The 450 MHz microwave exposure modulated at 40 and 70 Hz (15 subjects) and 217 and 1,000 Hz (19 subjects) frequencies was applied. The data of previous studies at 7, 14 and 21 Hz modulation were included into the analysis (Hinrikus et al. 2008a and Hinrikus et al. 2008b).
The data showed that microwave exposure increased the EEG energy at EEG frequencies lower or close to the modulation frequency (different modulation frequencies affected different EEG frequency bands). No effect was detected at EEG frequencies higher than the modulation frequency. Statistically significant alterations were caused by exposure in the EEG alpha wave and beta wave frequency bands; no significant effect was found in the theta wave frequency band.
The results suggest that telecommunication devices with complex spectrum of modulation frequencies like mobile phones can affect human EEG frequency bands.