Smoking's history dates back to as early as 5000–3000 BC when the agricultural product began to be cultivated in South America; consumption later evolved into burning the plant substance either by accident or with intent of exploring other means of consumption. The practice worked its way into shamanistic rituals. Many ancient civilisations — such as the Babylonians, the Indians, and the Chinese — burnt incense during religious rituals. The practice was later adopted by the Catholic and the Orthodox churches. Smoking in the Americas probably had its origins in the incense-burning ceremonies of shamans but was later adopted for pleasure or as a social tool. The smoking of tobacco and various hallucinogenic drugs was used to achieve trances and to come into contact with the spirit world.
Eastern North American tribes would carry large amounts of tobacco in pouches as a readily accepted trade item and would often smoke it in pipes, either in sacred ceremonies or to seal bargains. Adults as well as children enjoyed the practice. It was believed that tobacco was a gift from the Creator and that the exhaled tobacco smoke was capable of carrying one's thoughts and prayers to heaven
Apart from smoking, tobacco had a number of uses as medicine. As a pain killer it was used for earache and toothache and occasionally as a poultice. Smoking was said by the desert Indians to be a cure for colds, especially if the tobacco was mixed with the leaves of the small Desert Sage, Salvia Dorrii, or the root of Indian Balsam or Cough Root, Leptotaenia multifida, the addition of which was thought to be particularly good for asthma and tuberculosis
Selasa, 01 Mei 2012
the definition of tobacco
The active substances in tobacco, especially cigarettes, are administered by burning the leaves and inhaling the vaporised gas that results. This quickly and effectively delivers substances into the bloodstream by absorption through the alveoli in the lungs. The lungs contain some 300 million alveoli, which amounts to a surface area of over 70 m2 (about the size of a tennis court). This method is not completely efficient as not all of the smoke will be inhaled, and some amount of the active substances will be lost in the process of combustion, pyrolysis. Pipe and Cigar smoke are not inhaled because of its high alkalinity, which are irritating to the trachea and lungs. However, because of its higher alkalinity (pH 8.5) compared to cigarette smoke (pH 5.3), non-ionised nicotine is more readily absorbed through the mucous membranes in the mouth. Nicotine absorption from cigar and pipe, however, is much less than that from cigarette smoke.
The inhaled substances trigger chemical reactions in nerve endings. The cholinergic receptors are often triggered by the naturally occurring neurotransmitter acetylcholine. Acetylcholine and Nicotine express chemical similarities, which allows Nicotine to trigger the receptor as well. These nicotinic acetylcholine receptors takes are located in the central nervous system and at the nerve-muscle junction of skeletal muscles; whose activity increases heart rate, alertness, and faster reaction times. Nicotine acetylcholine stimulation is not directly addictive. However, since dopamine-releasing neurons are abundant on nicotine receptors, dopamine is released. This release of dopamine, which is associated with pleasure, is reinforcing and may also increase working memory.Nicotine and cocaine activate similar patterns of neurons, which supports the idea that common substrates among these drugs.
When tobacco is smoked, most of the nicotine is pyrolyzed. However, a dose sufficient to cause mild somatic dependency and mild to strong psychological dependency remains. There is also a formation of harmane (a MAO inhibitor) from the acetaldehyde in tobacco smoke. This may play a role in nicotine addiction, by facilitating a dopamine release in the nucleus accumbens as a response to nicotine stimuli. Using rat studies, withdrawal after repeated exposure to nicotine results in less responsive nucleus accumbens cells, which produce dopamine responsible for reinforcement.
The inhaled substances trigger chemical reactions in nerve endings. The cholinergic receptors are often triggered by the naturally occurring neurotransmitter acetylcholine. Acetylcholine and Nicotine express chemical similarities, which allows Nicotine to trigger the receptor as well. These nicotinic acetylcholine receptors takes are located in the central nervous system and at the nerve-muscle junction of skeletal muscles; whose activity increases heart rate, alertness, and faster reaction times. Nicotine acetylcholine stimulation is not directly addictive. However, since dopamine-releasing neurons are abundant on nicotine receptors, dopamine is released. This release of dopamine, which is associated with pleasure, is reinforcing and may also increase working memory.Nicotine and cocaine activate similar patterns of neurons, which supports the idea that common substrates among these drugs.
