Which of the following represents methods used to limit internal disposition?

• A. Extended breaks
• B. Respiratory protection and engineering controls
• C. PPE alone is sufficient
• D. No controls are needed

Answer: (B)

Reducing internal contamination means preventing radionuclides from entering and distributing inside the body. The most effective ways to do this are engineering controls and respiratory protection. Engineering controls limit the amount of radioactive material present in the work environment—things like local exhaust, containment, and proper ventilation reduce airborne concentrations and keep contaminants away from workers. Respiratory protection provides a barrier to inhalation when airborne levels are still a concern, lowering the amount that can reach the lungs and enter the body.

PPE alone isn’t enough because it relies on correct use and can’t fully prevent internal uptake, and controlling exposure by simply taking breaks or having no controls would not protect against contamination. Together, reducing release at the source and protecting the worker from inhalation best limit internal disposition.