NCRP report no 125 deposition, retention, and dosimetry of inhaled radioactive substances

NCRP REPORT No 125 DEPOSITION, RETENTION AND DOSIMETRY OF INHALED RADIOACTIVE SUBSTANCES Recommendations of the NATIONAL COUNCIL ON RADIATION PRO'TEC'TION AND MEASUREMENTS Issued February 14, 1997 National Council on Radiation Protection and Measurements 7910 Woodmont Avenue I Bethesda, MD 20814-3095 LEGAL NOTICE This report was prepared by t h e National Council on Radiation Protection and Measurements (NCRP).The Council strives to provide accurate, complete and useful information in its reports However, neither the NCRP, the members of NCRP, other persons contributing to or assisting in the preparation of this report, nor any person acting on the behalf of any of these parties: (a) makes any warranty or representation, express or implied, with respect to the accuracy, completeness or usefulness of the information contained in this report, or that the use of any information, method or process disclosed in this report may not infringe on privately owned rights; or (b) assumes any liability with respect to the use of, or for damages resulting from the use of any information, method or process disclosed in this report, under the Civil Rights Act of 1964, Section 701 et seq as amended 42 U.S.C Section 2000e et seq (Title VZZ) or any other statutory or common law theory governing liability Library of Congress Cataloging-in-Publication Data National Council on Radiation Protection and Measurements Deposition, retention, and dosimetry of inhaled radioactive substances : recommendations of the National Council on Radiation Protection & Measurements p cm - (NCRP report ; no 125) "Issued February 1997 Includes bibliographical references and index ISBN 0-929600-541 Aerosols, Radioactive-Toxicology Radiation dosimetry I Title 11 Series RA1231.R2N28 1997 96-37944 CIP 612'.01448-dc21 Copyright Q National Council on Radiation Protection and Measurements 1997 All rights reserved This publication is protected by copyright No part of this publication may be reproduced in any form or by any means, including photocopying, or utilized by any information storage and retrieval system without written permission from the copyright owner, except for brief quotation in critical articles or reviews Preface The development of a respiratory tract model which accurately reflects reality is a difficult and complicated effort This stems largely from the variety of airway shapes, airflow patterns, and cell types having different radiosensitivities Anatomic and physiologic alterations in smokers or those exposed to chemicals, among others, further complicate modeling In spite of the inherent difficulties, the continuing pursuit of a model that mimics actual conditions has been considered to be important by those involved in radiation protection Recently, the International Commission on Radiation Protection published a report on the respiratory tract, ICRP Publication 66 (ICRP, 1994) While the ICRP model arrives a t similar results t o the NCRP model in most instances, quite different results are obtained for certain radionuclides Given the considerableuncertainties involved in the calculations for both models and in order to avoid confhsion in the radiation protection community as to which model to use, the NCRP recommends the adoption of ICRP Publication 66 (ICRP, 1994)for calculating exposures for radiation workers and the public, e.g., for computing annual reference levels of intake and derived reference air concentrations for workers, and arriving at values of dose per unit intake for workers and members of the public However, given the considerable uncertainties involved in modeling the respiratory tract, the NCRP believes that the present alternate model is a significant contribution to the radiation protection field and will be useful to many This Eeport was prepared by Scientific Committee 57-2 on Respiratory Tract Dosimetry Modeling Serving on Scientific Committee 57-2 were: Richard G Cuddihy, Chairman Albuquerque, New Mexico Members Gerald L Fisher Wyeth-Ayerst Research Princeton, New Jersey Robert F Phalen University of California Irvine, California iv PREFACE George M Kanapilly* Inhalation Toxicology Research Institute Albuquerque, New Mexico Richard B Schlesinger New York University Medical Center New York, New York Owen R Moss Chemical Industry Institute of Toxicology Research Triangle Park, North Carolina David L Swift Johns Hopkins School of Hygiene and Public Health Baltimore, Maryland Hsu-Chi Yeh Inhalation Toxicology Research Institute Albuquerque, New Mexico Consultants I-Yiin Chang Inhalation Toxicology Research Institute Albuquerque, New Mexico Morton Lippmann New York University New York, New York Keith F Eckerman Oak Ridge National Laboratory Oak Ridge, Tennessee Fritz A Seiler International Technology Corporation Albuquerque, New Mexico William C Griffith Inhalation Toxicology Research Institute Albuquerque, New Mexico Samuel E Walker Raton, New Mexico NCRP Secretariat Thomas M Koval, Senior Staff Scientist (1993-1997) E Ivan White, Senior Staff Scientist (1982-1993) Cindy L O'Brien, Editorial Assistant The Council wishes to express its appreciation to the Committee members for the time and effort devoted to the preparation of this Report Charles B Meinhold President, NCRP Contents Preface iii Introduction 1.1 