Factors affecting the trace-metal content of human hair

Abstract

Both present-day and historical head-hair samples up to 300 years old are being analysed by neutron activation for more than 30 trace elements. This study, designed to determine an historical base-line for the human intake of trace metals and to provide an evaluation of the present-day rate of increase and sources of environmental pollution, has direct forensic applicability. Modern samples being analysed in this study include hair from U. S. Naval Academy midshipmen and U.S. Air Force Academy cadets obtained upon arrival at the Academies in mid-1971 and again at later intervals during which trace-metal equilibration due to fixed diets and environmental conditions is presumed to occur. A wide variety of factors such as age, sex, hair structure and color, geographic location, general diet, socieconomic status are being considered in evaluating the analysis data. Examples of some of the initial data obtained from the analysis of the first three sets of Naval Academy midshipmen hair are presented.