Instrumental neutron activation analysis and statistical approach for determining baseline values of essential and toxic elements in hairs of high school students.

The possibility to have reference values in clinical chemistry is really important and hair is an ideal tissue for tracing human health conditions. This study performed on 131 hair samples of high school students gives a better knowledge of element levels (i.d., As, Cd, Cr, Cu, Fe, Hg, Mn, S, Sb, Se, Sn and Zn) in subjects not exposed to specific contamination. A nuclear analytical technique, Instrumental Neutron Activation Analysis, has been employed for determining such species. These data can be used as tentative reference values in human hairs. The ratios among metals give important considerations on the general aspect of human health: the reference value represents an evaluation of the essential metabolic functions whereas an imbalance could be a factor influencing the rising of some pathologies, even if it is not an index of particular metabolic deficiency. A comparison with Italian studies shows a good agreement whereas some little discrepancies are evident with International studies. Further, a statistical approach (cluster analysis, Canonical Discriminant Analysis) was applied for determining the reference values. Taking in account these reference values a relationship with the environmental and pollutant compartments was studied confirming the starting hypothesis.