The use of tobacco has a very adverse effect on human health and concerns about the health effects of tobacco have a long history. Research has focused primarily on tobacco smoking. In 1950, Richard Doll published a study in the British Medical Journal showing a close connection between smoking and lung cancer. Four years later, in 1954, the British Physician Study, a study of about 40,000 doctors over 20 years, confirmed the suggestion, based on government advice that smoking and lung cancer rates were linked.
Tobacco smoke contains more than fifty chemicals that cause cancer. Tobacco also contains nicotine, which is a highly addictive psychoactive drug. When tobacco is smoked, nicotine causes physical and psychological dependence. Cigarettes sold in underdeveloped countries tend to have higher tar content, and are less likely to be filtered, potentially increasing susceptibility to tobacco-related diseases in the region.
Tobacco use is the biggest cause of death that can be prevented globally. As many as half of people who use tobacco die from complications of tobacco use. The World Health Organization estimates that every year tobacco causes about 6 million deaths (about 10% of all deaths) with 600,000 of which occur in nonsmokers due to second cigarette smoke. In the 20th century, tobacco was thought to have caused 100 million deaths. Similarly, the US Centers for Disease Control and Prevention describes the use of tobacco as "the single most important preventable risk to human health in developed countries and an important cause of premature death worldwide." According to a 2014 review in the New England Journal of Medicine, tobacco will, if current smoking patterns persist, kill about 1 billion people in the 21st century, half of them before the age of 70.
Tobacco use most often leads to diseases that affect the heart, liver, and lungs. Smoking is a major risk factor for heart attacks, strokes, chronic obstructive pulmonary disease (COPD) (including emphysema and chronic bronchitis), and some cancers (especially lung, laryngeal and mouth cancers, bladder cancer, and pancreatic cancer). It also causes peripheral arterial disease and high blood pressure. The effect depends on the number of years a person smokes and how many people smoke. Start smoking earlier in life and smoking higher on tar increases the risk of these diseases. Also, environmental tobacco smoke, or passive smoking, has been shown to cause adverse health effects in people of all ages. Tobacco use is a significant factor in miscarriage among pregnant smokers, and this contributes to a number of other fetal health problems such as premature birth, low birth weight, and an increase of 1.4 to 3 times the likelihood of sudden infant death syndrome (SIDS). ). The incidence of erectile dysfunction is about 85 percent higher in male smokers compared to non-smokers.
Some countries have taken action to control tobacco consumption with restrictions on use and sales as well as warning messages printed on the packaging. In addition, non-smoking legislation prohibiting smoking in public places such as workplaces, theaters, and bars and restaurants reduces exposure to other people's cigarette smoke and helps some people who smoke to quit smoking, without negative economic effects on restaurants or bars. Tobacco taxes that increase prices are also effective, especially in developing countries.
Video Health effects of tobacco
Health effects of smoking
Smoking most often causes diseases affecting the heart and lungs and most often affects areas such as the hands or feet with the first signs of smoking-related health problems that appear as numbness, smoking being a major risk factor for heart attacks, chronic obstructive pulmonary disease ( COPD), emphysema, and cancer, especially lung cancer, laryngeal and oral cancer, and pancreatic cancer. Overall life expectancy is also reduced in long-term smokers, with estimates ranging from 10 to 17.9 years less than nonsmokers. About half of long-term male smokers will die of smoking. The association of smoking with lung cancer is the strongest, both in public perception and in aetiology. Among male smokers, the lifetime risk for developing lung cancer was 17.2%; among women smokers, the risk is 11.6%. This risk is significantly lower in nonsmokers: 1.3% in men and 1.4% in women. Historically, lung cancer was considered a rare disease before World War I and is considered as something most doctors would never see during their careers. With the increasing popularity of postwar smoking came a virtual epidemic of lung cancer.
Increased risk of a person affected by disease is directly proportional to the length of time a person continues to smoke and the amount exposed. However, if a person stops smoking, then this opportunity gradually decreases as damage to his body is repaired. A year after quitting, the risk of contracting heart disease is half that of sustained smokers. Smoking health risks are not uniform in all smokers. The risk varies according to the amount of tobacco smoked, with those who smoke are at greater risk. Smoking called "light" cigarettes does not reduce the risk.
Mortality
Smoking is the cause of about 5 million deaths per year. This makes it the most common cause of preventable early death. One study found that male and female smokers lost on average 13.2 and 14.5 years of their lives. Others find the loss of lives 6.8 years. Each smoked cigarette is estimated to shorten the average life of 11 minutes. At least half of lifelong smokers die early from smoking. Smokers are three times more likely to die before the age of 60 or 70 years as non-smokers.
In the United States, smoking and exposure to tobacco smoke account for about one in five, or at least 443,000 premature deaths each year. To put this into context, Peter Jennings ABC famously reported that in the US alone, tobacco kills the equivalent of three jumbo jets filled with people who bump every day, with no survivors. Around the world, this is equivalent to one jumbo jet every hour.
A 2015 study found that about 17% of deaths from smoking in the United States are due to diseases other than those commonly believed to be related.
Cancer
The main risks of tobacco use include many forms of cancer, especially lung cancer, kidney cancer, laryngeal and head and neck cancer, bladder cancer, esophageal cancer, pancreatic cancer and stomach cancer. Studies have established a link between tobacco smoke, including passive smoking, and cervical cancer in women. There is some evidence to suggest an increased risk of myeloid leukemia, squamous cell sinonasal cancer, liver cancer, colorectal cancer, gallbladder cancer, adrenal glands, small intestine, and various cancers in childhood. The possible link between breast and tobacco cancers is uncertain.
