Study type: Medical/biological study (experimental study)

Effects of combined DC and AC magnetic fields on germination of hornwort seeds med./bio.

By: Kobayashi M, Soda N, Miyo T, Ueda Y
Published in: Bioelectromagnetics 2004; 25 (7): 552-559
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Aim of study (acc. to author)

To investigate the effects of combined exposure to extremely low frequency magnetic fields (ELF AC fields) and local geomagnetic field (DC field) on germination of hornwort seeds (Cryptotaenia japonica).

Background/further details

Three directions of the applied ELF magnetic AC field were considered (i.e. the vertical, the parallel, and the perpendicular) in relation to the geomagnetic DC field.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 3.5–14 Hz
Exposure duration: repeated daily exposure, 24 h/day for 16 days
Exposure 2: 7 Hz
Exposure duration: repeated daily exposure, 24 h/day for 16 days
Exposure 3: 7 Hz
Exposure duration: repeated daily exposure, 24 h/day for 16 days

Exposure 1

Main characteristics
Frequency 3.5–14 Hz
Type
Waveform
Exposure duration repeated daily exposure, 24 h/day for 16 days
Exposure setup
Exposure source
Setup petri dish placed in the center of a pair of Helmholtz coils
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 50 µT - measured - Geomagmetic field
magnetic flux density 750 µT effective value measured - vertical field
magnetic flux density 500 µT effective value measured - vertical field

Exposure 2

Main characteristics
Frequency 7 Hz
Type
Waveform
Exposure duration repeated daily exposure, 24 h/day for 16 days
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 50 µT - measured - Geomagmetic field
magnetic flux density 750 µT effective value measured - AC field orthogonal to the geomagnetic field
magnetic flux density 500 µT effective value measured - AC field orthogonal to the geomagnetic field

Exposure 3

Main characteristics
Frequency 7 Hz
Type
Waveform
Exposure duration repeated daily exposure, 24 h/day for 16 days
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 50 µT - measured - Geomagmetic field
magnetic flux density 500 µT effective value measured - AC field parallel to the geomagnetic field
magnetic flux density 750 µT effective value measured - AC field parallel to the geomagnetic field

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

The geomagnetic field in addition with a vertical AC field at 750 µT at 7 Hz or 500 µT at 14 Hz effectively promoted the germination of the seeds. The parallel AC field was more effective than the perpendicular field.

Study character:

Study funded by

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