Search This Blog

Wednesday, April 21, 2021

Tobacco smoking

From Wikipedia, the free encyclopedia
 
Marlboro's package of the ice blast cigarette

Tobacco smoking is the practice of burning tobacco and ingesting the tobacco smoke that is produced. The smoke may be inhaled, as is done with cigarettes, or simply released from the mouth, as is generally done with pipes and cigars. The practice is believed to have begun as early as 5000–3000 BC in Mesoamerica and South America. Tobacco was introduced to Eurasia in the late 17th century by European colonists, 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 Nazi Germany at the end of World War II. In 1950, British researchers demonstrated a clear relationship between smoking and cancer. 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 combusted. The resulting smoke is then inhaled and the active substances absorbed through the alveoli in the lungs or the oral mucosa. Many substances in cigarette smoke trigger chemical reactions in nerve endings, which heighten heart rate, alertness and reaction time, among other things. Dopamine and endorphins are released, which are often associated with pleasure. As of 2008 to 2010, tobacco is used by about 49% of men and 11% of women aged 15 or older in fourteen low-income and middle-income countries (Bangladesh, Brazil, China, Egypt, India, Mexico, Philippines, Poland, Russia, Thailand, Turkey, Ukraine, Uruguay and Vietnam), with about 80% of this usage in the form of smoking. 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 coughing. After an individual has smoked for some years, the avoidance of withdrawal symptoms and negative reinforcement become the key motivations to continue.

A 2009 study of first smoking experiences of seventh-grade students found out that the most common factor leading students to smoke is cigarette advertisements. Smoking by parents, siblings and friends also encourages students to smoke.

History

Use in ancient cultures

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

Smoking's history dates back to as early as 5000–3000 BC, when the agricultural product began to be cultivated in Mesoamerica and 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 civilizations – such as the Babylonians, the Indians, and the Chinese – burnt incense during religious rituals. 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. Also, to stimulate respiration, tobacco smoke enemas were used.

Eastern North American tribes would carry large amounts of tobacco in pouches as a readily accepted trade item and would often smoke it in ceremonial 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.

Popularization

Gentlemen Smoking and Playing Backgammon in an Interior by Dirck Hals, 1627

In 1612, six years after the settlement of Jamestown, Virginia, 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", revived 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. James VI and I, King of Scotland and England, produced the treatise A Counterblaste to Tobacco in 1604, and also introduced excise duty on the product. 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 morals and health. The Chongzhen Emperor of China issued an edict banning smoking two years before his death and the overthrow of the Ming dynasty. Later, the Manchu rulers of the Qing dynasty, 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.

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 flouted the ban to have their nostrils slit and their backs flayed. Pope Urban VIII likewise condemned smoking on holy places in a papal bull of 1624. Despite some concerted efforts, restrictions and bans were largely ignored. When James I of England, a staunch anti-smoker and the author of A Counterblaste to Tobacco, tried to curb the new trend by enforcing a 4000% tax increase on tobacco in 1604 it was unsuccessful, as suggested by the presence of around 7,000 tobacco outlets in London by the early 17th century. From this point on for some centuries, several administrations withdrew from efforts at discouragement and instead turned tobacco trade and cultivation into sometimes lucrative government monopolies.

By the mid-17th century most major civilizations had been introduced to tobacco smoking and in many cases had already assimilated it into the native culture, despite some continued attempts upon the parts of rulers to eliminate the practice with 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 appears to have entered currency in the late 18th century, before which less abbreviated descriptions of the practice such as drinking smoke were also in use.

Growth in the US remained stable until the American Civil War in 1860s, when the primary agricultural workforce shifted from slavery to sharecropping. This, along with a change in demand, accompanied the industrialization of cigarette production as craftsman James Bonsack created a machine in 1881 to partially automate their manufacture.

Social attitudes and public health

Jean-Jacques Susini with cigarette and glasses, 1972

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. In the 20th century, smoking was common. There were social events like the smoke night which promoted the habit.

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 (US cigarette consumption per person blue, male lung cancer rate green)

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 prospective study of some 40 thousand doctors for about 2.5 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.

Social campaigns have been instituted in many places to discourage smoking, such as Canada's National Non-Smoking Week.

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. 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.

As a result of public pressure and the FDA, Walmart and Sam's club announced that they were raising the minimum age to purchase tobacco products, including all e-cigarettes, to 21 starting 1 July 2019.

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 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.

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
Beedi
Beedis are thin South Asian cigarettes filled with tobacco flakes 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.
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 of 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 the 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.

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 honor 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 one-third 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.
Pipe smoking
Pipe smoking is done with a tobacco pipe, typically consisting 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.
Roll-your-own
Roll-your-own or hand-rolled cigarettes, often called "rollies", "cigi" 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

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 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 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-ionized 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. Nicotine and cocaine activate similar patterns of neurons, which supports the existence of common substrates among these drugs.

The absorbed nicotine mimics nicotinic acetylcholine which when bound to nicotinic acetylcholine receptors prevents the reuptake of acetylcholine thereby increasing that neurotransmitter in those areas of the body. These nicotinic acetylcholine receptors 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; and, in the nucleus accumbens, dopamine is associated with motivation causing reinforcing behavior. Dopamine increase, in the prefrontal cortex, may also increase working memory.

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 (an 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.

Demographics

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

As of 2000, smoking was practiced by around 1.22 billion people. At current rates of 'smoker replacement' and market growth, this may reach around 1.9 billion in 2025.

Smoking may be up to five times more prevalent among men than women in some communities, although the gender gap usually declines with younger age. In some developed countries smoking rates for men have peaked and begun to decline, while for women they continue to climb.

As of 2002, about twenty percent of young teenagers (13–15) smoked worldwide. 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. As of 2019 in the United States, roughly 800,000 high school students smoke.

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. In the developing world, however, tobacco consumption is rising by 3.4% per year as of 2002.

The WHO in 2004 projected 58.8 million deaths to occur globally, from which 5.4 million are tobacco-attributed, and 4.9 million as of 2007. As of 2002, 70% of the deaths are in developing countries. As of 2017, smoking causes one in ten deaths worldwide, with half of those deaths in the US, China, India and Russia.

Psychology

Takeup

Sigmund Freud, whose doctor assisted his suicide because of oral cancer caused by smoking

Most smokers begin smoking during adolescence or early adulthood. Some studies also show that smoking can also be linked to various mental health complications. Smoking has elements of risk-taking and rebellion, which often appeal to young people. The presence of peers that smoke and media featuring high-status models smoking may also encourage smoking. Because teenagers are influenced more by their peers than by adults, attempts by parents, schools, and health professionals at preventing people from trying cigarettes are often unsuccessful.

Children of smoking parents are more likely to smoke than children with non-smoking parents. Children of parents who smoke are less likely to quit smoking. One study found that parental smoking cessation was associated with less adolescent smoking, except when the other parent currently smoked. A current study tested the relation of adolescent smoking to rules regulating where adults are allowed to smoke in the home. Results showed that restrictive home smoking policies were associated with lower likelihood of trying smoking for both middle and high school students.

Behavioural research generally indicates that teenagers begin their smoking habits due to peer pressure, and cultural influence portrayed by friends. However, one study found that direct pressure to smoke cigarettes played a less significant part in adolescent smoking, with adolescents also reporting low levels of both normative and direct pressure to smoke cigarettes. Mere exposure to tobacco retailers may motivate smoking behaviour in adults. A similar study suggested that individuals may play a more active role in starting to smoke than has previously been thought and that social processes other than peer pressure also need to be taken into account. Another study's results indicated that peer pressure was significantly associated with smoking behavior across all age and gender cohorts, but that intrapersonal factors were significantly more important to the smoking behavior of 12- to 13-year-old girls than same-age boys. Within the 14- to 15-year-old age group, one peer pressure variable emerged as a significantly more important predictor of girls' than boys' smoking. It is debated whether peer pressure or self-selection is a greater cause of adolescent smoking.

