Amidst growing concerns over airport safety, in 2007 TSA implemented their first full body scanners, which use either millimeter wave technology or backscatter X-rays to develop images of individuals that look through clothing. The purpose of using these devices in airports is to detect any foreign objects or illegal substances that an individual may be carrying beneath their clothing. There has been some controversy over the implications of privacy violation, but a larger concern is the health problems that may be associated with the technology.
The millimeter wave technology used in some body scanners has little, if any, negative health effects on the human body. Scanners using this technology emit waves that are contained within the T-ray range of the wave spectrum, which causes certain materials, such as clothing, to appear translucent, and creates a three dimensional image of a subject’s body. Millimeter waves do not use radiation, and there is no evidence as of yet that suggests these waves cause or accelerate any form of cancer. There has been some speculation that the waves have an impact on a level of DNA strands, but this result has not been supported in any studies. The size and frequency of the waves used in these imaging scanners are generally considered insignificant to a person’s health, especially when compared to the possible health problems associated with cell phones, and the radiation passengers are exposed to by flying in airplanes themselves.
Other body scanners use backscatter X-ray technology, which detects any radiation that a given object or subject may emit during the scan. The resulting two-dimensional image gives the observer a clear view of any materials that may be hidden by the subject beneath their clothing using ionized radiation. This radiation may have a negative effect on subatomic particles, causing them to react unnaturally. Though this form of X-ray does not produce the same radioactive damage as traditional X-ray devices, there is still some concern over long-lasting effects they may cause, particularly for people who are frequent fliers.
Ionized radiation, in high amounts with repeated exposure, can cause some serious biological damage, and though body scanners using backscatter X-rays use the waves in very small amounts, there is no known minimum to ensure that the rays will not damage tissue. Because there are no long-term experiments dealing with ionized radiation, the lasting effects of even small amounts of this radiation are unknown. Critics of full body scanners argue that, because of the lack of research regarding the dangers of extended exposure to ionized X-rays, they should not yet be implemented.
Supporters of full body scanners argue that all people are constantly exposed to radiation, even without the use of full body scanners. One study shows that an average person may be exposed to more radiation within an hour due to environmental radiation than when inside of a body scanner. In addition, flying in an airplane places passengers much nearer the sun and the potentially harmful radiation in its rays. The health effects caused by TSA scanners seem insignificant in comparison with these greater risks.
In the end however, the stress of a body scanner, whether for its privacy invasion or for its health risks, is not likely to stop travelers from flying anytime soon. The debate over health risks will continue until long-term studies can show negative results (or lack thereof) conclusively. The results of at least one of these studies will demonstrate, one way or another, the scanners’ effects on biological tissue. Until then, travelers should be prepared to see backscatter X-ray scanners or millimeter wave scanners next time they choose to fly.