Secondhand smoke is classified as a
"known human carcinogen" (cancer-causing agent) by the US Environmental Protection Agency (EPA), the US National Toxicology Program, and the International Agency for Research on Cancer (IARC), a branch of the World Health Organization.
Secondhand smoke can be harmful in many ways. In the United States alone, each year it is responsible for:
- an estimated 35,000 deaths from heart disease in non-smokers who live with smokers
- about 3,400 lung cancer deaths in non-smoking adults
- other breathing problems in non-smokers, including coughing, mucus, chest discomfort, and reduced lung function
- 150,000 to 300,000 lung infections (such as pneumonia and bronchitis) in children younger than 18 months of age, which result in 7,500 to 15,000 hospitalizations
- increases in the number and severity of asthma attacks in about 200,000 to 1 million children who have asthma
- more than 750,000 middle ear infections in children
The
2006 US Surgeon General's report reached several important conclusions:
- Secondhand smoke causes premature death and disease in children and in adults who do not smoke.
- Children exposed to secondhand smoke are at an increased risk of sudden infant death syndrome (SIDS), acute respiratory infections, ear problems, and more severe asthma. Smoking by parents causes breathing (respiratory) symptoms and slows lung growth in their children.
- Secondhand smoke immediately affects the heart and blood circulation in a harmful way. It also causes heart disease and lung cancer.
- The scientific evidence shows that there is no "safe" level of exposure to secondhand smoke.
- Many millions of Americans, both children and adults, are still exposed to secondhand smoke in their homes and workplaces despite a great deal of progress in tobacco control.
- The only way to fully protect non-smokers from exposure to secondhand smoke indoors is to prevent all smoking in that indoor space or building. Separating smokers from non-smokers, cleaning the air, and ventilating buildings cannot keep non-smokers from being exposed to secondhand smoke.