Electric fields, magnetic fields or contact currents?

Magnetic fields go through the human body practically unchanged from outside to inside, whereas electric fields only partially penetrate the body (it is roughly reduced by a one million factor between the outside and the inside of the body; it mainly causes the migration of electric charges (ions) towards the surface of the body).

However some researchers consider that the effects of electric fields on living organisms should not be neglected. Indeed, what counts as far as health is concerned is the internal electric field inside the human body (see the ICNIRP guidelines, 1998, 2010). It alone could disturb some of the physiological processes. This implies however that it does reach a minimum threshold beyond which our organism is affected. This threshold has been evaluated and is about 100 mV/m (see the ICNIRP guidelines, 1998, 2010). This doesn’t mean that it is pathogenic, but simply that beyond this threshold, some cell behaviour may be modified (temporarily or not), possibly leading to (positive or negative) effects in our well being.

To reach this 100 mV/m threshold inside our body, the external source may be an electric field greater than 10 kV/m, a magnetic field greater than 100 µT or a contact current of more than 100 µA.

All these external sources generate a current through the body, current that will follow a path determined by the local electrical conductivity encountered. As any current is related to an electric field by Ohm’s law, if one exists, the other exists also.

Therefore, there is no scientific reason to be particularly concerned with the magnetic field.

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