Medical/biological study (experimental study)

Is the effect of mobile phone radiofrequency waves on human skin perfusion non-thermal? med./bio.

By: Loos N, Gyorgy T, Ghosn R, Brenet-Dufour V, Liabeuf S, Selmaoui B, Jean-Pierre L, Bach V, Diouf M, de Seze R

Published in: Microcirculation 2013; 20 (7): 629-636

Aim of study (acc. to author)

To study whether skin microcirculation can be modified by exposure to the radiofrequency fields emitted by a mobile phone hold to the jaw and ear.

Background/further details

20 volunteers participated (12 women, 8 men; 25 ± 3.9 years). The exposure and sham exposure sessions were performed in random order.
A heat challenge was performed 25 minutes after the end of exposure by locally heating both sides of the face to 44°C for 1 minute, followed by a 30 minute period for the return to baseline. This hyperthermia induced local hyperaemia, which reflects the skin microvessels' ability to dilate in response to heating.

Endpoint

microcirculation and temperature changes in the skin

Exposure

- PW pulsed wave
- mobile communications
- mobile phone
- GSM

Exposure	Parameters
Exposure 1: 900 MHz Modulation type: pulsed Exposure duration: continuous for 20 min	power: 2 W peak value power: 250 mW mean SAR: 0.49 W/kg maximum (10 g)

Exposure 1

Main characteristics

Frequency	900 MHz
Type	electromagnetic field
Exposure duration	continuous for 20 min

Modulation

Modulation type	pulsed
Duty cycle	12.5 %

Exposure setup

Exposure source	cellular phone Nokia 6650
Setup	"radiofrequency" or "sham" mobile phone was positioned against the left ear (using a helmet-like holder); phone was placed with its long axis aligned from the opening of the ear canal to the corner of the mouth
Sham exposure	A sham exposure was conducted.
Additional info	room temperature was kept constant at 24 ± 0.6°C

Parameters

Measurand	Value	Type	Method	Mass	Remarks
power	2 W	peak value	-	-	-
power	250 mW	mean	-	-	-
SAR	0.49 W/kg	maximum	measured and calculated	10 g	-

Measurement and calculation details

specific absorption rate was measured with a phantom filled with standard brain tissue-equivalent liquid

Exposed system:

human
partial body: jaw and ear

Methods Endpoint/measurement parameters/methodology

microcirculation and temperature changes in the skin (at both sides of the face; laser-Doppler flowmetry)

Investigated system:

investigation on living organism

Investigated organ system:

Time of investigation:

before exposure
during exposure
after exposure

Main outcome of study (acc. to author)

For a given side of the face, the radiofrequency exposure and sham exposure sessions did not differ significantly in terms of the skin microcirculation (according to the results). According to the abstract and discussion however, skin microcirculation increased more during the radiofrequency exposure session (vs. baseline) than during the sham exposure. The sessions (exposure vs. sham exposure) did not differ significantly in terms of the skin temperature time-course response.
When heating the skin locally to 44°C (on both sides of the face at the same time), the early peak value of skin microcirculation (i.e. the raw data after 1 minute) on the exposed side of the face was significantly greater after the radiofrequency exposure session than after the sham exposure session, i.e. the skin microvessels' vasodilatory ability was greater.
The authors conclude, that the data reveal the existence of a specific vasodilatory effect of mobile phone radiofrequency emission on skin perfusion.

Study character:

medical/biological study
experimental study
full/main study
double-blind study

Study funded by

not stated/no funding

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Ghosn R et al. (2012): Effects of GSM 900 MHz on middle cerebral artery blood flow assessed by transcranial Doppler sonography
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Adair ER et al. (2001): Partial-body exposure of human volunteers to 2450 MHz pulsed or CW fields provokes similar thermoregulatory responses
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Bernardi P et al. (2000): Specific absorption rate and temperature increases in the head of a cellular-phone user
Adair ER et al. (1999): Human exposure at two radio frequencies (450 and 2450 MHz): similarities and differences in physiological response