Tobacco smoke contains at least three dangerous chemicals: tar, nicotine and carbon monoxide. Tar is a mixture of several substances, which will be concentrated into a viscous substance in the lungs. Nicotine is an addictive drug, which is absorbed by the lungs and mainly affects the nervous system. Carbon monoxide reduces the ability of red blood cells to deliver oxygen to the whole body.
A person who smokes/kloc-0.5 to 20 cigarettes a day is four times more likely to develop lung cancer, oral cancer or laryngeal cancer and die than a non-smoker. The risk of dying from esophageal cancer is four times higher than that of non-smokers. The risk of dying from bladder cancer is twice as high; The risk of dying of heart disease is twice as high. Smoking is the main cause of chronic bronchitis and emphysema, and chronic lung disease itself will increase the risk of pneumonia and heart disease, and smoking will also increase the risk of hypertension. Harm of various organs:
Oral cavity and throat
Smoke (especially the tar contained in it) is a carcinogen-that is, it will cause cancer in the tissues it touches, so any part of the smoker's respiratory tract (including the mouth and throat) may cause cancer.
Heart and arteries
Nicotine can make the heart beat faster and blood pressure rise. Tobacco smoke may be caused by carbon monoxide, which seems to promote the accumulation of atherosclerosis. This condition is one of the causes of many heart diseases. Heavy smokers are much more likely to die of a heart attack than non-smokers.
esophagus
Most smokers like to swallow a certain amount of cigarettes, so the digestive tract (especially esophagus and pharynx) is at risk of cancer.
lung
Fine hairs arranged in the airway of the lung usually exclude hydrogen foreign bodies from the lung tissue. These villi will constantly sweep the particles in the lungs into phlegm or mucus and excrete them. In addition to causing cancer, the chemicals in tobacco smoke will gradually destroy some villi and increase mucus secretion, so there are chronic diseases in the lungs and bronchitis is also prone to infection. Obviously, the "smoker's cough" is due to the impairment of the mechanical efficiency of lung cleaning, so the amount of sputum has increased.
bladder
Bladder cancer may be caused by inhaling carcinogenic chemicals contained in tar, which are absorbed by the blood and then excreted through the urethra.
Damage to the skin
In fact, everyone knows the harm of smoking to the human body, but the harm of smoking to women, especially to the skin, is more aging, wrinkled and grayer than that of non-smoking women.
In particular, wrinkles in the corners of the eyes, upper and lower lips and corners of the mouth have increased significantly. Among them, smoking is more harmful to women's health than men's and will seriously affect the health of the next generation. So I advise you not to smoke.
Smoking will not only make facial skin wrinkle and yellow, but also have the same effect on the whole body skin. If you quit smoking, it may make your skin recover slowly. Yolanda Helfrich of the University of Michigan and others found that the number of cigarettes a person smokes every day and his age are directly related to the skin damage he experiences.
The researchers studied 82 volunteers, of whom 465,438+0 smoked and 465,438+0 did not smoke. Their ages range from 22 to 9 1 year. The researchers observed and photographed the inside of their upper limbs to show the quality of their skin. The results show that smokers over 65 have more wrinkles than non-smokers.
When the skin is exposed to the sun, mainly on the face, it will become rough, wrinkled and morbidly yellowish. Previous studies have also proved that smokers' facial skin will also be damaged like exposure to the sun.
However, this study by Helfrich et al. also proves that smoking will also cause the same damage to the body skin protected by clothes as the facial skin, which will lead to the aging of the whole body skin and the loss of elasticity and luster. Smoking leads to contraction of subcutaneous blood vessels and decreased blood supply to the skin. This may lead to skin damage and aging.
It is precisely because of smoking that the blood supply is reduced and the corresponding internal organs are damaged, such as arteries, kidneys and hearts. Another new study shows that smokers' arteries become hard because of tobacco poisoning, which leads to cardiovascular diseases such as elevated blood pressure.
Even after they quit smoking, it takes 10 years for blood vessels to return to normal. Moreover, smoking is harmful to others, and people who inhale smoke are more harmful than those who are smoking. Harm others and yourself, smoking is harmful.
Toxicity and Addiction of Nicotine
Nicotine is an odorous, bitter, colorless and transparent oily liquid, which is highly volatile, easily oxidized to dark gray in air, quickly soluble in water and alcohol, and easily absorbed by human body through nasal, oral and bronchial mucosa. Nicotine stuck to the skin surface can also be absorbed and penetrated into the body. Nicotine in one cigarette can poison a mouse, and nicotine in 20 cigarettes can poison a cow. The lethal dose of human is 50~70 mg, which is equivalent to the nicotine content of 20~25 cigarettes. If nicotine in a cigar or three cigarettes is injected into a person's vein for 3 to 5 minutes, he will die. Tobacco is not only harmful to higher animals, but also harmful to lower animals, so it is also the main component of agricultural pesticides. So "poisonous snakes don't bite smokers", because they smell the bitter taste of smoking, they run away. Similarly, passive smokers are uncomfortable with the smell of smoke.
Acute poisoning death caused by smoking has occurred in China. If you smoke too much, you will be drunk and spit yellow water on the ground and die. So Emperor Chongzhen once ordered a ban on smoking. It is also reported abroad that a young man in the Soviet Union smoked for the first time and died after smoking a big cigar. A 40-year-old healthy man who smokes for a long time in Britain is engaged in a very important job; I smoked 14 cigars and 40 cigarettes overnight. I felt sick in the morning and died after being rescued by a doctor. A French club held a smoking competition. The winner smoked 60 cigarettes and died before receiving the prize. Other participants were dying and went to the hospital for rescue.