The risk of lung cancer is strongly influenced by smoking with up to 90% of cases caused by tobacco smoking. The risk of developing lung cancer increases with the number of years smoking and the number of cigarettes smoked per day. Smoking can be associated with all subtypes of lung cancer. Small Cell Lung Carcinoma (SCLC) is most closely related to almost 100% of cases occurring in smokers. This form of cancer has been identified with autocrin growth loops, proto-oncogen activation and inhibition of tumor suppressor genes. SCLC can be derived from neuroendocrine cells located in the bronchus called Feyrter cells.
The risk of dying from lung cancer before the age of 85 is 22.1% for male smokers and 11.9% for female smokers, in the absence of a competitive cause of death. Appropriate estimates for lifelong non-smokers are 1.1% probability of death from lung cancer before age 85 for a man of European descent, and a probability of 0.8% for a woman.
Lung
In smoking, long-term exposure to compounds found in smoke (eg, carbon monoxide and cyanide) is believed to be responsible for lung damage and loss of elasticity in the alveoli, leading to emphysema and COPD. Chronic obstructive pulmonary disease (COPD) caused by smoking, is a permanent, incurable pulmonary capacity (often terminal) characterized by shortness of breath, wheezing, persistent coughing with sputum, and lung damage, including emphysema and chronic bronchitis. Akrolein carcinogens and their derivatives also contribute to chronic inflammation present in COPD.
Cardiovascular Disease
Inhaling tobacco smoke causes several direct responses in the heart and blood vessels. Within one minute, the heart rate began to increase, rising by 30 percent during the first 10 minutes of smoking. Carbon monoxide in tobacco smoke has a negative effect by reducing the ability of blood to carry oxygen.
Smoking also increases the likelihood of heart disease, stroke, atherosclerosis, and peripheral vascular disease. Some tobacco materials cause narrowing of blood vessels, increasing the likelihood of blockage, and thus heart attack or stroke. According to a study by an international team of researchers, people under 40 are five times more likely to have a heart attack if they smoke.
Exposure to tobacco smoke is known to increase oxidative stress in the body by various mechanisms, including thinning of plasma antioxidants such as vitamin C.
Recent research by American biologists has shown that cigarette smoke also affects the process of cell division in the heart muscle and changes the shape of the heart.
The use of tobacco has also been linked to the disease of Buerger ( thromboangiitis obliterans ) acute inflammation and thrombosis (freezing) of arteries and venous hands and feet.
Although smoking causes an increased risk of cancer greater than smoking cigars, cigar smokers still have an increased risk for many health problems, including cancer, when compared to non-smokers. For passive smokers, the NIH study shows a large amount of smoke produced by a cigar, saying "cigars can contribute large amounts of tobacco smoke to indoor environments, and, when large numbers of cigar smokers are swarming in cigar smoke, the number of ETS [ie passive smokers produced] enough to be of health concern to those who are regularly asked to work in the neighborhood. "
Smoking tends to increase blood cholesterol levels. Furthermore, the high-density lipoprotein ratio (HDL, also known as "good" cholesterol) to low-density lipoprotein (LDL, also known as "bad" cholesterol) tends to be lower in smokers than non-smokers. Smoking also increases fibrinogen levels and increases platelet production (both involved in blood clotting) that make the blood thicker and more likely to clot. Carbon monoxide binds to hemoglobin (the oxygen-carrying component in red blood cells), producing a stabler complex far from the hemoglobin bound by oxygen or carbon dioxide - the result is the loss of permanent blood cell function. Blood cells are naturally recycled after a period of time, allowing the creation of new functioning red blood cells. However, if carbon monoxide exposure reaches a certain point before they can be recycled, hypoxia (and then death) occurs. All of these factors make smokers more at risk of developing various forms of arteriosclerosis (hardening of the arteries). As the arteriosclerosis progresses, blood flow becomes easier through rigid and narrowed blood vessels, making the blood more likely to form thrombosis (blood clots). Sudden blockage of blood vessels can cause infarction (stroke or heart attack). However, it should also be noted that the effects of smoking on the heart may be more subtle. This condition may develop gradually in the cycle of smoking cure (the human body heals itself between the smoking period), and therefore a smoker may develop less significant disorders such as exacerbating or maintaining an unpleasant dermatological condition, such as eczema, due to reduced supply blood. Smoking also increases blood pressure and weakens blood vessels.
Renal
In addition to increasing the risk of kidney cancer, smoking can also contribute to additional kidney damage. Smokers are at a significantly increased risk for chronic kidney disease compared to non-smokers. Smoking history promotes the development of diabetic nephropathy.
Influenza
A study of influenza outbreaks (H1N1) in an Israeli military unit of 336 healthy young men to determine smoking association with clinical influenza events, revealed that of 168 smokers, 68.5 percent had influenza, compared with 47.2 percent instead of smoker. Influenza is also more severe in smokers; 50.6 percent of smokers lost working days or needed bed rest, or both, compared with 30.1 percent of nonsmokers.
According to a study of 1,900 male cadets after the 1968 Hong Kong A2 influenza epidemic in South Carolina military academy, compared with nonsmokers, heavy smokers (more than 20 cigarettes a day) had 21% more disease and 20% more rest in bed, light smokers (less than 20 cigarettes per day) have 10% more illness and 7% more rest.
The influence of smoking on influenza epidemics is prospectively studied among 1,811 male students. Clinical influenza incidence among those who smoke every day 21 or more cigarettes is 21% higher than non-smokers. Influenza events among smokers 1 to 20 cigarettes per day are among non-smokers and heavy smokers.
Supervision of the influenza outbreak of 1979 at a military base for women in Israel revealed that influenza symptoms developed in 60.0% of current smokers vs 41.6% of nonsmokers.
