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
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
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
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
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
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
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
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.