By Dr Paul Kamweru (Guest Writer)
Recently, we have witnessed an increased debate over the safety of Electromagnetic Fields (EMF) or Electromagnetic Radiations (EMR) occasioned by the rolling out of the next-generation network, 5G.
5G is the technology successor of the mobile phone networks that begun with 1G technology in 1979, and that saw successive replacement by 2G, 3G, and 4G.
Unlike its predecessors the 5G technology is promising to meet consumer demands of high speeds for multiple users, higher number of simultaneous connections, spectral efficiency and improved coverage.
If 5G has these advantages, then, one would ask why there are safety concerns. To understand this, one ought to understand how 5G works.
Unlike 4G, it works on three spectrum bands. These are the Low-band spectrum, Mid-band Spectrum and the High-band spectrum.
These bands are better differentiated using the terms data speed, coverage area, penetration and latency. Speed is both the measure of capacity (bandwidth) to transmit a maximum capacity of data and how many units of this data can be processed in a given amount of time.
The higher the better
How a network is distributed helps us to understand coverage better. Network is distributed over land areas called “cells“, each served by one or more fixed-location transceiver base stations.
The base stations provide the cell with the network coverage. Simply put, penetration is the ability to by-pass barriers. Latency is the term used to indicate the time taken in milliseconds (ms) to upload data from your device to reach a target.
It is an important parameter in applications where the response time impacts the outcome e.g. like in self-driving vehicles. Low-band spectrum offers large coverage area (thus few base stations), good wall penetration but suffers low data speeds.
Mid-band spectrum delivers faster speeds and lower latency than low-band. It does, however, fail to penetrate buildings as effectively as low-band spectrum.
It is the High-band spectrum, also known as mmWave that make 5G both attractive (to potential users) and scary (to alarmists) on equal measure. Attractive since it provides the highest performance in terms of speed of up to 10Gbps and has extremely low latency.
It is scary to alarmists because it has low coverage area and building penetration is poor, meaning that for effective high-band network, you’ll need many small cells. These are low-power base stations that cover small geographic areas and can be combined with beamforming to bolster coverage.
Low energy waves
The type of radiation that mobile phone technology uses belongs to the longer wavelength end of the electromagnetic spectrum. These waves are of lower energy, cannot cause ionization and thus referred to as non-ionizing.
This is in contrast to the ionizing radiations that are ‘strong’ enough to cause ionization i.e. remove an electron from an atom or a molecule.
Radiation Protection Board
The ionizing radiation use and limits control is well documented and regulated. In Kenya for example we have the Radiation Protection Act CAP 243 that establishes a radiation protection board that among others ‘keep a register of the owners of irradiating devices, radioactive materials and other sources of ionizing radiation imported into or manufactured in Kenya and of premises licensed to dispose of radioactive waste’.
Such a law in regard to the non-ionizing radiation doesn’t exist in our country.
The Non-ionizing radiation spectrum can be categorized as (i) optical radiations which consists of UV, visible and infrared (IR) radiation, (ii) static electric and magnetic fields, (iii) extremely low frequency (ELF) and low frequency (LF) electromagnetic (EM) fields and (iv) radiofrequency (RF) radiation.
We are exposed on daily basis to these kinds of non-ionizing radiations. We get and utilize visible and UV light from the sun, and artificial sources.
Almost every household has a remote for a TV set, decoder or any other device and these utilizes infrared radiation. Static electric fields exist either naturally or man-made.
A permanently present electric field results due to the potential difference of around 300 kV between the ground and the Earth’s ionosphere. High voltage DC transmission power lines can produce static electric fields of up to 20 kV/m and more.
DC operated electric trains, can generate static electric fields of up to 300 V/m. A natural geomagnetic field that could be considered static exists, and it protects the life on earth from ionizing radiation of cosmic rays.
The magnitude of this field ranges from 30 μT at the equator to 70 μT near poles. Extremely low frequency electric and magnetic fields exists near electrical power lines. Common home appliances e.g. electric blankets, televisions, hair-dryers, computers, etc. produce ELF.
Non-ionizing radiation use is ubiquitous, however, their use is mainly below the limits set by inter-governmental agencies like the ICNIRP – International Commission on Non-Ionizing Radiation Protection, and the Institute of Electrical and Electronics Engineers (IEEE).
For example, in most homes the background magnetic fields will be less than 0.1 µT, electric fields may be 20 V/m or lower. These values may change when you are near some source appliances. Magnetic field values may rise a hundred times and the electric field several may rise up to five times.
Electricity industry workers
Directly below powerlines, magnetic fields reach as much as 20 µT and electric fields can be between several hundred and several thousand of volts per meter (~100 V/m – ~10 kV/m).
At the workplaces when using computers, printers and photocopiers workers are exposed to lower level fields. However, workers at the electrical supply industry may be exposed to magnetic fields in excess of 2,000 µT and electric fields up to 30 kV/m.
Controversy exists whether the non-ionizing radiation causes adverse health effects. It is not disputable however that the non-ionizing radiation results in biological effects.
A biological effect may not be necessarily harmful and occurs when exposure to electromagnetic field causes any noticeable or detectable physiological response in a biological body, such as alterations of the structure, metabolism, or functions of a whole organism, its organs, tissues, and cells.
Examples are heating effect, surface heating, electrical burn, and shock. The adverse health effects are often the result of accumulated biological effects over time and depend on exposure dose. They result in detectable health impairment of the exposed individual e.g. cancer.
Back to the mobile phone and 5G technology story. Where the alarmists contend that 5G will require many small cells, estimated at a transmitter for every two-ten homes, they do agree that the frequencies are still below ionizing range albeit more energetic.
Their assertion may be taken to mean the 5G is more hazardous as contrasted to more risky; the two means different things. A hazard can cause harm e.g. electricity, stress chemicals etc.
A risk is the chance that something will cause harm. In this sense we may say that mobile phone use, regardless the generation (1G, 2G, 3G, 4G and now 5G) is hazardous.
But is it risky? The WHO/International Agency for Research on Cancer (IARC) has classified radiofrequency electromagnetic fields associated with mobile phone use as “possibly carcinogenic to humans (Group 2B), a category used when a causal association is considered credible, but when chance, bias or confounding cannot be ruled out with reasonable confidence’’.
Dr. Kamweru, Paul Kuria is a senior lecturer at Chuka University, Kenya. His area of expertise, experience, and training is in Bio-physics and Material Sciences.