THE HEALTH CONSEQUENCES OF' SMOKING CANCER AND CHRONIC LUNG DISEASE IN THE WORKPLACE a report of the Surgeon General 1985 U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES Public Health Serwce Offlce on Smokrtg and Health RockwIle, Maryland 20857 The Honorable Thanas P. O'Neill, Jr. Speaker of the Haxx of Representatives Washington, D.C. 20515 Dear Mr. Speaker: It is a pleasure to transmit to the Congress the final edition of the Surgeon General's Report on the Health Consequences of -king, as mandated by Section 8(a) of the Public Health Cigarette Swkinq Act of 1969. This is the Public Health Service's 17th Repsrt cn this topic and, like earlier Reports. identifies cigarette smoking as one of this Nation's rmst seriws public health problems. This Reprt, tiicb provides a detailed review of the relationship between snaking and hazardous substances in the workplace, is particularly disturbing because of the added health burden that mny workers carry if they smke cigarettes. As this Report makes clear, for sane mrkers this added burden is substantial. No better example exists to illustrate this interaction than the case of asbestos wxkers. Current scientific evidence indicates that heavily exposed asbestos insulation rorkers who did not snake may expxienne a S-fold increase in lung cancer caped to making, nmexpsed uxkers. Hcw?ver, if this sanrz worker also srraked, his lurq cxcw risk is increased rrore than 5C-fold. Also disturbi- is the mntinued high rate of current cigarette use anrxq blue collar wrkers cmpred to their white collar counterparts. These wxkers are mm apt to he eqosed to dusts and other harmful substances in their wrkplace envir-nts. Prqfan-s to reduce wxkplace hazardous eqx~~res are helping to offset these risks. For the majority of rorkers who make, cigarette smking poses a greater risk to health than does cnxpaticnal exposure. Thus, elimination of cigarette smking zum!q such mrkers can have a profound effect on iiqxoving their health. This Department has a strong commitment to prevention and health pranticn. It is essential that wxkplxe health prcnnticn prcqrams have a strong fans on reducing cigarette smking mm-g enplopes to the extent possible. These efforts can not only have an effect cn the health of the individual, but may also have a substantial impact by reducing absenteeism on the job, thereby improving prcductivity ant! reduciq health care costs. Cigarette inking is associated with an estimated $23 billion in health care costs annually and wer $30 billiar in lost productivity and wages. To a certain degree we all share these cxts whether we mke or not. Prqrams that reduce smoking, therefore, can have a benefit to all cur society. Sincerely, Otis R. Bcwen, M.D. secretary Enclosure w1 1% The Honorable George Bush President of the Senate Washington, D.C. 20510 Gear Mz. President: It is a pleasure to transnit to the Congress the final edition of the Surgecm General's Report cm the Health Cmsequems of Smkirq, as rmrdated by Section 8(a) of the Public Health Cigarette Smking Act of 1969. This is the Public Health Service's 17th Reprt cm this tqic and, like earlier Reports, identifies cigarette smking as me of this Nation's mst sericus @lit health problems. This Repxt, which provides a detailed review of the relationship between smking and hazardcas substames in the wxkplace, is particularly disturbing because of the added health burden that mny workers carry if they snake cigarettes. As this Report ekes clear, for xme workers this added burden is substantial. No better example exists to illustrate this interaction than the case of asbestos hot-kers. Current scientific evidence indicates that heavily exposed asbestos insulation workers who did not m&e may experiexe a 5-fold iirrease in luq cancer canpared to ncmsmking. ncnexpxed workers. Hmever, if this same vorker also smoked. his lung cancer risk is increased mre than SC-fold. Also disturbing is the nntinued high rate of current cigarette use amrg blue collar wxkers rrrrpared to their white collar canterparts. These wxkers are rmre apt to be exposed to dusts and other harmful substances I" their wxkplace envirmuwnts. Prqram to reduce workplace hazardous exposures are helpirq to offset these risks. For the majority of mrkers who mke, cigarette srckirq poses a greater risk to health than dces occupational exposure. Thus, eliminatim of cigarette samking amng such wxkers can have a profound effect cn improving their health. This Ehzpartment has a struq mitment to prevention and health pramtim. It is essential that workplace health prmticn prqrams have a strong focus on reducing cigarette making amxq qloyees to the extent possible. These efforts can not only have an effect on the health of the individual, but my also have a substantial impact by reducing absenteeism on the job, thereby improving productivity and reducing health care costs. Cigarette sawking is assoziated with an estimated $23 billion in health care costs annually and cwer $30 billim in lost productivity and wages. To a certain degree we all share these costs ðer we mke or not. Prqram.5 that reduce mking, therefore, can have a benefit tc all cur society. Sincerely, Otis R. Sam, M.D. secretary FOREWORD Over the past generation, the actions of labor unions, manage- ment, insurers, and Government have made substantial progress in reducing exposure to hazardous substances in the workplace. This Report acknowledges this progress, and demonstrates clearly that these efforts to protect the American worker must continue. There can be no relaxation in our efforts to continue the safeguards already in place or to seek new safeguards as new hazards are identified. This Report also establishes that for these efforts to protect the worker to fully succeed, these same forces of labor, management, insurers, and Government must become equally engaged in attempts to reduce the prevalence of cigarette smoking, particularly among those working populations most at risk. For the majority of workers who smoke, cigarette smoking poses a greater risk to health than does occupational exposure. This 1985 Report of the Surgeon General examines in greater depth than ever before the relationships between cigarette smoking and occupational exposures; it is a document of singular importance. As with previous Reports, a large number of experts and scientists recruited from both within and outside the Federal service have participated in developing and reviewing the content of this Report. I express here my respect and gratitude for their efforts. Donald Ian Macdonald, M.D. Acting Assistant Secretary for Health vii PREFACE The 1985 Report on the Health Consequences of Smoking presents a comprehensive review of the interaction of cigarette smoking with occupational exposures in the production of cancer and chronic lung disease. Cigarette smoking and its relationship to cancer and chronic obstructive lung disease (COLD) were extensively reviewed in the 1982 and 1984 Surgeon General's Reports, respectively. In the 1982 Report, cigarette smoking was judged to be the leading cause of cancer mortality in the United States; a causal association was found between smoking and cancer of the lung, larynx, oral cavity, and esophagus, and smoking was identified as a contributory factor in the development of cancer of the bladder, kidney, and pancreas. In 1984, cigarette smoking was identified as the major cause of COLD, which includes chronic bronchitis and emphysema, among both men and women in the United States. The contribution of other factors in COLD morbidity and mortality was found to be far less important than that of cigarette smoking. This Report examines the evidence available on the role played by cigarette smoking and occupational exposure in the development of cancer and chronic lung disease. Cancer and chronic lung disease are major causes of death in the United States, accounting for well over 25 percent of all deaths annually. Cancer mortality rates have shown a steady increase, unlike rates for the major cardiovascular diseases, which have declined over the last two decades. Chronic lung disease, now the fifth leading cause of mortality, has been increasing more rapidly than other major causes of death. It is estimated that more than 10 million Americans report suffering from these diseases. Findings of the 1985 Report The major overall conclusions of this Report are these: For the majority of American workers who smoke, cigarette smoking represents a greater cause of death and disability than their workplace environment. In those worksites where well-established disease outcomes occur, smoking control and reduction in exposure to hazardous agents are effective, compatible, and occasionally synergistic ix approaches to the reduction of disease risk for the individual worker. Smoking and occupational exposures can interact synergistically to create more disease than the sum of the separate exposures. This kind of interaction is exemplified by the relationship between asbestos exposure and smoking. A study of heavily exposed asbestos insulation workers, more than 20 years after onset of exposure, demonstrated a fivefold increased risk for lung cancer among nonsmoking asbestos workers compared with nonsmokers without asbestos exposure. We know that in non-asbestos-exposed popula- tions, smoking increases the lung cancer risk approximately tenfold. The risk is increased more than fiftyfold if the asbestos workers also smoke. This risk in cigarette-smoking asbestos workers is greater than the sum of the risk of the independent exposures, .and is approximated by multiplying the risks of the two separate expo- sures. In other words, for those workers who both smoke and are exposed to asbestos, the risk of developing and dying from lung cancer is 5,000 percent greater than the risk for individuals who neither smoke nor are exposed. Thus, the interaction of cigarette smoking and asbestos exposure is multiplicative. For asbestos workers, the risk of developing and dying of lung cancer increases with an increasing number of cigarettes smoked per day and with an increasing asbestos exposure. For example, the risk is 87 times greater for those workers who smoke more than one pack per day. The risk declines among workers who are able to stop smoking, compared with the risk for those who continue to smoke. An interaction for the production of lung cancer also exists between cigarette smoking and the radon daughters exposure of miners, although the exact nature of this interaction is not clear. Both cigarette smoking and exposure to certain occupational hazards increase the risk for chronic lung disease. These risks can occur independently or may combine to produce a greater degree of lung injury than would have occurred from either exposure separate- ly. While many exposures are capable of producing chronic lung injury, either independently or in combination, smoking appears to be the more important exposure for the majority of U.S. workers. Differences in Smoking Behavior Between White-Collar Workers and Blue-Collar Workers This Report also presents detailed findings with regard to differ- ences in smoking prevalence between blue-collar workers and white- collar workers. Blue-collar workers are more likely to be exposed to