Purpose 2 1.2 Scope 1.3 Description of this Report Anatomy and Morphometry of the Human Respiratory Tract 2.1 Anatomy of the Respiratory Tract 2.1.1 Naso-Oro-Pharyngo-LaryngealRegion 2.1.2 Tracheobronchial Region 2.1.3 Pulmonary Region 2.1.4 Thoracic Lymphatic System 2.1.5 Innervation of the Respiratory System 2.1.6 Cells a t Risk 2.2 Morphometry of Respiratory Tract Airways 2.2.1 Naso-Oro-Pharyngo-Laryngeal Region 2.2.2 Tracheobronchial Region 2.2.3 Pulmonary Region Physiology of the Respiratory Tract 3.1 Ventilation 3.1.1 Normal Parameters 3.1.2 Changes in Ventilation with Physical Activity 3.1.3 Effects of Aging 3.1.4 Other Factors 3.2 Clearance 3.2.1 Naso-Oro-Pharyngo-LaryngealRegion 3.2.2 Tracheobronchial Region 3.2.3 Pulmonary Region Factors Affecting Normal Respiratory Tract Structure and Function 4.1 Tobacco Smoke and Other Irritants 4.2 Disease 4.3 Miscellaneous Factors 4.4 Modeling Assumptions Deposition of Inhaled Substances 5.1 Particles 5.1.1 Particle Size Definitions vi / CONTENTS Particle Inhalability Deposition Mechanisms Inhaled Particle Deposition Models Naso-Oro-Pharyngo-Laryngeal Deposition Tracheobronchial and Pulmonary Deposition Regional Deposition of Inhaled Particles 5.2 Gases and Vapors 5.2.1 Gas-Phase Transport Mechanisms 5.2.2 Gas-Phase Transport and Conditions a t the Phase Boundary 5.2.3 Gas Transport on the Liquid Side ofthe Interface 5.2.4 Gas Deposition in the Naso-Oro-PharyngoLaryngeal Region 5.2.5 Gas Deposition in the Tracheobronchial and Pulmonary Regions 5.2.6 Predicted Deposition of Specific Radioactive Gases Respiratory Tract Clearance 6.1 Concepts of Respiratory Tract Clearance 6.2 Mechanical Clearance of Particles 6.2.1 Particle Clearance in the Naso-Oro-PharyngoLaryngeal Airways 6.2.2 Particle Clearance in Tracheobronchial Airways 6.2.3 Particle Clearance in the Pulmonary Region 6.2.4 Particle Clearance to Pulmonary Lymph Nodes 6.3 Absorption into the Blood 6.4 Comparison of Clearance Model Projections with Experimental Measurements Lung Model for Exposure to Radioactive Particles 7.1 Deposition 7.1.1 Naso-Oro-Pharyngo-Laryngeal Airways 7.1.2 Tracheobronchial Tree and Pulmonary Region 7.2 Clearance 7.2.1 Model Characteristics 7.2.2 Clearance Functions M(t) and A(t) 7.2.3 System of Differential Equations 7.3 Dose Calculations 7.3.1 Absorbed Dose from Photons, Electrons and Alphas 7.3.1.1 Estimating Dose from Photon-Emitting Radiation 7.3.1.2 Estimating Dose from Alpha Radiation 7.3.1.3 Estimating Dose from Beta Radiation 7.3.2 Sample Calculations of Dose 5.1.2 5.1.3 5.1.4 5.1.5 5.1.6 5.1.7 CONTENTS ~ i i 7.3.3 Modifying Factors 140 7.3.3.1 Influence of Age 140 7.3.3.2 Effect of Tobacco Smoking 142 7.3.3.3 Effect of Disease States 142 Consideration for Nonradioactive Substances 143 8.1 Deposition of Inhaled Chemical Toxicants 143 8.2 Respiratory Tract Clearance of Chemical Toxicants 144 8.3 Chemical Dose to Cells at Risk 146 Summary 150 9.1 Anatomy and Morphometry of the Respiratory Tract 150 9.2 Cells at Risk from Inhaled Radioactive Aerosols 152 9.3 Physiological Factors Related to Deposition and Clearance 153 9.4 Regional Deposition of Inhaled Particles 154 9.5 Regional Solubility of Inhaled Gases and Vapors 155 9.6 Respiratory Tract Clearance of Particles 156 9.7 Calculation of Dose from Inhaled Radionuclides 158 9.8 Chemically Toxic Inhaled Substances 159 Appendix A Clearance Data 161 A1 Manganese 162 k Cobalt 164 A Yttrium 166 A Niobium 167 A Ruthenium 170 A Cesium 172 A Barium 175 A Lanthanum 178 A Cerium 180 A10 Polonium 182 All Uranium .183 A12 Plutonium 186 A13 Americium 188 A14 Curium 190 Glossary 192 References 200 The NCRP 226 NCRP Publications 234 Index 246 Introduction The respiratory tract is a complex system characterized by a number of unique features related to airway shapes and airflow patterns with a variety of cell types with differing radiosensitivities In addition, there are anatomic and physiologic alterations in individuals who smoke or are exposed to chemical irritants, or have other special attributes Therefore, the prediction of regional deposition and retention of inhaled radioactive particles, gases and vapors in the human respiratory system, the dosimetry involved, and the determination of the impact are far from straightforward It follows, then, that the development of a realistic respiratory tract model is a difficult and extremely complicated task Both the National Council on Radiation Protection and Measurements (NCRP) and the International Commission on Radiological Protection (ICRP) have been able to take advantage of work in this area that is at the forefront of studies concerned with the respiratory tract The recently published ICRP report on this topic, ICRP Publication 66 (ICRP, 1994), and the present NCRP report have arrived at remarkably similar mathematical assessments, in general, although detailed calculations for specific radionuclides can be quite different in terms of the way they are handled For example, the ICRP principally uses the model of Egan et al (1989), whereas the NCRP uses the model of Yeh and Schum (1980) for deposition, and the ICRP and NCRP use quite different models for respiratory clearance The ICRP and NCRP models are both applicable for simulation of exposure cases for individuals and populations In order to ensure a uniform course of action providing a coherent and consistent international