Let's clarify these concepts
- The action of subjecting a person or object to ionizing radiation is called irradiation. When is outside the individual, it is called external irradiation.
- Pollution is when an unwanted radioactive substance is deposited on the surface of the body or when the radioactive substances are deposited on the skin of the individual, it is an external contamination, whereas if they are incorporated into the body by ingestion, inhalation or through wounds, it is an internal contamination. In this case, radioactive substances behave inside the organism as sources of radiation, that is, they irradiate the tissues or organs in which they are deposited.
When a person undergoes external irradiation, the effects produced will depend on the dose received while close to the source of radiation. When it is no longer within the sources´s action radius, either because it is sufficiently far away or because there is a shield, the radiation exposure will completely cease.
In the case of contamination by a radioactive substance, the individual will remain exposed to radiation until the contamination is eliminated. As to external contamination, it can be easily removed by washing the contaminated surface. However, when a radioactive substance enters our body, the effects it produces will depend on the tissue or organ in which it is deposited and on the time it remains in the organism. This time varies depending on the body´s capacity to eliminate the radionuclide and its half-life (the time it takes a radionuclide to reduce its radioactive activity by half).
External irradiation can be avoided by following three basic principles
- To avoid internal contamination it is important to use masks, filters or even assisted breathing equipment when handling radioactive substances. In addition, it is totally forbidden to eat and drink in facilities that work with radioactive material.
- To avoid external contamination, the use of gloves and disposable clothing is necessary.