workplace agents, which, in combination with their higher smoking rates, may place these workers at considerable excess risk for cancer X and chronic lung disease. Although these differences exist among both men and women, they are more pronounced among men. The differences in the prevalence of smoking between blue-collar workers and white-collar workers may underestimate the differences found among specific populations of occupationally exposed workers. As noted in this Report, individual studies among certain workers report current smoking rates well in excess of 50 percent. In addition, in one of the largest studies of asbestos workers, more than 80 percent of the men in the cohort had been regular cigarette smokers during their lifetime and only 11 percent were classified as never having smoked regularly. These differences in smoking behavior make the control for smoking behavior an important part of the design of studies of the relationship of occupational exposures and cancer or chronic lung disease. On the average, blue-collar men initiate smoking approximately 14 months earlier than white-collar men. We know from existing studies that an earlier age of initiation is strongly correlated with increased mortality for lung cancer and chronic lung disease as well as for most other smoking-related diseases. Even with this earlier age of initiation, a substantial fraction of blue-collar workers begin smoking coincident with their entry into the workforce, and blue- collar workers are less likely than white-collar workers to be able to successfully quit smoking. Smoking Control in the Workplace The potential role of the workplace in promoting initiation and fostering the continuation of smoking behavior represents a kind of interaction between smoking and the workplace that may affect large numbers of U.S. workers. It seems clear that the responsibility for health in the workplace includes at minimum a work environ- ment that does not promote smoking or interfere with cessation. The worksite offers an opportunity for implementation of smoking cessation programs. A number of studies cited in this Report found worksite-based programs to be more successful than clinic-based programs, probably owing to their more intensive nature and because many employer-sponsored programs offer economic and other incentives, thus enhancing their success. The goal in public health, both in the worksite and outside it, is the reduction and elimination of disease and the promotion of healthy behavior. The content of this Report makes it clear that the elimination of chronic lung disease and cancer from the workplace cannot succeed without a companion effort to alter the smoking behavior of workers. It is precisely those occupations in which the greatest occupational hazards have existed that smoking cessation also yields the greatest return for individual worker's health. It xi should be obvious that smoking cessation efforts are an adjunct to, and not a substitute for, occupational environmental controls. Correspondingly, a concern about workers' health that limits itself to the control of environmental exposure levels disregards the major health benefits of smoking cessation. C. Everett Koop, M.D. Surgeon General xii ACKNOWLEDGMENTS This Report was prepared by the U.S. Department of Health and Human Services under the general editorship of the Office on Smoking and Health, Donald R. Shopland, Acting Director. Manag- ing Editor was William R. Lynn, Acting Technical Information Officer, Office on Smoking and Health. Senior scientific editor was David M. Burns, M.D., Associate Professor of Medicine, Division of Pulmonary and Critical Care Medicine, University of California at San Diego, San Diego, Califor- nia. Consulting scientific editors were Ellen R. Gritz, Ph.D., Asso- ciate Director for Research, Division of Cancer Control, Jonsson Comprehensive Cancer Center, University of California at Los Angeles, Los Angeles, California; John H. Holbrook, M.D., Associate Professor of Internal Medicine, University of Utah Medical Center, Salt Lake City, Utah; and Jonathan M. Samet, M.D., Associate Professor of Medicine, Department of Medicine, The University of New Mexico School of Medicine, Albuquerque, New Mexico. The following individuals prepared draft chapters or portions of the Report. Victor E. Archer, M.D., Clinical Professor, Rocky Mountain Center for Occupational and Environmental Health, The University of Utah Medical Center, Salt Lake City, Utah Michael E. Baser, M.S., Chief, Occupational Health, Bureau of Environmental Epidemiology and Occupational Health, New York State Health Department, Albany, New York David M. Burns, M.D., Associate Professor of Medicine, Divisicn of Pulmonary and Critical Care Medicine, University of California at San Diego, San Diego, California David B. Coultas, M.D., Instructor of Medicine, Department of Medicine and the New Mexico Tumor Registry, The University of New Mexico School of Medicine, Albuquerque, New Mexico John E. Craighead, M.D., Professor and Chairman, Department of Pathology, The University of Vermont College of Medicine, Burlington, Vermont Lori A. Crane, M.P.H., Staff Research Associate, Division of Cancer Control, Jonsson Comprehensive Cancer Center, University of California at Los Angeles, Los Angeles, California Philip E. Enterline, Ph.D., Department of Biostatistics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsyl- vania Russell E. Glasgow, Ph.D., Research Scientist, Oregon Research Institute, Eugene, Oregon David F. Goldsmith, Ph.D., Visiting Assistant Professor, Department of Internal Medicine, School of Medicine, University of California at Davis, Davis, California Robert C. Klesges, Ph.D., Associate Professor, Center for Applied Psychological Research, Department of Psychology, Memphis State University, Memphis, Tennessee Alfred C. Marcus, Ph.D., Program Director for Evaluation, Division of Cancer Control, Jonsson Comprehensive Cancer Center, Univer- sity of California at Los Angeles, Los Angeles, California Steven Markowitz, M.D., Environmental Sciences Laboratory, De- partment of Community Medicine, The Mount Sinai Medical Center, The Mount Sinai School of Medicine of the City University of New York, New York, New York James A. Merchant, M.D., Dr.P.H., Professor of Preventive and Internal Medicine, and Director, Institute of Agricultural Medi- cine and Occupational Health, The University of Iowa College of Medicine, Iowa City, Iowa Albert Miller, M.D., Clinical Professor of Medicine (Pulmonary), Clinical Professor of Community Medicine (Environmental), and Director, Pulmonary Function Laboratory, Division of Pulmonary Medicine, Department of Internal Medicine, The Mount Sinai Medical Center, The Mount Sinai School of Medicine of the City University of New York, New York, New York Donald P. Morgan, M.D., Ph.D., Professor, Department of Preventive Medicine and Environmental Health, The University of Iowa College of Medicine, Iowa City, Iowa W.K.C. Morgan, M.D., F.R.C.P.(Edl, F.R.C.P.(C), F.A.C.P., Chest Diseases Unit, University Hospital, London, Ontario, Canada Brooke T. Mossman, Ph.D., Associate Professor of Pathology, and Chairman, Cell Biology Program, Department of Pathology, The University of Vermont College of Medicine, Burlington, Vermont Paul R. Pomrehn, Jr., M.D., Assistant Professor, Department of Preventive Medicine and Environmental Health, and Director, University Occupational Health Service, The University of Iowa College of Medicine, Iowa City, Iowa Howard E. Rockette, Ph.D., Professor of Biostatistics, Department of Biostatistics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania Jonathan M. Samet, M.D., M.S., Associate Professor of Medicine, Department of Medicine, The University of New Mexico School of Medicine, Albuquerque, New Mexico xiv Cecilia M. Smith, M.D., Assistant Professor of Medicine, Division of Pulmonary and Critical Care Medicine, University of California at San Diego, San Diego, California Melvyn S. Tockman, M.D., Ph.D., Associate Professor of Environ- mental Health Sciences, with joint appointments in Respiratory Medicine and Epidemiology, Center for Occupational and Environ- mental Health, The Johns Hopkins University, Baltimore, Mary- land Pamela H. Wolf, Dr.P.H., Biostatistician, Contraceptive Evaluation Branch, Center for Population Research, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland The editors acknowledge with gratitude the following distin- guished scientists, physicians, and others who lent their support in the development of this Report by coordinating manuscript prepara- tion, contributing critical reviews of the manuscript, or assisting in other ways. Charles A. Althafer, Assistant Director for Health Promotion and Risk Appraisal, Office of Program Planning and Evaluation, National Institute for Occupational Safety and Health, Centers for Disease Control, Atlanta, Georgia Harlan E. Amandus, Ph.D., Statistician, Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control, Morgantown, West Virginia Stephen M. Ayres, M.D., Dean, School of Medicine, Medical College of Virginia, Richmond, Virginia Mary A. Ballew, MS., Epidemiologist, Document Development Branch, Division of Standards Development and Technology Transfer, National Institute for Occupational Safety and Health, Centers for Disease Control, Cincinnati, Ohio Margaret R. Becklake, M.D., Professor, Departments of Medicine, Epidemiology, and Biostatistics, McGill University, Montreal, Quebec, Canada, on sabbatical, and Career Investigator, Medical Research Council of Canada, Montreal, Quebec, Canada, on leave; Professor (Honorary), Department of Community Health, Univer- sity of the Witwatersrand, and Principal Medical Officer, National Centre for Occupational Health, Department of Health and Welfare, Johannesburg, South Africa Kenneth R. Berger, M.D., Ph.D., Adjunct Assistant Professor, Epidemiology and Preventive Medicine, University of Maryland School of Medicine, Baltimore, Maryland Robert Bernstein, Senior Reviewer, Document Development Branch, Division of Standards Development and Technology Transfer, National Institute for Occupational Safety and Health, Centers for Disease Control, Cincinnati, Ohio xv Donald B. Bishop, Ph.D., Research Associate, Department of Psychol- ogy, Washington University in St. Louis, St. Louis, Missouri Brian A. Boehlecke, M.D., M.P.H., Associate Professor of Medicine, Division of Pulmonary Diseases, Critical Care and Occupational Medicine, Department of Medicine, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina Lester Breslow, M.D., M.P.H., Co-Director, Division of Cancer Control, Jonsson Comprehensive Cancer Center, University of California at Los Angeles, Los Angeles, California Benjamin Burrows, M.D., Professor of Internal Medicine, and Director, Division of Respiratory Sciences, The University of Arizona College of Medicine, Tucson, Arizona Robert M. Castellan, M.D., Chief, Clinical Section, Clinical Investiga- tions Branch, Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control, Morgantown, West Virginia John E. Davies, M.D., M.P.H., Professor and Chairman, Department of Epidemiology and Public Health, University of Miami School of Medicine, Miami, Florida Vincent T. DeVita, Jr., M.D., Director, National Cancer