Are there any health effects to the tireless use of smartphones?
It’s a question worth exploring, especially with just how much Australians love smartphones, as proven by the fact that 88% currently own one.
One of the very first scientists to actually ask this question was a physiologist from Australia named Ross Adey. Back in the 1970s, when mobile phones had yet to gain the popularity that it has today, Adey was concerned over the frequencies that were being emitted by household appliances and electric power lines.
In experiments that were done in the United States, he discovered that rabbit brain tissue was sensitive to very weak electromagnetic radiation. Adey was a provocative figure until his passing in 2004, and few of his experiments have actually been simulated.
But in the decades since that first venture, a lot of time and money have been utilised into looking into how electromagnetic radiation might impact your health, ranging from sleep patterns to cancer.
What is electromagnetic radiation?
All around you is all kinds of electromagnetic radiation. And each day, your eyes pick up visible light, your bag is scanned by X-rays at airport security, microwaves heat your lunch and too much ultraviolet light gives you sunburn.
At its most basic, electromagnetic radiation is energy containing an electric field and magnetic field, which travel together, but perpendicularly, in waves.
Sometimes the length of these waves (or wavelength) is very short while others are much longer. It’s these long wavelengths, called radio waves, that are the electromagnetic radiation of choice for mobile phones and base stations.
Unlike shorter wavelengths, such as visible light, radio waves can go through walls. The longer the wavelength, the better it can go through solid stuff. Another term you be familiar with is frequency, which is the number of times a wave makes a full oscillation each second.
Frequency and wavelength are related. Wavelength is the speed of light divided by the frequency, so long wavelengths also have low frequency.
What are ionising and non-ionising radiation?
The radio frequency end of the electromagnetic spectrum is home to what’s called as “non-ionising radiation” according to Rodney Croft of the University of Wollongong and director of the Australian Centre of Electromagnetic Bioeffects Research.
It’s the high-frequency, short wavelength radiation, such as X-rays, that can affect your DNA and are linked to cancer. These waves are small enough and carry enough energy to knock electrons off atoms, ionising them.
Radio frequency used in mobile communications simply doesn’t have the energy to do that. But that’s not to say it doesn’t exert any effects on the matter it travels through.
“It’s an oscillating wave, which swings between positive and negative,” Croft said.
“As the positive bit moves towards a positively charged molecule, like water, it will cause [the molecule] to rotate a little bit. If you have a bunch of molecules rotating, that causes friction, and energy is given off as heat. It’s how a microwave oven works.”
Does anyone regulate radio frequency limits?
In Australia, mobile phone and base station exposure limits are established by the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) and regulated by the Australian Communications and Media Authority.
The ARPANSA standard keeps an eye out at how much energy a user absorbs from a mobile phone over time. The maximum limit is currently 2 watts per kilogram of tissue. Phone manufacturers usually indicate their maximum absorption rate in their manual.
According to ARPANSA, it’s “typically hundreds of times below the [ARPANSA] limits”.
What are the effects of mobile radio frequency on tissues?
So going back to the question that was posed early on: are you really microwaving your head each time you answer the phone? Perhaps a little bit, said Croft but definitely not enough to be worried about.
He and his team discovered mobile phone radiation exposure raises the temperature of the outer grey, wrinkled layer of the brain called the cortex, but it’s only “maybe about 0.1 degree, which is very small compared to the temperature variation the body normally has to contend with” he revealed.
“We do find that we get a slight change to thermoregulation, so the body, even with that small change, is sending a bit more blood out to the periphery to cool it, so your body doesn’t end up warming up.”
What about activity in the brain?
In a study that was published in 2008, he and his team held a Nokia phone to the head of healthy participants and evaluated their brain waves.
What they found were changes to a type of brain activity called alpha waves, which are linked with relaxation, but the effects were subtle: mobile phone exposure enhanced alpha wave activity by around 5%.
“Normally, if you close your eyes, you might double your alpha activity,” Croft said.
“So the [mobile phone] effect is very, very small relative to quite mundane functions, and that’s why we’ve been doing a bit of work to find out if there are any functional consequences. It could be that there is an effect, but it’s not strong enough to actually do anything meaningful to a person. So far, we haven’t been able to find anything.”