New values for epidermal thickness and their importance.

Abstract The thickness of the epidermis on 214 skin samples from 188 volunteers has been measured by a new technique which involves a weight determination. The results do not depend on the natural elasticity of the skin and therefore differ significantly from those of earlier conventional methods of measurement where no correction is made for shrinkage. It has been shown that epidermal thickness is not dependent on age (between 15 and 89 yr) or sex but varies significantly with body site. For radiological protection purposes it is appropriate to replace the value of 7mg/cm2, currently used for minimal epidermal thickness on all body sites, by a value of 4 mg/cm2 for average epidermal thickness. Where it is justifiable to distinguish between body sites three different regions could be considered having average epidermal thicknesses of 4, 8 and 40 mg/cm2. Design parameters are suggested for personal dosimeters appropriate for use on each of these three areas.