Institute, National Institutes of Health, Bethesda, Maryland John E. Diem, Ph.D., Professor of Statistics, Tulane University, New Orleans, Louisiana Manning Feinleib, M.D., Dr.P.H., Director, National Center for Health Statistics, Office of the Assistant Secretary for Health, Hyattsville, Maryland Edwin B. Fisher, Jr., Ph.D., Associate Professor of Psychology and Preventive Medicine, Department of Psychology, Washington University in St. Louis, St. Louis, Missouri Lawrence Garfinkel, M.A., Vice President for Epidemiology and Statistics, and Director of Cancer Prevention, American Cancer Society, Incorporated, New York, New York J.C. Gilson, M.D., Hembury Hill Farm, Honiton, Devon, England, United Kingdom William E. Halperin, M.D., M.P.H., Chief, Industrywide Studies Branch, Division of Surveillance Hazard Evaluations and Field Studies, National Institute for Occupational Safety and Health, Centers for Disease Control, Cincinnati, Ohio Peter V.V. Hamill, M.D., M.P.H., Adjunct Professor, Epidemiology and Preventive Medicine, University of Maryland School of Medicine, Baltimore, Maryland John L. Hankinson, Ph.D., Chief, Clinical Investigations Branch, Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control, Morgantown, West Virginia xvi Naomi Harley, Ph.D., Professor, Institute of Environmental Medi- cine, New York University Medical Center, New York, New York Wayland J. Hayes, Jr., M.D., Ph.D., Professor Emeritus of Biochemis- try (Toxicology), School of Medicine, Vanderbilt University, Nash- ville, Tennessee Ian T.T. Higgins, M.D., Professor Emeritus of Epidemiology and of Environmental and Industrial Health, School of Public Health, The University of Michigan, Ann Arbor, Michigan, and Acting Chief of Epidemiology, American Health Foundation, New York, New York Thomas K. Hodous, M.D., Medical Officer, Clinical Investigations Branch, Division of Respiratory Disease Studies, National Insti- tute for Occupational Safety and Health, Centers for Disease Control, and Adjunct Associate Professor, West Virginia Universi- ty School of Medicine, Morgantown, West Virginia Michael Jacobsen, Ph.D., Deputy Director, Institute for Occupational Medicine, Edinburgh, Scotland, United Kingdom Robert N. Jones, M.D., Professor of Medicine, Pulmonary Diseases Section, Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana Marcus M. Key, M.D., Professor of Occupational Medicine, Program in Occupational Safety and Health, School of Public Health, University of Texas Health Science Center at Houston, Houston, Texas Kaye H. Kilburn, M.D., Ralph Edgington Professor of Medicine, Laboratory for Environmental Sciences, University of Southern California School of Medicine, Los Angeles, California Arthur M. Langer, Ph.D., Associate Professor of Mineralogy, The Mount Sinai School of Medicine of the City University of New York, New York, New York N. LeRoy Lapp, M.D., Professor of Medicine, Pulmonary Disease Section, West Virginia University Medical Center, Morgantown, West Virginia Richard A. Lemen, Director, Division of Standards Development and Technology Transfer, National Institute for Occupational Safety and Health, Centers for Disease Control, Cincinnati, Ohio Claude Lenfant, M.D., Director, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland Trent R. Lewis, Ph.D., Chief, Experimental Toxicology Branch, Division of Biomedical and Behavioral Science, National Institute for Occupational Safety and Health, Centers for Disease Control, Cincinnati, Ohio Edward Lichtenstein, Ph.D., Professor of Psychology, University of Oregon, and Research Scientist, Oregon Research Institute, Eu- gene, Oregon xvii Ruth Lilis, M.D., Professor, Division of Environmental and Occupa- tional Medicine, Department of Community Medicine, The Mount Sinai School of Medicine of the City University of New York, New York, New York Jay H. Lubin, Ph.D., Health Statistician, Biostatistics Branch, Division of Cancer Etiology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland James 0. Mason, M.D., former Acting Assistant Secretary for Health, Washington, D.C., and Director, Centers for Disease Control, Atlanta, Georgia J. Corbett McDonald, M.D., F.R.C.P., Professor, School of Occupa- tional Health, McGill University, Montreal, Quebec, Canada J. Michael McGinnis, M.D., Deputy Assistant Secretary for Health (Disease Prevention and Health Promotion), Office of the Assistant Secretary for Health, Washington, D.C. J. Donald Millar, M.D., Assistant Surgeon General and Director, National Institute for Occupational Safety and Health, Centers for Disease Control, Atlanta, Georgia Anthony B. Miller, M.B., F.R.C.P.(C), Director, Epidemiology Unit, National Cancer Institute of Canada, and Professor of Preventive Medicine and Biostatistics, University of Toronto, Toronto, Ontar- io, Canada Kenneth M. Moser, M.D., Professor of Medicine, School of Medicine, University of California at San Diego, La Jolla, California, and Director, Division of Pulmonary and Critical Care Medicine, University of California Medical Center, San Diego, California Robert J. Mullan, M.D., Medical Officer, Surveillance Branch, Division of Surveillance Hazard Evaluations and Field Studies, National Institute for Occupational Safety and Health, Centers for Disease Control, Cincinnati, Ohio Muriel Newhouse, M.D., F.R.C.P., Department of Occupational Health and Applied Physiology, London School of Hygiene and Tropical Medicine, University of London, London, England, Unit- ed Kingdom William J. Nicholson, Ph.D., Associate Professor, Division of Envi- ronmental and Occupational Medicine, Department of Community Medicine, The Mount Sinai School of Medicine of the City University of New York, New York, New York Judith K. Ockene, Ph.D., Associate Professor of Medicine, and Director, Division of Preventive and Behavioral Medicine, Depart- ment of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts C. Tracy Orleans, Ph.D., Clinical Assistant Professor, University of Pennsylvania Medical School, Philadelphia, Pennsylvania; Smok- ing and Health Consultants, Incorporated, Princeton, New Jersey . . . xv111 Carl E. Ortmeyer, Ph.D., Public Health Statistician (Retired), National Institute for Occupational Safety and Health, Centers for Disease Control, Morgantown, West Virginia John M. Peters, M.D., Professor, and Director, Division of Occupa- tional Health, Department of Preventive Medicine, University of Southern California School of Medicine, Los Angeles, California Richard Peto, M.A., MSc., I.C.R.S., Requis Assessor of Medicine, Radcliffe Infirmary, University of Oxford, Oxford, England, Unit- ed Kingdom Philip C. Pratt, M.D., Professor of Pathology, Department of Pathology, Duke University Medical Center, Durham, North Carolina Edward P. Radford, M.D., Visiting Professor, University of Occupa- tional and Environmental Health, School of Medicine, Yahata Nishi-Ku, Kitakyushu, Japan Robert B. Reger, Ph.D., Chief, Epidemiological Investigations Branch, Division of Respiratory Disease Studies, National Insti- tute for Occupational Safety and Health, Centers for Disease Control, Morgantown, West Virginia Attilio D. Renzetti, Jr., M.D., Professor of Medicine, and Chief, Division of Respiratory, Critical Care, and Occupational Pulmo- nary Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah E. Neil Schachter, M.D., Professor of Medicine and Community Medicine, The Mount Sinai School of Medicine, and Director, Respiratory Therapy, The Mount Sinai Medical Center, The Mount Sinai School of Medicine of the City University of New York, New York, New York Richard S. Schilling, M.D., Department of Occupational Health and Applied Physiology, London School of Hygiene and Tropical Medicine, University of London, London, England, United King- dom Irving J. Selikoff, M.D., Professor Emeritus, The Mount Sinai School of Medicine of the City University of New York, New York, New York Kyle N. Steenland, Ph.D., Epidemiologist, Industrywide Studies Branch, Division of Surveillance Hazard Evaluations and Field Studies, National Institute for Occupational Safety and Health, Centers for Disease Control, Cincinnati, Ohio Jesse L. Steinfeld, M.D., President, Medical College of Georgia, Augusta, Georgia Arthur C. Upton, M.D., Professor, and Chairman, Institute of Environmental Medicine, New York University Medical Center, New York, New York John Christopher Wagoner, M.D., F.R.C.(Path), Medical Research Council Pneumoconiosis Unit, Llandough Hospital, Penarth, South Glamorgan, Wales, United Kingdom Kenneth E. Warner, Ph.D., Professor, and Chairman, Department of Health Planning and Administration, School of Public Health, The University of Michigan, Ann Arbor, Michigan David H. Wegman, M.D., M.S., Professor, Environmental and Occupational Health Sciences, School of Public Health, University of California at Los Angeles, Los Angeles, California Hans Weill, M.D., Schlieder Foundation Professor of Pulmonary Medicine, Tulane University School of Medicine, New Orleans, Louisiana William Weiss, M.D., Professor Emeritus of Medicine, Hahnemann University, Philadelphia, Pennsylvania *R. Keith Wilson, M.D., Associate Professor of Medicine, Pulmonary Section, Baylor College of Medicine and The Methodist Hospital, Houston, Texas *Ronald W. Wilson, M.A., Director, Division of Epidemiology and Health Promotion, National Center for Health Statistics, Office of the Assistant Secretary for Health, Hyattsville, Maryland James B. Wyngaarden, M.D., Director, National Institutes of Health, Bethesda, Maryland Frank E. Young, M.D., Commissioner, Food and Drug Administra- tion, Rockville, Maryland The editors also acknowledge the contributions of the following staff members and others who assisted in the preparation of this Report. Erica W. Adams, Chief Copy Editor and Assistant Production Manager, Health and Natural Resources Department, Informatics General Corporation, Rockville, Maryland Richard H. Amacher, Director, Health and Natural Resources Department, Informatics General Corporation, Rockville, Mary- land John L. Bagrosky, Associate Director for Program Operations, Office on Smoking and Health, Rockville, Maryland Charles A. Brown, Programmer, Automation and Technical Services Department, Informatics General Corporation, Rockville, Mary- land Clarice D. Brown, Statistician, Office on Smoking and Health, Rockville, Maryland Richard C. Brubaker, Information Specialist, Health and Natural Resources Department, Informatics General Corporation, Rock- ville, Maryland Catherine E. Burckhardt, Secretary, Office on Smoking and Health, Rockville, Maryland xx Joanna B. Crichton, Copy Editor, Health and Natural Resources Department, Informatics General Corporation, Rockville, Mary- land Stephanie D. DeVoe, Programmer, Automation and Technical Services Department, Informatics General Corporation, Rockville, Maryland Terri L. Ecker, Clerk-Typist, Office on Smoking and Health, Rock- ville, Maryland Felisa F. Enriquez, Information Specialist, Health and Natural Resources Department, Informatics General Corporation, Rock- ville, Maryland James N. Ferguson, Reproduction Technician, Office Services De- partment, Informatics General Corporation, Rockville, Maryland Danny A. Goodman, Information Specialist, Health and Natural Resources Department, Informatics General Corporation, Rock- ville, Maryland