Smoking appears to cause relatively higher risk of influenza in older populations than in younger populations. In a prospective study of people living in communities aged 60-90 years, during 1993, of unimmunized people, 23% of smokers had clinical influenza compared with 6% of non-smokers.
Smoking can substantially contribute to the growth of an influenza epidemic affecting the entire population. However, the proportion of influenza cases in the general non-smoking population caused by smokers has not been calculated.
Oral
Perhaps the most serious oral condition that can arise is oral cancer. However, smoking also increases the risk of various other oral diseases, some almost completely exclusively for tobacco users. The National Institutes of Health, through the National Cancer Institute, determined in 1998 that "smoking cigars causes various cancers including oral cavity cancer (lips, tongue, mouth, throat), esophagus, larynx, and lung." Smoking pipes involves significant health risks, especially oral cancer. About half of the periodontitis or inflammation around tooth cases is associated with current or previous smoking. Smokeless tobacco causes gingival recession and white mucosal lesions. Up to 90% of patients with untreated periodontitis by way of general treatment are smokers. Smokers are significantly more likely to lose bone height than nonsmokers, and this trend can be extended to pipe smokers to have more bone loss than nonsmokers.
Smoking has proven to be an important factor in dye staining. Bad breath or bad breath is common among smokers of tobacco. Dental loss has been shown to be 2 to 3 times higher in smokers than in non-smokers. In addition, further complications may include leukoplakia, plaque white plaque or patches on the mucous membranes of the oral cavity, including the tongue.
Infection
Smoking is also associated with susceptibility to infectious diseases, especially in the lungs (pneumonia). Smoking more than 20 cigarettes a day increases the risk two to four times, and being a current smoker has been associated with a fourfold increase in the risk of invasive disease caused by pathogenic bacteria Streptococcus pneumoniae . It is believed that smoking increases the risk of lung and respiratory infections both through structural damage and through effects on the immune system. Effects on the immune system include increased production of nicotine-induced CD4 cell, which is temporarily associated with increased HIV vulnerability.
Smoking increases the risk of Kaposi's sarcoma in people without HIV infection. One study found this only with the male population and was unable to draw conclusions for female participants in the study.
Impotence
Incidence of impotence (difficulty reaching and maintaining a penile erection) is about 85 percent higher in male smokers compared with non-smokers. Smoking is a major cause of erectile dysfunction (ED). It causes impotence because it promotes arterial narrowing and damages cells lining the inside of the arteries, causing a decrease in penile blood flow.
Female infertility
Smoking is harmful to the ovaries, potentially causing female infertility, and the extent of damage depends on the amount and length of time a woman smokes. Nicotine and other harmful chemicals in cigarettes interfere with the body's ability to create estrogen, the hormone that governs folliculogenesis and ovulation. Also, smoking cigarettes interfere with follicologenesis, embryonic transport, endometrial receiving power, endometrial angiogenesis, uterine blood flow and uterine myometrium. Some damage can not be changed, but quitting smoking can prevent further damage. Smokers are 60% more likely to be infertile than non-smokers. Smoking reduces the likelihood of in vitro fertilization (IVF) results in a live birth of 34% and increases the risk of miscarriage of IVF by 30%.
Psychological
American psychologists stated, "Smokers often report that smoking helps to alleviate stress, but adult smokers' stress levels are slightly higher than non-smokers, teen smokers report increased stress levels as they develop regular smoking patterns, and quit smoking. stress, far from acting as an aid to mood control, nicotine dependence seems to exacerbate stress.This is confirmed in the daily mood patterns described by smokers, with a normal mood during smoking and a worsening atmosphere between smoking cigarettes only reflects the tension and irritability reversal that develops during the reduction of nicotine.Content smokers need nicotine to remain normal. "
Effect immediately
Users report feelings of relaxation, sharpness, tranquility, and alertness. The new smokers may experience nausea, dizziness, increased blood pressure, narrowed arteries, and rapid heart beat. Generally, unpleasant symptoms will eventually disappear over time, with repeated use, because the body builds tolerance to chemicals in cigarettes, such as nicotine.
Stress
Smokers report higher levels of daily stress. Several studies have monitored the feelings of stress over time and found less stress after quitting.
The damaging mood effects of abstinence explain why smokers suffer more daily stress than nonsmokers and become less stressed when they quit smoking. The deprivation cycle also explains a lot of passionate data, with smokers who lack less alert and less alert than smokers who are not smokers or non-smokers.
Recent studies have shown a positive relationship between psychological stress and salivary cotinine levels in smoking and non-smoking adults, suggesting that both direct and second-hand smoke exposure can lead to higher levels of mental stress.
Social and behavior
Medical researchers have found that smoking is a divorce predictor. Smokers have a 53% greater chance of getting divorced than nonsmokers.
Cognitive function
Tobacco use can also create cognitive dysfunction. There appears to be an increased risk of Alzheimer's disease, although "case studies and cohort controls yield conflicting results regarding the direction of the relationship between smoking and AD". Smoking has been found to contribute to dementia and cognitive decline, reducing memory and cognitive abilities in adolescents, and brain shrinkage (cerebral atrophy).
In particular, several studies have found that patients with Alzheimer's disease are more likely to not smoke than the general population, which has been interpreted to suggest that smoking offers protection against Alzheimer's. However, research in this area is limited and the results are contradictory; several studies have shown that smoking increases the risk of Alzheimer's disease. A recent review of available scientific literature concludes that a marked reduction in Alzheimer's risk may be simply because smokers tend to die before reaching the age at which Alzheimer's usually occurs. "Differential mortality always tends to be a problem where there is a need to investigate the effects of smoking in disorders with very low incidence rates before the age of 75 years, which is a case of Alzheimer's disease," he noted, noting that smokers are only half of people who do not smoke to survive live until the age of 80 years.