When tobacco is smoked, most of the nicotine is pyrolyzed. However, a dose sufficient to cause mild somatic dependency and mild to strong psychological dependency remains. There is also a formation of harmane (a MAO inhibitor) from the acetaldehyde in tobacco smoke. This may play a role in nicotine addiction, by facilitating a dopamine release in the nucleus accumbens as a response to nicotine stimuli. Using rat studies, withdrawal after repeated exposure to nicotine results in less responsive nucleus accumbens cells, which produce dopamine responsible for reinforcement.
production of tobacoo
products
Tobacco is an agricultural product processed from the fresh leaves of plants in the genus Nicotiana. The genus contains a number of species, however, Nicotiana tabacum is the most commonly grown. Nicotiana rustica follows as second containing higher concentrations of nicotine. These leaves are harvested and cured to allow for the slow oxidation and degradation of carotenoids in tobacco leaf. This produces certain compounds in the tobacco leaves which can be attributed to sweet hay, tea, rose oil, or fruity aromatic flavors. Before packaging, the tobacco is often combined with other additives in order to: enhance the addictive potency, shift the products pH, or improve the effects of smoke by making it more palatable. In the United States these additives are regulated to 599 substances. The product is then processed, packaged, and shipped to consumer markets. Means of consumption has greatly expanded in scope as new methods of delivering the active substances with fewer by-products have encompassed or are beginning to encompass:
Field of tobacco organized in rows extending to the horizon.
Tobacco field in Intercourse, Pennsylvania.
Powderly stripps hung vertically, slightly sun bleached.
Basma leaves curing in the sun at Pomak village of Xanthi, Thrace, Greece.
Rectangular strips stacked in an open square box.
Processed tobacco pressed into long strips for shipping.
Beedi
Beedis are thin South Asian cigarettes filled with tobacco flake and wrapped in a tendu leaf tied with a string at one end. They produce higher levels of carbon monoxide, nicotine, and tar than cigarettes typical in the United States.
Cigars
Cigars are tightly rolled bundles of dried and fermented tobacco which are ignited so that smoke may be drawn into the smoker's mouth. They are generally not inhaled because the high alkalinity of the smoke, which can quickly become irritating to the trachea and lungs. The prevalence of cigar smoking varies depending on location, historical period, and population surveyed, and prevalence estimates vary somewhat depending on the survey method. The United States is the top consuming country by far, followed by Germany and the United Kingdom; the US and Western Europe account for about 75% of cigar sales worldwide. As of 2005 it is estimated that 4.3% of men and 0.3% of women smoke cigars in USA.
Cigarettes
Cigarettes, French for "small cigar", are a product consumed through smoking and manufactured out of cured and finely cut tobacco leaves and reconstituted tobacco, often combined with other additives, which are then rolled or stuffed into a paper-wrapped cylinder. Cigarettes are ignited and inhaled, usually through a cellulose acetate filter, into the mouth and lungs.
Electronic cigarette
Electronic cigarettes are an alternative to tobacco smoking, although no tobacco is consumed. It is a battery-powered device that provides inhaled doses of nicotine by delivering a vaporized propylene glycol/nicotine or vegetable glycerin/nicotine solution. Many legislation and public health investigations are currently pending in many countries due to its relatively recent emergence. Most electronic cigarettes are designed to resemble actual tobacco smoking implements, such as cigarettes, cigars, or pipes, but many take the form of ballpoint pens or screwdrivers since those designs are more practical to house the mechanisms involved. Most are also reusable, with replaceable and refillable parts, but some models are disposable.
French inhale
The French inhale is the action performed by smokers of expelling smoke from the mouth and inhaling it into the nostrils.
