Order Code RS21766
Updated January 26, 2006
CRS Report for Congress
Received through the CRS Web
Radiological Dispersal Devices: Select Issues
in Consequence Management
Dana A. Shea
Specialist in Science and Technology Policy
Resources, Science, and Industry Division
The threat of terrorist detonation of a dirty bomb, one type of radiological dispersal
device (RDD), has focused public attention on efforts to counter use of this weapon. An
RDD attack might cause casualties, economic damage, and, potentially, public panic,
though experts disagree on the likely magnitude of each of these effects. The impact of
an RDD attack would depend on many variables, such as meteorological conditions,
type and amount of radiological material, duration of exposure, and method of dispersal.
Issues of potential congressional interest include the level of federal funding for research
and development of medical countermeasures against RDDs and the appropriateness of
current standards for environmental decontamination following an RDD attack. This
report will be updated as events warrant.
The possibility that terrorist groups might use a radiological dispersal device (RDD)
in a civilian setting increased government and public concern about such weapons.1 This
report addresses controversies surrounding the health effects of low-level radiation,
concerns related to decontamination following an RDD attack, and issues of federal
research into RDD countermeasures.
RDDs are devices, other than a nuclear explosive device, designed to disseminate
radioactive material to cause destruction, damage, or injury.2 A “dirty bomb” is one type
of RDD, in which explosives disperse the radioactive material, but, in general, RDDs do
not require explosives. Research indicates that RDDs have little effectiveness as military
See, for example, John Mintz and Susan Schmidt, “‘Dirty Bomb’ Was Major New Year’s
Worry,” The Washington Post, January 7, 2004, p. A1.
FEMA, Risk Management Series: Reference Manual to Mitigate Potential Terrorist Attacks
Against Buildings, FEMA 426, December 2003, Appendix C, p. C-15.
Congressional Research Service ˜ The Library of Congress
weapons because of their inability to incapacitate prepared soldiers.3 RDDs may pose a
greater threat in a civilian setting. While there may be few immediate health effects from
the dispersed radiological material, long-term health risks, such as cancer, may increase.
Significant economic damage may result should people be unwilling to live or work in an
area with a higher radiation level. Experts contend that terrorists are interested in
constructing and using RDDs.4 No terrorist group has used an RDD to expose civilians
to radiation, so the potency of an RDD as a terror weapon is untested.5
Both the threat posed by terrorist RDD use and the magnitude of impact are matters
of some contention. Some experts believe that terrorists could, without great difficulty,
obtain radioactive material and construct an RDD, while others assert that obtaining
significant quantities of an intense radiation source would be difficult. They additionally
claim that radiation sources intense enough to cause casualties in an RDD attack would
be injurious to the terrorists during acquisition and use. Most experts agree that few
casualties would be likely to directly result from an RDD attack, but posit significant
economic costs arising from contamination following the attack.6 Whether terrorists more
highly value an RDD due to its potential economic and psychological effects or devalue
an RDD due to the inherent difficulties of handling radioactive material combined with
limited direct casualties is a matter of debate.7
Effects of Low-level Radiation
Experts disagree on the health effects of low-level radiation. This debate centers on
the validity of extrapolating to low radiation levels the results from scientific studies
conducted at higher radiation levels. Past and current research efforts have not yet led to
a definitive conclusion regarding the health effects of low-level radiation.
The Environmental Protection Agency (EPA) supports the approach that radiation
related health effects can be extrapolated, i.e. the damage caused by radiation exposure
Iraq reportedly tested a one-ton RDD in 1987 to assess its military usefulness. William J.
Broad, “Document Reveals 1987 Bomb Test by Iraq,” The New York Times, April 29, 2001, p.
A16. The United States also reportedly investigated radiation weapons in the 1940s and 1950s.
James L. Ford, “Radiological Dispersal Devices: Assessing the Transnational Threat,” Strategic
Forum, Vol. 136, March 1998.
See, for example, Charles D. Ferguson, Tahseen Kazi, and Judith Perera, Commercial
Radioactive Sources: Surveying the Security Risks, Center for Nonproliferation Studies,
Monterey Institute of International Studies, January 2003; Anthony H. Cordesman, Radiological
Weapons as Means of Attack, Center for Strategic and International Studies, November 2001; and
U.S. Attorney General John Ashcroft, “Al Qaeda ‘Dirty Bomb’ Plot Disrupted,” Speech given
June 10, 2003.
In 1995, Chechen separatists demonstrated an RDD capability, directing a news crew to a
container of radioactive cesium placed in a Moscow park. Michael Specter “Russians Assert
Radioactive Box Found in Park Posed No Danger,” The New York Times, November 25, 1995,
Don Oldenburg, “How Bad Would A Dirty Blast Be? Here’s What The Experts Say,”
Washington Post, June 13, 2002, p. C1.
