Body Scanners – A Revealing Issue

16 February 2011 (Last Updated February 16th, 2011 18:30)

Despite largely negative public opinion the use of body scanners in airports has taken off. Frances Cook catches up with a flurry of recent safety and privacy issues concerning technology and asks are we safer?

Body Scanners – A Revealing Issue

Although Schiphol Airport was the first major airport to use body scanning technology in 2007, it was the year of 2010 that saw body scanners really impact airports - and the public - worldwide. The technology was given the go ahead for deployment in UK airports at the start of the year, and by November 2010, the Transportation Security Administration (TSA) announced its 200th advanced imaging technology (AIT) unit in the US - and there are to date in the States, 486 advanced imaging technology machines located at 78 airports. Australia, Canada and India also started to implement the technology at major airports.

Types of imaging technology

Backscatter imaging technology and millimeter wave technology are competing technologies used to create body scanning equipment that detects forbidden items at airport security check points. The backscatter imaging technology (ionising) works by projecting an x-ray beam over a surface at high speed, producing a reflection or 'backscatter' which is then displayed on a monitor. Millimeter wave technology (non-ionising) bounces electromagnetic waves off the body to create a black and white image, which is then pored over by safety experts to assess a passenger's security threat.

European safety response

Following the attempted attack on Northwest airlines flight 253 to Detroit on Christmas Day 2009, a review of aviation security measures in the UK were carried out. These included "an increase in the use of explosive trace detection", plans for greater "random searching of passengers" and the introduction of AIT. In February 2010 security scanners were deployed to Heathrow and Manchester Airports, and further scanners deployed in the following months. Health risk concerns were relieved through independent trials and through the DfT's own assessment - although it was highlighted that the "urgency" of the roll out meant the government "would have liked to have consulted fully before producing this interim code and before introducing security scanners".

In response to safety concerns over the use of AIT, the UK's Health Protection Agency (HPA) stated that the radiation dose from backscatter scanners is equivalent to the level that "an air passenger flying at 35,000ft receives in about 1 minute". The Department for Transport confirmed that both ionising and non-ionising radiation technologies did not pose a safety threat. "All the technologies deployed have been assessed by government health and safety regulators," states the DfT. "The dose received from being scanned is far below the allowed levels in the UK and does not constitute an unacceptable risk to health."

"As widespread implementation occurred, public concern over the safety of the technology grew."

US safety concerns

As widespread implementation occurred, public concern over the safety of the technology grew. The TSA addressed these concerns, stating that in the case of backscatter technology "each full body scan produces less than 10 microREM of emission, the equivalent to the exposure each person receives in about 2 minutes of airplane flight at altitude". And it stated for millimeter wave technology that, "the energy emitted by millimeter wave technology is thousands of times less than what is permitted for a cell phone".

In October 2010 the FDA issued a letter to the University of California, which questioned whether the "safety of the security devices had been adequately demonstrated". Deputy Director for Technical and Radiological Initiatives, John L McCrohan, confirmed that AIT meets the standard set for general use systems and that independent safety data does exist - for example Johns Hopkins University Applied Physics Laboratory carried out an assessment for TSA in October 2009. "In summary the potential health risks from a full-body screening with a general-use x-ray security system are miniscule," concluded McCrohan.

Passenger privacy concerns

Public opinion over the efficacy of security seemed inconclusive in 2010. While an MSNBC poll of 8,500 readers showed that around 85% didn't think the technology would increase travel safety, a CBS telephone poll showed approximately 80% approved.

Disciplinary action for a Heathrow worker in March 2010 didn't help fears that images from body scanners could be misused subside - in this particular case an employee of Terminal 5 was found staring at the scanner image of a female colleague.

"Public opinion over the efficacy of security seemed inconclusive in 2010."

On the grounds that it, amongst other issues, infringes upon the Privacy Act, in 2010 the Electronic Privacy Information Centre (EPIC) filed a lawsuit to suspend the use of body scanners at US airports. In January 2011 it filed its reply brief claiming: "the TSA has acted outside of its regulatory authority and with profound disregard for the statutory and constitutional rights of air travellers". The District of Columbia Circuit Court of Appeals will hear the case in March 2011.

Secretary of Homeland Security Janet Napolitano wrote a piece in USA Today reassuring the public that "AIT machines are safe, efficient, and protect passenger privacy" and claimed that "the vast majority of travellers say they prefer this technology to alternative screening measures. However, the American Civil Liberties Union called the machines an "invasion of privacy".

Despite the controversy the TSA stands firm in its belief that AIT "cannot store, print, transmit or save the image, and the image is automatically deleted from the system after it is cleared by the remotely located security officer". It also points out the difference between each technology regarding privacy. "To further protect passenger privacy, millimeter wave technology blurs all facial features and backscatter technology has an algorithm applied to the entire image." It also confirms that passengers can opt out of the screening and in its place will receive an "alternative screening" including a "physical pat-down".

Scanners are security staple

The deployment of both backscatter and millimeter wave scanners has been quicker than expected over the last twelve months causing much concern and controversy over health and safety issues as well as privacy. The reason for their implementation, however, is to prevent terrorist attacks and the urgency surrounding roll out is considered to be appropriate to the level of threat presented to aviation - and the general public. "The use of security scanners is both a legal and proportionate response to a very real terrorist threat," says the UK's DfT confirming its belief that body scanners are now nothing less than a necessity for aviation security.