1. What are the common occupational lung diseases Occupational lung includes pneumoconiosis and other respiratory diseases, such as allergic pneumonia, cotton dust disease, asthma, metal and its compound dust lung deposition disease (tin, iron, antimony, barium and its compounds, etc.), chronic obstructive pulmonary disease due to irritating chemicals, and hard metal lung disease. Occupational pneumoconiosis is the most serious and widely affected occupational disease in China, accounting for 80% of the total number of reported occupational diseases in the country. Secondly, the incidence of metal and its compound dust pneumoconiosis is also quite high, and was included in the Classification and Catalogue of Occupational Diseases as a new occupational disease in 2013. 2. Clinical manifestations of silicosis Pneumoconiosis is a chronic disease, the course and clinical manifestations of which are related to the nature of dust exposure, concentration, exposure dose and the presence or absence of comorbidities. In general, short-term exposure to large amounts of dust with high concentrations or high free silica content results in rapid progression of lung tissue fibrosis and susceptibility to complications, and patients may experience deterioration in a relatively short period of time. Pneumoconiosis is generally asymptomatic or mild in the early stages, but in the middle and late stages it mainly manifests as cough, sputum, chest tightness, chest pain, dyspnea, and may be accompanied by hemoptysis and systemic symptoms. In combination with chronic bronchitis and other lung infections, the cough is significantly aggravated, accompanied by yellow sticky sputum, and the sputum of patients who have not yet left or just left dust work has the color of dust exposure, such as coal workers’ pneumoconiosis patients with black sputum, and asbestos lung patients with asbestos vesicles that can be examined in the sputum. Chest pain in pneumoconiosis patients is mostly vague or tingling, not severe, and may be caused by lesions such as thickening of the pleura or by the pulling effect of fibrotic lesions in the lungs. Hemoptysis in pneumoconiosis alone is rare and may be caused by the shedding of large fibrotic lesions, most hemoptysis is seen in pneumoconiosis combined with pulmonary tuberculosis. Common systemic symptoms are reduced digestive function, poor appetite, abdominal distention, constipation, etc. In early stage of pneumoconiosis, there are usually no positive signs on physical examination. In middle and late stage of pneumoconiosis, dry and wet rales may appear, especially when combined with pulmonary infection; wheezing sounds may be heard when combined with wheezing bronchitis; barrel-shaped chest, widening of rib space, weakened palpable fibrillation, pestle fingers, etc. when combined with emphysema and chronic pulmonary heart disease.