Hookah
Hookah are a single or multi-stemmed (often glass-based) water pipe for smoking. Originally from India. The hookah was a symbol of pride and honour for the landlords, kings and other such high class people. Now,the hookah has gained immense popularity, especially in the Middle East. A hookah operates by water filtration and indirect heat. It can be used for smoking herbal fruits, tobacco, or cannabis.
Kretek
Kretek are cigarettes made with a complex blend of tobacco, cloves and a flavoring "sauce". It was first introduced in the 1880s in Kudus, Java, to deliver the medicinal eugenol of cloves to the lungs. The quality and variety of tobacco play an important role in kretek production, from which kretek can contain more than 30 types of tobacco. Minced dried clove buds weighing about 1/3 of the tobacco blend are added to add flavoring. In 2004 the United States prohibited cigarettes from having a "characterizing flavor" of certain ingredients other than tobacco and menthol, thereby removing kretek from being classified as cigarettes.
Passive smoking
Passive smoking is the usually involuntary consumption of smoked tobacco. Second-hand smoke (SHS) is the consumption where the burning end is present, environmental tobacco smoke (ETS) or third-hand smoke is the consumption of the smoke that remains after the burning end has been extinguished. Because of its perceived negative implications, this form of consumption has played a central role in the regulation of tobacco products.
Pipe smoking
Pipe smoking typically consists of a small chamber (the bowl) for the combustion of the tobacco to be smoked and a thin stem (shank) that ends in a mouthpiece (the bit). Shredded pieces of tobacco are placed into the chamber and ignited. Tobaccos for smoking in pipes are often carefully treated and blended to achieve flavour nuances not available in other tobacco products.
Roll-Your-Own
Roll-Your-Own or hand-rolled cigarettes, often called 'rollies', are very popular particularly in European countries. These are prepared from loose tobacco, cigarette papers, and filters all bought separately. They are usually much cheaper than ready-made cigarettes.
Vaporizer
A vaporizer is a device used to sublimate the active ingredients of plant material. Rather than burning the herb, which produces potentially irritating, toxic, or carcinogenic by-products; a vaporizer heats the material in a partial vacuum so that the active compounds contained in the plant boil off into a vapor. Medical administration of a smoke substance often prefer this method as to directly pyrolyzing the plant material.
Tobacco is an agricultural product processed from the fresh leaves of plants in the genus Nicotiana. The genus contains a number of species, however, Nicotiana tabacum is the most commonly grown. Nicotiana rustica follows as second containing higher concentrations of nicotine. These leaves are harvested and cured to allow for the slow oxidation and degradation of carotenoids in tobacco leaf. This produces certain compounds in the tobacco leaves which can be attributed to sweet hay, tea, rose oil, or fruity aromatic flavors. Before packaging, the tobacco is often combined with other additives in order to: enhance the addictive potency, shift the products pH, or improve the effects of smoke by making it more palatable. In the United States these additives are regulated to 599 substances. The product is then processed, packaged, and shipped to consumer markets. Means of consumption has greatly expanded in scope as new methods of delivering the active substances with fewer by-products have encompassed or are beginning to encompass:
Field of tobacco organized in rows extending to the horizon.
Tobacco field in Intercourse, Pennsylvania.
Powderly stripps hung vertically, slightly sun bleached.
Basma leaves curing in the sun at Pomak village of Xanthi, Thrace, Greece.
Rectangular strips stacked in an open square box.
Processed tobacco pressed into long strips for shipping.
Beedi
Beedis are thin South Asian cigarettes filled with tobacco flake and wrapped in a tendu leaf tied with a string at one end. They produce higher levels of carbon monoxide, nicotine, and tar than cigarettes typical in the United States.
Cigars
Cigars are tightly rolled bundles of dried and fermented tobacco which are ignited so that smoke may be drawn into the smoker's mouth. They are generally not inhaled because the high alkalinity of the smoke, which can quickly become irritating to the trachea and lungs. The prevalence of cigar smoking varies depending on location, historical period, and population surveyed, and prevalence estimates vary somewhat depending on the survey method. The United States is the top consuming country by far, followed by Germany and the United Kingdom; the US and Western Europe account for about 75% of cigar sales worldwide. As of 2005 it is estimated that 4.3% of men and 0.3% of women smoke cigars in USA.
