I. What is asbestos? Asbestos is the general name of natural fibrous silicate minerals. Asbestos is divided into two categories: serpentine, whose fibers are long and soft, the main variety is chrysotile; hornblende, whose fibers are short and thin and hard, the main varieties are crocidolite, amosite and anthophyllite. Asbestos is an important fireproof, insulating and thermal insulation material because of its high fire resistance, electrical insulation and adiabatic properties, and is very widely used in industrial production and daily life. II. What are the uses of asbestos? Chrysotile asbestos accounts for 95% of the world’s total asbestos consumption, while crocidolite and amosite account for less than 5% of the total asbestos consumption and are mainly used in shipbuilding. The uses of asbestos are widely listed as follows. (1) Textile industry: The fibers of chrysotile have excellent spinning properties and are processed by textile machinery to make asbestos products. Asbestos yarn can be processed by rope-making machinery to make various ropes, and can also be woven into asbestos cloth to sew asbestos clothing, asbestos boots, asbestos gloves and other labor protection products. (2) Construction industry: Asbestos can be made into asbestos sheets, asbestos fireproof paper, heat insulation pipes, and other materials for heat insulation, heat prevention, insulation and sound insulation. Asbestos fiber can also be mixed with cement to make asbestos cement tiles, boards, roofing sheets, asbestos pipes and other asbestos cement products. Asbestos and asphalt can be mixed to make asbestos asphalt products, such as asbestos asphalt sheets, cloth (linoleum), paper and bricks, as well as liquid asbestos paint, putty for embedded cement pavement and expansion cracks, etc., which are used as waterproof, heat insulation, insulation, acid and alkali resistant materials for buildings and traffic engineering. (3) Industry: Asbestos can be made into heat insulation products, asbestos rubber products, asbestos electrical materials, asbestos brake and transmission products, etc. Because asbestos has high mechanical strength, it can be used as asbestos products. Because asbestos has high mechanical strength and heat resistance, and good friction performance, asbestos is indispensable for any transmission machinery and transportation. C. What is the danger of asbestos to human health? Asbestos itself is not toxic, but the main hazard of asbestos is that asbestos dust, when inhaled into the human body, will adhere to and deposit in the lungs, causing lung fibrosis and pleural damage. Also, asbestos is recognized as a Group I carcinogen by the International Agency for Research on Cancer (IARC). Asbestos causes malignant tumors, mainly lung cancer and mesothelioma, and has also been reported to cause digestive system tumors, head and neck tumors, and reproductive system tumors after asbestos exposure. Due to the widespread use of asbestos, occupational and environmental exposure to asbestos poses a potential threat to the health of the population. IV. Examples of health threats from asbestos exposure. In the 1950s and 1960s, China was not aware of the health hazards caused by asbestos. In order to facilitate their work and to take care of their children, the asbestos weaving workshops were equipped with baby rooms, and many women put their children in the baby rooms. Older children helped their mothers to spin asbestos together or played around. Community residents also received incoming material from asbestos factories and spun asbestos in neighborhoods or homes. The occupational exposure, along with the environmental contamination, led to the development of asbestosis and even asbestos-related malignancies in multiple family members over the years. V. What are the clinical manifestations of asbestosis? Asbestosis usually develops 10-40 years after the onset of asbestos dust exposure, with a long latent period. The natural course of the disease is chronic and progressive, and patients gradually develop exertional dyspnea, which may be accompanied by a dry cough. Chest imaging is characterized by interstitial pneumonia of a nonspecific interstitial pneumonia type or a generalized interstitial pneumonia type, with irregular thickening of the pleura, and calcification. Early asbestosis pulmonary function is in the normal range, with gradual development of restrictive ventilation dysfunction with reduced diffusion volume. Asbestosis needs to be differentiated from interstitial pneumonia of other etiologies, as well as from idiopathic pulmonary fibrosis, idiopathic nonspecific pneumonia, and chronic allergic pneumonia. Pleural plaques are defined as limited pleural thickening. The substances known to cause pleural plaques are asbestos, grossular zeolite, calcium silica, and refractory ceramic fibers. In most cases, pleural plaques are due to asbestos and are indicative of asbestos exposure, which is an important hint for differential diagnosis. Pleural plaques due to asbestos also need to be differentiated from tuberculous pleural hypertrophy in China, a region with a high prevalence of tuberculosis infection and disease. Asbestos pleural plaques involve the mural pleura, whereas tuberculous pleural hypertrophy involves the mural and visceral pleura, and the lesions are mostly unilateral, mostly involving the angle of the rib diaphragm. Since the onset of asbestosis is often long before asbestos exposure, patients may forget or not realize the problem of asbestos exposure at work or in the environment, and physicians need to take a detailed and comprehensive medical history. Sixth, the diagnosis of the disease should pay attention to the possible lung damage caused by occupational and environmental exposure factors. During the diagnosis of interstitial lung disease, clinicians should pay attention to the questioning of occupational and environmental exposure factors during the initial consultation, and conduct in-depth and excavatory questioning based on the condition and imaging features. Clinicians need to have knowledge related to the health hazards of occupational and environmental exposures, and pay attention to diseases caused by occupational exposure to dust, chemicals, and physical factors. Patients should actively cooperate with their physicians in the search for possible causes of interstitial lung disease.