Study type: Medical/biological study (experimental study)

902 MHz mobile phone does not affect short term memory in humans. med./bio.

Published in: Bioelectromagnetics 2004; 25 (6): 452-456

Aim of study (acc. to author)

To study the effects of an electromagnetic field as emitted by a 902 MHz mobile phone on human short term memory.

Background/further details

The study was a replication with methodological improvements (multi-centre testing and a double-blind study design) to a previous study (publication 4728). A total of 64 subjects in two independent laboratories performed a short term memory task.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 902 MHz
Modulation type: pulsed
Exposure duration: continuous for 65 min
  • SAR: 2.07 W/kg maximum
  • SAR: 0.99 W/kg average over mass (10 g)
  • power: 0.25 W mean

Exposure 1

Main characteristics
Frequency 902 MHz
Type
Exposure duration continuous for 65 min
Modulation
Modulation type pulsed
Pulse width 577 µs
Repetition frequency 217 Hz
Additional info

Discontinuous transmission mode was not activated.

Exposure setup
Exposure source
Distance between exposed object and exposure source 0.0337 m
Setup The mobile phone was mounted on the left side of the subject's head in the normal position of use with an adjustable rubber head cap. The antenna was located over the left posterior temporal lobe. The distance from the surface of the skull was measured in 12 randomly selected subjects, averaging 33.7 mm (SD 2.57 mm).
Additional info Each subject performed the tasks twice, once under the exposure to a mobile phone and once under a sham exposure. These sessions were separated by 24 ± 1 h. Both the subjects and the experimenters were unaware of the exposure condition (double blind).
Parameters
Measurand Value Type Method Mass Remarks
SAR 2.07 W/kg maximum measured - -
SAR 0.99 W/kg average over mass measured 10 g -
power 0.25 W mean - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

No statistically significant differences in performance between the two laboratories were found. The authors could not replicate the previous results: the electromagnetic field had no effect on reaction times or on the accuracy of the subjects' answers. The inability to replicate previous results could have been caused by lack of actual electromagnetic field effects or the magnitude of effects being at the sensitivity threshold of the test used.

Study character:

Study funded by

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