The estimated daily loss of trace elements from normal skin by desquamation.

The content of 21 elements (As, Au, Br, Ca, Cd, Co, Cr, Cs, Cu, Fe, Hg, K, La, Mo, P, Rb, Sb, Sc, Se, W and Zn) in normal epidermis has been determined with the aid of neutron activation analysis. The dermal loss of these elements via desquamation has been calculated in view of its possible importance in balance studies. For the bulk elements Ca, K and P, the calculated daily loss is considered to be negligible. For some of the trace elements, however, the loss may be appreciable. The daily loss of Fe by desquamation may be as much as one fourth of the daily urinary iron excretion; the corresponding fraction for Co, Cu, and Zn is one tenth.