Psychologist Hans Eysenck (who later was questioned for nonplausible results and unsafe publications)) developed a personality profile for the typical smoker. Extraversion is the trait that is most associated with smoking, and smokers tend to be sociable, impulsive, risk taking, and excitement seeking individuals.

Persistence

The reasons given by some smokers for this activity have been categorized as addictive smoking, pleasure from smoking, tension reduction/relaxation, social smoking, stimulation, habit/automatism, and handling. There are gender differences in how much each of these reasons contribute, with females more likely than males to cite tension reduction/relaxation, stimulation and social smoking.

Some smokers argue that the depressant effect of smoking allows them to calm their nerves, often allowing for increased concentration. However, according to the Imperial College London, "Nicotine seems to provide both a stimulant and a depressant effect, and it is likely that the effect it has at any time is determined by the mood of the user, the environment and the circumstances of use. Studies have suggested that low doses have a depressant effect, while higher doses have stimulant effect."

Patterns

A number of studies have established that cigarette sales and smoking follow distinct time-related patterns. For example, cigarette sales in the United States of America have been shown to follow a strongly seasonal pattern, with the high months being the months of summer, and the low months being the winter months.

Similarly, smoking has been shown to follow distinct circadian patterns during the waking day—with the high point usually occurring shortly after waking in the morning, and shortly before going to sleep at night.

Economic

In countries where there is a universally funded healthcare system, the government covers the cost of medical care for smokers who become ill through smoking in the form of increased taxes. Two broad debating positions exist on this front, the "pro-smoking" argument suggesting that heavy smokers generally do not live long enough to develop the costly and chronic illnesses which affect the elderly, reducing society's healthcare burden, and the "anti-smoking" argument suggests that the healthcare burden is increased because smokers get chronic illnesses younger and at a higher rate than the general population. Data on both positions has been contested. The Centers for Disease Control and Prevention published research in 2002 claiming that the cost of each pack of cigarettes sold in the United States was more than $7 in medical care and lost productivity. The cost may be higher, with another study putting it as high as $41 per pack, most of which however is on the individual and his/her family. This is how one author of that study puts it when he explains the very low cost for others: "The reason the number is low is that for private pensions, Social Security, and Medicare — the biggest factors in calculating costs to society — smoking actually saves money. Smokers die at a younger age and don't draw on the funds they've paid into those systems." Other research demonstrates that premature death caused by smoking may redistribute Social Security income in unexpected ways that affect behavior and reduce the economic well-being of smokers and their dependents. To further support this, whatever the rate of smoking consumption is per day, smokers have a greater lifetime medical cost on average compared to a non-smoker by an estimated $6000 Between the cost for lost productivity and health care expenditures combined, cigarette smoking costs at least 193 billion dollars (Research also shows that smokers earn less money than nonsmokers). As for secondhand smoke, the cost is over 10 billion dollars.

By contrast, some non-scientific studies, including one conducted by Philip Morris in the Czech Republic called Public Finance Balance of Smoking in the Czech Republic and another by the Cato Institute, support the opposite position. Philip Morris has explicitly apologised for the former study, saying: "The funding and public release of this study which, among other things, detailed purported cost savings to the Czech Republic due to premature deaths of smokers, exhibited terrible judgment as well as a complete and unacceptable disregard of basic human values. For one of our tobacco companies to commission this study was not just a terrible mistake, it was wrong. All of us at Philip Morris, no matter where we work, are extremely sorry for this. No one benefits from the very real, serious and significant diseases caused by smoking."

Between 1970 and 1995, per-capita cigarette consumption in poorer developing countries increased by 67 percent, while it dropped by 10 percent in the richer developed world. Eighty percent of smokers now live in less developed countries. By 2030, the World Health Organization (WHO) forecasts that 10 million people a year will die of smoking-related illness, making it the single biggest cause of death worldwide, with the largest increase to be among women. WHO forecasts the 21st century's death rate from smoking to be ten times the 20th century's rate ("Washingtonian" magazine, December 2007).

Health

Tobacco smoking is the leading cause of preventable death and a major public health concern.

There are 1.1 billion tobacco users in the world. One person dies every six seconds from a tobacco related disease.

head and torso of a male with internal organs shown and labels referring to the effects of tobacco smoking
Common adverse effects of tobacco smoking. The more common effects are in bold face.

Tobacco use leads most commonly to diseases affecting the heart and lungs, with smoking being a major risk factor for heart attacks, strokes, chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), emphysema, and cancer (particularly lung cancer, cancers of the larynx and mouth, esophageal cancer and pancreatic cancer). Cigarette smoking increases the risk of Crohn's disease as well as the severity of the course of the disease. It is also the number one cause of bladder cancer. The smoke from tobacco elicits carcinogenic effects on the tissues of the body that are exposed to the smoke.

Tobacco smoke is a complex mixture of over 7,000 toxic chemicals, several of which 98 are associated with an increased risk of cardiovascular disease and 69 of which are known to be carcinogenic. The most important chemicals causing cancer are those that produce DNA damage since such damage appears to be the primary underlying cause of cancer. Cunningham et al. combined the microgram weight of the compound in the smoke of one cigarette with the known genotoxic effect per microgram to identify the most carcinogenic compounds in cigarette smoke: acrolein, formaldehyde, acrylonitrile, 1,3-butadiene, acetaldehyde, ethylene oxide, and isoprene.

Cigarette smoking has also been associated with sarcopenia, the age-related loss of muscle mass and strength.

The World Health Organization estimates that tobacco caused 5.4 million deaths in 2004 and 100 million deaths over the course of the 20th century. Similarly, the United States Centers for Disease Control and Prevention describes tobacco use as "the single most important preventable risk to human health in developed countries and an important cause of premature death worldwide." Although 70% of smokers state their intention to quit only 3–5% are actually successful in doing so.

The probabilities of death from lung cancer before age 75 in the United Kingdom are 0.2% for men who never smoked (0.4% for women), 5.5% for male former smokers (2.6% in women), 15.9% for current male smokers (9.5% for women) and 24.4% for male "heavy smokers" defined as smoking more than 5 cigarettes per day (18.5% for women). Tobacco smoke can combine with other carcinogens present within the environment in order to produce elevated degrees of lung cancer.

The risk of lung cancer reduces almost from the first day someone quits smoking. Healthy cells that have escaped mutations grow and replace the damaged ones in the lungs. In the research dated December 2019, 40% of cells in former smokers looked like those of people who had never smoked.

Rates of smoking have generally leveled-off or declined in the developed world. Smoking rates in the United States have dropped by half from 1965 to 2006, falling from 42% to 20.8% in adults. In the developing world, tobacco consumption is rising by 3.4% per year.

Smoking alters the transcriptome of the lung parenchyma; the expression levels of a panel of seven genes (KMO, CD1A, SPINK5, TREM2, CYBB, DNASE2B, FGG) are increased in the lung tissue of smokers.

