It’s bad enough for those of us that have to fly anywhere considering some jerk beside you may decide that this would be a great day to explode their underwear; but now the equipment being used in airports to fight this danger could be dangerous themselves.
Right now there are 52 full-body scanners in action at 23 US airports with another 1,000 suppose to be coming online by the end of 2011. What a lot of people may not know is that around half of these scanners use what is called X-ray back-scatter to peer beneath passenger’s clothing. It is the use of X-rays that has enough scientists worried that some of them wrote a joint letter (pdf) to the president’s science advisor, John Holdren.
“Many people will approach this as, ‘Oh, it must be safe, the government has thought about this and I’ll just submit to it,’” says David Agard, a biochemist and biophysicist at the University of California, San Francisco. “But there really is no threshold of low dose being OK. Any dose of X-rays produces some potential risk.”
Agard and several of his UCSF colleagues recently wrote a letter to John Holdren the president’s science adviser, asking for a more thorough look at the risks of exposing all those airline passengers to X-rays. The other signers are John Sedat, a molecular biologist and the group’s leader; Marc Shuman, a cancer specialist; and Robert Stroud, a biochemist and biophysicist.
“Ionizing radiation such as the X-rays used in these scanners have the potential to induce chromosome damage, and that can lead to cancer,” Agard says.
Not everyone foresees any real danger from the scanners because the amount of radiation used is so minuscule that it would take 5,000 trips through one of the scanners to equal even the 100-microsievert dose used in a single chest x-ray.
Neither the company manufacturing the scanners, Rapiscan, nor the government has responded to the letter from the scientists yet although there is suppose to be one come from the TSA’s Office of Security Technology at some point.