Electricity... step by stepWhat are the basic concepts to keep in mind when considering the effects of electricity on health? To start, click (in the picture below) on the word you want to reach, or here to follow our predefined course.
Should we worry about the electric field, magnetic field or contact currents? The magnetic field crosses through the human body almost without change between the outside and the inside of the body, whereas the electric field only partly penetrates it (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 the human body should not be neglected. Indeed, what is really important for health is the electric field inside the human body (see ICNIRP guidelines, 1998, 2010). It could disturb some biological processes. However, this is valid only if the electric field reaches a minimal threshold. It is estimated at around 100mV/m (see ICNIRP guidelines, 1998, 2010). It does not mean that this threshold is pathogenic, but simply that cell behavioral changes could be induced at this threshold or above (temporary or not) that could lead or not to a (positive or negative) health effect. To reach this 100 mV/m threshold in our body, the external source can be an electric field (higher than more or less 10 kV/m), a magnetic field (higher than more or less 100 µT) or a contact current (higher than more or less 100 mA). A current is generated inside the body by all these external sources, a current that will run through the body according to the electrical conductivity of local areas. As each current is linked to an electric field by the Ohm's law, it means that if one exists the other exists too. Thus there is no valid scientific reason to essentially worry about the magnetic field.
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