Estimation of depth of basal cell layer of skin for radiation protection

The depth of basal cell layer of the epidermis is currently taken to be 70 μm. In order to re-evaluate this from the standpoint of radiation protection, an experimental study was carried out to estimate the depth of the basal cell layer. One hundred and thirty-five skin samples from 41 body sites of 19 adult subjects were examined. The results showed that the depth did not differ with age or sex, but had a significant correlation with body site. A reasonable estimate of the depths was as follows: 40 μm for the head and trunk, 50 μm for the arms and legs, 150 μm for the dorsal and side surface of the hands and feet, and 300 μm for the volar surface of the hands and feet. From these results it is proposed that the value of 70μm should be replaced by a value of 40 μm. (author)