March 08, 2010, 4:02 PM — Full-body scanners were installed at Boston Logan International Airport on Friday (see video), a technology that some see as important in identifying terrorist threats but which others worry is an invasion of privacy.
The airport became one of the first 11 in the country to receive the so-called advanced imaging technology (AIT) units, purchased with money from the American Recovery and Reinvestment Act (ARRA).
"Imaging technology safely screens passengers for metallic and nonmetallic threats -- including weapons, explosives and other objects concealed under layers of clothing -- without physical contact, to help the TSA keep the traveling public safe," said Lee R. Kair, assistant administrator for security operations with the U.S. Transportation Security Administration, during a news conference at Logan Airport.
The units, which have drawn fire from privacy advocates for their somewhat-revealing body scans, use backscatter technology to project low-level X-ray beams over the body. Once passengers enter a unit, they stand with their feet shoulder-width apart and their arms raised. X-rays are bounced off the body, and the returning rays produce an image that is viewed by a TSA agent about 50 feet away in a sealed room. The image resembles a chalk etching. If screeners detect a threat or anomaly, they can radio for another agent to make a closer inspection.
Trying to quell privacy concerns, Kair said: "The officer attending to the passenger will not view the image. As an additional precaution, the officer viewing the image will be remotely located and the image won't be stored, transmitted or printed and will be deleted immediately once viewed." He added that the machines have "zero storage capability."
The scan and review of the image takes about 20 seconds, and Kair said the units should not slow the passenger screening process. In fact, more time is spent checking and X-raying carry-on baggage, he said.
Kair said the backscatter units are safe and that the radiation exposure is equivalent to what a passenger would experience in an aircraft for two minutes at 30,000 feet.
The TSA began piloting AIT units in February 2007.
While the scanners will be used as a primary screening method at Logan, passengers are not required to be scanned and can request a pat-down and metal detection instead. Kair said there had been a 98 percent acceptance rate for the units among passengers at trial locations.
Another type of AIT unit that is not being deployed in Boston uses "millimeter wave" technology and produces an image that resembles a fuzzy photo negative.