Study type: Medical/biological study (experimental study)

Influence of Calcium Cyclotronic Resonance on the Developmental Rates of Xenopus Laevis Tadpoles. med./bio.

Published in: PIERS Proceedings, Beijing, China (2009) The Electromagnetics Academy, 2009: 983-987, ISBN 9781934142080

Aim of study (acc. to author)

To investigate the effects of 50 Hz magnetic fields combined with static magnetic fields on the development of tadpoles.

Background/further details

Former studies have found biological effects of particularly weak AC magnetic fields but with a frequency close to the cyclotron resonance frequency corresponding to the charge-to-mass ratio of a calcium ion and to the applied DC field (for example Zhadin et al. (1999), Lisi et al. (2006), Garardi et al. (2008)).
Two experiments were performed: experiment 1) 50 Hz magnetic field plus static magnetic field of 65 µT (n=68) and a control group without exposure (n=68) and experiment 2) 50 Hz magnetic field without artificial static magnetic field (only geomagnetic field) (n=68) and a control group without exposure (n=68). Both experiments were repeated three times, i.e., in total 408 tadpoles were used per condition.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 0–50 Hz
Exposure duration: not reported, probably during the whole development
Exposure 2: 50 Hz
Exposure duration: not reported, probably during the whole development

Exposure 1

Main characteristics
Frequency 0–50 Hz
Type
Waveform
Exposure duration not reported, probably during the whole development
Exposure setup
Exposure source
Chamber aquarium with 0.26 m height, 0.26 m width and 0.40 m length
Setup solenoid had a length of 1.60 m and a diameter of 0.38 m and was made of 1600 copper wire turns (diameter 0.001 m); static field was obtained by adding a DC component to the AC component of the current generator
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 65 µT - measured - static field
magnetic flux density 100 µT - measured - 50 Hz

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration not reported, probably during the whole development
Exposure setup
Exposure source
Additional info geomagnetic field was 25 µT
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 100 µT - measured - -

Reference articles

  • Severini M et al. (2003): Sublethal effect of a weak intermittent magnetic field on the development of Xenopus laevis (Daudin) tadpoles.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

In the first experiment, no significant differences were found between the exposed tadpoles (static magnetic field of 65 µT plus 50 Hz magnetic field) and the control ones. However, in the second experiment, a significant delay regarding the developmental stage was found in exposed tadpoles (geomagnetic field plus 50 Hz magnetic field) compared to those from the control group.
The authors conclude that the geomagnetic field could play an important role in the development of tadpoles when exposed to a 50 Hz magnetic field and further hypothesize a correlation to increased calcium ion energy levels.

Study character:

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