Some longer analyzes suggest that non-smokers are twice as likely as smokers to develop Alzheimer's disease. However, a more recent analysis finds that most studies, which show a preventive effect, have a close relationship with the tobacco industry. Researchers without the influence of the tobacco lobby have concluded the opposite: Smokers are almost twice as likely as non-smokers to develop Alzheimer's disease.
Former and current smokers have a lower incidence of Parkinson's disease compared to people who never smoked, although the authors state that it is more likely that movement disorders that are part of Parkinson's disease prevent people from smoking than smoking itself. protector. Another study considers the possible role of nicotine in reducing Parkinson's risk: nicotine stimulates the brain dopaminergic system, which is damaged in Parkinson's disease, while other compounds in tobacco smoke inhibit MAO-B, an enzyme that produces oxidative radicals by breaking down dopamine..
In many ways, nicotine works on the nervous system in a similar way to caffeine. Some writings suggest that smoking can also increase mental concentration; one study documented significantly better performance in the normalized Raven Progressive Matrices test after smoking.
Most smokers, when they deny access to nicotine, exhibit withdrawal symptoms such as irritability, anxiety, dry mouth, and rapid heartbeat. The onset of these symptoms is very rapid, the nicotine part-time is only 2 hours. Psychological dependence can last for months or even years. Unlike some drugs, nicotine does not significantly alter smokers' motor skills, judgment, or language skills when under the influence of drugs. Withdrawal of tobacco has been shown to cause clinically significant distress.
A very high percentage of schizophrenia smokes tobacco as a form of self-medication. The high rate of tobacco use by the mentally ill is a major factor in the decline in their life expectancy, which is about 25 years shorter than the general population. After the observation that smoking increases the condition of people with schizophrenia, particularly in memory deficits, nicotine patches have been proposed as a way to treat schizophrenia. Some studies show that there is a link between smoking and mental illness, citing the high incidence of smoking among those suffering from schizophrenia and the possibility that smoking may alleviate some of the symptoms of mental illness, but this is not conclusive. By 2015, meta-analysis found that smokers are at greater risk of developing psychotic illnesses.
Recent studies have linked smoking with anxiety disorders, suggesting a correlation (and possibly mechanism) may be related to a broad class of anxiety disorders, and not limited to just depression. Current and ongoing research efforts to explore the relationship of addictions. Data from various studies show that anxiety disorders and depression play a role in smoking. A regular smoking history is observed more frequently among individuals who have experienced major depression disorders at some point in their lives than among individuals who have never experienced major depression or among individuals without psychiatric diagnosis. People with severe depression are also very unlikely to quit because of the increased risk of mild to severe depression, including episodes of major depression. Depressed smokers seem to experience more withdrawal symptoms at stops, tend to be unsuccessful, and more likely to recur.
Pregnancy
Numerous studies have shown that tobacco use is a significant factor in miscarriage among pregnant smokers, and it contributes to a number of other threats to fetal health. This slightly increases the risk of neural tube defects.
Exposure to environmental tobacco smoke and maternal smoking during pregnancy has been shown to cause lower birth weight infants.
Studies have shown a link between prenatal exposure to environmental tobacco smoke and disorder in children. In addition, exposure to post-partum smoking can cause similar behavioral problems in children.
Drug interactions
Smoking is known to increase the level of liver enzymes that break down drugs and toxins. That means that the medicines cleared by these enzymes are cleaned faster in smokers, which can cause the drugs to malfunction. Specifically, CYP1A2 and CYP2A6 levels are induced: the substrate for 1A2 includes caffeine and tricyclic antidepressants such as amitriptyline; substrate for 2A6 including anticonvulsant, valproic acid.
Multigenerational effects
Other damage
Studies show that smoking reduces appetite, but does not conclude that overweight people should smoke or that their health will improve by smoking. It is also a cause of heart disease. Smoking also loses weight by overexpressing the AZGP1 gene that stimulates lipolysis.
Smoking accounts for about 10% of the global burden of death from fires, and smokers are placed at an increased risk of injury-related deaths in general, partly because of an increased risk of death in motor vehicle accidents.
Smoking increases the risk of symptoms associated with Crohn's disease (dose-dependent effects with the use of more than 15 cigarettes per day). There is some evidence for decreased levels of endometriosis in infertile women smoking, although other studies have found that smoking increases the risk in infertile women. There is little or no evidence of protective effect on fertile women. Some preliminary data from 1996 suggest a reduction in the incidence of uterine fibroids, but overall evidence is inconclusive.
Recent research has shown that tobacco smokers exposed to residential radon are twice as likely to develop lung cancer as nonsmokers. In addition, the risk of developing lung cancer from asbestos exposure is twice as likely for smokers than for non-smokers.
New research has found that women who smoke significantly increase the risk of developing a stomach aortic aneurysm, a condition in which the weak area of ​​the abdominal aorta extends or protrudes, and is the most common form of aortic aneurysm.
Smoking causes an increased risk of fractures, especially hip fractures. It also leads to slower wound healing after surgery, and increased levels of postoperative healing complications.
Benefits
In addition to the many documented negative health effects of smoking, certain types of "smoker paradox" (cases where smoking appears to have certain beneficial effects) have been observed. Smoking can prevent Parkinson's disease.
Maps Health effects of tobacco
Mechanism
Chemical carcinogens
Smoke, or partially burnt organic matter, contains carcinogens (cancer-causing agents). The potential effects of smoking, such as lung cancer, can take up to 20 years to manifest itself. Historically, women start smoking en masse more slowly than men, so the increased mortality rate caused by smoking among women does not appear until later. Male lung cancer death rate declined in 1975 - about 20 years after the initial decline in cigarette consumption in men. The decline in consumption in women also began in 1975 but in 1991 did not manifest in the reduction of lung cancer-related mortality among women.
