Numerous studies have shown that smoking, especially paper cigarette smoking, is the leading cause of progressive increases in lung cancer mortality. Smoking is associated with most cancers, and according to statistics, there are currently 1.3 billion smokers worldwide, and 5 million people die each year from smoking-related diseases. Benzo(a)pyrene, nicotine, nitrosamines, carbon monoxide and a small amount of radioactive elements such as polonium in cigarette smoke are carcinogenic, and are especially likely to cause squamous epithelial cell carcinoma and undifferentiated small cell carcinoma. Compared with nonsmokers, the risk of lung cancer is 9-10 times higher on average for smokers, and up to 10-25 times higher for heavy smokers. There is a clear quantitative-effect relationship between the amount of smoking and lung cancer, the younger the age of starting smoking, the longer the time of smoking, and the greater the amount of smoking, the higher the incidence of lung cancer. Director Liu Xinyan of Hebei Chest Hospital reminds you that the cancer risk of one cigarette is equivalent to 0.01-0.04mGy of radiation, and smoking 30 paper cigarettes per day is equivalent to 1.2mGy of radiation dose. Passive smoking or environmental smoking is also a cause of lung cancer, with an increased risk of 20-30%. The risk of lung cancer among non-smoking wives whose husbands smoke is twice as high as that of wives in households where both spouses do not smoke, and the risk increases with the amount of smoking by the husband. What is encouraging is that the risk of lung cancer decreases year by year after quitting smoking, and it can be halved after 1-5 years of quitting. Director Liu Xinyan told the audience that studies in the United States have shown that the risk of lung cancer decreases progressively between 2 and 15 years after quitting smoking, after which the incidence rate is equivalent to that of a lifelong nonsmoker. The Chinese Ministry of Health recently released the 2007 China Smoking Control Report, which pointed out that China has about 300 million smokers, but 540 million people are suffering from passive smoking, including 180 million children under the age of 15, and more than 100,000 people die from passive smoking each year. The World Health Organization decided to designate May 31 each year as “World No Tobacco Day” since 1989.