The Truth About TSA Scanners

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To most of us, TSA airport body scanners are a hassle at their worst and embarrassing at best, especially at major airports where lines only seem to be getting longer. But the question of whether they pose a real health concern for radiation risk still remains a little ambiguous in 2015 – years after the first controversial machines were introduced.
 
The short answer is no: Airport scanners are about as harmful as nuking food in your apartment microwave – if not less so, according to radiology physicists who work with much more advanced machines. "[TSA scanners] offer no greater harm than simple things we do in life," Andrew Maidment, Chief of Radiological Physics at the University of Pennsylvania, says. "The drive to and from the airport will be much more likely to result in death than the x-ray scanner. But x-rays are very much an unknown for people, so the risk is harder to dispel." But it still helps to know why health concerns were raised in the first place.

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Airports have typically used three types of safety scanners: metal detectors, millimeter wave scanners, and something called x-ray backscatters. It's these backscatters that got the bad press years ago, says John M. Boone, a radiology professor at the University of California Davis, because people were worried about privacy issues (like revealing private parts), and also the thought of x-rays being emitted by the machine. (X-rays might break DNA strands – which is one of first the steps a cell takes towards cancer, David Brenner, a radiology physicist at Columbia University's Medical Center, says.)
 
So in 2013, the TSA eliminated backscatters altogether, but because of the privacy concerns, not the health risks. "In truth, all three technologies are very safe for passengers," says Boone. And even when they were still in use years ago, backscatter x-ray scanners showed only minimal radiation exposure. When the American Association of Physicists in Medicine measured the x-ray exposure from a scanner, it was equivalent to about 17 seconds of a typical airplane flight – not much at all, explains Dr. Bruce Libby, a radiological physics professor at the University of Virginia. In fact, the dose was so low that it's equivalent to background radiation we get in everyday scenarios.

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You can get minimal radiation from living in a concrete apartment building or working at a concrete office building (because of the decay of uranium and other elements), having a basement apartment (because of the radon), living at higher elevations (i.e. the Rockies, where cosmic and background radiation could get to you), or taking a flight from New York to L.A. (again, cosmic radiation). "All of these increase your radiation exposure many times more than the airport scanners," Maidment says. But that doesn't mean we should avoid any of those scenarios.
 
As for the millimeter wave scanners, the machines use radio frequency waves and don't emit enough energy to break DNA (they emit as much as a cell phone). And when it comes to metal detectors, Boone says people with implanted medical devices like pacemakers or neuro-stimulators should simply talk to their doctor about opting for pat downs and avoiding metal detectors, whose magnetic field could tug on the tools and cause problems. Most radiologists agree: More things in the course of your travel are more likely to kill you. "Tainted food in the plane, passengers coughing next to you," Maidment says. "Driving a car, smoking a cigarette, having a cocktail, skiing, eating too much, not washing your hands after being in a public place – life is a risky enterprise, but you should not worry about the airport scanners."