Document jmobNvjNejMdOzwX9MjGNZVQ5

FILE NAME: RT Vanderbilt (RTV) DATE: 2006 DOC#: RTV 120 DOCUMENT DESCRIPTION: Report from the Institute of Medicine of the National Academies - Asbestos-Selected Cancers A sbestos: S elected C ancers http ://w vw .nap.ed u/catato gn 1685.htm l ASBESTOS SELECTED CDtlCERS Committee on Asbestos: Selected Healtfi Effects Board on Population Health and Public Health Practices IN STITU TE O F M E D IC IN E OF THENATIONALACADEMES TEC NATIONAL ACADEMIES PRESS W ashington, D .C . www.nap.edu Copyright N ational A cadem y o f Sciences. A ll rights reserved. WES001824 Asbestos: S elected C ancers http:ZAMww.nap.edU/ratatog/l 1665.htm l THE NATIONAL ACADEMIES PRESS 500 Pifth Street, NW Washington, DC 20001 NOTICE: The project that is the subject of this report was approved by the Govern ing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineer ing, and the Institute o f Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropri ate balance. This study was supported by Contract NOl-OD-4-2139 between the National Acad emy of Sciences and the National Institutes of Health. Any opinions, findings, conclusions, or recommendations expressed in this publication are those o f the author(s) and do n o t necessarily reflect the view of the organizations o r agencies that provided support for this project. International Standard Book Number 0-309-10169-7 (Book) International Standard Book Number 0-309-65952-3 (PDF) Library of Congress Control Number: 2006928950 Additional copies o f this report are available from the National Academics Press, 500 Fifth Street, NW, Lockbox 285, Washington, DC 20055; (800) 624-6242 or (202) 334-3313 (in the Washington metropolitan area); Internet, http^/wvvw. nap.edu. For more information about the Institute of Medicine, visit the IOM home page at: www.iom.edu, Copyright 2006 by the National Academy of Sciences. All rights reserved. Printed in the United States of America. The serpent has been a symbol of long life, healing, and knowledge among almost all cultures and religions since the beginning of recorded history. The serpent adopted as a logotype by the Institute of Medicine is a relief carving from ancient ' Greece, now held by the Staatliche Musecn in Berlin. Copyright N ational A cadem y o f Sciences. A ll rights reserved. Asbestos: S e le c ted C an cers h ttp ://w vim .nap.edii/catato g/1 I6 6 5 .h tm l "Knowing is not enough; we m ust apply. W illing is not enough; we must do." -- Goethe INSTITUTE O F M EDICINE OF THE NATIONAL ACADEMIES Advising the Nation. Improving Health. , C opyright N ational A cadem y of Sciences. AH rights reserved. W ES001826 Asbestos: S elected C ancers htip i/A w w .n ap .o d u /catalo g /l 1665.htm l THE NATIONAL ACADEMIES Advherstoik NationonSciolte, Engineering, endMedicine The National Academy of Sciences is a private, nonprofit, self-perpetuating society o f distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance o f science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Acad emy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Ratph J. Cicerone is president of the National Academy of Sciences. The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engi neers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineer ing programs aimed a t meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. Wm. A. Wulf is presi dent of the National Academy of Engineering. The Institute of Medicine %va$ established in 1970 by the National 'Academy of Sciences to secure the services of eminent members o f appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Harvey V. Fineberg is president o f the Institute o f Medicine, ' The N ational Research Council was organized by the National Academy o f Sciences in 1916 to associate the broad community of science and technology with the Academy's purposes of furthering knowledge and advising the federal government. Functioning in accordance with generai policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Coun cil is administered jointly by both Academies and the Institute of Medicine. Dr. Ralph J. Cicerone and Dr. Wm. A. \Vu!fare chair and vice chair, respectively, of the National Research Council. www.national-acodemles.org C opyrigh t N ational A cadem y o f S ciences. All rights reserved. Asbestos: S elected C ancers http:ZAvwvv.nap.edu /catalog /116$5Jitm l COMMITTEE O N ASBESTOS: SELECTED HEALTH EFFECTS Jonathan M . Samet, M.D., M.S. (Chair), Professor and Chairman, Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland Lonnie R. Bristow, M.D., Private Practice and Former President of American Medical Association, Walnut Creek, California Harvey Checkoway, Ph.D., M.P.H., Professor, Department of . Environmental and Occupational Health Sciences, University of Washington, Seattle Paul Demers, Ph.D., M.Sc., Associate Professor, Department of Health Care and Epidemiology, University