The attachments we tested didn't reduce the radio waves picked up inside our dummy head. Two of the three shields did - but as they reduced the signal, the transmitter would just instruct the phone to increase its radio wave output. And the hands-free kits made things worse by conducting radiation straight into your ear.
So, given that no one knows for sure whether there is a health risk, the only thing to do if you are worried, is to cut down on your phone use (especially if you have an analogue phone). And until more evidence is available, it might be prudent if the UK were to adopt the lower ICNIRP limits on permissible radiation levels.
People who live or work near transmitter masts may also have legitimate health worries. The evidence suggests this is unlikely, but not impossible.
However, if a company wants to put a mast on your home or children's school, find out why. Make sure it has explored all the options - there is an obligation to share existing sites with other networks, so make sure this has been looked into. To try to stop the mast going up, talk to your MP and the local paper.
And until there is conclusive evidence one way or the other, the companies should consult tenants and leaseholders, as well as freeholders, before putting a mast on their roof.

Think again if you use a hands-free kit to protect yourself from mobile phone radiation - the two we tested increase the radiation levels inside your head compared with holding the phone by your ear. Shields that claim to block radiation also offer no protection.

It's not surprising that people use these devices. With headlines like the ones below, it sounds reassuring to use a device that keeps the phone away from your head. But, in reality, the earpiece wire on the hands-free kits we tested acts as an aerial - and channels three times as much radiation to your head. Although we tested only two kits, our experts agree others could suffer from the same problem.
We confronted Carphone Warehouse, which sells one of the kits we tested, with the evidence. Its factsheets tell consumers who are concerned about radiation to 'use an earpiece attachment so you are not using the phone directly next to your head'. But the response to our findings was pretty disingenuous: 'the sheets simply state the facts - it is a fact that earpieces remove the phone away from the user's head'. The factsheets don't, however, state the fact that this can lead to higher radiation levels. Carphone Warehouse says it is revising the factsheets to say it can't comment on the effectiveness of these products - and promises to include our findings.

Some scientists dispute non-thermal effects, saying they haven't been proved by laboratory experiments. And, if they exist, no one is sure what level of radio waves causes them. Typical of the often-reported research is a survey of people with brain tumours in Sweden. This found they were more likely to have the tumour on the side of their head on which they said they held their mobile phone. But the study didn't find a higher risk of cancer among mobile phone users generally, and scientists criticised it for relying on people's memory, and the small number of people asked.

The Royal Society of Canada (RSC), a leading body of scientists, reviewed a large number of research studies last year, and a spokesman said it had found 'increasing evidence' that non-thermal effects exist. However, the RSC still says that it isn't yet clear whether radio waves at low intensities cause serious health problems. Many of the studies which show a link between mobile phones and cancer haven't been repeated - so the link could just be coincidence.
We've looked at eight major reviews of all the scientific evidence, including the RSC's. They all conclude that, as the research stands at the moment, no one has proved there definitely isn't a link between exposure to radio waves and cancer or gene damage, but there is only a small likelihood that a link exists.
Phone companies' views
Unsurprisingly, this is the view of mobile phone companies. The Federation of the Electronics Industry (FEI) usually speaks for the mobile phone industry on radiation health risks. It says there is no 'consistent' evidence of any harmful side effects and that it 'will continue to support independent research in this area, and will share information in an open and honest way.'
For those who are still worried, FEI says 'people are free to buy hands-free kits or shields, although we would advise them to beware of products that make false claims and that are not approved by handset manufacturers'. This statement is, perhaps, ironic, given the hands-free kits we tested are sold by the networks or major high-street retailers.
Finding a definitive answer
We should have a better idea of any ill effects in the future. The International Agency for Research into Cancer is investigating whether mobile phones increase the risk of cancer in adults. Another project in six European countries is looking into any cancer-causing effects on animals. And the World Health Organisation is reviewing the evidence to come up with a universal standard for mobile phone emissions. For now, though, if you think there are grounds for concern, you're best off reducing your phone use.

Even though the effects are disputed, there are still limits on the levels of radio waves that phones can emit. In the UK, the National Radiological Protection Body (NRPB) sets these. It says the research shows that radio waves from mobile phones don't have enough energy to damage genetic material like DNA, and therefore can't cause cancer. However, it accepts that heating effects could be a problem, and sets the limit so that radio waves from a mobile phone should not cause any temperature rise.

In practice, UK phones emit only a fraction of this recommended level - older analogue phones put out about a third of the limit and newer digital phones just a tenth, although this varies between models.
However, the International Commission on Non-Ionising Radiation Protection (ICNIRP) recommends a lower limit than NRPB's. If the ICNIRP limit was used, current digital phones would emit about half the recommended maximum - but some older analogue phones would exceed it.

