assessments of America's vulnerabilities include some mention of
the nation's susceptibility to attacks by radiological dispersal
devices, or "dirty bombs." The threat is often portrayed as a
homogenous danger, but it in fact covers a spectrum of risks, not
all of which are equally serious.
Because the nature of the threat is often
misconstrued, there is no shared appreciation of the problem or how
best to address it. The reality is that the threat of a dirty bomb
attack by terrorists is a credible one, although the psychological
and economic consequences would likely far outweigh any casualties
or physical destruction. To be better prepared, the United States
national standards for emergency response,
a national system-of-systems emergency response structure,
federal resources on developing national surge
- Centralize oversight
of federal emergency medical response in the Department of Health
and Human Services,
federal expertise in emergency medical care,
- Establish better
coordination with the
The Demand for Dirty Bombs
Radiological dispersal devices are
attractive to terrorists and terrorist states. Abu Zubaydah, a key
al-Qaeda operative captured in Pakistan on March 28, 2002, was
widely believed to have told U.S. investigators that al-Qaeda was
"interested" in obtaining a dirty bomb. Although Zubaydah's
statements are unconfirmed, they appear to dovetail with evidence
reportedly seized by U.S. forces in Afghanistan. In addition, on
May 8, 2002, the FBI arrested Abdullah al Muhajir on charges of
planning a radiological attack in the United States at the
direction of al-Qaeda operatives.
Although it was never fielded, Saddam
Hussein also sought this capability. In 1987, Iraq tested a bomb weighing
1,400 kilograms that carried radioactive particles derived from
irradiated impurities in zirconium oxide. Further prototypes were designed from
the casings of 100 Muthanna-3 aerial chemical bombs. They were then
modified to a 400-kilogram weight so that aircraft could carry
more. Of the original 100, it is likely that only 25 were destroyed
and that the remaining 75 were sent to the Al Qa'Qa State
Establishment for an unknown fate.
What Dirty Bombs Are, and What They Are
first step in appreciating the threat of dirty bombs is to
understand that they are not nuclear weapons. Indeed, the only
difference between a dirty bomb and a conventional explosive is
that the dirty bomb is laced with some sort of radiological
material. Therefore, it is better to think of the threat not in
terms of the dirty bomb, but instead in terms of any devise that
disperses radioactive materials.
radiological dispersal device may not even require an explosion. It
is quite possible to separate the "dirty" from the "bomb." A
terrorist could choose any number of methods to disperse dangerous
radioactive material. The dispersion method may well be a
conventional explosion, but putting radioactive material in a
trashcan or sprinkling it on a sidewalk could also be an
effective--and covert--means of contamination.
initial destruction caused by a dirty bomb would likely result from
the explosion itself and not from the nuclear material. Its
destructive capacity would be a function of the amount and type of
explosive materials used, not of the radioactive additives. A car
bomb laced with radioactive cobalt-60 would look no different from
a car bomb without the extra material.
Likewise, the radiological affect would be
defined by the type and amount of radioactive material. A bomb with
a small amount of radioactive material might wreak economic havoc
and spread terror, but it would have little biological effect on
local populations. On the other hand, a bomb laced with large
amounts of strontium-90 (a highly radioactive isotope found in old
Soviet power generators), highly enriched uranium, or spent nuclear
fuel from a nuclear power plant could be devastating.
However, like most threats, the highest
risks are also the least likely. Not only are the more dangerous
materials much more difficult to obtain, but the successful
dispersal of a highly radioactive material would require an
extremely sophisticated terrorist.
The Practicality of Dirty Bombs
kill or sicken a large number of people would require a relatively
large weapon with highly radioactive material. A truck bomb, for
example, with 220 kilograms of explosive and 50 kilograms of
one-year-old spent fuel rods could produce a lethal dosage zone
with a radius of about one kilometer. Detonating such a device in an urban
area with a large, unsheltered population might contaminate
thousands of people or more.
Although producing such a weapon is far
easier than building a nuclear bomb, fabricating a highly effective
radiological dispersal device that could easily be transported to
its target would be difficult. Among the problems in building such
a large device is the heavy shielding required to work with a
significant amount of highly radioactive material. Otherwise, it
would melt the carrying containers and sicken or kill anyone
attempting to assemble or transport the weapon. For example, one
assessment concluded that sufficient radioactive material to
contaminate 230 square kilometers would require about 140 kilograms
of lead shielding.
While such weapons may not be practical tools for most terrorists,
the idea of martyrdom could lead some to disregard the dangers.