Passive smoking is the inhalation of tobacco smoke by individuals who are not actively smoking. Second-hand smoke (SHS) is the collection of chemicals released when the burning end is present, and environmental tobacco smoke (ETS) or third-hand smoke is the smoke that remains after the burning end has been extinguished. Because of its negative implications, exposure to SHS has played a central role in the regulation of tobacco products. Six hundred thousand deaths were attributed to SHS in 2004. It also has been known to produce skin conditions such as freckles and dryness.

In 2015, a meta-analysis found that smokers were at greater risk of developing psychotic illness. Tobacco has also been described an anaphrodisiac due to its propensity for causing erectile dysfunction.

Social

Famous smokers of the past used cigarettes or pipes as part of their image, such as Jean-Paul Sartre's Gauloises-brand cigarettes; Albert Einstein's, Douglas MacArthur's, Bertrand Russell's, and Bing Crosby's pipes; or the news broadcaster Edward R. Murrow's cigarette. Writers in particular seem to be known for smoking, for example, Cornell Professor Richard Klein's book Cigarettes are Sublime for the analysis, by this professor of French literature, of the role smoking plays in 19th and 20th century letters. The popular author Kurt Vonnegut addressed his addiction to cigarettes within his novels. British Prime Minister Harold Wilson was well known for smoking a pipe in public as was Winston Churchill for his cigars. Sherlock Holmes, the fictional detective created by Sir Arthur Conan Doyle, smoked a pipe, cigarettes, and cigars. The DC Vertigo comic book character John Constantine, created by Alan Moore, is synonymous with smoking, so much so that the first storyline by Preacher creator Garth Ennis centered around John Constantine contracting lung cancer. Professional wrestler James Fullington, while in character as "The Sandman", is a chronic smoker in order to appear "tough".

The problem of smoking at home is particularly difficult for women in many cultures (especially Arab cultures), where it may not be acceptable for a woman to ask her husband not to smoke at home or in the presence of her children. Studies have shown that pollution levels for smoking areas indoors are higher than levels found on busy roadways, in closed motor garages, and during fire storms. Furthermore, smoke can spread from one room to another, even if doors to the smoking area are closed.

The ceremonial smoking of tobacco, and praying with a sacred pipe, is a prominent part of the religious ceremonies of a number of Native American Nations. Sema, the Anishinaabe word for tobacco, is grown for ceremonial use and considered the ultimate sacred plant since its smoke is believed to carry prayers to the spirits. In most major religions, however, tobacco smoking is not specifically prohibited, although it may be discouraged as an immoral habit. Before the health risks of smoking were identified through controlled study, smoking was considered an immoral habit by certain Christian preachers and social reformers. The founder of the Latter Day Saint movement, Joseph Smith, recorded that on 27 February 1833, he received a revelation which discouraged tobacco use. This "Word of Wisdom" was later accepted as a commandment, and faithful Latter-day Saints abstain completely from tobacco. Jehovah's Witnesses base their stand against smoking on the Bible's command to "clean ourselves of every defilement of flesh" (2 Corinthians 7:1). The Jewish Rabbi Yisrael Meir Kagan (1838–1933) was one of the first Jewish authorities to speak out on smoking. In Ahmadiyya Islam, smoking is highly discouraged, although not forbidden. During the month of fasting however, it is forbidden to smoke tobacco. In the Baháʼí Faith, smoking tobacco is discouraged though not forbidden.

Incomes

One of the largest global enterprises in the world is known to be the tobacco industry. The six biggest tobacco companies made a combined profit of $35.1 billion (Jha et al., 2014) in 2010.

Public policy

On 27 February 2005 the WHO Framework Convention on Tobacco Control, took effect. The FCTC is the world's first public health treaty. Countries that sign on as parties agree to a set of common goals, minimum standards for tobacco control policy, and to cooperate in dealing with cross-border challenges such as cigarette smuggling. Currently the WHO declares that 4 billion people will be covered by the treaty, which includes 168 signatories. Among other steps, signatories are to put together legislation that will eliminate secondhand smoke in indoor workplaces, public transport, indoor public places and, as appropriate, other public places.

Taxation

Many governments have introduced excise taxes on cigarettes in order to reduce the consumption of cigarettes. The World Health Organisation finds that:

The structure of tobacco excise taxes varies considerably across countries, with lower income countries more likely to rely more on ad valorem excises and higher income countries more likely to rely more on specific excise taxes, while many countries at all income levels use a mix of specific and ad valorem excises.
Tobacco excise tax systems are quite complex in several countries, where different tax rates are applied based on prices, product characteristics such as presence/absence of a filter or length, packaging, weight, tobacco content, and/or production or sales volume. These complex systems are difficult to administer, create opportunities for tax avoidance, and are less effective from a public health perspective.
Globally, cigarette excise taxes account for less than 45 percent of cigarette prices, on average, while all taxes applied to cigarettes account for just over half of half of price. Higher income countries levy higher taxes on tobacco products and these taxes account for a greater share of price, with both the absolute tax and share of price accounted for by tax falling as country incomes fall.

In 2002, the Centers for Disease Control and Prevention said that each pack of cigarettes sold in the United States costs the nation more than $7 in medical care and lost productivity, around $3400 per year per smoker. Another study by a team of health economists finds the combined price paid by their families and society is about $41 per pack of cigarettes.

Substantial scientific evidence shows that higher cigarette prices result in lower overall cigarette consumption. Most studies indicate that a 10% increase in price will reduce overall cigarette consumption by 3% to 5%. Youth, minorities, and low-income smokers are two to three times more likely to quit or smoke less than other smokers in response to price increases. Smoking is often cited as an example of an inelastic good, however, i.e. a large rise in price will only result in a small decrease in consumption.

Many nations have implemented some form of tobacco taxation. As of 1997, Denmark had the highest cigarette tax burden of $4.02 per pack. Taiwan only had a tax burden of $0.62 per pack. The federal government of the United States charges $1.01 per pack.

Cigarette taxes vary widely from state to state in the United States. For example, Missouri has a cigarette tax of only 17 cents per pack, the nation's lowest, while New York has the highest cigarette tax in the U.S.: $4.35 per pack. In Alabama, Illinois, Missouri, New York City, Tennessee, and Virginia, counties and cities may impose an additional limited tax on the price of cigarettes. Sales taxes are also levied on tobacco products in most jurisdictions.

In the United Kingdom, a packet of 20 cigarettes has a tax added of 16.5% of the retail price plus £4.90. The UK has a significant black market for tobacco, and it has been estimated by the tobacco industry that 27% of cigarette and 68% of handrolling tobacco consumption is non-UK duty paid (NUKDP).

In Australia total taxes account for 62.5% of the final price of a packet of cigarettes (2011 figures). These taxes include federal excise or customs duty and Goods and Services Tax.

Restrictions

An enclosed smoking area in a Japanese train station. Notice the air vent on the roof.

In June 1967, the US Federal Communications Commission ruled that programmes broadcast on a television station which discussed smoking and health were insufficient to offset the effects of paid advertisements that were broadcast for five to ten minutes each day. In April 1970, the US Congress passed the Public Health Cigarette Smoking Act banning the advertising of cigarettes on television and radio starting on 2 January 1971.

The Tobacco Advertising Prohibition Act 1992 expressly prohibited almost all forms of Tobacco advertising in Australia, including the sponsorship of sporting or other cultural events by cigarette brands.

