Radiological Terrorism – ‘Dirty Bombs’ and Beyond

There is a need for preparedness and public awareness to guard against the terrible possibility of radiological terrorism.

Policemen stands guard near an area where dangerous radioactive medical material was found on a truck, in the town of Hueypoxtla, near Mexico City, December 5, 2013. Credit: Reuters/Henry Romero

Policemen stands guard near an area where dangerous radioactive medical material was found on a truck, in the town of Hueypoxtla, near Mexico City, December 5, 2013. Credit: Reuters/Henry Romero

In a pre-Nuclear Security Summit activity, the Nuclear Threat Initiative (NTI), a nonprofit, nonpartisan organisation working to reduce global threats from nuclear and other WMDs, released a ‘Radiological Progress Project Report’ on March 23. The report, while reviewing the progress made by 23 of the participating states (including Australia, Canada, Denmark, Germany, Italy, Japan, Kazakhstan, Republic of Korea, Turkey, UAE, UK, and the US) in their commitments, in accordance with the ‘2014 NSS Joint Statement on Enhancing Radiological Security’, aimed to raise “awareness and urgency to reduce the threat of the use of dangerous isotopes, develop a more effective system for securing radioactive sources, and replace the use of dangerous isotopes…” India was not party to this particular gift-basket from the previous summit.

However, in his visit to Washington for the 2016 Nuclear Security Summit, Prime Minister Narendra Modi announced several key initiatives taken by the government in the area of nuclear security and nonproliferation, and also confirmed that India would be “joining the three ‘gift-baskets’ for this summit in the priority areas of countering nuclear smuggling, nuclear security contact group in Vienna, and sharing of best practices through Centres of Excellence.” Additionally, he assured the “strengthening of the national detection architecture for nuclear and radioactive material, along with a plan of using vitrified forms of vulnerable radioisotopes such as cesium-137.”

Before 9/11, the use of radiation and its harmful effects was considered in at least two popular instances: General Douglas McArthur had suggested sowing “dangerous levels of radioactivity” along the Korean-Chinese border to prevent the Chinese from playing any further role on the ground in the Korean War; later, Saddam Hussein, in his efforts to acquire chemical, biological, radiological and nuclear (CBRN) capabilities, was believed to have experimented with the development of ways to disseminate radioactive material. In the aftermath of the events of 9/11 and al Qaeda’s subsequent announcement of their inclination toward using WMDs, a lot of attention was given to the possible use of so-called ‘dirty bombs’. However, as the threat from al Qaeda waned and with no reported activity on the use of the dirty bombs, so did the threat perception surrounding them.

But more recently, with the rise of the Islamic State (IS) and the increased level of terrorist activities in Europe, the discussion over the level of threat from nuclear and radiological terrorism has once again found some traction in the Western countries. Some have argued that the possible risk of use of nuclear and radiological material might just be higher than it has previously been, and yet there are others who don’t want to attach a sense of alarmism to such a threat just yet. In the Indian context, what is alarming is the lack of media or public attention and knowledge on the issue of radiological security and the threat from non-state actor use of radiological materials (i.e., radiological terrorism). Hence, with the long history of evolving and sophisticated attacks of terror in urban centres of India, there is a need for more public discourse on the nature of such a threat.

Radiological Terrorism 101

There are tens of thousands of functioning radioactive sources in over 100 countries, and these sources find applications in multiple medicinal (including cancer treatment), industrial, and agricultural purposes. While these sources are highly beneficial for mankind, some of these very same sources, however, can also be critical ingredients for a Radiological Dispersal Device (RDD), more generally termed as a ‘dirty bomb’.  

Radiological terrorism falls under the broader umbrella of CBRN (Chemical, Biological, Radiological and Nuclear) Terrorism/WMD (Weapons of Mass Destruction) Terrorism. Simply, radiological terrorism can be defined as the intentional and malicious use of radiation from the decay of radioactive materials to cause injury (fatal or otherwise) to person or property by unlicensed exposure through a particular device or method. The notable exception here is the use of nuclear yield-producing devices (Improvised Nuclear Devices or INDs), which would fall under the purview of nuclear terrorism, as such a device would involve the injuries/deaths being caused by a nuclear fission or fission-fusion reaction leading to a nuclear explosion.

