Order Code RS21766
Updated December 7, 2004
CRS Report for Congress
Received through the CRS Web
Radiological Dispersal Devices: Select Issues
in Consequence Management
Dana A. Shea
Analyst in Science and Technology Policy
Resources, Science, and Industry Division
Summary
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.
Introduction
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 in order 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
1 See, for example, John Mintz and Susan Schmidt, “‘Dirty Bomb’ Was Major New Year’s
Worry,” The Washington Post, January 7, 2004, p. A1.
2 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

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as military 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 and there may be significant economic damage if there is an unwillingness
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 RDD has been used by a terrorist group,
so it is not known how potent an RDD might be as a terror weapon.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 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, generally only among those very close to the
device, but many disagree on how attractive an RDD would be to a terrorist. Some assert
that the inherent difficulties of handling radioactive material combined with few direct
casualties make RDDs less likely terrorist weapons.6 Other experts claim that terrorists
recognize the potential economic and psychological effects of such a weapon and thus
more highly value RDDs as terror weapons.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
3 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.
4 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.
5 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,
p. A5.
6 Don Oldenburg, “How Bad Would A Dirty Blast Be? Here's What The Experts Say,”
Washington Post, June 13, 2002, p. C1.
7 For a discussion of these issues, see CRS Report RS21528, Terrorist “Dirty Bombs”: A Brief
Primer, by Jonathan Medalia.

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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 health risks.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 which apply to radiation
levels below a threshold are not necessary and may greatly increase remediation costs.
As part of the effort to assess these models, the federal government funds research
into the health effects of radiation exposure through the Department of Energy, the
National Aeronautics and Space Administration (NASA), the Department of Defense
(DOD), and the National Institutes of Health. In 1998, the National Academy of Sciences
Board on Radiation Effects Research established an expert panel to assess the currently
available scientific literature regarding health effects from low-dose radiation and to
develop a risk estimate for exposure to low-dose radiation. This study is ongoing.9
Medical Countermeasures
Currently there are few medical countermeasures against RDDs, and they are limited
in scope. The 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 limit
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
8 For example, see Health Physics Society, “Radiation Risk in Perspective,” Position Statement
of the Health Physics Society, March 2001, found online at
[http://hps.org/documents/radiationrisk.pdf].
9 For more information about the National Academy of Sciences Board on Radiation Effects
Research, see online at [http://www7.nationalacademies.org/brer/].
10 See U.S. Department of Defense, Treatment of Nuclear and Radiological Casualties, Field
Manual FM 4-02.283, December 20, 2001.
11 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.
12 For an overview of radioprotective compounds, see Leo I. Giambarresi and Richard I. Walker,
(continued...)

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compounds with high radioprotection require injection for maximum efficacy. This
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 current 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
its mission.15
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 NASA has explored mechanisms of protecting astronauts against radiation
in space.17 The Department of Energy is interested in developing treatments and
12 (...continued)
“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.
13 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
emergencies. 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.
14 Leo I. Giambarresi and Richard I. Walker, op. cit.
15 For more information on the Armed Forces Radiobiology Research Institute, see online at
[http://www.afrri.usuhs.mil/].
16 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.
17 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
(continued...)

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protections for Department of Energy personnel following a radiation or radioisotope
release, and maintains a select inventory of Investigational New Drug medical
countermeasures.18
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
Radiological Contamination
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
precipitation.
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.
Oversight Issues
RDD-related Research. 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, in FY2005 the National
Institutes of Health received approximately $47 million for nuclear and radiological
countermeasure research.
17 (...continued)
at [http://spaceresearch.nasa.gov/].
18 For more information see the Radiation Emergency Assistance Center/Training Site program,
found online at [http://tis.eh.doe.gov/health/hservices/reacts.html].
19 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 .
20 See, for example, Testimony of Dr. Henry Kelly, President, Federation of American Scientists,
before the Senate Committee on Foreign Relations, March 6, 2002.

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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
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.
Decontamination Standards. Whether new decontamination standards should
be developed for RDD terrorist incidents may become an area of future congressional
interest.22 The Department of Homeland Security is reportedly assessing current
radiological decontamination standards.23 Interest may center on determination of criteria
to be used in evaluating existing radiological decontamination standards and criteria used
to establish any new standards for decontamination following an RDD attack.
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. Also, as experts claim an RDD attack may have a significant
psychological component due to public anxiety about radiation exposure, even if radiation
exposure is so low as to not cause acute health effects, adherence to a stricter standard
might be necessary for public confidence.24
21 For example, see Richard L. Garwin, “The Technology of Megaterror,” Technology Review,
September 1, 2002.
22 The Committee on Science, Subcommittee on Energy and Environment, held an oversight
hearing on this topic titled “Reexamining the Scientific Basis for the Linear No-Threshold Model
of Low-dose Radiation” during the 106th Congress on July 18, 2000.
23 Matthew L. Wald, “Pending U.S. Advice on ‘Dirty Bomb’ Exposure Is Under Fire,” The New
York Times, December 8, 2004.
24 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.

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