Those whole-body scanners at the airport aren't giving you anywhere near the radiation dose of a standard chest X-ray—.1 microsevert of radiation vs. 100 microseverts, according to the director of the Center for Radiological Research at Columbia University Medical Center. That means they aren't really a health risk for individuals, though experts warn that, if the scanners becomes the primary means of airport security, used on everybody who passes through, they could pose problems on a wider, population level.
Maggie Koerth-Baker is the science editor at BoingBoing.net. She writes a monthly column for The New York Times Magazine and is the author of Before the Lights Go Out, a book about electricity, infrastructure, and the future of energy. You can find Maggie on Twitter and Facebook.