Mobile phones should carry a health warning, a charity caring for people with head injuries has said.

Headway National Injuries Association says not enough is known about the potential dangers of exposure to mobile phone radiation.

It wants mobiles to be regarded in the same way as tobacco and given a public health warning until their long-term effect on people's health is known.

Headway says more research should be carried out into the effects of cellular radiation and its effect on the brain when phones are held to the ear.

There are at present more than 15 million mobile phone users in the UK and, according to latest figures, one in four of the population own one.

While there are not thought to be dangers for analog phone users, the pulsed nature of digital transmissions is thought to be a possible health risk.

Some research has alleged that using a mobile phone for any more than 20 minutes at a time can increase the risk of cancers and other health problems.

The government has appointed independent experts to assess the health risks of mobile phones.

However, the mobile phone industry discounts such findings as inconclusive and points to opposing evidence which affirms their safety.

Research, from Bristol University, has found that using mobile phones may even speed up reaction times.

Bill Alker, from Headway, wants urgent action to limit the potential dangers posed by mobile phones.

Health implications unknown

He said: "Despite what the mobile phone companies say, there has been little work done on the long term human health implications of using them and we think there is enough evidence already available to cause serious concern.

"People are aware of possible boiling of the brain by microwaves emitted by phones or certain types of cancers, but what are the effects that have yet to be discovered?

"That is why we are calling for a health warning to be placed on mobiles so at least people are aware that the evidence is not conclusive and they can make up their own minds."

He added: "Before the real horrors were known about the risk to health of tobacco, people dismissed calls for warnings as scaremongering. What we say is that the same is true of mobile phones now."

The world's first civil lawsuit over the harmful effects of cellular radiation failed in February last year after magistrates in Gwent rejected a claim that mobile phones were unsafe.

During the case in Cwmbran, scientist Roger Coghill alleged that phone retailers had failed to disclose to customers the possible risks to health.

If his action had succeeded it would have resulted in all mobile phones sold in this country having to be labelled with the health warning Headway wants.

Users are protected

Mike Short, director of Cellnet and chairman of the Mobile Data Association, which represents the mobile phone industry, said the regulations in place were sufficient to protect consumers.

"A great deal of research has been done to establish how cellular phones can be used safely and I am confident there is absolutely no danger to health," he said.