Study type: Medical/biological study (experimental study)

Mobile phone affects cerebral blood flow in humans. med./bio.

Published in: J Cereb Blood Flow Metab 2006; 26 (7): 885-890

Aim of study (acc. to author)

To study the effects of a mobile phone on regional cerebral blood flow in 12 healthy humans during exposure to electromagnetic field, while performing a verbal working memory task.

Background/further details

A substantially more sensitive experimental design (concerning the exposure) than in a previous study (publication 10384) was used.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 902 MHz
Modulation type: pulsed
Exposure duration: 51 mins
  • SAR: 1.51 W/kg peak value
  • SAR: 0.743 W/kg average over mass (10 g)

Exposure 1

Main characteristics
Frequency 902 MHz
Type
Waveform
Exposure duration 51 mins
Modulation
Modulation type pulsed
Pulse width 0.577 ms
Repetition frequency 217 Hz
Additional info

Discontinuous mode was not activated.

Exposure setup
Exposure source
Distance between exposed object and exposure source 17 mm
Setup The phone was placed between the subject`s head and the head rest of a positron emission tomography (PET) scanner parallel to the medial plane. The antenna was located circa 17 mm from the surface of the skull over the subject`s left inferior temporal lobe.
Sham exposure A sham exposure was conducted.
Additional info In order to eliminate audio clues the phone`s loudspeaker was removed and its battery was removed. It was operated with an external power source located 3 m away. The subjects were asked to insert an ear plug into the left ear. The EMF/sham exposure was started at the same moment as the transmission scan. After a 9 min transmission scan, each subject was scanned 14 times, out of which the first or the last seven scans were obtained during a constant EMF or sham exposure.
Parameters
Measurand Value Type Method Mass Remarks
SAR 1.51 W/kg peak value measured - -
SAR 0.743 W/kg average over mass measured 10 g -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The data suggest that the electromagnetic field emitted by a mobile phone affects regional cerebral blood flow in humans. The results revealed that a mobile phone in operation induces a local decrease in regional cerebral blood flow beneath the antenna in the inferior temporal cortex and an increase more distantly in the prefrontal cortex.
The electromagnetic field had no effects on reaction times or the accuracy of responses in the working memory task.

Study character:

Study funded by

Related articles