Which factors are known to cause emphysema?

Emphysema is primarily caused by the destruction of the alveoli in the lungs, which impairs the respiratory system's ability to exchange gases effectively. Smoking is the most significant and well-established risk factor for emphysema. The harmful chemicals in tobacco smoke lead to inflammation and damage to lung tissue, contributing to the breakdown of alveoli. In addition, air pollution, which includes a range of harmful environmental pollutants, can also exacerbate lung damage and lead to the development and progression of emphysema.

Both smoking and air pollution are key environmental exposures that increase the oxidative stress and inflammation in the lungs, leading to the pathological changes associated with emphysema. Hence, recognizing smoking and air pollution as the main contributors to emphysema allows for targeted prevention strategies and helps in understanding the disease's etiology. The other factors, while they may contribute to general respiratory health, do not have the same level of direct association with the development of emphysema as smoking and air pollution.