# Research Status of Pathogenesis of Pneumoconiosis and Dust Control Technology in Mine--A Review
## 2 Research Progress of Mine Pneumoconiosis
### Research Status of Pneumoconiosis Animal Models  
Establishing an appropriate model to reflect human chronic diseases is a challenge, especially for diseases with unknown etiology such as coal workers' pneumoconiosis. In the early stage, the pulmonary fibrosis model made of quartz has been widely used to study pulmonary fibrosis, but this model can not represent real pneumoconiosis. Because the pathogenesis and pathological changes of coal workers' pneumoconiosis are different from other diseases, it is necessary to establish and improve the animal model of coal workers' pneumoconiosis. Compared with other pneumoconiosis diseases, the dynamic development process of coal worker pneumoconiosis is less studied, and the pathogenesis is not clear, so it is difficult to control the early development of pneumoconiosis. At present, the research of pneumoconiosis is mostly limited to epidemiological investigation or detection of cells and body fluids in human bronchoalveolar lavage fluid. In recent years, the basic research of coal workers' pneumoconiosis is almost based on the animal model of rat coal workers' pneumoconiosis or rabbit coal workers' pneumoconiosis, using the one-time coal dust exposure method, that is, dropping coal dust suspension through the trachea. The typical pathological changes of coal workers' pneumoconiosis can be seen in lung pathology, but can the animal model of coal workers' pneumoconiosis made by one-time high-dose exposure accurately reflect the pathological changes of coal workers' dust exposure environment and chronic pneumoconiosis? This problem is worth exploring. Therefore, making an accurate animal dynamic model of coal worker pneumoconiosis is another important direction to study mine pneumoconiosis.  
There are few studies on making animal models by inhalation of dust in China and abroad. According to the experimental research method of animal chronic toxicology and the dust production characteristics of aerosols, [PERSON] [10] established a rat model of coal workers' pneumoconiosis that was established by non-exposed tracheal perfusion and aerosol inhalation. Then the lung function, cell composition of bronchoalveolar lavage fluid and lung histopathology were measured at different times after dust exposure. Through this study, the coal dust aerosol inhalation device established by the author can accurately and economically replicate the animal model of coal workers' pneumoconiosis in rats, and the animal mortality is low. It is in line with the pathogenic environment of coal workers' pneumoconiosis and the occurrence and development process of coal workers' pneumoconiosis, which is conducive to the clinical study of coal workers' pneumoconiosis.  
[PERSON] et al. [47] invented a dust inhalation experimental device for a coal workers' pneumoconiosis animal model, as shown in Figure 2. The device comprises a feeding cage, a dust nozzle, a drinking and eating device, etc. The shell of the conical nozzle is surrounded by a conical dust spraying cover and a bottom plate. A return spring and a dust falling convex cone are also installed in the shell. When the mouse approaches one end of the movable table and steps on the connecting rod assembly, the connecting rod assembly rotates around the rotating shaft, which drives the conical slider to move down, resulting in the dust in the dust bin falling along the outer wall of the conical slider, so as to achieve the effect of releasing dust. After the mouse loosens the connecting rod assembly,the return spring pushes the conical sliding block upward to closely fit with the conical dust spray cover to prevent dust from falling. The invention can simulate the process of periodic contact and active inhalation of dust by underground coal miners, better simulate the working environment of underground workers, and provide data support for exploring the pathogenic mechanism of dust in a coal mining environment.