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P-value column refers to results of Chi-square test for the relation between smoking and thyroid gland enlargement. Table 4. Effect of smoking on thyroid gland enlargement. Table 5. Effect of the smoking period on thyroid gland enlargement. Table 6. Effect of cigarette smoking frequency on thyroid gland enlargement.
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Table 7. Effect of Shisha smoking frequency on thyroid gland enlargement. The thyroid gland controls almost all of the metabolic processes in the body. The most common thyroid disorder involves abnormal production of thyroid hormones. Hyperthyroidism means too much of thyroid hormone, on the other hand, insufficient hormone production leads to hypothyroidism.
The results of this study revealed that the percentage of randomly selected cases was higher in the male than the female cases i. Most of the cases i. Less frequency of cases was in the age group above 60 years old which was 12 cases. The other age groups come close in the number of cases were between 20 to 30 cases. The vast majority of cases scanned were males i.
The age group from 50 to 60 years old was close to the age group of patient who are above 60 years old and it was The patient who are in the age groups less than 20, 30 to 40 and 40 to 50 years old see their numbers are very close together and were The age group of patient who are between 20 to 30 years old has a normal weight as shown in Figure 1. The highest percentage of smokers in different age groups found to be in the age group from 20 to 30 years The second category was the patients who are below 20 years of age The third and fourth categories were in the age group between 30 to 40 and 40 to 50 years old There were no smokers above 50 years old in the study whole sample.
The study sample was randomly chosen, but it was concentrating on 20 to 30 years old because many university students accepted the invitation and performed the scan Figure 2. The third and fourth categories were the patient were 30 - 40 and 50 - 60 years old which represent According to the different parameters demonstrating the period of smoking it was found that many smokers recently started smoking from 1 to 5 years which is 35 cases, and we report 27 cases of Shisha from the whole sample. It was also found that 21 smokers who have been smoking from 5 to 10 years and another 15 cases reported to smoke Shisha for more than 5 to 10 years and more than ten years of smoking were 12 cases of cigarette smokers and 3 cases of shisha smokers.
Accordingly, the effect of long period smoking has the least cases percentage in our study which creates a limitation which needs further investigation with expansion and focus on this category Figure 4. A larger proportion of cigarette smokers had a normal thyroid function The number of shisha smokers was too small to perform statistical tests. A lower proportion of cigarette and shisha smokers The effect of the period and frequency of smoking on thyroid gland enlargement could not be addressed due to small numbers of smokers in study subjects Tables The study findings agrees with the findings conducted by Asvold BO et al.
This work revealed that there are no direct significant values correlating smoking habit to thyroid volume or function. However, it is always recommended not smoke due to other well-known threats. Authors recommend further studies to be conducted due to limitations of smokers sample size. Endocrinology, , Thyroid, 9, JAMA, , Eye, 21, Przeglad Lekarski, 61, Przeglad Lekarski, 67, Journal of Internal Medicine, , International Journal of Epidemiology, 26, Journal of Endocrinology, , Archives of Internal Medicine, , European Journal of Endocrinology, , The concentration of smoke and the time after it leaves the cigarette can cause changes in particle size that may alter the relative amounts of certain chemicals in the gas and particle phases.
Also, specific properties of the tobacco, the physical design of the cigarette, and the machine-smoking method that is employed to generate mainstream smoke for analyes can have a significant impact on the levels of both mainstream and side-stream emissions. The tobacco leaf contains many alkaloid chemicals; nicotine is the most abundant.
Nicotine content varies, among other factors, by the leaf position on the tobacco stalk and also by the blend or leaf type used in a given cigarette or cigar Tso ; Kozlowski et al. Plants such as tobacco that are characterized by high alkaloid content often possess a natural pharmacologic defense against microorganisms, insects, and vertebrates. For example, nicotine is toxic to many insects and, for many years, has been extracted from tobacco for use as a commercial pesticide Domino Nicotine is addictive in humans because a portion of the nicotine molecule is similar to acetylcholine, an important brain neurotransmitter Brody et al.
Together, the sum of the concentrations of anatabine, anabasine, and nor-nicotine equals approximately 5 percent of the nicotine concentration Jacob et al. Many minor tobacco alkaloids are pharmacologically active in humans in one or more ways. Clark and colleagues observed that some of these alkaloids had physiological effects in a variety of animal tests. Lefevre reviewed the evidence and concluded that anabasine and nornicotine had demonstrated effects on smooth muscle fiber, blood pressure, and enzyme inhibition.
