How Tobacco Smoke Causes Disease

This report considers the biological and behavioral mechanisms that may underlie the pathogenicity of tobacco smoke. Many Surgeon General's reports have considered research findings on mechanisms in assessing the biological plausibility of associations observed in epidemiologic studies. Mechanisms of disease are important because they may provide plausibility, which is one of the guideline criteria for assessing evidence on causation. This report specifically reviews the evidence on the potential mechanisms by which smoking causes diseases and considers whether a mechanism is likely to be operative in the production of human disease by tobacco smoke. This evidence is relevant to understanding how smoking causes disease, to identifying those who may be particularly susceptible, and to assessing the potential risks of tobacco products.

This Surgeon General's report returns to the topic of the health effects of involuntary exposure to tobacco smoke. The last comprehensive review of this evidence by the Department of Health and Human Services (DHHS) was in the 1986 Surgeon General's report, The Health Consequences of Involuntary Smoking, published 20 years ago this year. This new report updates the evidence of the harmful effects of involuntary exposure to tobacco smoke. This large body of research findings is captured in an accompanying dynamic database that profiles key epidemiologic findings, and allows the evidence on health effects of exposure to tobacco smoke to be synthesized and updated (following the format of the 2004 report, The Health Consequences of Smoking). The database enables users to explore the data and studies supporting the conclusions in the report. The database is available on the Web site of the Centers for Disease Control and Prevention (CDC) at http://www.cdc.gov/tobacco.

This report considers the biological and behavioral mechanisms that may underlie the pathogenicity of tobacco smoke. Many Surgeon General's reports have considered research findings on mechanisms in assessing the biological plausibility of associations observed in epidemiologic studies. Mechanisms of disease are important because they may provide plausibility, which is one of the guideline criteria for assessing evidence on causation. This report specifically reviews the evidence on the potential mechanisms by which smoking causes diseases and considers whether a mechanism is likely to be operative in the production of human disease by tobacco smoke. This evidence is relevant to understanding how smoking causes disease, to identifying those who may be particularly susceptible, and to assessing the potential risks of tobacco products.

Smoking causes and contributes to a large number of human diseases, yet due to the large number of potentially hazardous compounds in cigarette smoke -- almost 5,000 chemicals have been identified, establishing the link between smoking and disease has often proved difficult. This unbiased and scientifically accurate overview of current knowledge begins with an overview of the chemical constituents in cigarette smoke, their fate in the human body, and their documented toxic effects on various cells and tissues. Recent results detailing the many ways components of cigarette smoke adversely affect human health are also presented, highlighting the role of smoking in cardiovascular, respiratory, infectious and other diseases. A final chapter discusses current strategies for the treatment and prevention of smoking-induced illness. Despite the obvious importance of the topic, this is the first comprehensive reference on tobacco smoke toxicity, making for essential reading for all toxicologists and healthcare professionals dealing with smoking-related diseases.

"Science tends to generalize, and generaliza tions mean simplifications . . . . And generaliza tions are also more satisfying to the mind than details. Of course, details and generalizations must be in proper balance: Generalizations can be reached only from details, while it is the generalization which gives value and interest to the detail:' . . . (A. Szent-Gyorgy, Science 1964) The first edition of this book, published in German as Tabak abhiingigkeit in 2001, was prompted by the fact that no single volume was available in Germany or elsewhere summarising the adverse repercussions of cigarette smoking on human health. As far as my own research was able to ascertain, the last comprehensive work dealing with this subject was writ ten in Germany by the Dresden internist, F. Lickint, whose Tabak und Organismus was published in 1939 by the Hip pokrates-Verlag. All subsequent monographs in this field have tended to focus on detailed aspects, and there has been no shortage of publications on subjects such as how smokers can quit smoking, healthy eating for smokers etc. Friends and colleagues abroad have urged me to prepare an English language version of Tabakabhiingigkeit. In gladly complying with this suggestion, I have intentionally prepared an up dated and slightly enlarged new edition, taking account of the rapidly proliferating literature on the subject up to the start of 2002. The harmful sequelae of smoking are played down by politicians in many industrialised countries, including Ger many.

Cardiovascular, respiratory, and related conditions cause more than 40 percent of all deaths globally, and their substantial burden is rising, particularly in low- and middle-income countries (LMICs). Their burden extends well beyond health effects to include significant economic and societal consequences. Most of these conditions are related, share risk factors, and have common control measures at the clinical, population, and policy levels. Lives can be extended and improved when these diseases are prevented, detected, and managed. This volume summarizes current knowledge and presents evidence-based interventions that are effective, cost-effective, and scalable in LMICs.