All tobacco advertising and sponsorship on television has been banned within the European Union since 1991 under the Television Without Frontiers Directive (1989). This ban was extended by the Tobacco Advertising Directive, which took effect in July 2005 to cover other forms of media such as the internet, print media, and radio. The directive does not include advertising in cinemas and on billboards or using merchandising – or tobacco sponsorship of cultural and sporting events which are purely local, with participants coming from only one Member State as these fall outside the jurisdiction of the European Commission. However, most member states have transposed the directive with national laws that are wider in scope than the directive and cover local advertising. A 2008 European Commission report concluded that the directive had been successfully transposed into national law in all EU member states, and that these laws were well implemented.

Some countries also impose legal requirements on the packaging of tobacco products. For example, in the countries of the European Union, Turkey, Australia and South Africa, cigarette packs must be prominently labeled with the health risks associated with smoking. Canada, Australia, Thailand, Iceland and Brazil have also imposed labels upon cigarette packs warning smokers of the effects, and they include graphic images of the potential health effects of smoking. Cards are also inserted into cigarette packs in Canada. There are sixteen of them, and only one comes in a pack. They explain different methods of quitting smoking. Also, in the United Kingdom, there have been a number of graphic NHS advertisements, one showing a cigarette filled with fatty deposits, as if the cigarette is symbolizing the artery of a smoker.

Some countries have also banned advertisement at point of sale. United Kingdom and Ireland have limited the advertisement of tobacco at retailers. This includes storing of cigarettes behind a covered shelf not visible to the public. They do however allow some limited advertising at retailers. Norway has a complete ban of point of sale advertising. This includes smoking products and accessories. Implementing these policies can be challenging, all of these countries experienced resistance and challenges from the tobacco industry. The World Health Organisation recommends the complete ban of all types of advertisement or product placement, including at vending machines, at airports and on internet shops selling tobacco. The evidence is as yet unclear as to the impact of such bans.  

Many countries have a smoking age. In many countries, including the United States, most European Union member states, New Zealand, Canada, South Africa, Israel, India, Brazil, Chile, Costa Rica and Australia, it is illegal to sell tobacco products to minors and in the Netherlands, Austria, Belgium, Denmark and South Africa it is illegal to sell tobacco products to people under the age of 16. On 1 September 2007 the minimum age to buy tobacco products in Germany rose from 16 to 18, as well as in the United Kingdom where on 1 October 2007 it rose from 16 to 18. Underlying such laws is the belief that people should make an informed decision regarding the risks of tobacco use. These laws have a lax enforcement in some nations and states. In China, Turkey, and many other countries usually a child will have little problem buying tobacco products, because they are often told to go to the store to buy tobacco for their parents.

Several countries such as Ireland, Latvia, Estonia, the Netherlands, Finland, Norway, Canada, Australia, Sweden, Portugal, Singapore, Italy, Indonesia, India, Lithuania, Chile, Spain, Iceland, United Kingdom, Slovenia, Turkey and Malta have legislated against smoking in public places, often including bars and restaurants. Restaurateurs have been permitted in some jurisdictions to build designated smoking areas (or to prohibit smoking). In the United States, many states prohibit smoking in restaurants, and some also prohibit smoking in bars. In provinces of Canada, smoking is illegal in indoor workplaces and public places, including bars and restaurants. As of 31 March 2008 Canada has introduced a smoke-free law ban in all public places, as well as within 10 metres of an entrance to any public place. In Australia, smoke-free laws vary from state to state. Currently, Queensland has completely smoke-free indoor public places (including workplaces, bars, pubs and eateries) as well as patrolled beaches and some outdoor public areas. There are, however, exceptions for designated smoking areas. In Victoria, smoking is restricted in railway stations, bus stops and tram stops as these are public locations where second-hand smoke can affect non-smokers waiting for public transport, and since 1 July 2007 is now extended to all indoor public places. In New Zealand and Brazil, smoking is restricted in enclosed public places including bars, restaurants and pubs. Hong Kong restricted smoking on 1 January 2007 in the workplace, public spaces such as restaurants, karaoke rooms, buildings, and public parks (bars which do not admit minors were exempt until 2009). In Romania smoking is illegal in trains, metro stations, public institutions (except where designated, usually outside) and public transport. In Germany, additionally to smoking bans in public buildings and transports, an anti-smoking ordinance for bars and restaurants was implemented in late 2007. A study by the University of Hamburg (Ahlfeldt and Maennig 2010) demonstrates, that the smoking ban had, if any, only short run impacts on bar and restaurant revenues. In the medium and long run no negative effect was measurable. The results suggest either, that the consumption in bars and restaurants is not affected by smoking bans in the long run, or, that negative revenue impacts by smokers are compensated by increasing revenues through non-smokers.

Ignition safety

An indirect public health problem posed by cigarettes is that of accidental fires, usually linked with consumption of alcohol. Enhanced combustion using nitrates was traditionally used but cigarette manufacturers have been silent on this subject claiming at first that a safe cigarette was technically impossible, then that it could only be achieved by modifying the paper. Roll your own cigarettes contain no additives and are fire safe. Numerous fire safe cigarette designs have been proposed, some by tobacco companies themselves, which would extinguish a cigarette left unattended for more than a minute or two, thereby reducing the risk of fire. Among American tobacco companies, some have resisted this idea, while others have embraced it. RJ Reynolds was a leader in making prototypes of these cigarettes in 1983 and will make all of their U.S. market cigarettes to be fire-safe by 2010. Phillip Morris is not in active support of it. Lorillard (purchased by RJ Reynolds), the US' 3rd-largest tobacco company, seems to be ambivalent.

Gateway drug theory

The relationship between tobacco and other drug use has been well-established, however the nature of this association remains unclear. The two main theories are the phenotypic causation (gateway) model and the correlated liabilities model. The causation model argues that smoking is a primary influence on future drug use, while the correlated liabilities model argues that smoking and other drug use are predicated on genetic or environmental factors. One study published by the NIH found that tobacco use may be linked to cocaine addiction and marijuana use. The study stated that 90% of adults who used cocaine had smoked cigarettes before (this was for people ages 18–34). This study could support the gateway drug theory.

Cessation

Smoking cessation, referred to as "quitting", is the action leading towards abstinence of tobacco smoking. Methods of "quitting" include advice from physicians or social workers, cold turkey, nicotine replacement therapy, contingent vouchers, antidepressants, hypnosis, self-help (mindfulness meditation), and support groups. A meta-analysis from 2018, conducted on 61 RCT, showed that one year after people quit smoking with the assistance of first‐line smoking cessation medications (and some behavioral help), only a little under 20% of smokers remained sustained abstinence.


Sustainable agriculture

From Wikipedia, the free encyclopedia

Sustainable agriculture is farming in sustainable ways meeting society's present food and textile needs, without compromising the ability for current or future generations to meet their needs. It can be based on an understanding of ecosystem services. There are many methods to increase the sustainability of agriculture. When developing agriculture within sustainable food systems, it is important to develop flexible business process and farming practices.

Agriculture has an enormous environmental footprint, playing a significant role in causing climate change, water scarcity, land degradation, deforestation and other processes; it is simultaneously causing environmental changes and being impacted by these changes. Developing sustainable food systems, contributes to the sustainability of the human population. For example, one of the best ways to mitigate climate change is to create sustainable food systems based on sustainable agriculture. Sustainable agriculture provides a potential solution to enable agricultural systems to feed a growing population within the changing environmental conditions.

History

In 1907, the American author Franklin H. King discussed in his book Farmers of Forty Centuries the advantages of sustainable agriculture and warned that such practices would be vital to farming in the future. The phrase 'sustainable agriculture' was reportedly coined by the Australian agronomist Gordon McClymont. The term became popular in the late 1980s.

