Tobacco smoking

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Tobacco smoking is the practice where tobacco is burned and the vapors either tasted or inhaled. The practice began as early as 5000–3000 BC.^[1] Many civilizations burnt incense during religious rituals, which was later adopted for pleasure or as a social tool.^[2] Tobacco was introduced to the old world in the late 1500s where it followed common trade routes. The substance was met with frequent criticism, but became popular nonetheless.^[3] German scientists formally identified the link between smoking and lung cancer in the late 1920s leading the first anti-smoking campaign in modern history. The movement, however, failed to reach across enemy lines during the Second World War, and quickly became unpopular thereafter.^[4] In 1950, health authorities again began to suggest a relationship between smoking and cancer.^[5] Scientific evidence mounted in the 1980s, which prompted political action against the practice. Rates of consumption from 1965 onward in the developed world have either peaked or declined.^[6] They however continue to climb in the developing world.^[7]

Smoking is the most common method of consuming tobacco, and tobacco is the most common substance smoked. The agricultural product is often mixed with other additives^[8] and then pyrolyzed. The resulting vapors are then inhaled and the active substances absorbed through the alveoli in the lungs.^[9] The active substances trigger chemical reactions in nerve endings which hightens heart rate, memory, alertness,^[10] and reaction time.^[11] Dopamine and later endorphins are released, which are often associated with reward and pleasure.^[12] As of 2000, smoking is practiced by some 1.22 billion people. Men are more likely to smoke than women,^[13] however the gender gap declines with younger age.^[14][15] The poor are more likely to smoke than the wealthy, and people of developing countries than those of developed countries.^[7]

Many smokers begin during adolescence or early adulthood. During the early stages, smoking provides pleasurable sensations and thus serves as a source of positive reinforcement. After an individual has smoked for many years, the avoidance of withdrawal symptoms and negative reinforcement become the key motivations.

History

Early use

Aztec women are handed flowers and smoking tubes before eating at a banquet, Florentine Codex, 16th century.

The history of smoking 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.^[1] The practice worked its way into shamanistic rituals.^{[16][page needed]} Many ancient civilizations, such as the Babylonians, Indians and Chinese, burnt incense as a part of religious rituals, as did the Israelites and the later Catholic and Orthodox Christian 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.^[2] 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 defined ceremonies that were considered sacred, or to seal a bargain,^[17] and they would smoke it at such occasions in all stages of life, even in childhood.^{[18][page needed]} 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.^[19]

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.^[20]

Popularization

A Persian girl smoking by Muhammad Qasim. Isfahan, 1600s

In 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 join stock company from its failed gold expeditions.^[21] 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.^[22] Indentured servitude became the primary labor force up until Bacon's Rebellion, from which the focus turned to slavery.^[23] 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.^{[24][page needed]}

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".^[3] Like tea, coffee and opium, tobacco was just one of many intoxicants that was originally used as a form of medicine.^[25] 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.^[26]

Bonsack's cigarette rolling machine, as shown on U.S. patent 238,640.

Religious leaders have often been prominent among those who considered smoking immoral or outright blasphemous. In 1634 the Patriarch of Moscow forbade the sale of tobacco and sentenced men and women who flaunted the ban to have their nostrils slit and their backs whipped until skin came off their backs. The Western church leader Urban VII likewise condemned smoking in a papal bull of 1642. Despite many concerted efforts, restrictions and bans were almost universally ignored. When James I of England, a staunch anti-smoker and the author of a A Counterblaste to Tobacco, tried to curb the new trend by enforcing a 4000% tax increase on tobacco in 1604, it proved a failure, as London had some 7,000 tobacco sellers by the early 1600s. Later, scrupulous rulers would realise the futility of smoking bans and instead turned tobacco trade and cultivation into lucrative government monopolies.^[27][28]

By the mid-1600s every major civilization had been introduced to tobacco smoking and in many cases had already assimilated it into the native culture, despite the attempts of many rulers to eliminate the practice with harsh penalties or fines. Tobacco, both product and plant, followed the major trade routes to major ports and markets, and then on into the hinterlands. The English language term smoking was coined in the late 1700s; before then the practice was called drinking smoke.^{[3][page needed]}

Growth remained stable until the American Civil War in 1860s, when the primary labor force shifted from slavery to share cropping. This, along with a change in demand, lead to the industrialization of tobacco production with the cigarette. James Bonsack, a craftsman, in 1881 produce a machine to speed the production in cigarettes.^[29]

Social stigma

A Nazi anti-smoking ad titled "The chain-smoker" saying "He does not devour it [the cigarette], it devours him"

In Germany, anti-smoking groups, often associated with anti-liquor groups,^[30] 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,^[31] 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.^[32]

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 manufactures quickly reentered the German black market. Illegal smuggling of tobacco became prevalent,^[33] and leaders of the Nazi anti-smoking campaign were silenced.^[34] 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.^[33] Per capita yearly cigarette consumption in post-war Germany steadily rose from 460 in 1950 to 1,523 in 1963.^[4] By the end of the 1900s, anti-smoking campaigns in Germany was 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".^[4]

A lengthy study conducted in order to establish the strong association necessary for legislative action.

