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