Significance of elemental analysis of hair as a means of detecting environmental pollution

The correlation of metal concentrations in hair with those in the critical organs was investigated by tracer studies using ⁵¹Cr, ²⁰³Hg, ⁷⁵Se, ¹⁰⁹Cd, and ⁶⁵Zn in mice. The accumulation of these elements in organs of the mouse (including hair) during acute contamination was confirmed. Chronic studies to observe stable zinc and cadmium concentrations in various organs of the mouse at different ages manifested clear differences between zinc and cadmium accumulation patterns. The tracer study data on metal concentrations in 11 organs and those obtained by chemical analysis were compared. In the case of zinc, the correlation between the two is high, irrespective of the age of the mice; for cadmium no correlation was present in young mice but a correlation was seen in mice at ages of 19 weeks or more. Thus, the age-dependent variation of metals in organs is another factor that has been considered. Values for concentrations of several metals in critical organs and hair were compiled from the literature and compared. These studies led to the following conclusions: Hair is a reasonable indicator of mercury and chromium contamination, as these elements are readily deposited into hair and stay a comparatively long time. The time-dependent shifts of zinc and selenium in hair reflected their kinetics in the whole body, though their concentrations in hair were not higher than those in other organs. Hair was found to be a poor indicator of cadmium contamination, as the concentration of cadmium in hair was not parallel to that in the critical organs of the same mouse.