There was an international symposium on sustainability in horticulture by the International Society of Horticultural Science at the International Horticultural Congress in Toronto in 2002. At the following conference at Seoul in 2006, the principles were discussed further.

Definition

In the US National Agricultural Research, Extension, and Teaching Policy Act of 1977, the term "sustainable agriculture" is defined as an integrated system of plant and animal production practices having a site-specific application that will, over the long term:

  • satisfy human food and fiber needs
  • enhance environmental quality and the natural resource base upon which the agriculture economy depends
  • make the most efficient use of nonrenewable resources and on-farm resources and integrate, where appropriate, natural biological cycles and controls
  • sustain the economic viability of farm operations
  • enhance the quality of life for farmers and society as a whole.

The British scholar Jules Pretty has stated several key principles associated with sustainability in agriculture:

  1. The incorporation of biological and ecological processes such as nutrient cycling, soil regeneration, and nitrogen fixation into agricultural and food production practices.
  2. Using decreased amounts of non-renewable and unsustainable inputs, particularly environmentally harmful ones.
  3. Using the expertise of farmers to both productively work the land as well as to promote the self-reliance and self-sufficiency of farmers.
  4. Solving agricultural and natural resource problems through the cooperation and collaboration of people with different skills. The problems tackled include pest management and irrigation.

It “considers long-term as well as short-term economics because sustainability is readily defined as forever, that is, agricultural environments that are designed to promote endless regeneration”. It balances the need for resource conservation with the needs of farmers pursuing their livelihood.

It is considered to be reconciliation ecology, accommodating biodiversity within human landscapes.

Different viewpoints

There is a debate on the definition of sustainability regarding agriculture. The definition could be characterized by two different approaches: an ecocentric approach and a technocentric approach. The ecocentric approach emphasizes no- or low-growth levels of human development, and focuses on organic and biodynamic farming techniques with the goal of changing consumption patterns, and resource allocation and usage. The technocentric approach argues that sustainability can be attained through a variety of strategies, from the view that state-led modification of the industrial system like conservation-oriented farming systems should be implemented, to the argument that biotechnology is the best way to meet the increasing demand for food.

One can look at the topic of sustainable agriculture through two different lenses: multifunctional agriculture and ecosystem services. Both of approaches are similar, but look at the function of agriculture differently. Those that employ the multifunctional agriculture philosophy focus on farm-centered approaches, and define function as being the outputs of agricultural activity. The central argument of multifunctionality is that agriculture is a multifunctional enterprise with other functions aside from the production of food and fiber. These functions include renewable resource management, landscape conservation and biodiversity. The ecosystem service-centered approach posits that individuals and society as a whole receive benefits from ecosystems, which are called "ecosystem services". In sustainable agriculture, the services that ecosystems provide include pollination, soil formation, and nutrient cycling, all of which are necessary functions for the production of food.

It is also claimed sustainable agriculture is best considered as an ecosystem approach to agriculture, called agroecology.

Ethics

Most agricultural professionals agree that there is a "moral obligation to pursue [the] goal [of] sustainability." The major debate comes from what system will provide a path to that goal because if an unsustainable method is used on a large scale it will have a massive negative effect on the environment and human population.

Factors affecting sustainability

Traditional farming methods have a low carbon footprint.

Practices that can cause long-term damage to soil include excessive tilling of the soil (leading to erosion) and irrigation without adequate drainage (leading to salinization).

Conservation farming in Zambia

The most important factors for a farming site are climate, soil, nutrients and water resources. Of the four, water and soil conservation are the most amenable to human intervention. When farmers grow and harvest crops, they remove some nutrients from the soil. Without replenishment, the land suffers from nutrient depletion and becomes either unusable or suffers from reduced yields. Sustainable agriculture depends on replenishing the soil while minimizing the use or need of non-renewable resources, such as natural gas or mineral ores.

A farm that can "produce perpetually", yet has negative effects on environmental quality elsewhere is not sustainable agriculture. An example of a case in which a global view may be warranted is the application of fertilizer or manure, which can improve the productivity of a farm but can pollute nearby rivers and coastal waters (eutrophication). The other extreme can also be undesirable, as the problem of low crop yields due to exhaustion of nutrients in the soil has been related to rainforest destruction. In Asia, the specific amount of land needed for sustainable farming is about 12.5 acres which include land for animal fodder, cereal production as a cash crop, and other food crops. In some cases, a small unit of aquaculture is included (AARI-1996).

Nutrients

Nitrates

Possible sources of nitrates that would, in principle, be available indefinitely, include:

  1. recycling crop waste and livestock or treated human manure
  2. growing legume crops and forages such as peanuts or alfalfa that form symbioses with nitrogen-fixing bacteria called rhizobia
  3. industrial production of nitrogen by the Haber process uses hydrogen, which is currently derived from natural gas (but this hydrogen could instead be made by electrolysis of water using renewable electricity)
  4. genetically engineering (non-legume) crops to form nitrogen-fixing symbioses or fix nitrogen without microbial symbionts.

The last option was proposed in the 1970s, but is only gradually becoming feasible. Sustainable options for replacing other nutrient inputs such as phosphorus and potassium are more limited.

Other options include long-term crop rotations, returning to natural cycles that annually flood cultivated lands (returning lost nutrients) such as the flooding of the Nile, the long-term use of biochar, and use of crop and livestock landraces that are adapted to less than ideal conditions such as pests, drought, or lack of nutrients. Crops that require high levels of soil nutrients can be cultivated in a more sustainable manner with appropriate fertilizer management practices.

Phosphate

Phosphate is a primary component in fertilizer. It is the second most important nutrient for plants after nitrogen, and is often a limiting factor. It is important for sustainable agriculture as it can improve soil fertility and crop yields. Phosphorus is involved in all major metabolic processes including photosynthesis, energy transfer, signal transduction, macromolecular biosynthesis, and respiration. It is needed for root ramification and strength and seed formation, and can increase disease resistance.

Phosphorus is found in the soil in both inorganic and organic forms and makes up approximately 0.05% of soil biomass. Phosphorus fertilizers are the main input of inorganic phosphorus in agricultural soils and approximately 70%–80% of phosphorus in cultivated soils is inorganic. Long-term use of phosphate-containing chemical fertilizers causes eutrophication and deplete soil microbial life, so people have looked to other sources.

Phosphorus fertilizers are manufactured from rock phosphate. However, rock phosphate is a non-renewable resource and it is being depleted by mining for agricultural use: peak phosphorus will occur within the next few hundred years, or perhaps earlier.

Potassium

Potassium is a macronutrient very important for plant development and is commonly sought in fertilizers. This nutrient is essential for agriculture because it improves water retention, nutrient value, yield, taste, color, texture and disease resistance of crops. It is often used in the cultivation of fruit and vegetables, rice, wheat and other grains, sugar, corn, soybeans, palm oil and coffee.

Potassium chloride (KCl) represents the most widely source of K used in agriculture, accounting for 90% of all potassium produced for agricultural use.  

The use of KCl leads to high concentrations of chloride (Clˉ) in soil harming its health due to the increase in soil salinity, imbalance in nutrient availability and this ion’s biocidal effect for soil organisms. In consequences the development of plants and soil organisms is affected, putting at risk soil biodiversity and agricultural productivity. A sustainable option for replacing KCl are chloride-free fertilizers, its use should take into account plants’ nutrition needs, and the promotion of soil health.