It's not just phones that give off radio waves. Mobile phone masts - also known as base stations or transmitters - do so too. And last December, Gillian Taylor (pictured, right) was given just a couple of days' notice about one being erected on her roof. When she bought her top-floor flat seven months earlier, no one told her that the freeholder had negotiated a contract with One2One, and now there's a mast directly above her flat. Gillian says: 'I'm a nurse, and I'm very concerned about the potential health effects posed by radiation, and in particular the link to cancer.'

Why there are health concerns
Worries about masts result from research in the UK and Australia, which suggests people who live near TV and radio broadcast towers are more likely to have leukaemia. As with the phones themselves, the evidence is unclear and follow-up studies have contradicted the original claims. Many scientists believe the power from masts is too low to cause health hazards, as long as people are kept away from direct access to the antennas. Base stations don't deliver a large amount of radio energy to small areas of the user's body and so can't create hot spots in the way that phones do.
Not everyone is convinced. Campaign groups such as Friends of the Earth Scotland (FES) say that there may be health implications for people living or working near transmitter masts. And they are concerned that, as with phones, the NRPB guidelines in the UK are higher than levels in other countries. They've received anxious enquiries from tenants living on the top floor of council-owned flats who are worried because they have four or five masts sited on top of their building. FES wants the government to make sure transmitter masts are sited away from schools, hospitals and residential areas.
These objections to mast sitings aren't just limited to Scotland - many local groups are campaigning against masts in their area. In its submission to a House of Commons investigation last summer, Northern Ireland Families Against Telecommunication Transmitter Siting (NIFATT), a coalition of more than 70 community groups, also suggested the government should implement a buffer zone between homes and masts, and encourage the sharing of sites between network operators.
When companies erect masts
Mobile phone networks must follow certain procedures if they want to erect a new mast. To erect one on existing buildings, however, they can go direct to the local planning authority, which has 28 days to refuse or accept the application. As Gillian Taylor found, there's no compulsion to consult people living in the building if they don't own the freehold.
NIFATT wants this shortened application procedure abolished, and wants mobile phone network operators to go through the full planning permission procedure. This would double the length of time from the application to the final decision, and give more opportunity for local consultation.
For now, though, the only option for Gillian and the other residents of Buckingham Lodge is legal action against their freeholder. Haringey Planning Department says they can't do anything to stop the mast going up until the law changes.
The Federation of the Electronics Industry claims there are benefits from more base stations: 'Base stations do not have limitless capacity, so where demand is often heavy, the operators are installing more of them. This means that cells are getting smaller, which in turn means that the power emitted by base stations is getting lower, as there is less area to cover.'
Orange is one of the few companies that would speak to us directly. It echoes this reassurance and says its masts' emissions are far below recommended limits. Its opinion is similar to the industry view on the handsets: 'There is no conclusive evidence that makes a link between exposure to radio waves [or] transmitter masts and long-term public health risks.'
This is true as far as it goes - research shows low levels of radio waves from distant masts are unlikely to cause health problems. But a lack of 'conclusive evidence' is little reassurance for people living, working or going to school directly under a base station. Until the research tells us more, it may be prudent for masts to be sited away from homes and schools.
And these masts could be closer than your think. Some, like the ones on Gillian Taylor's flat, are obvious. But in rural areas, phone companies disguise masts as trees. And microcells, a new type of transmitter, look like small boxes. They are attached to walls or lamp posts in areas of high demand like high streets and shopping centres - there are cells every few hundred metres along London's Oxford Street, for instance.

We'll have to wait several years for the results from the international research that's under way. But there could be changes before then to UK rules. The Department of Health commissioned independent experts to report back by the end of March, although the result isn't yet known. And the British Medical Association, the professional association for doctors, is calling on companies to give consumers more information about hands-free kits and shields. It also wants better monitoring of diseases, to pick up any increases associated with mobile phone use.

But for now, until the international studies report, there's no way to know whether mobile phones are perfectly safe, or whether they are like cigarettes - a health risk that's suspected long before it's proved.

Many people have devices to keep radiation away from their head - hands-free kits, shields and attachments. Some of these are sold by UK retailers or packaged with mobile phones. Others are available by mail order or the internet.

But the ones we've tested have one thing in common - they don't work. The hands-free kits channel more radiation to your head, the attachments don't work at all, and even when shields cut down the radiation level, your phone is likely to boost its output to make up for this, which can leave you in a worse position.
Most of the manufacturers disputed our findings. However, where they've made a specific health claim that we think is untrue, we've reported them to their local trading standards department.

To measure radiation levels, we used a laboratory with an international reputation for mobile phone tests. It tested two hands-free kits, two attachments and three shields.

The lab transmitted a constant signal to the mobile phones in a room with walls that absorb radio waves - so readings weren't confused by external mobile phone transmitters. And we tested the shields and the hands-free kits on two different phones, to make sure the results were consistent.
To measure the radiation inside the head - the near field - the lab used a probe inserted inside a dummy head filled with a material that simulates the properties of flesh.
We also measured the signal being broadcast to the network transmitter - the 'far field' - using another distant probe. For a product to be any use, it needs to reduce the near field without affecting the far field - otherwise the transmitter would register only a weak signal and instruct the phone to boost its power level. This would increase the radio waves in the near field, too.

