Mobile fears of world health leader

Mobiles are popular among children

Parents have been warned against letting their children spend too much time on their mobile phones by the head of the World Health Organization (WHO).

"I would be cautious about letting children use mobile phones for hours every day, because we don't know enough about the damage," said WHO Director-General Gro Harlem Brundtland.

Some tests have shown higher electromagnetic waves in places where mobiles are frequently used.

But there is no conclusive scientific evidence to prove any long-term negative effects of mobile phone usage.

Mobile headaches

Gro Harlem Brundtland does not own a mobile phone and has banned anyone from using them in her Geneva office.

Brundtland does not own a mobile

She says this is to protect herself from electromagnetic waves, which she argues give her a headache.

"If you enter my office, you are invited by me. No one who is invited would like to give me headaches," said Ms Brundtland at a news conference in Oslo, where she attended an international conference on cancer.

Since mobile phones are a relatively new technology there has been no research examining the long-term effects of using handsets.

Inconclusive results

Two years ago, a UK Government inquiry concluded that mobile phones posed no provable health risk.

But it did urge caution over the use of mobile phones by children until more was known about their impact on health.

Recent research carried out by scientists in Finland suggests that radiation from mobile phones causes changes in the brain.

They found that exposing human cells to mobile phone radiation damaged the blood-brain barrier, a safety barrier in the body that stops harmful substances in blood from entering the brain.

Experts have suggested that any perceived risks can be kept to a minimum by keeping mobile phone conversations short and using hands-free kits for longer conversations.