Study type: Medical/biological study (experimental study)

1800 MHz electromagnetic field effects on melatonin release from isolated pineal glands. med./bio.

Published in: J Pineal Res 2006; 40 (1): 86-91

Aim of study (acc. to author)

To study the direct effects of high-frequency 1800 MHz electromagnetic fields of different SAR levels on melatonin release by isolated pineal organs from Djungarian hamsters.

Background/further details

Both continuous wave and pulsed wave signals were used. The pulse signals were modulated according to the GSM.
The pineal glands were perifused with a special buffer containing the beta-adrenergic agonist isoproterenol to stimulate melatonin synthesis.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1,800 MHz
Modulation type: CW
Exposure duration: continuous for 7 h
  • SAR: 8 mW/kg
  • SAR: 80 mW/kg
  • SAR: 800 mW/kg
  • SAR: 2,700 mW/kg
Exposure 2: 1,800 MHz
Modulation type: pulsed
Exposure duration: continuous for 7 h
  • SAR: 8 mW/kg
  • SAR: 80 mW/kg
  • SAR: 800 mW/kg
  • SAR: 2,700 mW/kg

Exposure 1

Main characteristics
Frequency 1,800 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 7 h
Modulation
Modulation type CW
Exposure setup
Exposure source
Chamber A modified radial waveguide exposure system was used whose principal features have been described in the reference article. Two identical waveguides (diameter 40 cm, height 3 cm) were placed in an incubator at 35 ± 1°C and activated one day prior to each experiment to allow for temperature equilibrium. Every experiment used one unit for exposure and one for sham-exposure controlled (blind randomized) by the data acquisition system.
Setup Inside the radial waveguides, which were terminated by thin absorber sheets (< -20 dB at 2 GHz), 20 glass cylinders each containing a pineal gland were arranged at a constant distance from a cone antenna in the center. The flexible tubes of the pumping system were connected to the glass receptacles through circular waveguides beyond cut-off to prevent any RF leakage. Each exposure unit contained one calibrated temperature probe instead of a pineal gland within a glass cylinder.
Additional info Different intensities for SAR values of 8, 80, 800, and 2700 mW/kg were used according to detailed calculations of the absorbed RF-EMF in the pineal gland tissue. The upper limit of 2700 mW/kg SAR was selected because pre-experiments revealed that higher values caused thermal effects (i.e. temperature differences of more than 1°C between exposed and control units).
Parameters
Measurand Value Type Method Mass Remarks
SAR 8 mW/kg - calculated - -
SAR 80 mW/kg - calculated - -
SAR 800 mW/kg - calculated - -
SAR 2,700 mW/kg - calculated - -

Exposure 2

Main characteristics
Frequency 1,800 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 7 h
Modulation
Modulation type pulsed
Additional info

GSM-modulated

Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 8 mW/kg - calculated - -
SAR 80 mW/kg - calculated - -
SAR 800 mW/kg - calculated - -
SAR 2,700 mW/kg - calculated - -

Reference articles

Methods Endpoint/measurement parameters/methodology

Investigated organ system:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

Both types of signal significantly enhanced melatonin release at 800 mW/kg, while at 2700 mW/kg melatonin levels were elevated in the continuous wave, but suppressed in the GSM-exposed pineal glands. As a temperature rise of approximately 1.2°C was measured at 2700 mW/kg, effects at this level are thermal.

Study character:

Study funded by

Related articles