Harm to smoking: questions and answers. Part 1.

Harm to smoking: questions and answers. How many cigarettes do you have to smoke a day in order to have health problems in the future? Does it make sense to switch to "light" cigarettes to reduce the harm of smoking? What is a "natural cigarette"? Is the harm of smoking menthol cigarettes really less than the harm of smoking ordinary cigarettes? What happens in the body when it gets nicotine? What toxic substances are contained in cigarette smoke, in addition to nicotine? How strong is tobacco smoking? What severe disease causes tobacco smoking? Why there is a "cough smoker"? How dangerous is secondhand smoke? What actually causes cancer when smoking tobacco?

Many have questions about smoking tobacco, the answers to which are sometimes difficult to find. These questions can concern smoking cigarettes, cigars, the use of other tobacco products, as well as dependence on nicotine and ways to quit smoking. This article contains answers to many of these questions. We will tell you about the severity of the harm done to people by smoking, as well as about how smoking and tobacco affect health (including cardiac activity, circulation and lungs). Let's talk about the harm that tobacco causes a child when a pregnant woman smokes. Let's talk about why the risk of getting cancer and other diseases is higher for smokers than for non-smokers.

Can I smoke without harm to my health?

No you can not. All cigarettes are harmful to health. Any kind of smoking is dangerous and harmful. Cigarettes are the only product that is widely advertised and actively offered to the public, although everyone knows that the harm of smoking for health is extremely dangerous, and that smoking leads to cancer.

Some people try to reduce the harm of smoking, smoking as few cigarettes a day as possible, but for most smokers it is quite difficult. According to the results of scientific research, even if a person smokes 1 to 4 cigarettes a day, in the future this leads to serious health problems, including an increased risk of heart attack and death at a young age.

Some people are sure that if you prefer cigarettes with a high content of nicotine and tar so-called "light" cigarettes, in which less harmful substances, the harm of smoking that is applied to the body will decrease, but they are mistaken. When a person accustomed to "heavy" ie. "strong" cigarettes, goes to lighter cigarettes, he often begins to smoke more cigarettes than before, or simply deeper tightens, and as a result his body receives the same dose of nicotine as before.

Producers of tobacco products were able to convince smokers that the harm of smoking "light" cigarettes is not so strong for health, and that switching to such cigarettes can help stop smoking. Alas, this is not so! Cigarettes with a low content of nicotine and tar are just as harmful as ordinary cigarettes, because when smoking such cigarettes, many smokers are drawn deeper and more often, and also smoked a cigarette almost to the filter, which also does not contribute to reducing the harm of smoking. Scientific research has shown that the risk of developing lung cancer is the same for those who smoke ordinary "strong" cigarettes and those who prefer "light" cigarettes.

There is an opinion that the so-called "cigarettes", that is, homemade cigarettes made from tobacco wrapped in a smoking paper, are safer and cheaper than regular cigarettes, but in fact the harm of smoking such "scooters" is no less than the harm of smoking conventional cigarettes that are produced by tobacco companies. According to clinical studies, those who smoke "cigarettes", laryngeal cancer (the body responsible for a person's ability to speak out loud), the esophagus (the organ that connects the mouth and stomach), the oral cavity and pharynx develops more often than those who smoke ordinary cigarettes.

Not so long ago, so-called "natural" cigarettes appeared on sale. Manufacturers argue that these cigarettes do not contain harmful chemicals and impurities, and their filters are made of pure cotton. However, there is as yet no evidence that the harm of smoking these cigarettes for health is less than the harm of smoking other cigarettes. At the same time, there really is no reason to believe that this is really so. The smoke of these cigarettes, like the smoke of any other tobacco products, contains various carcinogenic substances and toxins that are formed during the burning of tobacco, including tar and carbon monoxide.

With regard to herbal cigarettes, even if they do not contain tobacco, they still have harmful to the resin and carbon monoxide. Thus, smoking without harm to health is impossible.

Is it true that the harm of smoking menthol cigarettes is less than the harm of smoking conventional cigarettes?

Menthol cigarettes are no less harmful than other cigarettes. In fact, they are even more harmful than ordinary cigarettes. Menthol, which is added to tobacco, gives a feeling of mint coolness when tightened, and also reduces the cough reflex and neutralizes the feeling of dryness in the throat, which often affects smokers. Therefore, those people who smoke menthol cigarettes, can deeper tighten and longer hold smoke in the lungs. As a result, the harm of smoking menthol cigarettes is nothing less than the harm of smoking ordinary cigarettes.