The literature on potentially addictive properties of these minor alkaloids is limited. S - -nicotine, which is present in the tobacco leaf, is structurally similar to forms of several minor alkaloids also found in the tobacco leaf, such as S - - N -methylanabasine Figure 3. Moreover, Dwoskin and colleagues reported that in the rat, anatabine, anabasine, N -methylanabasine, anabaseine, and nornicotine all release dopamine from striatal brain tissue. Overall, it is likely that some of the minor tobacco alkaloids could 1 be addictive if delivered alone at sufficiently high levels and 2 act together with nicotine during tobacco use to generate effects that are difficult to discern because nicotine levels are so much higher.
Structures of nicotine and minor alkaloid S - - N -methylanabasine in tobacco leaf. The unprotonated nicotine molecule contains two nitrogen atoms with basic properties. The unprotonated nicotine molecule can thus add one proton to form a monoprotonated species or two protons to form the diprotonated species Figure 3. The first proton added to nicotine attaches predominantly to the nitrogen on the five-membered pyrrolidine ring, because that nitrogen is significantly more basic than the nitrogen on the six-membered pyridine ring.
Although protonated nicotine is not volatile, unprotonated nicotine is volatile and is able to enter the gas phase and readily pass into lipid membranes. In water or in the droplets of particulate matter in tobacco smoke, the distribution of nicotine among its three forms depends on the pH of the solution.
Increasing acidity of the solution increases the fraction of protonated molecules; conversely, increasing basicity increases the fraction in the unprotonated free base form Figure 3. Because all forms of nicotine are highly soluble in water, all of the nicotine entering the respiratory tract from one puff of tobacco smoke easily dissolves in lung fluids and blood. However, because unprotonated nicotine from tobacco smoke particles is volatile, whereas protonated nicotine is not, a higher percentage of unprotonated nicotine in a puff results in a higher rate of nicotine deposition in the respiratory tract Pankow ; Henningfield et al.
The exact nature and effects of the increased rate of deposition depends on the chemical composition and the size of particles in the tobacco smoke, as well as topographic characteristics of smoking, such as puff size and duration and depth of inhalation. Increased rates of deposition in the respiratory tract lead to increased rates of nicotine delivery to the brain, which intensify the addictive properties of a drug Henningfield et al.
The conventional view has been that a sample of particulate matter from tobacco smoke is not usually so acidic that the diprotonated form becomes important. At pH 8, the two fractions are present in equal percentages. At any lower pH, the fraction of protonated nicotine is greater. Because a typical sample of particulate matter from tobacco smoke collected from a cigarette or cigar is mostly nonaqueous liquid, it is not possible to take conventional pH measurements to determine nicotine distribution between the monoprotonated and unprotonated forms Pankow However, it is possible to measure the concentration of unprotonated nicotine in a sample of tobacco smoke particulate c p ,u , because that level produces a directly proportional concentration of unprotonated nicotine in the gas phase, which is measurable Pankow et al.
Some researchers have suggested that the irritation and harshness of smoke at higher pH makes it harder for smokers to inhale this smoke into the lungs Brunnemann and Hoffmann As already noted, nicotine itself is a base. The natural acids in tobacco smoke e. The natural bases e. Variability in the acid-base nature of commercially available tobacco leaf is considerable. Simple adjustment of the tobacco blend can therefore produce a considerable range of acid or base content in tobacco smoke. The documents reveal that a variety of basic additives have been considered, including ammonia and ammonia precursors.
In summary, nicotine in cigarette smoke exists in either a protonated or unprotonated form, depending on a number of factors, including the presence of natural acids and bases, the tobacco blend, tip ventilation, and the use of additives. Cigarette design ensures that the smoke has enough unprotonated nicotine to rapidly transfer nicotine into the body but not so much of it as to be too harsh for the smoker to continue to smoke. N -nitrosamines are a class of chemical compounds containing a nitroso group attached to an amine nitrogen. There are two types of nitrosamines in tobacco and tobacco smoke: volatile and nonvolatile, including TSNAs Hoffmann et al.
