Study type: Medical/biological study (experimental study)

Pulsed and continuous wave mobile phone exposure over left versus right hemisphere: effects on human cognitive function. med./bio.

Published in: Bioelectromagnetics 2007; 28 (4): 289-295

Aim of study (acc. to author)

To assess the effects of both continuous wave and pulsed wave electromagnetic fields on human cognitive function as measured by behavioral tests in 36 healthy male subjects. The subjects performed the same tasks twice during each session; once with left-sided and once with right-sided exposure.

Background/further details

The same cognitive tasks that were used in previous studies were employed (see publication 12332, publication 11186, publication 9851, publication 3601, and publication 4728).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 902 MHz
Modulation type: CW
Exposure duration: continuous for approx. 90 min
  • power: 0.25 W mean
  • SAR: 0.738 W/kg average over mass (10 g)
  • SAR: 1.1 W/kg average over mass (1 g)
  • SAR: 1.18 W/kg peak value
Exposure 2: 902 MHz
Modulation type: pulsed
Exposure duration: continuous for approx. 90 min
  • power: 0.25 W mean
  • SAR: 0.738 W/kg average over mass (10 g)
  • SAR: 1.1 W/kg average over mass (1 g)
  • SAR: 1.18 W/kg peak value

General information

Each subject participated in three sessions (CW, PM, and sham exposure), separated by 1 week. The tasks were performed twice during each session, once with left-sided and once with right-sided exposure. The exposed hemisphere, EMF condition, and test order were counterbalanced over all subjects, and a double-blind design was employed. An additional control group performed the same tasks without any exposure equipment.

Exposure 1

Main characteristics
Frequency 902 MHz
Type
Exposure duration continuous for approx. 90 min
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 20 mm
Chamber The subjects were seated on a desk chair approx. 1 m from a computer screen. The signal generator and the power amplifier were located in an adjacent room.
Setup The dummy mobile phone was attached to the subject's head using an earmuff without metal parts, in which one of the protectors was replaced. The phone was positioned as in normal use. The antenna was located approx. 20 mm from the scalp over the posterior temporal lobe in the left-side exposure, and over the inferior and posterior temporal lobe in the right-side exposure. The difference between hemispheres was due to the asymmetrical position of the antenna.
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 0.25 W mean measured - -
SAR 0.738 W/kg average over mass measured 10 g -
SAR 1.1 W/kg average over mass measured 1 g -
SAR 1.18 W/kg peak value measured - -

Exposure 2

Main characteristics
Frequency 902 MHz
Type
Exposure duration continuous for approx. 90 min
Modulation
Modulation type pulsed
Pulse width 0.577 ms
Repetition frequency 217 Hz
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power 0.25 W mean measured - -
SAR 0.738 W/kg average over mass measured 10 g -
SAR 1.1 W/kg average over mass measured 1 g -
SAR 1.18 W/kg peak value measured - -

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 effects were found between the different electromagnetic field conditions, separate hemisphere exposures, or between the control (n=16) and experimental exposed group. The data indicate that normal mobile phones have no discernible effect on human cognitive function.

Study character:

Study funded by

Related articles