RF/HF Radiation & Health

There is a lot of concern about health issues possibly caused by RF and HF energy transmitted by technical equipment. This can be either Satellite, Radar, Cellular or WiFi technology. But if we are really concerned other equipment like magnetrons, TVs and powerlines, either inhouse or public, should be included in this discussion as well. Everything that transports an AC voltage is radiating energy after all.

There are many angles to which you can approach this matter. In this document it is tried to explain everything in a comprehensive way in layman language based on common sense.

If there is concern about the influence of radiation on health (in general) let us start to get the facts about what frequencies have effect on the human body. The human body consists partly from water (H2O) which varies based on your age, gender and health condition. But in general this is around 60% for an adult person. (Source: USGS: the water in you). This makes you a kind of a conductor, but not a really good one. Being a conductor this makes you susceptible for conducting electromagnetic energy as well.

Frequency vs Human body sensitivity

Radiation is electromagnetic energy. Electromagnetic energy will automatically exist if an alternating current (=AC) is send through a conductor. Another conductor in the neighbourhood of that electromagnetic ‘field’ can pick up this energy and the reverse will happen resulting in an current starting to flow through that conductor. The resistance of that conductor will produce a voltage between both ends of the conductor picking up that energy. This is the principle of a transformator in every electronic device in house, either being the charger of your smartphone or the TV in your living room. The main reason for this is because the power line in your house is producing 230V AC (Europe) or 120V AC (US/Canada) with 50 Hz (Europe) or 60 Hz (US/Canada) frequency. This frequency is important in radiating energy. For long distances transmission of lots of energy is a low frequency best suited, that is exactly what the Power Utilities have to do and that is the reason why they go for these low frequencies of 50 or 60 Hz, which are 50 or 60 times/second the voltage is changing from positive to negative and v.v. This polarization change in a regular way is important since this is the only way to start radiating energy. This energy can be picked up by other conductors as explained above. This is just pure physics. You cannot mess around with Nature, there are no shortcuts here.

Going back to what is stated above about human bodies being a conductor this leads to the question; what frequencies have the most influence on the human body? Based on a report of the HPS the US Health Organisation that is specializing in radiation health protection this is in the range of 80 to 100 MHz. 80 million to 100 million changes per second. The FM radio in Europe is using the 87,5 – 108 MHz band meaning that the human body is most vulnerable for free air FM radio radiation. Ofcourse lower and higher frequencies than this range is also having influence on the human body but this will be lower and this will be even more for much lower and much higher frequencies. This characteristic will follow a ‘Gauss curve’ (other parts of the world call it a ‘Bell curve’).

Gauss curve

Energy is most concentrated around the centerfrequency and is decreasing in an equal way at both sides (lower and higher frequencies). The Gauss curve is an important figure that is is coming back in many calculations, like the distance to this radiation object (wire, device or antenna). If you are against the antenna the body will absorb the most amount of energy, if you are moving away from the radiating antenna the energy will exponentialy decrease related to the distance. That having said, the discussion is about how dangerous is cellular radiation to the human body. Cellular frequency bands range from 450 MHz (Northern Europe only) to 3.500 MHz (3.5 GHz). Based on what is already known by now (see above) the human body is not really very ‘sensitive’ for these very to ultra high frequencies.

But actually that is not the only important thing to be mentioned here. It is also about how much energy is ‘thrown in the air’ by the high cellular frequencies. That will be discussed below.

Radiation Energy vs vulnerability

Different electronic devices produce different levels of radiation. Radiation is an alternating electromagnetic energy detectable over a certain area. This is also known as EMF, an electromagnetic field. The value to express the amount of energy radiated is in V/m, voltage per meters. Depending on the frequency range the radiation is experience this is devided in non-ionizing and ionizing frequency ranges.

Ionizing radiation is causing radio activity energy to be produced by the object that is induced by the ionizing radiation. That is happening with x-rays and ultraviolet light. It is proven that this form of radiated energy can cause cell disorders, which can cause different forms of cancer.

