Assessment of reference values for hair minerals of Korean preschool children

Hair samples of 655 children (3–6 yr of age) from metropolitan and small cities in Korea were analyzed to determine the content of 23 minor and trace elements with the aim of assessing reference values. Fifteen essential elements (Fe, Zn, Cu, Ca, Mg, Mn, P, Na, K, Cr, Se, Li, V, Co, Mo) and 8 harmful elements (Pb, Al, Hg, As, Cd, Ba, Bi, U) were taken into account. Measurements were performed by inductively coupled plasma-mass spectrometry. The overall mean values were as follows (μ/g): Al, 8.78; As, 0.11; Ba, 0.32; Bi, 0.04; Ca, 212.47; Cd, 0.08; Co, 0.01; Cr, 0.47; Cu, 15.51; Fe, 12.62; Hg, 0.49; K, 34.10; Li, 0.01; Mg, 12.29; Mn, 0.29; Mo, 0.07; Na; 27.14; P, 121.21; Pb, 1.68; Se, 0.75; U. 0.04; V. 0.08; Zn, 69.99. There was no significant difference in hair mineral content between children living in metropolitan and small cities. There were positive correlations between age and the level of Zn, Ca, Na, P, Mn, and Li, but negative correlations between age and the level of Cr, V, and U. The proposed reference values for hair Zn, Mg, Ca, As, and Cd of Korean children were lower than those of other countries, but the values for other elements of hair were not significantly different from those of other countries.