Smoking can cause—and provide ongoing support to—cancer and other diseases. Secondhand smoke and third hand smoke are also significant threats to quality of life and survival.

Cigarette smoking is the leading cause of preventable disease and death in the United States, accounting for more than 480,000 deaths every year, or 1 of every 5 deaths.¹ In 2015, about 15 of every 100 U.S. adults aged 18 years or older (15.1%) currently* smoked cigarettes. This means an estimated 36.5 million adults in the United States currently smoke cigarettes.² More than 16 million Americans live with a smoking-related disease.² Current smoking has declined from nearly 21 of every 100 adults (20.9%) in 2005 to about 15 of every 100 adults (15.1%) in 2015.²

Secondhand smoke and third hand smoke also provides harm, compromising health and supporting disease, including to death.

Secondhand smoke (also called environmental tobacco smoke, involuntary smoking, and passive smoking) is the combination of “sidestream” smoke (the smoke given off by a burning tobacco product) and “mainstream” smoke (the smoke exhaled by a smoker)^{7, 8, 9, 10}. The U.S. Environmental Protection Agency, the U.S. National Toxicology Program, the U.S. Surgeon General, and the International Agency for Research on Cancer have classified secondhand smoke as a known human carcinogen, which is a cancer-causing agent^{8, 10, 11}.

More than 7000 chemicals are created by secondhand smoke, and at least 250 are known to be harmful. Research indicates that hundreds are toxic, and about 70 can cause cancer.^3,4,5,6 Some studies demonstrate increases in cancer, heart disease, and other conditions. Learn more in CDC’s Health Effects of Secondhand Smoke.

Third hand smoke is an invisible, toxic combination of gases and particles that clings to a smoker’s hair, clothing, furniture, carpeting, and other items. The residue of third hand smoke contains heavy metals, carcinogens, and radioactive materials.

Quit the habit of smoking, and being exposed to smoke, to improve quality of life and cancer survival.

For More Information

• National Cancer Institute (NCI) Smoking
• NCI’s Smoking Quitline at 1-877-44U-QUIT and LiveHelp can talk with you about ways to quit smoking and groups that help smokers who want to quit. Groups may offer counseling in person or by telephone.
• Smoke Free, a federal government resource, has an online guide to quitting smoking and a list of other resources.
• Centers for Disease Control and Prevention Smoking and Tobacco Use
• Doctors and dentists can help their patients find local programs or trained professionals who help people stop using tobacco.
• Doctors and dentists can suggest medicine or nicotine replacement therapy, such as a patch, gum, lozenge, nasal spray, or inhaler.

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 2016 Nov 14].
2. Centers for Disease Control and Prevention. Cigarette Smoking Among Adults-United States, 2005-2015. Morbidity and Mortality Weekly Report 2016;65(44):1205-11 [accessed 2016 Nov 14].
3. U.S. Department of Health and Human Services. Let’s Make the Next Generation Tobacco-Free: Your Guide to the 50th Anniversary Surgeon General’s Report on Smoking and Health. [PDF–795 KB] 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 2016 Jan 11].
4. 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 Jan 11].
5. 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 Jan 11].
6. 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 Jan 11].
7. U.S. Department of Health and Human Services. The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General. Rockville, MD: 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.
8. National Toxicology Program. Report on Carcinogens. Thirteenth Edition. U.S. Department of Health and Human Services, Public Health Service, National Toxicology Program, 2014.
9. National Cancer Institute. Cancer Trends Progress Report: Secondhand Smoke. National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, MD, March 2015.
10. International Agency for Research on Cancer. Tobacco SmokingExit Disclaimer, Second-hand Tobacco SmokeExit Disclaimer, and Smokeless TobaccoExit Disclaimer. Lyon, France: 2012. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol. 100E.
11. U.S. Environmental Protection Agency (November 30, 2011). Health Effects of Exposure to Secondhand Smoke. Retrieved September 2, 2014, from:  http://www.epa.gov/smokefree/healtheffects.html.