Study type: Medical/biological study (experimental study)

Long-Term Evolution electromagnetic fields exposure modulates the resting state EEG on alpha and beta bands. med./bio.

Published in: Clin EEG Neurosci 2017; 48 (3): 168-175

Aim of study (acc. to author)

The effects of exposure to 2.61 GHz electromagnetic field (LTE) on the human EEG should be investigated.

Background/further details

The results of a previous study on brain activity by the authors (Lv et al. 2014) should be confirmed using another method.
25 healthy male volunteers participated in 2 sessions, which were separated by 1 week. Each session lasted 50 minutes and comprised 5 time slots at 10 minutes. In the first (pre-exposure) and last slot (post-exposure), EEG was always measured without EMF exposure. The 3 intermediate slots were either used for EMF exposure in one random session or for sham exposure in the other.
All subjects were moderate mobile phone users (voice communication for less than 30 minutes per day) and none used a mobile phone for more than 10 minutes during the day prior to the experiments.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.61 GHz
Exposure duration: continuous for 30 minutes

Exposure 1

Main characteristics
Frequency 2.61 GHz
Type
Exposure duration continuous for 30 minutes
Additional info LTE
Modulation
Modulation type cf. additional info
Additional info

applied radio frame (10-ms total length) consisted of 2 half-frames of equal length; each half-frame comprised 5 subframes, each 1 ms in length; maximum emission configuration was used (6 uplink subframes in the radio frame); radiation duration (including the uplink subframes and uplink pilot time slot special subframes) accounted for 63.3% of the total length of the frame

Exposure setup
Exposure source
Distance between exposed object and exposure source 1 cm
Setup subjects were in sitting position with eyes closed; plastic spacer of 1 cm was used to maintain the distance between the right ear and a standard dipole
Sham exposure A sham exposure was conducted.
Additional info right ear was exposed because subjects were assumed to be right-hand dominant
Parameters
Measurand Value Type Method Mass Remarks
SAR 1.34 W/kg peak value calculated 10 g with electrodes
SAR 1.96 W/kg peak value calculated 1 g with electrodes
power 0.25 W peak value - - power delivered to the dipole antenna

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Exposure to the electromagnetic field significantly reduced the power and inter-hemispheric coherence of alpha waves and beta waves in the frontal and temporal brain regions during and after exposure in comparison to the sham exposure and compared to the pre-exposure condition. No significant change was observed in the power or the inter-hemispheric coherence of brain waves in different time slots during and after the exposure.
Results for delta waves and theta waves were not presented.
The authors conclude that exposure to a 2.61 GHz electromagnetic field (LTE) might modulate alpha waves and beta waves in the human EEG, supporting previous results.

Study character:

Study funded by

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