Study type: Medical/biological study (experimental study)

Effect of 900 MHz electromagnetic fields on nonthermal induction of heat-shock proteins in human leukocytes. med./bio.

Published in: Radiat Res 2005; 163 (1): 45-52

Aim of study (acc. to author)

To study whether exposure to mobile phone-type irradiation causes a nonthermal stress response in human leukocytes.

Background/further details

Positive (heat-stressed at 42°C) and negative (kept at 37°C) control samples were incubated simultaneously.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: CW
Exposure duration: continuous for 4 hours
This study was performed to investigate the effects of different power levels.
  • SAR: 0.4 W/kg mean (unspecified) (input power level of 3 W)
  • SAR: 2 W/kg mean (unspecified) (input power level of 14 W)
  • SAR: 3.6 W/kg mean (unspecified) (input power level of 25 W)
Exposure 2: 900 MHz
Modulation type: CW
Exposure duration: continuous for 20 min, 1 h or 4 h
This study was performed to investigate the effects of different exposure durations.
Exposure 3: 900 MHz
Modulation type: pulsed
Exposure duration: continuous for 20 min, 1 h or 4 h
This study was performed to investigate the effects of different exposure durations using a GSM signal.

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Exposure duration continuous for 4 hours
Additional info This study was performed to investigate the effects of different power levels.
Modulation
Modulation type CW
Exposure setup
Exposure source
Setup The human peripheral blood was exposed or sham-exposed in Petri dishes in a calibrated TEM cell placed in an incubator. The cell was operated in travelling wave mode, being terminated by a matched load, which increased the uniformity of the exposure.
Additional info Positive (heat-stressed at 42°C) and negative (kept at 37°C) control groups were incubated simultaneously in the same incubator. The sham-exposed dish and the positive control were heated by heater mats, the negative control was in equilibrium with the incubator temperature. The peak static magnetic flux density generated by the heater mat and measured 2 mm above the mat using an incremental gaussmeter was below 15 µT.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.4 W/kg mean measured and calculated unspecified input power level of 3 W
SAR 2 W/kg mean measured and calculated unspecified input power level of 14 W
SAR 3.6 W/kg mean measured and calculated unspecified input power level of 25 W

Exposure 2

Main characteristics
Frequency 900 MHz
Type
Exposure duration continuous for 20 min, 1 h or 4 h
Additional info This study was performed to investigate the effects of different exposure durations.
Modulation
Modulation type CW
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 2 W/kg mean calculated unspecified -

Exposure 3

Main characteristics
Frequency 900 MHz
Type
Exposure duration continuous for 20 min, 1 h or 4 h
Additional info This study was performed to investigate the effects of different exposure durations using a GSM signal.
Modulation
Modulation type pulsed
Duty cycle 12.5 %
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.4 W/kg mean calculated unspecified -

Reference articles

  • Lim HB et al. (2002): FDTD design of RF dosimetry apparatus to quantify the effects of near fields from mobile handsets on stress response mechanisms of human whole blood

Methods Endpoint/measurement parameters/methodology

Investigated material:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Heat caused an increase in the number of cells expressing stress proteins (HSP70, HSP27) and this increase was dependent on time. However, no statistically significant difference was detected in the number of cells expressing stress proteins after exposure. These data suggest that mobile phone-type irradiation is not a stressor of normal human lymphocytes and monocytes, in contrast to mild heating.

Study character:

Study funded by

Related articles