Lung cancer is one of the malignant tumors with the fastest growing incidence and mortality rates and poses the greatest threat to the health and lives of the population. In the past 50 years, many countries have reported a significant increase in the incidence and mortality of lung cancer, with men accounting for the first place in incidence and mortality of all malignant tumors, and women accounting for the second place in incidence and mortality. First, due to the occupation. This is because some jobs must be exposed to radioactive substances such as radium and uranium as well as mustard gas, asbestos, petroleum, asphalt, coal tar, arsenic, chromium, nickel, copper, tin, and other carcinogenic substances every day, which are the causes of lung cancer, and people who work in this area should pay more attention to lung cancer prevention. Secondly, due to chronic lung diseases. Some people do not know that they have chronic lung diseases, which may also be the cause of lung cancer, such as pneumoconiosis, silicosis, tuberculosis and so on. Once suffering from these lung diseases, the chances of developing lung cancer are high. If you want to carry out lung cancer prevention, you should be alert to these diseases as well. Moreover, if you suffer from lung fiber scar lesion or non-bronchial chronic inflammation will also slowly turn into lung cancer, which is also one of the causes of lung cancer. Thirdly, due to atmospheric pollution. Prevention of lung cancer requires improvement of air pollution. The incidence of lung cancer in many industrially developed countries is extremely high, and the incidence is higher in urban than rural areas, and higher in factories and mines than in residential areas. The main cause of lung cancer in this area is due to the pollution of the atmosphere by harmful substances such as benzopyrene carcinogenic hydrocarbons produced by burning oil, coal and internal combustion engines and asphalt road dust in industrial and transportation developed areas. Fourth, the home environment. The decoration materials of the house and the fumes from cooking contain many ulcer-causing substances, and passive smoking caused by smoking among family members can also pollute the small family environment. The cause of lung cancer in women may be related to the long-term inhalation of cooking fumes.