Study type: Medical/biological study (experimental study)

Micronucleus frequency in erythrocytes of mice after long-term exposure to radiofrequency radiation. med./bio.

Published in: Int J Radiat Biol 2007; 83 (4): 213-220

Aim of study (acc. to author)

To study genotoxicity of long-term exposure to radiofrequency electromagnetic fields by measuring of micronuclei formation in erythrocytes. Two animal studies evaluating possible cocarcinogenic effects of radiofrequency electromagnetic fields were performed.

Background/further details

Study 1: Female CBA/S mice were exposed for 78 weeks to either a continuous signal similar to that emitted by analog NMT mobile phones (at 1.5 W/kg; n = 20) or to a pulsed signal similar to that of digital GSM mobile phones (at 0.35 W/kg; n = 20). A third group was sham exposed (n = 20), and a fourth group served as cage controls (n = 19). All but the cage control mice were exposed to 4 Gy of x-rays during the three first weeks of the experiment.
Study 2: Female transgenic mice (line K2; n = 20) and their non-transgenic littermates (n = 20) were exposed for 52 weeks. Two digital mobile phone signals, GSM and D-AMPS were used at 0.5 W/kg. All but the cage control mice (n = 14) were exposed 3 times per week to an ultraviolet radiation dose of 1.2 MED (minimum erythema dose; i.e. 240 J/m²).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 902.5 MHz
Modulation type: CW
Exposure duration: repeated daily exposure, 1.5 h/day, 5 days/week, for 78 weeks
  • SAR: 1.5 W/kg average over time (whole body) ([Heikkinen et al., 2001])
Exposure 2: 902.4 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure, 1.5 h/day, 5 days/week, for 78 weeks
  • SAR: 0.35 W/kg average over time (whole body) ([Heikkinen et al., 2001])
Exposure 3: 902.4 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure, 1.5 h/day, 5 days/week, for 52 weeks
  • SAR: 0.5 W/kg average over time (whole body) ([Heikkinen et al., 2001])
Exposure 4: 849 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure, 1.5 h/day, 5 days/week, for 52 weeks
  • SAR: 0.5 W/kg average over time (whole body) ([Heikkinen et al., 2001])

Exposure 1

Main characteristics
Frequency 902.5 MHz
Type
Charakteristic
  • guided field
Exposure duration repeated daily exposure, 1.5 h/day, 5 days/week, for 78 weeks
Additional info NMT analog mobile phone
Modulation
Modulation type CW
Exposure setup
Exposure source
Chamber Three identical rectangular waveguide chambers made of aluminium were used for the two RF radiation exposure groups and the sham-exposed group. Exposure of 25 mice at a time was possible in one chamber. The exposure system was described in [Heikkinen et al., 2001].
Setup The mice were kept in small cylindrical acrylic restrainers (inner diameter 32 mm, length adjustable) placed on a Styrofoam holder in the center of the cross section of the waveguide with their longitudinal axes perpendicular to the EF and to the direction of propagation.
Sham exposure A sham exposure was conducted.
Additional info The output power was absorbed by a coaxial 10 W termination in both RF-exposure chambers.
Parameters
Measurand Value Type Method Mass Remarks
SAR 1.5 W/kg average over time determined by power loss whole body [Heikkinen et al., 2001]

Exposure 2

Main characteristics
Frequency 902.4 MHz
Type
Charakteristic
  • guided field
Exposure duration repeated daily exposure, 1.5 h/day, 5 days/week, for 78 weeks
Additional info GSM mobile phone
Modulation
Modulation type pulsed
Pulse width 0.577 ms
Repetition frequency 217 Hz
Additional info

Speech modulation was simulated using a random sequence of bytes.

Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.35 W/kg average over time determined by power loss whole body [Heikkinen et al., 2001]

Exposure 3

Main characteristics
Frequency 902.4 MHz
Type
Charakteristic
  • guided field
Exposure duration repeated daily exposure, 1.5 h/day, 5 days/week, for 52 weeks
Additional info GSM mobile phone
Modulation
Modulation type pulsed
Pulse width 0.577 ms
Repetition frequency 217 Hz
Additional info

Speech modulation was simulated using a random sequence of bytes.

Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.5 W/kg average over time determined by power loss whole body [Heikkinen et al., 2001]

Exposure 4

Main characteristics
Frequency 849 MHz
Type
Charakteristic
  • guided field
Exposure duration repeated daily exposure, 1.5 h/day, 5 days/week, for 52 weeks
Additional info DAMPS mobile phone
Modulation
Modulation type pulsed
Pulse width 6.67 ms
Repetition frequency 50 Hz
Additional info

Speech modulation was simulated using a random sequence of bytes.

Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.5 W/kg average over time determined by power loss whole body [Heikkinen et al., 2001]

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The data did not show any effects of radiofrequency electromagnetic fields on micronucleus frequency in erythrocytes. The findings were consistent in two mouse strains (and in a transgenic variant of the second strain), after 52 or 78 weeks of irradiation, at three SAR levels relevant to human exposure from mobile phones, and for three different mobile phone signals.

Study character:

Study funded by

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