For a discussion of these issues, see CRS Report RS21528, Terrorist “Dirty Bombs”: A Brief
Primer, by Jonathan Medalia.
is linearly dependent on the intensity of the radiation and exposure to any amount of
radiation causes increased health risks, such as an increased probability of developing
cancer. In contrast, others, including some professional associations, believe that the
linear model may overstate the health risks of low-level radiation.8 Some experts
maintain that a threshold exists below which minimal or no ill effects occur.
Supporters of the linear model posit that this model should be used in the absence
of definitive experimental evidence since it is the more cautious model. Supporters of the
threshold model point out that safety and regulatory actions that apply to radiation levels
below a threshold may not be necessary and may greatly increase remediation costs.
As part of the effort to assess these models, the federal government funds scientific
research into the health effects of radiation exposure. In 2005, the National Academy of
Sciences Board on Radiation Effects Research, assessing the current scientific literature,
issued a draft report concluding that current scientific evidence supports a linear, nothreshold relationship between cancer development and low-dose radiation.9
Few medical countermeasures exist against RDDs exposures, and they are limited
in scope. The Department of Defense (DOD) has identified treatments that ameliorate the
symptoms arising after radiation exposure, but do not treat the radiation-exposure-related
damage itself. For example, the DOD uses granisetron, an anti-vomiting drug, to allow
soldiers to complete mission goals, following which medical treatment of the radiation
effects can be provided.10 Post-exposure medical therapy is designed to treat the
consequences of radiation exposure, rather than prevent the initial radiation damage.
Medications designed to limit or prevent the damage caused by radiation exposure
are called radioprotectants. Current radioprotectants are intended as pre-exposure
treatments, and have limited application if taken after radiation exposure occurs. In
clinical settings, radioprotectants may be used during radiation cancer therapy to reduce
damage to healthy tissue.11 Many compounds provide some degree of radioprotection, but
those compounds with the highest protection have significant side effects.12 Also, most
compounds with high radioprotection require injection for maximum efficacy. This
For example, see Health Physics Society, “Radiation Risk in Perspective,” Position Statement
of the Health Physics Society, March 2001.
National Research Coucil, Health Risks from Exposure to Low Levels of Ionizing Radiation:
BEIR VII — Phase 2, Draft Report, (National Academies Press: Washington, DC) 2005.
See U.S. Department of Defense, Treatment of Nuclear and Radiological Casualties, Field
Manual FM 4-02.283, December 20, 2001.
For example, the drug amifostine is licensed for use in cancer radiation therapy. Radiobiology
Research: An Expert Panel Review Conducted by the National Institute of Allergy and Infectious
Diseases, National Institute of Allergy and Infectious Diseases, February 26, 2003.
For an overview of radioprotective compounds, see Leo I. Giambarresi and Richard I. Walker,
“Prospects for Radioprotection,” in R. I. Walker and T. J. Cerveny (eds), Textbook of Military
Medicine: Medical Consequences of Nuclear Warfare, (Falls Church, VA: TMM Publications,
Office of the Surgeon General, Department of the Army) 1989, Chapter 11.
combination of significant side effects and the need for injection has limited widespread
use of these compounds as pretreatments for non-clinical radiation exposure.13
Many post-exposure therapies remove radioactive contaminants from the body,
thereby limiting the total radiation dose. They either block absorption of radioisotopes
by internal organs (for example, potassium iodide decreases radioactive iodine uptake by
the thyroid gland) or enhance expulsion of radioisotopes through the gastrointestinal tract.
Radioisotope scavenging compounds, such as chelators, may be given to those who are
internally contaminated with a specific radioisotope to reduce the time that the
radioisotope remains in the body.
Federal Medical Countermeasure Research. The federal government
sponsors radioprotectant research. The DOD has long-standing efforts to develop
medications allowing soldiers to work in contaminated environments. For many years,
the Walter Reed Army Institute of Research supported an anti-radiation drug development
program which provided many candidate radioprotectant molecules.14 The Armed Forces
Radiobiology Research Institute (AFRRI) is a focal point of defense radiobiology
expertise, and performs research and testing of antiradiation drugs as one component of
Other federal agencies have been concerned with the development of antiradiation
medications as well. The National Institutes of Health have funded research into
combination therapies using radioprotective compounds to enhance radiation treatment
for cancer patients. In 2003, the National Institute of Allergy and Infectious Disease
organized an expert panel to review and identify areas where specific gaps in RDD-related
radiation research and development occur and to generate research priorities to address
these gaps.16 The National Aeronautics and Space Administration (NASA) has explored
mechanisms of protecting astronauts against radiation in space.17 The Department of
Energy is interested in developing treatments and protections for Department of Energy
personnel following a radiation or radioisotope release, and maintains a select inventory
of Investigational New Drug medical countermeasures.18
For example, in 1997, it was recommended to the Department of Energy that, because of its
side effects, amifostine, a radioprotectant, not be used during planned-for radiation exposures in
Joseph F. Weiss, “Pharmacologic Approaches to Protection against
Radiation-induced Lethality and Other Damage,” Environmental Health Perspectives, Vol. 105,
Supplement 6, December 1997, pp. 1473-1478.