Cigarettes
Cigarettes, French for "small cigar", are a product consumed through smoking and manufactured out of cured and finely cut tobacco leaves and reconstituted tobacco, often combined with other additives, which are then rolled or stuffed into a paper-wrapped cylinder. Cigarettes are ignited and inhaled, usually through a cellulose acetate filter, into the mouth and lungs.
Electronic cigarette
Electronic cigarettes are an alternative to tobacco smoking, although no tobacco is consumed. It is a battery-powered device that provides inhaled doses of nicotine by delivering a vaporized propylene glycol/nicotine or vegetable glycerin/nicotine solution. Many legislation and public health investigations are currently pending in many countries due to its relatively recent emergence. Most electronic cigarettes are designed to resemble actual tobacco smoking implements, such as cigarettes, cigars, or pipes, but many take the form of ballpoint pens or screwdrivers since those designs are more practical to house the mechanisms involved. Most are also reusable, with replaceable and refillable parts, but some models are disposable.
French inhale
The French inhale is the action performed by smokers of expelling smoke from the mouth and inhaling it into the nostrils.
Hookah
Hookah are a single or multi-stemmed (often glass-based) water pipe for smoking. Originally from India. The hookah was a symbol of pride and honour for the landlords, kings and other such high class people. Now,the hookah has gained immense popularity, especially in the Middle East. A hookah operates by water filtration and indirect heat. It can be used for smoking herbal fruits, tobacco, or cannabis.
Kretek
Kretek are cigarettes made with a complex blend of tobacco, cloves and a flavoring "sauce". It was first introduced in the 1880s in Kudus, Java, to deliver the medicinal eugenol of cloves to the lungs. The quality and variety of tobacco play an important role in kretek production, from which kretek can contain more than 30 types of tobacco. Minced dried clove buds weighing about 1/3 of the tobacco blend are added to add flavoring. In 2004 the United States prohibited cigarettes from having a "characterizing flavor" of certain ingredients other than tobacco and menthol, thereby removing kretek from being classified as cigarettes.
Passive smoking
Passive smoking is the usually involuntary consumption of smoked tobacco. Second-hand smoke (SHS) is the consumption where the burning end is present, environmental tobacco smoke (ETS) or third-hand smoke is the consumption of the smoke that remains after the burning end has been extinguished. Because of its perceived negative implications, this form of consumption has played a central role in the regulation of tobacco products.
Pipe smoking
Pipe smoking typically consists of a small chamber (the bowl) for the combustion of the tobacco to be smoked and a thin stem (shank) that ends in a mouthpiece (the bit). Shredded pieces of tobacco are placed into the chamber and ignited. Tobaccos for smoking in pipes are often carefully treated and blended to achieve flavour nuances not available in other tobacco products.
Roll-Your-Own
Roll-Your-Own or hand-rolled cigarettes, often called 'rollies', are very popular particularly in European countries. These are prepared from loose tobacco, cigarette papers, and filters all bought separately. They are usually much cheaper than ready-made cigarettes.
Vaporizer
A vaporizer is a device used to sublimate the active ingredients of plant material. Rather than burning the herb, which produces potentially irritating, toxic, or carcinogenic by-products; a vaporizer heats the material in a partial vacuum so that the active compounds contained in the plant boil off into a vapor. Medical administration of a smoke substance often prefer this method as to directly pyrolyzing the plant material.
policies of tobacco
In Germany, anti-smoking groups, often associated with anti-liquor groups, first published advocacy against the consumption of tobacco in the journal Der Tabakgegner (The Tobacco Opponent) in 1912 and 1932. In 1929, Fritz Lickint of Dresden, Germany, published a paper containing formal statistical evidence of a lung cancer–tobacco link. During the Great depression Adolf Hitler condemned his earlier smoking habit as a waste of money, and later with stronger assertions. This movement was further strengthened with Nazi reproductive policy as women who smoked were viewed as unsuitable to be wives and mothers in a German family.
