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Radiation Terror
February 21, 2003
image: ABC News

In June of last year, when Attorney General John Ashcroft announced the capture of suspected Al Qaeda sympathizer Jose Padilla, "dirty bombs" became part of America's vocabulary.

As this NOVA News Minute reports: A dirty bomb may be a terrorist's weapon of choice.

Dirty Bombs: Physical or Psychological Danger?

With the nation guarding against terrorists, authorities are on the lookout for a "dirty bomb". As shown on P-B-S's "NOVA", a dirty bomb consists of conventional explosives combined with some kind of radioactive material. Though it's often described as a poor man's nuclear bomb, it wouldn't produce a nuclear explosion.

"A dirty bomb is not a nuclear weapon, but a real threat, a real possibility," Dr. Jack Caravelli of the U.S. Department of Energy told NOVA. “It is a weapon that could wreak havoc in ways far beyond its physical consequences. And that makes it an ideal terrorist weapon.”

According to the Nuclear Regulatory Commission (NRC) fact sheet on dirty bombs, the panic that could follow an attack might be more harmful than the explosion itself. Andrew Karam, certified health physicist and the University of Rochester's radiation safety officer, agrees.

"The death toll from the panic or just acting unwisely could very well outweigh the death toll from the radiological weapon itself," he says.

CU radiation counter gague

But how much physical damage would a dirty bomb attack cause?

"A lot would depend on how big the chemical explosion was and how much radioactivity was involved in it," Karam told ScienCentral. But if the dirty bomb spreads radioactive contamination over a large area, and if that area is not cleaned up, there might be an increase in cancer rates years later.

"Up to 200 meters from the blast, if the area was not decontaminated, the risk of cancer would increase by one in ten,” Mike Levi, of the American Federation of Scientists, told NOVA.

While some scientists say that even small doses of radiation—like the amounts most likely to be dispersed by a dirty bomb—can cause cancer, others are not so sure. "There is no doubt that radiation can cause cancer. The doubt is what levels of radiation it takes to cause cancer," says Karam.

Such uncertainty can work to the terrorist's advantage, creating huge debates about how best to clean up the radioactive mess.

While scientists disagree about the health risk of long-term exposure to low level radiation, the impact could be devastating in other ways. "In some cases either the cost or the technical barriers will be prohibitive to decontaminating an area, and if people aren't willing to accept the radioactivity in that area the only feasible option will be to abandon that space," Levi told NOVA.

Even if no one is killed in a dirty bomb attack, the economic and societal fallout could be devastating.

NOVA airs this week on PBS. For more information, visit

by Orrin Schonfeld

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