# Research Status of Pathogenesis of Pneumoconiosis and Dust Control Technology in Mine--A Review
## 2 Research Progress of Mine Pneumoconiosis
### Pathological Study of Pneumoconiosis  
The typical pathological changes of pneumoconiosis are alveolitis and pulmonary interstitial fibrosis, as shown in Figure 3. The main pathological changes are as follows: (1) the early pathological changes of alveolitis include increased exudation of neutrophils, lymphocytes and macrophages in alveoli. Cell debris increased. Acute and chronic inflammatory cell infiltration and telangiectasia; more phagocytic dust granulocytes can be seen in the alveoli. With the increase of dust exposure time, coal spots were deposited in the lung stroma. (2) Black coal spots can be seen on the pleural surface and lung section. The coal spots are soft and black. After fusion, coal spots can increase and combine into pieces to form visible patches. According to the lung section, the coal spots were concentrated in the center of the lobules around the bronchioles and in the alveoli. Their deposition often compresses the bronchial smooth muscle, resulting in the expansion of the airway in the center of the lobules, which leads to the formation of lobular central emphysema. (3) \"Coal silicosis nodules\" and \"silicosis nodules\" can be seen. Coal silicosis nodules have the characteristics of \"coal lung\" and \"silicosis\". Under the microscope, there are two types: typical and atypical. The center of the former is a typical silicosis nodule, the collagen fibers are arranged radially like scallion skin, the surrounding coal dust deposits and fissures are separated, and the boundary is clear. The whole nodule is like a medal with ruby embedded in the middle, which is the characteristic lesion of \"coal silicosis\". In atypical cases, the lesions were larger than coal dust fibers, more than half of them were collagen fibers, and there were a small number of \"Silicon nodules\". (4) A large amount of coal dust is deposited around the alveolar septum, alveolar tract, interlobular septum, small blood vessels and bronchioles, resulting in fibrous hyperplasia and thickening, forming a diffuse fibrous network and causing pneumoconiosis interstitial fibrosis. (5) A large quantity of fibrosis is mainly concentrated in the upper segment of the lower lobe or the posterior segment of the upper lobe. At autopsy, the focus is a large black mass, often attached to the chest wall. The hardness of the mass is like rubber, and the boundary is usually unclear. When large, it can occupy most of the lung lobes, in the shape of a fissure, filled with ink like necrotic material. Figure 2: Dust inhalation experimental device for an animal model of coal workers’ pneumoconiosis [47]. 1. Feeding cage; 2. dust bin; 3. dust; 4. nozzle assembly; 4a. nozzle cover; 4b. nozzle base plate; 4c. return spring; 5. conical slider; 6a. connecting rod assembly; 6b and 6c. connecting rod shaft; 7. bearing; 8. movable table; 9. molar and drinking and eating device; 10. spring. Possible development direction in the later stage: Although previous studies have carried out a lot of research on the pathogenesis and pathogenesis of pneumoconiosis, and there are many hypotheses about the pathogenesis of coal workers' pneumoconiosis, the pathogenesis of coal workers' pneumoconiosis is not very clear. Compared with other pneumoconiosis, its research data are less, and most of them are limited to epidemiological investigation, body fluid composition detection pathological examination after autopsy or in vitro culture of bronchial epithelial cells. Therefore, it is difficult to dynamically and systematically observe the whole process of occurrence and development of pulmonary lesions of coal workers' pneumoconiosis. In particular, the pathogenic mechanism of pneumoconiosis induced by different metamorphic coal dust is not clear, which seriously limits the research and application of early diagnosis and treatment measures, and it is difficult to control the disease early.