Mobile phones and health: what every user should know
A leading scientist has urged parents to stop children under 8 using mobile phones, arguing that
there is still no proof they are safe. So what is the truth?
IT IS PRECISELY the kind of sweet, colourful button-laden gadget that children adore. The Mymo,
launched in the autumn of last year, is designed to be worn as a necklace but is marketed to parents
as a security device. It has a locator that works inside the UK and also doubles as a mobile phone,
into which parents can pre-program up to five numbers.
Since it was targeted at four to eight-year-old children, it is also precisely the kind of gadget that Sir
William Stewart never wanted to see. In 2000 he chaired an influential inquiry into the effects of
mobile phones on health that concluded: “In line with our precautionary approach, at this time, we
believe that the widespread use of mobile phones by children for non-essential calls should be
This week, Sir William, now chairman of the National Radiological Protection Board, as well as the
Health Protection Agency, strengthened his warning, saying that children under 8 should not be
allowed to use them. “I don’t think we can put our hands on our hearts and say mobile phones are
safe,” he said at a press conference on Tuesday. While there was still no firm evidence that the
gadgets caused harm, he said, his concerns had grown.
Sir William, who uses his own mobile sparingly and whose grandchildren do not own one,
advocated caution by all phone users but voiced particular worry over their ubiquity among
children. His reminder, which this week prompted the British company behind Mymo to withdraw
its product pending further research, comes amid growing evidence that British parents are ignoring
safety advice. Studies suggest that a quarter of primary schoolchildren — and 90 per cent of under-
16s — have their own phone. So, what is the truth about mobile phones and health? Below is a
summary of the take-home messages of the most influential reviews, studies, reports and
investigations that have been carried out over the past 20 to 30 years. Many authoritative studies —
instigated as a result of the original Stewart report in 2000 — have not yet been completed.
WHY IS THERE CONCERN ABOUT THE EFFECT OF MOBILE PHONES ON HEALTH?
Mobile phone technology is relatively new. As the World Health Organisation (WHO) puts it: “The
current debate is centred on whether long-term low-level exposure can evoke biological responses
and influence people’s wellbeing.”
This exposure is from both base stations and phones themselves (handsets). Both base stations and
handsets work by transmitting and receiving radio waves (mobile phone frequencies lie at the
border between radio waves and microwaves, which is why they are sometimes called microwave
emissions). Because handsets are held close to the head, there have been suggestions that the
emissions may harm the brain, inducing cognitive damage and even brain tumours.
Incidentally, the WHO makes it clear that a biological change is not necessarily a health hazard,
pointing out that actions such as eating an apple induce biological change.
In 1996, the WHO instituted a review of all the available literature — around 25,000 papers —
covering the biological and medical effects of non-ionising radiation (which includes the
frequencies used in mobile phone technology).
The review was called the International EMF (electromagnetic fields) Project. It said: “Based on a
recent in-depth review of the scientific literature, the WHO concluded that current evidence does
not confirm the existence of any health consequences from exposure to low-level electromagnetic
fields. However, some gaps in knowledge about biological effects exist and need further research.”
The view of the WHO that there are as yet no proven adverse effects — but that there is a real need
for further research — has been echoed by almost every other research group in the nine years
Two months ago, the WHO said that further research on children, who are prolific users of mobile
phones, should be a “high priority”. This view — that children are especially vulnerable because of
their thinner skulls and developing nervous systems — is also shared by other academic groups.
However, brain cancer — which would be a prime target for study — is regarded by the WHO as
too rare a disease to be useful in drawing any conclusions about the carcinogenic effects of radio
TELL ME MORE ABOUT RADIO WAVES
Radio waves are sometimes called electromagnetic energy or electromagnetic fields (EMF). They
form part of the electromagnetic spectrum, which includes visible light, microwaves and X-rays.
You are exposed to electromagnetic energy when you switch on a light or turn on the television. It
is known that electromagnetic energy has a heating effect — this is employed by microwaves to
warm up food — and guidelines for human exposure to radio signals are deliberately set sufficiently
low enough to not cause heating.
SINCE THE WHO REVIEW, HAS THERE BEEN ANY EVIDENCE THAT MOBILE PHONES
OR BASE STATIONS ARE A CAUSE OF ILL-HEALTH?
The Stewart report (or, more properly, the report of the Independent Expert Group on Mobile
Phones chaired by Sir William) was a landmark review of the health effects of mobile phone
Released in 2000, it addressed the emissions from both handsets and base stations, although at that
time concern was focused on handsets, which are held close to the head. The Stewart report did not
find a higher incidence of brain tumours, cancers or other diseases among mobile phone users.
