Final answer:
Smoking is the most important risk factor in pulmonary disease. Exposure to tobacco smoke by smoking or by breathing air that contains tobacco smoke is the leading cause of preventable death in the United States. Avoiding smoking and secondhand smoke are the best ways to reduce the risk of developing chronic respiratory diseases.
Step-by-step explanation:
Smoking is the most important risk factor in pulmonary disease. Exposure to tobacco smoke by smoking or by breathing air that contains tobacco smoke is the leading cause of preventable death in the United States. Regular smokers die about 10 years earlier than nonsmokers. Avoiding smoking and secondhand smoke are the best ways to reduce the risk of developing chronic respiratory diseases, such as lung cancer. Other factors like air pollution and genetics can also play a role in pulmonary diseases, but smoking is the major cause.