Removable contamination can be defined as:

Removable contamination is defined as radioactive material that can be transferred from one surface to another, often through casual contact. This means that if a worker comes into contact with a surface that has removable contamination, they can potentially carry that contamination with them, which poses a risk of spreading the contamination further or exposing themselves to radiation. The ability to remove this type of contamination is crucial for maintaining safety and cleanliness in environments where radioactive materials are handled.

In practice, removable contamination is measured using swipe tests or other monitoring methods to ensure that contamination levels are kept within safe limits. Understanding this concept is fundamental for radiological workers to minimize risks associated with radioactive materials.

Other options present different ideas that do not align with the definition of removable contamination. For instance, contamination that cannot be readily removed refers to fixed contamination, which poses different challenges and risks. Radioactive material in a desired location does not imply anything about the ability to remove it, and material with a long half-life relates more to its stability and persistence in the environment rather than its removable properties.