Soil

Walls built to avoid water run-off. Andhra Pradesh, India

Land degradation is becoming a severe global problem. According to the Intergovernmental Panel on Climate Change: "About a quarter of the Earth's ice-free land area is subject to human-induced degradation (medium confidence). Soil erosion from agricultural fields is estimated to be currently 10 to 20 times (no tillage) to more than 100 times (conventional tillage) higher than the soil formation rate (medium confidence)." Over a billion tonnes of southern Africa's soil are being lost to erosion annually, which if continued will result in halving of crop yields within thirty to fifty years. Improper soil management is threatening the ability to grow sufficient food. Intensive agriculture reduces the carbon level in soil, impairing soil structure, crop growth and ecosystem functioning, and accelerating climate change.

Soil management techniques include no-till farming, keyline design and windbreaks to reduce wind erosion, reincorporation of organic matter into the soil, reducing soil salinization, and preventing water run-off.

Land

As the global population increases and demand for food increases, there is pressure on land as a resource. In land-use planning and management, considering the impacts of land-use changes on factors such as soil erosion can support long-term agricultural sustainability, as shown by a study of Wadi Ziqlab, a dry area in the Middle East where farmers graze livestock and grow olives, vegetables, and grains.

Looking back over the 20th century shows that for people in poverty, following environmentally sound land practices has not always been a viable option due to many complex and challenging life circumstances. Currently, increased land degradation in developing countries may be connected with rural poverty among smallholder farmers when forced into unsustainable agricultural practices out of necessity.

Converting big parts of the land surface to agriculture have severe environmental and health consequences. For example, it leads to rise in Zoonotic disease like the Coronavirus disease 2019, by degrading natural buffers between humans and animals, reducing biodiversity and creating big groups of genetically similar animals.

Land is a finite resource on Earth. Although expansion of agricultural land can decrease biodiversity and contribute to deforestation, the picture is complex; for instance, a study examining the introduction of sheep by Norse settlers (Vikings) to the Faroe Islands of the North Atlantic concluded that, over time, the fine partitioning of land plots contributed more to soil erosion and degradation than grazing itself.

The Food and Agriculture Organization of the United Nations estimates that in coming decades, cropland will continue to be lost to industrial and urban development, along with reclamation of wetlands, and conversion of forest to cultivation, resulting in the loss of biodiversity and increased soil erosion.

Energy

In modern agriculture, energy is used in on-farm mechanisation, food processing, storage, and transportation processes. It has therefore been found that energy prices are closely linked to food prices. Oil is also used as an input in agricultural chemicals. The International Energy Agency projects higher prices of non-renewable energy resources as a result of fossil fuel resources being depleted. It may therefore decrease global food security unless action is taken to 'decouple' fossil fuel energy from food production, with a move towards 'energy-smart' agricultural systems including renewable energy. The use of solar powered irrigation in Pakistan is said to be a closed system for agricultural water irrigation.

The environmental cost of transportation could be avoided if people use local products.

Water

In some areas sufficient rainfall is available for crop growth, but many other areas require irrigation. For irrigation systems to be sustainable, they require proper management (to avoid salinization) and must not use more water from their source than is naturally replenishable. Otherwise, the water source effectively becomes a non-renewable resource. Improvements in water well drilling technology and submersible pumps, combined with the development of drip irrigation and low-pressure pivots, have made it possible to regularly achieve high crop yields in areas where reliance on rainfall alone had previously made successful agriculture unpredictable. However, this progress has come at a price. In many areas, such as the Ogallala Aquifer, the water is being used faster than it can be replenished.

According to the UC Davis Agricultural Sustainability Institute, several steps must be taken to develop drought-resistant farming systems even in "normal" years with average rainfall. These measures include both policy and management actions:

  1. improving water conservation and storage measures
  2. providing incentives for selection of drought-tolerant crop species
  3. using reduced-volume irrigation systems
  4. managing crops to reduce water loss
  5. not planting crops at all.

Indicators for sustainable water resource development include the average annual flow of rivers from rainfall, flows from outside a country, the percentage of water coming from outside a country, and gross water withdrawal.

Economics

Costs, such as environmental problems, not covered in traditional accounting systems (which take into account only the direct costs of production incurred by the farmer) are known as externalities.

Netting studied sustainability and intensive agriculture in smallholder systems through history.

There are several studies incorporating externalities such as ecosystem services, biodiversity, land degradation, and sustainable land management in economic analysis. These include The Economics of Ecosystems and Biodiversity study and the Economics of Land Degradation Initiative which seek to establish an economic cost-benefit analysis on the practice of sustainable land management and sustainable agriculture.

Triple bottom line frameworks include social and environmental alongside a financial bottom line. A sustainable future can be feasible if growth in material consumption and population is slowed down and if there is a drastic increase in the efficiency of material and energy use. To make that transition, long- and short-term goals will need to be balanced enhancing equity and quality of life.

Methods

Countries' evaluation of trends in the use of selected management practices and approaches

Other practices include growing a diverse number of perennial crops in a single field, each of which would grow in separate season so as not to compete with each other for natural resources. This system would result in increased resistance to diseases and decreased effects of erosion and loss of nutrients in soil. Nitrogen fixation from legumes, for example, used in conjunction with plants that rely on nitrate from soil for growth, helps to allow the land to be reused annually. Legumes will grow for a season and replenish the soil with ammonium and nitrate, and the next season other plants can be seeded and grown in the field in preparation for harvest.

Sustainable methods of weed management may help reduce the development of herbicide-resistant weeds. Crop rotation may also replenish nitrogen if legumes are used in the rotations and may also use resources more efficiently.

Rotational grazing with pasture divided into paddocks

There are also many ways to practice sustainable animal husbandry. Some of the tools to grazing management include fencing off the grazing area into smaller areas called paddocks, lowering stock density, and moving the stock between paddocks frequently.

Intensification

An increased production is a goal of intensification. Sustainable intensification encompasses specific agriculture methods that increase production and at the same time help improve environmental outcomes. The desired outcomes of the farm are achieved without the need for more land cultivation or destruction of natural habitat; the system performance is upgraded with no net environmental cost. Sustainable Intensification has become a priority for the United Nations. Sustainable intensification differs from prior intensification methods by specifically placing importance on broader environmental outcomes. By the year 2018; it was predicted in 100 nations a combined total of 163 million farms used sustainable intensification. The amount of agricultural land covered by this is 453 million ha of land. That amount of land is equal to 29% of farms worldwide. In light of concerns about food security, human population growth and dwindling land suitable for agriculture, sustainable intensive farming practises are needed to maintain high crop yields, while maintaining soil health and ecosystem services. The capacity for ecosystem services to be strong enough to allow a reduction in use of non-renewable inputs whilst maintaining or boosting yields has been the subject of much debate. Recent work in irrigated rice production system of east Asia has suggested that - in relation to pest management at least - promoting the ecosystem service of biological control using nectar plants can reduce the need for insecticides by 70% whilst delivering a 5% yield advantage compared with standard practice.

Vertical farming is a concept with the potential advantages of year-round production, isolation from pests and diseases, controllable resource recycling and reduced transportation costs.

Water

Water efficiency can be improved by reducing the need for irrigation and using alternative methods. Such methods includes: researching on drought resistant crops, monitoring plant transpiration and reducing soil evaporation.

Drought resistant crops have been researched extensively as a means to overcome the issue of water shortage. They are modified genetically so they can adapt in an environment with little water. This is beneficial as it reduces the need for irrigation and helps conserve water. Although they have been extensively researched, significant results have not been achieved as most of the successful species will have no overall impact on water conservation. However, some grains like rice, for example, have been successfully genetically modified to be drought resistant.

