LANCASHIRE Police have asked the Government for further tests on the safety of controversial radio system Airwave, after officers raised concerns over health issues.

Airwave is still plagued with problems despite being given the green light more than five months ago.

Some officers say they are worried about the amount of heat produced by the radio sets when held to the ear and also by a national police federation report which said the Government was using officers to pilot the system as "guinea pigs in a cancer trial."

Director of Corporate Services at Lancashire Constabulary David Brindle, said he had written to the Home Office suggesting monitoring a group of officers using Airwave so they could look at the effects.

And Chairman of the Lancashire Police Federation Steve Edwards said the issue was a national one which would affect officers from forces across the country.

Mr Edwards said there were still concerns about the system's coverage and some design flaws.

In addition to the heat problem, one of the most serious safety concerns is the so-called 'spiking,' a high-pitched screech emitted over the radios mainly heard by operations in police communication rooms.

The noise is now so bad that union bosses say they are keeping a record of spiking incidents which may be referred to the Health and Safety Executive.

Lancashire Federation Chairman Steve Edwards said: "The problem does appear to be getting more prevalent and we are extremely concerned that it could cause damage to the hearing of officers and civilian support staff."

Other ongoing problems with Airwave include poor ground to air communication, and interference with electronic equipment.

Officers have been forced to go back to using old fashioned breathalyser equipment known as "bag and tube" as airwave interferes with modern systems.

Tests have also shown that airwave may affect the speed enforcement systems used by motorway police and the Automated Number Plate Recognition system -- Lancashire Police's much heralded new tool in the fight against motorway crime and travelling criminals introduced earlier this year.

The Airwave system was also supposed to operate between different police forces, but this will now not be possible until at least 2004, police bosses have been told.

Greater Manchester Police have already abandoned Airwave and gone back to their old analogue radio system because they encountered so many problems.

Claimed benefits of Airwave include a background noise filter and, for the first time, encryption, which means that criminals cannot listen in.

In the future, automatic vehicle and person location will ensure that control rooms are aware of every officer's whereabouts and emergency buttons will allow officers to call for backup. Eventually, officers should be able to access to local and national databases including the Police National Computer.

More than a million coverage checks were done throughout Lancashire during the pilot tests for the project, which began in March last year.

Concerns were raised about the safety of the digital TETRA devices because of the possible radiation risk and the chance that they could interfere with vital electronic equipment, such as hospital machines.

Lancashire Fire and Rescue Service became the first brigade in the country to use the Airwave digital radio system when it switched over from the analogue system last week.

Dave Thompson, radio replacement project manager for the service, said: "Airwave puts us truly in the realm of the 21st century technology."