Order Code RS21766
March 10, 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 the controversies surrounding the health effects of low-level radiation,
concerns related to decontamination following an RDD attack, and the issue 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, Apendix 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. Many experts contend that there
is terrorist interest 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 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 In 1987, Iraq reportedly tested a one-ton RDD 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 determine the validity of 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, 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. The report
from this study is expected to be published in December, 2004.9
Medical Countermeasures
Currently there are few medical countermeasures against RDDs, 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 ameliorate 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
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.

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those compounds with the highest protection have significant side effects.12 Also, most
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 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.
13 For example, in 1997, it was recommended to the Department of Energy that amifostine, a
radioprotectant, not be used during planned-for radiation exposures during emergencies because
of its side effects. 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
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protections for DOE 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 Other analysts suggest such models exaggerate the seriousness
of such contamination because they are based on the linear, no-threshold radiation
standard. They claim that this level of decontamination would not be appropriate for use
following an RDD attack, and contend that some inhabited areas have naturally occurring
background levels of radiation that are higher than the level that would be required under
current EPA regulations.
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. The Department of Health and Human Services has requested for FY2005 $47
million for research activities specifically targeted at medical countermeasures to nuclear
17 (...continued)
medical countermeasures through the Office of Biological and Physical Research, found online
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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and radiological terrorism.21 The DOD request for FY2005 for research activities at
AFRRI is $12 million.22
The development of effective medical countermeasures to an RDD attack might have
significant health benefits by reducing the number of casualties. This 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 such damage.23
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 congressional interest.24
The Department of Homeland Security is reportedly assessing current radiological
decontamination standards.25 Interest may center on determination of what criteria are
used to evaluate existing radiological decontamination standards and what criteria might
be used to establish any new standards for decontamination following an RDD attack.
Some analysts claim that the decontamination standards for radiological cleanup are
too low, 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 would have a significant
psychological component due to public anxiety about radiation exposure, even if the
radiation exposure is so low as to not cause acute health effects, adherence to a stricter
standard might be necessary for public confidence.26
21 Department of Health and Human Services, Budget in Brief FY2005, February 2004.
22 Department of Defense, Exhibit R-2 RDT&E Budget Item Justification, February 2004.
23 For example, see Richard L. Garwin, “The Technology of Megaterror,” Technology Review,
September 1, 2002.
24 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.
25 “Administration To Draft Emergency Toxic Cleanup Standard Different Than Superfund,”
InsideEPA.com, October 30, 2003.
26 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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