Despite the fact that most people know that smoking is a social nuisance and that it is harmful to health, the ranks of smokers are still growing, and there is a trend toward younger and more females. According to the results of a survey on the relationship between smoking and death conducted by Chinese and foreign medical scientists, which involved 1.25 million people in China, the number of deaths due to smoking is increasing dramatically among the male population in China. If current smoking conditions continue, China will face a massive epidemic of smoking-related diseases, with one-third of young men eventually dying from smoking or related diseases. In China, 2,000 people currently die every day from smoking or related diseases. Most of these are men. It is predicted that by 2025, the number of deaths from smoking will rise to 2 million per year; by 2050 it will increase to 3 million. Unfortunately, many people in China seriously underestimate the harmful effects of smoking; a national epidemiological survey of smoking behavior conducted in 1996 found that about two-thirds of people believed that smoking was minimally or not at all harmful, nearly 60% did not know that smoking could cause lung cancer, and 96% did not know that smoking could cause heart disease. In addition, according to the survey, at present, about 10-15% of 9-12 year olds in China smoke; about 35% of 12-15 year old middle and high school students smoke; 75% of high school and college students over 16 years old smoke. Nationally, the average age of smoking initiation was 3 years earlier in 1996 than in 1984. The youngest smokers were only 7 years old. The number of cigarettes smoked per capita per day: 1 in 1952, 4 in 1972, and 10 in 1992, and the number of female smokers has moved from a period of decline to a period of rebound, currently accounting for about 3% of smokers, with a trend toward youth. A large number of scientific experiments and clinical records show that tobacco contains a variety of harmful substances. Long-term smoking can stimulate and damage the mucous membrane of the larynx and trachea, causing coughing and phlegm, which eventually leads to chronic bronchitis, emphysema, pulmonary heart disease, etc. Because tobacco contains carcinogenic substances such as nitrosamines and arsenic, the incidence of lung cancer is much greater in smokers than in nonsmokers. In addition, smoking is the main cause of thrombotic vasculitis, but also make the risk of heart disease greatly increased. Smoking also accelerates aging and shortens life expectancy, and the younger you are when you start smoking, the greater the likelihood of dying from lung cancer in the future. What are the toxins in tobacco? What diseases can be caused by smoking? How does it poison the human body? Why are countries around the world taking measures to control smoking? Medical research in this area has never stopped. According to tests, the incomplete combustion process of cigarettes to occur in a series of thermal decomposition and thermal synthesis of chemical reactions, the formation of a large number of new substances, the harmful components of more than 3,000 kinds, including carcinogenic, carcinogenic substances on more than 30 kinds. People often say that nicotine, tobacco tar is only part of these toxic substances. To these two substances, for example, the former makes smokers addicted, and thus constantly victimized, the latter is through the deposition in the body, especially in the lungs, gradually become a “super killer”. Tests have shown that a cigarette contains nicotine can poison a mouse; 20 cigarettes of nicotine can poison a cow; human lethal amount is 50 mg-70 mg, equivalent to 20-25 cigarettes of nicotine content. If the nicotine from one cigar smoke or three cigarettes is injected into a person’s vein, it can kill in 3-5 minutes. Cigarette tar carcinogens and carcinogenic substances are polycyclic aromatic hydrocarbons and phenolic compounds, which can be deposited in the lungs and, after years of accumulation, may become cancerous. People who are 45 years old and have smoked for 20 years are 10 times more likely to develop lung cancer than non-smokers. The chemicals that are released when a cigarette is lit vary from cigarette to cigarette, but the main ones are tar and carbon monoxide. Cigarettes ignited to produce substances harmful to humans are broadly divided into six categories: 1, aldehydes, nitrides, olefins, these substances have an irritating effect on the respiratory tract. 2, nicotine, can stimulate sympathetic nerves, causing damage to the endothelium. 3, amines, cyanide and heavy metals, these are toxic substances. 4, benzpyrene, arsenic, cadmium, methylhydrazine, aminophenol, other radioactive substances. All of these substances have carcinogenic effects. 