Effects of natural environments on drug contents in nails: comparison of drug residual rates between nails and hair to determine the drug-use history of corpses in unnatural death cases using micro-segmental analysis.

In comparison with hair data obtained under the same environmental conditions, light affected drugs in the hair rather than in nails, whereas water and soil greatly affected drugs in the nails rather than in hair. Although the disposition of drugs incorporated in the tissues differed between nails and hair, the analytes were detected in nails and hair strands left in severe natural environments. MSA could be useful for estimating drug-use histories and personal profiles using the nails and hair of a corpse.