Data suggest that exposure to secondhand smoke can result in heart disease in nonsmoking adults. Recently, progress has been made in reducing involuntary exposure to secondhand smoke through legislation banning smoking in workplaces, restaurants, and other public places. The effect of legislation to ban smoking and its effects on the cardiovascular health of nonsmoking adults, however, remains a question. Secondhand Smoke Exposure and Cardiovascular Effects reviews available scientific literature to assess the relationship between secondhand smoke exposure and acute coronary events. The authors, experts in secondhand smoke exposure and toxicology, clinical cardiology, epidemiology, and statistics, find that there is about a 25 to 30 percent increase in the risk of coronary heart disease from exposure to secondhand smoke. Their findings agree with the 2006 Surgeon General's Report conclusion that there are increased risks of coronary heart disease morbidity and mortality among men and women exposed to secondhand smoke. However, the authors note that the evidence for determining the magnitude of the relationship between chronic secondhand smoke exposure and coronary heart disease is not very strong. Public health professionals will rely upon Secondhand Smoke Exposure and Cardiovascular Effects for its survey of critical epidemiological studies on the effects of smoking bans and evidence of links between secondhand smoke exposure and cardiovascular events, as well as its findings and recommendations.

In 1964, the first Surgeon General's report on the effects of smoking on health was released. In the nearly 50 years since, extensive data from thousands of studies have consistently substantiated the devastating effects of smoking on the lives of millions of Americans. Now, this 2010 report of the Surgeon General explains beyond a shadow of a doubt how tobacco smoke causes disease, validates earlier findings, and expands and strengthens the science base. Armed with this irrefutable data, the time has come to mount a full-scale assault on the tobacco epidemic. More than 1,000 people are killed every day by cigarettes, and one-half of all long-term smokers are killed by smoking-related diseases. A large proportion of these deaths are from early heart attacks, chronic lung diseases, and cancers. Every year, thousands of nonsmokers die from heart disease and lung cancer, and hundreds of thousands of children suffer from respiratory infections because of exposure to secondhand smoke. There is no risk-free level of exposure to tobacco smoke, and there is no safe tobacco product. This new Surgeon General's report describes in detail the ways tobacco smoke damages every organ in the body and causes disease and death. We must build on our successes and more effectively educate people about the health risks of tobacco use, prevent youth from ever using tobacco products, expand access to proven cessation treatments and services, and reduce exposure to secondhand smoke. Putting laws and other restrictions in place, including making tobacco products progressively less affordable, will ultimately lead to our goal of a healthier America by reducing the devastating effects of smoking. The Centers for Disease Control and Prevention (CDC), the U.S. Food and Drug Administration (FDA), and other federal agencies are diligently working toward this goal by implementing and sup¬porting policies and regulations that strengthen our resolve to end the tobacco epidemic. CDC has incorporated the World Health Organization's MPOWER approach into its actions at the local, state, and national levels. MPOWER consists of six key interventions proven to reduce tobacco use that can prevent millions of deaths. CDC, along with federal, state, and local partners, is committed to monitor¬ing the tobacco epidemic and prevention policies; protecting people from secondhand smoke where they live, work, and play; offering quit assistance to current smokers; warning about the dangers of tobacco; enforcing comprehensive restrictions on tobacco advertising, promotion, and sponsorship; and raising taxes and prices on tobacco products.In 2009, the Family Smoking Prevention and Tobacco Control Act was enacted, giving FDA explicit regulatory authority over tobacco products to protect and promote the health of the American public. Among other things, this historic legislation gave the agency the authority to require companies to reveal all of the ingredients in tobacco products—including the amount of nicotine—and to prohibit the sale of tobacco products labeled as “light,” “mild,” or “low.” Further, with this new regulatory mandate, FDA will regulate tobacco advertising and require manufacturers to use more effective warning labels, as well as restrict the access of young people to their products. FDA will also assess and regulate modified risk products, taking into account the impact their availability and marketing has on initiation and cessation of tobacco use. This 2010 Surgeon General's report represents another important step in the developing recognition, both in this nation and around the world, that tobacco use is devastating to public health. Past investments in research and in comprehensive tobacco control programs—combined with the findings presented by this new report—provide the foundation, evidence, and impetus to increase the urgency of our actions to end the epidemic of tobacco use.