Cigarette smoke is toxic soup of more than 7,000 known chemical compounds. Secondhand smoke is composed of sidestream smoke (the smoke released from the burning end of a cigarette) and exhaled mainstream smoke (the smoke exhaled by the smoker). Tobacco smoke contains thousands of different chemicals that are released into the air as particles and gases. The particulate phase of cigarette smoke includes nicotine, “tar” (itself composed of many chemicals), benzene and benzo(a)pyrene. The gas phase includes carbon monoxide, ammonia, dimethylnitrosamine, formaldehyde, hydrogen cyanide and acrolein. According to the National Cancer Institute, there are 69 known or probable carcinogens in cigarette smoke.

The scientific evidence on the health risks associated with exposure to secondhand smoke is clear, convincing, and overwhelming.

Secondhand smoke (also referred to as involuntary smoking, environmental tobacco smoke, and passive smoking) is a known cause of lung cancer, heart disease, low birth-weight births, chronic lung ailments, as well as other health problems. According to the Centers for Disease Control and Prevention (CDC), nearly 50,000 Americans die each year from lung cancer and heart disease attributable to secondhand smoke exposure.

Health risks associated with exposure to secondhand smoke

U.S. Surgeon General (2010) – In the report, How Tobacco Smoke Causes Disease: The Biology and Behavioral Basis for Smoking Attributable Disease, The Surgeon General concluded that:
— Tobacco smoke contains more than 7,000 chemicals and compounds, including hundreds that are toxic and at least 69 that cause cancer.
— Every exposure to the cancer-causing chemicals in tobacco smoke can damage DNA in a way that leads to cancer.
— Exposure to secondhand smoke has an immediate adverse impact on the cardiovascular system, damaging blood vessels, making blood more likely to clot and increasing risks for heart attack and stroke.

U.S. Surgeon General (2006) – In the report, The Health Consequences of Involuntary Exposure to Tobacco Smoke, the Surgeon General concluded that:
— Secondhand smoke exposure causes disease and premature death in children and adults who do not smoke.
— Children exposed to secondhand smoke are at an increased risk for sudden infant death syndrome (SIDS), acute respiratory infections, ear problems, and more severe asthma. Smoking by parents causes respiratory symptoms and slows lung growth in their children.
— Exposure of adults to secondhand smoke has immediate adverse effects on the cardiovascular system and causes coronary heart disease and lung cancer.
— The scientific evidence indicates that there is no risk-free level of exposure to secondhand smoke.

Institute of Medicine (2009) – In a landmark report, Secondhand Smoke Exposure and Cardiovascular Effects:
Making Sense of the Evidence, the Institute of Medicine (IOM) concludes smoke-free laws reduce the number of heart attacks and save lives. The report also confirms that there is conclusive scientific evidence that secondhand smoke causes heart disease, including heart attacks. The IOM report was requested by the Centers for Disease Control and Prevention (CDC) in the wake of a growing number of studies in smoke-free localities, states and countries that found reductions in heart attack rates after smoke-free laws are implemented. After a thorough review of the evidence, an IOM committee of scientific experts reached the following conclusions: The committee concludes that there is a causal relationship between smoking bans and decreases in acute coronary events. The evidence reviewed by the committee is consistent with a causal relationship between secondhand-smoke exposure and acute coronary events, such as acute MI (myocardial infarction). The committee concludes that it is biologically plausible for a relatively brief exposure to secondhand smoke to precipitate an acute coronary event.” According to the report, experimental studies have found that secondhand smoke exposure causes adverse changes in the cardiovascular system that increase the risk of a heart attack. The Centers For Disease Control and Prevention also stated that studies conducted in several communities, states, and countries have found that implementing smoke-free laws is associated with reductions in hospital heart attack admissions. The CDC notes that, “smoke-free laws likely reduce heart attack hospitalizations both by reducing secondhand smoke exposure among nonsmokers and by reducing smoking, with the first factor making the larger contribution.” Based on earlier evidence, experts at the U.S. Centers for Disease Control and Prevention had previously noted to all clinicians with patients who have a history of coronary heart disease that those patients “should be advised to avoid all indoor environments that permit smoking.” – World Health Organization (2007) – In its report, Protection From Exposure To Secondhand Tobacco Smoke – Policy Recommendations, the World Health Organization stated that: “Scientific evidence has firmly established that there is no safe level of exposure to second-hand tobacco smoke (SHS), a pollutant that causes serious illness in adults and children. There is also indisputable evidence that implementing 100% smoke-free environments is the only effective way to protect the population from the harmful effects of exposure to SHS.”

