When it comes to addictive substances, people often immediately think of opium, heroin, marijuana and other drugs, but forget about the world’s most used and most harmful tobacco. In fact, compared to heroin, there is almost no qualitative difference in other aspects, except that one is a legal consumer product and the other is a contraband, especially from the perspective of substance dependence, both are the same. Tobacco has been prevalent around the world for more than two hundred years, and it was only in the 20th century that humans began to recognize the dangers of tobacco to humans. Studies have shown that the smoke produced by smoking contains many disease-causing substances, such as nicotine, nitrogen dioxide, hydrocyanic acid, acrolein, arsenic, lead, mercury and so on. According to foreign analysis, the concentration of the above-mentioned substances in smoke far exceeds the industrial licensing threshold, and the harm of cigarette smoke to the population even exceeds the chemical gases of industrial pollution. Smoking directly or indirectly leads to a variety of heart and brain diseases and respiratory diseases, and the incidence of a variety of malignant tumors increased significantly. The dangers of smoking are well known. However, compared with the harmful effects of active smoking, the harmful effects of passive smoking are often overlooked. A non-smoker who smokes for 15 minutes or more a day is considered a passive smoker. U.S. medical researchers recently published a study that passive smoking, commonly known as “secondhand smoke,” is more dangerous than originally known, and some women who live with smokers are six times more likely to develop lung cancer than the average person. The “GSTMI” gene, which is present in normal human tissue cells, is now thought to inactivate the carcinogens in tobacco. Women with mutations or deficiencies in this gene are 2.6 times to 6 times more likely to develop lung cancer than the general population. Fresh air, food and water are the most important factors for human life. In places where there is generally poor ventilation and more smokers, each milliliter of smoke contains 5 billion soot particles, which is 50,000 times more than the dust particles contained in normal air; the concentration of carbon monoxide exceeds 840 times the industrial allowable threshold, and the presence of large amounts of carbon monoxide makes people mentally tired and less productive, and the concentration of carboxyhemoglobin in the blood can rise to a moderate level of toxicity. The smoke emitted by smoking can be divided into mainstream smoke (i.e., smoke inhaled by the smoker into the mouth), and tributary smoke (i.e., smoke emitted from the outside of the tobacco ignition). Tributary smoke contains more tobacco combustion components than mainstream smoke. Tributary smoke contains five times more carbon monoxide than mainstream smoke; three times more tar and nicotine; four times more benzo(a)pyrene; 46 times more ammonia; and 50 times more nitrosamines. Many other harmful substances, including carcinogenic nitramines, are also inhaled in tributary smoke at concentrations greater than those inhaled from mainstream smoke. In addition, in tobacco smoke there is no original tobacco alkaloids in the high-temperature decomposition products, including halman and northeast halman, the main component of tryptophan, with psychoactive effects, the total amount of mainstream smoke per cigarette 15 to 20 mg. Of course, smoke from the tributary smoke in the air has been diluted, in fact, passive inhalation of smoke is always less than the smoker inhaled. However, in the national smokers have reached more than 300 million people in the situation, few people can get rid of this smoke attack. According to calculations, in poorly ventilated places, non-smokers inhaled smoke in an hour, the average equivalent of inhaling a cigarette dose. China has become the world’s largest producer and consumer of tobacco, the annual consumption of tobacco accounted for more than 1/3 of the world’s total sales; according to population calculations, the number of people currently smoking in China is 400 million, while the number of young smokers is as high as 5 million. Currently, about 1 million people die each year in China from smoking-related illnesses, and the Chinese government pays up to $7 billion each year for medical treatment of smoking-related diseases. By 2020, the number of smoking-related deaths in China will reach 2 million per year! Even more alarming is the fact that more than 600 million people in China are suffering from passive smoking under the smoky blanket of more than 400 million smokers. These hundreds of millions of “non-smokers”, daily by the fog of poison, over time, part of the “non-smokers”, will also get lung cancer and other diseases, and become “smokers” of victims. This shows that smoking has become a public health problem that seriously affects the health of the general public in China. Not only try not to smoke, but also do not allow yourself to inhale “second-hand smoke”, even in public places should also try to avoid those who swallow fog, in order to avoid the danger of “second-hand smoke”. In November 1987, the United Nations World Health Organization recommended that April 7 of each year be designated as World No Tobacco Day, which was implemented in 1988. Since 1989, World No Tobacco Day has been observed on May 31 each year. The purpose of the campaign is to remind the world that smoking is harmful to health, to call on smokers around the world to give up smoking voluntarily, and to call on all tobacco producers, sellers and the entire international community to act together and join the anti-smoking campaign to create a tobacco-free environment for humanity. Lorraine Flint of the National Health Service in the UK said: “Smoking is a major problem. Flint said: “Neither smokers nor non-smokers are fully aware of the harmful effects of indirect smoking. Tobacco contains about 4,000 different chemicals, and more than 50 of them, including arsenic, formaldehyde and ammonia, have been found to cause cancer. If we do not pay attention to this fact and smokers smoke in front of others, the risk of causing disease is greatly increased. We organized this event to show people that often those places we think are the safest may be the most dangerous, like the home where we watch TV and rest.” Flint said, “We hope this campaign will provide smokers with the best reason to quit – to protect your family, friends and co-workers. By making everyone aware that indirect smoking is truly harmful, smokers are motivated to quit for the sake of everyone’s health.” For your personal health and for the public good of all society, please quit!