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Radiation Emergencies

Many types of ionizing radiation sources are naturally present in our environment
Radiation sources

Radiation sources can be found in the soil, water and air and, to a lesser extent, in the food chain. They can also be found in our built environment.  

The amount of radiation normally found in our environment is called background radiation. In general, background radiation levels do not pose a health risk to humans.

Radiation sources can also be encountered in other settings and can be used in a variety of applications such as: 

  • medical uses (medical imaging, in vitro diagnostics and radiation therapy)
  • energy uses (nuclear energy for the production of electricity)
  • industrial uses (industrial radiography, nuclear gauging) Research uses (nuclear physics, technology, space and environmental science)

In order to ensure the safe and secure use of these materials, approved licensees are subject to very rigorous and stringent regulations set out by the Canadian Nuclear Safety Commission (CNSC). 


If not controlled properly, radiological emergencies can result when an event causes radioactive material in gaseous, solid or liquid forms to be released at levels high enough to impact human health. These events can be accidental or intentional (if intentional, they may be considered to be a form of radiological terrorism).


The degree to which radiation can cause harm is dependent on a number of factors, including: 

  • the type of radiation in question (x-ray, gamma, beta, alpha, neutrons)
  • the frequency and duration of exposure 
  • the type of exposure (whole body or specific parts of the body)
  • the proximity to the source (the distance between the radiation source and the exposed individual)

BCCDC emergency response 

At the BCCDC, the Public Health Emergency Management and Environmental Health service lines respond to these emergencies by working with law enforcement, health specialists, provincial and federal partners to: 

  • Identify the type and amount of radiation released
  • Analyze its current and predicted effect on human health and the environment
  • Make clear, evidence-based recommendations on how to mitigate health impacts
  • Interpret data to help stakeholders and the public understand the facts relating to issues, risks and protective measures

The BCCDC has developed guidelines for the public in the event of contact with radioactive materials

Dirty bombs

Criminals may disperse radioactive materials by contaminating drinking water or detonating a "dirty bomb". 

A dirty bomb is a weapon that uses conventional explosives to scatter radioactive material over a large area. The force of the blast from a dirty bomb is a greater threat to public health than radiation sickness or long-term health effects resulting from radiation exposure or contamination.

Small amounts of non-destructive radioactive material are used in construction and academic research and are licensed, inspected and controlled by the Canadian Nuclear Safety Commission. 

This type of radiation poses little threat to public health, even in the wrong hands. Though exposure to industrial radiation is limited, it is important to recognize the warning symbol for radiation so that you can avoid coming in direct contact with radioactive materials and areas where radioactive material is present.

Protecting yourself

Methods of protection

There are a few methods that can be utilized to protect yourself from the potentially harmful effects of ionizing radiation.  Time, distance and shielding are the three most important parameters to remember:


Minimizing the duration of exposure will reduce your risk.


The farther away you are from the radiation source the lower your exposure will be.


Having a shield or barrier between yourself and the radioactive material can significantly reduce the amount of radiation absorbed, thus decreasing your exposure. 

Potassium iodine (KI)

One type of potentially harmful radiation emission is from radioactive iodine.  If a person is internally contaminated with large amounts of radioactive iodine, he or she may have a higher likelihood of developing thyroid cancer later in life, as the absorption of iodine is one of the normal functions of the thyroid gland. 

To help minimize the amount of radioactive iodine that can be absorbed, health officials may advise at-risk persons to take stable potassium iodide (KI) which can help protect the body by saturating the thyroid with stable iodine, thereby reducing the amount of harmful iodine that can be absorbed.

It is important to note that KI only protects the thyroid and does not offer protection to other parts of the body from radiation.  It is important to follow the advice of health officials to ensure KI is not taken unnecessarily as it can cause allergic reactions in some people and may have adverse health effects if not taken appropriately.

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SOURCE: Radiation Emergencies ( )
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