Karen Harris, Clerk-Typist, Office on Smoking and Health, Rock- ville, Maryland Leslie J. Headlee, Information Specialist, Health and Natural Resources Department, Informatics General Corporation, Rock- ville, Maryland Patricia E. Healy, Technical Information Specialist, Office on Smoking and Health, Rockville, Maryland Timothy K. Hensley, Technical Publications Writer, Office on Smoking and Health, Rockville, Maryland Shirley K. Hickman, Data Entry Operator, Health and Natural Resources Department, Informatics General Corporation, Rock- ville, Maryland Ayse N. Hisim, Secretary, Health and Natural Resources Depart- ment, Informatics General Corporation, Rockville, Maryland Robert S. Hutchings, Associate Director for Information and Pro- gram Development, Office on Smoking and Health, Rockville, Maryland Leena Kang, Data Entry Operator, Health and Natural Resources Department, Informatics General Corporation, Rockville, Mary- land Carl M. Koch, Jr., Information Specialist, Health and Natural Resources Department, Informatics General Corporation, Rock- ville, Maryland Julie Kurz, Graphic Artist, Information Center Management De- partment, Informatics General Corporation, Rockville, Maryland Maureen Mann, Editorial Assistant, Office on Smoking and Health, Rockville, Maryland James G. Oakley, Library Acquisitions Clerk, Health and Natural Resources Department, Informatics General Corporation, Rock- ville, Maryland xxi Ruth C. Palmer, Secretary, Office on Smoking and Health, Rockville, Maryland Russell D. Peek, Library Acquisitions Specialist, Health and Natural Resources Department, Informatics General Corporation, Rock- ville, Maryland Roberta L. Phucas, Secretary, Office on Smoking and Health, Rockville, Maryland Margaret E. Pickerel, Public Information and Publications Special- ist, Office on Smoking and Health, Rockville, Maryland Raymond K. Poole, Production Coordinator, Health and Natural Resources Department, Informatics General Corporation, Rock- ville, Maryland Linda R. Sexton, Information Specialist, Health and Natural Re- sources Department, Informatics General Corporation, Rockville, Maryland Linda R. Spiegelman, Administrative Officer, Office on Smoking and Health, Rockville, Maryland Evelyn L. Swarr, Administrative Secretary, Automation and Techni- cal Services Department, Informatics General Corporation, Rock- ville, Maryland Debra C. Tate, Publications Systems Specialist, Publishing Systems Division, Informatics General Corporation, Riverdale, Maryland Jerry W. Vaughn, Development Technician, University of California at San Diego, San Diego, California Mary I. Walz, Computer Systems Analyst, Office on Smoking and Health, Rockville, Maryland Louise G. Wiseman, Technical Information Specialist, Office on Smoking and Health, Rockville, Maryland Pamela Zuniga, Secretary, University of California at San Diego, San Diego, California xxii TABLE OF CONTENTS Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Preface.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix Acknowledgments .................... ................................. x111 1. Introduction, Overview, and Summary and Conclusions ........................................................ 1 2. Occupation and Smoking Behavior in the United States: Current Estimates and Recent Trends . . . . . . . . 19 3. Evaluation of Smoking-Related Cancers in the Workplace.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 4. Evaluation of Chronic Lung Disease in the Workplace.. . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 5. Chronic Bronchitis: Interaction of Smoking and Occupation.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 6. Asbestos-Exposed Workers ................................. 195 7. Respiratory Disease in Coal Miners .................... 285 8. Silica-Exposed Workers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319 9. Occupational Exposures to Petrochemicals, Aromatic Amines, and Pesticides . . . . . , . . . . . . . . . . . . . . . . . . . . . . . 355 10. Cotton Dust Exposure and Cigarette Smoking ....... 399 11. Ionizing Radiation and Lung Cancer ................... 441 12. Smoking Intervention Programs in the Workplace.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 473 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 517 xx111 CHAPTER 1 INTRODUCTION, OVERVIEW, AND SUMMARY AND CONCLUSIONS CONTENTS Introduction Development and Organization of the 1985 Report Historical Perspective Overview Summary and Conclusions of the 1985 Report 3 Introduction Development and Organization of the 1985 Report The 1985 Report was prepared by the Office on Smoking and Health of the U.S. Department of Health and Human Services as part of the Department's responsibility, under Public Law 91-222, to report new and current information on smoking and health to the United States Congress. The scientific content of this Report is the collective work of 100 scientists in the fields of both smoking and occupational health. Individual manuscripts were written by experts who are recognized for their understanding of specific content areas. Each chapter was subjected to an intensive peer review, whereby comments were solicited from four to six individuals knowledgeable in that particular area. After these comments were incorporated, the entire Report was submitted to distinguished experts representing a balance of opinion in occupational disease and smoking and health. Concurrent with this latter review, the manuscript was also submit- ted to various U.S. Public Health Service agencies for review. Throughout the entire report compilation process the Office on Smoking and Health had the advice and consultation of four internationally known scientists. These individuals represent exper- tise in the fields of both smoking and occupation. They are Dr. Lester Breslow, University of California at Los Angeles, Dr. Marcus Key, University of Texas Health Science Center, Dr. Irving Selikoff, the Mount Sinai Medical Center, and Dr. Jesse Steinfeld, Medical College of Georgia. From the outset, this panel of experts was instrumental in recommending the Report content and outline, suggesting individual authors and reviewers, and providing overall guidance during each stage of the compilation process. Each also served as an overall reviewer of the completed manuscript. The 1985 Report contains a Foreword by the Acting Assistant Secretary for Health, a Preface by the Surgeon General of the U.S. Public Health Service, and the following chapters: o Chapter 1. Introduction, Overview, and Summary and Con- clusions o Chapter 2. Occupation and Smoking Behavior in the United States o Chapter 3. Evaluation of Smoking-Related Cancers in the Workplace o Chapter 4. Evaluation of Chronic Lung Disease in the Workplace o Chapter 5. Chronic Bronchitis: Interaction of Smoking and Occupation o Chapter 6. Asbestos-Exposed Workers o Chapter 7. Respiratory Disease in Coal Miners o Chapter 8. Silica-Exposed Workers 5 a Chapter 9. Occupational Exposures to Petrochemicals, Aromatic Amines, and Pesticides o Chapter 10. Cotton Dust Exposure and Cigarette Smoking o Chapter 11. Ionizing Radiation and Lung Cancer o Chapter 12. Smoking Intervention Programs in the Work- place Historical Perspective More than two centuries ago, the relationship between occupation- al exposure and health outcome was presented by a noted English practitioner of surgery. Dr. Percival1 Pott (1733-1788), in his Chirugical Observation-s (17751, described this first scientific observa- tion as a "superficial, painful ragged, ill-looking sore with hard and rising edges" that appeared in chimney sweeps, who almost always began working when they were very young and small enough to fit down a chimney. This malady was appropriately tagged "chimney sweep's cancer." Soon after the turn of the 19th century, additional reports confirmed Dr. Pott's observations. Only shortly before Dr. Pott's description was published, Dr. John Hill (1716?-17751, in his Cautions Against the Immoderate Use of Snuff; described an association between tobacco use and cancer. Hill reported on two case histories and observed that "snuff is able to produce . . . swellings and excrescences" in the nose, and he believed them to be cancerous. Although Dr. Pott's startling report and description of the deplorable use of children as chimney sweeps was published in 1775, it was not until nearly a century and a half later, in 1914, that Yamagawa and Ichikawa were able to demonstrate the carcinogenic nature of the hydrocarbons in soot and tar. Almost 20 years later, in 1933, the proximate carcinogen 3,4-benzypyrene was isolated from coal tar by Cook, Hewett, and Hieger. Also in the 1920s and 1930s scientists began investigating the possible association between cigarette smoking and cancer, and near the end of World War II, several scientists had noted the higher percentages of cigarette smokers among cancer patients, particular- ly those with lung cancer. In 1962, when the Surgeon General's Advisory Committee on Smoking and Health began weighing the scientific evidence for its 1964 Report, the causal significance of the association of cigarette smoking and disease was evaluated by strict criteria, none of which taken alone was sufficient for a causal judgment. These criteria today form the basis for the continued judgment that cigarette smoking is causally related to a number of disease processes. Overview Cigarette smoking is clearly the major cause of lung cancer and chronic lung disease identified for the U.S. population. The role that cigarette smoking plays in the development of cancer was extensive- ly reviewed in 1982 Report of the Surgeon General and chronic obstructive lung disease was reviewed in 1984. However, cigarette smoking is not the only cause of lung cancer or chronic lung disease in the U.S. population. A number of occupational exposures are well established as causes of cancer and chronic lung disease, and it is reasonable to expect that ongoing investigation of workplace expo- sures will continue to expand our understanding of the hazards of specific exposures and increase our ability to protect U.S. workers. This Report examines the contributions of cigarette smoking and a number of workplace exposures to lung cancer and chronic lung disease among occupations in which specific hazardous exposures are known to occur. It is possible from the data presented to identify a causal role for both smoking and certain workplace exposures in lung cancer and disability from chronic lung disease. It is also known that the occupational hazards reviewed in this Report frequently occur on a substrate of risk and injury produced by cigarette smoking. The combination of exposures may influence the nature or extent of the disease produced by the isolated exposures (interact); both may act to produce the same disease, or may produce separate injuries to the lung that in combination result in more severe disability than would be expected from the isolated injuries. In addition, the worksite may represent a setting in which a substantial number of workers begin to smoke, and may provide an environment that either supports or discourages the efforts of individual workers to stop smoking. The ability to alter the adverse health outcomes of workers exposed to occupational hazards requires both an under- standing of the disease risks that result from individual and combined exposure and a knowledge of how changes in the worksite can alter the pattern of disease occurrence. Many of the major improvements in public health during the last century and the first part of this century were produced through the control of infectious diseases. The key to this success frequently was the identification of the causal agent, with the subsequent elimina- tion of exposure to the agent or immunization against the agent. The criteria for establishing the causality of an infectious agent were expressed by Robert Koch in 1877 and are commonly referred to as Koch's postulates. They are the following: 1. The agent must be shown to be present in every case of the disease by isolation in pure culture. 