STUDY OF THE AGE AND SEX DEPENDENCE OF TRACE-ELEMENTS IN HAIR BY CORRESPONDENCE-ANALYSIS

The aim of the study was to examine the potential of multidimensional analysis, and in particular of correspondence analysis (CA), in bringi ng to Light the influence of sex and age on trace element (TE) concent rations in hair from an unselected French population. Sixteen elements (S, Hg, Se, Zn, Pb, Cd, Ni, Co, Mn, Fe, Cr, Mg, Al, Ca, Cu, Ag) were assayed by inductively coupled argon plasma (ICAP) emission spectrosco py in the scalp hair of 135 men and 346 women. In spite of the high ba ckground noise, CA was able to reveal the differing patterns in males and females. For instance, in this population, higher relative levels of the essential elements, Ca, Mg, Zn, and Cu, but also of Ag, charact erized women's hair, whereas higher relative levels of the heavy metal s, Fe and Pb, were associated with men's hair. Al and Ag were unexplai nedly high in the hair of the youngest members of the population. The Cu and Co of youth seemed to give way to a predominance of Zn in matur ity. The hair of individuals in their forties tended to be richest in Ca and Mg, but these elements decreased with advancing age. Heavy meta ls (Hg, Pb, Fe) accumulated with age, whereas Se, Mn, and Cr seemed in dependent of age. CA is manifestly a very useful tool for revealing un derlying dimensions in complex dynamic systems and unsuspected relatio nships among variables. Clearly the significance of the high AI and Ag contents in the hair of certain members of the population, especially of the very young, needs to be investigated from both physiological a nd toxicological aspects.