Adverse environmental conditions in Shymkent significantly increase the risk of accumulation of lead in the bodies of the children of the third generation of the population residing in the contaminated areas, cause deteriorations of antioxidant defense in the respiratory system, greatly decline barrier-protective properties of cellular systems of the local immunity, disturb the process of hematopoiesis. Performed statistical analysis of the data permitted to identify a correlation relationship between the accumulation of lead in the soil and the change in the functional activity of the cells of buccal cheek epithelium, catalase activity in expired breath condensate. Haematological signs of lead poisoning include not only the number of reticulocytes, but also the correction (RPI) for the alteration with allowances made for the maturation of reticulocytes in peripheral blood circulation as early criterion for toxic anemia.