approach to radiation protection, the NCRP adopts the recommendations of ICRP Publication 66 on the human respiratory tract (ICRP, 1994) for calculating exposures for radiation workers and the public, e.g., for computing annual reference levels of intake and derived reference air concentrations for workers, and arriving at values of dose per unit intake for workers and members of the public The present NCRP report does not specifically address these issues, but rather focuses on fundamental considerations of human respiratory tract structure and function in deriving an alternate mathematical model to describe the deposition, clearance and dosimetry of inhaled radioactive substances For / INTRODUCTION example, this Report incorporates a multigenerational airway approach to modeling the lung while the ICRP publication uses a multicompartment model for clearance and dosimetry The ICRP model also incorporates a slow clearance component for material deposited in the bronchial and bronchiolar regions while the NCRP will await further verification of this phenomenon before incorporating it Considering the degree of uncertainty associated with modeling the respiratory system, the NCRP believes that such an alternate presentation a t this time can present a significant contribution to the development of the field of radiation protection and supplements the ICRP publication by enhancing the confidence in the results of calculating doses from t.he intake of airborne radionuclides 1.1 Purpose This Report provides a summary of scientific information and mathematical models that describe respiratory tract deposition, retention and dosimetry for radioactive substances inhaled by people The treatment of deposition and retention is applicable, as well, to nonradioactive substances The result of this review is an integrated mathematical model of deposition and clearance that is suitable for calculating doses to the respiratory tract The Report provides a framework for interpreting human exposures and related bioassay measurements 1.2 Scope This Report describes the deposition, clearance and dosimetry of inhaled substances in the respiratory tract It can be used by scientists, and others concerned with the effects of inhaled radioactive and chemically toxic substances, to calculate approximate doses to the cells and tissues at risk Mathematical models described in this Report are designed to predict the most likely mean values of deposition and clearance in various regions of the respiratory tract, and variations in these patterns to be expected for individuals who may differ in size, state of health, and mode of breathing An important characteristic of these models is that they provide information on particle deposition and clearance on an airway generation-bygeneration basis This allows a user to pinpoint an airway for the purposes of estimating initial particle deposition, or dose, at any time after deposition 1.3 DESCRIPTION OF THIS REPORT / Most of the experimental data used in this Report are derived from studies with radioactive substances, but the deposition and retention models also apply to nonradioactive materials However, dosimetry concerns for chemically toxic agents may differ from those involving radiation The most frequently calculated radiation dose parameters are the time-integrated total energy deposition and energy deposition rate in tissue For inhaled chemicals, it may be important to know peak exposure concentration, duration of exposure, cytotoxicity, potential metabolic products and, possibly, other factors Three mathematical models describing the deposition and retention ofinhaled radioactive particles have been developed by the ICRP for calculating doses from the inhalation of radionuclides The first was described in ICRP Publication 2, Report of Committee I1 on Permissible Dose for Internal Radiation (ICRP, 19591, and it was used to calculate maximum permissible concentrations of radionuclides in air The second was published in 1966 by an ICRP Task Group on Lung Dynamics EGLDACRP (1966)1, but it was not officially used for developing radiation protection guidelines until 1979 when it formed the basis for calculated annual limits on intakes of inhaled radionuclides by workers (ICRP, 1979a; 197913) The TGLD model has been widely used by the scientific community during the last 30 y During this period, no major deficiencies have been noted with respect to its intended use in formulating radiation protection guidelines for workers A third ICRP human respiratory tract model for radiological protection of workers and the public has been published (ICRP, 1994) Following the successful use of the 1966 ICRP model this Report extends its application by including people other than the healthy male worker, by incorporating the results of recent scientific investigations on inhaled aerosols and by use of improved deposition and retention modeling techniques Additional scientific information is now available to improve respiratory tract dosimetry models for assessment of exposures over a broad range of applications For those cases in which detailed studies of deposition and retention are not available, default parameters may be used This Report includes information and calculations appropriate to individuals in heterogeneous populations, including males and females of different ages, smokers and people