Correlations between EEG Characteristics and Contents of Some Micro- and Macroelements (Lead,Strontium, and Calcium) in the Organism of 12- to 13-Year-Old Children Living in Ecologically Unfavourable Regions of Ukraine

In 12- to 13-year-old children, inhabitants of regions of Ukraine with high levels of industrial contamination, we found higher contents of lead and calcium, as compared with the upper limits of the norm, in samples of biologically stable tissues (hairs). Concentrations of strontium were within the limits of reference values. Correlation analysis of the EEG frequency components vs levels of the above-mentioned metals demonstrated the existence of significant (or close to significant) relations between normalized spectral powers of the rhythms of background EEG recorded at different functional states (eyes open/closed, solving an arithmetic task) and concentrations of these elements. According to the number of the correlations found and their strength, the order of significance of the effects of the above elements with respect to the pattern of EEG activity was the following: Ca > Sr > Pb. The intensity of significant correlations varied from mild to moderately strong (0.41 < r < 0.70). The tightest correlations with the levels of all elements were observed under conditions of cognitive loading (solving an arithmetic task). High-frequency EEG components (β1 and β2 rhythms) were found to be the EEG components most sensitive to the contents of the mentioned elements.