Ever since the “Panty-Bomber” strolled past security and tried to bomb a Northwest flight last year, we been bombarded by people characterizing the “full body scanner,” as a high-tech security savior able to discover any hidden weapon and explosive quickly and safely.
Could that be true?
TSA announced they will install 150 millimeter wave (MMW) full body scanners this year, and order 300 more. TSA also announced they intend to install 150 Backscatter full-body scanners.
Does this make sense?
Like everyone, I want to be safe while flying, but I recognize that no security system is, or will be, foolproof, so flying will never be 100 percent safe and secure. What I want from my government is the most effective security “bang” for my tax dollars and fees.
Backscatter x-ray technology, unlike traditional x-rays which use the transmission of x-rays through objects, detects radiation which reflects from objects to form its image.
Millimeter wave (MMW) scanners use extremely high frequency radio beams transmitted from two simultaneously rotating antennas. The wave radiation reflected back from the body or other objects is used to construct a 3D image.
There are four issues to consider about these full body scanners; efficacy, privacy, safety, and bang for the taxpayer buck.
Efficacy:
The two most important aspects to understand about both the Backscatter x-ray, and the MMW scanners is that their scans don’t penetrate the skin, and they create images for inspection which depend on the density of what they are scanning.
If a terrorist hides a small bomb, gun or knife under their clothing, the scanners can detect them. If a terrorist hides an explosive material such as PETN, in low density power form in clothing (like the Panty-Bomber), it’s highly unlikely the scanners will detect it, as its density is too low.
According to Ben Wallace, now a member of the British Parliament who advised defense contractor Qinetiq, in their tests of the MMW scanners, the tests showed they pick up metal and other dense materials, but like passengers’ clothing, not low density materials such as powder, liquid or thin plastic.
If a terrorist hides an explosive such as a small stick of C4 wrapped in a plastic sheet in a body cavity, the scanners will not detect it, as they can’t penetrate skin.
It seems to me, that a determined terrorist can get their explosive or other “weapon” past full body scanners. When it comes down to it, as far as I’m concerned, quality pat-downs, explosive sniffing dogs, and better trained TSA agents would have higher odds of detecting the next “panty-bomber” than full body scanners.
Privacy:
My colleague, Edward Hasbrouck, in his article at Consumer Traveler, TSA’s nose grows as they explain whole-body scanners, wrote about these scanners’ privacy issues at length.
We now know, despite TSA assurances otherwise, airport body scanners can store, print, and transmit passengers’ scanned images. Moreover, we know that TSA’s exemplar scanner images are inaccurate and misleading. The actual images reviewed by TSA agents are full-screen, not thumbnails, high resolution, and zoomable on the TSA displays.
Every privacy concern articulated by opponents of these scanners is apparently real, and rather than address them, TSA has apparently attempted to cover them up.
Safety:
The effects of x-rays on the human body are well known and have been studied for years. American Science and Engineering Inc. reports that a person undergoing a backscatter scan receives approximately 0.01mrems. According to U.S. regulatory agencies, 1mrem per year is a negligible dose, and 25mrem per year is the upper limit of safe radiation exposure.
Manufacturers of MMW scanners, such as L3, state the scanners “offer advanced imaging—without any health risks.” While apparently no long term studies of the effect of MMW radiation on humans has ever been made, I did find a study by Boian S. Alexandrov (and colleagues) at the Center for Nonlinear Studies at Los Alamos National Laboratory. It showed the scanners’ terahertz waves could “…unzip double-stranded DNA, creating bubbles in the double strand that could significantly interfere with processes such as gene expression and DNA replication.” That is serious if accurate.
I’m not a doctor, but I’ve read enough to know that exposure to x-ray is cumulative. On the surface, backscatter x-ray seems safe for the occasional traveler, but personally, I’m not so sure about frequent fliers, especially ones who have had significant x-rays for medical purposes. When it comes to MMW scanners, there is enough evidence to say to me, before we deploy any more of them, long term health and safety studies need to be performed.
NOTE: People with medical implants such as pace-makers should avoid electromagnetic pulse generating body scanners as they can significantly alter the waveform of the pacemaker pulse.
Bang for the buck:
It has been reported that these scanners would cost as much as $200K apiece, plus installation and infrastructure. That adds up to more than $120M just for TSA’s 450 new MMW scanners and 150 new Backscatter scanners. I’d rather spend that on upgrading our TSA agents so they can use psychological profiling.
No matter how many technological marvels are on hand at US airports, they don’t mean a thing unless they’re used on the right people.
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