Health Problems Caused by Secondhand Smoke

Key points

  • There is no safe level of exposure to secondhand smoke.
  • People who do not smoke but who are exposed to secondhand smoke, even for a short time, can suffer harmful health effects.

Overview

  • There is no safe level of exposure to secondhand smoke (SHS); even brief exposure can cause immediate harm.123
  • Health problems caused by secondhand smoke in adults who do not smoke include coronary heart disease, stroke, and lung cancer, as well as adverse reproductive health effects in women, including low birth weight.13
  • Secondhand smoke can cause sudden infant death syndrome (SIDS), respiratory infections, ear infections, and asthma attacks in infants and children.1

What are the health problems caused by secondhand smoke?

The effects of secondhand smoke exposure on the body are immediate.13 Since 1964, about 2,500,000 people who did not smoke died from health problems caused by secondhand smoke exposure.1

  • In adults who do not smoke, secondhand smoke exposure can cause coronary heart disease, stroke, lung cancer, and other diseases. It can also result in premature death.123
  • Secondhand smoke can cause adverse reproductive health effects in women, including low birth weight.13
  • In children, secondhand smoke exposure can cause respiratory infections, ear infections, and asthma attacks. In babies, secondhand smoke can cause sudden infant death syndrome (SIDS).123
  • Secondhand smoke exposure can produce harmful inflammatory and respiratory effects within 60 minutes of exposure which can last for at least three hours after exposure.4
Diagram showing health effects in adult body and child body.
Health effects of secondhand smoke on adults and children.

Secondhand smoke causes heart disease and stroke

For adults who do not smoke, exposure to secondhand smoke has immediate harmful effects on the heart and blood vessels and can cause coronary heart disease and stroke.135

  • Among adults who do not smoke, secondhand smoke causes nearly 34,000 premature deaths from heart disease each year in the U.S.1
  • Adults who do not smoke and are exposed to secondhand smoke increase their risk of developing coronary heart disease by 25–30%.1
  • Adults who do not smoke and are exposed to secondhand smoke increase their risk of stroke by 20−30%.1
  • Exposure to 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.123
  • Even brief exposure to secondhand smoke can damage the lining of blood vessels and cause blood platelets to become stickier. These changes can cause an increased risk of heart attack.123
  • People who already have heart disease are at especially high risk of suffering the harmful effects from breathing secondhand smoke. They should take special precautions to avoid even brief exposures.1

Secondhand smoke causes lung cancer

  • Adults who do not smoke and are exposed to secondhand smoke increase their risk of developing lung cancer by 20–30%.13
  • Secondhand smoke causes more than 7,300 lung cancer deaths each year among U.S. adults who do not smoke.13
  • People who do not smoke but are exposed to secondhand smoke are inhaling many of the same cancer-causing substances and poisons that are inhaled by people who smoke.123
  • Even brief exposure to secondhand smoke can damage the body's cells in ways that set the cancer process in motion.1
  • 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.1

Secondhand smoke causes reproductive health problems in pregnant people

  • Women exposed to secondhand smoke during pregnancy are more likely to have newborns with lower birth weight, increasing the risk of health complications.12

Secondhand smoke causes sudden infant death syndrome (SIDS)

  • Infants exposed to secondhand smoke after birth are more likely to die from sudden infant death syndrome (SIDS) than infants who are not exposed to smoke from burning commercial tobacco products.1245 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
  • Smoking by women during pregnancy increases the risk for SIDS.137
  • Chemicals in secondhand smoke appear to affect the brain in ways that interfere with its regulation of infants' breathing.13
  • 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.13

Secondhand smoke can trigger asthma attacks and cause other health problems in children

  • Children who are exposed to secondhand smoke are at an increased risk for acute respiratory infections such as pneumonia and bronchitis, middle ear disease, more frequent and severe asthma, respiratory symptoms, and slowed lung growth.1
  • Wheezing, coughing, and shortness of breath are more common in children exposed to secondhand smoke.3
  • 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.3
  • 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.3
  1. U.S. Dept of Health and Human Services. The Health Consequences of Smoking—50 Years of Progress: A Report of the Surgeon General. U.S. Dept of Health and Human Services; 2014.
  2. U.S. Dept of Health and Human Services. A Report of the Surgeon General: How Tobacco Smoke Causes Disease...What It Means to You. U.S. Dept of Health and Human Services; 2010.
  3. U.S. Dept of Health and Human Services. The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General. U.S. Dept of Health and Human Services; 2006.
  4. Flouris AD, Koutedakis Y. Immediate and short-term consequences of secondhand smoke exposure on the respiratory system. Curr Opin Pulm Med. 2011;17(2):110–115.
  5. Institute of Medicine Committee on Secondhand Smoke Exposure and Acute Coronary Events. Secondhand Smoke Exposure and Cardiovascular Effects: Making Sense of the Evidence. National Academies Press; 2010.
  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):1245–1255.
  7. U.S. Dept of Health and Human Services. The Health Consequences of Smoking: A Report of the Surgeon General. U.S. Dept of Health and Human Services; 2004.