Heavy metals are most common pollutants in large industrial cities. Differences were first shown in the distribution of concentrations of toxic and biogenic heavy metals in the hair of children. Zinc and copper had dispersion close to normal values, whereas lead, cadmium, and nickel had asymmetric dispersion. Scales were first developed for rating the levels of heavy metals in the children's hair in cities. A typology of microareas was also first developed by the level of metal pollution. The permanent stay of children in the highly polluted areas causes a high accumulation of lead in the hair and it is a risk factor of morphofunctional abnormalities and chronic diseases.