How does internal exposure occur?

Internal exposure refers to the incorporation of radioactive materials into the body through various routes. The primary ways this can occur include inhalation, ingestion, or direct contact with the skin.

When radioactive substances are inhaled, they can enter the lungs and subsequently diffuse into the bloodstream, leading to internal contamination. Ingestion of radioactive materials can happen through contaminated food or water, allowing these materials to enter the digestive system and then the bloodstream. Additionally, direct contact with the skin could lead to radioactive materials being absorbed through the dermal layer, although this is less common compared to inhalation and ingestion.

This understanding is essential in medical dosimetry and radiation protection, as it emphasizes the need to monitor and control exposure pathways to minimize the risk of internal contamination. The other options, such as direct exposure to radiation, using safety equipment, or distance from radiation sources, pertain more to external exposures that do not involve the incorporation of radioactive materials into the body.