With the increasing incidence and mortality of lung cancer in China, the World Health Organization (WHO) predicts that by 2025, China will have more than 1 million new cases of lung cancer each year, making it the world’s largest lung cancer country. At the same time, according to the latest report of China Anti-Cancer Association and China Cancer Foundation, lung cancer is caused by “gas”. So, what exactly is the reason for saying so? Tobacco contains hundreds of harmful substances, including 69 carcinogenic substances, which not only cause lung cancer, but also have a great impact on other malignant tumors, cardiovascular diseases, respiratory diseases, digestive diseases and reproductive diseases. With the increase of age and the extension of smoking age, the oncogenes and oncogenes in the body gradually lose balance, and the chance of cancer increases. Second, the oil gas: kitchen fumes is an important element of indoor air pollution. When cooking oil is heated to 170 ℃ there will be a small amount of smoke, 250 ℃ there will be a lot of oil smoke. When frying, deep-frying, stir-frying and barbecuing, the oil temperature will be above 260 ℃, the cooking process, the fumes produced by benzo(a)pyrene, volatile nitrosamines, etc. will bring great harm to human health. The greater the cooking fumes, the longer the exposure time, the greater the risk of lung cancer. Air pollution: With the gradual increase of hazy weather, more and more people are familiar with the term PM2.5, which is a kind of fine particulate matter caused by fossil fuel coal, oil, etc. and garbage burning. These fine particles can directly enter the alveolar tissue through bronchi and fine bronchioles, and carry harmful substances and carcinogens in the atmosphere into the blood. Anger: When people are in a bad mental state for a long time, it may directly lead to the occurrence of cancer. Usually, we call this behavior as a kind of “psychological pollution” and this personality as “cancer personality”. Therefore, experts say that in our daily life, we should keep cheerful and calm, and relieve stress and bad emotions through proper exercise, so that we can stay away from “cancer personality” and be a healthy person physically and mentally.