The Police Federation is ready to drop support for the new £2.5bn Airwave police radio network after independent research gave its backing to health concerns over radiation emissions.

The officers' union has issued an ultimatum to the Home Office to give satisfactory reasons for its contention that the radios are safe.

"Big money is at stake, but we believe the health of police officers is of paramount importance," said a Police Federation spokeswoman. She confirmed that the union was serious about pulling the plug on Airwave, but added it was uncertain how this would affect the contract with network operator BT.

The health fears centre around whether Airwave emits pulse radiation. The network uses terrestrial trunked radio (Tetra) technology to broadcast 17.6 waves per second.

Independent researcher Barry Trower said this pulsation frequency was dangerously similar to the frequency of human beta brainwaves. He believes this can cause serious illnesses, including heart and blood ailments, bone marrow problems and tumours.

Liberal Democrat MP Richard Allan said he would consider raising the matter in Parliament this week. It would not be the first time that Airwave has been debated.

"It would be a shame if radios that are necessary for operational reasons could not be used for health reasons," Allan said. "It needs a bigger debate, involving concerns about mobile phones as well. Everything carries a risk, which must be weighed against its benefits. At the moment we don't have a way of judging the risk."

Allan added that forces had to ensure the equipment they provided was safe, and that Tetra radios had been issued on the advice of the Police Information Technology Organisation (Pito). "Police forces may want to take action against Pito if it was wrong," he said.

BT has denied that Airwave emits pulsing radiation. Research by the National Radiological Protection Board goes even further and states that Tetra networks never pulse.

But Alasdair Philips, director at emission research company Powerwatch, has tested Tetra-based Dolphin radios and said they "definitely pulse". He asked BT if he could test its Airwave network and was recently given permission to do so in mid-December.

Philips finds it incredible that the European Tetra standard was adopted without sufficient research into its effects on humans. Another problem, he said, was that radiation affected the brain long after the radio had been switched off.

"We are 10 years on and no work has been done on the effects on humans," he said. "This will be the first time people use a radio that pulses with human frequency next to their brain."

In the meantime, BT is pressing on with rolling out Airwave. Since the health concerns emerged, civil action groups have successfully obstructed planning permission for base station masts. And two local councils have taken BT to court for building masts without obtaining permission.

Since meeting local opposition, BT has started to organise local meetings before councils decide on planning permission for masts. The meetings aim to inform people of the benefits of Tetra and to reassure them of its safety.In a statement given to Network News, a BT Airwave spokeswoman said, "We haven't been notified of any plans by anybody to withdraw co-operation from the Airwave service. It is worth remembering that by enabling more effective communications the service will enhance the safety of our communities and individual police officers."

How safe is Tetra? The questions the Home Office must answer

How much (and what type of) radiation does the handset emit?

What experiments have been done to measure how officers inside a vehicle are insulated from the transmitting device?

Why is a pulsed frequency of 17.6Hz used when it is known to interfere with the brain's beta rhythm and was warned against by the Stewart Committee?

The NRPB report recommended an epidemiological study be carried out on the use of Tetra. Shouldn't police officers be asked their permission if they are to take part in what is a long-term medical study which may result in a number of brain tumours, spine tumours, eye cancers, heart disorders and many other illnesses?

As further research is needed, should this not be done before Tetra becomes national, and can the results be made available to the Police Federation for scrutiny?