Study type: Medical/biological study (experimental study)

Pulse modulated radiofrequency exposure influences cognitive performance. med./bio.

Published in: Int J Radiat Biol 2016: 1-8

Aim of study (acc. to author)

The effects of exposure to a 920 MHz electromagnetic field on human cognitive performance should be investigated.

Background/further details

36 participants (half male, aged 18-52) participated in 4 test sessions separated by a period of at least 7 days: 1) preliminary calibration session, 2) sham exposure, 3) exposure to 1 W/kg, 4) exposure to 2 W/kg.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 920 MHz
Modulation type: pulsed
Exposure duration: continuous for 30 minutes
  • SAR: 1 W/kg spatial average (10 g) (peak value)
Exposure 2: 920 MHz
Modulation type: pulsed
Exposure duration: continuous for 30 minutes
  • SAR: 2 W/kg spatial average (10 g) (peak value)

Exposure 1

Main characteristics
Frequency 920 MHz
Type
Exposure duration continuous for 30 minutes
Modulation
Modulation type cf. additional info, pulsed
Additional info

GSM-like signal (as emitted by a mobile phone handset in active mode while transmitting voice) including the basic GSM frequency components 8.33, 216.6, 1733 Hz and corresponding harmonics; crest factor = 8.3

Exposure setup
Exposure source
Chamber participants were seated inside a Faraday cage
Setup sXh920 planar exposure system was used; 2 RF antennas placed on wooden pillars were positioned 42 mm vertically above the ear canal at a distance of 115 mm from the head; only the left hemisphere was exposed to RF and participants were not made aware of which antenna was emitting; brown noise was used to mask any sounds made by the exposure system; subjects were covered with a water perfusion garment to clamp body skin temperature to 34°C
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 1 W/kg spatial average calibration 10 g peak value

Exposure 2

Main characteristics
Frequency 920 MHz
Type
Exposure duration continuous for 30 minutes
Modulation
Modulation type cf. additional info, pulsed
Additional info

GSM-like signal (as emitted by a mobile phone handset in active mode while transmitting voice) including the basic GSM frequency components 8.33, 216.6, 1733 Hz and corresponding harmonics; crest factor = 8.3

Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 2 W/kg spatial average calibration 10 g peak value

Reference articles

  • Loughran SP et al. (2013): No increased sensitivity in brain activity of adolescents exposed to mobile phone-like emissions.
  • Murbach M et al. (2012): Exposure system to study hypotheses of ELF and RF electromagnetic field interactions of mobile phones with the central nervous system.
  • Huber R et al. (2005): Exposure to pulse-modulated radio frequency electromagnetic fields affects regional cerebral blood flow.
  • Huber R et al. (2002): Electromagnetic fields, such as those from mobile phones, alter regional cerebral blood flow and sleep and waking EEG.

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)

The reaction time in the working memory task was significantly decreased after exposure to the 1 W/kg and 2 W/kg electromagnetic fields compared to the sham exposure. Other parameters did not show significant differences.
The authors conclude that exposure of adult subjects to a 920 MHz electromagnetic field might accelerate the cognitive performance.

Study character:

Study funded by

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