Study type: Medical/biological study (experimental study)

Cognitive function and symptoms in adults and adolescents in relation to rf radiation from UMTS base stations. med./bio.

Published in: Bioelectromagnetics 2008; 29 (4): 257-267

Aim of study (acc. to author)

This study was designed to investigate the acute effects of radio frequency electromagnetic fields emitted by UMTS mobile phone base stations on human cognitive function and symptoms in vivo.

Background/further details

Adolescents (mean age: 15.7 years; 17 males, 23 females) and adults (mean age: 31.1 years; 24 males, 16 females), neurologically healthy were selected for this study. During exposure the participants performed different cognitive tasks (amongst others "Trail Making B" test) and completed a questionnaire measuring self reported subjective symptoms. In the applied "Trail Making B" test the participants had to draw lines alternating beween numbers and letters in consecutive order. The time at which the task was completed correctly was measured.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2,140 MHz
Modulation type: CW
Exposure duration: continuous for 45 min
Exposure 2: 2,140 MHz
Exposure duration: continuous for 45 min

General information

All participants attended four exposure sessions on separate days at the same time of day. They were exposed to four conditions: sham, CW, a signal modulated as UMTS, and UMTS including all control features in a randomized, double blinded cross-over design.

Exposure 1

Main characteristics
Frequency 2,140 MHz
Type
Polarization
Exposure duration continuous for 45 min
Additional info plane wave with vertical polarization
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 2.8 m
Chamber The study was performed under controlled conditions in a shielded 33.4 m³ climate chamber made of aluminium with walls, floor, and ceiling partly covered with RF absorbers. All cables to and from the chamber were filtered and mounted with ferrite beads to suppress common mode signals. All lighting in the room was from light-fibres or from a 12 V DC source, and all electronic devices were supplied by 12 V DC.
Setup The participants were seated on a chair at a wooden table next to a computer and keyboard.
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 2.2 V/m maximum measured - -
electric field strength 1.5 V/m minimum measured - limited area
electric field strength 0.9 V/m minimum measured - total area
power density 2.6 mW/m² - - - target value

Exposure 2

Main characteristics
Frequency 2,140 MHz
Type
Polarization
Exposure duration continuous for 45 min
Additional info plane wave with vertical polarization
Modulation
Modulation type cf. additional info
Additional info

a signal modulated as UMTS, or UMTS including all control features

Exposure setup
Exposure source
Distance between exposed object and exposure source 2.8 m
Additional info The CW modulated as UMTS was generated by setting the control channels to the lowest level (P-SCH, S-SCH, P-CCPCH, and the PICH channel). The UMTS signal was generated by initiating a live connection to a mobile phone through a 10 dB coupler and then filtering only the base station signal to the exposure antenna.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 2.2 V/m maximum measured - -
electric field strength 1.5 V/m minimum measured - limited area
electric field strength 0.9 V/m minimum measured - total area
power density 2.6 mW/m² - - - target value

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

No statistically significant differences between the UMTS and sham exposure were found in any of the cognitive tests or self reported symptoms in both adolescents and adults.

Study character:

Study funded by

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