Smoke contains some carcinogenic pyrolytic products that bind to DNA and cause genetic mutations. Potent carcinogens are polycyclic aromatic hydrocarbons (PAHs), which are oxidized to mutagenic epoxides. The first PAH identified as a carcinogen in tobacco smoke is benzopiren, which has been shown to be toxic to epoxides that are irreversibly attached to the cell's nuclear DNA, which can kill cells or cause genetic mutations. If the mutations inhibit programmed cell death, the cell can survive into cancer cells. Similarly, acrolein, which is abundant in tobacco smoke, also binds DNA irreversibly, causing mutations and also cancer. However, there is no need for activation to be carcinogenic.
There are more than 19 known carcinogens in cigarette smoke. Here are some of the most powerful carcinogens:
- Polycyclic aromatic hydrocarbons are the tar components produced by pyrolysis in the smoldering of organic matter and emitted into the smoke. Some of these PAHs are already toxic in their normal form, but many of them can become more toxic to the liver. Due to the hydrophobic nature of PAHs, they do not dissolve in water and are difficult to remove from the body. To make PAHs more soluble in water, the liver creates an enzyme called Cytochrome P450 which adds additional oxygen to the PAH, converting it into mutagenic epoxides, which are more soluble, but also more reactive. The first PAH identified as a carcinogen in tobacco smoke is benzoprene, which has been shown to be toxic to diol epoxide and then permanently attached to nuclear DNA, which can kill cells or cause genetic mutations.. DNA contains information about how the cell functions; in practice, it contains a recipe for protein synthesis. If the mutations inhibit programmed cell death, the cell can survive into cancer cells, cells that do not function like normal cells. Carcinogenicity is radiomimetic, similar to that produced by ionizing nuclear radiation. Tobacco manufacturers have experimented with less vaporizer burning technology to allow cigarettes to be consumed without the formation of carcinogenic benzoprenin. Although the product has become increasingly popular, the product still represents a small portion of the market, and there is no conclusive evidence proven to prove or disprove positive health claims.
- Acrolein is a pyrolysis product widely present in cigarette smoke. It provides a pungent odor of smoke and a tantalizing effect of tears and is a major contributor to its carcinogenicity. Like the PAH metabolite, acrolein is also an electrophilic alkylation agent and binds permanently to the DNA base guanine, by addition of conjugation followed by cyclization to hemiamina. The acrolein-guanine adduct induces mutations during DNA copy and thus causes cancer in a manner similar to PAH. However, acrolein is 1000 times more than the PAH in cigarette smoke and is able to react as it is, without activation of metabolism. Akrolein has been shown to be a mutagen and a carcinogen in human cells. Carcinogenicity of acrolein is difficult to study through animal experiments, because it has toxicities that tend to kill animals before they develop cancer. Generally, a compound capable of reacting with the addition of a conjugate as an electrophile (called Michael acceptor after Michael's reaction) is toxic and carcinogenic, since they can permanently alkylate the DNA, similar to the gas mustard or aflatoxin. Acrolein is just one of those present in cigarette smoke; for example, crotonaldehyde has been found in cigarette smoke. Michael acceptor also contributes to the chronic inflammation present in tobacco diseases.
- Nitrosamines are a group of carcinogenic compounds found in cigarette smoke but not in un-preserved tobacco leaves. Nitrosamines are formed on tobacco leaves that are dried by fire during the curing process through chemical reactions between nicotine and other compounds contained in uncured leaves and various nitrogen oxides found in all combustion gases. Switching to indirect fire curing has been shown to reduce nitrosamine levels to less than 0.1 parts per million.
Tobacco smoke tobacco, or the main smoke exhaled, is very dangerous. Because the spent fumes are present at lower temperatures than inhaled smoke, chemical compounds undergo changes that can make them more dangerous. In addition, smoke changes with age, leading to the transformation of NO to NO more toxic compounds 2 . Furthermore, volatilization causes the smoke particles to become smaller, and thus more easily embedded deep into the lungs of anyone who then inhaling the air.
Radioactive carcinogens
In addition to chemical carcinogens, nonradioactive carcinogens, tobacco and tobacco smoke contain small amounts of 210 lead ( 210 Pb) and polonium-210 ( 210 Po) both of which are radioactive. carcinogens. The presence of polonium-210 in main cigarette smoke has been measured experimentally at a level of 0.0263-0.036 pCi (0.97-1.33 mBq), which is equivalent to about 0.1 pCi per milligram of smoke (4 mBq/mg); or about 0.81 pCi of lead-210 per gram of viscous thick smoke (30 Bq/kg).
Research by NCAR radiologist Ed Martell suggests that radioactive compounds in cigarette smoke are stored in "hot spots" where bronchial tube branches, that the tar of cigarette smoke is resistant to dissolution in the lung fluid and that radioactive compounds have plenty of time to undergo radioactivity. decay before being cleansed by natural processes. Indoors, these radioactive compounds can survive in passive smokers, and greater exposure will occur when these radioactive compounds are inhaled during normal breathing, which is deeper and longer than when inhaling cigarettes. Damage to protective epithelial tissue from smoking only increases the prolonged retention of insoluble polonium-210 compounds produced from tobacco burning. Martell estimates that a dose of carcinogenic radiation of 80-100 rads is sent to the lung tissue of most smokers who die of lung cancer.