of British of Columbia, Vancouver Ellen A. Eiscn, M.S., Sc.D., Adjunct Professor, Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts George D. Guthrie, Jr., Ph.D., M.A., Geology and Chemistry Group, Los Alamos National Laboratory, Los Alamos, New Mexico Rogenc F. Henderson, Ph.D., D.A.B.T., Senior Scientist, Lovelace Respiratory Research Institute, Albuquerque, New Mexico Joseph W. Hogan, Sc.D., Associate Professor, Biostatistics Section and Center for Statistical Sciences Department of Community Health, Brown University, Providence, Rhode Island Agnes B. Kane, M .D., Ph.D,, Professor, Departmcnt.of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island Fadlo R. Khtiri, M.D., Professor, Winship Capcer Institute, Emory University School of Medicine, Atlanta, Georgia Roberta B. Ness, M .D., M.P.H., Chair and Professor, Department of Epidemiology, University of Pittsburgh, Pennsylvania Michael J. Thun, M .D., M.S., Vice President, Epidemiology and Surveillance Research, American Cancer Society, Atlanta, Georgia Assistants with Graphical Data Li Su, Graduate Research Assistant in Biostatistics, Department of Community Health, Brown University Yunxia Sui, Graduate Research Assistant in Biostatistics, Department of Community Health, Brown University Staff M ary Burr Paxton, Study Director Rose M arie Martinez, Director, Board on Population Health and Public Health Practice V C opyright N ational A cadem y o f S ciences. AH rights reserved. Asbestos: S elected C ancers http ://w vw .nap.ed U /catatog/t 1665.htm t Michael Schneider, Senior Program Associate T ia S. Carter, Senior Program Assistant Norman Grossblatt, Senior Editor V! Copyright National Academy of Sciences. Aft rights reserved. W ES001829 Asbestos: S elected C ancere h ttp 'iA m v.nap.ed u/catalog/11665.htm l Reviewers This report has been reviewed in draft form by persons chosen for their diverse perspectives and technical expertise in accordance with procedures approved by the National Research Council's Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the institution in making its published report as sound as possible and to ensure that the report meets institutional stan dards of objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We wish to thank the following for their review of this report: John C. Bailar, Professor Emeritus, University of Chicago, Illinois Peter R. Buseck, Professor, Department of Geological Sciences and Department of Chemistry and Biochemistry, Arizona State University, Phoenix Robert G. Coleman, Professor Emeritus, Stanford University, Atherton, California Arthur Frank, Professor and Chair, Department of Environmental and Occupational Health, School of Public Health, Drexel University, Philadelphia, Pennsylvania . Robert R Herrick, Lecture^ Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts Karl T. Kelsey, Professor, Departments of Cancer Cell Biology and Environmental Health, Harvard School of Public Health, Boston, Massachusetts vii Copyright N ational A cadem y o f Sciences. AH rights reserved. Asbestos: S elected C ancers bttpy/vww.nap.edci/cataloc/i 1 6S5.html . . Viii REVIEWERS Alfred I. Neugut, Program Director, Cancer Epidemiology and Control, Division of Epidemiology, Mailman School of Public Health, Columbia University, New York H . Catherine Skinner, Research Affiliate and Lecturer, Department of Geology and Geophysics, Yale University, New Haven, Connecticut M ark Utell, Professor, Departments of Medicine and of Environmental Medicine and Critical Care Division, University of Rochester, New York Gerald van Belle, Professor, Department of Environmental and Occupational Health Sciences, University of Washington, Seattle David Wegman, Dean, Health and Environment, University of Massachnsetts, Lowell N o d S. Weiss, Professor, Department of Epidemiology, University of Washington, Seattle Although the reviewers listed above have provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations nor did they see the final draft of the report before its release. The review of this report was overseen by Paul D. Stoliey, Univer sity of M aryland, School of Medicine, Baltimore, and by Edward B. Perrin, University of Washington, Seattle. Appointed by the National Research Council and Institute o f Medicine, they were responsible for making certain that an independent examination of this report was carried out in accor dance with institutional procedures and that all review comments were care fully considered. Responsibility for the final content of this report rests entirely with the authoring committee and the institution. C opyright N ational A cadem y o l Sciences. A ll rights reserved. WES001831 Asbestos: S elected C ancers hllp^/w vw .rap.edu/calalog/11 665.htm l Contents SUMMARY 1 1 Introduction 13 Statement of Charge, 13 Current Legislation, 13 Overview of Patterns of Asbestos Use and Recognition of Its Health