Assessment of reference values for elements in hair of urban normal subjects

Hair is quite attractive as a biological indicator because of the simplicity of sampling and storage. The analysis of trace and minor elements in this tissue has been used in a diversity of applications, including nutritional, environmental, medical, and occupational studies. Within this context the availability of reliable reference values plays a key role. Scalp hair samples taken from 225 urban subjects not older than 15 years were analyzed for 18 elements. The method chosen for the quantification of elements in hair has been ICP-AES in all cases because of its multielemental capability, wide dynamic range, adequate detection limits, and relative freedom from matrix interferences. The following mean values were obtained (in μg g−1): Al, 11.6; As, 0.10; Ca, 416; Cd, 0.20; Co, 0.86; Cr, 0.67; Cu, 22.4; Fe, 17.9; Mg, 25.9; Mn, 0.41; Mo, 0.44; Ni, 0.97; P, 185; Pb, 8.10; Se, 0.84; Ti, 1.05; V, 1.44; and Zn 144. These data were analyzed statistically to ascertain possible significant differences according to sex and age.