How does smoking affect lung function over time?

Smoking has a well-established, detrimental impact on lung function over time, primarily due to the processes of airway inflammation and damage that it induces. When a person smokes, the inhalation of harmful substances found in tobacco leads to chronic inflammation in the airways, which can result in structural changes. This inflammation narrows the air passages and disrupts normal lung function.

Additionally, the toxic chemicals in cigarette smoke can cause damage to the lung tissues and impair ciliary function, which is essential for clearing mucus and debris from the lungs. Over time, this results in reduced airflow and can lead to obstructive diseases, such as chronic bronchitis and emphysema, collectively known as Chronic Obstructive Pulmonary Disease (COPD). These diseases are characterized by a progressive decline in lung function, making it increasingly difficult for individuals to breathe.

Therefore, the option that states smoking leads to a decline in lung function due to airway inflammation and damage accurately reflects the harmful effects of smoking on respiratory health.