Consequences, 14 Committee's Approach to Its Charge, 16 References, 17 2 Committee's Approach to Its Charge and Methods Used, in Evaluation 18 General Approach to Evidence Review, 18 Evidence Considered, 22 Criteria for Evidence Evaluation, 25 Methods Used for Quantitative Meta-Analysis, 36 Integration of Data, 43 References, 45 3 Background Information on Asbestos 49 Introduction, 49 . "Fibrous" and "Asbestiform," 50 Serpentine Asbestos (Chrysotile) Mineralogy, 52 Amphtbole Asbestos Mineralogy, 55 Properties of Potentially Hazardous Fibrous Minerals, 57 References, 61 X Copyright N ational Academ y o ( S ciences, A ll rights reserved. W ES001832 Asbestos: S elected C ancers h ttp ^/vw w jiap .ed u lcatak)g /11665.htm l X CONTENTS 4 Exposure and Disposition 63 Exposure, 63 Dosimetry, 69 References, 77 5 Biological Aspects of Asbestos-Related Diseases 81 Asbestos-Related Pulmonary Diseases and Their Mechanisms, 81 Information from Animat Studies, 90 Biomarkers, 94 References, 96 6 Description of Epidemiologic Studies Included in Evidentiary Dataset 104 Cohort Studies, 104 Case-Control Studies, 140 Integration of Epidemiologic Evidence with Non-Epidemiologic Evidence, 144 References, 145 7 Pharyngeal Cancer and Asbestos 159 Nature of This Cancer Type, 159 Epidemiologic Evidence Considered, 161 Evidence Integration and' Conclusion, 169 References, 170 ' 8 Laryngeal Cancer and Asbestos 173 Nature of This Cancer Type, 173 Epidemiologic Evidence Considered, 175 Evidence Integration and Conclusion, 186 References, 188 9 Esophageal Cancer and Asbestos 193 Nature of This Cancer Type, 193 Epidemiologic Evidence Considered, 195 Evidence Integration and Conclusion, 198 References, 200 10 Stomach Cancer and Asbestos 203 Nature of This Cancer Type, 203 Epidemiologic Evidence Considered, 204 Evidence Integration and Conclusion, 211 References, 212 Copyright N ational A cadem y ot S ciences. A ll rights reserved. W ES001833 Asbestos: S elected C ancers httpjVwvw.nap.edu/catalogT 1I665.html CONTENTS 11 Colorectal Cancer and Asbestos Nature of This Cancer Type, 216 Epidemiologic Evidence Considered, 217 ' Evidence Integration and Conclusion, 224 References, 226 12 Summary and Recommendations Summary, 230 Recommendations, 232 APPENDIXES A Agendas of Public Meetings Held by the Committee on Asbestos: Selected Health Effects B Lineage and Design Properties of Studies on Cohorts Informative for Selected Cancers C Description o f Case-Control Studies of All Selected Cancers as Related to Exposure to Asbestos D Cohort Results Tables E Case-Control Results Tables F Initial Analyses of Available Data Concerning Cancers of the Colon and/or Rectumand Asbestos Exposure G Committee on Asbestos: Selected Health Effects xi 216 230 233 237 255 271 2 97 309 323 Copyright N ational A cadem y o f Sciences. A ll rights reserved. WES001834 Asbestos: Selected Caneis httpyMwwJiap.edu/catatog/1 J665Jitml. 3 Background Information on Asbestos INTRODUCTION Asbestos is a term applied to several mineral species when they occur in a fibrous form {asbestiform). 'When the mineral species are asbestiform, they Have the physical characteristics associated with asbestos, such as large aspect ratio of fibers, flexibility, separability and weavability of fibers, and chemical and physical durability. However, in. addition to those common properties, each asbestos mineral species has unique chemical and physical . properties that make it distinct from the others. Details about the nature and limitations of techniques used to identify and characterize asbestos f i bers will not be discussed here, but can be found in reference sources such as Spumy (1994) and Roggli et al. (1992). This chapter provides an overview of asbestos mineralogy, focusing on characteristics of asbestos fibers that are potentially relevant to carcinoge nicity. In particular, the various asbestos mineral species are described, with an emphasis on the characteristics and properties related to their unique biologic properties. Minerals are known to interact dynamically with their environment particularly when they are in contact with a fluid. Such inter actions often occur at the interface between the mineral and its environ ment, in other words, at the mineral's surface. These interactions are criti cally important in many natural environments and include such phenomena as dissolution and precipitation (which alter the fluid's composition), oxi dation and reduction of species in the fluid, sorption, and ion exchange. Each of those phenomena has a potential role in mineral-induced pathogen esis, including carcinogenesis and fibrosis, although understanding of the 49 Copyright N ational A cadem y o f S ciences. A ll righte reserved. WHS0018I8 Asbestos: S elected C ancers http://w w w .nap.edU /catatog/t 1665.htm l SO ASBESTOS relationship between mineralogic properties and pathogenesis remains in complete. The