with compromised respiratory tract defenses 1.3 Description of this Report This Report is divided into nine sections Section 1is the Introduction Section contains a description of the anatomy of the NCRP PUBLICATIONS / 239 NCRP Commentaries No Title Krypton-85 in the Atmosphere-With Specific Reference to the Public Health Significance of the Proposed Controlled Release at Three Mile Island (1980) Screening Techniques for Determining Compliance with Environmental Standards-Releases of Radionuclides to the Atmosphere (1986),Revised (1989) Guidelines for the Release of Waste Water from Nuclear Facilities with Special Reference to the Public Health Significance of the Proposed Release of Treated Waste Waters at Three Mile Island (1987) Review of the Publication, Living Without Landfills (1989) Radon Exposure of the U.S Population-Status of the Problem (1991) Misadministration of Radioactive Material in MedicineScientific Background (1991) Uncertainty in NCRP Screening Models Relating to Atmospheric Transport, Deposition and Uptake by Humans (1993) Considerations Regarding the Unintended Radiation Exposure of the Embryo, Fetus or Nursing Child (1994) Advising the Public about Radiation Emergencies: A Document for Public Comment (1994) Dose Limits for Individuals Who Receive Exposure from Radionuclide Therapy Patients (1995) Radiation Exposure and High-Altitude Flight (1995) An Introduction to Eflicacy i n Diagnostic Radiology and Nuclear Medicine (Justification of Medical Radiation Exposure) (1995) A Guide for Uncertainty Analysis i n Dose and Risk Assessments Related to Environmental Contamination (1996) Proceedings of the Annual Meeting No Title Perceptions of Risk, Proceedings of the Fifteenth Annual Meeting held on March 14-15,1979(includingTaylor Lecture No 3) (1980) / NCRP PUBLICATIONS Critical Issues in Setting Radiation Dose Limits, Proceedings of the Seventeenth Annual Meeting held on April 8-9, 1981 (including Taylor Lecture No 5) (1982) R a d i a t i o n Protection and New Medical Diagnostic Approaches, Proceedings of the Eighteenth Annual Meeting held on April 6-7, 1982 (including Taylor Lecture No 6) (1983) Environmental Radioactivity, Proceedings of the Nineteenth Annual Meeting held on April 6-7,1983 (including Taylor Lecture No 7) (1983) Some Issues Important in Developing Basic Radiation Protection Recommendations, Proceedings of the Twentieth Annual Meeting held on A p d 4-5,1984 (including Taylor Lecture No 8) (1985) Radioactive Waste, Proceedings of the Wenty-first Annual Meeting held on April 3-4,1985 (includingTaylor Lecture No 9) (1986) Nonionizing Electromagnetic Radiations and Ultrasound, Proceedings of the Twenty-second Annual Meeting held on April 2-3, 1986 (including Taylor Lecture No 10) (1988) New Dosimetry at Hiroshima and Nagasaki and Its Implications for Risk Estimates, Proceedings of the Twenty-third Annual Meeting held on April 8-9, 1987 (including Taylor Lecture No 11)(1988) Radon, Proceedings of the Twenty-fourth Annual Meeting held on March 30-31, 1988 (including Taylor Lecture No 12) (1989) Radiation Protection Today-The NCRP at Sixty Years, Proceedings of t h e Twenty-fifth Annual Meeting held on April 5-6, 1989 (including Taylor Lecture No 13) (1990) Health and Ecological Implications of Radioactively Contaminated Environments, Proceedings of the Twenty-sixth Annual Meeting held on April 4-5, 1990 (including Taylor Lecture No 14) (1991) Genes, Cancer and Radiation Protection, Proceedings of the Twenty-seventh Annual Meeting held on April 3-4, 1991 (including Taylor Lecture No 15) (1992) Radiation Protection in Medicine, Proceedings of the Twentyeighth Annual Meeting held on April 1-2, 1992 (including Taylor Lecture No 16) (1993) Radiation Science and Societal Decision Making, Proceedings of the Twenty-ninth Annual Meeting held on April 7-8, 1993 (including Taylor Lecture No 17) (1994) NCRP PUBLICATIONS / 241 Lauriston S Taylor Lectures No Title The Squares of the Natural Numbers in Radiation Protection by Herbert M Parker (1977) Why be Quantitative about Radiation Risk Estimates? by Sir Edward Pochin (1978) Radiation Protection-Concepts and Trade Offs by Hymer L Friedell (1979) [Available also in Perceptions of Risk, see abovel From "Quantity of RadiationJ' and "Dose" to "Exposure" and "Absorbed DoseJ'-An Historical Review by Harold Wyckoff (1980) How Well Can We Assess Genetic Risk? Not Very by James F Crow (1981) [Available also in Critical Issues in Setting Radiation Dose Limits, see abovel Ethics, Trade-offs and Medical Radiation by Eugene L Saenger (1982) [Available also in Radiation Protection and New Medical Diagnostic Approaches, see abovel The Human Environment-Past, Present and Future by Merril Eisenbud (1983) [Available also in Environmental Radioactivity, see above] Limitation and Assessment in Radiation Protection by Harald H Rossi (1984) [Available also in Some Issues Important i n Developing Basic Radiation Protection Recommendations, see abovel Truth (and Beauty) in Radiation Measurement by John H Harley (1985) [Available also in Radioactive Waste, see abovel Biological Effects ofNon-ionizing Radiations: Cellular Properties and Interactions by Herman P Schwan (1987) [Available also i n Nonionizing Electromagnetic Radiations and Ultrasound, see abovel How to be Quantitative about Radiation Risk Estimates by Seymour Jablon (1988) [Available also