When threat becomes reality: radiological contamination September 19, 2012 - no comments
When people or other living organisms come into contact with radionuclides, they may suffer two types of contamination. External contamination consists of radionuclides attached to the skin, hair, clothes, etc. Internal contamination occurs when radionuclides enter the body or the organism.
To assist physicians in making decisions for suitable treatment, whether for one contaminated individual or many, specialists have developed and published a new operational quantity, the Clinical Decision Guidance (CDG) for different radionuclides and various kinds of intake. CDGs are intended to serve as one measure of the possible need for early treatment of individuals with elevated intake of a radionuclide, especially in mass casualty situations. If radiation exposure exceeds the maximum permissible dose, radiation damage and cancer can occur. Headache, nausea, vomiting, malaise and fatigue are the initial symptoms of radiation sickness. The risk of infection rises with the increasing destruction of immune cells. Skin and mucosal damage, internal and external bleeding and infertility are other possible complications. The greater the intensity of exposure, the higher is the fatality rate. Cancer and gene mutations are the most significant late effects of radiation damage.
Radioactive material on the surface of the body is easily detected and evaluated with a simple Geiger-Müller counter. At least 80 to 90 % of external contamination can be removed by disrobing the patient. Additional contaminated areas are then gently washed with soap and water. Removing radioactive material from the skin surface or from wounds will lower the risk that this material will be absorbed. All victims of a radiological dispersion event should initially be considered externally contaminated.
Internal contamination will occur when unprotected persons are exposed to radionuclides, and the radionuclides enter the system. There are several routes for radionuclides into the human body:
into the respiratory tract via inhalation,
into the gastrointestinal tract via ingestion,
percutaneously via transdermal absorption
through intact or damaged skin (open wounds, abrasions, or burns).
Internal contamination: definition
“Internal contamination: Radioactive contamination of organs or tissues of an organism due to intake of radionuclides (e.g., by ingestion, inhalation, through wounds, or dermal absorption)”
After entering the body, radionuclides are distributed according to their physical and chemical properties and radioactive decay characteristics. Nearly all radioisotopes behave chemically exactly like stable isotopes of the same element. Internal contamination is thus treated much the same as poisoning. This treatment is best carried out by emergency physicians and medical toxicologists.
Some radionuclides are deposited preferentially in a particular organ or tissue. Until they are excreted from the body or diminished by radioactive decay, internally deposited radionuclides will irradiate body organs and tissues.
People cannot see, smell, hear, taste or touch radioactivity. Once radiological material is released, it can affect anyone who happens to be close by, whether relief worker or victim. No one can tell immediately if they have been exposed to radiation. In addition to the victims in the immediate vicinity of an incident, it is the first responders who are particularly exposed to the threat of contamination. Yet unlike those who are victims simply by chance, fire fighters, police officers, medical, technical and volunteer relief workers enter crisis zones fully aware of the dangers. They willingly risk their health, their lives, and their safety to help and protect others. Those who dispatch them therefore carry a special responsibility for the safety of the first response teams. It should be a top priority in every contingency plan to provide first responders with everything that allows them to perform their duties as safely as possible and to focus fully on the task at hand.
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