Radiation emergencies are non-routine situations or events that require a prompt action to mitigate a radio-nuclear hazard or its adverse consequences for human life, health, property or the environment.
Nuclear emergencies involve release of the energy resulting from a nuclear chain reaction or from the decay of the products of chain reaction (e.g. nuclear power plant accidents such as Chernobyl and Fukushima accidents). Radiological emergencies are situations involving a radiation exposure from a radioactive source. When referring to an emergency situation regardless of its type, “radiation emergency” term is often used.
Radiation emergencies may result from misuse of radioactive sources during industrial, medical or research applications, accidental exposure to uncontrolled (abandoned, lost or stolen) radiation sources, accidents during transport of radioactive materials, but also can be combined with conventional emergencies (a fire or a release of chemical substances), natural disasters, military conflicts, or malicious acts involving radiation sources.
Radiation emergencies can greatly impact human health and the environment. The impact will vary considerably, depending on the scenario, scale of the emergency, type of radiation and exposure duration, the pathway of the exposure (external, internal, or combined), availability and timeliness of countermeasures, as well as individual characteristics of the exposed person (age, gender, underlying state of health).
As a result, people may be exposed to radiation levels ranging from very low doses not resulting in any clinical manifestations of such exposure, to higher doses which may cause radiation injuries (a.k.a. “tissue reactions”) or even be fatal. The risk of health effects increases with the radiation dose. Workers at nuclear installations, first responders and fire-fighters are at higher risk of being over-exposed to radiation and receiving radiation injures, whereas, for the majority of people affected by the consequences of a nuclear emergency, it will be unlikely to suffer the direct impact of radiation.
In addition, urgent protective actions implemented in response to a radiation emergency, such as sheltering, evacuation, or resettling from contaminated areas, restrictions on locally produced foodstuffs etc. may also lead to negative socio-economic impact on the human lives and the society as a whole. Losing homes and jobs, lack of access to a regular health care, stigmatization of evacuees and other hardship may further impact people’s health through severe stress, anxiety, fatigue, depression, and other mental health and psychosocial consequences.
As a full party to the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency, WHO has a mandate to provide technical assistance and advice on public health measures and medical countermeasures. The IAEA provides Secretariat for the Convention and for the Inter-Agency Committee for Radiological and Nuclear Emergencies (IACRNE) that brings together more than 20 international organizations for coordination of their work on preparedness and response to radiation emergencies. The roles of IACRNE member organizations are described in the Joint Radiation Emergency Management Plan of the International Organizations.
To fulfill its mandate under these Conventions, WHO established in 1987 the Radiation Emergency Medical Preparedness and Assistance Network (REMPAN) to enhance preparedness for radiation emergencies and to advise health authorities on medical and public health response in the event of a radiation emergency. The Network is WHO’s technical arm for implementing capacity building activities in member states and for providing technical assistance in case of radiation emergencies. In addition, a global network of cytogenetic laboratories WHO BioDoseNet was set up in 2008 to support biological dosimetry capacity of member states readiness for a mass-casualty type of a radiation emergency.