TSA Pornoscanner safety
TSA Pornoscanner safety

The above graphic gives an indication of how heavily censored information about the scanners is. Most concern is being raised in the USA. But there have been protests elsewhere. Canada has the machines, Australia is due to start using the scanners next year.

This has resulted in a molecular biologist posting a missive that includes information and questions about the safety of the scanners. The questions relate to the fact that an X-ray beam is rastered across the body.

Unanswered questions include:

  • What happens if the machine fails, or gets stuck, during a raster. How much radiation would a person’s eye, hand, testicle, stomach, etc be exposed to during such a failure?
  • What is the failure rate of these machines? What is the failure rate in an operational environment?
  • Who services the machine? What is the decay rate of the filter? What is the decay rate of the shielding material?
  • What is the variability in the power of the X-ray source during the manufacturing process?

This last question may seem trivial; however, the Johns Hopkins Applied Physics Laboratory noted significant differences in their test models, which were supposed to be precisely up to spec. Its also interesting to note that the Johns Hopkins Applied Physics Laboratory criticized other reports from NIST (the National Institute of Standards and Technology) and a group called Medical and Health Physics Consulting for testing the machine while one of the two X-ray sources was disabled (citations at the bottom of the page).

These questions have not been answered to any satisfaction and the UCSF scientists, all esteemed in their fields and members of the National Academy of Sciences have been dismissed based on a couple of reports seemingly hastily put together by mid-level government lab technicians. The documents that I have reviewed thus far either have NO AUTHOR CREDITS or are NOT authored by anyone with either a Ph.D. or a M.D., raising serious concerns of the extent of the expertise of the individuals and organizations evaluating these machines. Yet, the FDA and TSA continue to dismiss some of the most talented scientists in the country…

With respect to errors in the safety reports and/or misleading information about them, the statement that one scan is equivalent to 2-3 minutes of your flight is VERY misleading.

Most cosmic radiation is composed of high energy particles that passes right through our body, the plane and even most of the earth itself without being absorbed or even detected. The spectrum that is dangerous is known as ionizing radiation and most of that is absorbed by the hull of the airplane. So relating non-absorbing cosmic radiation to tissue absorbing man-made radiation is simply misleading and wrong.

Furthermore, when making this comparison, the TSA and FDA are calculating that the dose is absorbed throughout the body. According the simulations performed by NIST, the relative absorption of the radiation is ~20-35-fold higher in the skin, breast, testes and thymus than the brain, or 7-12-fold higher than bone marrow. So a total body dose is misleading, because there is differential absorption in some tissues. Of particular concern is radiation exposure to the testes, which could result in infertility or birth defects, and breasts for women who might carry a BRCA1 or BRCA2 mutation. Even more alarming is that because the radiation energy is the same for all adults, children or infants, the relative absorbed dose is twice as high for small children and infants because they have a smaller body mass (both total and tissue specific) to distribute the dose. Alarmingly, the radiation dose to an infant’s testes and skeleton is 60-fold higher than the absorbed dose to an adult brain!

Hat tip Boing Boing

I can’t in good conscience paste any more of their post. Read the whole thing.

The Obama administration has imposed this on Americans. The Gillard government is on track to do the same for Australians. We do not have to put up with it.

UPDATE

In case you think the machines are effective securtity it is worth hearing what an Israeli expert, Rafi Sela, had to say. Rafi is the former chief security officer of the Israel Airport Authority and a 30-year veteran in airport security and defence technology. He helped design the security at Ben Gurion. He said:

“I don’t know why everybody is running to buy these expensive and useless machines. I can overcome the body scanners with enough explosives to bring down a Boeing 747… That’s why we haven’t put them in our airport,”

Apparently Canada bought 44 scanners earlier this year, with each machine costing $250,000.

Source: Vancouver Sun, hat tip Naked Capitalism