concept of mineral species is fundamental to mineralogy. A min eral species is a crystalline solid with a specific atomic structure and a spe cific chemical composition (or compositional range). The specific crystal structure and chemica(composition of each mineral species imparts a unique . set of properties, including how the species interacts physically and chemi cally with its environment. In a system paralleling that for the plant and animal kingdoms, mineral species are classified hierarchically. A mineral group is roughly equivalent to the family classification and consists of min erals with similar compositions o r structures. Minerals may also exhibit variability within a species with respect to a particular property. For ex ample, some mineral species may occur with an asbestiform habit (physical form) or a non-asbestiform habit. Those are typically not given distinct mineral-species names bnt instead are referred to as varieties of the same species; sometimes, they are given varietal names, as in the case of crocidolite, which is the asbestiform variety of the mineral species riebeckitc. Other mineral groups may have species with occasional asbestiform varieties, but the primary mineral groups for asbestos are amphibole and serpentine. Each species of these groups has a distinct crystal structure, but chemical compositions vary between species within the group. The princi pal mineral species constituting asbestos are detailed below; they include asbestiform serpentine (chrysotile) and asbestiform varieties of amphibole, such as tremoltte, actinolite, anthophyllite, grunerite, riebeckite (also known as croddolite), winchite, and richterite. Table 3.X lists the mineral species, varietal names, and mineral groups associated with the common asbestos minerals. Although the three chrysotile mineral species all have the same ideal chemical formula, these polymorphs (or polytypes) differ in the nature of the stacking relationship between successive layers, with clinochrysottle being the most abundant type (Gaines ct al. 1997). "FIBROUS" AND "ASBESTIFORM" Many minerals may occur as small particles, including particles in the respirable size range, which is less than about 10 |un in aerodynamic diam eter. O f these, some may include particles with aspect ratios (length: . diameter) of 5:1 or more, usually reflecting a characteristic of the underly ing crystal structure. For example, asbestiform amphiboles have fibers that are elongate parallel to the underlying silicate chains in the structure. Fibrous is a term applied to minerals that consist of fibers, that is, ex hibit a large aspect ratio. Although the minimal aspect ratio of a mineral fiber may be debated, for the purpose of definition observed aspect ratios in general are very large (for example, over 5:1 and sometimes over 100:1). C0yH$ht National Academy of Sciences. All rights reserved. Asbestos: S elected C ancers httpyA vw w .nap.edu/catatog/11665.litnfil BACKGROUND INFORMATION O N ASBESTOS SI TAKLE 3.1 Asbestos Minerals Mineral Group Mineral Species Asbcstiform Variety Meal Chemical Formula" Serpentine Serpentine Serpentine Araphibolc Amphlbole Amphibole Amphibote Amphibole Amphibole Amphibole Amphibole Amphibole Amphibole Clinochrysotile Orthochrysotle Parachrysotiie Riebeekite Grunerite Cumraingronite Gedritc Amhophyllite Tremolile Actinolite Richterite (Alumino)winch Ferriwinchite Chrysotile Chrysotile Cbrysotle Crocidolire Amosite Amostre Amosite Asbestiforni antbophyllite Asbestiform tremolate Asbcstiform actinoite Asbestiform richterite Asbestiform winchitc Asbestiform winchite M 3S20 5(0H)4 MgjSijOjlOHL Mg3S ip j(OH)4 NaFeJSig0 22(0H); {F eM g^O jifO H ), (MgKcJjSi.OjjfOHb {MgFe)JAI2(Si6Al2)0 22(OH!2 (MgFe)7(Si),O22(0H)j Ca1Mg,Si30 22(OH)2. CajfMgFeljSijOjjfOHJj N^CatMgFJjSijO^OHh CaMa(MgFc)4AlSis0 22{0H)2 CnNa{FeMg)4Fe3*Si80 22(0H )2 "Simplified representation of the overall stoichiometry of a mineral species. Mineral species typically have chemical modifications, such as substitutions of simitar cations and sometimes anions (common examples ate Mg^c-s-Fc** and Si4k<->AI3k). Substitutions may cause sub stantiated deviations from the ideal chemical formula. Limits of chemical variation are defined for each mineral species In Table 3.2. SOURCE: Gaines et al. (1997). Asbestiform refers to a subset of fibrous minerals. Among fibrous min erals, some exhibit the additional qualities of flexibility and separability (which contribute to weavability). Such minerals are referred to as asbes tiform. Typically, asbestiform minerals also have relatively small fiber di ameters (usually under 1 pm) and large fiber lengths (such as 5-10 pm). The asbestiform characteristics are related to properties of the underlying crys tal structures, with the specific relationship according to the mineral group. For example, it has been suggested that flexibility is related to