Secondhand smoke has been classified by the U.S. Environmental Protection Agency (EPA) as a known cause of lung cancer in humans (Group A carcinogen). Passive smoking is estimated by EPA to cause approximately 3,000 lung cancer deaths in nonsmokers each year.

Secondhand smoke is a serious health risk to children.
 

• The developing lungs of young children are also affected by exposure to secondhand smoke.
• Infants and young children whose parents smoke are among the most seriously affected by exposure to secondhand smoke, being at increased risk of lower respiratory tract infections such as pneumonia and bronchitis. EPA estimates that passive smoking is responsible for between 150,000 and 300,000 lower respiratory tract infections in infants and children under 18 months of age annually, resulting in between 7,500 and 15,000 hospitalizations each year.
• Children exposed to secondhand smoke are also more likely to have reduced lung function and symptoms of respiratory irritation like cough, excess phlegm, and wheeze.
• Passive smoking can lead to buildup of fluid in the middle ear, the most common cause of hospitalization of children for an operation.