What is a ‘dirty bomb’?

A ‘dirty bomb’ is defined as a crude device that is intended to disperse powdered (or ground) high-risk radioactive material through the detonation of a mixture of said radioactive material and varying quantities of conventional explosives.

What are the high-risk radioactive materials?

From a security risk point of view, radioisotopes having what we may call “intermediate” half-lives, i.e., ranging from a few days to about a thousand years are of specific concern. A majority of radioisotopes either have a very short or very long half-life, and so that leaves us with about a couple of dozen radioisotopes that match the criteria of having intermediate half-lives. Add to that the high level of prevalence of use of such a group of radioisotopes in commercially used and widely available radioactive sources, and we are left with no more than a dozen high-risk radioisotopes.

Cobalt-60 (Co-60), cesium-137 (Cs-137), strontium-90 (Sr-90), iridium-192 (Ir-192), among others, are some of the highly radioactive isotopes that are widely used in various medicinal, commercial, and industrial sources of applications including sterilisation and food irradiation, single- and multi-beam tele-therapy, industrial radiography, high- and medium-dose brachytherapy, research and blood irradiators, level and conveyor gauges, radioisotope thermoelectric generators, etc. The International Atomic Energy Agency, keeping in mind the potential harm to human health, has categorised the commercially used radioactive sources based on radiation safety hazards as high-risk Category 1, 2, and 3 sources.

The relative security threat from each of these isotopes will vary and some of them will pose a bigger threat than the others depending upon: the amount of particular radioisotope present in a radioactive source & the corresponding specific activity (amount of material decaying per second) of the isotope; the type of radiation emitted (alpha, beta or gamma); and, the kind of exposure (internal or external). The respective half-lives also play a role in establishing the threat potential of a radioisotope. So, there are a lot of permutations and combinations that go into selecting the right amounts of the right radioisotope.

Is a ‘dirty bomb’ the only malicious way of disseminating high-risk radioactive materials?

Generally, the threat from radiological terrorism is almost exclusively restricted to the use of ‘dirty bombs’ – which is technically just one type of a Radiological Dispersal Device (RDD), which itself is one of the different possible ways of disseminating radioactive materials. While, a ‘dirty bomb’ may well be the most plausible form of dissemination of radioactive materials, a complete disregard for other forms of dissemination can lead to a misappropriation and limitation of the perceived threat from radiological terrorism.

Can there be other radiological weapons?

Drawing from a proposed definition by George Moore, a radiological weapon can more simply be defined as any device or method, except for a nuclear yield-producing device, that intentionally and maliciously uses, or intends to intentionally and maliciously use, radiation from the decay of radioactive materials to cause injury to person or property by unlicensed exposure.

Thus, in addition to a ‘dirty bomb’, other types of RDDs may comprise the spread of radioactive materials through non-explosive and passive or active means. The design and form of attack of a dirty bomb limits the use of a gamma emitting radioactive material to maximise the external radiation threat. However, in their 2007 study, James Acton, Brooke M. Rogers, and Peter D. Zimmerman have suggested alternative non-explosive forms of radiation dispersal, focussing on terrorist intention to killing by inducing large internal radiation doses (bringing into play a larger number of alpha and beta emitting radioactive materials, which are highly dangerous once inside the body) through what they described as the “inhalation, ingestion, and immersion, or I3, attacks”.

The scenarios include the spreading of radioactivity through dissemination of radioactive materials in an aerosolised form to be more effective in getting the targets to inhale them. Sprayers can be used in crowded streets or at iconic sites of a city; airplanes used for crop dusting can also be employed to do the same. The aerosolised material can even be disseminated through ventilation systems in closed places such as theatres, concert venues, sports arenas, etc. Even the intentional spreading of materials by mail (similar to the Anthrax attacks) would constitute an RDD. If carried out successfully, the I3 attacks can be operationally more useful and at the same time presumably easier to carry out for the non-state actors. Unlike a dirty bomb attack, these attacks may take longer to be identified, leading to a wider spread of contamination. A relevant example here would be the use of Polonium-210 (possibly by the Russian government) to poison Alexander Litvinenko, a former KGB agent. He reportedly died within three weeks of being exposed to the radioactive material. It was already too late by the time it could be successfully detected that he was in fact suffering from radiation sickness.