About a quarter of all cigarettes sold in the US are menthol. They are especially popular with black Americans. According to the latest research data, those who smoke menthol cigarettes are less likely to quit smoking, and those who still try to quit are harder to give than cigarette smokers. One of the researchers involved in the problem of smoking, said that those people who smoke menthol cigarettes, you must first go to regular cigarettes, and then try to quit smoking. In this case, the chances of successfully getting rid of this bad habit are increasing.

Smoking is dependency?

Yes it is. The harm of smoking is that nicotine, which is contained in cigarettes, causes dependence on cigarettes. Nicotine is a strong enough drug, the use of which leads to the development of strong addiction and dependence, as well as the use of heroin and cocaine. About how much the drugs are really harmful, you can find out in the corresponding section "Harm of drugs" .

• When small doses of nicotine enter the body, the smoker has pleasant sensations that cause the desire to continue smoking. The emergence of these sensations is associated with the processes occurring in the brain and central nervous system, as a result of which the smoker's mood is elevated and the effect of improving well-being appears. And the harm of smoking in such moments of pleasure of the smoker excites the least. The scheme of the effect of nicotine on the brain is about the same as that of other drugs - it increases the concentration in the brain of dopamine, a chemical substance that is also known as the "pleasure hormone", resulting in a reflex in the human body that connects the use of nicotine with pleasant sensations . Nicotine also increases the level of adrenaline in the blood - it's almost imperceptible, but it leads to an increase in heart rate and increase in blood pressure.
• Nicotine enters the brain cells within just a few seconds after tightening, but the effect of its use disappears in a few minutes, which often causes the smoker to smoke another cigarette. If a person who is addicted to smoking can not get his usual dose, he develops a "withdrawal syndrome", quite severe and painful.
• On average, one cigarette is enough for 10 puffs. Thus, people who smoke a pack of cigarettes a day receive about 200 nicotine "micro-hits" daily.
• In most cases, smokers develop nicotine addiction, and when they stop using nicotine, they suffer from withdrawal symptoms - both at the physiological and psychological levels. These symptoms include irritability, nervousness, headaches and poor sleep. However, the root of dependence is that people continue to smoke, even knowing how harmful it is to health, is life-threatening, and also realizing the harm done by smoking to their family members. Most smokers would like to get rid of their bad habits.

Currently, many researchers are trying to find out whether tobacco contains other chemicals, other than nicotine, that lead to the development of smoking addiction. Data have been obtained on changes in the brain structure of experimental animals under the influence of tobacco smoke, but it was found that these changes were caused not only by nicotine, but also by some other substances, so the research continues.

How does nicotine act on the body?

In large doses, nicotine becomes a deadly poison and can cause death from stopping breathing. However, smokers use nicotine in small amounts, which are quickly neutralized by the body and are removed from it. The first dose of nicotine per day causes a feeling of cheerfulness and emotional uplift, and the subsequent - a sense of calm and relaxation.

The damage to smoking in beginner smokers, as well as those who smoked too many cigarettes in a row, often manifests itself in the fact that people begin to feel sick, and some have abdominal pain. The heart rate of those who smoke for the first time, increases by 2-3 beats per minute in comparison with the norm. Nicotine also lowers body temperature and prevents normal blood circulation between the body and limbs, which leads to an increased risk of heart disease and stroke.

Many people mistakenly believe that nicotine causes cancer, so do not dare to try to quit using cigarette substitutes containing nicotine (patches, pills, etc.). The harm of smoking is actually strong and nicotine causes dependence on smoking, but the cancer itself in smokers develops under the influence of other toxic substances contained in tobacco smoke. Experiments on animals have shown that under the action of nicotine, tumors that already existed in the body can begin to grow and develop, but it is not yet clear whether the nicotine has the same effect on the human body.

Why do people start smoking?

Many start smoking during adolescence, out of curiosity or following the example of friends and classmates. Those who smoke parents and / or close friends, become smokers more often than those in whose environment no one smokes.