5.Phenolic compounds and formaldehyde, etc. These substances have the effect of accelerating carcinogenesis. 6, carbon monoxide can reduce the ability of red blood cells to transport oxygen to the whole body. A person who smokes 15 to 20 cigarettes a day, its susceptibility to lung cancer, oral cancer or laryngeal cancer to death than non-smokers 14 times greater; its susceptibility to esophageal cancer to death than non-smokers 4 times greater; the chances of dying from bladder cancer to be twice as large; the chances of dying from heart disease also to be twice as large. Cigarette smoking is a major cause of chronic bronchitis and emphysema (or chronic obstructive pulmonary disease, or COPD), and COPD itself increases the risk of pneumonia and heart disease, and smoking also increases the risk of high blood pressure. Cigarette smoke (especially the tar it contains) is a strong carcinogen – that is, it can produce cancer in the tissues it touches, so any part of a smoker’s respiratory tract (including the mouth and throat) is at risk for cancer. Nicotine can make the heart beat faster and blood pressure higher. Tobacco smoke, probably due to the presence of carbon monoxide, can contribute to the formation of atherosclerosis, which is a cause of many heart diseases, and people who smoke a lot have a much greater chance of dying from a heart attack than non-smokers. Smoking can also cause acute poisoning death, China has long been smoking more than the record fell to the ground and smoking led to the death of yellow water in the mouth, Chongzhen Emperor ordered a ban on smoking, the former Soviet Union had a young man smoked for the first time, after smoking a large cigar died. Britain, a long-term smoking 40-year-old healthy man, engaged in an important work, a night of 14 cigars and 40 cigarettes, the morning felt uncomfortable, by the doctor’s resuscitation died, a club in France held a smoking competition, the winner in he smoked 60 paper cigarettes, did not have time to receive the prize that died, the other participants in the competition are life-threatening, to hospital resuscitation. Smoking also causes social hazards and endangers public safety. Cases of fires caused by smoking and igniting or throwing unextinguished cigarette butts have been in the press, the most typical being the Daxinganling forest fire in May 1987. This fire caused a total of 6.913 billion yuan of heavy losses. It was later found that this huge forest fire, the initial five fires, four of them were caused by human beings, two of which were ignited by the cigarette butts of three “smokers”. Smoking also causes harm to pregnant women, pregnant women who smoke 15 to 20 cigarettes a day, their chances of miscarriage than non-smoking women twice as large, and more likely to give birth to premature babies or infants with a weakened constitution, smoking women born in the postpartum mortality rate of infants born than non-smoking women about 30% higher, and second-hand smoke, will increase the chances of non-smokers to get lung cancer, a survey in Britain showed that in A survey in the United Kingdom showed that in restaurants, bars, hotels and restaurants, secondhand smoke kills 49 staff each year, making 700 of the nation’s staff died of lung cancer, heart disease and stroke. Some brands of cigarettes are lower in tar and nicotine than others, but there is no completely safe cigarette in the world. So it’s not harmless to switch to “light” cigarettes. The human trachea and bronchi have cilia that normally remove foreign substances from the airways and lung tissue. In addition to causing cancer, the chemicals in tobacco smoke gradually destroy the cilia, causing inflammation in the trachea and bronchi and increasing mucus secretion, leading to chronic lung disease and microbial infections. Bladder cancer caused by smoking may be due to the inhalation of cancer-causing chemicals contained in tar, which are absorbed into the bloodstream and are then sampled in the urine. To date, there are more than 25 known tobacco-related diseases. The acute risks of tobacco include hypoxia, rapid heartbeat, shortness of breath, impotence, infertility, and increased serum carbon dioxide levels. The long-term harms of smoking are primarily illness and death, including heart attacks, strokes, lung cancer and other cancers. Studies have shown that smoking not only harms the smoker himself, but also endangers indirect smokers with many of the same diseases, especially in infants and young children causing acute death, respiratory disease and middle ear disease. The World Health Organization estimates that worldwide, more people will die from smoking-related diseases than from AIDS, tuberculosis, obstructed labor, car accidents, suicides, and homicides combined.