Dear Dr. Dave and Dr. Dee,
Whenever I go to the airport, I opt out of those naked body scanners because I do not like the idea of my private body parts being seen, and I am worried about radiation. I do not like the feeling of being groped in the pat down either, but I have no choice. Am I being overly concerned?
Unsafe at airport
Dear Unsafe at airport,
It seems appropriate for airline passengers to have some level of apprehension about the so-called "naked body scanners" in operation in airports nationwide. Determining whether you are "overly concerned," as your friends claim, or appropriately concerned, or whether your friends are inadequately concerned, would depend upon an objective analysis of the risks and benefits of these devices.
Although the TSA (Transportation Security Administration) says that full body scanners do not pose a significant risk to public health, there has been ongoing controversy about the scanners since their implementation. The public's concerns about body scanners seem to revolve around the issues of individual privacy, the actual effectiveness in detecting threats, and the potential health risks from the radiation exposure to the health of passengers and TSA personnel. Airport security check points may have both metal detector devices and body scanners. Passengers must go through one or the other, but not normally both. At this writing passengers retain the right to voluntarily "opt out" of body scanners and receive a full body pat down.
It is worth noting that after a three-year trial in European airports, the European Commission has decided to not to give approval to using the full body x-ray scanners (Brown, L., "European Union BANS full body airport scanners over safety concerns... so why are they still allowed in the US?" dailymail.uk, 17 September 2012).
WHAT ARE BODY SCANNERS?
Body scanners are imaging devices that use back scatter radiation and/or millimeter waves to see through overlying objects such as a passengers garments in order to screen "passengers for metallic and nonmetallic threats including weapons, explosives and other objects concealed under layers of clothing without physical contact." (TSA, "How It Works Advanced Imaging Technology," tsa.gov, 2012).
There are two types of body imaging scanners, back scatter and millimeter wave (tsa.gov):
1. Back scatter: low level X-ray beams scan the body to create a reflection of the body displayed on a monitor. The controversies tend to be around the use of backscatter X-ray scanners and are addressed below.
2. Millimeter Wave: electromagnetic waves bounce off the body to create the same generic image for all passengers.
ISSUES OF PERSONAL PRIVACY
Full body scanners have been called naked body because objects can be seen hidden under clothing along with a virtual nude image of the body. According to the TSA, the image of the body is seen by an agent who cannot see you in person directly, only views the image, and then once reviewed, the image is deleted.
Some civil rights groups, like the ACLU (American Civil Liberties Union), have fanned public controversy by claiming that body scanners constitute "virtual strip searches," are a direct invasion of privacy, and as such are unconstitutional. The ACLU states that the body scanners should not be part of routine screening, but used only when circumstances are indicated for a particular individual. (ACLU: "ACLU Backgrounder on Body Scanners and "Virtual Strip Searches," www.aclu.org, January 8, 2010).
The Electronic Privacy Information Center (EPIC) has challenged the constitutionality of naked body scanners, and has filed a lawsuit to stop the entire body scanner program, which it says is "unlawful, invasive, and ineffective" (epic.org, EPIC v. DHS Suspension of Body Scanner Program, January 6, 2011).
It would appear that a rational evaluation of the body scanner program would include an analysis of legality and constitutionality versus the need to protect the public from from violent incidents which have plagued the travel industry, most notably airports and airlines.
The actual effectiveness of the body scanners in detecting threats has been seriously questioned. Body scanners were put in airports in order to detect explosives or weapons hidden on the body. However, according to the ACLU, body scanners "are not designed to detect powdered explosives or other low-density materials that pose a threat to airline safety," and human body anatomy would make it difficult to detect plastic explosives. (ACLU, "TSA Whole Body Scanners Ineffective at Detecting Explosives," epic.org, December 14, 2010).
Recently there was a Youtube video that went viral showing how one man was able to exploit the vulnerabilities of the scanner by successfully passing through it with an undetected metal object. (http://www.youtube.com/watch?feature=player_embedded&v=olEoc_1ZkfA) . He was apparently demonstrating a potential vulnerability of the scanners because they rely on a single projection (passenger facing front-wise) rather than taking two views of the passenger, one from the front and one from the side.
Clearly there are a number of contrary and contradictory opinions on the overall effectiveness of these devices in detecting threats. It would seem that an objective, comprehensive factual analysis of the claims of effectiveness vs. ineffectiveness would be required to determine whether the devices reliably do the job they were designed and implemented to do. Such a study would entail a determination of the numerical sensitivity and specificity of these devices in detecting threats. Unfortunately, most of the currently circulating opinions concerning effectiveness appear to be substantiated by little more than "hand-waving."
