Mobile facts

There are 20,000 masts in UK 100,000 could be built over next 5 years Schools can receive �10,000 a year to take a mast 24 million Britons have a mobile phone

At each location, the radiation was found to be well below national and international guidelines set by scientists.

In fact, in some tests, pupils were found to be absorbing more radiation from masts more than 300 yards away than from the one on the roof of their classroom.

There are currently more than 25 million mobile phones in use in the UK but this figure is expected to double as third-generation phones - which will offer video pictures and enhanced internet facilities - are introduced over the next few years.

Simon Mann, one of the authors of the NRPB study, said: "There has been huge public concern over exposure to radio waves from base stations, and there was a real need for someone to produce some independent data that could be held up for everyone to see.

"We chose places to investigate where people were concerned about masts but in all of them we found the levels of radiation were well within guidelines and not hazardous."

'More research needed'

Early results of the study were passed to the Independent Expert Group on Mobile Phones, chaired by former government chief scientific adviser Sir William Stewart.

Last month Sir William's group published a report calling for stricter planning controls on masts.

But NRPB deputy director John Stather said more extensive research was needed.

He called for a systematic study that would examine thousands of locations across the UK, and supported the Stewart report's recommendation that a database of all mobile phone bases should be established.

In September the Department of Health is expected to announce details of a UK-funded study examining the effects of mobile phone radiation on health, he added.