Secondhand Smoke (SHS) Facts

Secondhand smoke harms children and adults, and the only way to fully protect nonsmokers is to eliminate smoking in all homes, worksites, and public places.^1,2,3

You can take steps to protect yourself and your family from secondhand smoke, such as making your home and vehicles smokefree.^2,3

Separating smokers from nonsmokers, opening windows, or using air filters does not prevent people from breathing secondhand smoke.^1,2,3

Most exposure to secondhand smoke occurs in homes and workplaces.^2,3

People are also exposed to secondhand smoke in public places—such as in restaurants, bars, and casinos—as well as in cars and other vehicles.^2,3

People with lower income and lower education are less likely to be covered by smokefree laws in worksites, restaurants, and bars.⁴

What Is Secondhand Smoke?

• Secondhand smoke is smoke from burning tobacco products, such as cigarettes, cigars, or pipes.^1,5,6
• Secondhand smoke also is smoke that has been exhaled, or breathed out, by the person smoking.^5,6
• Tobacco smoke contains more than 7,000 chemicals, including hundreds that are toxic and about 70 that can cause cancer.¹

Secondhand Smoke Harms Children and Adults

Smokefree laws can reduce the risk for heart disease and lung cancer among nonsmokers.¹

Patterns of Secondhand Smoke Exposure

Exposure to secondhand smoke can be measured by testing saliva, urine, or blood to see if it contains cotinine.³ Cotinine is created when the body breaks down the nicotine found in tobacco smoke.

Secondhand Smoke Exposure Has Decreased in Recent Years

• Measurements of cotinine show that exposure to secondhand smoke has steadily decreased in the United States over time.
  • During 1988–1991, almost 90 of every 100 (87.9%) nonsmokers had measurable levels of cotinine.⁷
  • During 2007–2008, about 40 of every 100 (40.1%) nonsmokers had measurable levels of cotinine.⁷
  • During 2011–2012, about 25 of every 100 (25.3%) nonsmokers had measurable levels of cotinine.⁸

• The decrease in exposure to secondhand smoke is likely due to:⁸
  • The growing number of states and communities with laws that do not allow smoking in indoor areas of workplaces and public places, including restaurants, bars, and casinos
  • The growing number of households with voluntary smokefree home rules
  • Significant declines in cigarette smoking rates
  • The fact that smoking around nonsmokers has become much less socially acceptable

Many People in the United States Are Still Exposed to Secondhand Smoke

• During 2011–2012, about 58 million nonsmokers in the United States were exposed to secondhand smoke.⁸
• Among children who live in homes in which no one smokes indoors, those who live in multi-unit housing (for example, apartments or condos) have 45% higher cotinine levels (or almost half the amount) than children who live in single-family homes.⁹
• During 2011–2012, 2 out of every 5 children ages 3 to 11—including 7 out of every 10 Black children—in the United States were exposed to secondhand smoke regularly.⁸
• During 2011–2012, more than 1 in 3 (36.8%) nonsmokers who lived in rental housing were exposed to secondhand smoke.⁸

Differences in Secondhand Smoke Exposure

Income⁸

• Secondhand smoke exposure is higher among people with low incomes.
• During 2011–2012, more than 2 out of every 5 (43.2%) nonsmokers who lived below the poverty level were exposed to secondhand smoke.

Occupation¹⁰

• Differences in secondhand smoke exposure related to people’s jobs decreased over the past 20 years, but large differences still exist.
• Some groups continue to have high levels of secondhand smoke exposure. These include:
  • Blue-collar workers and service workers
  • Construction workers

What You Can Do

You can protect yourself and your family from secondhand smoke by:^2,3,4

• Quitting smoking if you are not already a nonsmoker
• Not allowing anyone to smoke anywhere in or near your home
• Not allowing anyone to smoke in your car, even with the windows down
• Making sure your children’s day care center and schools are tobacco-free
• Seeking out restaurants and other places that do not allow smoking (if your state still allows smoking in public areas)
• Teaching your children to stay away from secondhand smoke
• Being a good role model by not smoking or using any other type of tobacco

References

1. U.S. Department of Health and Human Services. The Health Consequences of Smoking—50 Years of Progress: A Report of the Surgeon General. Atlanta: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, 2014 [accessed 2017 Feb 21].
2. U.S. Department of Health and Human Services. A Report of the Surgeon General: How Tobacco Smoke Causes Disease: What It Means to You. Atlanta: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, 2010 [accessed 2017 Feb 21].
3. U.S. Department of Health and Human Services. The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General. Atlanta: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, 2006 [accessed 2017 Feb 21].
4. Huang J, King BA, Babb SD, Xu X, Hallett C, Hopkins M. Sociodemographic Disparities in Local Smoke-Free Law Coverage in 10 States. American Journal of Public Health 2015;105(9):1806–13 [cited 2017 Feb 21].
5. Institute of Medicine. Secondhand Smoke Exposure and Cardiovascular Effects: Making Sense of the Evidence. Washington: National Academy of Sciences, Institute of Medicine, 2009 [accessed 2017 Feb 21].
6. National Toxicology Program. Report on Carcinogens, Fourteenth Edition. Research Triangle Park (NC): U.S. Department of Health and Human Services, Public Health Service, 2016 [accessed 2017 Feb 21].
7. Centers for Disease Control and Prevention. Vital Signs: Nonsmokers’ Exposure to Secondhand Smoke—United States, 1999–2008. Morbidity and Mortality Weekly Report 2010;59(35):1141–6 [accessed 2017 Feb 21].
8. Centers for Disease Control and Prevention. Vital Signs: Disparities in Nonsmokers’ Exposure to Secondhand Smoke—United States, 1999–2012. Morbidity and Mortality Weekly Report 2015;64(4):103–8 [accessed 2017 Feb 21].
9. Wilson KM, Klein JD, Blumkin AK, Gottlieb M, Winickoff JP.Tobacco Smoke Exposure in Children Who Live in Multiunit Housing. [PDF–575 KB] Pediatrics 2011:127(1):85-92 [accessed 2017 Feb 21].
10. Arheart KL, Lee DJ, Dietz NA, Wilkinson JD, Clark III JD, LeBlanc WG, Serdar B, Fleming LE. Declining Trends in Serum Cotinine Levels in U.S. Worker Groups: The Power of Policy. Journal of Occupational and Environmental Medicine 2008;50(1):57–63 [cited 2017 Feb 21].