Radiation Emission Device (RED) is another possible type of radiological weapon, which can include an unshielded stationary or mobile radioactive source that is emitting radiation. This type of device can be used to expose: a large number of people (a large source of highly radioactive material placed in a crowded place or being moved around through a large crowd – for instance, a device placed in a metro or train compartment); or, a specific or a small set of individuals (a smaller source and amount of highly radioactive material placed in close proximity – for example a device concealed in a part of the office of particular high-profile victim/s).

What are the possible effects of a radiological attack?

The most relevant case-study for understanding the scenarios of widespread malicious dispersal of radioactive material was the non-terror radiation accident in Goiania, Brazil, in 1987 – where a mishap initiated by the callousness in disposing an old radio-teletherapy machine in Goiania led to the death of 5 people. Scrap metal scavengers took away the source capsule from the machine, which contained about 1375 Curie of powdered Caesium-137, and later one of the scavengers punctured the source capsule which allowed the powder to leak out.

What are the health effects?

Different types of radiations interact with and damage the human body differently, and this is expressed by a factor called the Relative Biological Effectiveness (RBE). For example, if ingested or inhaled a material emitting alpha radiation is more potent. Thus, the effective radiation dose is the product of the energy deposited by the ionising radiation and the RBE for that particular type of radiation, and is measured by Roentgen Equivalent Man (rem) in the traditional system (SI unit: Sievert (Sv). Broadly, radiological health effects can be classified as deterministic and stochastic.

As the name suggests, a deterministic effect is one where classic symptoms like radiation sickness (haematological effects, vomiting, loss of hair, likely death etc.) or radiation burns on the skin will be invoked and observed fairly instantly depending on the effective radiation dose received. Having said that, the threshold dose for deterministic effects is very high for external exposure from radioactivity. Loss of white blood cells is evident typically at doses in excess of 50rem (at times, some individuals can be affected by doses around 25-50rem). Victims exposed to doses in the range of 100-300rem experience vomiting and other symptoms of mild to high radiation sickness. Doses of 400-500rem and above are considered increasingly lethal to the exposed population. If inhaled or ingested (internal exposure), even a small quantity of an alpha emitter can deposit a high enough dose to bring about considerable deterministic health effects in the exposed population. For example, one gram of Americium-241 (Am-241), which can be found in smoke detectors, can produce over one million doses of 500rem or more to the whole body over the course of a year.

A stochastic effect, simply put, is the degree of carcinogenic impact from low levels of radiation exposure leading to an increased risk of delayed development of cancer and other health problems in a lifetime. Those exposed to doses in the range of 10s of rem are likely to have a higher probability of premature ageing, genetic effects and risk of development of cancer and tumours.

In the Goiania incident, around 250 people were identified as contaminated at the emergency response centres, of which 49 were admitted for further treatment. Out of the 49, around 20 people were reported to have received doses between 100-800 rads, which finally resulted in the death of five people.

What are the economic effects?

A successful and large-scale RDD attack in strategic and iconic locations in an urban city, can lead to a large-scale economic disruption. Such an attack could lead to a temporarily indefinite shutting down of the affected area, till the area is fully decontaminated and the radiation levels are restored to below the usual background levels. The present decontamination techniques are largely restricted in their effectiveness to say the least and according to relevant U.S. government officials, “existing decontamination techniques and procedures cannot facilitate quick, efficient recovery in a large urban environment” and that in the case of large-scale radiological terror acts it could take “billions of dollars and years or even decades to complete” decontamination efforts of such a massive scale. Additionally, if the affected area were a commercial hub or a market (shopping or stock), all trade and businesses, small or large, and related economic activity would come to a halt. Depending on the time to completely decontaminate the concerned area, it would be long before any commercial activity can resume. This resumption could be further affected by the reluctance of people to head back to the area, as the fears of radiation will continue to exist in people’s memories.

85 buildings in the city of Goiania were identified as being significantly contaminated, of which 7 were deemed uninhabitable and subsequently destroyed. A total of over 3500 cubic metres of radioactive waste was collected and disposed. With agriculture being the primary occupation in the area, the event led to “the almost absolute interruption of the economic intercourse with the rest of Brazil”.

What are the psychological effects?