Because of the potential health risk from cumulative exposure, airline pilots and flight attendants requested to be opted out of body scanners and at this writing they have been exempted. There have been reports about TSA agent cluster cancers at the airport in Boston. (dailymail.co.uk, "Can TSA scanning machines give you cancer? New fears after claim government is covering up 'clusters' of disease among airport workers," June 28, 2011)
On January 31, 2012, Senator Susan Collins and a group of her colleagues introduced a bill to require an independent study of backscatter x-ray body scanners. (U.S. Senate Committee on Homeland Security & Governmental Affairs: "Senators Colllins, Akaka,, Levin, Coburn, Scott Brown Introduce Bill to Require Study, Warnings of Health Effects of Some Airport Scanners," www.hsgac.senate.gov, January 31, 2012.)
In Europe, after a three year trial, the European Commission did not give approval for continued use and the body scanners will be removed. (Brown, L., "European Union BANS full body airport scanners over safety concerns... so why are they still allowed in the US?," dailymail.co.uk, September 17, 2012).
Professors, scientists, and physicians have raised concerns about the long term health effects. Some health risks may include breast cancer and sperm mutations (Mike Adams, "Radiation scientists agree TSA naked body scanners could cause breast cancer and sperm mutations," naturalnews.com, December 3, 2010). Adams summarizes the concerns about the full body scanners below.
10 Big Concerns Voiced by Scientists (Adams, 2010)
1) Cancer in senior citizens - The large population of older travelers, greater than 65 years of age, is particularly at risk from the mutagenic effects of the X-rays based on the known biology of melanocyte aging.
2) Breast cancer - A fraction of the female population is especially sensitive to mutagenesis-provoking radiation leading to breast cancer. Notably, because these women, who have defects in DNA repair mechanisms, are particularly prone to cancer, X-ray mammograms are not performed on them. The dose to breast tissue beneath the skin represents a similar risk.
3) White blood cells being irradiated - Blood (white blood cells) perfusing the skin is also at risk.
4) HIV and cancer patients - The population of immunocompromised individuals -- HIV and cancer patients (see above) is likely to be at risk for cancer induction by the high skin dose.
5) Radiation risk to children - The risk of radiation emission to children and adolescents does not appear to have been fully evaluated.
6) Pregnant women - The policy towards pregnant women needs to be defined once the theoretical risks to the fetus are determined.
7) Sperm mutations - Because of the proximity of the testicles to skin, this tissue is at risk for sperm mutagenesis.
8) Radiation effects on cornea and thymus - Have the effects of the radiation on the cornea and thymus been determined?
9) Problems with the machine - There are a number of 'red flags' related to the hardware itself. Because this device can scan a human in a few seconds, the X-ray beam is very intense. Any glitch in power at any point in the hardware (or more importantly in software) that stops the device could cause an intense radiation dose to a single spot on the skin.
Translation: This machine does not emit a "flood light" of radiation like you might get from a dental X-ray machine. Rather, this machine emits a thin, narrow beam of radiation that is quickly "scanned" across your body, back and forth, in much the same way that an inkjet printer prints a page (but a lot faster). Because the angle of the X-ray beam is controlled by the scanner software, a glitch in the software could turn the naked body scanner into a high-energy weapon if the beam gets "stuck" in one location for more than a fraction of a second.
10) Higher radiation for the groin? - Given the recent incident (on December 25th, 2009) [passenger attempt to light explosives hidden in his underwear], how do we know whether the manufacturer or TSA, seeking higher resolution, will scan the groin area more slowly leading to a much higher total dose?
In summary, an objective scientific evaluation of these devices would go a long way to help resolve the existing controversies about airport body scanners. Obviously the debate is emotionally charged, due in large part to high anxiety on the part of the public about threats posed to their individual civil rights, questions of scanner effectiveness, and perceived risks to the health of passengers and personnel from questioned exposure to ionizing radiation. These concerns of risk must of necessity be balanced against the legitimate obvious concerns of preventing future occurrences of violent acts in airports and on airplanes, such as those that have occurred in the past, and which must be recognized by all. Currently, there are limitless opinions on these issues, but a relative paucity of reliable documentation to support the opinions. We can all hope that an objective analysis will be forthcoming that at least most, if not all of us can agree upon.
At long last, in answer to your question! "Am I being overly concerned?" Given the number of unknowns and relative shortage of documentation available to the public you are not necessarily being overly concerned. The option currently remains available for people with higher levels of concern to opt out and go through the pat-down. If you prefer to do that, that is your own personal decision and your friends have no right to criticize you. Conversely, your friends seem to have lower levels of concern, and that is their individual decision that you should respect as well.