Hardly any subject to do with security has raised so much public discussion and controversy in the past few years as the introduction of so-called ‚body scanners‘.

It is obviously in the interests of the agencies responsible for security at airports and other passenger transit locations worldwide to ensure good passenger flow while still maintaining as near 100 % security effectiveness as possible. Although some of these initial trials in Europe actually resulted in slower passenger processing, whole body scanners do promise to speed up the security procedure by removing the need for any hands-on frisking. This challenge has undoubtedly been made easier by the latest developments in total body screening devices.

Raise and Rays
While some countries have already wholeheartedly adopted these machines some years ago, in others operation is taking place under restricted trial but nevertheless real, everyday conditions to prove their effectiveness and reliability, and to identify areas that need regulation and/or improvement. Two different technologies are currently being used.

X-ray scanners provided by, amongst others, the American manufacturer Rapiscan uses a backscatter-technique. Although extremely low doses of radiation are used, they still provide reliable detection of organic and inorganic materials. The Ait84 manufactured by Tek84 uses dual-mode transmission and backscatter to provide dual images in one shot without using any additional dose versus a backscatter only system.
An alternate technology, first trialed in airports as long ago as 2002 by Qinetiq, is also available from Smiths Detection, L3 and others. It is now under evaluation and generates millimeter waves at RF (a frequency between that of infra-red light and microwaves). It is somewhat quicker in producing results - it takes less than 10 seconds to obtain a multidirectional view - resulting in a potential throughput of up to 400 people per hour. But although the scan time of millimeter wave systems with 3 seconds is significantly shorter than the 6 seconds needed for backscatter systems, it takes almost 15 additional seconds for persons to enter the scanner, pose (lift arms) and exit.

Hence the total time of a person in the scanner is about 20 seconds including scan for both technologies in an airport setting. This is three passengers per minute or about 200 per hour for both backscatter and millimeter wave. Again, extremely low transmission levels are sufficient to deliver clear images and are no danger to the human body.
There is also a passive version of this type of sensitive scanner, like the Gen2 provided by Brijot Imaging, that emits absolutely nothing but instead simply receives the natural radiation of waves shorter than 1 mm that are emitted by the human body. Smiths Detection also provide an explosives and narcotics detector based on ion mobility spectrometry that quickly analyzes minute particles of such substances that are carried on the person‘s hair and clothes. Again a walk-through system, it is capable of handling up to 6 people per minute.

EU Rules, OK?
The use of such total body scanners was the subject of discussion amongst a sub-committee of the European Parliament during November 2010. A few recommendations have already emerged from the talks that will help to make the way legally clear for uniform introduction and management of such systems throughout Europe. For example, there must be no danger to health, and both personal privacy and data privacy must be fully respected. The "Use of Body Scanners - 10 Questions and Answers" document issued in July 2010 by the EU Agency for Fundamental Rights has demonstrated that EU legislators must now pave a way through the legal, moral and political minefields before widespread introduction happens.

What‘s the procedure?
On the one-hand, security staff get a natural workout as they are constantly on the move, but any manual pat-down procedure is both time and labor-intensive, so eliminating this - or at least reducing the frequency - can only be beneficial. Depending upon the specific system, it is not always necessary to remove jackets and/or shoes. The traveler stands in the body scanner and raises their hands above their head for a few seconds. In some systems they also need to turn 90 degrees for full detection. The operator is given an image showing any suspect items such as liquids, powders, gels, ceramics as well as all standard solid and liquid explosives, weapons and narcotics. Even money will be highlighted on the operator‘s screen. The analyst then indicates where the passenger should be patted down. Although this aspect lies wholly within the judgment of the security service operating the machine, it may be prudent to have the analyst - the person viewing the screen - in a separate room away from the scanner itself so that no association can be made between the person being scanned and the displayed image. In this way, personal privacy is respected but scanning is still effective.