The volatile nitrosamines include N -nitrosodimethylamine, N -nitrosoethylmethylamine, N -nitrosodiethylamine, N -nitro-sopyrrolidine, and N -nitrosomorpholine. The nonvolatile nitrosamines are 4- N -nitroso- N -methyl-amino butyric acid, N -nitrosopipecolic acid, N -nitroso-sarcosine, 3- N -nitroso- N -methylamino propionic acid, N -nitrosoproline, and N -nitrosodiethanolamine.
The levels of nitrosamines in tobacco products are higher than are those in other consumer products, such as cooked bacon and beer Hecht and Hoffmann , and smokers are exposed to higher levels of TSNAs than of the other nitrosamines Hoffmann et al. Studies have been conducted to identify precursors of nitrosamines and to determine the conditions required for their formation in tobacco. The primary intent of this research was to identify ways to reduce nitrosamine levels in tobacco and tobacco smoke.
Secondary and tertiary amines in tobacco, including the alkaloids, react with nitrosating agents to form N -nitrosamines Hecht and Hoffmann Hecht and colleagues showed that both nicotine and nornicotine can react with sodium nitrite under controlled conditions to form carcinogenic NNN and NNK , but nicotine is considered more important because of its higher level in tobacco products. TSNAs are not present at trace levels in freshly harvested tobacco, but they are predominantly formed during processing, curing, and storage Hoffmann et al.
In flue-cured tobacco, the curing conditions alter levels of nitrosamines Fisher a. When propane gas was introduced as the combustion source Fisher a , nitrogen oxides from the exhaust gases in tobacco barns reacted with alkaloids in the tobacco plant to form TSNAs. Hoffmann and colleagues Hoffmann et al. Volatile nitrosamines are found primarily in the gas phase of tobacco smoke, and TSNAs are almost exclusively found in the particulate phase Guerin Researchers suggest that about one-half of the nitrosamines in tobacco smoke are transferred unchanged from the tobacco to the smoke and that the remainder is formed from pyrosynthesis during smoking Hoffmann et al.
Other researchers have concluded that almost all TSNAs are transferred directly from the tobacco Fischer et al. It is difficult to determine whether TSNAs are pyrosynthesized or transferred intact, because the most important factors in nitrosamine formation such as concentrations of preformed TSNA in tobacco or their precursor, as well as chemical and physical processes during smoking, could affect either mechanism.
Morie and Sloan reported that the nitrate and amine content in tobacco determined the amount of N -nitrosodimethyl-amine formed in tobacco smoke. This finding has been widely duplicated by researchers looking at other nitrosamines Hecht et al. Other factors that influence nitrate concentrations in tobacco can also indirectly influence nitrosamine concentrations. Because TSNA content is strongly influenced by the use of stems that are naturally high in TSNAs in the cigarette rod, the increased use of stems leads to higher nitrosamines in the smoke Brunnemann et al.
Researchers have also found that the use of nitrogen fertilizer can contribute to the concentration of nitrosamines in tobacco and ultimately in the smoke Johnson and Rhoades ; Tso et al. Other influential factors identified were tobacco growth conditions, storage times, storage temperatures Andersen et al. Another factor contributing to nitrosamine concentrations in tobacco is the type of tobacco used Johnson and Rhoades ; Brunnemann et al. The nitrosamine concentrations in bright tobacco are between those in oriental and burley and depend on the curing practices described earlier Tso et al.
The TSNA concentrations are higher in blended cigarettes than in those made from bright tobacco, because burley is included in the blend Fischer et al. The preformed concentration of nitrosamines in tobacco leaves and stems is a major determinant of the levels in tobacco smoke Fischer et al. However, for cigarettes that have the same concentrations of nitrosamines in the tobacco, the nitrosamine levels in the smoke were largely determined by the degree of ventilation and the use of cellulose-acetate filter tips in the cigarette.
However, studies of cigarettes with different blends of tobacco have shown that tar is not an accurate measure of nitrosamine levels Fischer et al. Studies have also shown that cellulose-acetate filter tips remove both volatile nitrosamines and TSNAs Morie and Sloan ; Brunnemann et al. These findings indicate the importance of measuring TSNA levels in smoke, rather than using measured levels of tar or nicotine to predict levels of TSNAs in smoke on the basis of an average relationship between tar or nicotine and TSNAs.
