To Scan or Not to Scan?

TSA deploys hundreds of backscatter imaging units nationwide

• By Megan Weadock
• Jun 01, 2010

In March, the Transportation Security Administration began deploying 150 backscatter imaging technology units, which were purchased with American Recovery and Reinvestment Act funds, in airports across the country. By the end of the year, TSA plans to deploy about 450 of the imaging technology units.

The advanced walk-through imaging technology is designed to detect both metallic and non-metallic threats, including weapons and explosives, that a passenger is carrying on his or her person, without necessitating physical contact.

Anyone who has seen the backscatter technology images will agree that it must be effective at detecting any number of threats. (After all, there’s really nowhere to hide anything in those photos.) But at a time when airport security is presumably at its strictest -- and queues are longer than ever -- the flying public has to wonder how the new imaging technology will affect them.

Privacy and Safety Concerns
When I initially learned about backscatter technology, I was concerned about the images it produces: black and white, gritty and, more than anything, naked.

Of course, blurring algorithms are used to ensure anonymity and offer some degree of modesty.

Also, the images are viewed by a TSA officer in a remote, secure location, and the officer assisting the passenger never sees them. The technology ensures the images can never be saved, printed or transmitted, and each remote officer is forbidden to take photo-enabled devices into the resolution room.

Once the image is inspected, it is cleared from the system immediately.

Of course, screening by advanced imaging technology is optional for all passengers. So if I get pulled out of the security line, I can either opt for a physical pat-down or walk through the backscatter imaging portal. TSA requires there to be sample images displayed at security checkpoints so passengers know what they’re getting into. Not surprisingly, the department reports that 98 percent of passengers who give advanced imaging technology a try prefer it over other screening options.

As for the technology’s safety features, TSA has gone to great lengths to ensure that the new screening techniques have almost no effect on the human body.

But as someone who avoids unnecessary sun exposure and wears SPF 15 year-round, I wondered what sort of radiation levels this kind of advanced imaging technology gives off. After all, the technology works by projecting X-ray beams over the body to create a reflected image.

Not to worry, TSA says. Advanced imaging technology meets national health and safety standards and has been evaluated by the FDA, National Institute for Science and Technology, and Johns Hopkins University, among others. The results showed that the radiation doses for passengers being screened -- as well as operators and bystanders -- were well below the dose limits specified by the American National Standards Institute.

To put that in perspective, consider that a single backscatter technology scan exposes a person to the same amount of radiation as they encounter flying on an airplane for two minutes. (For someone like me, who takes fewer than 10 roundtrip flights a year, that seems reasonable. But I wouldn’t want to be the TSA employee operating the device for eight hours a day.)

Hurry Up and Wait?
On a recent trip to California, I spent an unprecedented 75 minutes waiting in the security line at Dallas- Fort Worth International. It made me wonder if wait times will get even worse with the addition of backscatter imaging units across the country.

According to TSA, the imaging process is simple and, luckily, fairly quick. Passengers who choose an image scan over a physical pat-down will walk into the imaging portal. Once inside, they will be asked to stand in different positions and remain still for a few moments while the technology creates their image in real time. The remote TSA employee inspects the images, while communicating with the agent running the backscatter scanner via headset. Once the remote agent gives the OK, the passengers can exit the opposite side of the portal.

All things considered, this sounds potentially faster than a physical pat-down, and the process allows other passengers to continue moving through the queue.

Prior to the big March deployment, there were only eight backscatter units in use in five major U.S. airports. The similar millimeter wave scanners, which use harmless electromagnetic waves to create a 3-D image of each passenger, are more prevalent.

All told, more than 20 U.S. airports use advanced imaging technologies. But by the end of the year, backscatter technology will be everywhere. For the sake of argument, I might have to try it the next time I get pulled aside at DFW Airport.