reading at three feet was, for example, about 6.2 r/br at H¢} hours.
Roughly, this would eorrespond to about 460 reps/hr of beta at 10 centimeters.
Of course, this setivity decays and also it is preaumad that
personnel would be sent indoors, at least for a few hours,
On the other
hand, it strongly suggests that biolegically 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 souffed
up over the bare feet and then
oalinging to the skin.
(No lesions vere
observed on the bottos of the fest, undoubtedly due to the thick epidermis 4 ante 7
t: the pronce oy trot tee wertivei a dust ctik to tet fKhin Hit vould ly)
It would be expected that normal
closed-type footwear (ss compared to
open sandals) would afford adequate protection to the feet from sueh high
beta doses as disoussed here.
There is still no guarantees that beta
radiation from material on the ground will not deliver significant
biological doses to the ankles and perhaps lover legs, efterpwcsonnel
are released from staying indoors.
For example, if the beta dose at 10
eentizeters above the ground is 460 reps/hr at H¥3 hours, it would be
about 190 repghr three hours later end 120 reps/hr six hours later.
One further possibility is the accumlation of redicactive naterial
around the ankles and lower legs resulting frou normal walking about the
area,
This is discussed under Felicy III.