Smoking an average of 1.5 packs per day gives a radiation dose of 60-160 mSv/year, compared to living near a nuclear power plant (0.0001 mSv/year) or a median average dose of 3.0 mSv/year for American. Some apatite minerals in Florida are used to produce phosphates for US tobacco plants containing uranium, radium, lead-210 and polonium-210 and radon. Radioactive smoke from tobacco that is fertilized in this way is stored in the lungs and releases radiation even if a smoker stops the habit. The combination of carcinogenic tar and radiation in sensitive organs such as the lung increases the risk of cancer.
In contrast, a 1999 review of tobacco smoke carcinogens published in the Journal of the National Cancer Institute states that "the level of polonium-210 in tobacco smoke is not believed to be large enough to significantly impact lung cancer in smokers." In 2011 Hecht also stated that "Po <210 levels in cigarette smoke may be too low to engage in lung cancer induction..."
Nicotine
Nicotine, which is contained in cigarettes and other tobacco smoke products, is a stimulant and is one of the main factors that cause tobacco smoking continuously. Nicotine is a highly addictive psychoactive chemical. When tobacco is smoked, most of the nicotine undergoes pyrolysis; sufficient doses to cause mild somatic dependence and mild to strong psychological dependence persist. The amount of nicotine absorbed by the body from cigarettes depends on many factors, including the type of tobacco, whether the smoke is inhaled, and whether the filter is used. There is also the formation of a harmane (MAO inhibitor) of acetaldehyde in cigarette smoke, which seems to play an important role in nicotine addiction perhaps by facilitating the release of dopamine in the nucleus accumbens in response to nicotine stimulation. According to studies by Henningfield and Benowitz, nicotine is more addictive than marijuana, caffeine, ethanol, cocaine, and heroin when considering somatic and psychological dependence. However, because of the stronger withdrawal effects of ethanol, cocaine and heroin, nicotine may have a lower potential for somatic dependence than these substances. About half of Canada's current smokers have tried to quit. McGill University health professor Jennifer O'Loughlin states that nicotine addiction can occur as soon as five months after the start of smoking.
Swallowing compounds with smoking is one of the quickest and most efficient methods to get it into the bloodstream, second only to injection, allowing rapid feedback that supports the ability of smokers to titrate their doses. On average it takes about ten seconds for the substance to reach the brain. As a result of the efficiency of this delivery system, many smokers feel as if they can not stop. Of those who try to quit and the last three months without succumbing to nicotine, most can remain smoke-free for the rest of their lives. There is a possibility of depression in some people who try to quit, as do other psychoactive substances. Depression is also common in adolescent smokers; adolescents who smoked four times more likely to develop depressive symptoms as their peers who do not smoke.
Although nicotine plays a role in acute episodes of several diseases (including stroke, impotence, and heart disease) with the stimulation of adrenaline release, which increases blood pressure, heart rate and respiration, and free fatty acids, the most serious long-term effects. more results from burning burning process products. This leads to the development of various nicotine-delivery systems, such as nicotine or nicotine gum, which can satisfy the addictive desire by giving nicotine without harmful by-products. This can help highly dependent smokers to stop gradually, while stopping further damage to health.
Recent evidence suggests that tobacco smoking increases the release of dopamine in the brain, especially in mesolimbic pathways, the same neuro-reward circuit activated by drug abuse such as heroin and cocaine. This suggests the use of nicotine has a pleasant effect that triggers positive reinforcement. One study found that smokers showed better reaction time and memory performance compared with non-smokers, which is consistent with increased activation of dopamine receptors. Neurologically, rodent studies have found that giving nicotine causes a reduced threshold of reward - a discovery that is contrary to most other drug abuse (eg cocaine and heroin).
Carcinogenicity of tobacco smoke is not explained by nicotine per se, which is not carcinogenic or mutagenic, although it is a metabolic precursor for some compounds. In addition, it inhibits apoptosis, thus accelerating the existing cancer. Also, NNK, nicotine derived from nicotine, may be carcinogenic.
It should be noted that nicotine, although often involved in producing tobacco addiction, is less addictive when it is self-administered. The potential for addiction manifests itself after co-administration of MAOI, which in particular leads to sensitization of locomotor responses in mice, an addictive measure of potential.
Forms of exposure
Passive smokers
Secondhand smoke is a mixture of smoke from the burning tip of the cigarette, pipe or cigar, and smoke exhaled from the lungs of smokers. Unconsciously inhaled, staying alive in the air a few hours after the cigarette is extinguished, and can cause various adverse health effects, including cancer, respiratory infections and asthma. Non-smokers exposed to secondhand smoke at home or work are considered, due to various statistical studies, to increase their risk of heart disease by 25-30% and their lung cancer risk by 20-30%. Passive smoking is estimated to cause 38,000 deaths per year, of which 3,400 deaths from lung cancer in nonsmokers.
The current US Surgeon General's report concludes that no risk-free level of exposure has been established for passive smokers. Short exposure to passive smokers is believed to cause blood platelets to become more sticky, damage blood vessels, lower coronary flow reserves, and reduce heart rate variability, potentially increasing the risk of heart attack. New research shows that private research conducted by cigarette company Philip Morris in the 1980s shows that passive smoking is toxic, but the company is pressing the find for the next two decades.
Chewing tobacco
Chewing tobacco has been known to cause cancer, especially in the mouth and throat. According to the International Agency for Research on Cancer, "Some health scientists have suggested that smokeless tobacco should be used in smoking cessation programs and have made implicit or explicit claims that its use would reduce some of the smokers' exposure to carcinogens and cancer risk. evidence available. "Oral tobacco and saliva increase the risk of leukoplakia as a precursor to oral cancer.
