Study type: Medical/biological study (experimental study)

Effects of weak pulsed magnetic fields on chick embryogenesis. med./bio.

Published in: Selected Papers from the International Scientific Conference on Works with Display Units: Stockholm, Schweden, May 12-15, 1986 Elsevier, 1987, ISBN 9780444701718: 135-140

Aim of study (acc. to author)

To study whether magnetic fields with a asymmetrical sawtooth waveform could influence the early development of chick embryos.

Background/further details

285 fertilized eggs were divided into the exposure group (n=149) and control group (n=136). Exposure eggs were exposed to three different magnetic flux densities (0.1, 1.5 and 16 µT) during the first two days of development.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 20 kHz
Modulation type: pulsed
Exposure duration: continuous for 42 h
Exposure 2: 20 kHz
Modulation type: pulsed
Exposure duration: continuous for 42 h
Exposure 3: 20 kHz
Modulation type: pulsed
Exposure duration: continuous for 47 h

Exposure 1

Main characteristics
Frequency 20 kHz
Type
Waveform
  • sawtooth-shaped
Exposure duration continuous for 42 h
Modulation
Modulation type pulsed
Rise time 45 µs
Fall time 5 µs
Additional info

simulation of a visual display terminal

Exposure setup
Exposure source
Setup eight coils with a diameter of 6 cm, 8.3 cm long, made of 98 turns of 0.7 mm enamelled copper wire; coils connected in parallel; exposure system placed inside an incubator at a constant temperature of 38°C ± 0.2°C; each egg placed horizontally inside one coil; electric equipment placed half a meter from the incubator chamber and the fan was covered with magnetic shielding alloy to limit the 50 Hz background fields
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.1 µT - - - -
cf. remarks - - - - dB/dt = 0.03 T/s

Exposure 2

Main characteristics
Frequency 20 kHz
Type
Waveform
  • sawtooth-shaped
Exposure duration continuous for 42 h
Modulation
Modulation type pulsed
Rise time 45 µs
Fall time 5 µs
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.5 µT - - - -
cf. remarks - - - - dB/dt = 0.3 T/s

Exposure 3

Main characteristics
Frequency 20 kHz
Type
Waveform
  • sawtooth-shaped
Exposure duration continuous for 47 h
Modulation
Modulation type pulsed
Rise time 45 µs
Fall time 5 µs
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 16 µT - - - -
cf. remarks - - - - dB/dt = 3.3 T/s

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

No statistically significant differences between exposed and control embryos were observed with respect to developmental stage and malformations.

Study character:

Study funded by

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