Hundreds of US air passengers have lodged complaints over use of full-body security scanners in the past year, charging they violate personal privacy and may be harmful to their health, documents released on Tuesday showed.
The United States began testing the devices in a pilot programme after the September 11, 2001, attacks, but the pace of use has increased since a passenger with a bomb hidden in his underwear tried to blow up a US airliner on Christmas Day.
The scanners, 44 of which are in use at 21 airports, are aimed at detecting explosives or other potentially dangerous items hidden on travellers, but they can produce detailed images of the body. Operators currently work in a separate room and view images that blur the face and genitalia.
The Transportation Security Administration, releasing the documents after a Freedom of Information Act request by the Electronic Privacy Information Center, said air travellers lodged more than 600 complaints over use of the machines in the past year.
The complaints ranged from concern about genitals being seen and the use of the devices on children, to anger over passengers not being told they could request a pat-down search instead and potential health worries from the scans.
"I was not given an option to use the whole body screening device. Neither was anyone else. It appeared that everyone was being required to go through the devices, even children," said one complaint from an unidentified traveller who flew through Tulsa airport in May 2009.
The TSA downplayed the complaints, saying only 600 of more than 4 million air travellers had lodged objections — an "infinitesimally small" 0.015 percent — and stressing that passengers could opt for an alternative form of screening.
"TSA takes passenger questions and concerns seriously and has multiple methods of receiving feedback from the travelling public," the agency said in a statement.
Polling shows most air travellers — nearly 80 percent — approve of the use of advanced imaging technology to screen airline passengers.
Complaints about the scanners flooded in after the bombing attempt in December. The surge may have been a part of a call-in campaign as many were received by the TSA's call centre on January 15.
TSA and the Department of Homeland Security have defended the use of the machines, saying that the images are not stored and screeners examining the images are in a separate location and cannot see the passenger.
TSA plans to have about 450 full-body scanners deployed by the end of the year. Some of the machines use 40 millimetre wave technology and others use backscatter, low-level X-rays, though officials have said the health effects were minimal.