Health Effects of Secondhand Smoke

Overview

Secondhand smoke is the combination of smoke from the burning end of a cigarette and the smoke breathed out by smokers. Secondhand smoke contains more than 7000 chemicals. Hundreds are toxic and about 70 can cause cancer.^1,2

There is no risk-free level of exposure to secondhand smoke. Secondhand smoke causes numerous health problems in infants and children, including severe asthma attacks, respiratory infections, ear infections, and sudden infant death syndrome (SIDS).¹ Some of the health conditions caused by secondhand smoke in adults include heart disease and lung cancer.¹

Secondhand Smoke Causes Heart Disease

Exposure to secondhand smoke has immediate adverse effects on the cardiovascular system and can cause coronary heart disease.^1,3

• Secondhand smoke causes an estimated 46,000 premature deaths from heart disease each year in the United States among nonsmokers.⁴
• Nonsmokers who are exposed to secondhand smoke at home or at work increase their risk of developing heart disease by 25–30%.¹

Breathing secondhand smoke can have immediate adverse effects on your blood and blood vessels, increasing the risk of having a heart attack.^1,2

• Breathing secondhand smoke interferes with the normal functioning of the heart, blood, and vascular systems in ways that increase the risk of having a heart attack.
• Even brief secondhand smoke exposure can damage the lining of blood vessels and cause your blood platelets to become stickier. These changes can cause a deadly heart attack.

People who already have heart disease are at especially high risk of suffering adverse effects from breathing secondhand smoke and should take special precautions to avoid even brief exposures.¹

Secondhand Smoke Causes Lung Cancer

Secondhand smoke causes lung cancer in adults who themselves have never smoked.¹

• Nonsmokers who are exposed to secondhand smoke at home or at work increase their risk of developing lung cancer by 20–30%.¹
• Secondhand smoke causes an estimated 3,400 lung cancer deaths among U.S. nonsmokers each year.^4,5

Nonsmokers who are exposed to secondhand smoke are inhaling many of the same cancer-causing substances and poisons as smokers.^1,2

• Secondhand smoke contains about 70 cancer-causing chemicals.
• Even brief secondhand smoke exposure can damage cells in ways that set the cancer process in motion.
• As with active smoking, the longer the duration and the higher the level of exposure to secondhand smoke, the greater the risk of developing lung cancer.

Secondhand Smoke Causes SIDS

SIDS is the sudden, unexplained, unexpected death of an infant in the first year of life. SIDS is the leading cause of death in otherwise healthy infants.⁶ Secondhand smoke increases the risk for SIDS.¹

• Smoking by women during pregnancy increases the risk for SIDS.⁷
• Infants who are exposed to secondhand smoke after birth are also at greater risk for SIDS.¹
• Chemicals in secondhand smoke appear to affect the brain in ways that interfere with its regulation of infants' breathing.¹
• Infants who die from SIDS have higher concentrations of nicotine in their lungs and higher levels of cotinine (a biological marker for secondhand smoke exposure) than infants who die from other causes.¹

Parents can help protect their babies from SIDS by taking the following three actions:⁸

• Do not smoke when pregnant.
• Do not smoke in the home or around the baby.
• Put the baby down to sleep on its back.

Secondhand Smoke and Children

Secondhand smoke can cause serious health problems in children.⁹

• Studies show that older children whose parents smoke get sick more often. Their lungs grow less than children who do not breathe secondhand smoke, and they get more bronchitis and pneumonia.
• Wheezing and coughing are more common in children who breathe secondhand smoke.
• Secondhand smoke can trigger an asthma attack in a child. Children with asthma who are around secondhand smoke have more severe and frequent asthma attacks. A severe asthma attack can put a child's life in danger.
• Children whose parents smoke around them get more ear infections. They also have fluid in their ears more often and have more operations to put in ear tubes for drainage.

Parents can help protect their children from secondhand smoke by taking the following actions:⁹

• Do not allow anyone to smoke near your child.
• Do not smoke or allow others to smoke in your home or car. Opening a window does not protect your children from smoke.
• Use a smoke-free day care center.
• Do not take your child to restaurants or other indoor public places that allow smoking.
• Teach children to stay away from secondhand smoke.

References

1. 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, Coordinating Center for Health Promotion, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, 2006 [accessed 2011 Mar 11].
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 2011 Mar 11].
3. Institute of Medicine. Secondhand Smoke Exposure and Cardiovascular Effects: Making Sense of the Evidence (PDF–707.47 KB). Washington: National Academy of Sciences, Institute of Medicine, 2009 [accessed 2011 Mar 11].
4. Centers for Disease Control and Prevention. Smoking-Attributable Mortality, Years of Potential Life Lost, and Productivity Losses—United States, 2000–2004. Morbidity and Mortality Weekly Report 2008;57(45):1226–8 [accessed 2011 Mar 11].
5. American Cancer Society. Cancer Facts and Figures 2009 . (PDF–1.7 MB) Atlanta: American Cancer Society, 2009 [cited 2011 Mar 11].
6. American Academy of Pediatrics, Task Force on Sudden Infant Death Syndrome. The Changing Concept of Sudden Infant Death Syndrome: Diagnostic Coding Shifts; Controversies Regarding the Sleeping Environment; and New Variables to Consider in Reducing Risk. Pediatrics 2005;116(5):1245–55 [cited 2011 Mar 11].
7. U.S. Department of Health and Human Services. The Health Consequences of Smoking: 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, 2004 [accessed 2011 Mar 11].
8. National Institutes of Health. Safe Sleep for Your Baby: Ten Ways to Reduce the Risk of Sudden Infant Death Syndrome (SIDS) . Rockville (MD): National Institutes of Health, National Institute of Child Health and Human Development, 2003 [accessed 2011 Mar 11].
9. U.S. Department of Health and Human Services. The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General: Secondhand Smoke: What It Means To You. . (PDF–11.05 MB) 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 2011 Mar 11].

For Further Information

Centers for Disease Control and Prevention
National Center for Chronic Disease Prevention and Health Promotion
Office on Smoking and Health
E-mail: tobaccoinfo@cdc.gov
Phone: 1-800-CDC-INFO

Media Inquiries: Contact CDC's Office on Smoking and Health press line at 770-488-5493.