Lung deposition is neither a disease nor a clinical manifestation, it is just a common similar medical term for certain substances or dust or impurities that can be deposited in the alveoli of the lungs through the respiratory tract. For example, in mines, especially in very dusty working environments such as digging and mining, there will be a lot of dust in the air that can pass through the respiratory tract, trachea and bronchial tubes, and finally be deposited in the lungs, resulting in the appearance of pneumoconiosis. Many occupational diseases are caused by the deposition of dust. Pneumoconiosis, silicosis and also asbestos mesh lungs are all categorized under the broad category of pneumoconiosis. Lung deposition may be more pronounced in the broad category of pneumoconiosis. If you smoke for a long time, or if you cook for a long time like burning briquettes or charcoal in the countryside, there will be smoke, and the impurities inside the smoke will be deposited in the lungs through the respiratory tract, and through bronchoscopy, it will be found that the patient’s mucous membranes of the trachea will be pigmented, and the walls of the tubes will become black, i.e., like charcoal will be darkened in the manifestation of the deposition of dust.