Next time I'm traveling free-balling in my thin nylon basketball shorts .

Radiation exposure is cumulative. All x-ray radiation exposure is dangerous. One of the scientists who signed off on the safety of the device already stated that he had thought it was only to be used as a late-stage screening for a small number of cases. He never would have said it was safe for general use every time someone flies because we don't have any prior information on the use of radiation on that scale to tell us whether it is safe. (source: http://www.npr.org/templates/story/story…)

It also concentrates the radiation in the skin and eyes and hits the testicles and ovaries more than radiation usually does, which will have hard to predict long-term effects. The general population includes people who are already at increased risks for skin cancer, and each additional bit of risk adds to their odds of getting it or getting it again.

From the wikipedia article:
"Fathers exposed to medical diagnostic x-rays are more likely to have infants who contract leukemia, especially if exposure is closer to conception or includes two or more X-rays of the lower gastrointestinal (GI) tract or lower abdomen.[34] In medical radiography the x-ray beam is adjusted to expose only the area of which an image is required, so that generally shielding is applied to the patient to avoid exposing the gonads,[35] whereas in an airport backscatter scan, the testicles of men and boys will be deliberately subjected to the direct beam, and radiation will also reach the ovaries of female subjects. Whilst the overall dose averaged over the entire body is lower in a backscatter X-ray scan than in a typical medical X-ray examination, because of the shielding of the gonads used in medical radiography this in itself does not mean that the dose to the testicles would be less in an airport scan."

Similarly, they aren't shielding people's eyes, even though there is no reason not to. It's not like anyone can sneak anything through in their eyes. And yet they are getting a burst of radiation focused at their eyes.

There is a lot of controversy about the safety of this. You would think that would mean it'd really need to show that it does improve our safety to justify its use. Even though it can't detect powder (as was used by the underwear bomber) nor anything in a body crevice. There isn't any clear likelihood of it actually improving safety, there is a clear privacy violation, and there is enough reason to worry about health concerns that it seems premature to allow it.

Scientific discussion from a letter from UCSF biologists (John Sedat PhD, David Agard PhD, Marc Shuman MD, Robert Stroud PhD) to John Holdren, Assistant to the President for Science and Technology, April 6 2010:

We are writing to call your attention to serious concerns about the potential health risks
of the recently adopted whole body backscatter X-ray airport security scanners. This is
an urgent situation as these X-ray scanners are rapidly being implemented as a primary
screening step for all air travel passengers.

Our overriding concern is the extent to which the safety of this scanning device has
been adequately demonstrated. This can only be determined by a meeting of an
impartial panel of experts that would include medical physicists and radiation biologists
at which all of the available relevant data is reviewed.

An important consideration is that a large fraction of the population will be subject to
the new X-ray scanners and be at potential risk, as discussed below. This raises a
number of ‘red flags’. Can we have an urgent second independent evaluation?

The Red Flags

The physics of these X-rays is very telling: the X-rays are Compton-Scattering off outer
molecule bonding electrons and thus inelastic (likely breaking bonds).

Unlike other scanners, these new devices operate at relatively low beam energies
(28keV). The majority of their energy is delivered to the skin and the underlying
tissue. Thus, while the dose would be safe if it were distributed throughout the volume
of the entire body, the dose to the skin may be dangerously high.

The X-ray dose from these devices has often been compared in the media to the cosmic
ray exposure inherent to airplane travel or that of a chest X-ray. However, this
comparison is very misleading: both the air travel cosmic ray exposure and chest X-
rays have much higher X-ray energies and the health consequences are appropriately
understood in terms of the whole body volume dose. In contrast, these new airport
scanners are largely depositing their energy into the skin and immediately adjacent
tissue, and since this is such a small fraction of body weight/vol, possibly by one to two
orders of magnitude, the real dose to the skin is now high.

In addition, it appears that real independent safety data do not exist. A search,
ultimately finding top FDA radiation physics staff, suggests that the relevant radiation
quantity, the Flux [photons per unit area and time (because this is a scanning device)]
has not been characterized. Instead an indirect test (Air Kerma) was made that
emphasized the whole body exposure value, and thus it appears that the danger is low
when compared to cosmic rays during airplane travel and a chest X-ray dose.

In summary, if the key data (flux-integrated photons per unit values) were available, it
would be straightforward to accurately model the dose being deposited in the skin and adjacent tissues using available computer codes, which would resolve the potential
concerns over radiation damage.

Our colleagues at UCSF, dermatologists and cancer experts, raise specific important
concerns:

• A) The large population of older travelers, >65 years of age, is particularly at
risk from the mutagenic effects of the X-rays based on the known biology of
melanocyte aging.

• B) 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.

• C) Blood (white blood cells) perfusing the skin is also at risk.

• D) 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.

• E) The risk of radiation emission to children and adolescents does not appear to
have been fully evaluated.

• F) The policy towards pregnant women needs to be defined once the theoretical
risks to the fetus are determined.

• G) Because of the proximity of the testicles to skin, this tissue is at risk for
sperm mutagenesis.

• H) Have the effects of the radiation on the cornea and thymus been determined?

Moreover, 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. Who will
oversee problems with overall dose after repair or software problems? The TSA is
already complaining about resolution limitations; who will keep the manufacturers
and/or TSA from just raising the dose, an easy way to improve signal-to-noise and get
higher resolution? Lastly, given the recent incident (on December 25th), 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?

After review of the available data we have already obtained, we suggest that additional
critical information be obtained, with the goal to minimize the potential health risks of total body scanning. One can study the relevant X-ray dose effects with modern
molecular tools. Once a small team of appropriate experts is assembled, an
experimental plan can be designed and implemented with the objective of obtaining
information relevant to our concerns expressed above, with attention paid to completing
the information gathering and formulating recommendations in a timely fashion.

We would like to put our current concerns into perspective. As longstanding UCSF
scientists and physicians, we have witnessed critical errors in decisions that have
seriously affected the health of thousands of people in the United States. These
unfortunate errors were made because of the failure to recognize potential adverse
outcomes of decisions made at the federal level. Crises create a sense of urgency that
frequently leads to hasty decisions where unintended consequences are not recognized.
Examples include the failure of the CDC to recognize the risk of blood transfusions in
the early stages of the AIDS epidemic, approval of drugs and devices by the FDA
without sufficient review, and improper standards set by the EPA, to name a few.
Similarly, there has not been sufficient review of the intermediate and long-term effects
of radiation exposure associated with airport scanners. There is good reason to believe
that these scanners will increase the risk of cancer to children and other vulnerable
populations. We are unanimous in believing that the potential health consequences
need to be rigorously studied before these scanners are adopted. Modifications that
reduce radiation exposure need to be explored as soon as possible.

In summary we urge you to empower an impartial panel of experts to reevaluate the
potential health issues we have raised before there are irrevocable long-term
consequences to the health of our country. These negative effects may on balance far
outweigh the potential benefit of increased detection of terrorists.

This product might come in handy to leave some well-placed insults that will only be seen by TSA scanner operators. http://goo.gl/j8CNL

Just want to throw it out there that the TSA is sending children thru the scanner. This is producing an image of the children naked. When children send naked pictures of themselves via text, they are put on the sexual offender list.

Matt Skala had the definitive word on this topic.

http://ansuz.sooke.bc.ca/entry/13

Our own Maria Cantwell sits on the Senate's Commerce, Science & Transportation Committee. They're holding a TSA oversight meeting this Wednesday the 17th.

If you're concerned about this, perhaps a quick call or email wouldn't go amiss?