defects in die crystal structure of the asbestiform varieties of amphibole (Veblen and Wylie 1993), whereas flexibility in asbestiform serpentine (the various forms of chtysotile) may be related to the hydrogen bonding between concentric sheets of 1:1 layers, as described below. . Some mineral species have both asbestiform and non-asbestiform vari eties, and these varieties may have properties beyond just their flexibility that differ. For example, consider the grain boundaries in asbestiform am phibole. Asbestos fibers typically occur as parallel bundles of fibrils (fila ments consisting of individual crystals) that are bound together along grain boundaries. The material along the grain boundaries typically is not am- Copyright N ational A cadem y o f S ciences. AH rights reserved. W ES001820 Asbestos: S elected C ancers . http:/A vw .nap.edu/catalog/116 6 5 b lm l - 52 ASBESTOS phibolc but rather a layer silicate, such as talc or mica. When the material is processed, fibers are produced by the breaking apart of packets of fibrils by separation along the structurally weaker grain boundaries, which allows the layer-silicate material to become the surface of the fiber. It is this crys talline material that interacts with the biologic system after inhalation or ingestion. In contrast, the surface of a non-asbestiform variety of ainphibole (either an acicular crystal or a cleavage fragment) is often amphibole (and not layer silicate) because the particles are formed either by growth of the original amphibole crystal in the case of acicular fibers or by fracture along weaker atomic planes in the amphibole structure. Hence, asbestiform amphibole is likely to have a different surface structure and composition from non-asbestiform amphibole. Those differences in surface material re sult in different surface properties between asbestiform and non-asbestiform minerals of the same species, which may in turn result in different biologic responses. Some fibrous but non-asbestiform minerals also pose potential concern with respect to human exposure. For example, the fibrous zeolite erionite has been associated with human cases of mesothelioma after environmental exposure (Baris et ah 1987). SERPENTINE ASBESTOS (CHRYSOTILE) MINERALOGY Chrysotile--sometimes called white asbestos--is the most common type of asbestos to be used commercially, accounting for about 85% of world asbestos production in 1977 (Liddell 1997, Schreier 1989). At present, chrysotile is the only type of asbestos used in manufacturing in the United States (ATSDR 2001). In addition, chrysotile and other serpentine minerals are common naturally, particularly in hydro thermally altered, magnesium-rich rocks, such as altered basalt, peridotite, and dunite. Many such rocks have been almost completely altered to serpentine and are re ferred to as serpentinites. Although lizarditc is the most common form of serpentine in these rocks, chrysotile can also be present, typically having formed as a late-stage mineral filling veins and sometimes replacing the bulk rock. Chrysotile has been commercially exploited in Canada (Quebec and Ontario), the United States (Vermont and California), Zimbabwe, Rus sia, South Africa, Australia, and elsewhere (Ross 1981), and it has been used in various products, including insulation, friction materials (such as brake pads), and fiber-reinforced composites (such as concrete) (Harrison et at. 1999, Ross and Virta 2001). In addition to synthetic ehrysotilebearing materials, natural deposits are possible sources of exposure to chrysotile, either by direct exposure to chrysotile-bcaring rocks and soils o r by redistribution o f chrysotile fibers from large natural deposits, such as occurs at Coaliiiga, California (Klein 1993). It has been argued diat atmo- Copyright National Academy of Sciences- AH righto reserved. BACKGROUND INPORMATION O N ASBESTOS S3 spheric processes have redistributed Coaiinga chrysotile over the entire Northern Hemisphere from its occurrence in soils in a 50-mi2 area (Klein 1993). Serpentine minerals belong to a family of 1;1 layer silicates, which are compos! of a sheet of polymerized SiO^4- tetrahedra (with silicon a t the center of each tetrahedron and oxygen at each apex) that is bonded to a sheet of polymerized M gfOH^4- octahedra (with magnesium at the center of each octahedron and oxygen at each apex) (Figure 3.1). This ratio of tetrahedral to octahedral sheets gives the 1:1 layer silicates their name. The FIGURE 3.1 Lizardite structure viewed down the a-axis. Polymerized silica tetrahedra form a sheet at the bottom of each 1:1 unit (two units are shown stacked vertically), and magnesium hydroxide octahedra form a sheet drawn as ball-and-srick. In chrysotile, the 1:1 units curl with the slightly smaller tetrahedral sheets to the inside, exposing an octahedral sheet to the outside o f the particle. SOURCE: Mellini (1982).