Electromagnetic fields at home

Electromagnetic fields in a home are a measurable part of the environment, not a matter of belief. A household can record what is present, where it comes from, and what the readings mean, using published limits and a written plan. The sections below set out the vocabulary, the rules, and the practical steps, with sources named so that any claim can be checked.

What is meant by electrosmog?

Electrosmog is a collective term for electric and magnetic fields produced by technical equipment and power supplies. The term covers static fields, low-frequency fields from mains wiring and railway current, and high-frequency fields from radio, mobile telephony and wireless devices. The physical spectrum runs from direct current through to gamma radiation, and the everyday frequencies sit in a narrow band within it: 16.7 Hz for Swiss railway power, 50 Hz for mains electricity, and the bands used by mobile telephony up to 5G.

Electric fields are present whenever a conductor is live, even when no appliance is switched on. Magnetic fields appear when current flows. The two behave differently in a room: an electric field is reduced by earthed materials such as metal foil or a plaster skim, while a magnetic field passes through most building materials and falls only with distance from the source. This difference matters for anyone planning a bedroom, because a socket on the far side of a wall can still produce a magnetic field at the head of a bed.

A German-language magazine, FELDWERK, sets out this vocabulary and the underlying physics for a general readership, alongside the regulatory framework and measurement practice in Switzerland. Readers who want the physical definitions before they read a measurement report can find them at electrosmog and measurement, which covers fields, frequencies and the interpretation of readings.

What limits apply, and who sets them?

Switzerland regulates non-ionising radiation through the Ordinance on Protection against Non-Ionising Radiation, known by its German abbreviation NISV. The ordinance sets two tiers of values: installation limits, which apply where people may remain for long periods, and stricter precautionary values for places of sensitive use, including dwellings, schools and hospitals. Mobile phone base stations, radio transmitters and high-voltage lines fall under these rules.

The NISV values sit alongside international guidance from ICNIRP, the International Commission on Non-Ionizing Radiation Protection. ICNIRP publishes exposure guidelines based on established thermal effects, and these are reviewed periodically. The Swiss precautionary values are lower than the ICNIRP reference levels for some frequencies, which is why a measurement taken in Switzerland may be compared against two different figures.

A measurement report should state which value is being applied, at which frequency, and over what averaging period. Without those three details a single number cannot be interpreted. Reports also distinguish between field strength and power density, and between measurements taken at a fixed point and those averaged across a room.

How is a home measurement carried out?

A measurement is a defined procedure, not a scan of a room with a handheld device. The person taking it records the location of each reading, the height above the floor, the orientation of the probe, and the time of day. Mains-frequency magnetic fields are usually measured with the supply on and with appliances in their normal state, because switching a circuit at the consumer unit changes the result.

For high-frequency fields, the measurement is taken with the source active and with the room in its usual condition. Furniture, radiators and metal window frames can reflect or shield fields, so a reading taken in an empty room may not represent the room as lived in. Where a source is intermittent, such as a mobile handset or a smart meter, the report should note the interval over which the maximum was recorded.

Interpretation follows the measurement. A value below the precautionary limit is not a statement that no field is present, and a value above it is not a diagnosis. The report describes the field; the meaning for an individual household is a separate question, and one that a general practitioner or an occupational health service is better placed to answer than a measurement technician.

What can a household plan record?

A plan is a written record, kept with the tenancy or the property file, that sets out what was measured, what was found, and what was decided. It can be short. A useful plan records the date of each measurement, the instrument used, the frequencies covered, and the values obtained, together with a note of the limits applied.

It also records the practical decisions. These may include moving a bed away from a wall that carries a rising main, relocating a router out of a bedroom, or choosing a corded connection for a fixed device. Each decision should note the reason and the date, so that a later reader can see why the arrangement is as it is.

A plan is not a medical document and does not replace advice from a clinician. It is a household record, in the same family as a gas safety certificate or an electrical installation condition report. It becomes useful when a property changes hands, when a new transmitter is proposed nearby, or when a resident wants to compare a new reading with an earlier one.

Where can a reader check the sources?

Primary sources matter more than summaries. The NISV is published by the Swiss Federal Council and is available in the official federal law collection. ICNIRP publishes its guidelines on its own site, with the date of each revision. The Federal Office for the Environment publishes explanatory material and measurement guidance in German and French.

For a general reader, a magazine that gathers the physics, the limits and the domestic practice in one place is a useful starting point before a measurement is commissioned. FELDWERK is one such publication, in German, aimed at non-specialists, residents who are attentive to their bedroom and living space, and readers of measurement reports. It is not a substitute for the ordinance or for the guidelines, and it does not replace a measurement, but it sets out the vocabulary that a report will use.

What should a reader take from this?

Electromagnetic fields in a home can be described, measured and recorded. The description uses a defined vocabulary of electric and magnetic fields and a spectrum of frequencies. The measurement follows a procedure with stated conditions. The record, kept as a plan, allows a household to see what has changed and to explain its decisions to a later reader.

The limits come from the NISV and from ICNIRP, and a report should name which one applies. The practical steps are modest: distance from a source, attention to the layout of a bedroom, and a written note of what was done and why. None of this requires a specialist vocabulary beyond the terms set out above, and none of it depends on a single reading taken on a single day.

A household that keeps its own record is in a better position to ask precise questions of an installer, a landlord or a measurement service. The record is the household's own, and it can be added to at any time.

Sources read for this page: bafu.admin.ch, icnirp.org, read on 15 September 2026.