The Effect of Age and Gender on 37 Chemical Element Contents in Scalp Hair of Healthy Humans

Biol Trace Elem Res. 2009 Jul 21.

The Effect of Age and Gender on 37 Chemical Element Contents in Scalp Hair of Healthy Humans.

Zaichick S, Zaichick V.

Northwestern University, Chicago, IL, 60611, USA.

The effect of age and gender on minor and trace element contents in the scalp hair of 80 relatively healthy 15- to 55-year-old women and men was investigated. Contents or upper limit of contents of 37 chemical elements in the scalp hair were determined by instrumental neutron activation analysis. Mean values (M +/- SEpsilonMu) for the mass fraction of Ag, Au, Ba, Br, Ca, Ce, Cl, Co, Cr, Eu, Fe, Hf, Hg, I, K, La, Lu, Mg, Mn, Na, Rb, Sb, Sc, Se, Sm, Sr, Th, and Zn (milligrams per kilogram of dry hair) were 0.191 +/- 0.018, 0.0102 +/- 0.0014, 6.33 +/- 0.68, 3.59 +/- 0.26, 1320 +/- 110, 0.369 +/- 0.055, 1245 +/- 133, 0.0707 +/- 0.0054, 2.78 +/- 0.22, 0.0082 +/- 0.0021, 88.2 +/- 6.7, 0.040 +/- 0.012, 0.145 +/- 0.009, 6.93 +/- 1.05, 146 +/- 14, 0.238 +/- 0.025, 0.0030 +/- 0.0007, 163 +/- 17, 2.29 +/- 0.30, 344 +/- 31, 0.65 +/- 0.10, 0.062 +/- 0.005, 0.0100 +/- 0.0012, 0.248 +/- 0.008, 0.0090 +/- 0.0010, 45.7 +/- 3.5, 0.0168 +/- 0.0019, and 154 +/- 3, respectively. The upper limits of contents of Cd, Cs, Gd, Nd, Ta, Tb, Tm, and Yb were </=0.17, </=0.013, </=0.104, </=0.19, </=0.011, </=0.0048, </=0.0057, and </=0.0047, respectively. In all hair samples, the contents of As was under detection limits <0.01. The tendency for the Ce, La, and Th content to increase with age was found in the human hair, but statistically significant changes were shown for females only. The mass fraction of Rb in the male scalp hair increases and of Cl decreases with age. It was shown that higher Au, Ca, Mg, and Sr mass fractions as well as lower Cl, Fe, I, Sc, Se, and Sm content were typical of female hair as compared to those in male hair.

So rubidium increases with age and chlorine decreases with age in male scalp hair? What exactly does this mean?