Leo I. Giambarresi and Richard I. Walker, op. cit.
For more information on the Armed Forces Radiobiology Research Institute, see online at
Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious
Diseases, Radiobiology Research: An Expert Panel Review Conducted by the National Institute
of Allergy and Infectious Diseases, February 26, 2003.
In addition to research on physical shielding of astronauts, NASA has funded research into
medical countermeasures through the Office of Biological and Physical Research, found online
For more information see the Radiation Emergency Assistance Center/Training Site program,
Among the research activities sponsored by the federal government are several
public/private partnerships involving cooperative research and development agreements
(CRADAs). These CRADAs allow for joint development of prospective medications
between federal agencies and private companies. For example, Hollis-Eden
Pharmaceuticals entered into a CRADA agreement with Uniformed Services University
of the Health Sciences to develop a prospective radioprotectant drug.19
Some experts believe that the economic and psychological effects from an RDD
attack would outweigh the direct medical costs. These experts, weighing the current
guidelines on radiological contamination and the degree of dispersal expected with a
successful RDD attack, state that an RDD attack could contaminate large areas. Because
the dispersal of radiological material would likely be uneven, the level of radiation in
different areas would vary depending on meteorological factors, such as wind speed and
Some models of an RDD event have suggested that the release of finely ground
radiological material might contaminate many city blocks to a level higher than the
current EPA standard.20 Some analysts suggest such models exaggerate the seriousness
of such contamination because they are based on the linear, no-threshold radiation
standard. They claim that concerns related to this level of contamination are overstated,
and contend that some inhabited areas have naturally occurring background radiation
levels higher than the level current EPA decontamination standards require.
RDD-related Research and Development. A matter of some contention is
whether the threat of terrorist RDD use justifies an expansion of federally funded research
on anti-radiation therapies. In addition to DOD research performed at AFRRI, the
National Institutes of Health has increased research into nuclear and radiological
The development of effective medical countermeasures to an RDD attack might have
significant health benefits by reducing the number of casualties. Lower potential
casualties might act as a disincentive to terrorist acquisition of such weapons. Health
effects from radiological dispersal may vary widely and some analysts assert that the
found online at [http://www.eh.doe.gov/health/hservices/reacts.html].
Written testimony of Richard B. Hollis, Founder, Chairman and Chief Executive Officer, of
Hollis-Eden Pharmaceuticals, before the House Armed Services Committee, Subcommittee on
Military Research and Development, March 12, 2002 .
See, for example, Testimony of Dr. Henry Kelly, President, Federation of American Scientists,
before the Senate Committee on Foreign Relations, March 6, 2002.
major damage from an RDD attack would likely be economic in nature. Additional
investment in medical countermeasures would not necessarily reduce economic damage.21
Federal efforts in developing medical RDD countermeasures might serve to reduce
the psychological aspects of an RDD attack. Validated medical countermeasures might
reduce public panic and concern about the exposure of first responders to radiation during
treatment of casualties. Alternately, a similar reduction in the psychological impact of an
RDD attack might be achieved through continuing public outreach campaigns.22
Some companies have urged the Department of Health and Human Services (HHS)
to purchase existing RDD countermeasures using Project Bioshield funds, as nuclear and
radiological devices have been determined as material threats. HHS has issued requests
for proposals related to select types of RDD countermeasures through the Project
Decontamination Standards. New decontamination standards developed for
RDD terrorist incidents may become an area of future congressional interest. The
Department of Homeland Security issued a draft protective action guideline on January
3, 2006 relating to RDD decontamination.24 This draft guideline has been criticized as
being too lenient and potentially harmful to those residing in areas contaminated by an
Some analysts claim that the decontamination standards for radiological cleanup are
too strict, and that much of the cost associated with an RDD attack would come from
removal of radiological material that has little health impact. They assert that the required
decontamination under current standards would likely create large amounts of waste.
Contaminated buildings might need to be destroyed and the rubble removed. Others view
the EPA standard as ensuring that no adverse health effects arise from long-term exposure
to RDD residue. Adherence to a stricter decontamination standard might also serve to
reduce public anxieties arising from the psychological component of an RDD attack.26
For example, see Richard L. Garwin, “The Technology of Megaterror,” Technology Review,
September 1, 2002.
Charles Ferguson and William Potter, with Amy Sands, Leonard Spector, and Fred Wehling,
The Four Faces of Nuclear Terrorism, (Monterey, CA, Center for Nonproliferation Studies,
Monterey Institute of International Studies) 2004.
For an overview of requests for information and proposals under Project Bioshield, see online
71 Fed. Reg. 173-196, January 3, 2006.
For example, see H. Josef Hebert, “Government Has ‘Dirty Bomb’ Cleanup Guide,” Associated
Press, January 4, 2006.
For example, see National Council on Radiation Protection and Measurements, Management
of Terrorist Events Involving Radioactive Material : Recommendations of the National Council
on Radiation Protection and Measurements, (Bethesda, MD: National Council on Radiation
Protection and Measurements) 2001.