The purpose of this study was to investigate whether combined exposure to extremely low frequency fields (50, 16.66, 13, 10, 8.33 and 4Hz) could cause changes in the human EEG activity.
The experiments were conducted on 33 healthy subjects (24 men and 9 women) in the age range of 20-59 years. Each subject participated in two sessions: one session included the sham exposure and the other session consisted of the exposure set-up with exposure periods for 2 minutes at each frequency, beginning with the highest frequency in a decreasing order and in between one minute EEG recording without exposure. One half of the subjects received exposure followed by sham exposure (exposure 1, sham exposure 2) , the other half was sham exposed first, followed by exposure (sham exposure 1, exposure 2).
| Exposure | Parameters |
|---|---|
| Exposure 1: 4–50 Hz |
|
| Exposure source | |
|---|---|
| Chamber | test person lies between the coils in a darkened and sound proof RF anechoic chamber |
| Setup | pair of circular Helmoltz coils with a radius of 65 cm and 250 turns of 0.8 mm copper wire each; exposure over the head of the test person; field perpendicular to the earth's north-south magnetic field |
| Sham exposure | A sham exposure was conducted. |
| Measurand | Value | Type | Method | Mass | Remarks |
|---|---|---|---|---|---|
| magnetic flux density | 20 µT | effective value | measured | - | +/- 0.57 µT |
The exposure 1 (group which was exposed first, followed by sham exposure) indicated a significant increase in beta waves at the frontal brain region, and a significant decrease in the alpha waves in parietal and occipital brain regions in the exposure 2 (exposure was conducted after sham exposure) . Significant decrease in the alpha waves at the occipital brain regions were observed in sham exposure 2 (sham exposure which followed electromagnetic irradiation).
This website uses cookies to provide you the best browsing experience. By continuing to use this website you accept our use of cookies.
