Injuries may be differentiated between those caused by a conventional blast and those resulting from radiation exposure. One of the authors had a personal experience that demonstrated some of the concerns of a potential radioactive dispersion associated with an explosive event.

Basic characteristics of blast injuries will be introduced here, but they are present in greater detail in Chapter 20.

Blast effects will depend on the amount of explosive used in the device. The blast injuries depend on the magnitude of the explosive charge and how close the victims are to the blast. There are several explosive properties to be considered. Primary blast injuries are those that occur when the blast wave travels through the body causing damage to the organs and tissues that have air and fluid interfaces, in contact with each other, such as in the lungs. When the blast wave goes through the body, the fluid is noncompressible and it is thrown or pulled into the less dense tissue. In such cases, when the blast wave goes through the chest, blood is forced into the air cells of the lungs causing additional hemorrhage. As the blast wave goes through the lung, more blood is “pulled” into the lung tissue and more hemorrhage results. Tearing of the lung tissue also results in air and blood vessels being in contact, and potential air embolism can
result. The patient can clinically have difficulty breathing, tachycardia, hypoxia, chest pain, altered mental status, and anxiety. The patient may have a syncopal episode (loss of consciousness) as well as anxiety. These patients are at risk for air embolism (air in the blood vessels) or a pneumothorax (free air in the pleural cavity). All these injuries can be serious and/or life threatening. Secondary blast injuries are those injuries caused by flying debris from the blast. Depending on the size of the blast, glass and shrapnel can penetrate the body causing major wounds and fractures. The result is that the trauma is applied directly to the body and traumatized tissue. Suicide bombings frequently include shrapnel, and these materials can contribute greatly to injury and death. Tertiary blast injuries result from the victim being thrown by the blast force against stationary objects. It is thought that the majority of injuries from the Oklahoma City terrorist event were due to secondary and tertiary blast injuries (5,6). In addition to long bone fractures and some complete amputations, skull fractures were common, and 17 children had open brain trauma. Miscellaneous blast effects, such as burn, inhalation of gases, and other types of trauma, may also occur. Falling structures may induce crush injuries, which are discussed in Chapter 21. These patients will need appropriate trauma and burn care.

Radiological effects from an explosive device will be dependent on the amount and type of the radioactive source(s) used. The radioactive exposure will depend on the type of radioactive source, how large it was, how close the victims were to it, and how long the victims were exposed to it.

Numerous sources of radioactive material are in normal use today. In the medical field, radioactive isotopes are used in the treatment of cancer modalities and include cesium-37, cobalt-60, and iridium-192. Nuclear medicine departments use certain radioactive tracer elements for investigations. In industry, radioactive isotopes are used for testing the integrity of welds in oil pipes and for detecting metal stress fractures in aircraft. Large activity radioactive sources are used in the sterilization of medical products such as syringes and intravenous drip bags. They are also used in food preparation to reduce the bacterial count of food, therefore increasing the food shelf life. They have been used to irradiate seeds. Enriched uranium-235, used as fuel rods for reactors, is also applied as a high activity source for research. It is interesting to note that the majority of serious radiation accidents that have occurred around the world have been due to accidents with industrial sources or medical therapy sources used in the treatment of cancer. The accountability of radioactive sources in the Western countries is good due to strict regulations. Departments that use these materials are required to register them as radioactive sources, and inventories together with regular spot check inspections are mandatory. In the case of a radiation accident occurring, the source and the activity of the source will be known. Unfortunately, these crucial last two factors will not be known in a terrorist event.

There are millions of packages containing radioactive materials shipped annually. Since there has not been a transportation accident resulting in a radiation exposure death since the start of radioactive materials transportation over 40 years ago, it has become standard practice to ship radioactive materials. Radiation sources from shipped packages could potentially be used as a terrorist weapon in an RDD.

To fully understand the impact of RDDs, we must put them into perspective with other methods of distributing radiation. A simple radiological device is defined as a method of spreading radioactive material without the use of an explosive device. An example of this type of device could be the placement of a device where unsuspecting people could be exposed to the radiation. Surreptitious exposure of hidden isotopes without a blast

A terrorist could place a high activity source in a highly populated location where the movement of people is relatively stationary, such as at queues or a conference venue. These sources could be placed under seats or around bars or even under buffet tables; as a result, people could receive a significant dose of radiation and develop nausea and vomiting a few hours later, blaming this on food poisoning. Generally the majority of people who develop nausea and vomiting tend to take care of themselves over the first 24 hours and not go to a doctor. If they did go to a doctor, the doctor would most often diagnose food poisoning and usually radiation would not be in the differential diagnosis. People could also develop skin lesions, such as erythema, desquamation, blisters, or even ulcers. This would generally be misdiagnosed as dermatitis, mycosis, allergies, chemical burns, or even pemphygus skin lesions. Initially, this would not be associated with ionizing radiation.

As discussed in previous chapters, this type of exposure has already occurred in Goiania, Brazil, in 1987, where thieves stole a radiotherapy source from an abandoned clinic, and broke it apart (7,8). They actually were able to get to the source of 1375 curies of radioactive cesium-137 and were heavily exposed to the radiation. They sold the machine to a scrap metal dealer. The scrap dealer, his family, friends, and others suffered from exposure, and four died. It took about two weeks to realize that this was radiation exposure. The exposure was discovered when the wife of the scrap dealer took some of the cesium source into town on a bus (exposing more people) to deliver it to a town official. The source was placed on the desk of the official where it was recognized as a high-level radiation source the following day. A major radiation accident was announced to the local population, and over 112,800 people had to be monitored, 249 were contaminated, 129 were both internally and externally contaminated, 49 were hospitalized,
28 had local radiation injury, and 4 died. There had to be extensive cleanup over several months with several homes demolished and containerized. This caused substantial fear in the local population with travel restricted in the area and an embargo of the produce of the area. A terrorist could cause such fear by hiding a similar radioactive source in a heavily populated or trafficked area, thus exposing many.

An RDD, or dirty bomb, is formed by combining an explosive agent (such as TNT) with radioactive material. These devices can cause conventional blast injuries as well as radiation injuries resulting from the dispersion of the radioactive material to the environment and surrounding population. This would be one of the easier radiation devices for a terrorist to use. It would not be difficult to obtain a radiation source or the explosives. Significant amounts of radioactive materials could be spread this way with additional conventional blast injuries.

An airplane used as a “suicide bomb” as in 9/11 could have radioactive material in it and could, on impact, spread radioactive material over a wide area. This would provide a great challenge to rescue efforts since the radioactive dust might contaminate the victims and the rescue workers as well as equipment. A similar issue was raised with the firefighters who initially did not have respiratory protection during the Twin Towers attack on September 11, 2001. The problem of inhaled contaminants and pulmonary toxicology would be compounded if they were breathing radioactive dust. Even with respiratory protection, they would still be contaminating their clothing.

If terrorists managed to obtain weapons-grade material such as enriched uranium-235 or plutonium-239, they could also use these materials in a conventional explosive device. This would cause major problems not in the short-term radiation sense, but as a result of contamination of the environment. Plutonium-239 and uranium-235, both nuclear weapons-grade materials, have very long physical half-lives and require thousands of years to decay completely. This would produce areas of contamination that would be considered as “no go” areas until decontamination was completed, which could take months to years to achieve.