Study type: Medical/biological study (experimental study)

1800 MHz radiofrequency (mobile phones, different Global System for Mobile communication modulations) does not affect apoptosis and heat shock protein 70 level in peripheral blood mononuclear cells from young and old donors. med./bio.

Published in: Int J Radiat Biol 2004; 80 (6): 389-397

Aim of study (acc. to author)

To investigate if prolonged in vitro exposure to 1800 MHz radiofrequency could exert an effect on human peripheral blood mononuclear cells from young and elderly donors by affecting apoptosis, mitochondrial membrane potential (a parameter highly correlated with the apoptotic process) and heat shock protein (HSP 70) levels. Endpoints were examined in the presence or absence of the apoptosis-inducing agent 2-deoxy-D-ribose.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1,800 MHz
Modulation type: pulsed
Exposure duration: intermittent, 10 min on/20 min off, for 44 h
  • SAR: 2 W/kg average over time (16.6 W/kg slot average)
Exposure 2: 1,800 MHz
Modulation type: pulsed
Exposure duration: intermittent, 10 min on/20 min off, for 44 h
  • SAR: 1.4 W/kg average over time (97.1 W/kg slot average)
Exposure 3: 1,800 MHz
Modulation type: pulsed
Exposure duration: intermittent, 10 min on/20 min off, for 44 h
  • SAR: 2 W/kg average over time (23.7 W/kg slot average)

Exposure 1

Main characteristics
Frequency 1,800 MHz
Type
Charakteristic
  • guided field
Exposure duration intermittent, 10 min on/20 min off, for 44 h
Additional info GSM Basic
Modulation
Modulation type pulsed
Pulse width 0.576 ms
Duty cycle 12.5 %
Repetition frequency 217 Hz
Pulse type rectangular
Additional info

GSM Basic signal with every 26th frame of the basic TDMA frame being idle (adding an 8-Hz modulation component)

Exposure setup
Exposure source
Chamber The exposure set-up consisted of two single-mode resonator cavities equipped with a fan and field sensors and placed within a CO2 incubator. Exposure and sham conditions were blindly assigned to the two waveguides by the computer-controlled signal unit. Field strengths, temperatures and fan currents as well as all commands were continuously logged. The difference in air temperature between the exposed and sham waveguide monitored with accurate Pt100 probes was less than 0.1°C.
Setup Six 35-mm Petri dishes were exposed in each waveguide resonator with a dish holder placing them exactly in the H-field maximum of the standing wave. The system enabled the exposure of monolayers of cells with a non-uniformity of SAR of less than 30% (SD).
Sham exposure A sham exposure was conducted.
Additional info Sham and RF exposures were performed immediately after cell seeding with or without dRib treatment. The maximum temperature load for the exposed cells due to absorption was below 0.04°C. Simulations of the temperature distribution in the Petri dish showed that hot spots in the cell medium could be excluded.
Parameters
Measurand Value Type Method Mass Remarks
SAR 2 W/kg average over time measured and calculated - 16.6 W/kg slot average

Exposure 2

Main characteristics
Frequency 1,800 MHz
Type
Charakteristic
  • guided field
Exposure duration intermittent, 10 min on/20 min off, for 44 h
Additional info GSM DTX
Modulation
Modulation type pulsed
Pulse width 0.576 ms
Duty cycle 12.5 %
Repetition frequency 217 Hz
Pulse type rectangular
Additional info

GSM DTX signal (active during periods without speaking) with transmission being reduced to 12 frames per 104 frame intermediate multiframe (resulting in 2-, 8- and 217-Hz components)

Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 1.4 W/kg average over time measured and calculated - 97.1 W/kg slot average

Exposure 3

Main characteristics
Frequency 1,800 MHz
Type
Charakteristic
  • guided field
Exposure duration intermittent, 10 min on/20 min off, for 44 h
Additional info GSM Talk
Modulation
Modulation type pulsed
Pulse width 0.576 ms
Duty cycle 12.5 %
Repetition frequency 217 Hz
Pulse type rectangular
Additional info

GSM Talk signal simulating a conversation and generating temporal changes between 50 s of GSM Basic and 97 s of GSM DTX (average durations)

Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 2 W/kg average over time measured and calculated - 23.7 W/kg slot average

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated material:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

In all conditions and for all endpoints studied, there was no significant difference between irradiated and sham-exposed cells. 1800 MHz radiofrequency could not induce apoptosis by itself or affect the apoptotic phenomenon when induced by an apoptotic agent. Moreover, radiofrequency exposure did not modify the mitochondrial functionality and the expression of HSP 70.

Study character:

Study funded by

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