Full Body Scanners Safe for Air Travelers, Experts Say
< Jan. 13, 2010 > -- U.S. security officials plan to use more full body scans at airports following an aborted terrorist attack on an airline flight in December. Experts say this increased scanning -- aimed at detecting explosives and weapons -- won't expose passengers to excess radiation.
There are two types of scanners currently used in the U.S. Millimeter wave scanners, which use radio waves, don't expose passengers to any X-rays. While no adverse health effects have been shown from these scanners, not much research has been done on their use.
The other scanner type, backscatter scanners, use very low levels of X-rays, but are also considered safe by nuclear medicine experts. "A passenger would need to be scanned using a backscatter scanner, from both the front and the back, about 200,000 times to receive the amount of radiation equal to one typical CT scan," explains Andrew J. Einstein, M.D., director of cardiac computed tomography (CT) research at Columbia University Medical Center in New York City. "If you were scanned with a backscatter scanner every day of your life, you would still only receive a tenth of the dose of a typical CT scan."
Radiation Minimal, Safe During Pregnancy
The amount of radiation from a backscatter scanner equals about 10 minutes of the normal amount of radiation constantly present in the environment in the U.S., Dr. Einstein says. "I believe that the general public has nothing to worry about in terms of the radiation from airline scanning."
Full body scans are also safe for pregnant women. No studies have shown an increased chance of miscarriage or birth defects from these scanners, according to Dr. Einstein.
"A pregnant woman will receive much more radiation from cosmic rays she is exposed to while flying than from passing through a scanner in the airport," adds Dr. Einstein.
Cell Phones Emit More Energy Than Scanners Do
Millimeter wave scanners produce 10,000 times less energy than a cell phone, according to the U.S. Transportation Safety Administration (TSA). "We, and all objects around us, generate millimeter wave energy, and we are exposed to it every single day," the agency's Web site states.
But because health effects of the more common millimeter wave scanners are relatively unknown, at least one expert believes a safety study is warranted.
"I am very interested in performing a National Council on Radiation Protection and Measurements study on the use of millimeter wave security screening systems," says Thomas S. Tenforde, the council's president.
"I think it would be helpful to convene an expert panel to prepare a concise summary of the health and safety issues associated with the use of this type of security screening system," he adds.
Backscatter body scanners aren't currently used at U.S. airports. But the TSA plans to purchase several hundred by the end of 2010. In addition, 40 millimeter wave scanners are now in use at 19 national airports.
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What to Expect When Flying
Planning air travel? Here's what you need to know about full body scanning: You'll get plenty of advance notice if the technology is being used. Informational signs, including sample images, are prominently displayed at security checkpoints in front of the scanners.
Scanning requires passengers to walk into an imaging portal. Inside, you'll need to stand in different positions and remain still for a few moments during the procedure.
Full body scanning is always optional. If you refuse the full body scan, you'll be screened an alternate way and patted down by a TSA agent.
Passengers with joint replacements or other medical devices that regularly set off metal detectors during conventional screening may prefer full body scanning because it's quicker and less invasive than a pat-down.
The scanner does not store, print, transmit or save your image, and it blurs facial features. Images are automatically deleted after they are reviewed by a remotely located security officer.
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