How does smoking contribute to lung health risks?

Smoking significantly inhibits gas exchange within the lungs, which is vital for maintaining proper respiratory function. When cigarettes are smoked, harmful chemicals, including tar and nicotine, are introduced into the respiratory system. These substances damage the air sacs (alveoli) in the lungs, which are responsible for exchanging oxygen and carbon dioxide.

As the alveoli become damaged or inflamed due to prolonged exposure to smoke, their ability to facilitate the transfer of oxygen into the blood and carbon dioxide out of the blood is compromised. This impairment can lead to decreased oxygen levels in the body, necessitating compensatory mechanisms that can further strain cardiovascular health and overall organ function.

The other choices suggest positive effects on lung health, which are not accurate in the context of smoking. For instance, smoking does not promote lung regeneration; instead, it often leads to chronic obstructive pulmonary disease (COPD) and lung cancer. Similarly, it does not help in clearing airways—rather, it leads to increased mucus production and impeded airflow. Lastly, smoking does not improve lung capacity but rather decreases it over time, as lung tissues become less elastic and more fibrotic due to the damage caused by toxic substances in tobacco smoke.