Study type: Medical/biological study (experimental study)

Effects of microwave and radio frequency electromagnetic fields on lichens med./bio.

By: Urech M, Eicher B, Siegenthaler J
Published in: Bioelectromagnetics 1996; 17 (4): 327-334
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Aim of study (acc. to author)

To investigate the effects of electromagnetic fields on the growth rates of two different species of lichens.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.45 GHz
Modulation type: CW
Exposure duration: 24 h/day up to 800 days
Exposure 2: 2.45 GHz
Modulation type: CW
Exposure duration: 14 h
Exposure 3: 9.5 MHz
Modulation type: CW
Exposure duration: 15 h/day up to 300 days

General information

the experiment was done with a) dry lichen b) wet lichen

Exposure 1

Main characteristics
Frequency 2.45 GHz
Type
Exposure duration 24 h/day up to 800 days
Modulation
Modulation type CW
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power density 50 mW/cm² maximum calculated - -
power density 5 mW/cm² - calculated - -
power density 0.2 mW/cm² minimum calculated - -
power 600 W - measured - -

Exposure 2

Main characteristics
Frequency 2.45 GHz
Type
Exposure duration 14 h
Modulation
Modulation type CW
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power density 50 mW/cm² - calculated - -

Exposure 3

Main characteristics
Frequency 9.5 MHz
Type
Exposure duration 15 h/day up to 300 days
Modulation
Modulation type CW
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 235 V/m maximum measured - -
magnetic field strength 332 mA/m maximum measured - -
power 250 kW - calculated - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

A significantly reduced growth rate of both lichens species was observed when exposed with a power density of 50 mW/cm2. At a power density of 5 mW/cm2 or below, no alteration was observed. A differntation between thermal and nonthermal effects was not feasible, but a thermal mechanism is suspected.
Exposure at 9.5 MHz leads to no observable alterations at all.

Study character:

Study funded by