Contribution of inhalation by food animals to man's ingestion dose

Animals' inhalation (AI) pathway was evaluated for 57 radionuclides using infant dose predictions from the food-chain model LIMCAL. With ingestion transfer coefficients fMi to define transfer from the respiratory tract to milk, the AI pathway appeared to be insignificant compared to animals' plant ingestion, as implicitly assumed in most environmental assessment models for nuclear installations. Using ICRP Publication 30 respiratory clearance models for man to adjust ingestion transfer coefficients, animals' inhalation appeared to be important, particularly for some actinide radionuclides. The AI pathway also appeared to be significant relative to man's inhalation, especially for infants. The importance of the AI pathway varied greatly between radionuclides, and results strongly suggest that it cannot be ignored in environmental assessments. Until better data become available to implement this pathway fully, adjusted ingestion transfer coefficient values can be used for transfer from animals' respiratory tract to milk and other food products