What is Second Hand Smoke and Why is it Bad for You

• Secondhand smoke, also known as environmental tobacco smoke, is a complex mixture of gases and particles that includes smoke from the burning cigarette, cigar, or pipe tip (sidestream smoke) and exhaled mainstream smoke.¹
   
• Secondhand smoke is a known human carcinogen (cancer-causing agent). More than 50 compounds in secondhand smoke have been identified as known or reasonably anticipated human carcinogens. Secondhand smoke contains at least 250 chemicals that are known to be toxic or carcinogenic.¹
   
• People are exposed to secondhand smoke in homes, vehicles, workplaces, and in public places such as restaurants, bars, and casinos. Homes and workplaces are the predominant locations for secondhand smoke exposure.²
   

Health Effects

• Secondhand smoke exposure causes heart disease and lung cancer in nonsmoking adults. Nonsmokers who are exposed to secondhand smoke at home or work increase their heart disease risk by 25–30 percent and their lung cancer risk by 20–30 percent.² Secondhand smoke exposure has immediate adverse effects on the cardiovascular system.²
   
• Secondhand smoke causes sudden infant death syndrome (SIDS), acute respiratory infections, ear problems, and more frequent and severe asthma attacks in children. Secondhand smoke exposure causes respiratory symptoms in children and slows their lung growth.²
   
• There is no risk-free level of secondhand smoke exposure. Even brief exposure can be dangerous.²
   

Current Estimates

• Levels of a chemical called cotinine, which is a marker of exposure to nicotine and secondhand smoke in nonsmokers, fell by 70 percent from 1988-91 to 2001-02. Over this same time period, the proportion of nonsmokers with detectable cotinine levels was halved from 88 percent to 43 percent.³
   
• More than 126 million nonsmoking Americans continue to be exposed to secondhand smoke in homes, vehicles, workplaces, and public places.²
   
• Almost 60 percent of U.S. children aged 3–11 years—or almost 22 million children—are exposed to secondhand smoke.²
   
• About 25 percent of children aged 3-11 years live with at least one smoker, as compared to only about 7 percent of nonsmoking adults.²
   
• The California Environmental Protection Agency estimates that secondhand smoke exposure causes approximately 3,400 lung cancer deaths and 22,700–69,600 heart disease deaths annually among adult nonsmokers in the United States.⁴
   
• Secondhand smoke exposure is responsible for an estimated 150,000–300,000 new cases of bronchitis and pneumonia in children aged less than 18 months, resulting in 7,500–15,000 hospitalizations.⁵
   

References

1. National Toxicology Program. 9th Report on Carcinogens, 2000. Research Triangle Park, NC: U.S. Department of Health and Human Sciences, National Institute of Environmental Health Sciences, 2000. http://ntp.niehs.nih.gov/ntp/roc/eleventh/profiles/s176toba.pdf ( PDF–219K). Accessed June 2006.
    
2. U.S. Department of Health and Human Services. The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General. Atlanta, Georgia: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, Coordinating Center for Health Promotion, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, 2006.
   http://www.surgeongeneral.gov/library/secondhandsmoke/report/
    
3. Pirkle JL, Bernert JT, Caudill SP, Sosnoff CS, Pechacek TF. Trends in the exposure of nonsmokers in the U.S. population to secondhand smoke: 1988–2002. Environmental Health Perspectives 2006; 114(6):853–858.
    
4. California Environmental Protection Agency. Proposed Identification of Environmental Tobacco Smoke as a Toxic Air Contaminant. California Environmental Protection Agency, final report, September 29, 2005, approved by Scientific Review Panel on June 24, 2005. http://www.arb.ca.gov/toxics/ets/finalreport/finalreport.htm. Accessed June 2006.
    
5. United States Environmental Protection Agency (EPA). Respiratory Health Effects of Passive Smoking: Lung Cancer and Other Disorders. Office of Research and Development, EPA/600/6-90/006F, Washington, D.C., December 1992. http://cfpub2.epa.gov/ncea/cfm/recordisplay.cfm?deid=2835. Accessed June 2006.
    
   Also published as: National Institutes of Health. National Cancer Institute. Respiratory Health Effects of Passive Smoking: Lung Cancer and Other Disorders: The Report of the U.S. Environmental Protection Agency. Smoking and Tobacco Control Monograph Number 4. NIH Publication No. 93-3605, Washington, D.C., August 1993.

Note: More recent information may be available at the CDC'S Office on Smoking and Health Web site: http://www.cdc.gov/tobacco.