Soil and nutrients

Soil amendments include using compost from recycling centers. Using compost from yard and kitchen waste uses available resources in the area.

Abstinence from soil tillage before planting and leaving the plant residue after harvesting reduces soil water evaporation; It also serves to prevent soil erosion.

Crop residues left covering the surface of the soil may result in reduced evaporation of water, a lower surface soil temperature, and reduction of wind effects.

A way to make rock phosphate more effective is to add microbial inoculates such as phosphate-solubilizing microorganisms, known as PSMs, to the soil. These solubilize phosphorus already in the soil and use processes like organic acid production and ion exchange reactions to make that phosphorus available for plants. Experimentally, these PSMs have been shown to increase crop growth in terms of shoot height, dry biomass and grain yield.

Phosphorus uptake is even more efficient with the presence of mycorrhizae in the soil. Mycorrhiza is a type of mutualistic symbiotic association between plants and fungi, which are well-equipped to absorb nutrients, including phosphorus, in soil. These fungi can increase nutrient uptake in soil where phosphorus has been fixed by aluminum, calcium, and iron. Mycorrhizae can also release organic acids that solubilize otherwise unavailable phosphorus.

Pests and weeds

Sheet steaming with a MSD/moeschle steam boiler (left side)

Soil steaming can be used as an alternative to chemicals for soil sterilization. Different methods are available to induce steam into the soil to kill pests and increase soil health.

Solarizing is based on the same principle, used to increase the temperature of the soil to kill pathogens and pests.

Certain plants can be cropped for use as biofumigants, "natural" fumigants, releasing pest suppressing compounds when crushed, ploughed into the soil, and covered in plastic for four weeks. Plants in the Brassicaceae family release large amounts of toxic compounds such as methyl isothiocyanates.

Plants

Sustainability may also involve crop rotation. Crop rotation and cover crops prevent soil erosion, by protecting topsoil from wind and water. Effective crop rotation can reduce pest pressure on crops and replenish soil nutrients. This reduces the need for fertilizers and pesticides. Increasing the diversity of crops by introducing new genetic resources can increase yields. Perennial crops reduce the need for tillage and thus help mitigate soil erosion, and may sometimes tolerate drought better, increase water quality and help increase soil organic matter. There are research programs attempting to develop perennial substitutes for existing annual crops, such as replacing wheat with the wild grass Thinopyrum intermedium, or possible experimental hybrids of it and wheat.

Traditional agriculture

Sustainability, external inputs needed, and labour requirements of selected plant disease management practices of traditional farmers.

Often thought of as inherently destructive, slash-and-burn or slash-and-char shifting cultivation have been practised in the Amazon for thousands of years.

Some traditional systems combine polyculture with sustainability. In South-East Asia, rice-fish systems on rice paddies have raised freshwater fish as well as rice, producing an additional product and reducing eutrophication of neighbouring rivers. A variant in Indonesia combines rice, fish, ducks and water fern; the ducks eat the weeds that would otherwise limit rice growth, saving labour and herbicides, while the duck and fish manure substitute for fertilizer.

Raised field agriculture has been recently revived in certain areas of the world, such as the Altiplano region in Bolivia and Peru. This has resurged in the form of traditional Waru Waru raised fields, which create nutrient-rich soil in regions where such soil is scarce. This method is extremely productive and has recently been utilized by indigenous groups in the area and the nearby Amazon Basin to make use of lands that have been historically hard to cultivate.

In Ohio, some farmers that could not buy land good for agriculture restored soil considered as unsuitable for any agricultural activity with traditional methods.

Indigenous Agriculture

Native Americans in the United States practiced sustainable agriculture through their subsistence farming techniques. Many tribes grew or harvested their own food from plants that thrived in their local ecosystems. Native American farming practices are specific to local environments and work with natural processes. This is a practice called Permaculture, and it involves a deep understanding of the local environment. Native American farming techniques also incorporate local biodiversity into many of their practices, which helps the land remain healthy.

Many indigenous tribes incorporated Intercropping into their agriculture, which is a practice where multiple crops are planted together in the same area. This strategy allows crops to help one another grow through exchanged nutrients, maintained soil moisture, and physical supports for one another. The crops that are paired in intercropping often do not heavily compete for resources, which helps them to each be successful. Intercropping also provides a natural strategy for pest management and the prevention of weed growth. Intercropping is a natural agricultural practice that often improves the overall health of the soil and plants, increases crop yield, and is sustainable.

One of the most significant aspects of indigenous sustainable agriculture is their traditional ecological knowledge of harvesting. The Anishinaabe tribes follow an ideology known as “the Honorable Harvest.” The Honorable Harvest is a set of practices that emphasize the idea that people should “take only what you need and use everything you take.” Resources are conserved through this practice because several rules are followed when harvesting a plant. These rules are to never take the first plant, never take more than half of the plants, and never take the last plant. This encourages future growth of the plant and therefore leads to a sustainable use of the plants in the area.

Native Americans practiced agroforestry by managing the forest, animals, and crops together. They also helped promote tree growth through controlled burns and Silviculture. Often, the remaining ash from these burns would be used to fertilize their crops. By improving the conditions of the forest, the local wildlife populations also increased. Native Americans allowed their livestock to graze in the forest, which provided natural fertilizer for the trees as well.

Alternative agriculture

Shade-grown coffee, a form of polyculture in imitation of natural ecosystems. Trees provide resources for the coffee plants such as shade, nutrients, and soil structure; the farmers harvest coffee and timber.

The use of available city space (e.g., rooftop gardens, community gardens, garden sharing, and other forms of urban agriculture) may be able to contribute to sustainability.

There is limited evidence polyculture may contribute to sustainable agriculture. A meta-analysis of a number of polycrop studies found that predator insect biodiversity was higher at comparable yields than conventional in certain two-crop systems with a single cash crop combined with a cover crop.

One approach to sustainability is to develop polyculture systems using perennial crop varieties. Such varieties are being developed for rice, wheat, sorghum, barley, and sunflowers. If these can be combined in polyculture with a leguminous cover crop such as alfalfa, fixation of nitrogen will be added to the system, reducing the need for fertilizer and pesticides.

Organic Agriculture

Organic agriculture can be defined as:

an integrated farming system that strives for sustainability, the enhancement of soil fertility and biological diversity whilst, with rare exceptions, prohibiting synthetic pesticides, antibiotics, synthetic fertilizers, genetically modified organisms, and growth hormones.

Some claim organic agriculture may produce the most sustainable products available for consumers in the US, where no other alternatives exist, although the focus of the organics industry is not sustainability.

In 2018 the sales of organic products in USA reach $52.5 billion According to a big survey two thirds of Americans consume organic products at least occasionally

Regenerative Agriculture

Regenerative agriculture is a conservation and rehabilitation approach to food and farming systems. It focuses on topsoil regeneration, increasing biodiversity, improving the water cycle, enhancing ecosystem services, supporting biosequestration, increasing resilience to climate change, and strengthening the health and vitality of farm soil. Practices include, recycling as much farm waste as possible, and adding composted material from sources outside the farm.

Permaculture

Permaculture is an approach to land management and philosophy that adopts arrangements observed in flourishing natural ecosystems. It includes a set of design principles derived using whole systems thinking. It uses these principles in fields such as regenerative agriculture, rewilding, and community resilience. Permaculture was originally a portmanteau of "permanent agriculture", but was later adjusted to "permanent culture", to incorporate necessary social aspects as inspired by Masanobu Fukuoka's natural farming. The term was coined by Bill Mollison and David Holmgren in 1978, who formulated the concept in opposition to Western industrialized methods and in congruence with Indigenous or traditional knowledge.