in New Dosimetry at Hiroshima and Nagasaki and its Implications for Risk Estimates, see above] How Safe is Safe Enough? by Bo Lindell(1988) [Available also in Radon, see abovel Radiobiology and Radiation Protection: The Past Century and Prospects for the Future by Arthur C Upton (1989) [Available also in Radiation Protection Today, see abovel Radiation Protection and the Internal Emitter Saga by 242 / NCRP PUBLICATIONS J Newel1 Stannard (1990) [Available also in Health and Ecological Implications of Radioactively Contaminated Environments, see abovel When is a Dose Not a Dose? by Victor P Bond (1992) [Available also in Genes, Cancer and Radiation Protection, see abovel Dose and Risk in Diagnostic Radiology: How Big? How Little?by Edward W Webster (1992)[Availablealso in Radiation Protection in Medicine, see above1 Science, Radiation Protection and the NCRP by Warren K Sinclair (1993)[Available also in Radiation Science and Societal Decision Making, see abovel Mice, Myths and Men by R.J Michael Fry (1995) Symposium Proceedings No Title The Control of Exposure of the Public to Ionizing Radiation in the Event ofAccident or Attack, Proceedings of a Symposium held April 27-29, 1981 (1982) Radioactive and Mixed Waste-Risk as a Basis for Waste Classification, Proceedings of a Symposium held November 9, 1994 (1995) NCRP Statements No Title "Blood Counts, Statement of the National Committee on Radiation Protection," Radiology 63, 428 (1954) "Statements on Maximum Permissible Dose from Television Receivers and Maximum Permissible Dose to the Skin of the Whole Body," Am J Roentgenol., Radium Ther and Nucl Med 84, 152 (1960) and Radiology 75, 122 (1960) X-Ray Protection Standards for Home Television Receivers, Interim Statement of the National Council on Radiation Protection and Measurements (1968) Specification of Units of Natural Umnium and Natural Thorium, Statement of the National Council on Radiation Protection and Measurements (1973) NCRP Statement on Dose Limit for Neutrons (1980) Control of Air Emissions of Radionuclides (1984) The Probability That a Particular Malignancy May Have Been Caused by a Specified Irradiation (1992) NCRP PUBLICATIONS 243 Other Documents The following documents of the NCRP were published outside of the NCRP report, commentary and statement series: Somatic Radiation Dose for the General Population, Report of the Ad Hoc Committee of the National Council on Radiation Protection and Measurements, May 1959, Science, February 19, 1960, Vol 131, No 3399, pages 482-486 Dose Effect Modifying Factors in Radiation Protection, Report of Subcommittee M-4 (Relative Biological Effectiveness) of the National Council on Radiation Protection and Measurements, Report BNL 50073 (T-471)(1967) Brookhaven National Laboratory (National Technical Information Service Springfield, Virginia) The following documents are now superseded andlor out of print: NCRP Reports No Title X-Ray Protection (1931) [Superseded by NCRP Report No 31 Radium Protection (1934) [Superseded by NCRP Report No 41 X-Ray Protection (1936) [Superseded by NCRP Report No 61 Radium Protection (1938) [Superseded by NCRP Report No 131 Safe Handling of Radioactive Luminous Compound (1941) [Out of Print] Medical X-Ray Protection Up to Two Million Volts (1949) [Superseded by NCRP Report No 181 Safe Handling of Radioactive Isotopes (1949) [Superseded by NCRP Report No 301 Recommendations for Waste Disposal of Phosphorus-32 and Iodine-131 for Medical Users (1951) [Out of Print1 Radiological Monitoring Methods and Instruments (1952) [Superseded by NCRP Report No 571 Maximum Permissible Amounts of Radioisotopes i n the Human Body and Muximum Permissible Concentrations in Air and Water (1953) [Superseded by NCRP Report No 221 Recommendations for the Disposal of Carbon-14 Wastes (1953) [Superseded by NCRP Report No 811 244 NCRP PUBLICATIONS Protection Against Radiations from Radium, Cobalt-60 and Cesium-137 (1954) [Superseded by NCRP Report No 241 Protection Against Betatron-Synchrotron Radiations Up to 100 Million Electron Volts (1954) [Superseded by NCRP Report No 511 Safe Handling of Cadavers Containing Radioactive Isotopes (1953) [Superseded by NCRP Report No 211 Radioactive-Waste Disposal in the Ocean (1954) [Out of Print] Permissible Dose from External Sources of Ionizing Radiation (1954) including Maximum Permissible Exposures to Man, Addendum to National Bureau of Standards Handbook 59 (1958) [Superseded by NCRP Report No 391 X-Ray Protection (1955) [Superseded by NCRP Report No 261 Regulation of Radiation Exposure by Legislative Means (1955) [Out of Print] Protection Against Neutron Radiation Up to 30 Million Electron Volts (1957) [Superseded by NCRP Report No 381 Safe Handling of Bodies Containing Radioactive Isotopes (1958) [Superseded by NCRP Report No 371 Protection Against Radiations from Sealed Gamma Sources (1960) [Superseded by NCRP Reports No 33,34 and 401 Medical X-Ray Protection Up to Three Million Volts (1961) [Superseded by NCRP Reports No 33,34,35 and 361 A Manual of Radioactivity Procedures (1961) [Superseded by NCRP Report No 581 Exposure to Radiation in a n Emergency (1962) [Superseded by NCRP Report No 421 Shielding for High-Energy Electron Accelerator Installations (1964) [Superseded by NCRP Report No 511 Medical X-Ray and Gamma-Ray Protection for Energies Up to 10 MeV-Equipment Design and Use (1968) [Superseded