Mobile phones 'could cause brain tumours in long-term users'

Scientists say possible dangers to children are also unknown - despite the millions of pounds spent during six years of research.

As a result, investigators say they cannot update "precautionary" advice issued in 2005. That warned parents to limit children's use of mobiles and said those under eight should not use them at all.

The results from the Mobile Telecommunications and Health Research programme show no shortterm harm to brain and cells among adults from mobile phone signals or base stations, or from signals used by the emergency services.

But the scientists found a "very slight hint" of increased cases of some type of brain tumours among people who had been using mobiles for more than 10 years.

The data was "at the borderline of statistical significance" but should be investigated further, they said.

Little research was commissioned on children, largely because the programme prioritised adult research for ethical reasons and on the basis that it would produce information relevant to the youngsters.

The researchers called the results "reassuring", but stressed that further studies would be needed for the foreseeable future as mobile phone use continues to grow.

MTHR chairman Professor Lawrie Challis admitted that only a small proportion of the research had included adults using mobile phones for longer than a decade, usually the time needed for cancer symptoms to appear.

He said: "We cannot rule out the possibility at this stage that cancer could appear in a few years' time.

"There is no way we can do that, both because the epidemiological evidence we have is not strong enough to rule it out and because most cancers cannot be detected until 10 years after whatever caused them.

"With smoking there was no link of any lung cancer until after 10 years."

Professor Challis said two other studies had failed to find any adverse effects of mobile use on children.

But he accepted they reacted differently from adults to a number of other environmental agents such as lead and ionising radiation. Further research in the pipeline would look specifically at children.

In the meantime, there was nothing in the report that would change advice to parents about minimising their children's use of mobile phones, he said.

The MTHR programme was set up in 2001, with joint funding from Government and industry totalling £8.8million. Professor Challis stressed that it was run by independent experts so the "public can believe the results".

There are now 70 million mobile phone handsets in the UK, and around 50,000 masts.

Both emit radio signals and electromagnetic fields that can penetrate the brain, and campaigners fear this could seriously damage health.

Roger Coghill, of Coghill Research Laboratories in South Wales, which specialises in the effects of electromagnetic radiation, said the new report made "selective" choices for research which ignored growing evidence about brain effects.

He said "Normal use of a mobile phone for a couple of minutes may not cause any health effects, but what about calls of 20 minutes? Tradesman are among those making heavy use of their phones.

"There are many omissions in this report, not least important work on children, and there are biological reasons why we should have concerns about children and old people."

Yasmin Skelt, of the campaigning group Mast Sanity, which campaigns against base stations, said: "Mast Sanity believes that pulsed microwave radiation at current exposure levels represents a risk to health and that the MTHR programme doesn't go far enough and has ignored many independent studies showing the risk.

"They have only reviewed their own small sample of studies and ignored the thousands of existing studies showing a risk."