SINGAPORE: By 2020, Singapore could see super-fast, more reliable wireless communication with the planned rollout of 5G networks.
It has been hailed as a technology game-changer, with supporters saying it will transform the way people live their lives, enabling things from self-driving cars to remote surgery.
Yet as with other mobile communication features, some concerns have been raised about potential radiofrequency exposure-related health risks. In Singapore, 24 of the 62 responses garnered by the Info-communications Media Development Authority's (IMDA) public consultation exercise were from people worried about the health risks of 5G networks.
IMDA, however, has said that the ambient level of radiofrequency radiation in Singapore is “very low” and typically below international guidelines.
So are there risks and where are the concerns originating from? Here's what you need to know.
WHAT IS 5G?
5G marks the 5th generation of mobile and wireless communication networks, promising super-fast connections and low latency (lag), among other benefits.
Like current networks, it relies on radio waves - part of the electromagnetic spectrum - to transmit and receive data via base stations and devices, to connect users to mobile communication networks.
The part of the electromagnetic spectrum which is used for communications is called the radiofrequency spectrum. It is divided into frequency bands, and 5G will use higher frequency bands than earlier networks to allow for better performance.
5G waves will have frequencies in the microwave region of the spectrum, with microwaves being a specific category of radio waves, covering the frequency range 1 GHz to approximately 100 GHz.
WHAT ARE SOME PEOPLE WORRIED ABOUT?
Like previous generations, 5G will also generate electromagnetic radiation. Some members of the public have voiced concerns about the possible impact on health this could have.
In May 2011, the World Health Organization’s (WHO) International Agency for Research on Cancer announced the classification of radiofrequency electromagnetic fields as "possibly carcinogenic to humans" (Group 2B).
This category is used when a causal association is considered credible, but “when chance, bias or confounding cannot be ruled out with reasonable confidence”.
Other things which fall into the Group 2B classification include pickled vegetables, while processed meats, tobacco smoking and alcohol have higher classifications.
SHOULD THEY BE?
WHO has established a programme to evaluate the health effects from exposure to electromagnetic fields in the range from 0 to 300 GHz - well above the planned frequency band for 5G networks (which today are planned around the 3.5 GHz and the 25 GHz and 28 GHz bands, also known as mmWaves).
According to the organisation, all reviews conducted so far have indicated that exposures to this frequency range do not produce any known adverse health effect. However, it added there are still gaps in knowledge that need to be filled “before better health risk assessments can be made”.
Similarly, Associate Professor M Prakash Hande from the National University of Singapore's Yong Loo Lin School of Medicine said that some health concerns could be valid.
"I believe that the concerns are valid. For 4G, it is known that continuous exposure can produce heat and oxidation in tissues," he said. "Safety studies were conducted on animals, human cells, insects and bacteria where 4G appears to show some harmful effects. Surprisingly, as far as I know no safety test has been done yet for 5G."
BUT WHAT EXACTLY IS THE RISK?
Radiofrequency radiation is considered "non-ionising". This type of radiation does not cause cancer by damaging DNA in cells the way ionising radiation such as X-rays or gamma rays does.
However, there have been concerns that some forms of non-ionising radiation could have biological effects that may result in cancer in some circumstances, according to the American Cancer Society.
The society also points out that if such radiation is absorbed in large enough amounts by materials containing water (for example food or body tissue), it can produce heat. This can lead to burns and tissue damage.
Specifically regarding 5G, researchers say that 5G radio waves do not get absorbed by the body but penetrate "only the outer layers of skin", according to Assoc Prof Hande.
They can travel a few miles but are easily blocked by objects, according to Assoc Prof Hande, and so relative to 4G, more 5G towers will need to be put in place "in order to achieve efficacy".
This is where the issue has become a topic of debate, according to IDC senior research manager Nikhil Batra.
"5G will require hundreds and thousands of these ‘small cells’ (a type of base station) to be installed in order to create a dense network, which will be different to current network generations, where signals were primarily relayed through large towers," he said.
However he said this does not change the fact that 5G waves will still be "very much" in the non-ionising group.
"Mobile networks and radiation have always been (under) discussion, but direct correlation between these mobile waves and impact to human health haven’t really been proven," he said. "If we look at the electromagnetic spectrum, the 5G frequencies will still very much be in the 'non-ionising' group, which are not absorbed by our bodies."
WHAT GUIDELINES ARE IN PLACE?
Exposure limits for electromagnetic fields are developed by the International Commission on Non-Ionizing Radiation Protection (ICNIRP), a non-governmental organisation recognised by the WHO.
According to the organisation, exposure to "high frequency" parts of the electromagnetic spectrum (which it defines as 100 kHz to 300 GHz) above a certain thermal threshold - taking into account duration of exposure - can lead to serious health effects such as heatstroke and burns.
However, acute and long-term effects of exposure below the thermal threshold have been studied extensively without showing "any conclusive evidence of adverse health effects", said the organisation.
It recommends basic restrictions so that this thermal threshold is never reached, and sets specific guidelines establishing limits to electromagnetic field exposure.
According to IMDA, the ambient level of radiofrequency radiation in Singapore is “very low”, and typically below 0.7 per cent of the ICNIRP guidelines. It says it will continue to heed these guidelines with the rollout of 5G services, and that along with the National Environment Agency, it will monitor developments and consult health experts as appropriate.