Nuclear/Radioactive Incidents – Introduction

Monticello Nuclear Generating Plant, MN[4]
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A radioactive or nuclear incident occurring within the U.S. homeland or elsewhere could take a number of forms, including:

  • contamination of food or water with radioactive material;
  • placement of radiation sources in public locations;
  • detonation of radiological dispersal devices that scatter radioactive material over a populated area;
  • an attack on a nuclear power plant or a high-level nuclear waste storage facility;
  • or an improvised nuclear device.[1]

Radioactive disasters are probably the most feared by the public, although historically there have been relatively few victims. Only 5 events worldwide have prompted disaster responses. Nevertheless, a radioactive disaster can have far-reaching consequences. The explosion at Chernobyl left a radioactive cloud that covered half of the earth.

The biggest risks come from nuclear reactors and from transportation of radioactive material. Cancer therapy agents, for example, are transported all over the country. If a truck or train carrying this material were involved in a collision, large numbers of people could be exposed to radiation.[2]

About Radiation

Radiation consists of alpha, beta, and gamma particles. Alpha particles are the least penetrating, while beta particles can penetrate skin and gamma particles can easily pass through the human body and be absorbed by the tissues. All radiation damage is caused by penetration into the body. Geiger counters can detect beta and gamma particles; a special counter is needed for alpha particles.

Three types of contamination with radiation are possible. With external radiation exposure, the person is not radioactive. An example would be receiving an accidentally high dose of radiation through a computed tomography scanner. With contamination, gas, liquids, or solids are deposited on the body, and decontamination is required before the patient can enter the hospital. The most severe form of contamination is incorporation, in which radioactive atoms are taken up within cells or body structures and cause damage. Generally, radium and strontium are deposited in the bones and radioactive iodine within the thyroid.

Absorption of radiation is measured with the unit Grey:

  • 1 Gy causes nausea and vomiting in 6 to 12 hours;
  • 2 to 3 Gy, nausea and vomiting in a couple of hours.
  • Patients who absorb 5 Gy have a 50% rate of mortality from bone marrow depression.
  • The absolute lymphocyte count is a good indicator of toxicity, with <100/mL usually portending a fatal outcome. Absorption of 10 Gy leads to gastrointestinal syndrome with massive bloody diarrhea, which is also usually fatal.

Chernobyl was an example of contamination. The explosion caused radioactive substances to be deposited on people. In addition, the environment was contaminated, leading to contamination of the food chain. Fish died in the lakes, and people died for weeks and months to come.

Other large-scale episodes of contamination occurred in Goiania, Brazil, and Juarez, Mexico, where people found cobalt cancer therapy units lying around after the destruction of hospitals and took home the green, glowing balls of cobalt for their children to play with. Hundreds of people were contaminated, and it took the health care system some time to identify the cause of the multiple cases of nausea, vomiting, and diarrhea being reported.[3]



  1. U.S. Department of Health and Human Services – Public Health Emergency – Radiation Emergency: to Content
  2. U.S. National Library of Medicine – National Institutes of Health – Defining disaster: the emergency department perspective: to Content
  3. U.S. National Library of Medicine – National Institutes of Health – Defining disaster: the emergency department perspective: to Content
  4. Image Source: [Accessed: January 14, 2014]