The cause of<unk>  is unknown but certain environmental factors and exposures have been shown to increase the risk of getting<unk> . Cigarette smoking is the best recognized and most accepted risk factor for<unk> , and increases the risk of<unk>  by about twofold. Other environmental and occupation exposures such as exposure to metal dust, wood dust, coal dust, silica, stone dust, biologic dusts coming from hay dust or mold spores or other agricultural products, and occupations related to farming/livestock have also been shown to increase the risk for<unk> . There is some evidence that viral infections may be associated with<unk>  and other fibrotic lung diseases.
Idiopathic pulmonary fibrosis
Sarcoidosis
Mineral dust airway disease
Hypersensitivity pneumonitis
Allergic bronchopulmonary aspergillosis
Interstitial lung disease
Rheumatoid lung disease
Idiopathic interstitial pneumonia