Study type: Medical/biological study (experimental study)

Repeated exposure to low-level extremely low frequency-modulated microwaves affects cortex-hypothalamus interplay in freely moving rats: EEG study. med./bio.

Published in: Int J Radiat Biol 2010; 86 (5): 376-383

Aim of study (acc. to author)

To compare the effects of repeated exposure to extremely low frequency-modulated microwaves on cortical and hypothalamic electroencephalograms (EEGs) of freely moving rats.

Background/further details

The EEGs were recorded for five consecutive days either under sham exposures (five rats) or under mixed sham exposure/microwave exposures (five rats).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 915 MHz
Modulation type: FM, pulsed
Exposure duration: intermittently: 1 min on - 1 min off - for 10 min, 3 times per day for 3 days during a 5 day period (see "additional information")

Exposure 1

Main characteristics
Frequency 915 MHz
Type
Polarization
Exposure duration intermittently: 1 min on - 1 min off - for 10 min, 3 times per day for 3 days during a 5 day period (see "additional information")
Modulation
Modulation type FM, pulsed
Modulation frequency 4 Hz
Pulse width 20 ms
Exposure setup
Exposure source
  • circular wire antenna with a diameter of 18 cm
Distance between exposed object and exposure source 25 cm
Setup 15 cm x 17 cm x 30 cm Plexiglas box placed in an anechoic chamber lined with pyramidal Eccosorb; antenna fixed in the horizontal plane outside and above the box
Sham exposure A sham exposure was conducted.
Additional info 10 min pre- and post-exposure periods exposure group: sham exposure on day 1 and day 4, MW exposure on days 2, 3 and 5 sham group: sham exposure on all five days remark of the EMF-Portal editor: exposure time was differently described in the method section, the figures and the results of this article
Parameters
Measurand Value Type Method Mass Remarks
power density 0.3 mW/cm² average over time measured - at a distance of 30 cm from the antenna
SAR 0.7 mW/g - - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Extremely low frequency-modulated microwaves increased beta wave2 activity (17.8-30.5 Hz) in both cortical and hypothalamic EEG. Moreover, a cumulative effect under repeated exposures to extremely low frequency-modulated microwaves was found.
In conclusion, the data are in line with evidence that repeated low-level exposure to extremely low frequency-modulated microwaves affects brain functioning and provide an additional approach when analysing underlying mechanisms.

Study character:

Study funded by

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