The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General, U.S. Department of Health and Human Services

Secondhand Smoke Exposure in the Home

  • The home is the place where children are most exposed to secondhand smoke and a major location of secondhand smoke exposure for adults.

  • Children who live in homes where smoking is allowed have higher levels of cotinine (a biological marker of secondhand smoke exposure) than children who live in homes where smoking is not allowed. As the number of cigarettes smoked in the home increases, children’s cotinine levels rise.

  • Although secondhand smoke exposure among children has declined over the past 15 years, children remain more heavily exposed to secondhand smoke than adults.

    • Almost 60 percent of U.S. children aged 3-11 years—or almost 22 million children—are exposed to secondhand smoke.

    • 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.

  • Secondhand smoke exposure in the home has been consistently linked to a significant increase in both heart disease and lung cancer risk among adult nonsmokers.

  • According to the Census Bureau’s Current Population Survey, the proportion of households with smoke-free home rules increased from 43 percent in 1992-93 to 66 percent in 2001-02.

  • The proportion of persons who are covered by smoke-free home rules varies somewhat by region and state. For example, as of 2001-2002 this figure ranged from 51 percent in Kentucky to 86 percent in Utah among residents aged 15 years and older.

  • The Surgeon General has concluded that eliminating smoking in indoor spaces is the only way to fully protect nonsmokers from secondhand smoke exposure. Separating smokers from nonsmokers, cleaning the air, and ventilating buildings cannot completely eliminate secondhand smoke exposure.

  • Smoke-free rules in homes and vehicles can reduce secondhand smoke exposure among children and nonsmoking adults. Some studies indicate that these rules can also help smokers quit and can reduce the risk of adolescents becoming smokers.

Information contained on this highlight sheet has been taken directly from The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General. For more information, please refer to the Resources and How to Protect Yourself and Your Loved Ones from Secondhand Smoke highlight sheets. Additional highlight sheets are also available at

Last revised: January 4, 2007