Another important social factor that encourages people to try smoking is active advertising of tobacco products, reduction of prices for cigarettes in the framework of advertising campaigns and other marketing activities of tobacco companies. Of course, there is no information about the fact that the harm of smoking can manifest itself in a person in the form of a whole complex of severe illnesses. Companies of the tobacco industry spend billions of dollars each year to create a user-friendly image of a smoker and to set smoking as an aesthetically attractive, interesting and safe occupation. Despite the fact that in 1998 an official decision was made to ban the display of cigarettes in films, still in 3 of the 4 highest grossing films, the characters are smoking - and yet a third of these films are intended for teenagers and young people. According to the results of sociological research, teenagers who see scenes of smoking in movies are more likely to start smoking themselves than their peers who have never seen such scenes.

What groups of people are most susceptible to developing dependence on nicotine?

Anyone who starts smoking gets significant harm from smoking and can become addicted to tobacco. Scientific research shows that teenagers are getting used to smoking most quickly. The earlier a person starts smoking, the faster his dependence on nicotine develops. About 90% of adult smokers smoked their first cigarette when they were not yet 19 years old. There are even those who tried to smoke as a child.

How many people smoke?

The percentage of smokers among the adult population of the United States declined from 42% in 1965 to 21% in 2008 (more recent data are not yet available). Today, about 46 million American adults regularly smoke tobacco. In 2008, 23% of men and 18% of women smoked. It can also be assumed that the percentage of smokers in society is affected by the level of education received - in social groups with a higher education level, smokers are less.

Is smoking common among young people?

Yes. According to the latest government research data, among American teenagers and young people there is widespread use of tobacco products, not only cigarettes, but also chewing and snuff.

Despite the fact that recently there has been a tendency to reduce the number of young people who use tobacco products, the harm of smoking does not become weaker. So in 2007, according to the results of sociological research, 1 out of 3 (that is, 30%) of university students used tobacco products during the last month. For female students this indicator was 1 out of 5, that is 21%. Half (about 50%) of students who use tobacco products reported that they tried to quit smoking during the past year. Also among students of higher educational institutions, smoking cigars is popular (about 14% of students).

As for the pupils of the senior classes, about 19% of them regularly use tobacco products, most often cigarettes (6%). Young people consume tobacco products more often than girls - this applies to all types of tobacco products, except for cigarettes, which are equally popular among young people of both sexes. In addition, the harm of smoking has another effect. A high percentage of people who smoke among young people often leads to serious social problems. According to statistics, smoking young men and girls are also more likely to use various drugs, aggressive behavior, illegal carrying of arms, suicide and promiscuous sexual relations.

Why is cigarette smoke so harmful?

The damage to smoking is so strong, because the smoke that the smoker inhales into himself contains incredibly poisonous substances. Cigarette smoke is a complex chemical compound arising from the combustion of tobacco and substances added to it in the manufacture of tobacco products. Tobacco smoke contains tar, which contains more than 4,000 chemicals, 60 of which are carcinogenic. Some of these substances cause deadly diseases of the heart and lungs. It may be hard to believe, but according to scientific research, tobacco smoke contains the following extremely hazardous chemicals.

• Cyanide (potassium cyanide)
• Benzene
• Formaldehyde
• Methanol (wood alcohol)
• Acetylene (fuel used in welding torches)
• Ammonia

The composition of tobacco smoke also includes toxic gases - carbon dioxide and carbon monoxide (carbon monoxide). And, of course, in the smoke there is nicotine - a drug and an active ingredient that causes dependence on tobacco.

In addition, the tobacco leaves from which cigarettes are made contain radioactive substances. The concentration of these substances depends on the soil on which the plants were grown, and on the fertilizers that were used for their sub-feeding. Thus, the harm of smoking is also caused by radiation, since tobacco smoke is a radioactive compound that smokers breathe when tightened. Particles of radioactive substances settle in the lungs, and after a while their concentration becomes very dangerous for health. Moreover, it is the radioactive substances, according to doctors, which can be the cause of the frequent development of lung cancer in smokers.

Is it true that smoking leads to cancer?

Yes, the harm of smoking is manifested in the fact that smoking leads to cancer. About 30% of people who died of cancer in the US were smokers. In 87% of patients with lung cancer, smoking became the cause of the disease. Also, smoking can cause cancer of the larynx, mouth, pharynx, esophagus and diaphragm. In addition, according to some reports, smoking people are more likely to develop cancer of the pancreas, cervix, kidneys, stomach and some types of blood cancer. Smoking of cigars, pipes, and also the use of chewing and snuffing tobacco also causes the development of cancer. Safe ways of using tobacco does not exist!