Smoking 101 Fact Sheet

March 2006 Cigarette smoking has been identified as the most important source of preventable morbidity and premature mortality worldwide. Smoking-related diseases claim an estimated 438,000 American lives each year, including those affected indirectly, such as babies born prematurely due to prenatal maternal smoking and victims of "secondhand" exposure to tobacco's carcinogens. Smoking costs the United States over $167 billion each year in health-care costs including $92 billion in mortality-related productivity loses and $75.5 billion in excess medical expenditures.1 Cigarette smoke contains over 4,800 chemicals, 69 of which are known to cause cancer. Smoking is directly responsible for approximately 90 percent of lung cancer deaths and approximately 80-90 percent of COPD (emphysema and chronic bronchitis) deaths.2  About 8.6 million people in the U.S. have at least one serious illness caused by smoking. That means that for every person who dies of a smoking-related disease, there are 20 more people who suffer from at least one serious illness associated with smoking.3 Among current smokers, chronic lung disease accounts for 73 percent of smoking-related conditions. Even among smokers who have quit chronic lung disease accounts for 50 percent of smoking-related conditions.4 Smoking is also a major factor in coronary heart disease and stroke; may be causally related to malignancies in other parts of the body; and has been linked to a variety of other conditions and disorders, including slowed healing of wounds, infertility, and peptic ulcer disease. For the first time, the Surgeon General includes pneumonia in the list of diseases caused by smoking.5 Smoking in pregnancy accounts for an estimated 20 to 30 percent of low-birth weight babies, up to 14 percent of preterm deliveries, and some 10 percent of all infant deaths. Even apparently healthy, full-term babies of smokers have been found to be born with narrowed airways and curtailed lung function.6  Only about 30 percent of women who smoke stop smoking when they find out they are pregnant; the proportion of quitters is highest among married women and women with higher levels of education.  Smoking during pregnancy declined in 2003 to 10.7 percent of women giving birth, down 42 percent from 1990.7 Neonatal health-care costs attributable to maternal smoking in the U.S. have been estimated at $366 million per year, or $704 per maternal smoker.8 Smoking by parents is also associated with a wide range of adverse effects in their children, including exacerbation of asthma, increased frequency of colds and ear infections, and sudden infant death syndrome. Secondhand smoke causes an estimated 150,000 to 300,000 cases of lower respiratory tract infections in children less than 18 months of age, resulting in 7,500 to 15,000 annual hospitalizations.9 In 2004, an estimated 44.5 million, or 20.9 percent of, adults were current smokers.  The annual prevalence of smoking has declined 40 percent between 1965 and 1990, but has been unchanged virtually thereafter.10 Males tend to have significantly higher rates of smoking prevalence than females.  In 2004, 23.4 percent of males currently smoked compared to 18.5 percent of females.11 Prevalence of current smoking in 2004 was highest among Native American Indians/Alaskan Natives (33.4%), intermediate among non-Hispanic whites (22.2%), and non-Hispanic blacks (20.2%), and lowest among Hispanics (15%) and Asians and Pacific Islanders (11.3%).12  As smoking declines among the White non-Hispanic population, tobacco companies have targeted both African Americans and Hispanics with intensive merchandising, which includes billboards, advertising in media targeted to those communities, and sponsorship of civic groups and athletic, cultural, and entertainment events. In 2003, total advertising and promotion by the five major tobacco companies was the highest ever reported at $15.5 billion.13  Tobacco advertising also plays an important role in encouraging young people to begin a lifelong addiction to smoking before they are old enough to fully understand its long-term health risk. Approximately 90 percent of smokers begin smoking before the age of 21.14 In 2004, 22 percent of high school students were current smokers. Over 8 percent of middle school students were current smokers in 2004.15.16 Secondhand smoke involuntarily inhaled by nonsmokers from other people's cigarettes is classified by the U.S. Environmental Protection Agency as a known human (Group A) carcinogen, responsible for approximately 3,000 lung cancer deaths annually in U.S. nonsmokers.17 Workplaces nationwide are going smoke-free to provide clean indoor air and protect employees from the life-threatening effects of secondhand smoke. Nearly 70 percent of the U.S. workforce worked under a smoke free policy in 1999, but the percentage of workers protected varies by state, ranging from a high of 83.9 percent in Utah to 48.7% in Nevada.18 Employers have a legal right to restrict smoking in the workplace, or implement a totally smoke-free workplace policy.  Exceptions may arise in the case of collective bargaining agreements with unions. Nicotine is an addictive drug, which when inhaled in cigarette smoke reaches the brain faster than drugs that enter the body intravenously. Smokers not only become physically addicted to nicotine; they also link smoking with many social activities, making smoking a difficult habit to break.19 In 2003, an estimated 45.9 million adults were former smokers. Of the current 44.5 million smokers, more than 32 million persons reported they wanted to quit smoking completely.20   Nicotine replacement products can help relieve withdrawal symptoms people experience when they quit smoking. Nicotine patches, nicotine gum and nicotine lozenges are available over-the-counter, and a nicotine nasal spray and inhaler, as well as a non-nicotine pill, are currently available by prescription.21  Nicotine replacement therapies are helpful in quitting when combined with a behavior change program such as the American Lung Association's Freedom From Smoking (FFS), which addresses psychological and behavioral addictions to smoking and strategies for coping with urges to smoke.