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Medical Author:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Medical Editor:

Charles Patrick Davis, MD, PhD

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

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In this Article

• What is secondhand smoke?
• What causes secondhand smoke?
• What are the health risks of secondhand smoke?
• Lung cancer and secondhand smoke
• Cardiovascular disease and secondhand smoke
• Other lung diseases and secondhand smoke
• Secondhand smoke and other effects on children
• Secondhand smoke and the effects on pregnant women
• Secondhand smoke and the possible link to breast cancer
• Is there a safe level of secondhand smoke?
• What is thirdhand smoke?
• What can be done about secondhand smoke exposure?
• Secondhand Smoke At A Glance
• Find a local Family Physician in your town
• Secondhand Smoke Index

Passive smoking is an established risk factor for the development of lung cancer. Research has shown that nonsmokers who reside with a smoker have a 20% to 30% increase in risk for developing lung cancer when compared with nonsmokers who do not reside with a smoker. An estimated 3,400 lung cancer deaths that occur each year in the U.S. are attributable to passive smoking.

Like cigarette smoking itself, secondhand smoke is a significant risk factor for the development of cardiovascular disease and heart attack. An estimated 46,000 deaths from heart disease in non-smokers who live with smokers occur every year in the U.S.

Coughing, chest congestion, and decreased lung function can also occur in those exposed to passive smoke. Babies exposed to secondhand smoke can also develop serious respiratory infections. In the U.S., passive smoking is believed to cause 150,000 to 300,000 lung infections (such as pneumonia and bronchitis) in children younger than 18 months of age each year.

In addition to the risk of pneumonia and respiratory infections in babies exposed to secondhand smoke (see above), passive smoke is known to increase the severity of asthma in children with this condition. About 750,000 middle ear infections in children are also estimated to occur each year as a result of exposure to secondhand smoke. Babies who are exposed to secondhand smoke are at an increased risk for sudden infant death syndrome (SIDS).