Study type: Medical/biological study (experimental study)

In vitro increase of the fluid-phase endocytosis induced by pulsed radiofrequency electromagnetic fields: importance of the electric field component med./bio.

By: Mahrour N, Pologea-Moraru R, Moisescu MG, Orlowski S, Leveque P, Mir LM
Published in: Biochim Biophys Acta Biomembr 2005; 1668 (1): 126-137
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Aim of study (acc. to author)

To study the effects of mobile phones electromagnetic fields or its pure, low-frequency pulsed electric field component on fluid-phase endocytosis.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: pulsed
Exposure duration: continuous for 10 min
Exposure 2: 900 MHz
Modulation type: CW
Exposure duration: continuous for 10 min
Exposure 3: 50–400 MHz
Modulation type: pulsed
Exposure duration: 5 min - 90 min

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Exposure duration continuous for 10 min
Modulation
Modulation type pulsed
Pulse width 580 µs
Duty cycle 12.5 %
Repetition frequency 217 Hz
Exposure setup
Exposure source
  • wire patch antenna 15 cm x 15 cm x 2.9 cm
Setup The magnetic field component was parallel to the plates of the wire patch antenna and had an orthoradial symmetry around the wire, while the electric field component was parallel to the wire, and normal to the plates. A fair homogeneity of the EMF was achieved for the whole of the exposed cell populations.
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 1 W minimum - - incident power
power 7 W maximum - - incident power
SAR 0.65 W/kg mean measured and calculated - for 1 W
SAR 5.2 W/kg peak value measured and calculated - for 1 W
Measurement and calculation details

Due to the good matching of the antenna, reflected power (measured with a wattmeter via a circulator) remained negligible compared to the incident power when the Petri dishes were correctly placed in the antenna. The theoretical calculations of SAR distribution (SAR = σE²/ρ) were validated experimentally using local probes for electric field and thermal elevation.

Exposure 2

Main characteristics
Frequency 900 MHz
Type
Exposure duration continuous for 10 min
Modulation
Modulation type CW
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 1 W minimum - - incident power
power 56 W maximum - - incident power
SAR 0.65 W/g mean measured and calculated - for 1 W incident power
SAR 5.2 W/g peak value measured and calculated - for 1 W incident power

Exposure 3

Main characteristics
Frequency 50–400 MHz
Type
Waveform
  • rectangular
Exposure duration 5 min - 90 min
Modulation
Modulation type pulsed
Pulse type biphasic
Additional info

pulse width: 75 µs - 500 µs
Exposure setup
Exposure source
  • two parallel Pt/Ir rods inserted into the dishes as electrodes with 4 cm distance
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 1.2 V/cm minimum measured - -
electric field strength 8 V/cm maximum measured - -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

For the three cell lines, an increased fluid-phase endocytosis was revealed. This increase is an all-or-nothing type of response that is occurring for threshold values comprised between 1.3 and 2.6 W/kg for the delivered electromagnetic field powers and between 1.1 and 1.5 V/cm for the electric field intensities. The electric component of these electromagnetic fields is shown to be responsible for the revealed increase. Variations of frequency or pulse duration of the electric pulses are without effect.
In conclusion, electromagnetic fields, via their electrical component, can perturb one of the most fundamental physiological functions of the cells-endocytosis.

Study character:

Study funded by

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