Incorporation of trace elements into hair structure

Examining blood and urine provides an immense insight into human diseases. It is natural to hope that the hair studies will be added routinely to the examinations. Human head hair is a recording filament which can reflect metabolic changes of many elements over a long period of time. The idea of hair analysis is very inviting, because hair is easily samples, shipped and analyzed. In this paper the authors propose a method for the determination of some diffusion parameters from experimental data on the distribution of trace element concentrations in hair and then a method for the determination of the radial diffusion constants of Se, Zn and Pb. The authors' model of hair structure with respect to diffusion is based on the supposition of cross-sectional homogeneity as well as the longitudinal homogeneity of hair. This supposition implies nonisotropic diffusion in hair which is described by two diffusion constants. Diffusion constants can be determined by experiment on wetting hair in solvents or by measurements of natural contamination of hair in air. The first type of experiments can be arranged in various ways to separate radial diffusion from the longitudinal one and, consequently, to determine two diffusion constants from various sets of experiments. The authors' aim is to consider only radial diffusion in hair and to determine the radial diffusion constants of Se, Zn and Pb