The interpretation of human hair trace element concentrations

Scalp hair samples collected from 86 Canadian elderly, non-institutionalized women (mean age 66.6 +/- 6.2 y) on two separate occasions ten weeks apart, were analyzed for Zn, Cu and Mn content. Fasting blood samples were also collected and serum Zn, Cu and albumin content determined. Median hair Zn, Cu and Mn and mean serum Zn and albumin concentrations were not significantly different at the pre- and post-study periods. Furthermore, hair Zn concentrations at the two sampling times were positively and significantly correlated as were hair Cu, hair Mn, serum Zn and serum albumin values. In contrast no significant correlation related the hair and serum Zn values and hair and serum Cu values at any time. The constancy of the hair Zn, Cu and Mn concentrations at the two sampling periods may reflect the homeostatic regulation which controls absorption and hence body trace element content. In addition, results indicate that, after careful laboratory washing, the effects of adventitious contamination on hair trace element content are small, and can be effectively ignored.