Tuesday, November 30, 2010 at 8:04AM
The Transportation Security Administration has maintained its position that backscatter and millimeter wave scanners are safe for the human body. The group's official position? "The energy projected by millimeter wave technology is thousands of times less than a cell phone transmission. A single scan using backscatter technology produces exposure equivalent to two minutes of flying on an airplane."
However, Jason Bell, a molecular biologist and biophysicist, says otherwise. In his most recent blog post, which is exhaustive, well-written and hilariously subtitled "Hide Your Kids, Hide Your Wife," he writes about his opinion on the TSA advanced imaging technology.
"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 and the plane itself without being absorbed. 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. Of course these are related and there is over-lap, but we have to compare apples to apples.
"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."
One of the most disturbing parts of Bell's statement is the claim that certain tissues absorb radiation at a higher rate. What is TSA doing to protect frequent travelers' softer tissues, including their brains, breasts and testes?
Bell's is an interesting take on a complicated issue. What's your opinion? Do you think advanced imaging technology is safe, now and/or in the long term?