Thyroid dose estimation with potassium iodide (KI) administration in a nuclear emergency

Area of Science:

• Nuclear safety
• Radiological protection
• Environmental health

Background:

• Nuclear reactor accidents can release radioiodine, posing a significant near-field exposure risk via inhalation.
• The thyroid gland is a primary target for radioiodine uptake.
• Oral potassium iodide (KI) is a recognized public health countermeasure for thyroid blockade.

Purpose of the Study:

• To derive and present retention functions that account for the thyroid blocking effects of potassium iodide.
• To enable more accurate estimation of thyroid radiation dose during nuclear emergencies.

Main Methods:

• Utilized a standard three-compartment model of iodine metabolism.
• Incorporated the thyroid blocking effects of potassium iodide into the model.
• Derived new retention functions and a blocking factor for KI.

Main Results:

• Developed updated retention functions that quantify the impact of potassium iodide on radioiodine uptake.
• Established a method to calculate a blocking factor, representing the efficacy of KI in reducing thyroid dose.
• Demonstrated a more accurate approach to thyroid dose estimation in the presence of KI.

Conclusions:

• The derived retention functions provide a more precise tool for assessing thyroid dose after radioiodine inhalation.
• Potassium iodide administration significantly reduces thyroid dose, and its effect can be quantified using the blocking factor.
• This work enhances preparedness and protective strategies for nuclear accident scenarios.