Medical/biological study (experimental study)

Resting EEG effects during exposure to a pulsed ELF magnetic field med./bio.

By: Cook CM, Thomas AW, Keenliside L, Prato FS

Published in: Bioelectromagnetics 2005; 26 (5): 367-376

Aim of study (acc. to author)

To study the effects of pulsed extremely low frequency magnetic fields on the human EEG during the exposure period.

Background/further details

In a previous study it was shown that after a 15 min exposure to a pulsed extremely low frequency magnetic field, with most power at frequencies between 0 and 500 Hz, human brain electrical activity is affected, specifically within the alpha waves frequency (8-13 Hz) (see publication 10628).

Endpoint

effects on the neurological system: EEG

Exposure

- magnetic field
- low frequency
- signals/pulses

Exposure	Parameters
Exposure 1: unspecified Modulation type: pulsed Exposure duration: 15 min	magnetic flux density: 200 µT peak value

Exposure 1

Main characteristics

Frequency	unspecified
Type	magnetic field
Waveform	pulsed
Exposure duration	15 min

Modulation

Modulation type	pulsed
Additional info	853 ms segment consisting of 18 pulses with each pulse having a maximum rise of 1 ms. Each pattern consised of a pulse segment followed by varying refractory periods of 110, 220, 330 ms plus a constant fourth period of 5000 ms after which another pulse segment (853 ms) was delivered. This pattern was repeated for 15 min.

Exposure setup

Exposure source	Helmholtz coils
Setup	Subjects were seated in the exposure system consisting of three orthogonal square coils with only the vertical coil pair powered.
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	200 µT	peak value	unspecified	-	-

Reference articles

Cook CM et al. (2004): Resting EEG is affected by exposure to a pulsed ELF magnetic field

Exposed system:

human
whole body

Methods Endpoint/measurement parameters/methodology

effects on the neurological system: resting EEG
EOG

Investigated system:

investigation on living organism

Investigated organ system:

brain/CNS

Time of investigation:

before exposure
during exposure
after exposure

Main outcome of study (acc. to author)

Occipital alpha waves activity (8-13 Hz) decreased during exposure to a pulsed extremely low frequency magnetic field compared to sham exposure. This effect was revealed after the first 5 min of a 15 min irradiation and was dependent on the magnetic field/sham order of exposure. This decrease was no longer significant in the first minute post-exposure, compared to sham exposure.
(Discrepancies between the current results and the data of the previous study suggest that the EEG changes may be sensitive to the characteristics of the magnetic field pulse train).

Study character:

medical/biological study
experimental study
full/main study

Study funded by

Canadian Foundation for Innovation (CFI), Canada
Canadian Institutes of Health Research (CIHR)
Ontario Innovation Trust (OIT), Canada
Ontario Research and Development Challenge Fund (ORDCF), Canada
Plunkett Foundation, UK

Replication studies

Cook CM et al. (2009): Changes in human EEG alpha activity following exposure to two different pulsed magnetic field sequences

Modolo J et al. (2017): Human exposure to power frequency magnetic fields up to 7.6 mT: An integrated EEG/fMRI study
Legros A et al. (2012): Neurophysiological and behavioral effects of a 60 Hz, 1,800 µT magnetic field in humans
Cvetkovic D et al. (2009): Alterations of human electroencephalographic activity caused by multiple extremely low frequency magnetic field exposures
Cook CM et al. (2009): Changes in human EEG alpha activity following exposure to two different pulsed magnetic field sequences
Perentos N et al. (2008): The effect of GSM-like ELF radiation on the alpha band of the human resting EEG
Carrubba S et al. (2007): Nonlinear EEG activation evoked by low-strength low-frequency magnetic fields
Carrubba S et al. (2007): Evidence of a nonlinear human magnetic sense
Cvetkovic D et al. (2006): Alterations in Human EEG Activity Caused by Extremely Low Frequency Electromagnetic Fields
Cook CM et al. (2004): Resting EEG is affected by exposure to a pulsed ELF magnetic field