Workers Health and Exposure to Secondhand Smoke

Exposure to secondhand smoke is associated with disease and premature death in nonsmoking adults and children.2.  It is the third leading cause of preventable death in this country, killing 53,000 non-smokers in the US each year.17. Nonsmokers regularly exposed to SHS suffer death or morbidity rates as much as 30% higher than those of unexposed nonsmokers.18.

Secondhand smoke is proven to cause lung cancer in non-smokers19 causing an estimated 3,400 lung cancer deaths in the United States each year.3. There is also evidence linking SHS to other types of cancers, including childhood leukemia and breast cancer.13

Even brief exposure to secondhand smoke has immediate effects on the respiratory and circulatory systems.2. These effects interfere with the normal functioning of the heart, blood, and vascular systems in ways that increase the risk of heart attacks.16.

Secondhand smoke exposure is especially hazardous to elderly people with existing chronic health conditions. Children who breathe secondhand smoke are at an increased risk for sudden infant death syndrome (SIDS), ear and respiratory infections, and asthma.2. Chronic exposure to SHS by pregnant women can have adverse effects on the developing fetus. 2.

The workplace is a major source of secondhand smoke exposure. 2 Employees who work in smoke-filled businesses suffer a 25-50% higher risk of heart attack and higher rates of death from cardiovascular disease and cancer as well as increased acute respiratory disease and measurable decrease in lung function.23 Some studies have found they have as much as a 50% increase in lung cancer risk due to tobacco smoke exposure in the workplace.22

1.  World Health Organization. WHO Report on the Global Tobacco Epidemic, 2009. Geneva: World Health Organization, 2008.

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: U.S. Dept. 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.

3.  American Cancer Society. Cancer Facts & Figures 2013. Atlanta: American Cancer Society, 2013.

4.  American Cancer Society. Cigarette Smoking.www.cancer.org/acs/groups/cid/documents/ webcontent/002967-pdf.pdf. Last updated: January 17, 2013.

5.  U.S. Department of Health and Human Services. Ending the Tobacco Epidemic: Progress Toward a Healthier Nation. Washington: U.S. Department of Health and Human Services, Office of the Assistant Secretary for Health, 2012.

6.  Campaign for Tobacco-Free Kids. Toll of Tobacco in the United States of America. http://www.tobaccofreekids.org/ research/factsheets/pdf/0072.pdf   Last updated: February 6, 2013.

7.  Centers for Disease Control and Prevention. Tobacco Control State Highlights 2012. 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, 2013.

8.  The West Virginia Division of Tobacco Prevention. Tobacco is Killing (and Costing) Us: A Report on Tobacco Use Rates, Smoking-Related Deaths, and Smoking-Related Health Care Costs in West Virginia. Charleston, WV: WV Bureau for Public Health, 2009.

9.  West Virginia Department of Health and Human Services.  2007 and 2009 West Virginia Youth Tobacco Survey Report. Charleston, WV: West Virginia Bureau for Public Health Statistics Center, 2011. 

10.Campaign for Tobacco-Free Kids. The Toll of Tobacco in West Virginia.www.tobaccofreekids.org/facts_issues/toll_us/west_virginia.   Last updated: December 5, 2012.

11.The West Virginia Division of Tobacco Prevention. Tobacco Is Killing (and Costing) Us, 2005-2009. (The 2012 Updated Summary of the Tobacco is Killing and Costing Us Report.) Charleston, WV:  WV Bureau for Public Health, 2012.

