Secondhand Smoke Dangers

There is No Safe Level of Exposure to Secondhand Smoke

While Colorado’s Clean Indoor Air Act has increased the protection of Coloradans by prohibiting smoking in restaurants and bars, too many people are still exposed to secondhand smoke (SHS) and the aerosol from electronic smoking devices (ESDs) – at work, during recreation and in outdoor seating areas such as restaurant patios. Below are facts about the impacts of SHS and how smoke-free laws protect citizens from the dangers of SHS. In addition to the harmful effects of SHS, new research has found that, long after a smoker leaves the premises, toxic chemicals from SHS remain and turn into something even more deadly: thirdhand smoke.


Secondhand Smoke is Harmful

SHS Effects On Non-Smokers:

In adults who have never smoked, SHS exposure…

  • Can cause many diseases, including heart disease and cancer.
  • Has immediate harmful effects on the cardiovascular system that can increase the risk for heart attack. People who already have heart disease are at especially high risk.1,2
  • Causes an estimated 46,000 heart disease deaths annually among nonsmokers in the US.3
  • Causes an estimated 3,400 lung cancer deaths annually among nonsmokers in the US.3


In children, SHS exposure…

  • Causes ear infections, more frequent and severe asthma attacks, respiratory symptoms (e.g. coughing, sneezing, shortness of breath), respiratory infections and a greater risk for sudden infant death syndrome (SIDS).1
  • Is responsible for an estimated 150,000–300,000 new cases of bronchitis and pneumonia each year and 7,500–15,000 hospitalizations annually in the US in children aged 18 months or younger.4
SHS Outdoors:

What about smoking outside? Doesn’t that reduce the SHS?

  • Depending on the amount of exposure, outdoor exposure to SHS can be greater than that caused by being in a smoky indoor area.
  • Sitting in an outdoor area for an hour with someone who smokes 2 cigarettes over the hour could result in exposure to a level of smoke particulate greater than that caused by being in a smoky indoor area for an hour.5
  • Drifting tobacco smoke, even outdoors, can trigger asthmatic attacks, bronchial infections, and other serious health problems in nonsmokers.
  • Even for people without respiratory conditions, breathing tobacco smoke can be deadly.6

SHS Laws:

Do strong smoke-free laws really help?

  • Studies show that laws prohibiting smoking in public places improve air quality, decrease air pollution, and improve the health of workers.
  • Studies also show that these laws do not have a negative economic impact on bars and restaurants.1,2
  • Download the fact sheet below on comprehensive smoke-free laws.

Third-hand Smoke

Did you know that the harmful effects of secondhand smoke linger long after the smoke has dissipated? This is called “third-hand smoke” (THS).

  • Researchers at University of California, Riverside found that THS toxicants in the environment had effects on various physiological processes including healing of wounds, function of the liver and lung, and the effects on behavior. Learn more about the study here.
  • A study in the journal Tobacco Control  found evidence indicating that third-hand smoke may play a role in the overall exposure of young children to tobacco smoke toxicants.

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.
2. Institute of Medicine. Secondhand Smoke Exposure and Cardiovascular Effects: Making Sense of the Evidence. Washington: National Academy of Sciences, Institute of Medicine, 2009.
3. 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):1226–1228.
4. US Environmental Protection Agency. Respiratory Health Effects of Passive Smoking: Lung Cancer and Other Disorders . Washington: US Environmental Protection Agency, Office of Research and Development, Office of Health and Environmental Assessment, 1992.
5. Klepeis N.E., Ott W.R., and Switzer P. (2007) “Real-Time Measurement of Outdoor Tobacco Smoke Particles,” Journal of the Air and Waste Management Association, 57:522-534.
6. “[S]moking bans are justified for health reasons in those outdoor environments which are similar to indoor environments in terms of their exposure to environmental tobacco smoke (ETS).” Bloch & Shopman, Outdoor smoking bans: more than meets the eye, Tobacco Control, 9:99, March 2000.