Permaculture has many branches including ecological design, ecological engineering, regenerative design, environmental design, and construction. It also includes integrated water resources management that develops sustainable architecture, and regenerative and self-maintained habitat and agricultural systems modeled from natural ecosystems. Permaculture has been implemented and gained widespread visibility throughout the world as an agricultural and architectural design system and as a guiding life principle or philosophy. Much of its success has been attributed to the role of Indigenous knowledge and traditions, which the practice itself is rooted in. In turn, the rise of permaculture has revalidated Indigenous knowledge in circles where it was previously devalued.

Sustainability Standards

Numerous sustainability standards and certification systems exist, including organic certification, Rainforest Alliance, Fair Trade, UTZ Certified, GlobalGAP, Bird Friendly, and the Common Code for the Coffee Community (4C). These standards specify rules that producers , manufacturers and traders need to follow so that the things they make, grow or do don’t hurt people and the environment. These standards are also known as Voluntary Sustainability Standards (VSS) that are private standards that require products to meet specific economic, social or environmental sustainability metrics. The requirements can refer to product quality or attributes, but also to production and processing methods, as well as transportation. VSS are mostly designed and marketed by non-governmental organizations (NGOs) or private firms and they are adopted by actors up and down the value chain, from farmers to retailers. Certifications and labels are used to signal the successful implementation of a VSS. According to the ITC standards map the mostly covered products by standards are agricultural products. Around 500 VSS today apply to key exports of many developing countries, such as coffee, tea, bananas, cocoa, palm oil, timber, cotton, and organic agri-foods. VSS are found to reduce eutrophication, water use, greenhouse gas emissions, and natural ecosystem conversion. And thus are considered as a potential tool for sustainable agriculture.

According to the ITC Standards Map, the mostly covered sector by sustainability standards is the agricultural sector.

Social factors

Rural economic development

In 2007, the United Nations reported on "Organic Agriculture and Food Security in Africa", stating that using sustainable agriculture could be a tool in reaching global food security without expanding land usage and reducing environmental impacts. There has been evidence provided by developing nations from the early 2000s stating that when people in their communities are not factored into the agricultural process that serious harm is done. The social scientist Charles Kellogg has stated that, "In a final effort, exploited people pass their suffering to the land." Sustainable agriculture mean the ability to permanently and continuously "feed its constituent populations."

There are a lot of opportunities that can increase farmers’ profits, improve communities, and continue sustainable practices. For example, in Uganda Genetically Modified Organisms were originally illegal, however, with the stress of banana crisis in Uganda where Banana Bacterial Wilt had the potential to wipe out 90% of yield they decided to explore GMOs as a possible solution. The government issued the National Biotechnology and Biosafety bill which will allow scientists that are part of the National Banana Research Program to start experimenting with genetically modified organisms. This effort has the potential to help local communities because a significant portion live off the food they grow themselves and it will be profitable because the yield of their main produce will remain stable.

Not all regions are suitable for agriculture. The technological advancement of the past few decades has allowed agriculture to develop in some of these regions. For example, Nepal has built greenhouses to deal with its high altitude and mountainous regions. Greenhouses allow for greater crop production and also use less water since they are closed systems.

Desalination techniques can turn salt water into fresh water which allows greater access to water for areas with a limited supply. This allows the irrigation of crops without decreasing natural fresh water sources. While desalination can be a tool to provide water to areas that need it to sustain agriculture, it requires money and resources. Regions of China have been considering large scale desalination in order to increase access to water, but the current cost of the desalination process makes it impractical.

Women

Selling produce at an American farmers market

Women working in sustainable agriculture come from numerous backgrounds, ranging from academia to labour. From 1978-2007, in the United States, the number of women farm operators has tripled. In 2007, women operated 14 percent of farms, compared to five percent in 1978. Much of the growth is due to women farming outside of the "male dominated field of conventional agriculture".

Growing your own food

The practice of growing food in the backyard of houses, schools, etc., by families or by communities became widespread in the US at the time of world war one, the great recession and world war two, so that in one point of time 40% of the vegetables of the USA was produced in this way. The practice became more popular again in the time of the COVID-19 pandemic. This method permits to grow food in a relatively sustainable way and at the same time make easier for poor people to obtain food.

Policy

Delaware Valley University's "Roth Center for Sustainable Agriculture", located in Montgomery County, Pennsylvania.

Sustainable agriculture is a topic in international policy concerning its potential to reduce environmental risks. In 2011, the Commission on Sustainable Agriculture and Climate Change, as part of its recommendations for policymakers on achieving food security in the face of climate change, urged that sustainable agriculture must be integrated into national and international policy. The Commission stressed that increasing weather variability and climate shocks will negatively affect agricultural yields, necessitating early action to drive change in agricultural production systems towards increasing resilience. It also called for dramatically increased investments in sustainable agriculture in the next decade, including in national research and development budgets, land rehabilitation, economic incentives, and infrastructure improvement.

European Union

In May 2020 the European Union published a program, named "From Farm to Fork" for making its agriculture more sustainable. In the official page of the program From Farm to Fork is cited Frans Timmermans the Executive Vice-President of the European Commission, saying that:

"The coronavirus crisis has shown how vulnerable we all are, and how important it is to restore the balance between human activity and nature. At the heart of the Green Deal the Biodiversity and Farm to Fork strategies point to a new and better balance of nature, food systems, and biodiversity; to protect our people's health and well-being, and at the same time to increase the EU's competitiveness and resilience. These strategies are a crucial part of the great transition we are embarking upon."

The program includes the next targets:

China

In 2016, the Chinese government adopted a plan to reduce China's meat consumption by 50%, for achieving more sustainable and healthy food system.

United States

In the United States, the federal Natural Resources Conservation Service provides technical and financial assistance for those interested in pursuing natural resource conservation along with production agriculture. With programs like SARE and China-UK Sustainable Agriculture Innovation Network to help promote research on sustainable agriculture practices and a framework for agriculture and climate change respectively.

Mexico

In 2020 Mexico banned the domestic growing of GMO corn and announced a future ban on import by 2024. According to the announcement, the use of Glyphosate will also be banned by the same year.

Criticism

Among 63 farmers interviewed in Tasmania most accepted the notion climate change was happening, but just a small segment believed that it was human-related. Few farmers thought that the issue of climate change was significant enough to diminish what was causing it. Some of the farmers were worried about how a suggested carbon dioxide reduction plan would affect the agricultural sector and were suspicious of numerous government related activities, seeing them as methods in which the government could punish producers. The author James Howard Kunstler claims almost all modern technology is bad and that there cannot be sustainability unless agriculture is done in ancient traditional ways. Efforts toward more sustainable agriculture are supported in the sustainability community, however, these are often viewed only as incremental steps and not as an end. Some foresee a true sustainable steady state economy that may be very different from today's: greatly reduced energy usage, minimal ecological footprint, fewer consumer packaged goods, local purchasing with short food supply chains, little processed foods, more home and community gardens, etc.

According to Michael Carolan, a major barrier to the adoption of sustainable agriculture is its appearance of a lack of benefits. Many benefits are not visible or immediately evident, and affecting changes such as lower rates of soil and nutrient loss, improved soil structure and higher levels of beneficial microorganisms takes time. In conventional agriculture the benefits are easily visible with no weeds, pests, etc. and the costs to soil and ecosystems around it are hidden and "externalised".

Entropy (information theory)

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Entropy_(information_theory) In info...