Derivation and validation of a urinary excretion function for plutonium based on occupational exposure

Area of Science:

• Occupational health
• Radiological protection
• Internal dosimetry

Background:

• Accurate assessment of internal radioactive contamination is crucial for occupational health.
• Plutonium exposure, particularly chronic inhalation, requires reliable models for monitoring and control.
• Existing models may not fully capture the complex urinary excretion dynamics of plutonium.

Purpose of the Study:

• To derive and validate a three-component function describing urinary excretion of plutonium.
• To establish a tool for operational uptake assessment in cases of chronic plutonium exposure.
• To enhance the accuracy of internal dosimetry for occupationally exposed individuals.

Main Methods:

• Utilized longitudinal urinary excretion data from two subjects with documented plutonium inhalation.
• Applied mathematical modeling to fit a three-component exponential function to the collected data.
• Validated the derived function for its applicability in operational settings.

Main Results:

• A specific three-component urinary excretion function, U(t) = 0.0008e(-0.0566(t)) + 0.00009e(-0.0042(t)) + 0.00004e(-0.00008(t)), was established.
• The function demonstrated a reliable fit to the observed excretion patterns over extended periods (6000 and 2500 days).
• The model is particularly suited for plutonium exposure dominated by M-class chronic inhalation.

Conclusions:

• The derived three-component urinary excretion function provides a robust basis for uptake assessment.
• This model supports improved operational control and radiological protection for workers exposed to plutonium.
• The findings contribute to more precise internal dosimetry for chronic occupational exposure scenarios.