Non-ionizing radiation is occurring in lower frequency ranges up to 1000 GHz, where Infrared light is starting. The sun is producing light and heat in the form of Infrared (non-visible) light, visible light and Ultraviolet light. This means that above the visible light the hazardous effects of radiated energy is available as ‘background’ radiated energy. Therefore the real matter to understand is how much is the non-ionizing radiation adding to the constant available harmfull background ionizing radiation. And… can we find a relation between this non-ionizing radiation level and any health issues.

Then the literature becomes a little bit fuzzy. An EMF has actually 2 components, an Electric field and a Magnetic field. The electric energy generated is expressed in V/m, the magnetic energy is expressed in milliGauss (mG) or microTesla (uT). 1 mG is 0,1 uT. This document concentrates on the electric energy induced in the human body that can become harmfull. Ofcourse magnetic energy can be harmful but these levels are much higher than the levels of electric energy. Otherwise you would never being scanned by a MRI in the hospital. So focus on the electric energy.

It is said that for the frequency range 300 to 6000 MHz, which covers the cellular frequency bands the safe limits are 3.142 V/m. This document from a Canadian governmental organisation explains this further. The Dutch regulatory board keeps a 28 V/m as a safe limit.

In the Netherlands the ‘Antenna authority unit’ has conducted extra tests because there is a lot of public concern based on the introduction of 5G and the influence at public health. Especially measurements are done in villages and cities where the cell towers can be approached quite close. In the maps at their website the Dutch Antenna authority unit shows all measured cell towers in a dynamic map. When hoovering the mouse over an individual cell tower (zoom out) it shows the electric energy radiated by this specific cell tower. All values are below this 3.142 V/m. The website and map can be found here.

Fieldstrength measurement at a specific cell tower. Hoover the mouse over the location and the measured values are shown of this specific cell tower.

For your convenience this link will help to convert different unit values to or from each other. There is a lot of information on the internet about this subject however each explanation works with different units. Above are the V/m units being used but we also see explanations with W/m2. FYI, V/m is an Electric Field intensity unit whilst W/m2 is a Power Density unit. These are 2 units that actually express the same issue but in another way. Electric Field intensity, i.e. Field Strength is the magnitude of the field expressed in V/m. Power density is the power equivalent measured at a certain area. These to values are closely related to each other as the link to the conversion formulas above show. Usualy Electric Field strengths are used in the below 1 GHz spectrum and the Power Density in the over 1 GHz spectrum.

Several scientific studies, which all can be found on the Internet, show that nowhere Mobile Network Operators exceed the safety levels that are given for Cellular communications. But there is a catch here that needs to be well understood.

All studies start from the cell tower antennas. However if your cellphone is far away from a cell tower than it automatically raises its output power level to maintain the communications channel to the ‘connected’ cell tower. In that case it radiates more power than in ‘normal’ mode. The values set here are 33 dBm at 900 MHz and 30 dBm at 1800 MHz. Another unit again, sigh… When this all is recalculated this is more or less equal to 2W at 900 MHz and 1W at 1800 MHz. Is this harmfull? This can be discussed as well and many documents and website try to tell us it is whilst others indicate it isn’t at all.

Relate all above information to the ever present sun. That produces a background ‘power’ of 1kW/m2. We cannot escape the sun, however we all know that being in full sun exposure for too long is not healthy. But that is because of the ionizing radiation (UV light) produced by the sun.

OK, 5G will require in the end higher frequencies and 6G will go even higher. That is a law of physics, higher bandwidths require higher frequency bands to operate at. But still we don’t come -by far- in the area of UV light frequencies…. (I know a fallacy of giant proportions but it at least indicates that we are far away from ‘cooking’ frequencies in our radio communications and perhaps that is what it all comes down to).

Last but not least, why all the fuzz about the 5G cell towers? Nobody is talking about the DECT handsets and baby monitoring devices. These radiate about 1000x more energy than cell phone over its full 2.4 GHz spectrum. ‘Nough said?