title: [Forensic aspects of thermal changes in human head hair].
abstract: Under experimental conditions, head hairs of individuals of different age were exposed to defined increases of temperature up to 450 degrees C and examined by transmitted- and reflected-light microscopy with and without polarization. Preliminary tests had shown that the hair changes alone do not allow conclusions as to the temperature acting on the hair. Especially in the range of 200 to 300 degrees C, the temperature gradient during the heating process and the exposure time were additional influencing factors. Thick hair and hair with a high water content showed more pronounced thermal changes than thin hair. Elasticity and permeability of the cuticle and the cementing substance (cell membrane complex CMC) are also relevant factors. When heating head hairs lacking a medulla, a multiform pseudo-medulla formed under certain conditions. In the presence of thermally induced structural disturbances (e.g. by using hair straighteners), foreign substances can penetrate more easily into the hair shaft from outside. The possibility of such exogenous contamination has to be taken into consideration when performing chemical and toxicological analyses of hair.
authors.forename: Harald
authors.initials: H
authors.lastname: Kijewski
mesh_terms: D000368:Aged; D002056:Burns / Q000266:history* / Q000473:pathology*; D004954:Esthetics; D005197:Famous Persons; D005260:Female; D006197:Hair / Q000473:pathology*; D049671:History, 18th Century; D049672:History, 19th Century; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007223:Infant; D007558:Italy; D008297:Male; D008853:Microscopy; D008857:Microscopy, Interference; D008875:Middle Aged; D009146:Music / Q000266:history*; D013696:Temperature