Study type: Medical/biological study (experimental study)

[Effects of Electromagnetic Fields Emitted by Cellular Phone on Auditory and Vestibular Labyrinth] med./bio.

Wirkung elektromagnetischer Felder des GSM-Mobilfunksystems auf auditives und vestibuläres Labyrinth und Hirnstamm

By: Sievert U, Eggert S, Goltz S, Pau HW
Published in: Laryngorhinootologie 2007; 86 (4): 264-270
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Aim of study (acc. to author)

To perform thermographic measurements and to study the biological effects of the radiofrequency irradiation produced by a GSM mobile phone on the inner ear with its sensors of the vestibular and auditory system.

Background/further details

Thermographic investigations were made on various model materials and on the human temporal bone.
Video-nystagmographic recordings of 13 subjects, brainstem electric response audiometry of 24 ears, and recordings of distortion product otoacoustic emissions of 20 ears were performed.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 889.6 MHz
Modulation type: pulsed, CW
Exposure duration: repeated exposure for about 2 or 9 min per ear, depending on the examination, with a 3-min interval between registrations
  • power: 2.2 W peak value
  • power: 255 mW mean
  • SAR: 1.9 mW/g average over mass (1 g) (under the skin)
  • SAR: 1.93 mW/g average over mass (1 g) (at 18 mm depth)
Exposure 2: 889.6 MHz
Modulation type: pulsed, CW
Exposure duration: continuous for about 15 min
  • power: 2.2 W peak value
  • power: 255 mW mean
  • SAR: 1.9 mW/g average over mass (1 g) (under the skin)
  • SAR: 1.93 mW/g average over mass (1 g) (at 18 mm depth)

General information

All tests were performed without and with CW and pulsed RF signals in various orders depending on the examination.

Exposure 1

Main characteristics
Frequency 889.6 MHz
Type
Exposure duration repeated exposure for about 2 or 9 min per ear, depending on the examination, with a 3-min interval between registrations
Modulation
Modulation type pulsed, CW
Exposure setup
Exposure source
Setup The exposure setup for test subjects 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 plastic holders mounted on a chair for test subjects. The phone on the examined side was activated by a coaxial relay.
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 2.2 W peak value measured - -
power 255 mW mean measured - -
SAR 1.9 mW/g average over mass measured 1 g under the skin
SAR 1.93 mW/g average over mass measured 1 g at 18 mm depth
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. SAR and penetration were measured on phantoms using a Dosimetric Assessment System (DASY-2).

Exposure 2

Main characteristics
Frequency 889.6 MHz
Type
Exposure duration continuous for about 15 min
Modulation
Modulation type pulsed, 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 a 2-mm absorbing foil, with 2-mm animal tissue (sausage slice), and with pars petrosa of the human temporal bone (dry and wet) cut at about 18 mm depth and positioned with the outer auditory canal above the loudspeaker.
Parameters
Measurand Value Type Method Mass Remarks
power 2.2 W peak value measured - -
power 255 mW mean measured - -
SAR 1.9 mW/g average over mass measured 1 g under the skin
SAR 1.93 mW/g average over mass measured 1 g at 18 mm depth

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 measurements suggest that the mobile phone does not induce any increases of temperature which would lead to a relevant stimulus for the auditory and vestibular system.
The video-nystagmographic recordings do not furnish any indication of vestibular reactions generated by the electromagnetic field. Compared with the recording without the electromagnetic field, the brainstem electric response audiometry under exposure did not reveal any changes. The distortion product otoacoustic emissions do not indicate any possible impacts of the radiofrequency field.
The data show that the electromagnetic fields generated by a 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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