Next month I will be boarding a flight at Dulles International Airport. The last flight I took was also out of Dulles and I became familiar with their security screening; almost every security line passes through one of the backscatter x-ray scanning machines. Normally, I’m pretty cavalier about most things but when agreeing to undergo a whole body x-ray, outside a hospital, I’d like to know the risks. In 2010, a group of scientists at UCSF, including a biophysicist and an oncologist, wrote a letter to the Assistant of Science and Technology reporting directly to the president, voicing their serious concerns about the safety of these devices. They felt that the data presented by the manufacturer was misleading and did not appropriately address whether this high dose of x-rays into the skin was truly safe. Fellow blogger Mike addressed this issue back in 2010. Since the time of the letter, there has been little research done on actual scanners because “security concerns” prevent the TSA from allowing scanners into public hands.
Several radiologists have stated that these scanners are probably not harmful to those who travel just a few times per year. It is possible that older people, children and pregnant women are at a greater risk of DNA damage from ionizing radiation. It is also a public health concern when a large population of Americans who travel frequently or work in airports, are screened very often. A recent scientific study shows evidence that these x-rays delivered at the specification of the scanning machine, can deliver radiation to internal organs. These specifications also assume that the scanning machine is operating properly. Between May 2010 and May 2011 there were 3,778 service calls made about mechanical issues with back-scatter machines.
But why expose people to x-rays at all? Fellow blogger Josh has written about the cost benefit ratio involved in deciding whether risk of x-ray exposure is worth the potential to stop a terrorist. If there is a technology which can also detect non-metallic objects without delivering ionizing radiation, then its use should be promoted. An alternative to the backscatter x-ray is the millimeter wave scanning technology, which many airports already use. This method eliminates the worry that there may be potential side effects of screening all passengers and screening some passengers a great number of times.
For now, my choice is x-ray induced superpowers or a TSA pat-down. I’ve always wanted a superpower.