Bronchial lung cancer (lung cancer for short) is one of the most common malignant tumors around the world nowadays, and the mortality rate has ranked first among cancers. 2007, the annual incidence of lung cancer in China reached 60/100,000, and there is an increasing trend, making China the world’s largest lung cancer country. The prevention and treatment of lung cancer has become the main task of our thoracic surgeons. And most of such patients have a long and extensive history of smoking and passive smoking. Therefore, it is necessary to popularize the hazards of smoking to the general public so as to reduce the occurrence of lung cancer under the new concept of prevention-oriented health. ”A cigarette after a meal is better than a living god”, “morning tea and evening wine after dinner smoke”, smoking people are always looking for various excuses for their “swallowing clouds and spitting fog”. A few teenagers out of curiosity, or by the influence of people around smoking, often in the case of “suck in the play”, learned to smoke, and over time to develop a hobby. In fact, smoking has a hundred harms but no benefit. Cigarettes by burning decomposition, can be decomposed out of a variety of substances, of which there are about 30 kinds of carcinogenic or cancer-promoting effect. One of the nicotine, as long as the intake of 50 mg can make adults dead. It is estimated that if one smokes 30 cigarettes a day, the annual dose of alpha radiation exposure to the human body is equivalent to the dose accumulated from 100 x-rays. This irradiation affects the metabolism of tissue cells, causing cellular genetic mutations that induce and promote the formation and development of cancer; smoking causes a decrease in NK cell activity, and the more one smokes, the less active they become. Data show that heavy smokers who accumulate more than 150 packs of cigarettes per year have significantly lower NK cell activity than nonsmokers. The incidence of various cancers is 7-11 times higher in smokers than in nonsmokers, and lung cancer is more closely related to smoking. The risk of lung cancer in smokers is 13 times higher than in nonsmokers, and increases to 45 times if they smoke more than 35 cigarettes per day. Statistics show that the more cigarettes smoked per day, the younger the age of starting to smoke, the longer the years of smoking, and the higher the tar content of tobacco, the greater the risk of cancer induction. The incidence of lung cancer in smokers who smoke more than 25 cigarettes per day is 250/100,000. Smokers can also cause indoor air pollution, making most people passive smokers. In recent years it has been proven that passive smokers have a much higher risk of developing lung cancer. Studies have proven that if the husband smokes and the wife does not smoke in a family and often live together, the chance of the wife getting lung cancer in the future is twice to three times higher than if the husband does not smoke. The more the husband smokes, the greater the chance of the wife getting cancer. If someone in the family smokes, the children in the family are likely to get bronchitis and pneumonia. According to U.S. statistics, 83% of lung cancers in the United States are caused by smoking. Those who smoke more than 40 cigarettes a day have a lung cancer mortality rate 15-20 times higher than that of smokers. In addition, the number of lung cancer deaths caused by passive smoking increases greatly every year. The fact that smoking is harmful and that smoking is prone to cancer is indisputable. Not only does smoking harm you, but it also harms those who are closest to you. In 1985, a Swedish court decided that smoking by co-workers could cause lung cancer and death among co-workers, and called the phenomenon “occupational injury” for which the victim’s family could claim a certain amount of financial compensation. According to statistics, the annual number of deaths caused by passive smoking is 1000 in the UK and 4000-5000 in the US. Advice: smoking is really “harmless” to humans, whether I or second-hand smokers, will cause great harm to the body, so I advise addicts, for the sake of their own health and the health of others, please quit smoking immediately!