as japan's nuclear crisis deepens, panic is gripping the island nation, with growing fears of exposure to radiation. already, 210,000 people have been evacuated or told to stay indoors, and as radiation levels surge in tokyo and beyond, foreigners are crowding airports trying to get out of japan. >> i don't know if it's common knowledge but it affects children and elderly the most. i think everyoneness scared for chair child's safety and trying to get out children first. >> dr. david brenner, professor of radiation at biophysics. we've heard talk of radiation levels ten times the norm. should we be worried about the effect of that on the human body? >> really, at those levels the risks are going to be very, very small, indeed. i think all of our concerns are,