If you see people walking down the street talking to themselves, the chances are they are using a hands-free mobile phone kit. These sound like a good idea, as they keep the phone and, you might think, the radiation, away from your head. But if you use one to protect yourself, you'll be alarmed by our findings.

BT Cellnet Hands-free Accessory Kit for Phillips Savvy 14.99 This doesn't make a specific claim, which is a good job - it tripled the levels of radio waves inside the head. Phillips told us that its tests found a reduction in radiation levels - but when we carried out the tests a second time to check, we still found three times the level of radiation
Carphone Warehouse Hands-free earpiece for Ericsson A10185 14.99 In its leaflet Mobile Phones and Health, Carphone Warehouse says that if you are worried about radiation, an earpiece attachment like this kit means the phone won't be adjacent to your head. In practice, it tripled the radio waves reaching the brain.

Other hands-free kits could have similar effects. These results took us by surprise - by the time we discovered them, it was too late to test more kits for this issue of report. But looking at several other kits, our experts thought they would also conduct the radiation. You can make a hands-free kit that doesn't act as an aerial - but this would need to be taken into account when designing the phone.
We asked some manufacturers about this. Nokia said its hands-free kit cuts radiation levels in independent tests - but wouldn't show us the results. Ericsson and Panasonic said their phones and hand-free kits meet relevant standards - but didn't say whether the kits boosted or cut radiation reaching the head.

These attachments are designed to stick on the phone but, before we tested them, our experts were baffled as to how they might work. There are materials that absorb or reflect radio waves - iron-based materials can absorb magnetic fields, for instance - but they won't absorb the electric fields generated by a mobile phone. And even if they did, sticking them on your phone or aerial isn't going to help.

Tecno AO Electromagnetic Bioprotection Antenna 29 This comes with a lengthy and confusing booklet that claims the antenna will protect you from the 'harmful athermal effects from extremely low-frequency radiation'. However, a mobile phone gives out mainly high-frequency radiation, so this approach seems strange. And whatever it does, sticking it on the back of the phone, as shown in the booklet, won't absorb any radiation. Our verdict Unsurprisingly, our tests showed no reduction in radio waves.

Zeropa Electromagnetic Field Absorber 24.95 Britannia Health claims the Zeropa 'substantially reduces the amount of electromagnetic radiation penetrating the head' and says it is made from a 'patented compound of ceramics'. Again, it sticks to the base of the phone's antenna, or on the phone body very close to the base. The manufacturer doesn't give much detail about how it works, but told us the claims were based on independent research. Our verdict We thought it unlikely that this would have much effect, and our tests showed no reduction in radio waves.

Some materials can block radio waves, so if you put them round your phone, it might sound like they could block radiation reaching your head. One big flaw with this idea is that covering your phone like this would stop radio waves altogether, so the phone wouldn't work. What's more, cases made of these materials have to have openings so you can put your phone in - so they leak radio waves. We put three to the test to see what effect they have.

AEGISGuard phone radiation shield 34.95 Aegis says the 'proprietary materials used in AegisGuard Phone radiation shields deflect up to 99.9 per cent of radiation emitted by a properly operating mobile or cellular phone away from the head and neck of the user without affecting reception'. It says the case is made of material designed to 'deflect' radio waves. Looking at it, however, it shields only the body of the phone, so you wouldn't expect it to affect the radiation from the phone's aerial - which makes it unlikely that it could protect the user. Our verdict It's true that this didn't affect the signal transmitted by the phone, so it won't affect reception. However, it also didn't reduce the signal picked up by the probe in our dummy test head. It won't give you any protection from radiation.
Microshield phone radiation guard 29.95 Microshield says 'Independent tests ... have shown that Microshield reduces unwanted microwave absorption into the user's head by up to 99 per cent.' This product has a retractable metal 'finger' (an aerial guard) that has to be raised into position in contact with the aerial to disturb the radio waves. It's made from a material designed to absorb or deflect radio signals. Our verdict The Microshield case reduces the signal by 70 per cent, but only in one direction - depending on where the transmitter is in real life, this could just make your phone boost its output to compensate. So instead of protecting you from radiation, this could make things worse. Microshield disputes our findings, and claims that it made a mistake and sold us the wrong covers.
Radiation Rabbit 388 Case 24.99 The Radiation Rabbit doesn't make any specific claims, although its name suggests it has an effect. The case extends to partially cover the phone's aerial. It did reduce the level of radio waves from our phone, but by less than 50 per cent. In real life, this could just lead to your phone boosting its signal and using more power, so you can continue to make calls. This means that your phone could give out more radio waves than without the case.