The anti-tobacco movement in Nazi Germany did not reach across enemy lines during the Second World War, as anti-smoking groups quickly lost popular support. By the end of the Second World War, American cigarette manufacturers quickly reentered the German black market. Illegal smuggling of tobacco became prevalent,and leaders of the Nazi anti-smoking campaign were silenced.As part of the Marshall Plan, the United States shipped free tobacco to Germany; with 24,000 tons in 1948 and 69,000 tons in 1949. Per capita yearly cigarette consumption in post-war Germany steadily rose from 460 in 1950 to 1,523 in 1963.By the end of the 20th century, anti-smoking campaigns in Germany were unable to exceed the effectiveness of the Nazi-era climax in the years 1939–41 and German tobacco health research was described by Robert N. Proctor as "muted".
A lengthy study conducted in order to establish the strong association necessary for legislative action.
In 1950, Richard Doll published research in the British Medical Journal showing a close link between smoking and lung cancer. Beginning in December 1952, the magazine Reader's Digest published "Cancer by the Carton", a series of articles that linked smoking with lung cancer.
In 1954, the British Doctors Study, a study of some 40 thousand doctors over 20 years, confirmed the suggestion, based on which the government issued advice that smoking and lung cancer rates were related. In January 1964, the United States Surgeon General's Report on Smoking and Health likewise began suggesting the relationship between smoking and cancer.
As scientific evidence mounted in the 1980s, tobacco companies claimed contributory negligence as the adverse health effects were previously unknown or lacked substantial credibility. Health authorities sided with these claims up until 1998, from which they reversed their position. The Tobacco Master Settlement Agreement, originally between the four largest US tobacco companies and the Attorneys General of 46 states, restricted certain types of tobacco advertisement and required payments for health compensation; which later amounted to the largest civil settlement in United States history.
From 1965 to 2006, rates of smoking in the United States declined from 42% to 20.8%. The majority of those who quit were professional, affluent men. Although the per-capita number of smokers decreased, the average number of cigarettes consumed per person per day increased from 22 in 1954 to 30 in 1978. This paradoxical event suggests that those who quit smoked less, while those who continued to smoke moved to smoke more light cigarettes. The trend has been paralleled by many industrialized nations as rates have either leveled-off or declined. In the developing world, however, tobacco consumption continues to rise at 3.4% in 2002.[7] In Africa, smoking is in most areas considered to be modern, and many of the strong adverse opinions that prevail in the West receive much less attention. Today Russia leads as the top consumer of tobacco followed by Indonesia, Laos, Ukraine, Belarus, Greece, Jordan, and China.
Consumption
The anti-tobacco movement in Nazi Germany did not reach across enemy lines during the Second World War, as anti-smoking groups quickly lost popular support. By the end of the Second World War, American cigarette manufacturers quickly reentered the German black market. Illegal smuggling of tobacco became prevalent,and leaders of the Nazi anti-smoking campaign were silenced.As part of the Marshall Plan, the United States shipped free tobacco to Germany; with 24,000 tons in 1948 and 69,000 tons in 1949. Per capita yearly cigarette consumption in post-war Germany steadily rose from 460 in 1950 to 1,523 in 1963.By the end of the 20th century, anti-smoking campaigns in Germany were unable to exceed the effectiveness of the Nazi-era climax in the years 1939–41 and German tobacco health research was described by Robert N. Proctor as "muted".
A lengthy study conducted in order to establish the strong association necessary for legislative action.
In 1950, Richard Doll published research in the British Medical Journal showing a close link between smoking and lung cancer. Beginning in December 1952, the magazine Reader's Digest published "Cancer by the Carton", a series of articles that linked smoking with lung cancer.
In 1954, the British Doctors Study, a study of some 40 thousand doctors over 20 years, confirmed the suggestion, based on which the government issued advice that smoking and lung cancer rates were related. In January 1964, the United States Surgeon General's Report on Smoking and Health likewise began suggesting the relationship between smoking and cancer.
