Study type: Medical/biological study (experimental study)

Effects of short-term W-CDMA mobile phone base station exposure on women with or without mobile phone related symptoms. med./bio.

Published in: Bioelectromagnetics 2009; 30 (2): 100-113

Aim of study (acc. to author)

To measure the effects of short-term exposure to a W-CDMA mobile phone base station, and to observe whether they differ between women with mobile phone related symptoms and women without symptoms.

Background/further details

5000 questionaires including the frequency of mobile phone use and the presence/absence of mobile phone related symptoms were sent out to randomly sampled Japanese women (between 20 and 60 years). From 2472 valid responses 11 subjects with mobile phone related symptoms and 43 control subjects were recruited for a provocation study. Four different exposure conditions (each 30 min) were tested: continuous, intermittent, sham exposure with noise and sham exposure without noise.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.14 GHz
Exposure duration: continuous for 30 min
Exposure 2: 2.14 GHz
Exposure duration: intermittent, 5 min on or off, for 30 min

General information

There were four exposure conditions used: continuous EMF, intermittent EMF, sham, and noise exposure. During the tests performed on two days, each of the four conditions was administered to each subject in a double-blind, randomized order that was counterbalanced across subjects. Two sessions per day, each lasting about 90 min, were separated by at least 2 h.

Exposure 1

Main characteristics
Frequency 2.14 GHz
Type
Exposure duration continuous for 30 min
Modulation
Modulation type cf. additional info
Additional info

W-CDMA down-link signal similar to the one used in previous studies [Zwamborn et al., 2003; Regel et al., 2006] but with 64 dedicated physical channels added

Exposure setup
Exposure source
Distance between exposed object and exposure source 3 m
Chamber The shielded room had an area of 5.3 x 3.0 m² and a height of 2.745 m, an ambient temperature of 23 °C, a humidity of 50%, and a sound level below 40 dBA. Flat wave absorbers (23.6 dB at 2.0 GHz) covered most of the floor, ceiling, and three walls in front of the horn antenna.
Setup The subject was seated on a polypropylene chair in front of a wooden desk with the psychological test equipment. The horn antenna, 1.15 m tall, was placed behind the subject and to the left at a height of 0.755 m being approximately that of an average Japanese female aged 20-59 sitting on a 0.4-m high chair.
Sham exposure A sham exposure was conducted.
Additional info The noise used was produced by and recorded near the RF power amplifier used in the experiment. The noise level at the subject's head position was 65 dBA.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 10 V/m effective value measured and calculated - at the head
power density 0.265 W/m² effective value measured and calculated - at the head
SAR 0.0015 W/kg average over mass calculated whole body -
SAR 0.0013 W/kg average over mass calculated brain -
SAR 0.0078 W/kg peak value calculated 10 g in the brain
SAR 0.019 W/kg peak value calculated 10 g in the body

Exposure 2

Main characteristics
Frequency 2.14 GHz
Type
Exposure duration intermittent, 5 min on or off, for 30 min
Modulation
Modulation type cf. additional info
Additional info

same as in E1

Exposure setup
Exposure source
Additional info In the intermittent exposure condition, EMF was turned on or off randomly every 5 min. The on/off periods were counterbalanced, such that EMF was on and off for 50% of the time in each subject.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 10 V/m effective value measured and calculated - at the head
power density 0.265 W/m² effective value measured and calculated - at the head
SAR 0.0015 W/kg average over mass calculated whole body -
SAR 0.0013 W/kg average over mass calculated brain -
SAR 0.0078 W/kg peak value calculated 10 g in the brain
SAR 0.019 W/kg peak value calculated 10 g in the body

Reference articles

  • Neubauer G et al. (2007): Feasibility of future epidemiological studies on possible health effects of mobile phone base stations.
  • Regel SJ et al. (2006): UMTS base station-like exposure, well-being, and cognitive performance.
  • Nagaoka T et al. (2004): Development of realistic high-resolution whole-body voxel models of Japanese adult males and females of average height and weight, and application of models to radio-frequency electromagnetic-field dosimetry.
  • Zwamborn APM et al. (2003): Effects of Global Communication system radio-frequency fields on Well Being and Cognitive Functions of human subjects with and without subjective complaints.

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 group with mobile phone related symptoms did not differ significantly from the controls in their ability to detect exposure to electromagnetic fields. Discomfort and negative mood was significantly greater in the group with mobile phone related symptoms than in the control groups, irrespective of whether the electromagnetic field was actually on or off. The two groups did not differ in their responses to real or sham exposure according to any psychological, cognitive or autonomic measure.
The authors did not find a link between hypersensitivity symptoms and exposure to electromagnetic fields from base stations.

Study character:

Study funded by

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