Distributing radiological material as a
fine aerosol (the ideal molecule size being about one to five
microns, a fraction of the width of a human hair) would require
some degree of specialized knowledge and specialized handling and
processing equipment to mill the radioactive agent and blend it
with an inert material to facilitate dispersion and increase the
risk of inhalation.
variables can significantly affect the effectiveness of an attack:
the distance from the radioactive source; the manner of dispersal;
weather conditions (extent of dispersal); the degree of protection
(e.g., buildings and overhead cover); and the type of radiation.
For example, Alpha particles--one type of radiation--travel only a
short distance, and most will not penetrate the dead, outside layer
of skin. They are harmful, however, if inhaled or swallowed. Beta
particles can penetrate the skin and inflict cellular damage, but
they can be blocked by common materials such as plastic, concrete,
contrast, gamma rays and neutrons are far more powerful and do not
lose energy as quickly as alpha and beta particles when they pass
through an absorber like clothing or walls. Heavy lead shielding,
great amounts of other shielding with absorbent or scattering
material (e.g., several feet of earth or concrete), or significant
distance (perhaps kilometers) may be required to avoid high-dose
exposure. In an
urban attack, buildings might absorb or shield significant amounts
of radiation, significantly reducing the initial prospects for
Unlike nuclear weapons, a radiological
dispersal device does not require plutonium or enriched uranium. It
requires only some form of radioactive material, which any nuclear
reactor is capable of producing. In addition, numerous medical and
industrial practices employ radioactive substances. However,
obtaining these less dangerous materials associated with industry
and the medical field would be easier than obtaining the more
dangerous materials that result from nuclear power production.
Illicitly obtaining materials is not
impossible. The United States has significant gaps in its export
however, the problems are even worse. Large quantities of
relatively dangerous radioactive material remain unaccounted
assessing the risk of foreign radioactive material entering the
United States, it is important not to be misled by media outlets
that purport to demonstrate the ease with which terrorists could
smuggle these substances into the U.S. While it may or may not be easy to
smuggle radioactive material into the United States, smuggling
harmless depleted uranium demonstrates no more than smuggling an
illegal Persian rug. Depleted uranium is a byproduct of the
manufacturing of fuel for nuclear reactors and nuclear weapons.
Simply put, it is leftovers after the highly radioactive
uranium-235 has been removed from uranium ore. The remaining
(depleted) uranium is very dense and produces minimal radiation.
The Likely Impact of a Dirty Bomb
impact of a successful dirty bomb attack on those who do not
receive an immediately lethal, incapacitating dose of radiation is
difficult to predict. Even the largest radiological dispersal
device is likely to inflict catastrophic casualties only if
long-term cancer risks are considered.
Prompt modern medical treatment can
dramatically improve survivability after radiation injury for
individuals who do not receive an initial, lethal dose of
particular, dramatic medical advances have been made in caring for
individuals with suppressed immune systems, a common byproduct of
addition, the danger of low-dose exposure from a radiological
weapon may be far less than is commonly assumed. The long-term
effect of low-dose radiation is determined by the capacity of
irradiated tissue to repair DNA damage within individual cells,
which is governed by a number of exposure, health, and genetic
factors. There is some scientific evidence that current models may
significantly overestimate the risks.
the other hand, due to public fears of radiation, an attack might
have a considerable disruptive effect--forcing mass evacuations,
creating economic chaos, and inflicting environmental and property
damage and significant cleanup costs. In 1987, for example, scrap
dealers in Goiânia, Brazil, unintentionally dispersed 137
pieces of a highly radioactive material, which required a massive
environmental cleanup. This is proportional to industrial
accidents or environmental incidents in the United States. However,
a radiological release that was intentional and associated with a
terrorist attack would undoubtedly have a psychological effect
disproportionately greater than the actual physical threat.
Thus, the fear factor is a major component
of the radiological threat. A radiological strike, in which the
fear of the unknown might be particularly acute, could trigger
severe and widespread reactions, including mass hysteria and
serious psychological casualties.
economic impact of a radiological strike should also be considered.
If contamination is extensive, just removing irradiated material
could have significant consequences. For comparison, removing
low-level radioactive waste from a biomedical research facility to
an appropriate storage facility is extremely expensive, costing
$300 or more per cubic foot. The economic consequences of an attack
would also include the cost of evacuating contaminated areas and
housing, feeding, and caring for displaced persons, as well as lost
Given the widespread availability of
radioactive material, deception, hoaxes, and blackmail may also
occur. These dangers are hardly new. In January 1979, for example,
the general manager of a nuclear facility in Wilmington, North
Carolina, received an extortion letter with a sample of uranium
Detecting the Presence of Radiation
Technologies to detect radiological
threats are fairly mature. Radiological monitors can identify
contaminated food supplies and detect dispersal devices. Passive
detection systems are relatively simple and safe to employ, but
they can be evaded by shielding. Active systems (i.e., detectors
that x-ray or irradiate an object with neutrons or high-energy
electrons) can overcome some attempts to evade detection. Active
detection, however, is more costly, inconvenient, and complex.
issue in attempting to detect radiological weapons in transit is
the problem of false positives. Many commercial items and
industrial and health care equipment employ radioactive material.
