Compiled by DICK AHLSTROM
Why are we talking again about possible cancer risks linked to mobile phone use?
The World Health Organisation has renewed public concern about the risks associated with mobile phone use after an expert group carried out a fresh analysis of the scientific evidence.
The group announced on Tuesday that it now classes radiation coming from the phones as “possibly carcinogenic to humans”, with increased risk of brain cancers the danger.
I thought modern mobile phones were supposed to be safe?
For many years no link could be made between mobile use and bad health outcomes, but medical research into these risks never ended. This new analysis is based on more recent research and although the risks are small the expert group decided to upgrade mobile phone use to being a possible carcinogen.
What kind of cancer are we talking about?
Their concerns focus on glioma, a malignant type of brain cancer. One study they examined suggested a 40 per cent increased risk for gliomas in “heavy users” of mobiles, using them for 30 minutes per day over many years.
What causes the cancer?
No one has discovered how mobile phone radiation could trigger cancer. Many studies have shown that mobile use causes the brain to heat up because of the radio frequency energy given off by the phones. So far however, no clear link has been made between cancers and this heating up of the brain tissues.
How can they tell if something causes cancer if the risks are low?
There are several ways to do this. One involves asking patients who enter hospital with gliomas about their mobile phone use to see if many of them are heavy users.
Another way involves assembling a large random group of people and then monitoring them for a long time. The researchers try to make associations between illnesses that arise and behaviours that might have triggered the illness, for example heavy mobile use. These “epidemiological” studies are useful in picking up small risks so long as the number of individuals in the study is very large.
Another way is to expose cultured human cells or laboratory animals to mobile phone radiation, watching for any biological changes that have the potential to cause harm. These lab studies have not delivered any definitive answers so far.
Is there a risk for children?
Health authorities have always erred on the side of caution when it comes to mobile phone use by children. The department of health in the UK issued fresh recommendations last March that children 16 and under should use texting only and should speak over their mobiles only when absolutely necessary. Our Department of Health gives the same advice. Children should be discouraged from spending too much time on mobile phones.
Is texting bad?
You hold the phone away from your head when texting, so any exposure is reduced compared with speaking into the phone. The new research study did not express concerns about texting.
What about sleeping near a mobile phone?
Phones emit radiation when they are communicating with nearby antennas, so if the phone is not in use the radiation will not arise. But the phones also automatically “check in” with the nearest mast, even when not in use. This means if you sleep with the phone on a nearby night stand you will have at least some level of exposure. The expert group did not comment on this, however.
What about mobile phone masts? Don’t people protest about them?
Radiation going to and coming from the masts has been studied for years and so far no health effects have been found. This is because you have to be close to the radiation source for it to cause any problems.
The level of energy drops very rapidly the farther you are from the source. Move a mobile phone only one metre away and you receive only a tiny fraction of the original energy.
Typically mobile phone antennas are hundreds of metres away, so the energy they can deliver to you is very low indeed, even if you live near a mast.
But that is why hand-held mobiles are a potential problem, because they are usually pressed close to the ear when in use, maximising the energy delivered to the brain.
So am I better off with a hands-free kit rather than keeping the phone against my ear?
Yes, if you want to reduce the energy being delivered to the brain. Fully hands-free units as used in cars involve mounting the phone in a cradle and using a speaker and microphone to support use without touching the mobile.
There are also “wired” hands-free sets where earplugs, as on an MP3 player, are used to move the phone away from the head. There has been speculation that the wires could channel radiation back into the ear but there is no data to show this could cause harm.
Another alternative is to use the phone on speaker mode and hold it a short distance away from yourself to reduce exposure.
Is it bad to carry a mobile phone in your pocket? Could men be at risk of developing testicular cancer?
Studies so far have not been able to make this connection, so either the risk is very small and has not been shown to exist yet or there is no risk.
What about my wireless phone at home? Is that dangerous?
Wireless home phones work at lower power levels because distances to the base unit are shorter. There is no research to show that they are harmful.