Guidance for Radiation Accident Management


Basics of Radiation



Safety Around Radiation Sources

Types of Radiation Exposure

Managing Radiation Emergencies

Procedure Demonstration

Types of radiation exposure

Regardless of where or how an accident involving radiation happens, three types of radiation-induced injury can occur: external irradiation, contamination with radioactive materials, and incorporation of radioactive material into body cells, tissues, or organs.

External Irradiation

External irradiation occurs when all or part of the body is exposed to penetrating radiation from an external source. During exposure this radiation can be absorbed by the body or it can pass completely through. A similar thing occurs during an ordinary chest x-ray. Following external exposure, an individual is not radioactive and can be treated like any other patient. (Refer to the sections on assessment and treatment in Hospital Emergency Care of the Radiation Accident Patient.)


The second type of radiation injury involves contamination with radioactive materials. Contamination means that radioactive materials in the form of gases, liquids, or solids are released into the environment and contaminate people externally, internally, or both. An external surface of the body, such as the skin, can become contaminated, and if radioactive materials get inside the body through the lungs, gut, or wounds, the contaminant can become deposited internally. Refer to Managing Emergencies Involving Radiation for additional information.


The third type of radiation injury that can occur is incorporation of radioactive material. Incorporation refers to the uptake of radioactive materials by body cells, tissues, and target organs such as bone, liver, thyroid, or kidney. In general, radioactive materials are distributed throughout the body based upon their chemical properties. Incorporation cannot occur unless contamination has occurred. (Refer to the section on assessment and treatment of the contaminated patient in Hospital Emergency Care of the Radiation Accident Patient.)


These three types of exposures can happen in combination and can be complicated by physical injury or illness. In such a case, serious medical problems always have priority over concerns about radiation, such as radiation monitoring, contamination control, and decontamination.

Biological Effects of Acute, Total Body Irradiation

Amount of Exposure


  • 50 mGy (5 rads)
No detectable injury or symptoms
  • 1 Gy (100 rads)
May cause nausea and vomiting for 1-2 days and temporary drop in production of new blood cells
  • 3.5 Gy (350 rads)
Nausea and vomiting initially, followed by a period of apparent wellness. At 3-4 weeks, there is a potential for deficiency of white blood cells and platelets. Medical care is required.
  • Higher levels of exposure can be fatal. Medical care is required.
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