Electromagnetic fields: what they are and where they are generated in your home

Every time you turn on your router, heat up food in the microwave, or leave your phone charging on the bedside table, your home generates an electromagnetic field. It is not an exceptional phenomenon, nor is it exclusive to telecommunications antennas; it is a physical consequence of any electrical current and any device that emits radio waves.

Understanding exactly what an electromagnetic field is and at which specific points in the house it is generated is the first step to making informed decisions about your daily exposure, without falling into alarmism or misinformation.

What is an electromagnetic field?

An electromagnetic field is the region of space in which two physical forces combine: an electric field, produced by the presence of a charge or voltage, and a magnetic field, produced by the movement of that charge through a conductor. Both components always travel together and are generated as soon as an electric current flows, whether through a cable in the wall or the internal antenna of a router.

Electromagnetic fields are not a recent technological invention. They exist naturally on the planet—the Earth's magnetic field, lightning strikes—and have always accompanied living beings. What has changed in recent decades is their origin: today, most of the electromagnetic fields to which we are exposed at home are of artificial origin, generated by electrical installations and connected devices that operate simultaneously and constantly.

Types of electromagnetic fields according to their frequency

Not all electromagnetic fields behave the same way. The frequency—the number of oscillations per second—determines their range, their penetration capacity, and the type of device that generates them.

Extremely Low Frequency (ELF) fields

These are produced by any electrical installation: home wiring, the electrical panel, household appliances, and nearby high-voltage lines. In Spain, they oscillate around 50 Hz, the frequency of domestic alternating current. Their intensity is higher near the cable or device and decreases rapidly as you move away.

Radiofrequency (RF) fields

These are emitted by devices that transmit information wirelessly: WiFi routers, mobile phones, Bluetooth speakers, remote controls, 5G networks, and the microwave itself. They work at much higher frequencies—from megahertz to gigahertz—and travel through the air, passing through walls with varying penetration capacities depending on the material.

Both types are non-ionizing radiation: they do not have enough energy to break molecular bonds, unlike X-rays or nuclear radiation. If you want to delve deeper into how this entire variety of waves—from visible light to radio frequencies—is classified, you can consult our guide on the electromagnetic spectrum.

Where electromagnetic fields are generated in your home

A modern home brings together, in a small space, a number of sources of electromagnetic fields that did not exist just twenty years ago. Reviewing room by room helps to understand where daily exposure really comes from.

Living room and common areas

The WiFi router is, in general, the most constant source of radiofrequency in the entire house: it emits 24 hours a day, whether in use or not. Around it are the connected television, smart speakers that are always listening, and Bluetooth remotes, all of which are continuously exchanging data.

Kitchen

The microwave is one of the appliances that emits the most radiofrequency radiation while it is running, although its use is usually occasional. The induction cooktop, on the other hand, generates quite intense low-frequency electromagnetic fields in the immediate vicinity of the hob while cooking.

Bedroom

This is the room that most concerns those who learn about this topic because it usually concentrates several sources very close to the body for hours: the mobile phone on the nightstand, the WiFi-connected alarm clock, the wireless charger, and, sometimes, a poorly placed router on the other side of the wall that faces the head of the bed.

Electrical installation and meter

The wiring that runs through walls and floors, the electrical panel, and the smart meter generate low-frequency fields constantly, even if they are not perceived. Added to this is what is known as "dirty electricity": high-frequency harmonics introduced into the grid by switching power supplies, dimmer switches, and certain low-quality chargers.

Why identifying electromagnetic field sources matters

Knowing which device generates which type of field is not a theoretical exercise: it allows for prioritization. A router that spends the night two meters from the bed does not have the same potential impact as one located in the living room, at the other end of the house. Identifying the closest and most constant sources—particularly those in the bedroom, where we spend between six and eight hours in a row—is the starting point for reducing exposure without needing to give up any device.

This identification is especially relevant for people with electrosensitivity, a condition recognized by the WHO in which symptoms manifest more intensely upon exposure to electromagnetic fields. If you want to know the symptoms and how it is diagnosed, we explain it in detail in our article on electrosensitivity. To also understand how this accumulation of sources can translate into specific symptoms—from sleep disturbances to persistent fatigue—you can read our guide on what is electromagnetic pollution and how does it affect us.

How to reduce exposure to electromagnetic fields at home

Reducing exposure does not require disconnecting from technology, but rather reorganizing how you live with it:

• Move emitting devices away from the areas where you spend the most time. The intensity of an electromagnetic field drops with the square of the distance, so a few meters make a real difference.
• Remove the router and mobile phone from the bedroom, or at least from the bedside table, especially during sleeping hours.
• Replace wireless connections with wired ones whenever possible: an Ethernet cable or a wired charger directly eliminates the radiofrequency emission of that device.
• Check your electrical installation if you suspect dirty electricity, especially if you have dimmer switches or many chargers connected at the same time.
• Use electromagnetic filtering technology in areas with the highest density of sources. Unlike shielding, which blocks the signal and may cause devices to emit at higher power to compensate, filters based on SPIRO® technology reorganize the structure of the waves to make them more compatible with the body, without cutting connectivity.

If your main area of concern is the bedroom, in our guide on how to filter a room from electromagnetic waves, we review in detail which methods work, which have real limitations, and what alternatives exist to reduce nighttime exposure without losing coverage.

Frequently asked questions about electromagnetic fields

Are electromagnetic fields in the home dangerous?

Standard levels in a home are, in general, well below the reference limits established by organizations such as ICNIRP. This is non-ionizing radiation, which does not have enough energy to directly damage DNA. That said, prolonged and cumulative exposure to multiple sources remains the subject of research, and organizations like the WHO recommend applying the precautionary principle, especially in the bedroom.

What is the difference between an electric field and a magnetic field?

The electric field is generated by the mere presence of voltage, regardless of whether there is current flowing; this is why a cable plugged into the wall, even if the appliance is turned off, continues to generate an electric field. The magnetic field, on the other hand, only appears when current flows, that is, when the device is actually in operation. Both usually appear together in any active electrical installation.

Does WiFi generate more electromagnetic fields than electrical wiring?

They are of a different nature and cannot be compared directly. WiFi emits radiofrequency constantly but at low individual power; electrical wiring generates low-frequency fields whose intensity depends on the current flowing at any given moment. In practice, both contribute to the total exposure of the home and should be taken into account separately.

How do I know which devices in my house generate the most electromagnetic fields?

The most reliable way is to measure it with an electromagnetic field meter, capable of detecting both radiofrequency and low-frequency fields and dirty electricity. Taking readings next to each device and in the spots where you spend the most time—especially next to the bed—allows you to identify, with real data rather than intuition, which are the priority sources to act upon.