Study type: Medical/biological study (experimental study)

915 MHz microwaves and 50 Hz magnetic field affect chromatin conformation and 53BP1 foci in human lymphocytes from hypersensitive and healthy persons. med./bio.

Published in: Bioelectromagnetics 2005; 26 (3): 173-184

Aim of study (acc. to author)

To compare the effects of weak electromagnetic fields on lymphocytes from healthy donors and subjects with hypersensitivity to electromagnetic fields (1) and to study DNA breaks and apoptosis in electromagnetic field-exposed lymphocytes (2).

Background/further details

Heat shock (41°C for 2 h in a water bath) was used as a positive control for stress response. As a positive control for 53BP1 (tumor suppressor p53 binding protein 1; produces foci in response to DNA damage) foci formation and apoptosis, cells were irradiated with 137Cs γ rays (caesium gamma radiation), 3 Gy.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 2 h
Exposure 2: 915 MHz
Modulation type: pulsed
Exposure duration: continuous for 2 h
  • SAR: 37 mW/kg unspecified (unspecified)

General information

Samples from hypersensitive subjects and matched control subjects were simultaneously exposed.

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 2 h
Exposure setup
Exposure source
Setup Exposures were performed in 14 ml round bottom tubes at 22-23 °C with 2.5 ml of cell suspension per tube. The 50 Hz exposure unit has been previously described in the reference article. Briefly, it is based on three pairs of Helmholtz circular coils, which produce relatively homogenous (5% variation) magnetic field inside the working volume.
Additional info Control cells and sham exposed cells were kept under the same conditions as the exposed cells. As positive control for stress response, cells were kept in a water bath at 41°C for 2 h. As positive control for 53BP1 foci formation and apoptosis, the cells were irradiated with 3 Gy 137Cs γ rays at a dose rate of 10.6 Gy/min.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 15 µT peak value measured - vertical magnetic field
magnetic flux density 43.5 µT - measured - vertical static magnetic field

Exposure 2

Main characteristics
Frequency 915 MHz
Charakteristic
  • guided field
Exposure duration continuous for 2 h
Modulation
Modulation type pulsed
Additional info

Discontinuous transmission mode (DTX) was turned off.

Exposure setup
Exposure source
Setup The output of the mobile phone was connected by coaxial cable to a transverse electromagnetic transmission line cell (TEM cell) that has previously been described in the reference article. In principle, this is a spliced coaxial cable with a central electrode and an outer shield electrode with the unique characteristic of having both linear amplitude and phase response versus frequency.
Additional info The conditions for control and both positive controls were the same as described in E1.
Parameters
Measurand Value Type Method Mass Remarks
SAR 37 mW/kg unspecified measured and calculated unspecified -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Weak 50 Hz magnetic field and nonthermal mobile phone microwaves induced stress-like responses in lymphocytes smiliar but not identical to heat shock. These effects included changes in chromatin conformation and decreased level of 53BP1 foci. No significant difference in response was revealed between lymphocytes from hypersensitive and healthy subjects. No apoptosis was induced by exposure to 50 Hz and 915 Hz.

Study character:

Study funded by

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