Nitrosamine levels measured in the tobacco and the smoke from cigarettes that were purchased around the world vary widely because of the differences cited above. The investigators found that in mainstream smoke, NNN levels were 5. NNK levels were NATB levels were 8.
This finding suggests that the more advanced analytical methods used in these later studies yielded more accurate measures for current cigarettes than did previous measures. Ashley and colleagues compared TSNA concentrations in tobacco from Marlboro cigarettes with those in locally popular, non-U.
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For most of the countries, TSNA concentrations in the tobacco from Marlboro cigarettes were higher than those in tobacco from locally popular brands from that country. TSNA concentrations varied widely fold overall between and within brands from the same country and differed significantly from country to country. This study confirmed earlier work showing wide variations in TSNA levels in tobacco and smoke from products within a country and between countries Hecht et al. The basic findings from this study were confirmed by work from Wu and colleagues , who examined combined levels of NNN and NNK in the mainstream smoke from cigarettes from the same 13 countries and also found a wide variation in this matrix.
Identification of growing, curing, and blending practices that alter nitrosamine levels in tobacco and smoke have led researchers to agree that low TSNA levels in smoke can be achieved by using particular varieties of tobacco and carefully controlling the factors leading to formation and transfer of TSNAs from tobacco into smoke Brunnemann et al. To reduce TSNAs, tobacco curing in the United States is undergoing a transition, and nitrosamine levels may change as curing and blending practices change Counts et al.
In summary, nitrosamines are found in tobacco and tobacco smoke at high levels compared with other consumer products. The levels of these compounds, which are formed during tobacco processing, curing, and storage, can be minimized by breeding and selecting tobacco lines with lower propensity for TSNA formation, and limiting the use of nitrogen fertilizer, the levels of nitrogen oxides in the atmosphere during curing, the amount of burley tobacco in the blend, and storage times.
The impact of different practices is clearly seen by the wide global range of TSNA levels in tobacco and smoke. PAHs are chemical compounds with two or more condensed aromatic and other cyclic rings of carbon and hydrogen atoms Douben The U. Environmental Protection Agency EPA has identified 16 priority environmental PAHs on the basis of evidence that they cause or may cause cancer: acenaphthylene, acenaphthene, anthracene, benz[ a ] anthracene, benzo[ a ]pyrene B[ a ]P , benzo[ b ]fluoranthene B[ b ]F , benzo[ k ]fluoranthene B[ k ]F , benzo[ g ,h,i ] perylene, chrysene, dibenz[ a,h ]anthracene, fluoranthene, fluorene, indeno[1,2,3- cd ]pyrene, naphthalene, phenanthrene, and pyrene Figure 3.
The 16 PAHs, which have two to six fused rings and molecular weights of to , were detected in the particulate matter of tobacco smoke IARC , ; Ding et al. PAHs range from highly volatile to relatively nonvolatile, and their distribution in the particulate and gas phases of tobacco smoke varies with the boiling point Grimmer et al.
However, the gas phase contained only an estimated 1 percent of the total PAHs found in tobacco smoke. The composition of PAHs in mainstream smoke is different from that in sidestream smoke Grimmer et al. PAHs are formed by incomplete combustion of natural organic matter such as wood, petroleum, and tobacco and are found throughout the environment Evans et al. In the burning cone at the tip of the tobacco rod, various pyrolysis reactions occur to form methylidyne CH radicals that are precursors to the pyrosynthesis of PAHs. Hoffmann and Wynder were the first to show that adding nitrate to tobacco reduced B[ a ]P levels.
Other researchers also reported that the presence of nitrate in tobacco decreases B[ a ]P levels in the smoke Torikai et al. The pyrolytic conditions also favor the formation of PAHs from certain isoprenoids such as solanesol IARC , although other findings have disagreed with this assessment Torikai et al. Differences in tobacco type can affect levels of PAHs in the smoke.
Flue-cured bright or sun-cured oriental tobaccos have lower nitrate content than does air-cured burley tobacco. Pyrosynthesis of PAHs generates higher PAH levels in smoke from cigarettes made exclusively with flue-cured or sun-cured tobaccos than in smoke from cigarettes made with burley tobaccos Hoffmann and Hoffmann ; Ding et al.
