Sealed radioactive sources are used widely in medicine, industry, and agriculture — by doctors to treat cancer, by radiographers to check welds in pipelines, or by specialists to irradiate food to prevent it from spoiling, for example. The radioactive substance within the source is sealed within a protective container. Radioactive substances emit energetic particles or waves.
Professionals who work routinely with radioactive sources are able to do so safely because of their skill and training and because they are knowledgeable about the safety features and design of the equipment they are using.
When these sources are lost or stolen, however, they can fall into the hands of persons who do not have such training and knowledge. In such circumstances, radioactive sources may be a serious risk to anyone who comes too close to them, touches them, or picks them up, particularly if they are damaged.
Serious injuries from sealed radioactive sources happen far too frequently — at least twice each year somewhere in the world. Often those who are injured are the people who find a radioactive source, but are not aware of the risk.
The same radiation that can penetrate metal or kill tumours, can also be harmful, if it is not properly controlled. Excessive exposure to radiation can result in injuries such as skin burns. Being too close to a high activity source for too long can cause radiation sickness. Prolonged exposure to a high activity source can kill or increase the risk of cancer.
To inform people of the presence of radiation, radioactive sources have special labels. The trefoil is the international symbol that appears on all containers, materials, or devices that have a radioactive component. The word “radioactive” and the number I, II, or III may also appear on the packaging used to transport the source. These numbers refer to the type of source inside.
Radioactive sources come in a variety of shapes and sizes. They can be as small as the tip of a match or needle or as large as a paint can. High activity sources are inside a lead or other heavy material container, which acts as a protective shield. Heavy materials block radiation, making sealed radioactive source containers typically heavy.
Radiation injuries can look like a burn, but unlike thermal burns, they do not heal easily. High levels of radiation exposure may also result in symptoms of nausea, diarrhoea, and fever. Anyone with these symptoms, who has been near to or touched a package or metal container with a radioactive symbol should see a doctor immediately. Be sure to tell the doctor about any contact with a radioactive source. Remember you do not have to touch a radioactive source in order to be exposed to radiation.
Sources are sometimes lost on construction sites or when old equipment is thrown away. Lost or discarded sources can end up in scrap metal yards.
People who collect scrap metal need to know how to recognize a sealed radioactive source. Old equipment, particularly if it is unusually heavy for its size, should be checked for the radiation symbol.
The best way to prevent an accident or injury is to prevent the radioactive source from being lost or stolen in the first place.
Users should make sure that a source is kept secure at all times and, when it no longer has a useful purpose, it is properly disposed of at a licensed radioactive waste facility.