What is the harm of smoking caused by cigarette smoke?

Usually, the harm of smoking does not take long to wait and smoking people are rapidly developing lung health problems. Thus, the level of pulmonary activity in smokers is lower than that of non-smokers. As people continue to regularly smoke tobacco, these problems are aggravated. Smoking leads to the development of many lung diseases, among which there are deadly, including lung cancer. Among chronic pulmonary diseases, which affect smokers, most often there is chronic bronchitis and emphysema. These diseases cause difficulties with breathing and oxygen supply to the lungs, which can lead to a serious threat to life, and in some cases even death.

Chronical bronchitis

Chronic bronchitis is a disease in which the person's airways produce excessive amounts of mucus, and the patient must constantly expectorate it. The harm of smoking is incredibly often manifested in the fact that very many smokers suffer from chronic bronchitis. In their lungs, too much mucus accumulates, with which the respiratory tract can not cope - they swell, and the cough becomes permanent, and the drugs almost do not help. Дыхательные пути больного забиваются слизью и не могут нормально функционировать, так как они сильно воспалены. В результате возникает риск развития опаснейших лёгочных инфекций.

Эмфизема

Курение является одной из главных причин развития эмфиземы лёгких – страшной болезни, в результате которой человек постепенно теряет способность дышать. Кислород поступает в кровь через лёгкие, впитываясь через их дыхательную поверхность, состоящую из множества маленьких пузырьков. Вред курения проявляется в том, что у больного эмфиземой разрушаются стенки этих пузырьков и, таким образом, пузырьки становятся больше, но их количество снижается. В результате сокращается площадь дыхательной поверхности лёгких, и в кровь поступает меньшее количество кислорода. По мере того, как болезнь прогрессирует, площадь дыхательной поверхности становится настолько маленькой, что больной может умереть от удушья, вызванного нехваткой кислорода.

Самые первые признаки эмфиземы – это одышка, особенно в лежачем положении, постоянный кашель, от которого не помогают лекарства (так называемый "кашель курильщика"), чувство общей усталости, иногда снижение веса. Кроме того, вред курения выражается в том, что из-за слабости лёгких больные эмфиземой подвержены риску других серьёзных заболеваний, к примеру, пневмонии. На поздних стадиях болезни пациенты могут нормально дышать только с помощью кислородной трубки или маски. Эмфизема неизлечима, однако её развитие можно приостановить, особенно, если больной бросит курить.

Хроническое обструктивное заболевание лёгких

Более 10 миллионов жителей США страдают от хронического обструктивного заболевания лёгких (ХОЗЛ) – этим медицинским термином обозначается сочетание хронического бронхита и эмфиземы. В США хроническое обструктивное заболевание лёгких находится на четвертом месте в списке заболеваний, наиболее часто приводящих к летальному исходу. От ХОЗЛ чаще умирают женщины, чем мужчины. Основной фактор риска развития ХОЗЛ – это курение; более 75% людей, умерших от ХОЗЛ, были курильщиками. Помимо ужасных страданий, которые переживают больные в период развития заболевания, вред курения особенно коварно проявляется на последней стадии. Последняя стадия заболевания является крайне мучительной для больных – они всё время страдают от нехватки воздуха и чувствуют себя так, как будто тонут и при этом не могут дышать.

Почему курящие люди страдают от "кашля курильщика"?

Сигаретный дым содержит различные химические вещества и вредоносные частицы, которые раздражают альвеолы и лёгочную ткань. Когда курящий человек вдыхает эти вещества вместе с дымом, организм старается защититься и вырабатывает слизь, которая потом требует выхода путём отхаркивания. Обычно курильщики страдают от кашля по утрам – этому есть несколько объяснений. При нормальном функционировании организма клетки ресничного эпителия, который выстилает полость лёгких (крошечные образования, похожие на волоски) выводят из лёгких слизь, мокроту и другие вещества, однако сигаретный дым нарушает этот процесс, поэтому в лёгких остаются вредные вещества, содержащиеся в табачном дыме, а также слизь. Пока курящий человек спит, клетки ресничного эпителия восстанавливают свои функции и вновь начинают работать, и поэтому, когда курильщик просыпается, то начинает кашлять – это результат попытки организма вывести из лёгких всё лишнее. Если человек курит на протяжении долгого времени, то вред курения оказывается настолько мощным, что клетки лёгочного эпителия вообще перестают работать, и лёгкие становятся ещё больше подвержены инфекционным заболеваниям и раздражению от табачного дыма.