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Cigarettes made from reconstituted tobacco with cellulose fiber as an additive yield significantly reduced PAH levels. Evans and colleagues measured PAHs in mainstream and sidestream smoke and found that B[ a ]P , B[ b ]F , and B[ k ]F levels are related to tar yields in cigarette smoke that result from differences in cigarette ventilation.
Ding and colleagues observed that total PAH levels in mainstream smoke from commercial cigarette brands varied from 1 to 1. In the same study, individual PAHs ranged from less than 10 ng generated per cigarette B[ k ]F to approximately ng naphthalene Ding et al. Other researchers reported levels of B[ b ]F at In four of five brands tested, B[ a ]P concentrations in cigarette tar were about 0.
Kaiserman and Rickert reported the levels of B[a]P in smoke from 35 brands of Canadian cigarettes by using the ISO method; mean levels were 3. Although B[ a ]P levels were linearly related to declared tar values, the tar values and the B[ a ]P levels did not change at the same relative rate.
In a study of PAHs in mainstream smoke from cigarettes from 14 countries, Ding and colleagues showed a significant global variation in levels. In summary, PAHs result from the burning of biologic material, so they are present in the smoke from any form of burning tobacco. Factors that can affect PAH levels in tobacco smoke include the type of tobacco and its nitrate content.
Because of divergent pyrosynthetic mechanisms, factors that increase the nitrate content of tobacco decrease PAH levels but may increase TSNA levels in cigarette smoke. However, a substantial reduction in PAH levels in cigarette smoke will be a challenge as long as tobacco smoke is generated from burning tobacco. When a cigarette is smoked, chemicals partition between the particulate and gas phases on the basis of physical properties including volatility and solubility Hoffmann and Hoffmann Complete partitioning of any chemical to the gas phase of cigarette smoke is generally limited to the gaseous products of combustion, such as the oxides of nitrogen, carbon, and sulfur, and the extremely volatile low-molecular-weight organic compounds.
There are between and volatile gases and other compounds in the gas phase Hoffmann and Hoffmann The nearly complete combustion of the cigarette tobacco filler generates an effluent stream of gaseous chemicals residing almost exclusively in the gas phase portion of mainstream cigarette smoke. These chemicals, on the basis of weight, account for most of the mainstream smoke.
In order by prevalence, these chemicals include N 2 , O 2 , CO 2 , CO, nitrogen oxides, and the sulfur-containing gaseous compounds. CO and CO 2 result from the combustion of tobacco. Other than N 2 and O 2 , CO and CO 2 are the most abundant compounds in mainstream cigarette smoke, representing nearly 15 percent of the weight of the gas phase.
CO 2 levels approximately 50 mg generated per cigarette are more abundant than are CO levels approximately 20 mg , as determined by the FTC machine-smoking method. Nitrogen oxide gases are formed by the combustion of nitrogen-containing amino acids and proteins in the tobacco leaf Hoffmann and Hoffmann Mainstream cigarette smoke contains mostly NO with traces of nitrogen dioxide NO 2 and nitrous oxide.
The formation of nitrogen oxides is amplified by combustion with nitrate salts, and the amount formed is directly related to the nitrate concentration of the tobacco leaf MacKown et al. Although fresh smoke contains little NO 2 , the aging of the smoke converts the reactive NO to NO 2 , which has an estimated half-life of 10 minutes Borland et al. These gases react with water and other components in cigarette smoke to form nitrate particles and acidic constituents.
Sulfur-containing gases result from the combustion of sulfur-containing amino acids and proteins Horton and Guerin In addition to the volatile gases, mainstream cigarette smoke contains a wide range of volatile organic compounds VOCs Counts et al. The formation of these VOCs results from the incomplete combustion of tobacco during and between puffs. The generation of VOCs, as well as the previously mentioned volatile gases, is directly related to the tar delivery of the cigarette, as evidenced by machine smoking under the FTC regimen Hoffmann and Hoffmann ; Polzin et al.
Therefore, factors altering the yield of tar e. Under certain machine-smoking conditions, the use of charcoal filters Williamson et al. The VOCs in mainstream cigarette smoke, as a result of their high biologic activity and levels, are among the most hazardous chemicals in cigarette smoke Fowles and Dybing ; IARC For example, more than one-half of the U. The roughly VOCs in the gas phase of mainstream cigarette smoke can be subclassified by structure.
