Terror attacks using nuclear or radiation-related devices are an unequivocal threat in the twenty-first century and are capable of having unique medical and psychological effects. This chapter will focus on the most probable scenarios of possible attacks and the medical principles of handling such threats.
There are two major categories of potential terrorist incidents with widespread radiologic consequences. The first is the use of radiologic dispersal devices. This could cause a purposeful dissemination of radioactive material without nuclear detonation by using conventional explosives with radionuclides, attacking fixed nuclear facilities, or attacking nuclear-powered surface vessels or submarines. Malfunctioning nuclear weapons that are detonated with no nuclear yield (nuclear "duds") and installation of radionuclides in food or water are also possible means of generating a terror attack. The second and less probable scenario is the actual use of nuclear weapons. Each scenario has its own medical aspects, including "conventional" blast or thermal injury, introduction to a radiation field, and exposure to either external or internal contamination from a radioactive explosion.
Types of Radioisotopic Radiation
Isotopes of atoms with uneven numbers of protons and/or neutrons are typically unstable; such isotopes discharge particles or energy to matter, a process that is defined as radiation. The main radiation types are alpha, beta, gamma, and neutrons.
Alpha (α) radiation consists of heavy, positively charged particles that contain two protons and two neutrons. Alpha particles usually are emitted from isotopes with an atomic number of ≥82, such as uranium and plutonium. Due to their large size, alpha particles have limited penetrating power. Fine obstacles such as cloth and human skin usually can stop them from penetrating into the body, and they represent a small risk with external exposure due to their limited penetration. If they somehow are internalized, alpha particles can cause significant cellular damage in their immediate proximity.
Beta (β) radiation consists of electrons, which are small, light, negatively charged particles (about 1/2000 the mass of a neutron or proton). They can travel only a short finite distance in tissue, depending on their energy. Exposure to beta particles is common in many radiation accidents. Radioactive iodine released in nuclear plant accidents is the best known member of this group. Plastic layers and clothing can stop most beta particles, and their penetration is measured to be a few millimeters. A large quantum of energy to the basal stratum of the skin can cause a burn that is similar to a thermal burn and is treated as such.
Gamma (γ) rays and x-rays (both photons) are similar. Gamma rays are uncharged electromagnetic radiation discharged from a nucleus as a wave or photons of energy. X-rays are the product of abrupt mechanical deceleration of electrons striking a heavy target such as tungsten. Gamma rays and x-rays have similar properties, (i.e., no charge and no mass, just energy). Both travel easily ...