Study Raises Projection For 'Dirty Bomb' Toll

January 13, 2004; Page A02
By Joby Warrick, Washington Post Staff Writer

A well-executed "dirty bomb" attack on a U.S. city could expose hundreds of people to potentially lethal amounts of radiation, researchers said yesterday in a Pentagon-funded study that sharply raises estimates of the human toll from such an attack.

The study also predicts massive financial losses -- perhaps greater than those caused by the Sept. 11, 2001, attacks -- if a large dirty bomb were set off in the heart of New York or Washington. A dirty bomb uses conventional explosives or other means to spread radiation.

"The threat of a radiological attack on the United States is real, and terrorists have a broad palette of [radiological] isotopes to choose from," says the study by the Center for Technology and National Security Policy at the National Defense University. "It could cause tens to hundreds of fatalities under the right circumstances, and is essentially certain to cause great panic and enormous economic losses."

The year-long study concludes that a dirty bomb attack is "unlikely to cause mass casualties," such as would be expected if terrorists detonated a nuclear bomb or unleashed chemical or biological weapons. But it urges U.S. agencies to rethink the widely held assumption that human casualties in such an attack would be minimal. Previous studies have predicted that few if any immediate casualties would result from radiation exposure in a dirty bomb attack.

The report calls on policymakers to take a number of steps to prepare for an attack, including stockpiling medicines to treat surviving victims.

"It is possible to kill a fair number of people and to sicken a lot more, such that you begin to stress the health care system," said Peter D. Zimmerman, a nuclear physicist who wrote the report with analyst Cheryl Loeb. "But it is also possible to make RDDs [radiological dispersion devices] less attractive to terrorists by becoming better prepared for dealing with them."

A dirty bomb has never been used in a terrorist attack, but several terrorist groups, including al Qaeda, have professed an interest in building one. Experts say dirty bombs are attractive to terrorists because they are technologically simple, yet capable of generating widespread fear and economic chaos. All that is needed is a quantity of radioactive material -- such as widely available cesium or cobalt -- and an explosive or other means of dispersal.

The economic impact of such an attack could be devastating, concludes the study, published by the Pentagon's premier education and research institution. A moderately sized device containing between 1,000 and 10,000 units of radioactivity, called curies, could contaminate an area the size of the Mall in Washington, requiring a cleanup that could last for years.

Even a small dirty bomb would force lengthy evacuations of homes and businesses for extensive decontamination, saddling property owners with enormous costs that would not be covered by standard business and homeowners' insurance. Buildings -- even skyscrapers -- that had massive contamination would have to be torn down and trucked away, the report says.

"An RDD is first of all an economic weapon," the study says. "Cost estimates to restore lower Manhattan after the September 2001 attack range up to $40 billion plus loss of economic activity. The consequences of a large or super RDD might well be more costly."

The researchers derived estimates of human casualties from extensive studies of radiation accidents, including one in 1987 in Goiania, Brazil. In that case, workers ruptured a capsule of highly radioactive cesium after they discovered it inside an abandoned radiotherapy machine. Within weeks, 249 people suffered serious radiation injuries and five died. Many of the serious injuries came from internal exposure to tiny amounts of cesium that the victims ate or inhaled. "While the amounts ingested seem extremely small," the report says, "they were more than adequate to cause death or acute radiation sickness."

Such harmful affects can be ameliorated through medical treatment, but treatment is possible only if the victims are aware that they've been exposed, the study says. It notes that many of the most troubling scenarios involve the quiet dispersal of contaminants -- with no explosions that announce the crime.

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