Correlations between the content of toxic and essential metals in the organism and characteristics of EEG potentials in youths under conditions of an urban environment

In 18-to 19-year-old students, the content of a number of microelements, as well as of calcium, in biologically stable tissues (hair samples) was measured using X-ray fluorescent analysis. In the tested persons, we observed a certain deficit of main elements (calcium, copper, and zinc), while in some persons the levels of toxic lead and strontium were exceeded. Correlation analysis of the parameters of EEG potentials (current EEG and evoked and event-related potentials, EPs and ERPs, respectively) showed the existence of a few significant (or close to those) correlations of the spectral powers of some rhythms and derivatives of a few indices of the background EEG and more numerous cases of correlations of the parameters of EPs and ERPs (latencies and amplitudes) with the contents of the studied elements. The physiological importance of metals, according to the number of characteristics of EEG potentials that correlate with their contents, can be arranged in descending order as follows: As, Zn > Ca > Cd > Pb > Sr. None of the studied parameters of EEG phenomena correlated with the level of copper. The strength of correlations varied from weak to mild (0.29 < R < 0.50). The densest correlations were observed for the concentrations of toxic lead and cadmium. With respect to the characteristics of ERPs, some of the elements under study demonstrated synergism (e.g., lead and arsenic), while others were in an antagonistic relation (cadmium and calcium). Neirofiziologiya/Neurophysiology, Vol. 38, No. 2, pp. 167–174, March–April, 2006.