Study type: Medical/biological study (experimental study)

Can electromagnetic fields emitted by mobile phones stimulate the vestibular organ? med./bio.

By: Pau HW, Sievert U, Eggert S, Wild W
Published in: Otolaryngol Head Neck Surg 2005; 132 (1): 43-49
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Aim of study (acc. to author)

1) To attempt to detect nystagmus during exposure to electromagnetic fields from a standardized irradiation source similar to a mobile phone.
2) To attempt to determine the dimension of thermal effects on the outer surface of the mobile phone and on tissues exposed to its electromagnetic irradiation.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 889.6 MHz
Modulation type: pulsed
  • power: 2.2 W peak value (at the feeding point)
  • power: 0.275 W mean (at the feeding point)
  • SAR: 1.9 mW/g average over mass (1 g) (below the skin)
  • SAR: 1.93 mW/g average over mass (1 g) (18 mm deep)
Exposure 2: 889.6 MHz
Modulation type: CW
  • power: 0.275 W mean (at the feeding point)
  • SAR: 1.9 mW/g average over mass (1 g) (below the skin)
  • SAR: 1.93 mW/g average over mass (1 g) (18 mm deep)
Exposure 3: 889.6 MHz
Modulation type: pulsed
Exposure duration: continuous for 15 min
  • power: 2.2 W peak value (at the feeding point)
  • power: 0.275 W mean (at the feeding point)
Exposure 4: 889.6 MHz
Modulation type: CW
Exposure duration: continuous for 15 min
  • power: 2.2 W peak value (at the feeding point)

Exposure 1

Main characteristics
Frequency 889.6 MHz
Type
Modulation
Modulation type pulsed
Pulse width 576 µs
Repetition frequency 217 Hz
Additional info

frame length of 4.61 ms
Exposure setup
Exposure source
Chamber The test person was in a lying position, the upper part of the body being raised to 30 degrees.
Setup Mobile phones connected to an external RF power supply were fixed to both sides of an adjustable chair and could be switched on alternatively.
Additional info Tests were carried out each ear at a time with or without continuous or pulsed EMF, resulting in 4 measurements for each inner ear (8 tests for each individual).
Parameters
Measurand Value Type Method Mass Remarks
power 2.2 W peak value measured - at the feeding point
power 0.275 W mean measured - at the feeding point
SAR 1.9 mW/g average over mass measured 1 g below the skin
SAR 1.93 mW/g average over mass measured 1 g 18 mm deep
Measurement and calculation details

RF power supplied by the generator to the connection sockets of the phones was routinely controlled before and after the test by a power meter with measuring head and upstream 30-dB attenuator. SAR was measured by T-Systems using the DASY-2 system.

Exposure 2

Main characteristics
Frequency 889.6 MHz
Type
Modulation
Modulation type CW
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power 0.275 W mean measured - at the feeding point
SAR 1.9 mW/g average over mass measured 1 g below the skin
SAR 1.93 mW/g average over mass measured 1 g 18 mm deep
Additional parameter details

The above values are assumed since not clearly stated in the article.

Exposure 3

Main characteristics
Frequency 889.6 MHz
Type
Exposure duration continuous for 15 min
Modulation
Modulation type pulsed
Pulse width 576 µs
Repetition frequency 217 Hz
Additional info

frame length of 4.61 ms
Exposure setup
Exposure source
Distance between exposed object and exposure source 25 mm
Chamber A mobile phone (power generation and control as in E1) was placed horizontally underneath an acrylic plate (2 mm thick) without any contact. The distance between loudspeaker and plate was 5 mm and between antenna and plate 23 mm.
Setup Thin, flat slices of tissue (special absorber foil, slices of sausage, sections of human temporal bone) were placed on the acrylic plate, and thermography was performed with an infrared camera mounted perpendicularly above the mobile phone. In a first step, temperature changes in the mobile phone itself were quantified after the acrylic plate was removed.
Additional info Examinations were performed with continuous as well as pulsed EMF.
Parameters
Measurand Value Type Method Mass Remarks
power 2.2 W peak value measured - at the feeding point
power 0.275 W mean measured - at the feeding point

Exposure 4

Main characteristics
Frequency 889.6 MHz
Type
Exposure duration continuous for 15 min
Modulation
Modulation type CW
Exposure setup
Exposure source
  • same setup as in E3
Distance between exposed object and exposure source 25 mm
Parameters
Measurand Value Type Method Mass Remarks
power 2.2 W peak value measured - at the feeding point
Additional parameter details

The power actually applied with CW is not clear. However, since the "more powerful continuous field" is mentioned several times (and 2 W at the end of the discussion), it must be assumed that the same peak power was used in this case as with the pulsed GSM signal.

Reference articles

  • Sievert U et al. (2004): [Biological effect of pulsed and continuous maximum-frequency (microwave) radiation on the inner ear]

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)

In no subject electromagnetic irradiation-induced nystagmus could be recorded. This corresponds to the findings that in the temporal bone very weak caloric effects could only be found in the tissue layers next to the irradiation source, whereas deeper regions seemed unaffected.
These data do not support the theory that mobile phone-induced electromagnetic irradiation may cause caloric negative effects in the human ear.

Study character:

Study funded by

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