Cigar
Like other forms of smoking, smoking a cigar poses a significant health risk depending on the dose: greater risk for those who inhale more when they smoke, smoke more cigars, or smoke longer. The risk of death from any cause is significantly greater for cigar smokers, with a particularly high risk for smokers younger than 65, and with the risk of moderate and deeper inhalers reaching levels similar to cigarette smokers. The increased risk for those who smoked 1-2 cigars per day was too small to be statistically significant, and the health risks of 3/4 cigar smokers who smoked less than a day were unknown and difficult to measure. Although it has been claimed that people who smoke some cigars do not have an increased risk, a more accurate statement is that their risk is proportional to their exposure. Health risks are similar to smoking in nicotine addiction, periodontal health, tooth loss, and many types of cancers, including cancers of the mouth, throat, and esophagus. Smoking cigars can also cause lung and laryngeal cancer, where the increased risk is less than cigarettes. Many of these cancers have very low cure rates. Cigar smoking also increases the risk of lung and heart diseases such as chronic obstructive pulmonary disease.
Hookah
The common belief among users is that hookah smoke (water pipe, narghile) is significantly more dangerous than cigarettes. The water humidity caused by the hookahs makes the smoke less annoying and can provide the wrong sense of safety and lessen concern about the actual health effects. Doctors at institutions including the Mayo Clinic have stated that the use of hookah may harm a person's health such as smoking, and a study by the World Health Organization also confirmed these findings.
Each hookah session usually lasts more than 40 minutes, and consists of 50 to 200 draws, each ranging from 0.15 to 0.50 liters of smoke. In a one-hour hookah smoking session, users consume about 100 to 200 times a single cigarette smoke; A study in the Journal of Periodontology found that pipe smokers were marginally more likely than regular smokers to show signs of gum disease, suggesting a 5-fold higher rate than non-smokers than a 3.8-fold risk. that regular smokers appear. According to USA Today, people who smoke water pipes have five times the risk of non-smoker lung cancer.
A study of hookah smoking and cancer in Pakistan was published in 2008. The aim was "to find serum CEA levels in hookah/exclusive smokers, ie those who smoked only hookah (no cigarettes, bidis, etc.), prepared between 1 and 4 times daily with up to 120 g of tobacco-molasses each (ie tobacco weight equivalent to 60 cigarettes 1 g each) and consumed in 1 to 8 sessions. " Carcinoembryonic antigen (CEA) is a marker found in some forms of cancer. Levels in exclusive hookah smokers were lower than among smokers although the differences were not statistically significant as between hookah smokers and non-smokers. Also, the study concluded that heavy hookah smoking (2-4 daily preparations, 3-8 sessions per day, & gt; 2 hours to <= 6 hours) substantially increased levels of CEA. Hookah smokers are nearly 6 times more likely to develop lung cancer compared to people who do not smoke in Kashmir (India).
Dipping tobacco
Dipping tobacco, commonly referred to as tobacco, is also incorporated into the mouth, but it is a flavored powder. it is placed between cheeks and chewing gum. Dipping tobacco does not need to be chewed because nicotine is absorbed into your body. The first time users of this product often become nauseous and dizzy. Long-term effects include bad breath, yellow teeth, and an increased risk of oral cancer.
Users dipping tobacco are believed to be at lower risk of some cancers than smokers but still have a greater risk than people who do not use tobacco products. They also have the same risk to other health problems that are directly related to nicotine such as increased levels of atherosclerosis.
Prevention
Education and counseling by pediatricians and doctors has proven effective in reducing the risk of tobacco use.
Usage
Although tobacco can be consumed either by smoking or other smokeless methods such as chewing, the World Health Organization (WHO) only collects data about tobacco being smoked. Therefore, smoking has been studied more widely than other forms of tobacco consumption.
In 2000, smoking was practiced by 1.22 billion people, predicted to rise to 1.45 billion people in 2010 and 1.5 to 1.9 billion by 2025. If prevalence declines 2% a year since 2000 this figure will be 1, 3 billion in 2010 and 2025. Despite down 0.4 percent from 2009 to 2010, the United States still reports an average of 17.9 percent usage.
In 2002, about twenty percent of teenagers (13-15) smoked around the world, with 80,000 to 100,000 children taking addiction each day - about half of whom live in Asia. Half of those who start smoking in adolescence are projected to smoke for 15 to 20 years.
WHO states that "Most of the burden of disease and premature death caused by tobacco use disproportionately affect the poor". Of the 1.22 billion smokers, 1 billion of them live in developing countries or transitional countries. Smoking rates have declined or decreased in developed countries. But in developing countries, tobacco consumption rose 3.4% annually in 2002.
WHO in 2004 projected 58.8 million deaths globally, from 5.4 million attributable to tobacco, and 4.9 million in 2007. In 2002, 70% of deaths occurred in developing countries.
The shift in the prevalence of tobacco smoking to younger demographics, especially in developing countries, can be attributed to several factors. The tobacco industry spends up to $ 12.5 billion annually on advertising, which is increasingly geared towards teenagers in the developing world because they are a very vulnerable audience for marketing campaigns. Adolescents have more difficulty understanding the long-term health risks associated with smoking and are also more easily affected by "the image of romance, success, sophistication, popularity, and adventure that advertising suggests they can achieve through cigarette consumption". The shift in marketing to teenagers and even children in the tobacco industry undermines the efforts of organizations and countries to improve child health and mortality in developing countries. This reverses or stops the impact of work already undertaken to improve health care in these countries, and although smoking is considered a "voluntary" health risk, tobacco marketing to highly influenced adolescents in developing countries makes it less than voluntary and more than inevitable shifts.
Many government regulations are passed to protect citizens from harm caused by tobacco smoke in the community environment. The "Pro-Children Act of 2001" prohibits smoking in all facilities that provide health care, child care, library services, or primary and secondary education for children in the US. On May 23, 2011, New York City imposed a smoking ban for all parks, beaches and pedestrian malls in an attempt to eliminate threats posed to civilians by environmental tobacco smoke.
