Study type: Medical/biological study (experimental study)

Possible Combined Effects of 900 MHz Continuous-Wave Electromagnetic Fields and Gentamicin on the Auditory System of Rats. med./bio.

Published in: Radiat Res 2007; 167 (5): 600-605

Aim of study (acc. to author)

To evaluate the cochlear functionality of rats exposed to electromagnetic fields at 900 MHz and to gentamicin (loss of hearing or balance is a well-documented adverse effect of such aminoglycoside antibiotics).

Background/further details

32 rats were divided into four groups: group 1 was treated with daily intramuscular injections of gentamicin for 15 days (150 mg/kg); group 2 was treated with daily intramuscular injections of gentamicin for 15 days (same dose) and exposed to electromagnetic fields; group 3 was exposed to electromagnetic fields; group 4 was sham-exposed.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: CW
Exposure duration: repeated daily exposure, 2 h/day, 5 days/week, for 4 weeks

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Exposure duration repeated daily exposure, 2 h/day, 5 days/week, for 4 weeks
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 10 mm
Chamber The exposure system consisting of three distinct arrays of four loop antennas to expose 12 rats simultaneously was assembled in a wooden rack with RF absorbing panels on the four sides and between the levels [Galloni et al., 2005]. The arrays were used simultaneously, two for real and one for sham exposure, and were connected (blinded) to the MW generator through a black box.
Setup Rats were individually restrained in cylindrical Perspex tubes with a cone-shaped head end. The antenna was held in contact with the tube perpendicular to the head surface over the right ear of the rat at a total distance of about 8-10 mm from the cochlea (localised exposure).
Sham exposure A sham exposure was conducted.
Additional info Rats were placed close to a different antenna (in the same array) each day to ensure a uniform distribution of exposure. The antennas were rectangular loops printed on dielectric substrate using the coplanar line technique [Leveque et al., 2004].
Parameters
Measurand Value Type Method Mass Remarks
SAR 4 W/kg - measured and calculated - -

Reference articles

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)

The data showed no evidence of a combined effect of a radiofrequency electromagnetic field exposure and gentamicin on the auditory system of rats under these experimental conditions.

Study character:

Study funded by

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