Существует ли вред курения, если при курении не вдыхать дым?

Да, вред курения без затяжек почти также силён, как и вред курения с затягиванием дыма в лёгкие. Табачный дым причиняет вред не только лёгким, но и любой клетке организма при соприкосновении с ней. Даже если курящий человек не вдыхает дым, в его лёгкие попадают вторичные продукты горения табака, что также повышает риск развития рака лёгких. У тех, кто курит трубку и сигары и, соответственно, почти не затягивается при курении, часто бывает рак губы, ротовой полости, языка и т.п.

Насколько вред курения опасен для сердца?

Вред курения крайне опасен для сердца. Курение невероятно повышает риск развития сердечных заболеваний, которые являются наиболее распространённой причиной смерти среди жителей не только США, но и других стран. К факторам риска относится также высокое кровяное давление, повышенный уровень холестерина в крови, малоподвижный образ жизни и диабет, однако именно курение чаще всего становится причиной сердечных приступов.

Курящий человек, у которого случился сердечный приступ, с большей вероятностью умрёт в течение часа после приступа, чем некурящий. Даже если человек курит очень редко, и количество никотина, поступающего в его организм, не приводит к развитию лёгочных заболеваний, то вред курения проявляется в том, что риск болезней сердца всё равно значительно повышается по сравнению с теми людьми, кто не курит и никогда не курил.

Как курение влияет на беременных женщин и их будущих детей?

Женщины, которые продолжают курить во время беременности, невероятно рискуют здоровьем и жизнью своих малышей. Вред курения для курящей женщины может быть просто чудовищным. Если женщина курит во время беременности, у неё возрастает риск выкидыша, преждевременных родов, рождения мёртвого ребенка, смерти ребёнка сразу после рождения, рождения больного ребёнка или развития у него так называемого синдрома внезапной смерти новорожденного. Около 5% случаев детских смертей можно было бы избежать, если бы матери этих детей не курили во время беременности.

Когда беременная женщина курит, она причиняет вред не только себе, но и ребёнку. Никотин, окись углерода и другие вредные химические вещества попадают в её кровь, а затем в тело ребенка, что препятствует поступлению в его организм кислорода и питательных веществ, необходимых для нормального развития плода. Кроме того, кормление грудью – это самый лучший и естественный способ питания новорожденного ребёнка, однако если кормящая мать курит, то никотин и другие ядовитые вещества отравляют ребёнка, попадая в его организм с грудным молоком. Это может вызвать у ребёнка беспокойство, проблемы со сном, учащённое сердцебиение, расстройство желудка.

According to some studies, children whose mothers smoked during pregnancy or were near to people who smoke, then worse in school, and may lag behind in growth and development from children of non-smoking mothers. In addition, in adolescence, these children are more likely to start smoking themselves.

What health problems can smoking lead to and how quickly do they develop?

Smoking is the cause of many cancers, but cancer is just one of many deadly diseases that develop in people who smoke. Harm of smoking can manifest itself as a whole complex of diseases. Those who smoke for a long time are more likely to have heart disease, aneurysm (vasodilation), various types of bronchitis, emphysema and stroke. In addition, smoking leads to an exacerbation of asthma and the development of chronic pneumonia. Smokers heal longer wounds and cuts on the body, and the immunity is much lower than that of non-smokers.

Smoking also causes severe damage to the arteries, so many surgeons refuse to do patients with peripheral arterial diseases (impaired blood circulation in the hands and feet) until they quit smoking. The longer men smoke, the higher their risk of impotence (erectile dysfunction).

It is established that smoking people live less than non-smokers. According to the results of studies conducted by specialists of the Center for Disease Control and Prevention in the late 1990s, the harm of smoking is manifested in the fact that smoking reduces life expectancy by 13.2 years for men and by 14.5 years for women. Smoking men and women die more often in middle age (35-69 years) than those who have never smoked.