by NCRP Report No 1021 Medical X-Ray and Gamma-Ray Protection for Energies Up to 10 MeV-Structural Shielding Design and Evaluation Handbook (1970) [Superseded by NCRP Report No 491 Basic Radiation Protection Criteria (1971) [Superseded by NCRP Report No 911 Review of the Current State ofRadiation Protection Philosophy (1975) [Superseded by NCRP Report No 911 Natural Background Radiation in the United States (1975) [Superseded by NCRP Report No 941 Radiation Protection for Medical and Allied Health Personnel (1976) [Superseded by NCRP Report No 1051 NCRP PUBLICATIONS / 245 Review ofNCRPRadiation Dose Limit for Embryo and Fetus in Occupationally-Exposed Women (1977) [Out of Printl Radiation Exposure from Consumer Products and Miscellaneous Sources (1977) [Superseded by NCRP Report No 951 A Handbook of Radioactivity Measurements Procedures, 1st ed (1978) [Superseded by NCRP Report No 58,2nd ed.1 Mammography (1980) [Out of Printl Recommendations on Limits for Exposure to Ionizing Radiation (1987) [Superseded by NCRP Report No 1161 NCRP Commentaries No Title Preliminary Evaluation of Criteria for the Disposal of Transuranic Contaminated Waste (1982) [Out of Printl NCRP Proceedings No Title Quantitative Risk in Standards Setting, Proceedings of the Sixteenth Annual Meeting held on April 2-3, 1980 [Out of Printl Index Absorbed dose (Dl 110-112, 117, 119, 137, 140 for alphas 111 for electrons 111 for photons 111 rate 112 Absorption 32, 33, 36, 41, 81, 82, 86, 96, 99, 101, 107, 111, 139 A(t) 107, 139 functions 101 mechanisms 111 to blood 81, 99 Activity (A) 104, 112 Activity median aerodynamic diameter (AMAD)53, 137 Aerodynamic (equivalent) diameter (d.,) 51 Aerodynamic resistance diameter (d,) 52 Aerosol deposition 45, 60 Aerosols 3, 50, 82 density 82 particle size 82 shape 82 Age 27, 30, 104, 137, 140 Airflow rate 104 Airway 1, 22,40, 58,66, 90 branching 66 flow patterns generations 22, 90 lumen 40 shapes walls 58 Alpha particles 110 range 110 Alpha radiation 117 dose 117 Altitude 32 Altshuler formalism 58 Alveolar 16, 28, 44,47, 93 cells 93 macrophage 47 Alveolobronchiolar junctions 40 Ameboid motion 39 Anatomical lung model 57 Anatomy of the human respiratory tract 5, 6, 21, 24, 25, 28, 32, 50 alveoli 25 alveolar ducts 25 alveolar sacs 25 bronchioles 25 dead-space 21, 24, 28, 32 upper airways Anesthesia 35 Annual reference levels Anterior nasal areas 82, 86 clearance 82 Anxiety 49 ApicaI lobe 24 Aqueous media 81 Asthma 147 Atmospheric pressure 105, 137 Atomic numbers 86 Baboons 96 Basement membrane 12 Beagle dog 34, 86, 94 Becquerel (Bq) 139 Beta radiation 119 dose 119 Bifurcation angle 58 Bioassay measurements 80 Biological half-time (TB) Blood 9, 28, 32, 33, 41, 75, 76, 81, 93, 96, 107, 144 capillary circulation 33, 93, 96 oxygenation 28 perfusing 76 transport 75 vessels 32 Body mass 28 Body size 30, 55, 104, 137 Boltzmam constant (m 67, 105 Branching angle 66, 67 INDEX Breakpoints 139 Breathing cycle (mode) 30,59, 66, 82, 139 frequency 66 mode 82 Breathing rate 30, 90, 137 patterns 90 Bronchial asthma 48 Bronchial clearance 38, 44, 46, 90 epithelium 91 mucociliary transport 44 tissue 90 Bronchiolitis 44 Bronchoconstriction 45 Brownian motion 56 Cancer (neoplasm) 14, 15, 16, 17, 147 bronchioloalveolar adenomas 15 bronchioloalveolar carcinomas 15 fibrosarcoma 16 hemangiosarcoma 17 osteosarcomas 16 squamous cell carcinoma 17 risk 15 Carbon dioxide production 30 Cell membranes 40 Cells 11, 12, 13, 15, 44, 49 basal cells 12 brush cells 13 Clara cells 12, 15 endothelial cells 13, 15 glandular mucus cells 12 goblet cells 12, 44, 49 intermediate cells 12 interstitial cells 13 K cells 13 lymphocytes 13, 49 mast cells 13 neuroepithelial bodies 13 oncocytes 13 phagocytic cells 11 secretory cells 12 serous cells 12 squamous cells 13 Type 1cells 13 Type 11cells 12, 15 / 247 Cells at risk 140 Chemical binding 82, 87, 96 structure 96 Chemical irritants 1, 2, 75, 77 reaction 77 reactivity 75 Chemically toxic substances 80, 111 Chemical composition 96 mixed 96 Cigarette smoking 16, 43, 84, 145 Ciliated epithelium 83 Clearance 32, 37, 40, 46, 81, 89, 90, 91, 96,104, 106, 144 bronchial clearance 37, 46 half-time 89, 91 long-term 144 mechanical 32 mucociliary 32 processes 32 rates 81, 96 times 90 to blood 104 Coal tar particles 144 Convection 73, 76 velocity 76 Count median diameter (CMD)53 Cunningham slip correction factor 67, 105 Cytotoxic material 41 Density 52, 59, 104, 137 Deposition of inhaled substances 50, 76 rate 76 Deposition mechanisms 55 Diesel exhaust particles 144 carbonaceous 144 Differential equations 107, 140 Diffusing capacity (COA 44 Diffusion 40, 52, 56, 60, 63, 66, 73, 76, 104, 105 coefficient 52, 63, 105 deposition mechanism 60 equivalent diameter 52 flux 73 gases 73, 76 passive 40 248 INDEX Dissolution rate 32, 41, 81, 93, 101, 139 Donkeys 45 Dose rate conversion factors 110 Dosimetry 1,45,88, 91 dose 45 dose rate 45 modeling 88, 91 Dynamic viscosity coefficient 105 Effective particle clearance velocity 87 Elastic recoil 44 Electrostatic attraction 56 Emphysema 44 Endocytosis 40, 84 Endogenous ligands 33 Energy (Eo) 112, 139 Entrance configuration 67 Epithelial surface 88 Epithelium (ciliated) 9, 18 squamous epithelium 18 Escalator 40 mucus 40 Esophagus 83 Exercise 21, 38 Exhalation 105 Expectorating 88 Expiration 59, 68 Fecal excretion 97 Fibers 56, 84 Fiberoptic bronchoscopy 35 Fibrotic