How a 'dirty bomb' blast may harm you

(CNN) -- U.S. officials say Osama bin Laden's al Qaeda network may possess radiological material that could be used to make a so-called "dirty bomb."

VIDEO CNN Medical Correspondent Dr. Sanjay Gupta reports on the potential effects of a "dirty bomb" (December 10) Play video (QuickTime, Real or Windows Media)

A "dirty bomb" -- or radiation bomb -- is a conventional explosive laced with radioactive materials designed more to terrify people than to kill large numbers, experts said.

Victims who are near, but survive, a radiation bomb explosion could experience imminent radiation sickness. And, some victims may not see any side effects for years.