Smoking harms health and in the short term - for example, leads to disruption of the normal functioning of the lungs, which causes many smokers to suffer from shortness of breath and cough. Smoking people quickly become tired with physical activity. Smoking reduces sensitivity to tastes and smells, leads to premature aging of the skin, causes bad breath and darkening of the teeth.

What is the probability of death from smoking?

About half of smoking people die from diseases caused by smoking. In the United States, smoking is the cause of 1 out of every 5 deaths; Every year, 443,600 US residents die from smoking-related illnesses. Smoking is the only cause of fatal diseases, which is relatively easy to prevent.

According to the researchers' forecasts, about 650 million people living now can die from diseases caused by smoking tobacco. If the trend towards an increase in the number of smokers in the world continues, the harm of smoking will be so global that by 2030 the number of deaths from diseases caused by smoking will increase from 5.4 million deaths per year (the figure that is considered relevant right now) to 10 million. According to doctors, the death rate from diseases caused by smoking will be the highest in developing countries.

What is the danger of secondhand smoke?

Passive or secondary smoking is a term used in medicine to describe a situation in which a non-smoker has to breathe smoke from cigarettes of those people who smoke next to him. Passive smoking involves inhaling the so-called "main" smoke (the smoke that the smoker inhales into the lungs and then exhales) and the "by-side" smoke (the smoke that forms during the burning of the cigarette). With passive smoking, the same harmful substances get into the body of a non-smoker, as in the body of a smoker.

The results of scientific research show that passive smoking causes serious damage to health. Annually about 3400 non-smoking adult people die from lung cancer, and 46,000 people die from heart diseases caused by second-hand smoke. The damage to smoking in passive smokers is manifested in the fact that they may experience asthma and other respiratory tract diseases, eye mucosa irritation, headaches, nausea and dizziness. Children whose parents smoke often suffer from asthma, inflammation of the lungs, bronchitis, inflammation of the middle ear, and also suffer from other respiratory diseases more often. The children of smokers are more prone to the sudden death syndrome of newborns. In pregnant women who have been passive smokers, sick children are more likely to be born, and the risk of miscarriage and premature birth increases.

Can passive smoking lead to breast cancer?

Currently, scientists are trying to find out whether it's true that passive smoking increases the risk of breast cancer. Both primary and secondary smoke contains about 20 harmful chemical compounds, large doses of which cause breast cancer in rodents on which scientific experiments were conducted. Chemicals contained in tobacco easily reach the breast tissue and can then be found in breast milk.

The relationship between secondhand smoke and an increased risk of breast cancer in women is not exactly established, in particular, because the relationship between active smoking and breast cancer has not yet been proven. However, scientists do not exclude the possibility that passive and active smoking can actually cause breast cancer in women.

According to the report of the California Environmental Protection Agency, published in 2005, second-hand smoke can lead to breast cancer, especially in young women. In some cases of cancer, which were considered by scientists, there is a high probability that it was passive smoking that triggered the development of the disease. The US Department of Health report of 2006, entitled "Harm of passive smoking for health", said that the link between passive smoking and breast cancer "is possible, but not yet proven." In 2007, the California Environmental Protection Agency published another report, in which the agency's experts stated that "the cause of the development of breast cancer in some young women who are of reproductive age could be likely to become regular second-hand smoke, since others possible causes of the disease is not found. " Currently, scientists continue to research, since an exact answer has not yet been received, but the assumption that passive smoking causes breast cancer can be an excellent argument for women to try to avoid passive smoking.

Is there a risk of developing cancer, inhaling the smell of cigarette smoke that remains on the smoker's clothing, or in a smoke-filled room?

At present, there is no confirmed data on the development of cancers by the smell of tobacco smoke, but it has been proved that with passive smoking smoke absorbs into hair, clothes, etc. Some researchers use the term "tertiary smoking" to refer to the harmful effects on human health of tobacco smoke particles that remain in the air after the smoke has disappeared. Despite the fact that the results of the study of the effects of tertiary smoking on health are still unknown, it can be assumed that the degree of risk of developing cancer from this type of second-hand smoke is significantly lower than from second-hand smoking, for example, from living in the same apartment with a smoker. However, at present, scientists are actively engaged in studying the effect of tertiary smoking on the health of non-smokers.

The second part of the article is read here: "The Harm of Smoking: Questions and Answers, Part 2."

Source of material for the article: "Questions About Smoking, Tobacco, and Health" .