- Scanners use X-ray technology to show up hidden explosives or weapons
- Fears machines could emit harmful levels of cancer-causing radiation
- European report said risk 'close to zero' but bosses still failed to give go-ahead
Experts feared the 'naked' body scanners, which use X-ray technology to show up hidden explosives or weapons, could emit harmful levels of cancer-causing radiation.
New trials of the device, which display a 'naked' image of the person being scanned - were blocked by the European Commission last November.
But Manchester Airport, the only airport in Europe using the £80,000 machines, was told it could continue using them for another year.
Now, after the machines have come to the end of their three year trial, European Commission chiefs have failed to give their approval for their full time use.
EC bosses eventually declared the risk was 'close to zero' in a report in May - and Manchester airport expected the technology would be approved for permanent use.
But bosses are still waiting for the green light and now say they have been left with no option but to axe the 16 security machines because Brussels legislation does not allow security trials to exceed a three-year period.
As Manchester airport introduced the scanners as part of a security pilot in October 2009, they will have to scrap the machines at the end of next month.
In a red-tape wrangle, £1.1m will be splashed out on new 'privacy-friendly' machines and the recruitment of an extra 55 full-time security officers, who will manually frisk passengers.
The new scanners will use radio-frequency technology instead of X-ray radiation.
Russell Craig, spokesman for the airport, said: 'We've been talking to passengers literally every week and our security staff and overwhelmingly in August it was 100% thumbs-up to security at Manchester Airport.
'We've had visits from airport and governments from all over the world to see how we do it.'
'Today, we're just kind of standing around scratching our heads wondering why a trial that was popular with everybody, that everybody approved of, just never got the green light from Europe.'
The report from the EC's Committee in May said radiation doses were 'very low' compared with other sources such as cosmic radiation received during flights.
But it did add that the long-term effects, such as cancer risks, could not be 'entirely excluded'.
American academic Dr David Brenner said he believed the scanner could deliver up to 20 times more radiation to the skin than previously thought - potentially increasing the risk of skin cancer.
Fears were also raised that the scanners were an invasion of privacy and some passengers and religious groups had questioned their use.
The scanners were introduced at Manchester airport in a security crackdown after incidents such as the attempted 'underwear bomb' terror plot in 2009.
Passengers selected for scanning have, in the past, been banned from flying if they refuse to pass through the device.
The airport said around 10 passengers were unable to board their flight after refusing to pass through the scanners, known as 'back scatter' machines.
They were used at Heathrow but scrapped amid complaints about invasion of privacy. They have also been tested in Germany, France, Italy, Finland and Holland.
Research has suggested that, despite the low radiation dosage, that because of the large number of scanners in the U.S., hundreds of passengers a year could get cancer.
When there were 250 scanners in the U.S. last year, research suggested up to 100 passengers a year could get cancer.
Earlier this year it was reported that more than 600 Advanced Imaging Technology units, using X-ray technology, have been installed at 140 airports across the U.S.
The first X-ray body scanner was developed in 1992 by Steven W Smith. He sold the technology and rights to Rapiscan Systems, which now manufactures and distributes the device.
Fears about the health risks were raised in the U.S. as far back as 1998 when the machine known as the Secure 1000 was evaluated by a panel of radiation safety experts brought together by the Food and Drug Administration.
They all expressed concerns about the machine because it violated a longstanding principle that humans should not be X-rayed unless there is a medical purpose.
The machine's inventor told panelists that the machine would most probably not be widely used for many years to come.
Schiphol Airport in Amsterdam was the first airport to implement the scanners in 2007.
In the U.S. the Transportation Security Administration scanners sparked a heated debate over security concerns versus travelers' privacy when they were first brought in in autumn 2010.
The machines have also been installed in some courtrooms.
In response, New Jersey's legislature issued a resolution urging Congress to review the programme.
Study group Electronic Privacy Information Center then filed a lawsuit to suspend the use of scanners at U.S. airports pending an independent review.
In February 2011, a trial of new 'non-intrusive' body scanners started at Atlanta, Las Vegas, and Washington, D.C. before they were rolled out permanently in July last yer.
New York's Newark Liberty International airport followed in September last year, where more than eight million passengers boarded planes in 2010.