Study type: Medical/biological study (experimental study)

Effects of A 60 Hz Magnetic Field of Up to 50 milliTesla on Human Tremor and EEG: A Pilot Study med./bio.

Published in: Int J Environ Res Public Health 2017; 14 (12): E1446

Aim of study (acc. to author)

To evaluate whether a 60 Hz magnetic field could induce acute modulations in postural tremor or EEG of human subjects.

Background/further details

Ten healthy subjects (mean age of 23.8 years), 5 males and five females, were included in the study.
Subjects equipped with the EEG cap were seated in an armchair and provided with earplugs. Then, they were exposed to eleven conditions (sham exposure, 5 mT, 10 mT, 15 mT, 20 mT, 25 mT, 30 mT, 35 mT, 40 mT, 45 mT and 50 mT), respectively presented for 5 seconds. Each of the eleven exposure conditions was repeated for five times with the order being randomized. During exposure, subjects were asked to to keep their pointing finger position as stable as possible.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 60 Hz
Exposure duration: 5 seconds per exposure condition

Exposure 1

Main characteristics
Frequency 60 Hz
Type
Waveform
  • unspecified
Exposure duration 5 seconds per exposure condition
Exposure setup
Exposure source
Setup head exposure system consisted of a 176-turn coil (16 layers of 11 turns each, 6 cm inner diameter and 22 cm outer diameter) made of hollow square copper wire cooled by circulating water; coil could generate the magnetic field without any perceptible noise or vibration
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 50 mT maximum measured and calculated - 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50 mT

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

No significant modulations in postural tremor characteristics were found. However in EEG, a significant main effect for magnetic field exposure was found for electrodes covering the left primary somatosensory cortex (CP3 and CP5) suggesting a decreased µ waves power spectral density with increasing magnetic flux density. However, further analysis (Bonferroni correction) did not confirm the effects.
The authors conclude that this human pilot study did not show physiological tremor modifications but suggested a possible effect of 60 Hz magnetic fields in the high mT-range on the brain region related to tactile perception and further research is needed.

Study character:

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