Study type: Medical/biological study (experimental study)

Effects of 900 MHz electromagnetic fields exposure on cochlear cells' functionality in rats: Evaluation of distortion product otoacoustic emissions med./bio.

By: Galloni P, Lovisolo GA, Mancini S, Parazzini M, Pinto R, Piscitelli M, Ravazzani P, Marino C
Published in: Bioelectromagnetics 2005; 26 (7): 536-547
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Aim of study (acc. to author)

To evaluate the possible effects of cellular phone-like emissions on the functionality of rat's cochlea.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 936 MHz
Modulation type: CW
Exposure duration: repeated daily exposure for 3 h per day for 5 days
  • SAR: 1 W/kg average over mass (whole body)
Exposure 2: 923 MHz
Modulation type: CW
Exposure duration: repeated daily exposure for 3 h per day for 5 days
  • SAR: 1 W/kg average over mass (partial body)
Exposure 3: 960 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure for 3 h per day for 5 days
  • SAR: 1 W/kg average over mass
Exposure 4: 900 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure for 2 h per day for 5 days per week for 4 weeks
  • SAR: 2 W/kg average over mass

General information

During the treatment the rats were inserted in Perspex jigs, which were cylindrical tubes with a cone-shaped head end and a lockable piston in the tail end to prevent rats from backing out of the restrainer. This assembly was able to keep them as motionless as possible and at the same time cause minimal restrain stress.

Exposure 1

Main characteristics
Frequency 936 MHz
Type
Charakteristic
Exposure duration repeated daily exposure for 3 h per day for 5 days
Modulation
Modulation type CW
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 1 W/kg average over mass measured and calculated whole body -

Exposure 2

Main characteristics
Frequency 923 MHz
Type
Charakteristic
Exposure duration repeated daily exposure for 3 h per day for 5 days
Modulation
Modulation type CW
Exposure setup
Exposure source
Setup antennas have been built using the coplanar line technique on a dielectric substrate; line terminated with a rectangular loop printed on the substrate; electromagnetic matching with the power supply is done using an electric contact sliding on the substrate
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 1 W/kg average over mass measured and calculated partial body -
Measurement and calculation details

Numerical simulations of the local SAR in tissues have been performed using a commercial code (XFDTD code) on a realistic model of rat head; with the fundamental tissues (skin, fat, muscle, brain, bone), while measurements have been carried out with miniaturized probes on homogenous phantoms (brain equivalent tissue) and in the inner ear of a rat's cadaver. The measures in the sacrificed rat have been performed by power pulse method using an electronic thermometer and a fiberoptic probe. Data from numerical and experimental dosimetry showed a good agreement.

Exposure 3

Main characteristics
Frequency 960 MHz
Type
Charakteristic
Exposure duration repeated daily exposure for 3 h per day for 5 days
Modulation
Modulation type pulsed
Exposure setup
Exposure source
  • same as E2
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 1 W/kg average over mass measured and calculated - -

Exposure 4

Main characteristics
Frequency 900 MHz
Type
Charakteristic
Exposure duration repeated daily exposure for 2 h per day for 5 days per week for 4 weeks
Modulation
Modulation type pulsed
Exposure setup
Exposure source
  • same as E2
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 2 W/kg average over mass measured and calculated - -

Reference articles

  • Marino C et al. (2000): Effects of microwaves (900 MHz) on the cochlear receptor: exposure systems and preliminary results
  • Chou CK et al. (1999): Development of a rat head exposure system for simulating human exposure to RF fields from handheld wireless telephones

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • before exposure
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

No significant difference due to exposure to microwaves has been evidenced (no changes in the otoacoustic emission parameters).

Study character:

Study funded by

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