Radionuclides may become incorporated into the body, either accidentally or intentionally, through a number of pathways. The most common are inhalation, ingestion, and injection. In the workplace (nuclear installations, national laboratories, universities, etc.), intakes are generally accidental, whereas in nuclear medicine, activity is intentionally administered to patients for diagnosis or therapy (but the medical staff may have inadvertent intakes, which would be considered to be occupational exposures, as above). There are two pages of information on this web site with resources related to internal sources of radioactivity, in either occupational settings or in nuclear medicine.