Radiation Safety Practice Exam

What is one of the pathways through which radioactive isotopes can enter the body?

1. Absorption through the skin

2. Inhalation through the respiratory system

3. Electromagnetic radiation exposure

4. Contact with contaminated surfaces

The correct answer is: Inhalation through the respiratory system

Inhalation through the respiratory system is a significant pathway for radioactive isotopes to enter the body. When radioactive materials are present in the air as dust or gas, they can be inhaled into the lungs. From there, the isotopes can enter the bloodstream and distribute throughout the body, potentially causing biological damage due to radiation exposure. This pathway is particularly relevant for isotopes that emit alpha or beta particles, which can be harmful even in small amounts when they lodge in lung tissue. The other pathways, while they may involve radiation exposure, do not directly relate to the ingestion of radioactive isotopes. For instance, absorption through the skin can occur with certain hazardous materials, but it is less common with radioactive isotopes because the skin acts as a relatively effective barrier. Electromagnetic radiation exposure, related to gamma rays or x-rays, involves exposure rather than the ingestion or inhalation of material. Contact with contaminated surfaces may result in skin contamination but is less direct compared to inhalation, which allows substances to enter the body systemically.