Among the most significant classes are the aromatic hydrocarbons, carbonyls, aliphatic hydrocarbons, and nitriles. Although other classes of volatile compounds e. Aromatics are a class of compounds defined by their structural similarity to benzene. These compounds result from incomplete combustion of the organic matter of the cigarette, most notably sugars and cellulose Chortyk and Schlotzhauer Carbonyl compounds include the ketones and aldehydes.
These compounds are studied because of their reactivity and levels, which approach 1 mg generated per cigarette. Spincer and Chard identified formaldehyde in both the particulate and gas phases of tobacco smoke and found that much of the formaldehyde was associated with total particulate matter TPM.
These investigators determined that formaldehyde delivery was higher in smoke from bright tobacco than in that from burley tobacco. On the basis of total mass, hydrocarbons represent the largest VOC class in mainstream cigarette smoke Hoffmann and Hoffmann Both saturated hydrocarbons and olefins result from the incomplete combustion of cigarette tobacco.
The most abundant hydrocarbons in cigarette smoke are methane, ethane, and propane, which represent nearly 1 percent of the total cigarette effluent. The volatile nitriles, which include compounds such as HCN , acetonitrile, and acrylonitrile, are important because of their toxic effects. In summary, cigarette smoke is composed primarily of gaseous and volatile compounds. Thus, levels of these compounds are critical in determining the overall toxicity of tobacco smoke. Differences in the design of the cigarette can have a substantial effect on the levels determined in smoke, which makes the reproducibility of results challenging, but provides knowledge of possible mechanisms to reduce the exposure of smokers.
Their chemical properties span a wide range. These substances are found as pure metals or as metals naturally associated or chemically bound to other elements that can significantly alter the chemical properties of the metals. Although metals can be deposited on tobacco leaves from particles in the air and some fungicides and pesticides containing toxic metals have been sprayed on tobacco leaves or soils in the past Frank et al.
Soils, therefore, including any amendments to the soil, such as sludge, fertilizers, or irrigation with polluted water have been the predominant source of metals found in tobacco grown in various geographic areas Bache et al. Cadmium and lead content in tobacco and smoke have been correlated with the content in the soil in which the tobacco was grown, after adjustment for the amendments to the soil Bache et al. In addition, Rickert and Kaiserman showed that heavy metals in the air can be important.
For example, significant changes in the lead concentrations in the air between and accounted for most of the changes in lead levels in tobacco during that period. Researchers have associated the mercury content in tobacco with environmental factors and soil in geographic areas where the tobacco was grown Rickert and Kaiserman Mulchi and colleagues have also suggested that consideration of soil pH is important to understanding the relationship between metals in the soil and metals in the tobacco leaf.
Because of differences in the soil, air, and metal uptake by the tobacco plant, the metal content of tobaccos varies widely. Most metals and metalloids are not volatile at room temperature. A burning cigarette tip is hot enough to volatilize many metals into the gas phase, but by the time the smoke is inhaled or rises in a plume from the cigarette as secondhand smoke, most of the metals have condensed and moved into the particulate portion of the smoke aerosol Baker ; Chang et al.
The range of levels of toxic metals found in tobacco smoke reflects differences in cigarette manufacturing processes, ventilation, additives, concentrations in the tobacco, and the efficiency with which the metal transfers from the leaf to the smoke. The transfer rate of metals from tobacco into smoke also depends on the properties of the metal Krivan et al. Because tobacco plants easily absorb and accumulate cadmium from the soil, cadmium is found at relatively high concentrations in tobacco leaves. This accumulation, along with the high percentage of transfer from the leaves into the smoke Schneider and Krivan , yields high cadmium levels in tobacco smoke Chiba and Masironi Kalcher and colleagues developed a model for the behavior of metals in mainstream smoke and found that most of the cadmium in tobacco smoke is in the particulate phase, whereas lead is equally partitioned between the particulate and gas phases.
Cadmium levels have been reported to range from 10 to ng generated per cigarette in the particulate phase Allen and Vickroy ; Bache et al. Not surprisingly, Counts et al. This increase was also seen with other metals tested. In counterfeit cigarettes, levels of cadmium in particulate matter from mainstream smoke can be significantly higher, ranging from 40 to ng generated per cigarette, under FTC smoking conditions Pappas et al. Lead also transfers well from tobacco to smoke Schneider and Krivan ; measurements range from 18 to 83 ng generated per cigarette in the particulate phase Allen and Vickroy ; Nitsch et al.
