Radiation exposures encountered in the ED setting may either be accidental or intentional. Accidental exposures can occur during transport, storage, or working with radioactive materials or with errors in dosing radiotherapy. Most civilian incidents involve industrial exposures from sealed radiation sources.1
Historically, there have been multiple events that have resulted in radiation injuries. In August 1945, nuclear weapons were detonated over Hiroshima and Nagasaki, resulting in nearly 200,000 acute deaths and untold numbers of resulting injuries. The 2011 Fukushima Daiichi nuclear plant disaster involved about 1000 disaster-related deaths, although no deaths have yet been attributed to radiation injuries.2 The largest reported civilian accidental exposure took place in 1987 after a radiosource was left at an abandoned radiotherapy institute in Goiania, Brazil. Due to the source’s ability to glow in the dark, its contents were widely distributed, resulting in 112,000 individuals requiring evaluation, 249 contaminations, 20 individuals requiring hospital admissions, and four deaths.3,4 In 2006, Alexander Litvenko, a defected former KGB agent, suffered a protracted gastrointestinal illness associated with leukopenia after meeting with former colleagues. His death was ruled a murder after elevated levels of polonium-210 were identified. Investigations into his murder revealed multiple rehearsals throughout England, leading to the contamination of multiple sites with potential exposures to 1693 local and international individuals.5-7
A potential intentional exposure involves the use of radiologic dispersal devices, or “dirty bombs,” that combine radioactive materials with conventional explosives. They are meant to cause injuries to those nearby, while generating massive panic and hysteria, overwhelming the local resources, damaging the local economy, and causing prolonged clean-up efforts.4
FUNDAMENTALS OF RADIATION PHYSICS
Radiation energy includes the entire electromagnetic spectrum. Ionizing radiation contains enough energy to remove electrons from an atom, generating charged particles. Sources of ionizing radiation include alpha particles, beta particles, neutrons, and energy waves, including radiographs and gamma rays.8 Table 10-1 reviews the types of radiation.
TABLE 10-1Types of Radiation ||Download (.pdf) TABLE 10-1 Types of Radiation
|Type (Symbol) ||Charge ||Penetration ||Shield ||Hazard ||Source |
|Alpha ||+2 ||Few centimeters in air ||Paper, keratin layer of skin ||Internal contamination only; requires special detection devices ||Heavy radioisotopes (e.g., plutonium, uranium, radon) |
|Beta ||–1 ||~8 mm into skin ||Clothing ||External (skin) and internal contamination ||Most radioisotopes decay by beta followed by gamma emission |
|Positron ||+1 ||~8 mm into skin ||Lead, steel, or concrete ||Interacts with electrons and releases photons of energy ||Medical tracers |
|Neutron ||0 ||Variable ||Material with high hydrogen content ||Whole-body irradiation ||Nuclear power plants, particle accelerators, weapons assembly plants |
|Gamma and radiograph ||0 ||Several centimeters in tissue ||Concrete, lead ||Whole-body irradiation ||Most radioisotopes decay by beta followed by gamma emission |
Alpha particles are relatively large in size (two protons and two neutrons), resulting in a ...