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Exposure to fields in everyday life

  • Several years ago, the BfS carried out a study on the “Assessment of the Bavarian citizens’ exposure to low frequency magnetic fields” on behalf of the Bavarian State Ministry for Regional Development and Environmental Affairs.
  • From 24-hour measurements obtained using personal dosimeters worn on the body, an arithmetic mean of 0.101 µT and a median value of 0.047 µT were determined for the magnetic field at 50 hertz.
  • Current data on the exposure of the general population is being collected within the framework of the research programme “Radiation Protection in the Process of Power Grid Expansion”.

A study on the "Assessment of the Bavarian citizens' exposure to low frequency magnetic fields" conducted by BfS on behalf of the Bavarian State Ministry for Regional Development and Environmental Affairs (Bayerisches Staatsministerium für Landesentwicklung und Umweltfragen) some years ago suggests an arithmetic mean value of 0.101 microtesla and a median value of 0.047 microtesla for all individuals under study, based on 24h-measurements carried out using body worn dosimeters.

Within the scope of the research programme on "Radiation Protection in the Process of Power Grid Expansion" current data on the exposure of the general public are collected.

Magnetic field exposure for the general population (representative of the settlement structure in Bavaria) due to the 50 Hertz power supply
PeopleMean value in microtesla Median in microtesla 95 percent percentile in microtesla
24 hour exposure1.9520,1010,0470,308
exposure in the house1.9410,0900,0630,215
exposure at night1.9260,0950,0920,144
large city, 24 hours3700,1150,0610,314
rural, 24 hours4320,0770,0350,261
one family house 1.2270,0920,0590,218
high-rise building510,0970,0760,116
Apartment near high voltage power lines4170,1120,0610,299
24-hour data: office workers6240,1070,0490,338
24-hour-data: craftsmen / workers1480,1660,0490,628
24-hour-data: not employed9220,0930,0460,258

Source: Federal Office for Radiation Protection (BfS)

For people who stated that they used an electric radio alarm clock, the night-time exposure was on average about two and half times greater than that of the rest of the participants. Whereas the night-time exposure of people who said they did not use an electric radio alarm clock was 0.058 or 0.054 microtesla (mean or median value), it was 0.149 or 0.146 microtesla (not listed in the above table) for people who said they did use an alarm clock of this kind.

Subjects who said they lived in a building that had a mains infeed via the roof or that was in the vicinity (within 100 metres) of a high-voltage power line experienced only slightly higher values than the participants as a whole. Accordingly, the mean exposure in this group was 0.112 microtesla (as opposed to 0.101 microtesla for the participants as a whole) and the median value was 0.061 microtesla (as opposed to 0.047 microtesla for the participants as a whole).

This was the first study that also determined the level of exposure to magnetic fields from traction current installations. For 190 people who stated that they lived close to a railway line, the mean exposure was 0.16 microtesla at 16.7 Hz; the median was 0.1 microtesla.

Exposure of craftsmen to fields

Here, there are clearly discernible differences between day and night and between working time and time spent at home.

In work involving powerful electrical equipment (such as welding equipment or drills), the exposure to low-frequency magnetic fields reached relatively high levels – up to 45 microtesla at around 1 p.m.

Housewife

The level of exposure to low-frequency magnetic fields (magnetic flux density) differs between day and night.


When time is spent in the vicinity of powerful electrical appliances (e.g. washing machine, cooker, vacuum cleaner), the exposure reaches peak values of between 0.4 and 2 microtesla (µT).

Radio alarm clock

In many cases, higher exposure to low-frequency magnetic fields was observed at night than during the day.

This was generally down to the fact that the radio alarm clock was positioned less than 30 centimetres from the bed.

Measurements of magnetic flux density at greater distances from radio alarm clocks yielded significantly lower values.

State of 2023.11.14

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