Mobile phones and health seem, on the surface, unrelated. But as the use of phones continues to increase, especially with the coming of 4G and 5G technology, not only does this boost the number of mobile devices, but also the cell sites, or base stations used to connect them to telephone networks. The rising number of cell sites have caused people to worry about the dangers of the radio frequency they emit.
In May 2011, The WHO/International Agency for Research on Cancer (IARC) classified radio frequency electromagnetic fields under Group 2B, signifying that they are "possibly carcinogenic to humans", based on an increased risk of glioma, a malignant type of brain cancer that is associated with wireless phone use.
But there's no need to panic. Jessada Sivaraks, secretary to the vice-chairman of the Office of the National Broadcasting and Telecommunications Commission, said that the radio signals transmitted by ionising radiation such as infrared, visible light, ultraviolet, X-rays and gamma rays are more harmful than the non-ionising electromagnetic fields such as MRI, electricity, AM/FM radio and TV, as well as mobile devices and satellites.
Radio signals are generated by a variety of sources including mobile phone base stations, broadcast towers, radar facilities and remote controls, as well as via electronic equipment. Radio signals in the higher frequencies can generate heat in human tissue and may cause biological effects.
"People are normally afraid of signal towers but the towers don't send out the radio frequency, it's actually the antennas, thus people should be more concerned about them."
But at the same time, the transmission power of mobile phone base stations and antennas -- which are usually placed on top of advertising billboards -- are less strong than radio and television stations because the latter have higher frequency, said Jessada. The mobile phone base stations network is much denser than the network of radio transmitters. They can therefore be powered with much less energy and much less risk than radio and television transmitters. That means usually mobile phone stations can be safely installed in residential areas.
A mobile base station normally releases around 20 watts of power. For the 3G and 4G system, the power becomes less strong, so the height of the base stations are shorter when compared to those during the old days.
Jessada adds that "being closer to mobile stations carries less risk than television or radio stations, under the condition that they are of the same height and there is the same distance between users and the stations. However in the real world, no one designs television stations close to communities".
In daily life, one is faced with many kinds of radio frequency all the time. Radio frequencies can cause biological effects, for example, when a light bulb is pointed at a man, the heat can cause molecular changes within his body.
At present, there is no study indicating that radio frequency causes health hazards, however, there are studies that indicate that it can lead to biological effects. However, so long as the distance between the base station and users are appropriate, this is less of a concern.
What we should be more concerned about is something far less complicated, namely the heat that is generated from a device.
"When you are using your mobile phone for a long time, it will generate heat and that heat does cause a risk to your health," he said, noting that with applications that consume more power, the risks to health become much higher, as it causes changes in human tissues.
Some applications such as GIS consume the power of the device stronger than the voice application, so heat is one of the factors that users should observe when they deal with mobile devices.