[Contamination of human skin by radionuclides]

Insight into the mechanisms of contamination is a necessary prerequisite for efficient and meaningful decontamination. The incorporation of anorganic ions into human skin has been studied with aqueous solutions of radionuclides. Within 30 min of wetting about 1 microliter fluid per cm2 skin area penetrates into the capillary spaces of the horny layer, promoted by surface-active properties of the sebaceous lipids. Adsorption onto horny layer constituents is especially important for polyvalent cations. In general it is dependent on pH and on the ionic charge. For all substances in aqueous solution the structure of the horny layer causes a nearly exponential decay of concentration with depth of penetration (about 100:1 across the horny layer at 1 mg keratin/cm2 skin area). This is the reason for the very low penetration rates. The results may be used to establish some rules for skin decontamination.