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Methods__ For more about the production of the agricultural product, see Types of tobacco, Cultivation of tobacco, Curing of tobacco, and Tobacco 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.[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: 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 flakes for pipe smoking. Paan पान from Sanskrit Paantobacco in India and Nepal is also used in paan with a special kind of leaf mixed with kattha(brown liquid) and lime with tobacco. This practice has spread across Asia. Maawa & Gutka Maawa & gutka maawa & gutka are two other Indian products that are different in tastes and appearance. gutka is made with expired beatlenuts, expired tobacco, expired katha(brown liquids) etc. and mixed for a lot of days. maawa made on shops on demand with beatlenuts, different types of tobaccos and lime. 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.[43][44] Tendu Patta (Leaf) Collection for Beedi industries 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.[45] As of 2005 it is estimated that 4.3% of men and 0.3% of women smoke cigars in USA.[46] 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. Although rarely practiced, cigarettes can also be consumed rectally by inhaling the smoke into the mouth and pushing it through a pipe into the rectum.[47] French inhale The French inhale is the action performed by smokers of expelling smoke from the mouth and inhaling it into the nostrils.[48] 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.[49] 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" or "Roll-ups", are very popular particularly in European countries and the UK. These are prepared from loose tobacco, cigarette papers, and filters all bought separately. They are usually much cheaper than ready-made cigarettes and small contraptions can be bought making the process easier. 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. This method is often preferable when medically administrating the smoke substance, as opposed to directly pyrolyzing the plant material. Physiology__ See also: Chain smoking 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, 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.[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), non-ionised nicotine is more readily absorbed through the mucous membranes in the mouth.[50] Nicotine absorption from cigar and pipe, however, is much less than that from cigarette smoke.[51] 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.[52] 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,[10] and faster reaction times.[11] Nicotine acetylcholine stimulation is not directly addictive. However, since dopamine-releasing neurons are abundant on nicotine receptors, dopamine is released.[53] This release of dopamine, which is associated with pleasure, is reinforcing and may also increase working memory.[12][54] Nicotine and cocaine activate similar patterns of neurons, which supports the idea that common substrates among these drugs.[55] 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.[56] Using rat studies, withdrawal after repeated exposure to nicotine results in less responsive nucleus accumbens cells, which produce dopamine responsible for reinforcement.[57] Demographics__ Main article: Prevalence of tobacco consumption 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.[42] As of 2000, smoking was practised by around 1.22 billion people. At current rates of 'smoker replacement' and market growth, this may reach around 1.9 billion in 2025.[58] Smoking may be up to five times more prevalent amongst men than women in some communities,[58] although the gender gap usually declines with younger age.[14][15] In some developed countries smoking rates for men have peaked and begun to decline, while for women they continue to climb.[59] As of 2002, about twenty percent of young teenagers (13–15) smoked worldwide. From which 80,000 to 100,000 children begin smoking every day, roughly half of whom 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.[60] 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,[61] from which 5.4 million are tobacco-attributed,[62] and 4.9 million as of 2007.[63] As of 2002, 70% of the deaths are in developing countries.[63] |
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