Furthermore, an act of radiological terrorism will, in all probability, cause distress and a psychological disorder among those directly affected by it, and is also very likely to have strong psychological impacts of different sorts even on those not directly affected. Initially, these effects will emerge in the form of spread of mass hysteria born out of the misinformed fears of radiation, leading to a disruption of the social order and overwhelming the already stretched emergency response and medical systems. The ones who had property and/or businesses or jobs in the affected area, as discussed earlier, will be dealing with the psychological effects of such heavy economic losses and livelihoods. A temporary moratorium might be placed by the government, on the city’s/area’s population on travelling to other parts of the country, invoking feelings of being ostracised, causing further psychological damage.

All of the above effects were observed in the case of Goiania, as around 112,000 people lined up for monitoring outside the emergency response centres. Additionally, a brief moratorium was placed on the people of Goiania which prevented them from travelling to other parts of Brazil.

Thus, to build on the effects observed in Goiania, an act of radiological terrorism is expected to only be that much more disruptive by its virtue of being a planned and malicious act of intentionally disseminating radioactive material. While, a radiological attack is unlikely to cause mass casualties, but, the scope for stochastic health effects, huge economic losses, and terrifying psychological and societal effects, is a significant one. This is perhaps why such a device is considered to be a weapon of mass disruption and not mass destruction.

To provide a more contemporary context to the possible effects of a large and successful radiological attack, let us consider the case of the recent terror attack on the airport and the metro station in Brussels. The explosions led to multiple deaths and injuries and also resulted in the shutting down of the particular airport terminal for a few days. Now imagine if instead of conventional explosions, these were in fact ‘dirty bombs’ that exploded at the airport and the metro station. In addition to the deaths and injuries caused by the explosions and other health effects from the radiation, there would be enormous economic losses – owing to the direct and related costs of a complete shut down and decontamination of the entire airport and the metro system for an indefinite period of time. The resulting psychological effects and societal effects would be even more disastrous and would possibly result in widening the already existing religious and socio-ethnic cleavages, leading to a violent backlash across the globe.

What is the scope of the threat in India?

The potential for radiological terrorism in a volatile region like South Asia, and especially India, can be identified as a sum of: the persistence of terrorist threats and attacks from various non-state actors in the country and the region (where groups have shown a proclivity towards sophisticated means of causing mass disruption and deaths); and, the wide availability of commercial radioactive sources in places with less stringent security measures like hospitals and universities, etc. The possible acquisition pathways of getting hold of radioactive materials/sources can include theft from the various facilities holding such sources, insider threat, fraudulent purchase of radioactive sources, and orphaned sources.

Radiological terrorism, with its ability to cause mass disruption and not apocalyptic destruction (associated with a non-state actor use of nuclear weapons), can be viewed as a complex and unanticipated extension to conventional terrorism. At worst, radiological terrorism can offer an added dimension of the fear of the unknown and can be a potent way of bringing about mass disruption through deaths, radiation injuries, and a psychological, political, and economic breakdown of society and possibly the breakdown of the state’s machinery.

Having said that, and in assuaging the alarmist fear of the possibility of an act of radiological terrorism, it should also be noted that the list of Indian regulatory, legal, and other official provisions for the safety and security of radioactive sources is exhaustive. On paper, the institutional infrastructures are strong, comprehensive, and in accordance with the international standards. This was reinforced further by PM Modi in his recent assurances at the 2016 NSS.

Other than the threat issued by Chechen rebels in 1995 of releasing radioactive material in one of Moscow’s iconic parks and al Qaeda’s broad expression of interest in using CBRN weapons, there has been no known instance of radiological terrorism. The probability and potential of a particular act of terrorism is usually contingent on two important factors: capability of carrying out the act, and the motivation and perceived benefit (for the non-state actor) of carrying out the act. So, in conclusion, it can be said that while implementation of provisions to prevent non-state actors from gaining access to radioactive materials, and a perceived lack of motivation among terrorist groups of carrying out such an act of terrorism thus far, suggests that the threat of radiological terrorism may not be as acute as is made out to be at times, yet there is a need for preparedness and public awareness to guard against such a terrible eventuality.

Uday Deshwal works on South Asian and other global security and conflict issues, and is an alumnus of the Department of War Studies at King’s College London. He has previously worked as a Research Associate at the Centre for Air Power Studies, New Delhi.