title: Basis for the ICRP's updated biokinetic model for carbon inhaled as CO2.
abstract: The International Commission on Radiological Protection (ICRP) is updating its biokinetic and dosimetric models for occupational intake of radionuclides (OIR) in a series of reports called the OIR series. This paper describes the basis for the ICRP's updated biokinetic model for inhalation of radiocarbon as carbon dioxide (CO2) gas. The updated model is based on biokinetic data for carbon isotopes inhaled as carbon dioxide or injected or ingested as bicarbonate [Formula: see text] The data from these studies are expected to apply equally to internally deposited (or internally produced) carbon dioxide and bicarbonate based on comparison of excretion rates for the two administered forms and the fact that carbon dioxide and bicarbonate are largely carried in a common form (CO2-H[Formula: see text] in blood. Compared with dose estimates based on current ICRP biokinetic models for inhaled carbon dioxide or ingested carbon, the updated model will result in a somewhat higher dose estimate for14C inhaled as CO2and a much lower dose estimate for14C ingested as bicarbonate.
authors.affiliation: Environmental Sciences Division, Building 1509, Room 205, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America.
authors.forename: Rich
authors.initials: R
authors.lastname: Leggett
mesh_terms: D002245:Carbon Dioxide / Q000097:blood*; D006801:Humans; D016273:Occupational Exposure; D000069079:Radiation Exposure; D011835:Radiation Protection; D011868:Radioisotopes / Q000097:blood*; D011874:Radiometry / Q000379:methods*; D012137:Respiratory System / Q000528:radiation effects*; D012307:Risk Factors; D014018:Tissue Distribution
chemical_list: D011868:Radioisotopes; D002245:Carbon Dioxide