It noted that, while handsets in the UK were comfortably within exposure guidelines, emissions
below guideline levels could warm brain tissue (although not sufficient to cause disease or injury).
However, the report noted gaps in the scientific literature and, accordingly, recommended a
It advised parents to limit mobile phone use among children, whose developing nervous systems
might be more at risk and who have a long lifetime of exposure ahead of them. The Stewart report
recommended that children text-message, rather than phone.
Text-only phones are not available, although it is possible to adapt handsets to bar outgoing calls
(except emergency calls) and allow incoming calls only from designated numbers.
The NRPB report issued this week by Sir William again urges parents to adopt a precautionary
approach. This new report mentions four studies that, while inclusive, have raised alarms.
In January last year, the Advisory Group on Non-Ionising Radiation, an independent panel that
reports to the National Radiological Protection Board, reviewed the medical and scientific evidence
that had accumulated since the Stewart report and found that there was no evidence that mobile
phone use was linked to cancer. The group concluded: “The weight of evidence now available does
not suggest that there are adverse health effects from exposures to radio frequency (RF) fields
below guideline levels, but the published research on RF exposures and health has limitations, and
mobile phones have only been in widespread use for a relatively short time. The possibility
therefore remains open that there could be health effects from exposure to RF fields below
guideline levels; hence continued research is needed.”
Emissions values for every mobile phone should be listed on the packaging as a SAR (Specific
Absorption Rate) rating, which measures energy absorption in the body. Lower SAR values mean
IT SOUNDS AS IF MORE RESEARCH IS NEEDED?
There is a £7.4 million British effort under way, called the Link Mobile Telecommunications and
Health Research Programme. Half the funding for the programme, launched in 2001, is coming
from the mobile phone industry and half from the Government.
The research programme is investigating, among other things, the effect of mobile phones on blood
pressure and brain function of users; the incidence of brain cancer and leukaemia in both phone
users and young children who live near base stations; how much energy radio signals can deposit in
the body, and where; whether hands-free headsets affect drivers' performance; whether pulsed
signals produce different biological effects from continuous signals; and nwhether some individuals
are hypersensitive to electromagnetic signals, such as those produced by base stations and mobile
phones. Results will emerge over the next few years.
ARE HANDS-FREE KITS SAFER?
This week’s NRPB report cites research suggesting that the use of such kits could reduce exposure
around the head by a half. Sir William is calling for standardised testing of all kits, and for the
results to be made available to buyers.
WHAT ABOUT 3G TECHNOLOGY?
The NRPB report makes the assumption that, since 3G base stations cover smaller geographical
areas, they will radiate the same or less power than a 2G (or GSM) base station. (GSM is the most
common mobile standard in the world, used by a billion people.)
The NRPB has measured exposure at a small number of 3G sites and found them comparable to
others; however, it recommends detailed monitoring as more 3G base stations are rolled out.
However, Sir William notes that one study suggests 3G handsets may affect brain function. The
study needs verification and replication but should not be ignored.
ARE WIRELESS DEVICES, SUCH AS BLUETOOTH, SAFE?
This is, according to the NRPB, an unclear area. It notes the proliferation of new technologies such
as 3G, Bluetooth, wireless local area networks and even radio tagging devices. Generally, wireless
networks have a relatively low power output. It is uncertain how all the disparate signals and power
outputs interact. The NRPB recommends more research on both this and any possible biological
effects caused by widespread background exposure.
CAN PEOPLE REACT DIFFERENTLY TO ELECTROMAGNETIC FIELDS?
Possibly, and work is under way to establish whether a condition called electromagnetic
hypersensitivity syndrome (EHS) exists.
The UK expert in this area is Professor Elaine Fox, of Essex University. In various countries,
between 2 and 6 per cent of the population report symptoms ranging from insomnia and loss of
libido to depression and skin complaints.
Fox has just begun a two-year investigation to see whether the sufferers and non-sufferers do react
Members of Fox’s team have encountered sufferers who reject electrical appliances, such as
microwaves, TVs, radios and mobile phones, because of their condition.
The most seriously affected shield their houses with an expensive metal mesh that blocks out EM
The view of the WHO is that “there is little scientific evidence to support the idea of
electromagnetic hypersensitivity”. However, it advocates more research. It is a recognised disorder