5G represents the fifth generation of mobile network technology, and it promises to be as much of a leap forward as 4G mobile broadband was back in 2011.

As the rollout proceeds, however, it’s become a focal point for longstanding concerns about the health effects of electromagnetic radiation.

“I’m very concerned about 5G. I already get headaches from 4G and wifi,” Oliver in Mackay wrote in to Hack.

A Sydney resident told the ABC recently: “We don’t want it here. It causes us great anxiety that this thing is going to be running 24-7.”……

Australian and many other national health regulators say 5G is safe, while some recognised researchers urge caution.

What is 5G?

As with previous generational upgrades, the new tech is much faster than the existing network: Telstra recently achieved network speeds of around 3Gbps – about 60 times faster than 4G.

It’s likely to be used for driverless cars and virtual reality, as it allows much larger amounts of data to be transferred with less time between the signal being sent and received.

It achieves this speed and bandwidth partly through using higher frequencies of electromagnetic waves than 4G or any of the previous mobile networks.

To understand what this means, let’s go back to high school physics: Mobile phones and mobile towers emit radiation, as do radios, microwaves, X-ray machines, and the sun.

Radiation can be broadly divided into ionising and non-ionising types.

Ionising radiation is powerful enough to damage DNA, which is why you have to be careful about too much sunlight or too many X-rays.

Non-ionising radiation doesn’t have enough energy to break our DNA, and therefore we have traditionally thought it cannot cause cancer.

5G-type electromagnetic waves are a higher frequency than 4G (and therefore further up the spectrum towards X-rays) but still on the non-ionising side.

Because they have shorter wavelengths, the waves are less able to penetrate solid objects (e.g. sunlight can’t go through a wall, but radio waves can).

For this reason, 5G requires heaps of suitcase-size cell boxes to boost the signal and direct it around corners and other obstacles. These will be a lot more numerous than 4G towers.

Leszczynski says these studies are evidence it also has a non-thermal effect.

If that’s true, it would overturn the scientific basis of our current limits on mobile phone radiation exposure.

However, these studies are limited. As Leszczynski says: “This result is from epidemiological studies that can show only whether there’s an increase or not an increased risk of developing disease.

“They cannot demonstrate in particular this radiation has caused this cancer.”

His point is that we just don’t know what exactly is going on, and therefore we should be cautious.

What effect does it have?

One reason we don’t know is because it’s very difficult to study the long-term effect of cellphone radiation on humans. Unlike, say, smoking, we’re unable to expose one group to radio frequencies, and then compare their health with the non-exposed population.

Cellphone radiation is already everywhere, plus the frequency of radiation has changed rapidly over a relatively short period of time. The way we use our phones has also changed (for example, now children are more likely to use phones than before).

That leaves studies on animals: In 1999, the US FDA asked the National Toxicology Program (NTP) to study the toxicity and cancer-causing capability of cellphone radio-frequency radiation.

This was a US$30 million undertaking. The scientists had to have special chambers built in Switzerland so they could control exactly how much radiation the animals were getting.

The draft findings came out nearly 20 years later, in 2018.

It found that several rats and mice that had been blasted with with large amounts of radiofrequency electromagnetic radiation for two years exhibited tumours.

“We believe that the link between radio frequency radiation and tumors in male rats is real, and the external experts agreed,” said NTP’s John Bucher in a statement.

But the researchers struggled to form conclusions from the study.

The rodents were exposed to much greater levels of radiation than a person would using a mobile phone or another consumer device.

There was also no clear linear relationship between higher radiation exposure and more cancer.

Also, humans absorb radiation differently to rats and mice.

Given this uncertainty, it’s a big leap to pause the technology without any evidence of ill-effects.

A huge chunk of the population has been using mobile phones for over two decades, and there hasn’t been an observed increase in cancer rates.

Professor Rodney Croft from the Australian Centre for Electromagnetic Bioeffects Research at the University of Wollongong argues we can be confident in the relative safety of non-ionising radiation.

“The reality is we know a lot about the mechanisms involved with the interactions with electromagnetics fields and the body,” he told Hack.