A group of scientists from the University of California-San Francisco is worried that a new generation of airport security scanners could present a cancer risk, NPR reports. But skeptics say people flying at 30,000 feet are already bombarded by cosmic rays, so a brief trip through an X-ray machine on the way to the plane is a drop in the radiation bucket.
After the "underwear bomber" incident on Christmas, the Obama administration ramped up deployment of advanced scanners that can spot explosives or weapons, NPR says. Some 1,000 new machines will be in use by the end of next year, roughly half of which are X-ray back-scatter scanners. The machines, which can look beneath passengers' clothes, expose passengers to ionizing radiation for about six seconds.