It is likely that screening will inadvertently cause the
unnecessary investigation of many items and persons. With the U.S.
transportation system handling more than 11 million tons of freight
each year, screening could significantly impede the flow of goods
and services, especially in high-traffic areas such as airports,
shipyards, and border crossings. Interspersed in this vast amount
of material are many products that include varying amounts of
some ways, searching for a radiological bomb will be like searching
for a needle in a needle stack. For example, in September 2002,
U.S. officials boarded and searched the cargo ship Palermo Senator
after detecting radiation. After several days, the source was
determined to be a harmless load of ceramic tiles, which was
emitting naturally occurring radiation.
Department of Homeland Security (DHS) already employs a variety of
passive and active sensors to screen people and cargo entering the
United States and is developing more effective and efficient
screening systems. In addition, research on detecting radiological
sources and mitigating the effects of radiation is a priority for
the department's Science and Technology Directorate.
Preparing for the Unthinkable
Efforts to secure the global supply of
radioactive material and prevent it from falling into the hands of
terrorists should continue. Improved export controls,
international monitoring, "buyback" programs, and other threat
reduction measures could reduce, if only somewhat, the global glut
of high-risk radioactive substances; but even with aggressive enforcement
programs, sufficient material will likely be available worldwide
over the next decades for any group wanting to mount a radiological
strategy rightly focuses on stopping terrorists before they can
successfully conduct an attack on American soil. However, given the
wide availability of radioactive material and the many means of
employing it in an attack, a determined terrorist could conduct a
successful strike. Fortunately, a great deal can be done to
mitigate the casualties, psychological affects, and economic
consequences of a radiological event. In addition, many of the
countermeasures that can be implemented are "dual-use." In other
words, they would also greatly facilitate a national response to
any kind of natural or man-made disaster.
Domestic efforts to prepare for a
radiological attack should focus on creating a truly national
emergency response system that would allow state and local
governments to efficiently pool their resources, effectively direct
federal assets where they are most needed, and appropriately engage
the private sector. Particularly with regard to a radiological
response, a national system should effectively perform four
functions: provide accurate and timely information, surge medical
response to the scene, ensure efficient and effective cleanup of
the contaminated area, and monitor health and environmental
Building an effective national emergency
response system could facilitate all these actions. Specifically,
the U.S. should:
national standards for emergency
response. There are no national standards for an emergency
response to a dirty bomb attack, or for that matter to any major
terrorist incident. This is a subject of some debate. Long before
September 11, experts in the field recognized that the lack of
measurable objectives would make it difficult to establish policy
goals, allocate resources properly, and establish the right balance
of local, state, and federal roles in responding to a disaster. On the other hand,
many have opposed such an initiative. The National Governors'
Association, for example, has argued against mandatory standards.
The U.S. Conference of Mayors has called for broad discretion in
funding, allowing communities to adapt resources to local needs.
In fact, current assessments of preparedness are based on voluntary
surveys and needs assessments. Both have significant shortfalls.
They lack objective measures of preparedness and consistent
criteria for determining what personnel and equipment are needed
for emergency response. Nor do these assessments account for the
biases frequently associated with self-reported information.
Establishing broad national standards is essential for creating a
rationale national response system.
The House Select Committee on Homeland Security has unanimously
approved the Faster and Smarter Funding for First Responders Act
(H.R. 3266), which includes procedures for establishing standards
for responding to radiological attacks and other types of attacks
using weapons of mass destruction. This legislation could serve as
the foundation for establishing appropriate national preparedness
- Create a
national system-of-systems emergency response structure.
Given the complex and demanding requirements of responding to a
radiological attack or other major terrorist threat, the
fundamental requirement of an effective national response system
may be to adopt a system-of-systems or network-centric approach to
emergency preparedness. Network-centric operations could increase
effectiveness by networking sensors, decision makers, and emergency
responders. In essence, this means linking knowledgeable entities
in the response to emergencies from the local level to the national
Such a system might produce significant efficiencies by sharing
skills, knowledge, and scarce high-value assets and by building
capacity and redundancy in the national emergency response system,
as well as gaining the synergy of providing all responders with a
common operating picture and the ability to readily share
information. Network-centric systems might be especially valuable
in responding to a radiological attack, where responders will have
to disseminate information quickly and accurately, surge medical
capacity, adapt to difficult and chaotic conditions, and respond to
The DHS should adopt a system-of-systems architecture to support
the National Incident Management System and focus research,
development, and acquisition programs in the emergency response
areas on those capabilities that would most contribute to building
a national emergency responder network.