Richard Doll in 1950 published research in the British Medical Journal showing a close link between smoking and lung cancer.^[35] Four years later, 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.^[5] In 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.^[36]

From 1965 to 2006, rates of smoking in the United States have declined from 42% to 20.8%.^[6] The majority of those who quit in were professional, affluent men. Despite this decrease in the prevalence of consumption, 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.^[37] 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.^[38] Today Russia leads as the top consumer of tobacco followed by Indonesia, Laos, Ukraine, Belarus, Greece, Jordan, and China.^[39]

Consumption

Methods

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 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.^[8] 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:

Beedi

Beedis are thin, often flavored, South Asian cigarette made of tobacco wrapped in a tendu leaf, and secured with colored thread at one end.^{[citation needed]} Bidis smoke produce higher levels of carbon monoxide, nicotine, and tar than cigarettes typical in the United States.^[40][41] Due to the relatively low cost of beedies compared with regular cigarettes, they have long been popular among the poor in Bangladesh, Pakistan, Sri Lanka, Cambodia and India.^{[citation needed]}

Cigars

Cigars are tightly rolled bundle of dried and fermented tobacco which is ignited so that its 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. Instead they are generally drawn into the mouth.^{[citation needed]} 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.^[42] As of 2005 it is estimated that 4.3% of men and 0.3% of women smoke cigars.^[43]

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.^[8] Cigarettes are ignited and inhaled, usually through a cellulose acetate filter, into the mouth and lungs. Cigarette smoking is the most common method of consumption.^{[citation needed]}

Electronic cigarette

Electronic cigarettes is 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 solution. Many legislation and public health investigations are currently pending in many countries due to its relatively recent emergence.

Hookah

Hookah are a single or multi-stemmed (often glass-based) water pipe for smoking. Originally from India, 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.

Kreteks

Kreteks 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 kreteks can contain more than 30 types of tobacco. Minced dried clove buds weighing about 1/3 of the tobacco blend are added to add flavouring. Several states in the United States have baned Kreteks,^{[citation needed]} and in 2004 the United States prohibited cigarettes from having a "characterising flavor" of certain ingredients other than tobacco and menthol, thereby removing Kreteks from being classified as cigarettes.^[44]

Passive smoking

Passive smoking is the 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 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, 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 to make.

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.

Physiology

A graph that shows the efficiency of smoking as a way to absorb nicotine compared to other forms of intake.

The active substances in tobacco, especially cigarettes, is administered by burning the leaves and inhaling the vaporized 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 inefficient 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.^[9] 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), unionized nicotine is more readily absorbed through the mucous membranes in the mouth.^[45] Nicotine absorption from cigar and pipe, however, is much less than that from cigarette smoke.^[46]

The inhaled substances trigger chemical reactions in nerve endings. The cholinergic receptors are often triggered by the naturally occurring substance acetylcholine. Acetylcholine and Nicotine express chemical similarities, which allows Nicotine to tigger the receptor as well. These nicotinic acetylcholine receptors takes part in two major types of neurotransmission, synaptic transmission and paracrine signalling.^[47] This activity increases heart rate, memory, alertness,^[10] and produces a measurably faster reaction time after individuals have smoked.^[11] Dopamine and later endorphins are released, which are associated with sensations of pleasure and reward.^[12]

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 seems to play an important role in nicotine addiction—probably by facilitating a dopamine release in the nucleus accumbens as a response to nicotine stimuli.^[48]

Demographics

Percentage of females smoking any tobacco product

Percentage of males smoking any tobacco product. Note that there is a difference between the scales used for females and the scales used for males.^[39]

As of 2000, smoking is practiced by 1.22 billion people. Assuming no change in prevalence it is predicted that 1.45 billion people will smoke in 2010 and 1.5 to 1.9 billion in 2025. Assuming that prevalence will decrease at 1% a year and that there will be a modest increase of income of 2%, it is predicted the number of smokers will stand at 1.3 billion in 2010 and 2025.^[13]

Smoking is generally five times higher among men than women,^[13] however the gender gap declines with younger age.^[14][15] In developed countries smoking rates for men have peaked and have begun to decline, however for women they continue to climb.^[49]

As of 2002, about twenty percent of young teens (13–15) smoke worldwide. From which 80,000 to 100,000 children begin smoking every day—roughly half of which live in Asia. Half of those who begin smoking in adolescent years are projected to go on to smoke for 15 to 20 years.^[7]

The World Health Organization (WHO) states that "Much of the disease burden and premature mortality attributable to tobacco use disproportionately affect the poor". Of the 1.22 billion smokers, 1 billion of them live in developing or transitional economies. Rates of smoking have leveled off or declined in the developed world.^[50] In the developing world, however, tobacco consumption is rising by 3.4% per year as of 2002.^[7]

The WHO in 2004 projected 58.8 million deaths to occur globally,^[51] from which 5.4 million are tobacco-attributed,^[52] and 4.9 million as of 2007.^[53] As of 2002, 70% of the deaths are in developing countries.^[53]