Study type: Medical/biological study (experimental study)

ROS release and Hsp70 expression after exposure to 1,800 MHz radiofrequency electromagnetic fields in primary human monocytes and lymphocytes. med./bio.

Published in: Radiat Environ Biophys 2006; 45 (1): 55-62

Aim of study (acc. to author)

To study if 1800 MHz radiofrequency electromagnetic fields can induce reactive oxygen species release and/or changes in heat shock protein 70 expression (to determine a possible inhibitor effect on free radical release) in human blood cells.

Background/further details

Human umbilical cord blood-derived monocytes and lymphocytes were used to examine reactive oxygen species release (cell stimulation with the phorbol ester tetradecanoylphorbol acetate (TPA) was used as positive control). To study HSP70 expression human monocytes were exposed (heat treatment at 42°C was used as positive control).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1,800 MHz
Modulation type: CW
Exposure duration: continuous or intermittent (5 min on/off) for 30 or 45 min
Exposure 2: 1,800 MHz
Modulation type: pulsed
Exposure duration: continuous or intermittent (5 min on/off) for 30 or 45 min
Exposure 3: 1,800 MHz
Modulation type: pulsed
Exposure duration: continuous or intermittent (5 min on/off) for 30 or 45 min

General information

The cells were exposed to CW or different GSM signals (GSM-DTX, GSM-Talk), as described previously [Lantow et al., 2006].

Exposure 1

Main characteristics
Frequency 1,800 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous or intermittent (5 min on/off) for 30 or 45 min
Modulation
Modulation type CW
Exposure setup
Exposure source
Chamber Two single-mode resonator cavities were placed within an incubator at 37°C (except heat-treatment) in a humidified atmosphere of 5% CO2 in air. Exposure and sham conditions were blindly and randomly assigned to the two waveguides by the computer-controlled signal unit [Schuderer et al., 2004].
Setup Six 35 mm Petri dishes were placed in each waveguide on a dish holder, and in the H-field maxima of the standing waves inside the cavity. The temperature difference between sham and RF exposed cultures was not greater than 0.3°C.
Sham exposure A sham exposure was conducted.
Additional info The cells were exposed in parallel and in the same incubator to the following conditions: (1) non-treated (incubator control), (2) sham exposed, (3) RF-EMF exposed, (4) sham exposed + 1 µM PMA, (5) co-exposed to RF-EMF + PMA, (6) heat exposed at 42°C for 1 h.
Parameters
Measurand Value Type Method Mass Remarks
SAR 2 W/kg - measured and calculated - -

Exposure 2

Main characteristics
Frequency 1,800 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous or intermittent (5 min on/off) for 30 or 45 min
Additional info GSM-DTX
Modulation
Modulation type pulsed
Repetition frequency 217 Hz
Additional info

GSM-DTX (hearing only): 12 active frames per 104 frames, crest factor of 69, frame structure 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 2 W/kg - measured and calculated - -

Exposure 3

Main characteristics
Frequency 1,800 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous or intermittent (5 min on/off) for 30 or 45 min
Additional info GSM-Talk
Modulation
Modulation type pulsed
Repetition frequency 217 Hz
Additional info

GSM-Talk (34% speaking and 66% hearing): temporal changes between 11 s non-DTX and 6 s DTX (average durations); crest factor of 11.9.

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

Reference articles

  • Lantow M et al. (2006): Free radical release and HSP70 expression in two human immune-relevant cell lines after exposure to 1800 MHz radiofrequency radiation.
  • Schuderer J et al. (2004): High Peak SAR Exposure Unit With Tight Exposure and Environmental Control for In Vitro Experiments at 1800 MHz

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated material:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The TPA treatment induced a significant increase in reactive oxygen species production in monocytes and lymphocytes compared to sham-exposed or to incubator controls. After continuous or intermittent GSM-DTX signal exposure (2 W/kg), a significantly different reactive oxygen species production was detected in monocytes compared to sham-exposed cells. However, this significant difference appeared due to the lowered value of reactive oxygen species during sham exposure. In lymphocytes, no differences could be revealed if data were compared either to sham-exposed or to incubator control.
The HSP70 expression level after 0, 1, and 2 h post-exposure to GSM-DTX signal at 2 W/kg for 1 h did not show any differences compared to the incubator or to sham-exposed control.

Study character:

Study funded by

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