A few years back there was an almost global panic about radiation from mobile phones that can potentially fry brains and cause cancer. A mass of research has been carried out since which laid to rest a lot of fears and concluded that harm resulting from mobile phone use is unlikely. But that said there has been no long term research looking at the effects of mobile phone use over a 20 year period. With mobile phone use now a fact of life and set to grow even more with the advent of mobile computing should we reconsider the facts given that mobiles do emit radiation, albeit in very small doses?
You may recall several years ago quite a media blitz on radiation emitted by mobile phones. It was dubbed SAR because the effect of radio waves on your body is measured using specific absorption rates (SAR).
Mobile phones emit a radio frequency electromagnetic field and these transmit in all directions to find the nearest base station. This means that some of the radio waves will be directed at your body when you use a mobile phone. As such radio waves are absorbed into your body tissue as energy, which adds to the energy being produced by your body's metabolism.
Being zapped by radiation certainly sounds ominous and perhaps many of us have vague fuzzy knowledge about the radiation that blasts out of nuclear devices. We’re all familiar with the apocalyptic scenario in which people out of range of the explosive impact of a nuclear device ultimately succumb to radiation poisoning.
But clearly mobiles are not nuclear devices and the many SAR studies concluded that the radiation emitted by mobile phones was negligible and unlikely to cause harm.
This research pointed out that some people experienced raised blood pressure when using a mobile but keep in mind our blood pressure changes regularly throughout the day and is even affected by tasks such as speaking.
Other effects included mild fatigue after prolonged use and also brain warming when a phone is used for a lengthy period though the heat disperses as soon as you stop using your phone. It causes no harm.
That said the pace of mobile phone technology is advancing at a far quicker pace than the research required into the potential harm they can cause. So being circumspect, more research is needed before we can know for certain the effects they have on human health.
Importantly there has been no research to measure the potential health impact from long-term exposure such as using a mobile phone for more than 20 year. This is clearly needed, and apparently is being carried out, given the explosive and global use of smart phones in the last few years.
What is radiation?
Essentially radiation is energy that's travelling through space in the form of waves or particles. It occurs naturally and has always been around. We've evolved with it and we're bombarded with it in one form or another every day of our lives with these waves coming from the earth, from outer space and even from within our own bodies. This is known as background radiation and it’s ubiquitous, whether its cosmic rays or radioactive materials contained in the earth and in living things.
There are others types of radiation, but electromagnetic radiation, the type emitted by mobile phones is created when radiant energy is released by certain electromagnetic processes. This is what researchers measured in their studies of mobile phone usage.
Importantly, the World Health Organization classified radio frequency electromagnetic radiation (mobile phone radiation) in a category known as Group 2B which suggests it is possibly carcinogenic. However, to put the classification in context, Group 2B also includes coffee and vehicle exhaust emissions. In short, the classification is saying that if the threat of cancer from mobiles exists, it is not a large one.
How do mobiles emit radiation?
- Most phones operate on several networks such as 2G, 3G and 4G and at different frequencies, that is, the network band used to send and receive signals. This means a single phone can emit different levels of radiation depending on which network and which frequency is being used on.
- Phones emit radiation when they're transmitting signals from your handset to a cell tower (base station). The harder a phone has to work to send a signal, the more radiation it will emit. So if you find yourself in a remote rural location a long way from a cell tower, or there are lots of physical obstacles, the amount of radiation emitted would be higher than if you were close to a cell tower.
- How you use the phone also affects the amount of radiation emitted. It takes more power to emit a voice signal and less to send text messages.
The early SAR tests focused on emissions when the phone was held to the ear. Today people more frequently keep their phones in their pockets and use headsets. This means there is less radiation to the brain area but more to the lower body.
The type of body tissue absorbing the radiation can affect how much radiation goes into the body. For instance skin and muscles absorb more radiation than fat and bones. This raises concern about exposure at the waist, particularly to reproductive organs that don't have a protective layer of bone like the skull shielding the brain
Also, the further away the phone is from you, the less radiation you'll absorb from it. Holding the phone 25 centimetres away can reduce radiation exposure by a factor of 400.
Where ever you stand with mobile phone SAR, or more likely you haven’t given it much thought, it’s worth keeping in mind that more long term research is being carried out including on other sources of electromagnetic radiation including Wi-Fi and utility smart meters. Clearly this suggests uncertainty.
If you do have concerns there are a few simple steps you can take to reduce the levels of radiation you absorb from using your phone:
- Rather than place your phone under your pillow when going to bed, leave the phone at a bedside table.
- Hands free headsets dramatically reduce radiation emissions into the brain
- Try not to chat for hours on end or, if you must, get a hands free kit
- There are devices on the market that help reduce the emissions of radiation. That said be aware of manufacturers using scare tactics to market their products.
And of course it's always sensible to take precautions where children are concerned. Children tend to absorb radiation at three times the rate of an adult and as such their developing brains, nervous systems and bodies are far more susceptible to radiation effects than adults.