The Distribution of Trace Elements in Human Hair and its Possible Effect on Reported Elemental Concentration Levels

For some twenty years forensic scientists have attempted, with only limited success, to develop a reliable trace element ‘fingerprint' method for the identification of human head hairs. It is the author's belief that many of the operational failures have resulted because of a lack of fundamental information concerning the precise distribution, at any particular point in time, of the various entrained trace elements in the complex hair matrix. A knowledge of trace element distributions within the hair shaft has been shown to be of vital importance when reporting certain elemental levels in hair. Some of the analytical discrepancies which can arise as a direct result of such elemental distributions and consequently the Problems of interpretation involved when attempts are made to compare, for example, hairs found at the scene of a crime with those from a suspect, are discussed.