2. The agent must not be found in cases of other disease. 7 3. Once isolated, the agent must be capable of reproducing the disease in animal experiments. 4. The agent must be recovered from the experimental disease produced. These postulates served well in identifying the causal agents in acute infectious processes; frequently their identification was a critical part of their successful control. The major diseases responsible for death and disability in the latter half of the 20th century are chronic heart and lung disease and cancer. These diseases, which now account for over half of all deaths in the United States annually, are commonly the result of chronic exposures to noninfectious occupational and lifestyle influ- ences, may be caused by a number of agents acting independently, and may also result from more than one agent contributing to the disease process in any given individual. For these reasons, Koch's postulates have little relevance for establishing causality in lifestyle and occupational exposures, and new criteria for causality have been developed. These criteria rely heavily on epidemiologic data and include an examination of the consistency, strength, specificity, coherence, and temporal relationship of the association between the agent and the disease as well as the evidence of the biologic mechanisms by which the agent produced the disease. The multifactorial etiology and chronic exposures that character- ize cancer and chronic lung disease also have implications for control of these diseases in the worksite. One of the important public health achievements of this century has been the identification of hazard- ous agents in the workplace, with subsequent reductions in these exposures through changes in environmental levels of the agent, modification of work practices, and alteration of manufacturing practices. These changes were the result of regulation and voluntary agreement, and they reflect the action and concern of labor, management, Government, and the insurance industry. The result, in some industries, has been a dramatic reduction in the exposure to hazardous agents in the worksite and in the disease that would have been produced by these exposures. As this Report clearly documents, however, cigarette smoking may alter the amount of disease or level of disability produced by hazardous occupational exposures. For cancer, this alteration may come in the form of adding an additional number of cancer cases, or of the combined exposure synergistically increasing the number of cancers. On an individual level, our understanding of the process of carcinogenesis suggests that both agents may contribute to individu- al cancer rather than some cases being caused exclusively by an occupation exposure and other cases being caused exclusively by cigarette smoking. For lung disease, the combination of cigarette smoking and exposure to a hazardous workplace agent may combine to produce similar injuries or may produce independent disease processes in the same lung that result in greater disability than with either exposure separately. The public health importance of interaction between smoking and an occupational exposure is typified by the relationship between cigarette smoking and asbestos exposure among asbestos workers. A number of studies published in this country and abroad have demonstrated an approximately fivefold excess risk for lung cancer among nonsmoking asbestos insulation workers. Smoking in non- asbestos-exposed populations increases the lung cancer risk by approximately tenfold. However, the risk is more than fiftyfold greater if the asbestos worker also smokes. The risk in cigarette- smoking asbestos workers is greater than the sum of the risk of the independent exposures, and is approximated by multiplying the risks of the two separate exposures. Thus, the interaction of cigarette smoking and asbestos exposure is multiplicative in nature. To state this in another way, for those workers who both smoke and are exposed to asbestos, the risk of developing and dying from lung cancer is 5,000 percent greater than the risk for individuals who neither smoke nor are exposed. Among these asbestos workers, the extent of disease produced by asbestos is conditioned by the smoking habits of the asbestos-exposed population. As is also evident, attempts to control asbestos-related lung cancer can have a maximal impact only if they include successful programs to change smoking behavior as well as efforts aimed at reducing levels of asbestos dust exposure. Elimination of the contribution made by smoking to disease and disability in the worksite is beneficial, even in the absence of synergistic interaction between smoking and workplace exposures. Even with an additive risk for an exposed population, both agents probably contribute to the cancer that develops in an individual, and removing that contribution is an important benefit to that individu- al. In addition, a given degree of impairment produced by an occupational agent will result in less disability in an individual without concomitant lung injury due to smoking than in a worker who has chronic obstructive lung disease due to smoking. The focus on individuals rather than on populations when considering strategies to control occupationally related diseases also helps clarify the concept of a "safe" worksite. The same number of lung cancers may occur in a population with a high smoking prevalence and a low asbestos exposure and ;i population with a low smoking prevalence and a high asbestos exposure. This similarity of population risks does not suggest that the level of acceptable or "safe" dust exposure l:an be adjusted on the basis of the smoking 9 prevalence in the population. It may be reasonable to select nonsmokers for jobs in which smokers would be at much greater risk, but this approach should never be used as a justification for accepting occupational exposure levels that result in risk for those exposed. The goal should always be the elimination of as much of the disease as possible in the working population rather than the lowering of the disease rate to the population norm. Factors in the worksite may also influence smoking initiation and smoking cessation. Chapter 2 of this Report updates the previously reported increased smoking prevalence among blue-collar workers compared with white-collar workers. It also reports two analyses that suggest the workplace may play an important role in smoking behavior. The mean age of initiation reported confirms that the majority of smokers begin smoking prior to or during high school. However, a substantial fraction also begin to smoke after high school. Little is known about the influences that may predispose individuals to become smokers at this age. One of the major life experiences occurring at the same time is entry into the workforce, particularly for blue-collar and clerical workers, and the work environment may be a major factor capable of predisposing an individual toward or away from becoming a smoker. A second important consideration that emerges from chapter 2 is the markedly lower prevalence of successful smoking cessation among blue-collar workers compared with white-collar workers. This difference in cessation is not explained by differences in rates of initiation, and almost equal percentages of current smokers have made a serious attempt to quit and failed. This suggests that the majority of both groups of workers have attempted to become nonsmokers, but blue-collar workers have been less successful. Once again, a potential role for the workplace environment in reinforcing or inhibiting successful cessation may help to explain these differ- ences in the prevalence of former smokers. If a workplace is to be considered "safe," one very important criterion is the absence of exposures to agents that can cause disease. Equally important, however, is that safety should include a work- place that neither encourages initiation nor discourages cessation of cigarette smoking. As demonstrated in the final chapter of this Report, the worksite may provide a focus for the promotion of healthy behavioral change in the workforce, but at a minimum, should not be a focus that encourages behaviors that compromise a worker's health. Summary and Conclusions of the 1985 Report The major conclusions of this Report are clear. They are the following: 10 For the majority of American workers who smoke, cigarette smoking represents a greater cause of death and disability than their workplace environment. In those worksites where well-established disease outcomes occur, smoking control and reduction in exposure to hazardous agents are effective, compatible, and occasionally synergistic approaches to the reduction of disease risk for the individual worker. Individual chapter summaries and conclusions follow. Occupation and Smoking Behavior in the United States: Current Estimates and Recent Trends 1. Among men, a substantially higher percentage of blue-collar workers than white-collar workers currently smoke cigarettes. Operatives and kindred workers have the highest rate of current smoking (approaching 50 percent), with professional, technical, and kindred workers having the lowest rates of current smoking (approximately 26 percent). 2. Among women, blue-collar versus white-collar differences are less pronounced, but still show a higher percentage of current smokers among blue-collar workers. Occupational categories with the highest rates of current smoking include craftsmen and kindred workers (approximately 45 percent current smok- ers) and managers and administrators (38 percent), with the lowest rate of current smoking occurring among women employed in professional, technical, and kindred occupations (26 percent). 3. Occupational differences in daily cigarette consumption are generally modest. For both men and women, the highest daily consumption of cigarettes occurs among managers and admin- istrators and craftsmen and kindred workers. 4. Blue-collar workers (both men and women) report an earlier onset of smoking than white-collar workers. A substantial fraction of smokers report initiation of smoking at ages coincident with their entry into the workforce. 5. Blue-collar occupations have a lower percentage of former smokers than white-collar occupations; this difference is most pronounced among men. Among women, the pattern for homemakers closely parallels that of white-collar women. 