Coal dust or cholesterol crystallized mucous sputum is a symptom of the clinical manifestations of coal workers’ pneumoconiosis. Coal workers’ pneumoconiosis (coalminer’s pneumoconiosis) is the general term for lung lesions caused by coal miners inhaling dust from the production environment over a long period of time. It includes coal pneumoconiosis caused by inhalation of pure coal dust by coal miners and coal miners, which accounts for about 10%; silicosis caused by inhalation of silica dust by rock diggers, which accounts for less than 10%; and coal pneumoconiosis caused by inhalation of coal dust and silica dust and other mixed dust, which mainly occurs in mixed types of coal miners who both dig and mine coal, accounting for about 80% or more. Coal silicosis is the most common in coal mines. Coal workers’ pneumoconiosis occurs mainly among underground miners, and the prevalence is very low among surface coal miners. Coal pneumoconiosis can also occur in other workers who are exposed to large amounts of coal dust, such as dock unloaders and briquette makers, but because it does not affect labor capacity much, there is not much research. Differential diagnosis of mucous sputum of coal dust or cholesterol crystals: White mucous sputum: mostly transparent sputum or slightly white, thinner, usually caused by cold or mild bronchitis, healthy humans also have a small amount of white sputum. Yellow purulent sputum: caused by purulent infection of the lungs, usually secondary to pneumonia, bronchitis, lung abscess or bronchiectasis, more inflammatory compared to white mucous sputum. Yellow-green sputum: caused by a special kind of bacteria – Pseudomonas aeruginosa infection, the appearance of this color of sputum should go to the hospital as soon as possible to do sputum culture to identify the cause. Rusty sputum: The sputum of lobar pneumonia is rusty in color, mostly accompanied by symptoms such as dyspnea and chest pain, and is mostly caused by S. pneumoniae, Staphylococcus and S. pneumoniae. Bloody sputum: Bloody sputum can be divided into several cases: one is bright red blood in sputum, mostly seen in tuberculosis or bronchial dilatation, and sometimes this can also occur when there is inflammation in the pharynx; the second is black bloody sputum, mostly seen in pulmonary infarction; the third, pink foam-like sputum, seen in pulmonary edema. In addition, if there is blood in the sputum for a long time or accompanied by symptoms of chest pain, weakness and wasting, be alert to the occurrence of lung cancer. Jam-like sputum: Suggests parasitic diseases of the lungs, such as pulmonary schistosomiasis; it can also occur in amebic lung abscesses. A blood test at the hospital will identify the cause. Gray or black sputum: Coughing up gray sputum from excessive inhalation of dust; long-term exposure to carbon dust, coal fumes, and lime can lead to pulmonary pneumoconiosis. Odorous sputum: When the lungs are infected with anaerobic bacteria, the sputum coughed up will smell bad. Brick-red mucous jelly-like sputum: Suggests Pneumocystis pneumonia, which is generally less common.