Cardiovascular diseases caused by smoking include heart disease and stroke. Diseases of the
respiratory system that are caused by exposure to tobacco smoke include emphysema, lung
cancer, and cancers of the larynx and mouth. Cigarette smoking causes 87 percent of lung
cancer deaths. Smoking and using tobacco is also linked to the risk of developing other types
of cancer such as pancreatic and stomach cancer.
Cigarettes, like the ones shown inFigure19.11, are a major source of indoor air pollution.
Cigarettesmokecontainsabout4,000substances, includingover60cancer-causingchemicals.
Many of these substances, such as carbon monoxide, tar, arsenic, and lead, are toxic to the
body. Non-smokers can also be affected by tobacco smoke. Exposure to secondhand smoke,
also known asenvironmental tobacco smoke (ETS), greatly increases the risk of lung
cancer and heart disease in nonsmokers.
Chronic obstructive pulmonary disease (COPD)is a disease of the lungs in which
the airways become narrowed. This leads to a limitation of the flow of air to and from the
lungs causing shortness of breath. The limitation of airflow usually gets worse over time.
COPD is most commonly caused by smoking. Gases and particles in tobacco smoke trigger
an abnormal inflammatory response in the lung. The inflammatory response in the larger
airways is known as chronic bronchitis. In the alveoli, the inflammatory response causes the
breakdown of the tissues in the lungs, leading to emphysema.
Figure 19.11: Tobacco use, particularly cigarette smoking, is the single most preventable
cause of death in the United States. ( 7 )