Measurement Values and Guidelines
What do the numbers on the map mean?
μW/m²
On this website all values are expressed in Microwatt per square metre (μW/m²). This is a fine-grained scale used to express radiation intensity. Some organisations work with values in Watt per m², Volt per metre, dBm or dBW. You can convert these values using the EMF calculator.
EMF Calculator
Convert EMF values between different units:
Info: The conversion between V/m and power density (W/m²) is based on the formula: P = E² / 377, where 377 Ω is the impedance of free space. dBm and dBW are logarithmic units: dBm = 10 × log₁₀(W/m² × 1000), dBW = 10 × log₁₀(W/m²).
Measurement Value Legend
On EMF Map NL, measurement values are recorded in microwatt per square metre (μW/m²). A classification for the measurement values is used, derived from the guidelines of the SBM, the BioInitiative and the Council of Europe. Up to 100 μW/m² is green, little radiation. Above that follows orange, red, dark red and black. The colour is based on the measured maximum peak value.
Microwatt per square metre (μW/m²) is a fine-grained scale used to express radiation intensity.
ICNIRP 2020
The limits set by the Government are based on guidelines from the ICNIRP from 2020. They recommend a maximum of 10 Watt/m² or 10.000.000 μW/m² for outdoor spaces. For some frequencies a slightly lower level applies.
Physics versus Biology
The ICNIRP states that damage can only occur through heating. They exclude biological effects. To determine limits for that heating, they test as follows: for six minutes, a head filled with salt water is exposed to radiation. After exposure, the difference in temperature is measured. The heating must remain below 1 degree Celsius.
But is a human being a bag of salt water? Or is a human being a biological entity within which all kinds of electromagnetic processes take place? Biological studies lead to different outcomes. The influence of EMF on processes in the body shows harmful effects, even at very low radiation levels.
SBM 2024
The joint Building Biologists from Germany, after thousands of practical studies, have developed their own guideline, the SBM from 2024. In it they recommend a maximum exposure of 0,1 μW/m² for bedrooms. The SBM does not make a statement about radiation levels in outdoor spaces.
BioInitiative 2012
The largest review study "The BioInitiative" arrives at a considerably lower guideline. After studying more than 1,600 scientific studies, they see 30 μW/m² as a justified threshold. To ensure radiation is safe for prolonged exposure and for children, they propose as a guideline 3,0 μW/m² to 6,0 μW/m² for outdoor spaces.
Council of Europe 2011
In 2011, the Council of Europe issued an opinion stating that the guidelines of the ICNIRP were outdated. Based on the precautionary principle, the Council considered it necessary to substantially lower the limits. They arrived at a maximum of 0.2 V/m, or 100 μW/m² for indoor spaces.
Averages versus Peak Values
Biologists find that peak values are harmful, while the ICNIRP looks only at average values. The international convention is to divide radiation peaks by the time between these peaks. In practice, this leaves only about 10% as average radiation.
It is a bit like a boxing match. It is not the average, it is the punch (the peak value) that causes the knockout.
Health Complaints
Biological effects from exposure to EMF radiation have been demonstrated in countless studies. The first effects include insomnia, concentration problems, headache, neck and shoulder pain. EMF is classified by the W.H.O. as a possible carcinogen. On sites such as PubMed and EMF Portal, thousands of studies can be viewed. A selection of the studies is included in the table below, with studies ranked by radiation intensity category (green to black).
