Study type: Medical/biological study (experimental study)

[Biological effect of pulsed and continuous maximum-frequency (microwave) radiation on the inner ear] med./bio.

Biologische Wirkung gepulster und kontinuierlicher Höchstfrequenz-(Mikrowellen-)Strahlung auf das Innenohr

By: Sievert U, Pau HW, Eggert S, Goltz S
Federal Institute for Occupational Safety and Health and Occupational Medicine (BAuA)
2004, Schriftenreihe der Bundesanstalt für Arbeitsschutz und Arbeitsmedizin, FB1019: 1-64
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Aim of study (acc. to author)

To study the biological effects of high frequency irradiation produced by the GSM mobile phone on the inner ear with its sensors of the vestibular and auditory systems.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 889.6 MHz
Modulation type: CW
Exposure duration: continuous for about 1, 2, or 3 min per ear depending on the examination
  • power: 255 mW mean
  • SAR: 1.25 W/kg average over mass (1 g)
  • SAR: 0.77 W/kg average over mass (10 g)
Exposure 2: 889.6 MHz
Modulation type: pulsed
Exposure duration: continuous for about 1, 2, or 3 min per ear depending on the examination
  • power: 2.2 W peak value
  • power: 255 mW mean
  • SAR: 1.25 W/kg average over mass (1 g)
  • SAR: 0.77 W/kg average over mass (10 g)
Exposure 3: 889.6 MHz
Modulation type: CW
Exposure duration: continuous for 14, 16, 18, 22, or 23 min depending on the material
  • power: 255 mW mean
  • SAR: 1.25 W/kg average over mass (1 g)
  • SAR: 0.77 W/kg average over mass (10 g)
Exposure 4: 889.6 MHz
Modulation type: pulsed
Exposure duration: continuous for 15, 16, 18, or 31 min depending on the material
  • power: 2.2 W peak value
  • power: 255 mW mean
  • SAR: 1.25 W/kg average over mass (1 g)
  • SAR: 0.77 W/kg average over mass (10 g)

Exposure 1

Main characteristics
Frequency 889.6 MHz
Type
Exposure duration continuous for about 1, 2, or 3 min per ear depending on the examination
Modulation
Modulation type CW
Exposure setup
Exposure source
Setup The exposure setup for test persons consisted of two mobile phones that were prepared for external feeding from a signal generator and a broadband power amplifier via a coaxial cable with additional shield surface wave suppression. The mobile phones were attached to adjustable non-conductive holders mounted on a chair for test persons. The phone on the examined side was activated by a coaxial relay.
Additional info SAR and penetration were measured according to ES 59006 (CENELEC 1998) with the aid of flat and real size head phantoms and the phone in the "intended use position". The highest SAR value was detected at the root point of the antenna.
Parameters
Measurand Value Type Method Mass Remarks
power 255 mW mean measured - -
SAR 1.25 W/kg average over mass measured 1 g -
SAR 0.77 W/kg average over mass measured 10 g -
Measurement and calculation details

Adjustment and control of the power fed to the mobile phones was supported by a power meter with a probe and an inserted 30 dB attenuator.

Exposure 2

Main characteristics
Frequency 889.6 MHz
Type
Exposure duration continuous for about 1, 2, or 3 min per ear depending on the examination
Modulation
Modulation type pulsed
Pulse width 576 µs
Duty cycle 12.5 %
Repetition frequency 217 Hz
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power 2.2 W peak value measured - -
power 255 mW mean measured - -
SAR 1.25 W/kg average over mass measured 1 g -
SAR 0.77 W/kg average over mass measured 10 g -

Exposure 3

Main characteristics
Frequency 889.6 MHz
Type
Exposure duration continuous for 14, 16, 18, 22, or 23 min depending on the material
Modulation
Modulation type CW
Exposure setup
Exposure source
Setup For the exposure of samples during thermography a mobile phone was positioned horizontally at a distance of 3 cm parallel to the edge of the wooden worktop of a trolley. Samples were placed in a dish of Piacryl (with walls of 2 mm), the bottom of which was 5 mm apart from the casing and (according to the shape) farther from the antenna of the mobile phone.
Additional info Measurements were made with the mobile phone alone, with an absorbing foil, with animal tissue (sausage slice), and with pars petrosa of the human temporal bone (dry and wet).
Parameters
Measurand Value Type Method Mass Remarks
power 255 mW mean measured - -
SAR 1.25 W/kg average over mass measured 1 g -
SAR 0.77 W/kg average over mass measured 10 g -

Exposure 4

Main characteristics
Frequency 889.6 MHz
Type
Exposure duration continuous for 15, 16, 18, or 31 min depending on the material
Modulation
Modulation type pulsed
Pulse width 576 µs
Duty cycle 12.5 %
Repetition frequency 217 Hz
Exposure setup
Exposure source
  • same setup as in E3
Parameters
Measurand Value Type Method Mass Remarks
power 2.2 W peak value measured - -
power 255 mW mean measured - -
SAR 1.25 W/kg average over mass measured 1 g -
SAR 0.77 W/kg average over mass measured 10 g -

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 thermographic investigations made on various model materials and on the human temporal bone indicate that the mobile phone does not induce any increases of temperature which would lead to a relevant stimulus for the auditory and vestibular system.
Video-nystagmographic recordings under electromagnetic field exposure did not result in vestibular reactions generated by electromagnetic field exposure, neither for the pulsed nor for the continuous high frequency field.
Compared with the recording without electromagnetic field, the brainstem electric response audiometry tests under electromagnetic field exposure of 24 ears (12 subjects) did not reveal any changes of the parameters investigated, i.e. absolute latency of the peaks I, III, V and the interpeak latency between the peaks I and V.
The distortion product otoacoustic emissions (DPOAE) recorded on 20 ears (10 subjects) do not indicate, comparing the three measuring situations, i.e. "before electromagnetic field exposure", "pulsed electromagnetic field exposure" and "continuous electromagnetic field exposure", any possible impacts of the high-frequency electromagnetic field on the spectrum or levels of otoacoustic emissions for none of the subjects.
The data show that the electromagnetic fields generated in using the mobile phone do not have an effect on the inner ear and auditory system to the colliculus inferior in the brainstem and on the vestibular receptors in the inner ear and the vestibular system.

Study character:

Study funded by

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