So why do some people smoke a lot but are not poisoned? There are many people who smoke more than one box (20 cigarettes) every day, among which the nicotine content greatly exceeds the lethal dose of people, but few people die of acute poisoning, because some nicotine in tobacco is neutralized by formaldehyde, a poison in smoke, and most people do not smoke continuously, and these nicotine slowly enters the human body intermittently. In addition, 50% of nicotine diffuses into the air with smoke, 5% is thrown away with cigarette butts, 25% is destroyed by burning, and only 20% is absorbed by human body. Nicotine is rapidly detoxified in the body and excreted with urine. Coupled with long-term smokers, the body has tolerance and addiction to nicotine, making people addicted to cigarettes.
Why is smoking addictive?
When it comes to addictive substances, people often immediately think of opium, heroin, marijuana and other drugs, but forget the most used and harmful tobacco in the world. In fact, compared with heroin, except one is legal consumer goods and the other is contraband, there is almost no qualitative difference in other aspects, especially from the perspective of material dependence.
There are two main grounds for judging whether a substance is dependent in medicine. First, it depends on whether people have the characteristics of compulsory use and seeking this substance; The second is whether there is a strong desire to use a substance again after stopping using it and the corresponding behavior.
The so-called compulsory use and seeking means that it is already addictive and unnecessary. This sense of necessity is determined by the nature of addictive substances. That is to say, the fundamental reason for forcing addicts to quit smoking is physical dependence and mental dependence caused by long-term use of addictive substances, which is also known as withdrawal reaction, that is, after quitting smoking for dozens of minutes to several hours, they begin to want to smoke, feel restless, fidgety and at a loss, and then have headaches, palpitations, fatigue, abdominal discomfort, nausea, diarrhea, listlessness, difficulty in concentrating and hair-loving. All these symptoms make smokers more eager for tobacco. These symptoms are most prominent within three or four days after quitting smoking, and then gradually disappear around 1 month. But a few symptoms, such as difficulty in concentration and drowsiness, will last for a long time. Very similar to heroin and other drugs, once taken, all withdrawal symptoms can be relieved immediately, which is also the common feature of all addictive substances.
Scholars at home and abroad have done a lot of research on the mechanism of physical dependence and mental dependence. Some scholars let smokers smoke freely in the laboratory and give them different doses of nicotine or normal saline intravenously. It was found that subjects who ingested 4 mg nicotine per hour smoked 60% less than those who ingested normal saline. It shows that the desire and behavior of smoking are regulated by the nicotine content in human blood. The content of nicotine in tobacco is 0.5%~8%, which is mainly absorbed by respiratory mucosa. Nicotine in long-term smokers keeps a constant level, and the body has adapted to this state. Therefore, once you stop smoking, your nicotine level will drop, and smokers will feel all kinds of discomfort. Just like hypertension patients, once their blood pressure suddenly drops to normal, they will feel dizzy and all kinds of discomfort.
In addition, an interesting phenomenon is that when people are nervous or tired, they often unconsciously want to smoke in order to have a rest or relax. But in fact, smoking can make blood pressure rise, breathing excited and heart rate accelerate, which is just the opposite of what happens when people rest, but the subjective feeling of every smoker is really comfortable and relaxed. What is the reason? In fact, nicotine stimulates the secretion of adrenaline in the body, which can obviously increase the stress ability of the human body, thus improving the adaptability of people to external stimuli and leading to subjective relaxation.
The harm of smoking
The harm of smoking is well known. As many as 2.5 million people die from smoking every year in the world, and smoking is the first killer of mankind. Consciously developing the personal hygiene habit of not smoking is not only beneficial to health, but also the embodiment of noble public health ethics. In the smoking room, especially in the environment with closed doors and windows in winter, the room is not only filled with carbon dioxide exhaled by human body, but also with carbon monoxide exhaled by smokers, which will make people feel headache, burnout and work efficiency decline. More seriously, the contents of tar and nicotine in the cold smoke exhaled by smokers are 1 times higher than those in the hot smoke inhaled by smokers, and benzopyrene is 2 times higher, carbon monoxide is 4 times higher and ammonia is 50 times higher.
Some data show that the incidence of lung cancer, laryngeal cancer and coronary heart disease in long-term smokers is 10-20 times, 6- 10 times and 2-3 times higher than that in non-smokers respectively. The incidence of circulatory system is 3 times higher, and the incidence of tracheitis is 2-8 times higher. A survey was conducted in 1000 families, and it was found that children under 0/6 years old in smoking families/kloc-had more respiratory diseases than children in non-smoking families. Among children under 5 years old, 33.5% of non-smoking families have respiratory symptoms, and 44.5% of smoking families have respiratory symptoms.
Smoking is especially dangerous for women. If women who smoke are using oral contraceptives, they will increase the risk of heart disease and venous thrombosis of lower limbs. Pregnant women who smoke are prone to premature delivery and underweight, and the immune function of infants and young children is reduced, which is easy to get sick; According to statistics, the teratogenic rate of pregnant women's passive smoking infants has increased significantly.
Smoking harms others and yourself, so we should consciously develop good health habits of not smoking and create a smoke-free environment.