Quit Smoking Glossary

Secondhand Smoke — Health Risks for Non-Smokers and Your Family

Secondhand smoke is the combination of smoke exhaled by a smoker and smoke emitted from the burning tip of a cigarette, inhaled involuntarily by people nearby.

What is Secondhand Smoke?

Secondhand smoke (also called passive smoke or environmental tobacco smoke) is a mixture of the smoke exhaled by the smoker and the smoke that burns off the end of a cigarette. It contains more than 7,000 chemicals, hundreds of which are toxic and about 70 of which can cause cancer. There is no safe level of exposure. Children are particularly vulnerable because their lungs and immune systems are still developing. Regular exposure increases the risk of sudden infant death syndrome (SIDS), asthma, respiratory infections, and ear infections in children. In adults, secondhand smoke exposure raises the risk of heart disease by 25–30% and lung cancer by 20–30% compared to non-exposed non-smokers.

  • Contains over 7,000 chemicals, 70 of which are known carcinogens
  • Raises heart disease risk by 25–30% in exposed adults
  • Raises lung cancer risk by 20–30% in non-smokers with regular exposure
  • Increases SIDS risk for infants by up to 50%
  • Worsens asthma and causes respiratory infections in children

SmokeClock How SmokeClock helps with Secondhand Smoke

By reducing and eventually eliminating smoking, SmokeClock directly reduces secondhand smoke exposure for everyone around you. During the reduction phase, scheduling cigarettes for specific times and locations makes it easier to avoid smoking indoors or near children — protecting your household while you work toward quitting.

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