An analytical model for calculating internal dose conversion coefficients for non-human biota.

Area of Science:

• Environmental science
• Radiological protection
• Dosimetry

Background:

• Dose coefficients for non-human organisms are crucial for environmental radiation assessment.
• Existing methods often assume simplified organism geometries, like ellipsoids.
• Accurate dose conversion coefficients (DCCs) are needed for diverse species and radionuclides.

Purpose of the Study:

• To apply a previously developed analytical method for calculating absorbed fractions and DCCs.
• To assess DCCs for 15 reference non-human organisms (animals and plants) and six radionuclides.
• To compare the results with established values from the International Commission on Radiological Protection (ICRP) Publication 108.

Main Methods:

• Utilized an analytical method for determining absorbed fractions within ellipsoidal volumes.
• Calculated DCCs for alpha, beta, and gamma radiation.
• Applied the method to terrestrial, amphibian, and aquatic reference organisms with masses ranging from 8 mg to 1.3 kg.

Main Results:

• The analytical method yielded consistent DCCs for beta, beta-gamma, and alpha-emitting radionuclides.
• Results demonstrated consistency across a wide range of organism masses.
• The method's outcomes align well with reference values, despite differing calculation approaches.

Conclusions:

• The analytical method is effective for calculating DCCs in ellipsoidal models of non-human organisms.
• The approach is versatile, applicable to various radionuclides and organism types.
• Its ease of implementation in spreadsheets facilitates widespread use in environmental radiation dosimetry.