As scientific evidence mounted in the 1980s, tobacco companies claimed contributory negligence as the adverse health effects were previously unknown or lacked substantial credibility. Health authorities sided with these claims up until 1998, from which they reversed their position. The Tobacco Master Settlement Agreement, originally between the four largest US tobacco companies and the Attorneys General of 46 states, restricted certain types of tobacco advertisement and required payments for health compensation; which later amounted to the largest civil settlement in United States history.
From 1965 to 2006, rates of smoking in the United States declined from 42% to 20.8%. The majority of those who quit were professional, affluent men. Although the per-capita number of smokers decreased, the average number of cigarettes consumed per person per day increased from 22 in 1954 to 30 in 1978. This paradoxical event suggests that those who quit smoked less, while those who continued to smoke moved to smoke more light cigarettes. The trend has been paralleled by many industrialized nations as rates have either leveled-off or declined. In the developing world, however, tobacco consumption continues to rise at 3.4% in 2002.[7] In Africa, smoking is in most areas considered to be modern, and many of the strong adverse opinions that prevail in the West receive much less attention. Today Russia leads as the top consumer of tobacco followed by Indonesia, Laos, Ukraine, Belarus, Greece, Jordan, and China.
Consumption
inventor of the tobacco
n 1612, six years after the settlement of Jamestown, John Rolfe was credited as the first settler to successfully raise tobacco as a cash crop. The demand quickly grew as tobacco, referred to as "brown gold", reviving the Virginia joint stock company from its failed gold expeditions. In order to meet demands from the Old World, tobacco was grown in succession, quickly depleting the soil. This became a motivator to settle west into the unknown continent, and likewise an expansion of tobacco production. Indentured servitude became the primary labor force up until Bacon's Rebellion, from which the focus turned to slavery. This trend abated following the American revolution as slavery became regarded as unprofitable. However, the practice was revived in 1794 with the invention of the cotton gin.
Frenchman Jean Nicot (from whose name the word nicotine is derived) introduced tobacco to France in 1560, and tobacco then spread to England. The first report of a smoking Englishman is of a sailor in Bristol in 1556, seen "emitting smoke from his nostrils". Like tea, coffee and opium, tobacco was just one of many intoxicants that was originally used as a form of medicine. Tobacco was introduced around 1600 by French merchants in what today is modern-day Gambia and Senegal. At the same time caravans from Morocco brought tobacco to the areas around Timbuktu and the Portuguese brought the commodity (and the plant) to southern Africa, establishing the popularity of tobacco throughout all of Africa by the 1650s.
Soon after its introduction to the Old World, tobacco came under frequent criticism from state and religious leaders. Murad IV, sultan of the Ottoman Empire 1623-40 was among the first to attempt a smoking ban by claiming it was a threat to public moral and health. The Chinese emperor Chongzhen issued an edict banning smoking two years before his death and the overthrow of the Ming dynasty. Later, the Manchu of the Qing dynasty, who were originally a tribe of nomadic horse warriors, would proclaim smoking "a more heinous crime than that even of neglecting archery". In Edo period Japan, some of the earliest tobacco plantations were scorned by the shogunate as being a threat to the military economy by letting valuable farmland go to waste for the use of a recreational drug instead of being used to plant food crops
Frenchman Jean Nicot (from whose name the word nicotine is derived) introduced tobacco to France in 1560, and tobacco then spread to England. The first report of a smoking Englishman is of a sailor in Bristol in 1556, seen "emitting smoke from his nostrils". Like tea, coffee and opium, tobacco was just one of many intoxicants that was originally used as a form of medicine. Tobacco was introduced around 1600 by French merchants in what today is modern-day Gambia and Senegal. At the same time caravans from Morocco brought tobacco to the areas around Timbuktu and the Portuguese brought the commodity (and the plant) to southern Africa, establishing the popularity of tobacco throughout all of Africa by the 1650s.
