The impact of an isotopic effect on the interpretation of bioassay data for Pu.

A review of the aggregate recoil phenomenon and its potential influence on transfer rates of 238PuO2 and 239PuO2 across the human alveolar wall indicated a significant difference between these two isotopic compounds. Transfer rates were determined in in-vitro experiments and the ratio of the transfer rates for 238Pu to 239Pu was approximately 140 (Ry82). Calculations were performed to assess the importance of this finding on the internal dosimetry of insoluble 238Pu, using methods and models recommended by the International Commission on Radiological Protection (ICRP). It was found that the committed dose equivalent per unit intake was not influenced by the transfer rate from the pulmonary compartment to blood.