Airport whole body scanners have been in use for over a year in both the U.S and Canada, but they are being debated once more this holiday season during the annual travel blitz. Airport scanners or ‘advanced imaging technology (AIT)’ units have been rolled out across airports in North America and Europe. In the United States, 464 AIT units now operate in 75 airports across the country. While in Canada, 44 units operate at all of the country’s major airports. These machines have been widely debated on both sides of the border for their effectiveness, infringement on privacy, and health risks. The machines are here to stay, but are the criticisms valid?

The debate over airport scanners has long focused on the possible health risks associated with the machines. It is important to remember that not all airport scanners use the same technology. In fact, there are two main competing types of technology used in full body scanners. Backscatter X-ray units use low-doses of x-rays that bounce off the skin. The images are chalky and filters can be applied to hide faces. The TSA has argued that the health risks of these units are minimal as travellers are only exposed to as much radiation as would be received during 2 minutes of normal flight at altitude or about 0.03mSv of radiation. Other experts disagree: On April 26th, 2010, four University of California professors wrote a letter expressing their concern over backscatter X-ray technology. They argue that though the overall dose of X-ray energy is low, it is absorbed by the skin at possibly damaging levels. They argue that no independent safety data exists and more research needs to be done on low radiation exposure. About half of all airport scanners in the United States currently use this technology and are provided by American Science & Engineering (AS&E). AS&E CEO Anthony Fabiano has claimed the technology provides a superior level of detection when compared to existing technology and dismisses health concerns. The machines can be expected to be a part of the U.S security apparatus for the near future as large million dollar orders are being made for both airport scanners and mobile backscatter units for use at borders and checkpoints. By the end of 2011, 1000 X-ray machines will be in use in the United States, representing about half of the nation’s 2000 lanes of security checkpoints. These machines are currently not in use in Canada.

Millimeter wave scanners represent the main alternative to backscatter X-ray technology. They represent half of all airport scanners in the U.S and are the only technology currently in use in Canada. Millimeter wave scanners use extremely high frequency radio waves to produce images. This technology does not use radiation like X-ray units. The image quality resembles a negative and the TSA has claimed they scanners produce 10,000 times less energy than a cellphone call. With orders in the hundreds of millions of dollars from both the United States and Canada, the millimeter wave scanners produced by L3 Communications continue to be big business.

The effectiveness of airport scanners has recently been called into question, with experts claiming the technology can miss key threats. The TSA claims the technology has been effective in finding contraband that until recently may have been missed: items like small amounts of marijuana wrapped in plastic or ceramic knives stitched into the linings of clothes. However, experts believe the technology is ineffective in identifying explosives. Explosives like pentaerythritol tetranitrate or PETN are odourless and easily moulded into shapes that can fool scanners. Former inspector general for the Department of Homeland Security Clark Ervin said, “It’s not an explosives detector, it’s an anomaly detector.” The results of studies conducted by the U.S government at the federal Transportation Security Laboratory in New Jersey are mostly classified, but a few findings were released. The main findings of the report indicated that the effectiveness of the scanners in detecting weapons and contraband varied by those evaluating the images. The study found backscatter X-rays can be obscured by parts of the body and these scanners may not pick up thin items seen “edge on”. Furthermore, objects hidden inside body cavities could be missed by both types of technology.

Perhaps the most vociferous debate over whole body scanning technology has centered on the privacy concerns associated with the images the machines produce. In fact, before the Christmas Day bomber attempted to blow-up a jet liner at the end of 2009, roll out of the technology was continuing slowly in America and limited to test runs in Europe. In the wake of the failed attack, the technology’s adoption was accelerated around the world. However, opponents of the scanners have never wavered in their belief that the scanners represent a dangerous infringement on freedom and privacy. Millimeter wave units have been criticized for the technology’s ability to see through clothes and reveal breast implants, colostomy bags, and body piercings. Furthermore, the promise that the images would not be stored and the files dealt with responsibly is one many find hard to swallow. The fact that during TSA training sessions for the scanners, TSA worker Rolando Negrin was ridiculed by colleagues for the size of his manhood did nothing to assuage public fears. Despite such fears, acceptance of whole body scanners seems to be widespread. TSA spokesmen have claimed 99% of travellers opt for a full body scanner rather than a pat down. Surveys performed in Canada have claimed 96% of Canadians prefer the machines to a body pat down as well. In a world where increasingly nothing is private, many may simply prefer the relative modesty of standing inside a scanner than submit to a clumsy and awkward pat down.

Whole body scanners may have been controversial from their inception, but in the wake of attempted terrorist attacks like the Christmas Day bomber, their opponents have been washed away by a tide of worry over security concerning air travel. With the health risks of the machines either non-existent or requiring years of scientific study for any kind of proof, the machines have been rolled out across the world with surprising speed. However, their adoption may have been too fast for a thorough assessment of their effectiveness in detecting contraband and explosives. The scanner’s effectiveness is dependent on the training and intelligence of the officer’s responsible for viewing the images and except for some minor successes, the TSA cannot provide solid evidence of the technology’s reliability. With future orders for both backscatter x-ray and millimeter wave units already placed, it seems governments around the world believe in the technology and for better or worse they are here to stay.