6. Black workers have higher smoking rates than white workers, with black male blue-collar workers exhibiting the highest smoking rate. Black workers also have lower quit rates than white workers. In contrast, white workers of both sexes are more likely to be heavy smokers regardless of occupational category. 11 Evaluation of Smoking-Related Cancers in the Workplace 1. Cigarette smoking and occupational exposures may interact biologically, within a given statistical model and in their public health consequences. The demonstration of an interaction at one of these levels does not always characterize the nature of the interaction at the other levels. 2. Information on smoking behaviors should be collected as part of the health screening of all workers and made a part of their permanent exposure record. 3. Examination of the smoking behavior of an exposed population should include measures of smoking prevalence, smoking dose, and duration of smoking. 4. Differences in age of onset of exposure to cigarette smoke and occupational exposures should be considered when evaluating studies of occupational exposure, particularly when the ex- posed population is relatively young or the exposure is of relatively recent onset. Evaluation of Chronic Lung Disease in the Workplace 1. Existing resources for monitoring the occurrence of occupation- al lung diseases are not comprehensive and do not include information on cigarette smoking. Other approaches, such as registries, might offer more accurate data and facilitate research related to occupational lung diseases. Because of the variability in diagnostic criteria for chronic lung disease, in I studies on occupational lung diseases emphasis should be placed on measures of physiological change, roentgenographic abnormality, and other objective measures. 2. Further studies that correlate lung function with histopatholo- gy should be carried out in occupationally exposed smokers and nonsmokers. 3. The effects of cigarette smoking on the chest x ray should be clarified. In particular, the sensitivity of the IL0 classification to smoking-related changes should be further evaluated in healthy populations. 4. To determine if smoking is reported with bias by occupational- ly exposed workers, self-reported histories should be compared with biological markers of smoking in appropriate populations. 5. Mechanisms through which specific occupational agents and cigarette smoking might interact should be systematically considered. Both laboratory and epidemiological approaches should be used to evaluate such interactions. 6. Statistical methods for evaluating interaction require further development. In particular, the biological implications of conventional modeling approaches should be explored. Fur- ther, the limitations posed by sample size for examining 12 independent and interactive effects should be evaluated. The consequences of misclassification by exposure estimates and of the colinearity of exposure variables should also be addressed. 7. The role of cigarette smoking in the "healthy worker effect" requires further evaluation. 8. Approaches for apportioning the impairment in a specific individual between occupational causes and cigarette smoking should be developed and validated. Chronic Bronchitis: Interaction of Smoking and Occupation 1. Chronic simple bronchitis has been associated with occupation- al exposures in both nonsmoking exposed workers and popula- tions of exposed smokers in excess of rates predicted from the smoking habit alone. Among these exposures are coal, grain, silica, the welding environment, and to a lesser extent, sulfur dioxide and cement. 2. The evidence indicates that the effects of smoking and those occupational agents that cause bronchitis are frequently addi- tive in producing symptoms of chronic cough and expectora- tion. Smoking has commonly been demonstrated to be the more important factor in producing these symptoms. Asbestos-Exposed Workers 1. Asbestos exposure can increase the risk of developing lung cancer in both cigarette smokers and nonsmokers. The risk in cigarette-smoking asbestos workers is greater than the sum of the risks of the independent exposures, and is approximated by multiplying the risks of the separate exposures. 2. The risk of developing lung cancer in asbestos workers increases with increasing number of cigarettes smoked per day and increasing cumulative asbestos exposure. 3. The risk of developing lung cancer declines in asbestos workers who stop smoking when compared with asbestos workers who continue to smoke. Cessation of asbestos exposure may result in a lower risk of developing lung cancer than continued exposure, but the risk of developing lung cancer appears to remain significantly elevated even 25 years after cessation of exposure. 4. Cigarette smoking and asbestos exposure appear to have an independent and additive effect on lung function decline. Nonsmoking asbestos workers have decreased total lung capac- ities (restrictive disease). Cigarette-smoking asbestos workers develop both restrictive lung disease and chronic obstructive lung disease (as defined by an abnormal FEV,/FVC), but the evidence does not suggest that cigarette-smoking asbestos 13 workers have a lower FEV,/FVC than would be expected from their smoking habits alone. 5. Both cigarette smoking and asbestos exposure result in an increased resistance to airflow in the small airways. In the absence of cigarette smoking, this increased resistance in the small airways does not appear to result in obstruction on standard spirometry as measured by FEV,/FVC. 6. Asbestos exposure is the predominant cause of interstitial fibrosis in populations with substantial asbestos exposure. Cigarette smokers do have a slightly higher prevalence of chest radiographs interpreted as interstitial fibrosis than nonsmok- ers, but neither the frequency of these changes nor the severity of the changes approach levels found in populations with substantial asbestos exposure. 7. The promotion of smoking cessation should be an intrinsic part of efforts to control asbestos-related death and disability. Respiratory Disease in Coal Miners 1. Coal dust exposure is clearly the major etiologic factor in the production of the radiologic changes of coal workers' pneumo- coniosis (CWP). Cigarette smoking probably increases the prevalence of irregular opacities on the chest roentgenograms of smoking coal miners, but appears to have little effect on the prevalence of small rounded opacities or complicated CWP. 2. Increasing category of simple radiologic CWP is not associated with increasing airflow obstruction, but increasing coal dust exposure is associated with increasing airflow obstruction in both smokers and nonsmokers. 3. Since the introduction of more effective controls to reduce the level of coal dust exposure at the worksite, cigarette smoking has become the more significant contributor to reported cases of disabling airflow obstruction among coal miners. 4. Cigarette smoking and coal dust exposure appear to have an independent and additive effect on the prevalence of chronic cough and phlegm. 5. Increasing coal dust exposure is associated with a form of emphysema known as focal dust emphysema, but there is no definite evidence that extensive centrilobular emphysema occurs in the absence of cigarette smoking. 6. The majority of studies have shown that coal dust exposure is not associated with an increased risk for lung cancer. 7. Reduction in the levels of coal dust exposure is the only method available to reduce the prevalence of simple or complicated CWP. However, the prevalence of ventilatory disabilities in coal miners could be substantially reduced by reducing the prevalence of cigarette smoking, and efforts aimed at reducing 14 ventilatory disability should include efforts to enhance success- ful smoking cessation. Silica-Exposed Workers 1. Silicosis, acute silicosis, mixed-dust silicosis, silicotuberculosis, and diatomaceous earth pneumoconiosis are causally related to silica exposure as a sole or principal etiological agent. 2. Epidemiological evidence, based on both cross-sectional and prospective studies, demonstrates that silica dust is associated with chronic bronchitis and chronic airways obstruction. Silica dust and smoking are major risk factors and appear to be additive in producing chronic bronchitis and chronic airways obstruction. Most studies indicate that the smoking effect is stronger than the silica dust effect. 3. Pathological studies describe mineral dust airways disease, which is morphologically similar to the small airways lesions caused by cigarette smoking. 4. A number of studies have demonstrated an increased risk of lung cancer in workers exposed to silica, but few of these studies have adequately controlled for smoking. Therefore, while the increased standardized mortality ratios for lung cancer in these populations suggest the need for further investigation of a potential carcinogenic effect of silica expo- sure (particularly in a combined exposure with other possible carcinogens), the evidence does not currently establish whether silica exposure increases the risk of developing lung cancer in man. 5. Smoking control efforts should be an important concomitant of efforts to reduce the burden of silica-related illness in working populations. Occupational Exposures to Petrochemicals, Aromatic Amines, and Pesticides 1. The biotransformation of industrial toxicants can be modified at least to some extent by the constituents of tobacco smoke through enzyme induction or possibly inhibition. Both tobacco smoke and some industrial pollutants contain substances capable of initiating and promoting cancer and damaging the airways and lung parenchyma. There is, therefore, an ample biologic basis for suspecting that important interactive effects between some workplace pollutants and tobacco smoke exist. 2. In mortality studies of coke oven workers and gas workers, convincing evidence has indicated that work exposures to oven effluents are causing an excess risk of lung cancer in spite of the lack of adequate information on smoking. Other mortality studies that suggest small increases in smoking-related dis- 15 eases, such as pancreatic cancer in refinery workers, cannot be interpreted without more information on smoking. 3. For bladder cancer, the interactions between smoking and occupational exposure are unclear, with both additive and antagonistic interactions having been demonstrated. 4. The risk of pulmonary disability in rubber workers was increased when smoking and occupational exposure to particu- lates were combined. There are few empirical animal experi- ments that demonstrate interactive effects between cigarette smoking and various industrial chemicals for lung disease. Cotton Dust Exposure and Cigarette Smoking 1. Byssinosis prevalence and severity is increased in cotton textile workers who smoke in comparison with workers who do not smoke. 2. Cigarette smoking seems to facilitate the development of byssinosis in smokers exposed to cotton dust, perhaps by the prior induction of bronchitis. Cotton mill workers of both sexes who smoke have a consistently greater prevalence of bronchitis than nonsmokers. 