Study type: Medical/biological study (experimental study)

No short-term effects of high-frequency electromagnetic fields on the mammalian pineal gland. med./bio.

Published in: Bioelectromagnetics 1997; 18 (5): 376-387

Aim of study (acc. to author)

To study whether short-term exposure to electromagnetic fields of 900 MHz has demonstrable effects on the pineal gland.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: CW
Exposure duration: continuous for 15, 30, or 60 min
Exposure 2: 900 MHz
Modulation type: pulsed
Exposure duration: continuous for 15, 30, or 60 min and 2, 4, or 6 h
Exposure 3: 900 MHz
Modulation type: pulsed
Exposure duration: continuous for 6 h
Exposure 4: 900 MHz
Modulation type: pulsed
Exposure duration: continuous for 90 min

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Polarization
  • circular
Exposure duration continuous for 15, 30, or 60 min
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 385 mm
Chamber The ventilated exposure box, made of plywood and covered with a hood, was completely shielded on the outside with an 0.1-mm aluminium foil and covered on the inside with flat absorber material. The box consisted of two compartments separated by a glass plate. The lower one contained the antenna, and the upper one received the polystyrene cage of 0.37 x 0.24 x 0.175 cm with three animals inside.
Setup The antenna in the first box produced a left-hand polarized field in the main radiation direction, i.e., the antenna axis. For simultaneous and sham exposure, an additional exposure box with a right-hand polarized antenna was used. The boxes were randomly selected for real and sham exposures.
Sham exposure A sham exposure was conducted.
Additional info In the first 12 experiments, real and sham exposures had to be carried out sequentially since only one box was available. In the following experiments (13-26), real and sham exposures were carried out simultaneously.
Parameters
Measurand Value Type Method Mass Remarks
power density 0.1 mW/cm² mean measured - -
SAR 0.06 W/kg - estimated - in rats

Exposure 2

Main characteristics
Frequency 900 MHz
Type
Polarization
  • circular
Exposure duration continuous for 15, 30, or 60 min and 2, 4, or 6 h
Modulation
Modulation type pulsed
Repetition frequency 217 Hz
Additional info

GSM standard

Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power density 0.1 mW/cm² mean measured - -
SAR 0.06 W/kg - estimated - in rats
SAR 0.04 W/kg - estimated - in Djungarian hamsters, exposed for 2 h only

Exposure 3

Main characteristics
Frequency 900 MHz
Type
Polarization
  • circular
Exposure duration continuous for 6 h
Modulation
Modulation type pulsed
Repetition frequency 217 Hz
Additional info

GSM standard

Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power density 0.4 mW/cm² mean measured - -
SAR 0.24 W/kg - estimated - in rats

Exposure 4

Main characteristics
Frequency 900 MHz
Type
Polarization
  • circular
Exposure duration continuous for 90 min
Modulation
Modulation type pulsed
Repetition frequency 217 Hz
Additional info

GSM standard

Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power density 0.6 mW/cm² mean measured - -
SAR 0.36 W/kg - estimated - in rats

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)

Both continuous and/or pulsed microwaves at day or night had no notable short-term effect on pineal melatonin synthesis in Sprague-Dawley rats and Djungarian hamsters. Pineal synaptic ribbon profile numbers were likewise not affected.
The 900 MHz electromagnetic fields, unpulsed or pulsed, have no short-term effect on the mammalian pineal gland.

Study character:

Study funded by

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