Study type: Medical/biological study (experimental study)

Water stress reveals effects of ELF magnetic fields on the growth of seedlings. med./bio.

Published in: Electro Magnetobiol 1998; 17 (1): 17-30

Aim of study (acc. to author)

To study the effects of weak and extremely low frequency magnetic fields on the growth of spruce seedlings Picea abies that were exposed simultaneously to stress conditions.

Background/further details

The drought environmental stress conditions were simulated by watering the seedlings with polyethylene glycol at two different concentrations.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: repeated daily exposure, 12 h/day for 7 days or 12 h/day for 9 days; 2 days in water flasks and 7 days in Petri dishes
Exposure 2: 50 Hz
Exposure duration: repeated daily exposure, 12 h/day for 7 days

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration repeated daily exposure, 12 h/day for 7 days or 12 h/day for 9 days; 2 days in water flasks and 7 days in Petri dishes
Exposure setup
Exposure source
Chamber Experimental boxes maintained at about 21.5°C and the experiments were performed in the dark.
Setup Petri dishes were placed at the center between the coils and exposed under normal conditions or under PEG stress (drought environment conditions) which was simulated by watering the seedlings with polyethylene glycol (PEG) at 88 g/L and 176 g/L.
Additional info The axis of the coil was in east west direction in which the geomagnetic field was equal to zero. The coils were placed in a paper box shielded by grounded aluminum foil. The control group was exposed to equal composition and treatment, except that it was not exposed to magnetic field stimulation. The controls were performed by placing the seeds in the non-energized coils as well as placing them in control box which was located at a distance of 3.5 m from the coils. One control was preformed with PEG 88 g/L and the other two under normal conditions. In one experiment (PEG 176 g/L) subgroups were introduced, one group was exposed for 4 days and then placed into the control box for the remaining 3 days and the second group was first placed into the control box and then exposed to MF for the last 3 days.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 26 µT unspecified measured - -

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration repeated daily exposure, 12 h/day for 7 days
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 105 µT unspecified measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The data showed that a weak, sinusoidal magnetic field inhibited the germination and the growth of seedlings (under drought stress), whereas under normal conditions (without polyethylene glycol), the effects were either zero or stimulatory. When the seeds were soaked in water, the effects of magnetic fields were reversed (i.e. they were stimulatory). This supports some findings that biological systems under stress may demonstrate higher sensitivity to extremely low frequency electromagnetic fields.
The data show that the inhibition was greater at the higher concentration (176 g/l) of polyethylene glycol (at 105 µT), whereas the growth as well as the fresh weight did not show this dependence of concentration.
The authors suggest physiological windows, because the quality of responsiveness to magnetic fields may depend on the physiological state of organisms.

Study character:

Study funded by

Related articles