Radiation Safety Practice Exam

Which of the following is NOT a primary way that radioactive isotopes may enter the body?

1. Ingestion

2. Injection

3. Absorption

4. Inhalation

The correct answer is: Absorption

The primary ways that radioactive isotopes can enter the body include ingestion, injection, and inhalation, as these involve direct interaction with bodily systems. Ingestion occurs when radioactive materials are consumed through food, drink, or swallowing contaminated substances. Injection involves introducing radioactive substances directly into the bloodstream or tissue, often used in medical applications like radioactive tracers for diagnostic purposes. Inhalation refers to the process where radioactive particles are breathed in and enter the lungs, which can lead to systemic distribution. Absorption, on the other hand, can refer to a variety of mechanisms of material entering the body, often associated with topical contact or through the skin rather than being a primary route for radioactive isotopes. While it is possible for some radioactive materials to be absorbed through the skin, it is not classified as a primary entry method compared to the other three options, which are more direct and common paths for radioactive isotopes to enter the human body. Thus, this distinguishes absorption as the option that does not align with the most typical or significant routes of exposure to radioactive materials.