The author investigated the levels of various trace elements in scalp hair, which were measured by Inductively Coupled Plasma (ICP) emission spectrometry and atomic absorption spectrometry, and studied the physiological implications of these measurements with regard to age and sex. The subjects consisted of 129 Japanese children and adolescences (75 males and 54 females) from 1 to 19 years of age.
The following results were obtained:
The levels of zinc, phosphorus, calcium and magnesium increased with age, and iron, aluminum and manganese decreased. High contents of zinc, calcium, magnesium and copper in females, and sodium, potassium, iron, aluminum and manganese in males were revealed for all four age groups. Thus, if the appropriate levels of hair elements are discussed, the factors of age and sex must also be considered.
Based on principal component analysis for the eleven elements, they can be divided into two main groups. The first group consists of calcium, magnesium, phosphorus, zinc, mercury and copper, which correlate positively with age; the other consists of iron, manganese, aluminum, potassium and sodium, which correlate negatively with age. The principal component scores of each individuals correlate strongly with their age. The patterns of hair elements is greatly influenced by age, and it changes together with growth.