Studies of cigarettes in the United Kingdom have documented concentrations of heavy metals in a number of counterfeit cigarette brands that were higher than those in domestic products Stephens et al. These metals included arsenic, cadmium, and lead. In counterfeit cigarettes, levels of lead in mainstream cigarette smoke can be significantly higher, ranging up to ng generated per cigarette, under FTC smoking conditions Pappas et al. Studies have also found similar levels of nickel in both phases: particulate levels range from 1.
Tobacco smoke also contains lower levels of other metals. The range of levels found in the particulate phase includes cobalt, 0. Gas phase levels depend on the volatility of the metals or metal complexes. Cobalt levels range from less than 1 to 10 ng generated per cigarette, and mercury levels range from 5. In a limited analysis, Chang and colleagues found arsenic and antimony in the gas phase but did not provide quantitative results.
Studies have identified radioactive elements in tobacco and tobacco smoke. Lead , a product of radioactive decay of radon, was found in tobacco Peres and Hiromoto and is transported at low levels in tobacco smoke Skwarzec et al. Most of the lead in tobacco smoke is the nonradioactive isotopes. Polonium, an element found only in radioactive forms, is also a product of radioactive decay of radon.
Some researchers have found polonium in tobacco Skwarzec et al. The presence of a filter and the type of filter used can alter the amount of polonium transferred into mainstream smoke; some filters remove 33 to 50 percent of the polonium from the smoke Ferri and Baratta In summary, the levels of metals in tobacco smoke are primarily a function of their content in the soil in which the tobacco is grown, added substances such as fertilizer, and the design of the cigarette.
Study findings indicate that 1 growing conditions for tobacco contribute to the levels of metals in cigarettes manufactured worldwide and 2 some counterfeit cigarettes have higher levels of metals than do domestic commercial cigarettes. This evidence has proved that tobacco-growing conditions can alter the concentrations of metals in cigarette tobacco and therefore the levels in the smoke. Aromatic amines and their derivatives are used in the preparation of dyes, pharmaceuticals, pesticides, and plastics Brougham et al. Because of their widespread use, aromatic amines are prevalent and may be found as contaminants in some color additives, paints, food colors, and leather and textile dyes and in the fumes from heating oils and fuels.
Studies that measured aromatic amines in the ambient environment detected their presence and determined concentrations in air, water, and soil Birner and Neumann ; Del Santo et al. Aromatic amines consist of at least one hydrocarbon ring and one amine-substituted ring, but these agents have diverse chemical structures. Chemically, aromatic amines act as bases and most exist as solids at room temperature. Some scientists have suggested that aromatic amines are present in unburned tobacco Schmeltz and Hoffmann and are also formed as combustion products in the particulate phase of tobacco smoke Patrianakos and Hoffmann Investigators determined levels of aromatic amines in both mainstream and sidestream smoke Hoffmann et al.
The identified compounds include aniline; 1-, 2-, 3-, 4-toluidine; 2-, 3-, 4-ethylaniline; 2,3-, 2,4-, 2,5-, 2,6-dimethylaniline; 1-, 2-naphthylamine; 2-, 3-, 4-aminobiphenyl; and 2-methylnaphthylamine. The most commonly studied compounds from this class are shown in Figure 3. Stabbert and colleagues a found that aromatic amines reside primarily in the particulate phase of smoke, except for the more volatile amines such as o -toluidine; only 3 percent of o -toluidine was found in the gas phase.
Studies have reported that sidestream smoke contains substantially higher levels of aromatic amines than does mainstream smoke, but these levels depend on the parameters for puffing the cigarette Patrianakos and Hoffmann ; Grimmer et al. For mainstream smoke, the levels of aromatic amines were reported to be to 1, ng generated per cigarette Luceri et al. More recently, one study reported the following levels of aromatic amines in mainstream cigarette smoke Counts et al.