History
Concerns about the health effects of tobacco have a long history. Gideon Lincecum, an American naturalist and practitioner of botanical medicine, wrote in the early 19th century about tobacco: "This poisonous plant has been used extensively as a cure by the faculty of old school, and thousands have been killed by it... This is a very dangerous article , and use it as it should, it always reduces vital energy in the right proportion to the quantity used - it may be slow, but very definite. "
The invention of the late 19th century automatic cigarette makers in South America made it possible to produce cigarettes in bulk at low cost, and cigarettes became elegant and fashionable among the people when the Victorian era gave way to the Edwardian. In 1912, Dr. Isaac Adler of America is the first to state that lung cancer is associated with smoking. In 1924, economist Irving Fisher wrote an anti-smoking article for Readers Digest, which says "... tobacco lowered the whole body tone and lowered its vital strength and endurance... tobacco-like acts like narcotic toxins, such as opium, and like alcohol, although usually at a lower level.In 1929, Fritz Lickint of Dresden, Germany, published formal statistical evidence of the association of lung cancer, based on a study showing that lung cancer patients tend to become smokers Lickint also argues that tobacco use is the best way to explain the fact that lung cancer attacks men four or five times more often than women (because women smoke far less).
Before World War I, lung cancer was considered a rare disease, which most doctors would never see during their careers. With the increasing popularity of postwar cigarettes, however, came the epidemic of lung cancer. National Cancer Institute. "20 Years Lag Time Between Smoking and Lung Cancer". Archived from the original on.
In 1950, Richard Doll and Austin Bradford Hill published a study in the British Medical Journal showing a strong link between smoking and lung cancer. Four years later, in 1954, the British Physician Study, a study of about 40,000 doctors over 20 years, confirmed the suggestion, based on government advice that smoking and lung cancer rates were linked. The British Doctors Study lasted until 2001, with results published every ten years and the final results published in 2004 by Doll and Richard Peto. Many early studies were also conducted by Alton Ochsner. Reader's Digest magazine has for years published frequent anti-smoking articles. On January 11, 1964, the Surgeon General United States Report on Smoking and Health was published; this causes millions of American smokers to quit, banning certain advertisements, and warning labels on tobacco products.
Study
In the 1930s German scientists showed that smoking causes lung cancer. In 1938, a study in the United States by Johns Hopkins University scientists showed a very negative correlation between smoking and lifetime. In 1950 five studies were published in which "smoking has strong implications for the cause of lung cancer". These include the classic "Smoking and Lung Carcinoma" paper that appears in the British Medical Journal . The paper reports that "heavy smokers are fifty times as likely as non-smokers to develop lung cancer".
The Wynder and Graham Study 1950, entitled "Tobacco Smoking as a Possible Etiology Factor in Bronchiogenic Carcinoma: A Study of Six Hundred and Eighty Four Proven Cases", concludes that long-term tobacco use contributes to the onset of lung cancer.
In 1953, scientists at the Sloan-Kettering Institute in New York City showed that cigarette tar painted on mice's skin caused a deadly cancer. This work attracted much media attention; New York Times and Life both discuss this issue. The Reader's Digest publishes an article titled "Cancer by the Carton".
A team of British scientists led by Richard Doll conducted a longitudinal study of 34,439 medical experts from 1951 to 2001, commonly called the "British Physician Study." This study shows that about half of persistent cigarette smokers born in 1900-1909 were eventually killed by their addiction (calculated from the logarithm of survival probability of 35-70, 70-80, and 80-90) and about two-thirds of cigarette smokers born in the 1920s would eventually be killed by their addiction.
The health effects of smoking have been significant for the development of epidemiological science. Since the mechanism of carcinogenicity is radiomimetic or radiological, the effect is stochastic. Certain statements can be made only on the relative increased or decreased possibility of contracting certain diseases. For certain individuals, it is impossible to definitively prove a direct causal relationship between radiomimetic toxic exposures such as tobacco smoke and the following cancers; such statements can only be made at the aggregate population level. Tobacco companies have taken advantage of this philosophical objection and exploit the doubts of clinicians, who only consider individual cases, on causal relationships in the stochastic expression of toxicity as a true disease.
There have been several court cases concerning the issue that tobacco companies have examined the health effects of tobacco, but suppressed the findings or formatted them to imply diminished or absent dangers.
The term "smoker" is given to someone who is accustomed to tobacco smoking every day. This category has been the focus of most tobacco studies. However, the health effects of smoking less than a day are poorly understood. Research often takes the data of "occasional smokers" (those who never smoked daily) and grouped them with those who never smoked. A 2006 European study on smoking sometimes published findings that the risk of primary smoking-related cancers for occasional smokers was 1.24 times those who never smoked at all but the results were not statistically significant. (For a 95% confidence interval, this data shows an incidence rate ratio of 0.80 to 1.94.) (Data reduction using the Cox proportional hazards model, grouped by sex and country.) This compares with studies showing that heavy smokers has more than 50 times the incidence of cancer-related cancers.
After a smoking ban in all closed public places introduced in Scotland in March 2006, there was a 17 percent reduction in hospital admissions for acute coronary syndromes. 67% decrease occurred in non-smokers.
A study published in the journal Pediatrics refers to the danger posed by what writers call "third hand smoke" - a toxic substance that remains in areas where smoking has recently occurred.
See also
- E. Cuyler Hammond
- List of non-smoking carcinogens
References
Bibliography
External links
- Health-UE Portal - Tobacco
- Free Tobacco awareness action - How many people smoke in cars
Source of the article : Wikipedia
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