Meet Reference Man, a kind of hypothetical Ken Doll: a 20-something white male, fit and hearty, out in the park doing a hundred one-armed pushups every morning at 5:30. He's the guy most radiation exposure standards are designed to protect. But as a stand-in, he's passé. Reference Man was born when most of the evidence about the health effects of radiation came from high-dose exposures such as nuclear bombs. But the landscape has changed. Exposure now comes from low and often chronic levels of radiation such as medical technologies, which are the fastest-growing source of radiation exposure. Emerging science is eroding central assumptions about radiobiology. Effects at repeated low doses are different and subtler than those from episodic high doses. And mysterious, intertwining, and sometimes contradictory phenomena hint at both serious health risks and surprising benefits: cells communicate extensively about exposures, taking radiation's influence far beyond the genome; cancer may not be the only harmful consequence; low-level exposure may enable organisms to build up a tolerance that would protect them from high doses; and healthy cells can give radiation-damaged cells the equivalent of a death sentence to stop the threat of disease...read more>>>...