- Focus federal
resources on developing national surge capacity. Over one-third of the current federal
assistance provided to state and local government is for
developing local hospital surge capacity. This funding supports a
questionable strategy. A fixed hospital-based national emergency
response system is not the answer. It is likely that local
hospitals would be quickly overwhelmed by mass casualty attacks,
particularly radiological strikes that might see thousands of
contaminated victims as well as additional thousands of the
"worried well," or unaffected individuals who seek medical
treatment out of fear.
Federal aid should strike the right balance in ensuring that the
national, state, and local governments focus on their appropriate
responsibilities. Assistance to the state and local levels should
focus on medical surveillance, detection, and communication so that
problems can be identified quickly and regional and national
resources can be rushed to the scene.
medical response capabilities in the Department of Health and Human
Services (HHS). An effective national
medical response could be key to successfully mitigating casualties
from a radiological attack. Oversight of national medical emergency
programs, however, is split between HHS and the DHS.
Bifurcating responsibility for medical response programs such as
the Metropolitan Medical Response System, National Disaster Medical
System, and National Strategic Stockpile between HHS and the DHS is
a mistake. Managing complex programs through interagency memoranda
of understanding is bureaucratic, inefficient, and unnecessary.
Clearly, transferring responsibility and budgetary oversight of
these efforts into one department or the other would increase
efficiency. HHS has the expertise and experience--which the DHS
lacks--to oversee large medical emergency response programs.
Congress should amend the Homeland Security Act of 2002 to move
responsibility for overseeing the National Strategic Stockpile, the
Metropolitan Medical Response System, and the National Disaster
Medical System to HHS.
- Enhance federal
expertise in emergency medical care.The federal government
lacks an integrated approach to emergency medicine, a key component
of responding to a radiological attack. HHS, for example, does not
have a National Institute of Emergency Medicine. Meanwhile, the
Emergency Medical Services Division, tasked with developing the
federal contribution to enhancing and guiding the emergency medical
system, is a small office within the Department of Transportation's
National Highway and Traffic Safety Administration, far removed
from other key elements of the federal emergency medical response
system in HHS and the DHS.
Congress should address the shortfall in federal expertise in
emergency medical services by moving Emergency Medical Services
Division functions to HHS and establishing an Institute for
Emergency Medicine within the National Institutes of Health that is
dedicated to spearheading emergency medical research efforts. This
institute should work closely with the Centers for Disease Control
and Prevention to devise more comprehensive emergency medical
response strategies, particularly with regard to radiological
- Establish better
coordination with the private sector. A significant
portion of the cleanup after a radiological disaster will be
conducted by the private sector. Potentially, in addition to
professional responders and volunteers, there are about 6.5 million
skilled construction workers in the United States who could respond
in the wake of a disaster.
Thousands of workers, for example, were
required at the World Trade Center to help in response and recovery
The response also illustrated the
challenges of being unprepared to quickly integrate civilian assets
into a dangerous emergency response environment. A safety survey of
the site found that many of these workers lacked even basic safety
equipment, including safety eyewear, dust masks, ear
protection, gloves, steel-toed boots, and hard hats. As a result,
numerous injuries occurred and long-term health concerns arose
during the course of operations.
The DHS, in concert with state and local governments and the
private sector, should explore means to pre-train and certify
construction workers; establish a registry of qualified
contractors, firms, and unions; and link them to emergency
management agencies. The DHS also needs to determine how
technologies to speed cleanup efforts and protect workers can be
rapidly distributed or contracted from the private sector when
clearer understanding of the dirty bomb threat will ensure that
policymakers are prepared to coordinate public, private-sector, and
governmental responses to a dirty bomb attack. Policymakers and the
public need to understand the costs and risks associated with dirty
bombs to invest appropriate resources for preparation and
prevention efforts as well as for consequence mitigation.
Perhaps most important is ensuring that
people do not overreact to the mere presence of radiation without
full knowledge of the extent and type of contamination.
Implementing a few commonsense policies will not only better
prepare the nation for a dirty bomb attack, but also substantially
increase America's general preparedness.
James Jay Carafano, Ph.D., is a Senior
Research Fellow for National Security and Homeland Security, and Jack Spencer is a
Senior Policy Analyst for Defense and National Security, in the
Kathryn and Shelby Cullom Davis Institute for International Studies
at The Heritage Foundation.