Environmental tobacco smoke (ETS), or secondhand smoke, is increasingly recognized as the direct cause of lung disease in adults and children.
ETS is responsible for significant mortality in adults, causing approximately 3000 deaths per year from lung cancer. It also causes significant effects on the lung health of adult nonsmokers, including reduced lung function, increased sputum production and cough, and chest discomfort.
In children, ETS is associated with an increased risk of lower respiratory tract infections (LRTIs), such as bronchitis and pneumonia. An estimated 150,000-300,000 cases of LRTIs in children younger than 18 months are attributed to ETS annually. ETS is causally associated with increased prevalence of fluid in the middle ear, upper respiratory tract irritation, and reduced lung function. It is also associated with increased severity of asthma in children;
the asthma of an estimated 200,000-1,000,000 children is worsened by ETS. Finally, ETS is a risk factor for the development of asthma in children.