Soon after its introduction to the Old World, tobacco came under frequent criticism from state and religious leaders. Murad IV, sultan of the Ottoman Empire 1623-40 was among the first to attempt a smoking ban by claiming it was a threat to public moral and health. The Chinese emperor Chongzhen issued an edict banning smoking two years before his death and the overthrow of the Ming dynasty. Later, the Manchu of the Qing dynasty, who were originally a tribe of nomadic horse warriors, would proclaim smoking "a more heinous crime than that even of neglecting archery". In Edo period Japan, some of the earliest tobacco plantations were scorned by the shogunate as being a threat to the military economy by letting valuable farmland go to waste for the use of a recreational drug instead of being used to plant food crops
history of tobacco
Tobacco smoking is the practice where tobacco is burned and the resulting smoke (consisting of particle and gaseous phases) is inhaled. The practice may have begun as early as 5000–3000 BC. Tobacco was introduced to Eurasia in the late 16th century where it followed common trade routes. The practice encountered criticism from its first import into the Western world onwards, but embedded itself in certain strata of a number of societies before becoming widespread upon the introduction of automated cigarette-rolling apparatus.
German scientists identified a link between smoking and lung cancer in the late 1920s, leading to the first anti-smoking campaign in modern history, albeit one truncated by the collapse of the Third Reich at the end of the Second World War In 1950, British researchers demonstrated a clear relationship between smoking and cancer. Scientific evidence continued to mount in the 1980s, which prompted political action against the practice. Rates of consumption since 1965 in the developed world have either peaked or declined. However, they continue to climb in the developing world.
Smoking is the most common method of consuming tobacco, and tobacco is the most common substance smoked. The agricultural product is often mixed with additives and then pyrolyzed. The resulting smoke is then inhaled and the active substances absorbed through the alveoli in the lungs. The active substances trigger chemical reactions in nerve endings, which heighten heart rate, alertness, and reaction time. Dopamine and endorphins are released, which are often associated with pleasure. As of 2000, smoking is practiced by approximately 1.22 billion people. In most communities men are more likely to smoke than are women, though the gender gap tends to be less pronounced in lower age groups.
Many smokers begin during adolescence or early adulthood. During the early stages, a combination of perceived pleasure acting as positive reinforcement and desire to respond to social peer pressure may offset the unpleasant symptoms of initial use, which typically include nausea and interrupted sleep patterns. After an individual has smoked for some years, the avoidance of withdrawal symptoms and negative reinforcement become the key motivations to continue.
German scientists identified a link between smoking and lung cancer in the late 1920s, leading to the first anti-smoking campaign in modern history, albeit one truncated by the collapse of the Third Reich at the end of the Second World War In 1950, British researchers demonstrated a clear relationship between smoking and cancer. Scientific evidence continued to mount in the 1980s, which prompted political action against the practice. Rates of consumption since 1965 in the developed world have either peaked or declined. However, they continue to climb in the developing world.
Smoking is the most common method of consuming tobacco, and tobacco is the most common substance smoked. The agricultural product is often mixed with additives and then pyrolyzed. The resulting smoke is then inhaled and the active substances absorbed through the alveoli in the lungs. The active substances trigger chemical reactions in nerve endings, which heighten heart rate, alertness, and reaction time. Dopamine and endorphins are released, which are often associated with pleasure. As of 2000, smoking is practiced by approximately 1.22 billion people. In most communities men are more likely to smoke than are women, though the gender gap tends to be less pronounced in lower age groups.
Many smokers begin during adolescence or early adulthood. During the early stages, a combination of perceived pleasure acting as positive reinforcement and desire to respond to social peer pressure may offset the unpleasant symptoms of initial use, which typically include nausea and interrupted sleep patterns. After an individual has smoked for some years, the avoidance of withdrawal symptoms and negative reinforcement become the key motivations to continue.
Minggu, 29 April 2012
posting munggaran
akhirnya ..... jadi juga ini blog, dan seterusnya saya akan banyak bercerita tentang Mole, apa itu mole ? .. nantikan posting saya berikutya.
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