Is human hair a dosimeter for endogenous zinc and other trace elements?

This work incorporates an assessment of the potential of human hair to monitor ingestion of trace elements from the environment. Included is a report of a study of Zn levels in the facial hair of one of the authors, who was dosed with ZnSO4. Daily doses increasing from 100 to 300 mg Zn were taken for 57 days. Analysis was by differential pulse anodic stripping voltammetry. No significant increase in beard Zn was found. Cd, Pb and Cu were measured simultaneously. Studies of dosing with other elements are reviewed and a generalized pool model for the deposition of ingested trace elements in hair is presented. It is suggested that the concept of hair as a monitor of endogenous elements is a simplistic one which is better modified by the pool model, the precise form of which varies with the element under consideration.