reactions 147 Fick's Law of Diffusion 69 Findeisen formalism 58 First order kinetic relationships 85 Flow rate 63 Fluid 35, 73 blanket 35 mechanics 73 pooling 35 resorption 35 Flux of gas 72, 75 Free particles 41, 44 Free radicals 148 Functional residual capacity (FRC) 27,66,137 Fused aluminosilicate particles (FAP) 93 Gallium oxide 144 Gamma camera imaging 36 Gas deposition 72, 74 Gas diffusivity 72 Gas exchange 13, 28 Gas-liquid boundary 72, 73, 75 interface 75 Gas-phase transport mechanisms 72 Gas-solid boundary 73 Gas transport 9, 58, 76 Gaseous state 69 Gases 70, 76, 78, 143 concentration 75 molecules 71 uptake 78 Gastrointestinal tract 81, 90 Geometrical (real) diameter 50, 60 Geometric mean 52 Geometric standard deviation 53 Gravitational force 55 Gray (Gy) 112, 139 Guinea pigs 95 Half-life 139 Half-time 34, 81 Health status 27 Henry's Law (H) 75, 78 Hilar nodes 41 Hilum 41 Human exposures 2, 94, 96, 101, 104,148 Human health risk assessment 80 Hydrophilic molecules 40 Hygroscopicity 56 Hypopharynx 34 Impaction 58, 59, 104 parameter 59 INDEX Inertial impaction 55, 66 Inertial motion 74 Infectious pneumonia 48 Inhalability 53 Inhalation 105 Inhalation studies (humans) 93 Inhaled particles 1, 2, 21, 40, 48, 80, 81, 84, 111, 143 chemical toxicant 143 deposition 48 gases and vapors nonradioactive substances radioactive substances 1, 111 size 81 surface area 81 temperature treatment Inhaled toxic materials 31, 85 chemicals 143 irritants 47 Inspiration 59, 68 Inspiratory flow rate 54 Insoluble particles 32, 33, 90, 94, 96 chemical forms 33 Inspiratory airflow 30 Inspirability 54, 139 Interception 56 Interspecies comparison 96 Iron oxide particles 94 Isotopes 85 51Cr (Teflon) 93 54MnC12(manganese chloride) 162 54Mn02(manganese dioxide) 162 57C00(cobalt oxide) 140, 164 @ C'o304 (cobalt oxide) 164 =Sr (fused aluminosilicate particles) 93 90Sr(fused aluminosilicate particles) 93 88Y (fused aluminosilicate particles) 93 T (fused aluminosilicate particles) 166 "Nbz(V)05 (niobium oxide) 95, 168 95Nb(niobium oxalate) 16, 168 / 249 lo3Ru(mixed oxide) 170 137Cs(fused aluminosilicate particles) 172 137CsCl(cesium chloride) 86, 174 133BaS04(barium sulfate) 86, 176 133Ba(fused aluminosilicate particles) 177 140BaC12(barium chloride) 107, 140,175 l4LaCl3 (lanthanum chloride) 178 14*CeC13(cerium chloride) 86, 96, 140, 180 (fused aluminosilicate particles) 180 210PoC12(polonium chloride) 90, 182 2"U0 (uranium oxide) 90, 183 235UFf10zFz(uranium hexifluorideluranium dioxide difluoride) 183 P ~ (plutonium 02 dioxide) 186 239h02 (plutonium dioxide) 137, 140, 186 WSfi(N03)4 (plutonium nitrate) 186 239Pu (nitrate and citrate) 86 "lAmOz (americium dioxide) 101, 140, 188 24CmC13(curium chloride) 190 244Cm203 (curium dioxide) 190 244Cm(N03)3 (curium nitrate) 190 Isotropic specific absorbed fraction 112, 115, 119 cylindrical sources 119 line sources 119 planar sources 115 point sources 112 Kinetic processes 81 first order 81 Kinetic theory of gases 70 Knudsen number (K) 105 250 / INDEX Lamina propria 13 Laminar flow 66,73 Larynx 8, 57, 77, 88 Lavaging 44 Lipophilicity 144 Liquid layer 76 Liver tumors 147 Log-!ogistic functions 59, 105 Lognormal distribution function 52 Long-term retention 91, 101 Lung 9, 22, 31, 32, 46, 66, 78, 80, 82, 96,104, 137,139, 144 clearance 96 disease 32 fluids 82 function 31 mass 139 mechanics 46 models 22, 66, 104, 137, 139 tissue 144 volume 66 ventilation 78 Lung cancer 16, 44 lifetime risk 44 Lymphatic nodes 40, 97, 107 system 40, 107 Lymphocytes 44 Lymphoid tissue 7, 11, 32, 41, 81, 84,107, 111 hilar area 11 cells 11 nodes 11, 81,107 pleura 11 vessels 32, 41, 84 Lysosomal vacuoles 147 Macrophage 39, 44,147 Macrophage transport 33 Magnetic resonance (MR) 18 cross-section 18 Magnetic resonance imaging (MRI) 18 Mass median diameter (MMD) 53 Mass stopping power 112 Mass transfer coefficient 74 Mathematical models 58, 85, 93 function 93 Maximum path length in tissues 119 Mean free path of air molecules 52, 105 Mechanical clearance 82, 85, 96, 107, 111, 139 M(t) 107, 139 for children 111 of particles 85 Mechanical processes 33, 47 clearance rate 47 Medical Internal Radiation Dose (MIRD) Committee 111 Mice 37, 94 Michaelis-Menton type kinetic 148 Model formulation 101 Molecular diffusion 73, 76 Molecular mass 79 Monodisperse aerosols 89, 90, 96 Morphometry of the human respiratory tract 5, 17, 22, 106 Type I cells Type I1 cells macrophage Mouth 5,6, 31,57, 68, 104 breathing 5, 31, 68, 104 Mucociliary clearance 37, 39, 47, 104 function 37 mechanisms 92 transport 39 transport velocities 104 Mucosa Mucus 9, 18, 33, 34, 35, 37, 39, 46, 76, 84, 88, 89 blanket 39 flow patterns 84, 88 glands layer 34 secreting cells 76 thickness 89 transport 46 velocity 33, 37 Mucus-secreting epithelium 6, 7, ciliated goblet cells Multiexponential function 42 Nasal absorption 86 Nasal airways 6, 15, 18, 20, 30, 33, 77, 86 cavity 15 passages 33, 77, 86 valve 20 Nasal breathing 68 Nasal deposition 59, 105 efficiency 59 Nasal hair 56 Nasal mucociliary transport 47, 86, 87 Nasal vestibule 86 turbinate 87 Nasal tumors 84, 87 cancers 87 Naso-oro-pharyngo-laryngeal region (NOPL) 5-8, 18, 28, 33, 49, 57, 63, 77, 85, 104, 111 nasal cilia upper airways Nasopharynx 7,33,57 Nervous system 11,12 Nitrogen oxide 76, 77 dioxide 76, 77 Nitropyrene 144 Nonradioactive materials 16, 43, 44, 47,143, 147 Benzo(a)pyrene (BaP) 143 leather 16 nickel 