Magnetic alternating springs are created where current flows. Whenever a consumer, for example a lamp or a machine, runs and consumes electricity, an alternating magnetic field is created. The alternating current flowing in cables and transformers can also be cited as a cause if devices are on. Alternating magnetic fields flow through human bodies unhindered. Alternating magnetic fields can also be caused by poor electrical installations in the house and defective devices. In low-voltage systems and all devices that are operated with a transformer, the alternating electrical fields can also be large.
Other causes of alternating magnetic fields in the house include kitchen appliances, portable cassette recorders, plug-in power supplies, battery chargers, baby monitors, dimmers, antenna amplifiers, fluorescent tubes, energy-saving lamps, electric underfloor heating and all kinds of motors.
However, alternating magnetic fields can also enter the house as stray currents (e.g. from trams, power lines or transformer houses) from outside via pipes and can sometimes be very strong.
High-voltage lines, with voltages of 110 kilovolts, 220 kV or 380 kV with currents well over 800 amperes, are among the strongest causes of electrosmog.
Railways and trams are also a major cause of magnetic fields. Mains or traction current can penetrate into residential areas over quite long distances via, for example, conductive pipes in the street (gas, water, district heating) or the ground. Since these stray currents flow uncompensated, they sometimes cause very strong fields. According to Wolfgang Maaes, the average exposure to alternating magnetic fields in residential areas is 20-50 nanotesla (Nt), in large cities it is 50 to 60 nT and in rural areas it is 20 to 30 nT.
The flux density of alternating magnetic fields is given in Tesla (T); in building biology the unit of measurement is nanotesla (nT). The flux density is also called induction. The field strength is ampere per meter (A/m), the frequency is hertz (Hz) or kilohertz.
What can you do yourself?
Please keep your distance from the previously mentioned field polluters. If you have one, switch off your electric underfloor heating at night using the fuse box. Avoid lamps with dimmers right next to the bed, the same goes for clock radios and power adapters.
What we can do for you?
We can check your bedroom, your apartment, your company and your office with the necessary measuring devices for noticeable anomalies in the area of the alternating magnetic fields and thus make you aware of the fields. It's often enough to keep your distance from certain things if you know them. Since alternating magnetic fields can also come from neighbors or outside, a building biology study makes sense. 24-hour measurements can be useful and necessary near trams, subways or trolleybuses. Alternating magnetic fields are difficult to shield, but there are materials such as MU metals, transformer sheets and special magnetic field-reducing films that can make a difference in many cases.
Possible health effects
In the specialist literature we find symptoms and illnesses that can be associated with alternating magnetic fields: tension, headache, nausea, sleep disorders, visual impairments, depression, cardiac and circulatory disorders, memory loss, respiratory irritation, asthma, dizziness, circulatory problems, irritability, hyperactivity, Migraines, hormonal disorders, immune deficiency, allergies, changes in pulse rate. Cancer and Alzheimer's are mentioned as extremes. The WHO and other scientists speak of a threefold increased risk of leukemia for children and adults at levels of 200-300 nanotesla.
The University of Toronto with its scientific director Prof. L.M. Green: Children who were exposed to magnetic field intensities of over 130 nanotesla in their children's rooms in the first two years of their lives showed a 13.5-fold increased risk of leukemia.