3. The importance of cigarette smoking to byssinosis prevalence seems to grow with rising dust levels (a smoking-cotton dust interaction). At the highest dust levels, cigarette smoke was found to interact with cotton dust exposure to substantially increase the acute symptom prevalence. 4. Nonsmokers with byssinosis have lower preshift lung function and a greater cross-shift decline in lung function than asymp- tomatic workers, and those workers with bronchitis generally have lower preshift lung function than those without bronchi- tis. In general, smokers have lower lung function than non- smokers among cotton workers, both in those with bronchitis and in those with byssinosis. 5. Although the average forced expiration values measured at the start of a shift are reduced among smokers, the cross-shift decline in function does not seem to be affected by smoking status. 6. The contribution of the acute byssinotic symptoms (grades l/2 and 1) to the subsequent development of what have been termed the chronic forms (grade 3) of byssinosis (which include airways obstruction) is not well documented; however, chronic airflow obstruction has been found more frequently in cotton textile workers than in control populations, and this lung function loss appears to be additive to that caused by cigarette smoking. 7. Cotton dust exposure is significantly associated with mucous gland volume and peripheral goblet cell metaplasia in non- 16 smokers, a pathology consistent with bronchitis. Among ciga- rette smokers, the interaction of cotton textile exposure and smoking is demonstrable for goblet cell hyperplasia. Centrilo- bular emphysema is found only in association with cigarette smoking and pipe smoking. There is no emphysema association found with cotton dust exposure. 8. The evidence does not currently suggest an excess risk of lung cancer among cotton textile workers. Ionizing Radiation and Lung Cancer 1. There is an interaction between radon daughters and cigarette smoke exposures in the production of lung cancer in both man and animals. The nature of this interaction is not entirely clear because of the conflicting results in both epidemiological and animal studies. 2. The interaction between radon daughters and cigarette smoke exposures may consist of two parts. The first is an additive effect on the number of cancers induced by the two agents. The second is the hastening effect of the tumor promoters in cigarette smoke on the appearance of cancers induced by radiation, so that the induction-latent period is shorter among smokers than nonsmokers and the resultant cancers are distributed in time differently between smokers and nonsmok- ers, appearing earlier in smokers. Smoking Intervention Programs in the Workplace 1. Smoking modification and maintenance of nonsmoking status among initial quitters has the promise of being more successful in worksite programs than in clinic-based programs. Higher cessation rates in worksite programs are achieved with more intensive programs. 2. Incentives for nonsmoking appear to be associated with higher participation and better success rates. Further research is needed to specify the optimal types of incentive procedures. 3. Success of a worksite smoking program depends upon three primary factors: the characteristics of the intervention pro- gram, the characteristics of the organization in which the program is offered, and the interaction between these factors. 4. Research is needed on recruitment strategies and participation rates in worksite smoking programs and on Ihe impact of interventions on the entire workforce of a compa :y. 5. More investigations are needed on worksite c:-~arr~~!eristics associated with the success of occupational programs and on comprehensive programs including components such as quit- smoking contests, no-smoking policies, physician messages. and self-help materials in addition to smoking cessation clinics. 6. The implementation of broadly based health promotion efforts in the workplace should be encouraged, with smoking interven- tions representing a major component of the larger effort to improve health through a worksite focus. 18 CHAPTER 2 OCCUPATION AND SMOKING BEHAVIOR IN THE UNITED STATES: CURRENT ESTIMATES AND RECENT TRENDS CONTENTS Introduction Patterns of Employment Smoking Prevalence Daily Cigarette Consumption Age of Initiation Quitting Behavior Recent Changes in Smoking Behavior Birth Cohorts Race Summary and Conclusions Technical Addendum: National Health Interview Survey Estimates References Appendices 21 Introduction Estimates of current smoking behavior reported in this section of the Surgeon General's Report were obtained from the 1978, 1979, and 1980 National Health Interview Surveys (NHIS). A data tape was prepared by the National Center for Health Statistics to allow linkages across surveys, thereby permitting analyses of the com- bined 1978-1980 NHIS (n=49,715). The majority of the analysis presented in this chapter were conducted on the population aged 20 to 64 (n =38,527). Given the large samples and exceptionally high response rates of NHIS, these estimates are generally regarded as the best available estimates of national smoking patterns. To examine recent lo-year changes in smoking behavior by occupation- al category, the 1978-1980 NHIS estimates have also been compared with the 1970 NHIS estimates for selected smoking variables. A more detailed description of the NHIS data base is provided in the Technical Addendum to this section. Patterns of Employment Before characterizing the smoking behavior of the U.S. adult workforce, it will be useful to describe the patterns of employment for men and women. As is shown in Table 1, men are more likely to be employed in professional and technical, management, and blue- collar occupations. Women are more likely to be employed in professional and technical and clerical and service occupations or to be homemakers. Although there was an increase in participation by women in white-collar occupations between 1970 and 1980, the ranking of occupational categories by their relative frequency for both sexes remained about the same in 1980 as it did in 1970. Because of their low relative frequency, farm, sales, and clerical workers, laborers, and service workers have less impact on the smoking behavior of the total male workforce, and female farm workers, laborers, craftsmen and kindred workers, sales workers, and managers and administrators have a modest impact on the smoking behavior of the total female workforce. Smoking Prevalence Surveys have repeatedly shown that blue-collar workers are more likely than white-collar workers to smoke cigarettes (US DHEW 1979). Recent estimates from NHIS continue to substantiate this fimding (Table 2). Overall, smoking rates for blue-collar men (47.1 percent) exceed that of white-collar men (33.0 percent). The same pattern holds for women, but is less pronounced, with smoking rates among blue-collar women (38.1 percent) exceeding that of white- collar women (31.9 percent). Among women, this white-collar-blue- 23 TABLE I.-Estimates of the occupational distribution of men and women, aged 20 to 64 years, United States, 1970-1980 0ccupat10n Men Women 1970 1978-80 1970 197-o Currently employed 87.8 85.1 47 9 57.3 Whitecollar total 39.2 39.2 31.1 40.5 Professional. technical. and kmdred workers Managers and admmistrators. except farm Sales workers Clerical and kmdred workers 14.2 14.9 7.9 11.4 13.3 13 5 2.6 4.9 50 5.3 3.4 3.6 6.8 5.5 17.1 20.6 Blue-collar total Craftsmen and kindred workers Operatives and kindred workers Laborers. except farm Serwce 43.1 40.8 9.0 93 19.9 20 7 0.8 1.5 18.1 14.6 8.0 7.2 5.1 5.5 0.2 0.6 5.4 6.1 10.3 IO.8 Farm 37 2.9 0.5 0.6 Unemployed Usual actwty. homemaking 36 4.1 3.2 4.3 - 52.5 41.7 SOTE The whitecollar. bluecollar. Service. and farm occupational categorres are mutually exclusive. however. those class,fied as "Howmak:ng" or "Unrmployed" may also be classified ,n an occupat,onal group on the baxs of a rrcent or part-tune Job. resulting in a small degree ofoveriap between cate~urles SOURCE Nar~onal Center fur Health Srat~stics. Nat~anal Health Inrenww Surveys. 1970 and 197G1980 `combInedI ,See TechnIcal .4ddendum ) collar difference exists only for the younger age group (aged 20 to 441; for older women (aged 45 to 64) there is virtually no difference in smoking prevalence between these two categories of workers. For men, the highest rates of current smoking occur among craftsmen and kindred workers, operatives and kindred workers, laborers, service workers, and the unemployed. The lowest smoking rates for men occur among professional, technical, and kindred workers, managers and administrators, clerical and kindred work- ers, and farm workers. 24 TABLE 2.-Estimates of the percentage of current smokers by sex, age, and occupation, aged 20 to 64 years, United States, 1978-1980 Occupation Women Men ; otal 20-44 4wz4 Total z&44 45-64 Total 332 34.2 314 409 414 39.8 Currently employed 33.3 34.0 31 a 39 9 409 37 7 Whmz-collar total 319 31.9 319 33 0 33 5 32.2 Professmnal, technical, and kindred workers Managers and administrators, except farm Sales workers Clerical and kmdred workers 26.5 26.1 27 9 257 253 26.6 38.3 37.8 39.2 36 3 38.9 32.2 33.3 33.2 33.5 40.6 42.0 38.0 33.2 33.9 31.4 37.7 36.4 40.4 Blue-collar total 38.1 41.3 31.9 47 1 48.7 43.6 Craftsmen and kmdred workers Operatwes and kindred workers Laborers, except farm 44.6 45.4 43.0' 46.1 47.8 42.6 37.0 40.2 30.8 48.6 50.4 44.5 36.2 43.0' 14.1 o 46.8 47.3 45.1 Service 37.4 39.8 32.7 48.3 46.0 Farm 22.6 28.9 34.5 Unemployed 39.6 33.0 31.3 ' 41.7 351 7.1' 30.4 30.4 47.5 31.5 53.1 Usual actwity. homemakmg 53.9 - 50.8 ' -- 1W cases m the denominator ~unweighted sample8 SOURCE: National Center for Health Statistics. National Health Intenxw Surveys, 1978-1980 icombine& ~See Technical Addendum.1 For women 20 to 64 years of age, the highest smoking rates are found among craftsmen and kindred workers and managers and administrators. Among women 20 to 44 years of age, there are also relatively high smoking rates among operatives and kindred work- ers, service workers, and the unemployed. The lowest rates of current smoking occur among professional, technical, and kindred workers, regardless of age. For homemakers, the category represent- ing nearly 42 percent of all women aged 20 to 64, the prevalence of smoking among those aged 20 to 44 is midway between the 25 prevalence rates for white-collar and blue-collar occupations. How- ever, among women 45 to 64 years of age, smoking rates vary little by occupational group (with the single exception of managers and administrators), with white collar-workers, blue-collar workers, and homemakers all having approximately the same smoking preva- lence. Among men, a more detailed breakdown of smoking by occupation (Table 3) shows that painters, truck drivers, construction workers, carpenters, auto mechanics, and guards and watchmen have the highest rates of current smoking (among occupations having 100 or more cases in the 1978-1980 NHIS), each exceeding 50 percent. In contrast, electrical and electronic engineers, lawyers, and secondary school teachers have the lowest rates of current smoking, all under 25 percent. Among women, waitresses have a noticeably higher rate of current smoking than other groups (Table 4), followed by cashiers, assem- blers, nurses