16 nitrogen dioxide 43 organic compounds 16 petroleum 16 sulfur dioxide 43, 44 vinyl chloride 43, 147 wood dust 16, 47 Nose 5, 6, 7, 18, 57, 60, 85, 104 breathing 5, 60, 104 nasal hairs nasal valves nostrils 6, 18, 85 septum turbinate vestibular area Obstacles 35 Olfactory region 7, 18 Oral breathing 63, 139 Oral deposition 59 efficiency 59 Oral passage 21, 83, 87 cavity 83 lips, jaw, tongue, palate 21 Organic compounds 77, 78 acetone, formaldehyde, acrolein, etc 77 krypton, radon, xenon, iodine, ruthenium tetroxide, uranium hexafluoride 78, 79 Oronasal breathing Oropharynx 7, 35, 57 Ozone (0,)76 Particle deposition 44, 57 Partial pressure 75 of gas 75 Particle radius 56 Particles 32, 34, 43, 47, 50, 88, 92, 95, 96, 104, 137 clearance 47, 88, 92, 95 clearance efficiency 43 clearance velocity 34 density 104 deposition 47 diameter 104, 137 dissolution 96 insoluble 32 loading 40, 43 soluble 32 Particles size 32, 36, 37, 50, 90, 101 activity median aerodynamic diameter (AMAD) 32 aerodynamic diameter (AD) 36 mass median aerodynamic diameter (MMAD) 37 Particle transport 58, 90 clearance velocity 90 252 INDEX Passive diffusion 71 Pause 63, 68, 137 Peclet number 73 Phagocytic cells 43 vessels 33 Phagocytosis 37, 84, 147 Pharynx 6, 77, 106 Pharyngeal clearance 88 Pharmacologic agents 49 Photon-emitting radiation 115 Pharmacokinetics 149 Physical activity 27, 30 exertion 60 Physicochemical from 81 Physiology 27, 44, 50 breathing frequency 27 functional residual capacity (FRC) 27 tidal volume 27 ventilation 27 Pinocytosis 84 Plastic dust 46 Pleural cavity 111 Pneumoconioses 48 Polystyrene particles 94 Posterior nasal airways 83, 86 region 86 Pressure drop 63 Projected area diameter 51 Proteolytic enzymes 44 Pulmonary clearance 47, 93 Pulmonary deposition 22 Pulmonary fibrosis 48 Pulmonary interstitium 40 Pulmonary (P) region 9, 10, 25, 28, 38, 57, 66, 78, 84, 92, 93, 97, 104,111, 115 acinus branches alveolar sac 10 alveoli bronchioles cavity 115 macrophage 93 surfactant terminals bronchioles Rabbits 37, 89 Radiation 1, 3, 80, 110-113, 139 annual limits on intake charged particles 110 dose 80 guidelines for workers high-LET 110 low-LET 111 photons (gamma rays) 110 protection type 139 workers yield 139 Radioactive gases 72 Radioactive particles 35, 53, 80, 96, 104,144 inhaled 80, 144 specific activity 96 Radionuclides barium (Ba) 37 radon (Rn) (progeny) 16 uranium (U) 16 Radiosensitivities Rats 37, 86, 91, 94, 144, 148 Respiratory gas volume 27 expiratory reserve volume 27 functional residual capacity 27 inspiratory capacity 27 reserve volume 27 tidal volume 27 total lung capacity 27 vital capacity 27 Respiratory parameters 82 breathing frequency 82 residual air volume 82 Respiratory tract 1, 2, 3, 13, 30, 32,43, 68, 69, 70, 72, 73, 75, 76, 80, 81, 82, 84,96, 97, 144 bronchial region bronchiolar region 2, 13 clearance 2, 32, 80, 82, 144 decay 97 deposition 1, 2, 68, 69, 70 dosimetry 2, 3, 97 mathematical models pause 30 perfusion 32 retention 1, secretion 75 tissues INDEX Respiratory tract model 1, 3, 83 default parameters Resting minute ventilation 140 Sedimentation 55, 58, 66, 104 Silicone rubber cast 22 Simulation language 140 Siip correction factor 52 Smoking humans 32, 36,44, 90 nonsmoking humans 36,44 Soluble particles 32, 96 isotopes 86 materials 80 Specific absorbed fractions 111, 112, 113, 115, 116, 117, 119, 120-136 Spherical particle 50 Squamous epithelium 6, 7, 34 Stokes' diameter 51, 67 number 67 Sulfur dioxide (SO.,) 77 Surface area 96 Surface area median diameter (SAMD) 53 Surface tension gradients 39 Surfactant 12 Swallowing 88, 106 Syrian hamsters 86 Systemic absorption 81,93 circulation 93 Task Group on Lung Dynamics (TGLD) 82 Taulbee-Yu formalism 58 Teflon discs 35, 37, 89, 94 particles 89, 94 Temperature 49, 96, 105 treatment 96 Terminal settling velocity 52 Thoracic radioactivity 10, 97, 101 lymphatic system 10 retention 101 Tidal air 66 Tidal volume 63, 68, 128 Tissues a t risk 85, 111 Tobacco smoke 43, 142 / 253 Tomography 17 Total lung capacity (TLC) 27 66 Trachea 7, 21, 35, 63, 88 Tracheobronchial (TB) region 8, 21, 28, 34, 45, 49, 57, 66, 78, 84, 88, 90, 97, 104, 111 c-shaped cartilages carina smooth muscle terminal bronchioles 8, 21 thoracic cavity Transfer rate constants 95 Tube branching 66 Turbinate 20 inferior 20 medial 20 Turbulent flow 67, 72 Typical airway length 90 Typical Path Lung Model (TPLM) 22, 106 Ultrafine particles 60, 66, 72, 77, 104,137 aerosols 77 Unit density sphere 52,68 Uranium miners 16 Urinary excretion 93 Vapor-liquid partitioning 70 Vapors 70, 143 Velocity 20 airflow 20 Ventilation 30 Vital capacity 31 Vocal cords 34 Volume equivalent diameter 52 Water solubility 75, 78 Wind 54 direction 54 speed 54 tunnels 54 Xenobiotic agents 149 Yield per disintegration 112 ... of Congress Cataloging-in-Publication Data National Council on Radiation Protection and Measurements Deposition, retention, and dosimetry of inhaled radioactive substances : recommendations of. .. deposition, retention and dosimetry for radioactive substances inhaled by people The treatment of deposition and retention is applicable, as well, to nonradioactive substances The result of this review... This Report describes the deposition, clearance and dosimetry of inhaled substances in the respiratory tract It can be used by scientists, and others concerned with the effects of inhaled radioactive