[Results of biomonitoring for zinc in children of the Irkutsk region].

The aim of the work is to test the application of the method of evaluating the content of zinc in the hair of the child population for solving SHM tasks on the example of the Irkutsk region. In total 426 children aged 5-6 years were examined, selected in four groups. The first group was consisted of children residing in a large industrial center to the south of the region, the second--in the the small town of the central part, the third group was formed by rural children of the central region, and the fourth--the northern and foothill regions. Hair analysis was performed by atomic absorption method. Found that zinc content in hair was established to be prone to significant variability. In children of the southern industrial center of the region (Group 1) there was noted the least amount of zinc (median is of 65.6 mg/kg). In 53% of the samples the element content was below the absolute norm (AN), out of which 25% below the biologically permissible limits (BPL). Only in 8.5% of the samples the zinc content exceeded AN and 3%-- BPL. In the range of AN there are 38% of the children, within the BPL range--71%. In the 2nd, the median of the concentration of zinc in the hair was 152.5 mg/kg. In the range of the AN there were 53% of the samples, in the BPL range--86% of the samples. Deviations from the reference levels were observed in the direction of exceedence of values. 36% of rural children (group 3) are provided with zinc within the limits of AN, 93%--within BPL. Only in 6% of children the zinc content in the hair below AN or BPL. In the 4th Group only 7.7% of samples were in the AN range and 27% of the samples--in the BPL range. 92% of the samples were way beyond the limits of AN and 73%--beyond the BPL. In most of the samples the higher content of zinc was observed. The highest concentrations of zinc in hair were observed in children living in the northern foothills and the Irkutsk region, which are characterized by elevated levels of this metal in the soil. In the diet of the inhabitants of these regions there is prevailed local food of animal origin, which is the main source of the entry of zinc into the body. In areas of intensive industrial development, despite the rather high zinc content in the objects of the environment, there was noted the high frequency of the zinc deficiency states, especially in conditions of complex chemical factors exposure and lifestyle that may be associated with features of not only input, but also the absorption of zinc in the body children.