Carbon black is the main group of industrial carbon, which is generally made of petroleum, asphalt, natural gas and coke through incomplete combustion and thermal degradation. Industrial carbon black is easy to fly because of its small particle size. Generally, the content of free silica is very small, below 1.5%. Carbon black is widely used in rubber, plastics, paints, inks, dyes, records and dry batteries.
Workers who produce and use carbon black may suffer from carbon black pneumoconiosis if they inhale carbon black dust for a long time. Length of service is above 15a: the clinical symptoms are mild, the progress is slow, most of them have no positive signs, and the working ability is generally unaffected or slightly affected. On the chest film, the hilum of the lung is slightly enlarged, the density is increased, and the lung texture is enhanced. On the basis of reticular shadows, small quasi-circular shadows and irregular shadows can be seen. The lesion is similar to coal lung, and most dark black dust spots can be seen on the pleural surface and section. Microscopically, dust spots are amorphous or star-shaped, consisting of a large number of dust and dust cells, or a small amount of fiber hyperplasia. Dust spots are mostly located around bronchioles and respiratory bronchioles and small blood vessels. Most of them are accompanied by perifocal or lobular emphysema. The former is confined to the vicinity of dust spots, while the latter is peripheral airway dilatation centered on respiratory bronchioles. With the progress of the disease, it extends to alveolar ducts, alveolar ducts and alveoli, forming lobular emphysema. If a certain amount of silicon dioxide is mixed into carbon black (such as raw material crushing and old-fashioned recording treatment), the lungs of workers may form nodules and a lot of fibrosis, which is very similar to coal silicosis. Diagnosis, treatment and prevention are similar to pneumoconiosis.