12.Fielding, J. E., and Phenow, K. J. (1988). “Health Effects of Involuntary Smoking.”  New England Journal of Medicine, 319, 1452–1460

13.American Cancer Society. What is Secondhand Smoke?www.cancer.org/cancer/ cancercauses/tobaccocancer/secondhand-smoke.  Last updated: January 17, 2013. 

14.Repace, J.L. ”Exposure to Secondhand Smoke”, Chapter 9 in: Exposure Analysis. W. Ott, A. Steinemann, and L. Wallace, Eds. CRC Press, 2006.

15.Americans for Nonsmoker’s Rights.  Thirdhand Smoke.  http://www.no-smoke.org/ learnmore.php?id=671 Last updated: April 2, 2013.

16.U.S. Department of Health and Human Services. How Tobacco Smoke Causes Disease: The Biology and Behavioral Basis for Smoking-Attributable Disease: A Report of the Surgeon General. Atlanta, GA: 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.

17.Glantz, S.A. & Parmley, W. Passive Smoking and Heart Disease: Epidemiology, Physiology, and Biochemistry, Circulation, 1991; 83(1):1-12; and, Taylor, A., Johnson, D. & Kazemi, H., Environmental Tobacco Smoke and Cardiovascular Disease, Circulation, 1992; (86): 699-702.

18.Americans for Nonsmoker’s Rights. Secondhand Smoke: The Science.  www.no-smoke.org/ pdf/SHS.pdf. November 2006.

19.U.S. Environmental Protection Agency. Respiratory Health Effects of Passive Smoking (Also Known as Exposure to Secondhand Smoke or Environmental Tobacco Smoke—ETS). U.S. Environmental Protection Agency, 1992.

20.U.S. Department of Health and Human Services. Preventing Tobacco Use Among Youth and Young Adults: A Report of the Surgeon General. Atlanta, GA: 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, 2012.

21.Fracasso, M.E. et al. “DNA Damage and Repair Capacity by Comet Assay in Lymphocytes of White-collar Active Smokers and Passive Smokers (non- and ex-smokers) at Workplace,” Toxicology Letters 167(2): 131–141, December 1, 2006.

22.Siegel, Michael (1993). “Involuntary Smoking in the Restaurant Workplace: A Review of Employee Exposure and Health Effects,” JAMA 270(4): 490-493.

23.Pitsavos, C. et al. “Association Between Exposure to Environmental Tobacco Smoke and the Development of Acute Coronary Syndromes: the CARDIO2000 Case-control Study”, Tobacco Control 11(3): 220-225, September 2002.)

24.Building Trades Unions Ignite Less Tobacco [BUILT] Project. Unions Yes – Tobacco No. California: Department of Health Services, 2001.

25.West Virginia Division of Tobacco Prevention. Secondhand Smoke Fact Sheet. www.wvdtp.org/ Portals/5/SHS%20FACTsheet%20%20011510.pdf.  January 2010.

Secondhand Smoke and Your Pet

Pets in homes of those who smoke are affected by their owner’s second & thirdhand smoke. Visit the VCA site for more information. Dogs, cats, and especially birds at greater risk of health problems. Dogs exposed to second-hand smoke have more eye infections, allergies, and respiratory issues including lung cancer. … Long nosed dogs are prone to nasal cancer while short nosed dogs often get lung cancer.

Visit the VCA or the FDA website also for information on the effects secondhand and thirdhand smoke on your pets.

Thirdhand smoke

Thirdhand smoke (THS) refers to the chemical residue left behind after smoking has stopped. THS clings to carpets, walls, toys, and other furnishings in a room. THS is also found on clothing worn by a smoker during smoking or nonsmokers when exposed to secondhand smoke and in other areas where smoking occurs such as vehicles. Thirdhand smoke can persist in an area for months or even years. THS contains some of the same chemicals as cigarette smoke and has many negative consequences on health. Research has shown: DNA damage Lung inflammation High blood sugar levels Hyperactive behavior Damaged cells in the respiratory system after just a few hours or exposure For more information on Thirdhand Smoke, visit the Thirdhand Smoke Resource Center.