Using the ISO regimen, these investigators determined that levels were 3 to 27 ng generated per cigarette for 1-aminonaphthalene; 2 to 17 ng for 2-aminonaphthalene; 0. These levels increased on average by approximately percent when the MDPH smoking regimen was used and by approximately percent under the CAN smoking regimen. Levels of aromatic amines in tobacco smoke are influenced by both the chemical constituents in the tobacco and the chemical and physical processes of the burning cigarette.
Levels of aromatic amines in smoke from cigarettes made with dark tobacco are higher than those in cigarettes made from light tobacco Luceri et al. For typical U. Sources of nitrogen in the tobacco also significantly influence levels of aromatic amines in tobacco smoke. Nitrate is a primary factor in altering the level of aromatic amines in tobacco smoke, and its presence is influenced by the use of nitrogen fertilizers Patrianakos and Hoffmann ; Stabbert et al.
Protein in tobacco is known to be a good source of biologic nitrogen, and studies have reported that higher nitrogen content from elevated protein in tobacco increased the yields of 2-naphthylamine and 4-aminobiphenyl Patrianakos and Hoffmann ; Torikai et al. Cigarette smoke from bright tobacco had lower aromatic amine levels than expected compared with the smoke of U. Combustion temperature is also a factor in the generation of aromatic amines in tobacco smoke, because lower temperatures yielded lower levels of aromatic amines in smoke Stabbert et al.
Other investigators have suggested that increased cellulose levels in tobacco can decrease aromatic amines in the smoke Torikai et al. In summary, it appears that the nitrogen content in tobacco, either from protein levels or use of nitrogen fertilizer, is a primary determinant of aromatic amine levels in tobacco smoke. The type of tobacco used in the cigarette filler also alters these levels in tobacco smoke. Heterocyclic amines HCAs are a class of chemical compounds that contain at least one cyclic ring and an amine-substituted ring.
HCAs act as basic compounds because of the amine functional group. HCAs can occur in food stuff, such as grilled meats, poultry, fish, and tobacco smoke Sugimura et al. HCAs are classified in two groups: one is produced by the pyrolysis of amino acids and proteins through radical reactions, and the other is generated by heating mixtures of creatinine, sugars, and amino acids Sugimura ; Murkovic The first group dominates when the pyrolysis temperature is high, whereas the second group is predominant at low temperatures commonly used to cook meat Sugimura HCAs are not found in unburned tobacco; they are present in tobacco smoke as a result of pyrolysis and are found in the particulate phase Manabe and Wada Users Online: Objective: To determine the prevalence of smoking among medical students at the medical college at King Fahad Medical City in Riyadh, and assess the association between smoking and socio-demographical factors, smoking contacts, reasons for smoking and attempts to quit.
Materials and Methods: Cross-sectional survey in which anonymous, self-administered questionnaire was used to survey the cigarette smoking habits of the first- and second-year medical students in the Faculty of Medicine, King Fahad Medical City in June Results: Overall The mean age of initiating smoking was There were significantly more males than females. The most important reasons for smoking were leisure, imitation of other people and a means of relieving psychological pressure. Reasons for not smoking were mostly health and religion-based.
Smokers tended to have friends who smoked. Contact with smokers particularly friends are the major risk factors for the initiation of the habit. Health and religious considerations are important motives for not smoking, quitting or attempting to quit. These findings can be of help in designing future intervention strategies. Almutairi Journal of Religion and Health. Almutairi Journal of Community Health. Abu Shomar,Ihab K. Al-Khatib,Hatem J. Desouky Dalia,S. Omar Mohamed,M. Nemenqani Dalal,Jabbar Jaweed,M.
Investigating the Association of Smoking with Thyroid Volume and Function
AlSwuailem,Majed K. Baldi International Journal of Adolescence and Youth. J Fam Community Med ; Materials and Methods. Table 1: Ever smoked and current smokers habit according to sociodemographical characteristics Click here to view. Table 4: Smoking contacts according to ever smoking habit Click here to view. Respiratory health consequences of environmental tobacco smoke.
Med Clin North Am ; Mortality in relation to smoking: 50 years' observations on male British doctors. Br Med J ; Mortality from cancer in relation to smoking: 50 years observations on British doctors. Br J Cancer ; Ezzati M, Lopez AD. Estimates of global mortality attributable to smoking in Lancet ; Crofton J, Simpson D. Tobacco: A global threat.
London UK : Macmillan; Tobacco or health. A global status report. Geneva: World Health Organization;