aides, machine operators, practical nurses, and packers and wrappers-all of whom have rates of current smoking that equal or surpass 40 percent. The lowest rates of smoking occur among women employed as elementary school teachers, food service work- ers, bank tellers, and sewers and stitchers. Because of the exemplar role of physicians and nurses in regard to health, their smoking rates are of special interest. Although the sample is relatively small, physicians have among the lowest rates of current smoking (18.1 percent). Among nurses, the pattern of smoking reflects the white-collar-service worker distinction; regis- tered nurses have among the lowest rates of current smoking, but practical nurses have among the highest rates (Table 4). Daily Cigarette Consumption For men, occupational differences in cigarette consumption do not follow the same patterns observed for prevalence. On the average, adult male white-collar smokers consume 24 cigarettes per day, essentially the same as the number of cigarettes consumed by blue- collar smokers (23.3) (Table 5). In virtually all occupational sub- groups, adult men report an average daily consumption exceeding 20 cigarettes. Consumption levels are highest among managers and administrators and sales workers. These numbers represent daily cigarette consumption and need to be interpreted with some caution, as there may be a substantial underreporting of cigarette consump- tion, and the tendency to underreport may not be constant across occupational categories. For women, no difference in consumption is found between white- collar and blue-collar smokers. On the average, white-collar female smokers consume 19.5 cigarettes per day, compared with 19.8 26 `FABLE 3.-Specific occupations with highest and lowest estimates of current smoking, men, aged 20 to 64 years, United States, 1978-1980 Occupatio" Highest rates 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Painters. construction and maintenance (5101 Truck drivers (715) Construction laborers. except carpenters' helpers (7511 Carpenters (4151 Auto mechamcs 14731 Guards and watchmen (9621 Janitors and sextons (903) Assemblers WIZI Electricians 14301 Sales representatives. wholesale trade (282) Lowest rates 1. Electrical and electronic engineers 10121 16.2 2. Lawyers (031) 21.9 3. Secondary school teachers (144) 24.9 4. Accountants (001) 26.8 5. Real estate agents and brokers (270) 27.8 6 Farmers N301) 28.1 55.1 53.6 53.0 50.8 50.5 505 49.8 48.7 48.3 48.1 NOTE: Adapted from Table 22 in Technical Addendum Only thme occupatmns with at least 100 men (aged 20 to 641 in the 197%1980 NHIS are Included Numbers in parentheses denote code values from the U.S. Bureau of the Census 1970 classlticatmn of occupations. SOURCE: National Center for Health Statistics, Natmnal Health Interview Surveys. 197t%1980 (combmed). (See Technical Addendum.) cigarettes for blue-collar smokers, 19.4 cigarettes for homemakers, and 19.0 cigarettes for service workers. Female smokers employed as managers or administrators or as craftsmen or kindred workers report the highest consumption levels, averaging more than 20 cigarettes per day; women employed in professional, technical, or kindred occupations report lower average daily consumption. How- ever, like the men, these differences are not large, averaging fewer than two to four cigarettes per day. The higher the average daily consumption of cigarettes within an occupational group, the more likely it is that this group will also contain a higher percentage of heavy smokers (more than 20 or more than 40 cigarettes a day). Overall, 72 percent of the male smokers employed in white-collar occupations reported smoking more than 20 27 TABLE 4.-Specific occupations with highest and lowest estimates of current smoking, women, aged 20 to 64 years, United States, 1978-1980 OccupatKm Current smokers IpercentageJ Highest rates 1 Wamesses 19151 2 Cashiers 13101 3 Assemblers 1602 4 Nurses aides. orderhes. and attendants ,925) 5 .Machine operatives 16901 6 Practxal nurses 19261 i Packers and wrappers, excluding meat:produce 16431 8 Checkers, exammers. and inspectors; manufacturmg (6101 9 Managers and administrators n e.c. ' 12451 10 Hairdressers and cosmetologtsts 49441 Lowest rates 51.1 44.2 42.9 41.0 41.0 40.3 40.0 39.3 38.0 37.5 I Elementary school teachers (1421 19.8 2. Food service workers 89161 24.6 3 Secondary school teachers 11441 24.8 4 Bank tellers 13011 25.7 5 Sewers and stlrchers 1663: 25.8 6 Regtstered nurses 0751 27.2 7 Child care workers, excludmg prwate households (9421 28.9 SOTE Adapted from Table Z m Technical Addendum Only those occupatmns with at least 1W women (aged 20 to 64 m the lY7&1YR(l SHIS are mciuded Numb+vs m parentheses denote code values from the U S. Bureau of the (`ensus 1970 ciass,ficat~un 01 occupations Sot elsewhere ciawfied SOURCE Satmnal Center for Health Srat,st,cs. National Health Inrerwew Surveys. 1978-1880 ~combmedl See Technical Addendum cigarettes a day, and over 21 percent reported smoking 40 or more cigarettes a day (Table 6). Comparable figures for blue-collar smokers are 72 percent and 18 percent, respectively. Among adult women (Table 71, the percentage of heavy smokers is generally lower than for men, with women employed as craftsmen or kindred workers reporting higher percentages of heavy smoking than other female occupational groups. The pattern for homemakers closely parallels that of white-collar workers, but service workers have slightly lower rates of heavy smoking than white-collar workers. For both men and women, and across virtually all occupational groups, smokers 45 years of age or older are more likely 28 TABLE B.-Estimates of average daily cigarette consumption among current smokers by sex, age, and occupation, aged 20 to 64 years, United States, 1978-1980 Occupatuxl women .Men TOtal 2&44 4%64 Total 2M4 45-a Total 19.3 19.1 19.6 23.2 22.2 25 1 Currently employed 19 2 19 0 19 a 23 4 22 4 25.6 White-collar total 19 5 19 1 20 4 24 0 "2 6 26.9 Professional. technical, and kindred workers Managers and administrators. except farm Sales workers Clerical and kindred workers 18 3 17 9 19 3 215 19 8 25 4 21 1 206 22.0 26 2 25.2 28.1 19.1 18.0 21.0 25.1 22.7 30.3 19.6 19.4 20.1 22.3 21.8 23.2 Blue-collar total 19.8 19.9 19.4 23.3 22.6 25.1 Craftsmen and kindred workers Operatives and kindred workers Laborers, except farm 22.4 22.3 22.5 24.4 23.7 26.1 18.4 22.4 21.7 24.2 25.6 21.5 23.6 service 18.9 21.5 24.7 Farm 19.2 18.9 19.0 18.0 21.2 19.4 19.5 18.1 19.0 18.0 21.2 19.4 18.0 Unemployed Usual activity, homemaking 20.9 215 - 20.9 19.9 20.2 20.1 - 21.7 21.3 26 0 19.4 SOURCE: Natmnal Center for Health Statistln, ?iational Health Internew Surveys. 1978-1980 icomblnedl. (See Technical Addendum.1 to report a higher percentage of heavy smokers than their 20- to 44- year-old counterparts. Age of Initiation Men employed as blue-collar workers initiate smoking approxi- mately 14 months earlier, on the average, than men employed in white-collar occupations (Table 8). The earliest ages of initiation are 29 TABLE 6.-Estimates of the percentage of current smokers who smoke more than 20 or more than 40 cigarettes daily, by age and occupation, men, aged 20 to 64 years, United States, 1978-1980 Total 20.44 45-64 Occupation 220 >a 220 240 220 240 Total 70.6 18.8 66.5 15.7 74.8 24.5 Currently employed 71.4 19.1 69.3 16.1 76.0 25.7 Whit&collar total 72.1 21.1 69.5 16.9 77.6 29.5 Professional, technical, and kindred workers Managers and administrators, except farm Sales workers Clerical and kindred workers 66.5 17.3 61.9 12.9 76.7 26.8 79.1 24.5 77.7 20.0 81.6 33.3 74.2 23.7 70.0 17.8 83.0 36.1 64.2 17.2 64.1 16.2 64.6 19.0 Blue-collar total 11.8 18.3 70.1 16.1 76.3 24.1 Craftsmen and kindred workers Operatives and kindred workers Lalmers. except farm 75.3 21.2 73.6 18.7 79.6 27.2 694 15.6 68.3 13.5 72.1 21.4 65.7 15.1 63.1 14.2 74.6 17.9 Service 66.6 16.0 63.0 11.5 73.6 24.7 Farm 62.1 16.5 56.3 ' 16.6 ' 16.4 ' Unemployed 65.9 16.3 61.3 12.9 68.0 ' 81.1 ' - 27.6 ' Usual actwlty. homemakmg - - - - ' i 1W cases in the denominator lunwelghted sample). SOURCE Natmnal Center for Health Statistics. Natmnal Health lnterv~ew Surveys. 197&1980 icombined &e Techmcal Addendum 1 reported by men employed as laborers (16.5 years), operatives or kindred workers (16.6 years), or craftsmen or kindred workers (16.8 years). Men employed in professional, technical, or kindred occupa- tions, or as managers or administrators, sales workers, or clerical or kindred workers report later onset of smoking, ranging between 17.7 and 18.1 years of age. For women, blue-collar and service workers report a somewhat earlier onset of smoking than white-collar workers or homemakers 30 TABLE `I.-Estimates of the percentage of current smokers who smoke more than 20 or more than 40 cigarettes daily, by age and occupation, women, aged 20 to 64 years, United States, 1978-1980 Total 20-44 45-64 Occupation 2 20 _> 40 > 20 140 120 240 Total 58.6 114 57.1 10.8 61.3 12.4 Currently employed 58.5 113 57.2 10.9 61.7 12.3 White-collar total 59.4 118 57.8 11.0 63.2 13.8 Professional. technical, and kindred workers Managers and administrators. except farm Sales workers Clerical and kindred workers 52 8 10 8 52.0 9.8 55.0 1B.8 63.4 15.6 59.0 14.6 71.8 17.5 56.8 99 55.0 6.5 59.9 * 16.0 o 61.6 11.5 60.6 11.3 11.5 18.2 * 10.5 50' 11.9 5.5 ' 14.4 10.9 643 12.0 Blue-collar total 62.0 11.2 61.2 64.0 10.6 Craftsmen and kindred workers Operatives and kindred workers Laborers, except farm 70.0 18 2 67.4 * 75.5 * 18.1' 60.4 99 60.3 60.7 8.4 56.7 ' 6.0 * 55.2 ' 70.9 * 15.6 o Service FarIll 54.6 11.6 53.6 57 1 65.4 ' 4.9 ' 14.8 113 63.5 ' 802' Unemployed 62.1 61.7 64 4 * Usual activity. homemaking 59.1 58.4 60.0 11.0 0.0 * 17.0 o 11.8 * s: 100 cases in the denommator iunweighti samplel SOURCE. National Center far Health Statmtics Natmnal Health Inrerwew Surveys. 197%1980 lcombmedi (See Technical Addendum 1 (about 6 months). The earliest age of initiation occurs among women employed as laborers (17.4 years of age) or operatives or kindred workers (18.5 years of age), and the latest age of initiation occurs among women employed in professional, technical, or kindred occupations (19.4 years of age). Across all occupational categories, men report an earlier age of initiation than women; this difference is most pronounced within the 45 to 64 age group. 31 TABLE %-Estimates of average age of initiation of smoking among current and former smokers by sex, age, and occupation, aged 20 to 64 years, United States, 1978-1980 0ccupat10n Women Men Total 2M4 45-64 Total 2b44 45-64 Total Currently employed White-collar total Professional. technical, and kindred workers Managers and administrators, except farm Sales workers Clerical and kindred workers Blue-collar total Craftsmen and kindred workers Operatives and kindred workers Laborers, except farm Service Farm Unemployed Usual act1wty. homemaking i9.0 18.6 18.5 18 2 18.1 18.0 18.2 17.6 17.6 21.2 21 .o 20.9 21.2 20.7 21.2 20.9 21.3 22.9 21.1 16.5 21.4 18.4 21.1 21.3 17.2 17.3 17.9 18.1 17.8 17.8 17.7 16.7 16.8 16.6 16.5 17.2 17.0 169 16.9 17.0 17.6 17.6 17.5 16.5 16.5 16.4 16.4 169 16.4 16 4 17 6 18.7 18.0 18.4 18.2 SOURCE Natmnal Center for Health Statistics. Natmnal Health Interview Surveys. 197&1980 tcombinedl.