Literature data related to the merit of hair as a chronological diary of drug exposure, as examined by segmental analysis, are reviewed with emphases on the mechanisms of drug incorporation, physiology of hair growth, and findings resulting from research effort and routine analytical results. In a single anagen strand, a drug dose may be incorporated, within the hair follicle, to a drug-containing zone of approximately 2-5 mm width, which appears at the skin surface 1-5 days after drug exposure and moves regularly away following the strand's growth rate. This process is disturbed by deposition from sweat, sebum, and in rare cases environmental contamination, as well as by elimination during hair care or chemical treatment. In a hair tuft, the time resolution is seriously deteriorated by the presence of 5-15

作者：F, Pragst；M, Rothe；K, Spiegel；F, Sporkert

来源：Forensic science review 1998 年 10卷 2期