Study type: Medical/biological study (experimental study)

Individual changes in human EEG caused by 450 MHz microwave modulated at 40 and 70 Hz med./bio.

Published in: Environmentalist 2007; 27 (4): 511-517

Aim of study (acc. to author)

To study the effect of microwaves modulated at different frequencies (40 and 70 Hz) on human electroencephalographic (EEG) rhythms.

Background/further details

15 subject participated (eight males, 7 females). All subjects passed two EEG recordings on two different days under microwave exposure and sham exposure.



Exposure Parameters
Exposure 1: 450 MHz
Exposure duration: 40 min. = 10 cycles of each modulation frequency (1 min. on - 1 min. off)

Exposure 1

Main characteristics
Frequency 450 MHz
Exposure duration 40 min. = 10 cycles of each modulation frequency (1 min. on - 1 min. off)
Modulation type cf. additional info
Additional info

pulse-modulated modulation frequencies: 40 Hz and 70 Hz duty cycle = 50%

Exposure setup
Exposure source
Distance between exposed object and exposure source 10 cm
Setup antenna placed near the left side of the test person's head
Sham exposure A sham exposure was conducted.
Measurand Value Type Method Mass Remarks
power 1 W - - - -
power density 0.16 mW/cm² - estimated - at the scalp
SAR 0.35 W/kg - - - -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

450 MHz microwave exposure modulated at 40 Hz caused statistically significant changes in the EEG time variability (i.e. LDLVP) in four subjects (26.7%) and energy variations (increase in energy of beta wave (beta 2) frequency band) in two subjects (13.3%). The LDLVP analysis and relative changes in EEG energy did not detect significant effects of microwave exposure for the whole group.
Statistical evaluation performed for the whole group revealed significant difference between exposed and sham exposed EEG only for the beta ratio (as parameter for energy distribution).
In conclusion, the main trend of changes in the present study was the increase in the EEG beta wave energy and the effect was more evident at the modulation frequency closer to the physiological EEG rhythms (40 Hz).

Study character:

Study funded by

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