A few days ago I reported that the TSA will be removing Rapiscan full body scanners from airports around the country because (contrary to the story the TSA had been putting out) the images from the scanners were too realistic.
Of course, that wasn't the only concern passengers had regarding the scanners. Safety issues had been raised. People were concerned over the level of exposure to x-rays, especially for frequent flyers and young children.
The TSA has consistently asserted: Advanced imaging technology screening is safe for all passengers, including children, pregnant women, and individuals with medical implants
“Advanced imaging technology is safe and meets national health and safety standards. Backscatter technology was evaluated by the Food and Drug Administration’s (FDA) Center for Devices and Radiological Health (CDRH), the National Institute for Standards and Technology (NIST), and the Johns Hopkins University Applied Physics Laboratory (APL). All results confirmed that the radiation doses for the individuals being screened, operators, and bystanders were well below the dose limits specified by the American National Standards Institute (ANSI).” Source: www.tsa.gov/ait-safety
But public safety concerns were not quelled. As a result, the TSA announced in December, 2012 that it was working on a contract to be awarded to the National Academy of Sciences to further understand the effects of backscatter X-ray Advanced Imaging Technology.
Yes, there are two different forms of Advanced Imaging Technology in use
There is Millimeter Wave Technology and X-ray Backscatter Technology. The FDA has reported on the safety of both kinds. For X-ray their report states: General-use x-ray security screening systems deliver an extremely low dose of ionizing radiation to the person being screened. The radiation dose is so low that there is no need to limit the number of individuals screened or, in most cases, the number of screenings an individual can have in a year. Millimeter wave security screening systems use non-ionizing electromagnetic radiation. There are two types of millimeter wave security systems: active systems that expose the person being screened to small amounts of millimeter wave energy and passive systems that sense naturally occurring millimeter wave emissions from warm bodies.
The Millimeter wave technology is generally considered safer. In fact, the TSA may tacit agree since ProPublica.org’s Michael Grabell reported in October that “The Transportation Security Administration has been quietly removing its X-ray body scanners from major airports over the last few weeks and replacing them with machines that radiation experts believe are safer.”
Of course, the story put out for pubic consumption is that the TSA has made the decision not because of safety concerns but to “speed up checkpoints at busier airports.” (It is likely however that the x-ray machines will end up being used in smaller airports.)
In fact, concerns increased when it was reported that European airports won’t use the technology, judging it to be... unsafe. In November, 2011, Michael Grabell reported in ProPublica that Europe banned X-ray body scanners. Grabell noted: The European Commission, which enforces common policies of the EU's 27 member countries, adopted the rule “in order not to risk jeopardizing citizens’ health and safety.”
What Does Europe Use?
European countries will be allowed to use an alternative body scanner, on that relies on radio frequency waves, which have not been linked to cancer. The TSA has also deployed this technology, millimeter-wave scanners, in U.S. airports. But unlike Europe, TSA deploys both kinds.
How Can I Tell Which Machine I’m About to Enter?
The X-ray scanner, or backscatter, which looks like two large blue boxes, is used at major airports, including Los Angeles International Airport, John F. Kennedy in New York and Chicago's O’Hare. The millimeter-wave scanner, which looks like a round glass booth, is used in San Francisco, Atlanta and Dallas. It's also used in Albuquerque.
Why Doesn’t the US Just Use Millimeter-Wave Scanners?
Who knows. Probably economics and who has been awarded contracts and for how much money.