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¹ Note that when the terms “cigar(s)” or “cigars in general” are used in this report, they refer to all cigar types (filtered cigars, little cigars, cigarillos, and large/traditional cigars [which include premium cigars]). When discussing a specific cigar type, the type is noted in text.

² Note that quotations are used at the first occurrence of the term “premium” in each chapter, as there is no formally agreed upon definition of what constitutes a premium cigar, and different entities might use this term differently. See Chapter 1 for more information.

and smoking topography; see Appendix A for the full listing of research questions. Conclusions are provided throughout the chapter; a listing of all conclusions by chapter is available in the Summary.

PHYSICAL CHARACTERISTICS OF CIGARS

As noted in Chapter 1, federal regulations define a cigar as “any roll of tobacco wrapped in leaf tobacco or in any substance containing tobacco.”³ At the most basic level, the major regulatory difference between cigars and cigarettes is the wrapper; while a cigar uses a tobacco leaf or material containing tobacco (often referred to as “reconstituted tobacco” or “homogenized tobacco leaf”⁴), a cigarette has paper or a material that does not contain tobacco. Mass-produced cigarettes usually have filters, whereas most cigars do not, with a few notable exceptions like filtered cigars. Additionally, cigar filler, binder, and wrappers are predominantly air-cured and fermented tobacco, in contrast to cigarettes, which commonly use a blend of Virginia tobacco (also known as “Bright” tobacco; flue-cured), Burley tobacco (air-cured), and Turkish/oriental tobacco (sun-cured); expanded and reconstituted tobacco are also used in cigarettes (NCI, 1998; Philip Morris International, n.d.). Exceptions to this are some little cigars, which tend to use some flue-cured and/or Turkish tobacco, presumably to be more appealing to cigarette users (Delnevo and Hrywna, 2007). Cigar tobacco undergoes fermentation, which can be a multistep process that lasts months or even years for premium cigars. These differences in the manufacturing process (e.g., the fermentation process) typically result in higher nitrate levels in the tobacco and a higher (alkaline) pH of cigar smoke than cigarette smoke, which has important implications for nicotine absorption orally and by inhaling. At an alkaline pH, some of the nicotine in cigar smoke is unprotonated; this form of nicotine is readily absorbed by the oral mucosa. Alkaline smoke is also harsh and more difficult to inhale, affecting patterns of smoke inhalation into the lungs (Henningfield et al., 1999; NCI, 1998). The form of nicotine present in acidic smoke, as generally found in cigarettes, is not easily absorbed by oral mucosa, and inhalation is required for efficient nicotine absorption; it is also generally less noxious to inhale. The relationship between tobacco pH and smoke pH is complex and not fully understood, especially for premium cigars. Few studies address the pH of cigar smoke, and it can be difficult to measure. Smoke pH measurements can be affected by the measurement method and by relative humidity and

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³ 26 U.S.C. Sec. 5702a.

⁴ Reconstituted tobacco or homogenized tobacco leaf is a mixture of an adhesive with the ground remnants of tobacco that remain after manufacture. The malleable sheets of “recycled” tobacco can then be used in various tobacco products (Cigar Aficionado, n.d).

smoke density and velocity, for example (Henningfield et al., 1999; NCI, 1998). See the sections on chemistry and inhalation patterns later in this chapter for more information.

The cigar marketplace is highly diverse, including little/filtered cigars, cigarillos, large nonpremium cigars, and premium cigars (see Figure 2-1). Despite the wide variety of products, as noted in Chapter 1, no universally accepted classification system exists. The 1998 NCI monograph used four groups (see Table 1-1 in Chapter 1), which is useful because it illustrates the wide variety in the cigar marketplace. Each of these categories is described briefly below.

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⁵ The authors’ cigar classification was based on product labeling.

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⁶ Consumers and researchers may refer to Black & Mild products as cigarillos and/or filtered cigars, but they are large cigars for federal tax purposes. As Chapter 1 notes, no formal definitions exist for any cigar types (other than the large and small cigar taxation categories); therefore, the industry can name products without restriction, and consumers may have different ideas of product classification. Consequently, there is overlap in the popular brands listed for each type of cigar described in this chapter.

the other cigarette tobacco types. The pH of cigar tobacco (6.9–7.8) was higher than that of the cigarette tobacco types (4.4–7.5).

Further comparisons focused on nitrate and tobacco-specific nitrosamines. Tobacco nitrate is the precursor to nitrite in tobacco, and the latter reacts with tobacco alkaloids during curing and processing to produce tobacco-specific nitrosamines, arguably the most carcinogenic constituents occurring in relatively high quantities in unburned tobacco, including cigar tobacco. The most carcinogenic compounds among the tobacco-specific nitrosamines, based on extensive laboratory testing in animals, are N’-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), and these are considered “carcinogenic to humans” by the International Agency for Research on Cancer (IARC, 2007). NNN in particular is highly relevant to the health effects of cigars because it is a powerful oral cavity and esophageal carcinogen in rats when given in drinking water, while a mixture of NNN and NNK also produced oral and lung cancers in rats when applied in the oral cavity (Balbo et al., 2013; Hecht et al., 1986). Similar concentrations of NNN and total tobacco-specific nitrosamines (NNN, NNK, N’-nitrosoanatabine and N’-nitrosoanabasine) have been found in all tobacco types of little cigars, nonfilter cigars, filter cigarettes, and nonfilter cigarettes (NCI, 1998).

Further comparisons explored the comparative smoke profiles of cigarettes and cigars, including premium cigars. Premium and other cigar smoke have been found to deliver amounts of tar, carbon monoxide (CO), nitrogen oxides, nicotine, NNN, NNK, acrolein, acetaldehyde, benzene, isoprene, BaP and other PAH, hydrogen cyanide, metals, nitrogen oxides, and other potentially toxic constituents generally comparable to or greater than cigarettes (when expressed per gram of tobacco smoked) (NCI, 1998). However, these comparisons are complex because of the different physical characteristics of cigarettes and cigars and the different machine smoking conditions used. Additionally, smoke pH changes differentially over time for different tobacco products (see Figures 2-2 and 2-3) (Brunnemann and Hoffmann, 1974; Henningfield et al., 1999; NCI, 1998). For example, one study found that the smoke pH of cigarettes decreased from 6.0 at the third puff to 5.7 at the last. In contrast, little cigar smoke pH changed from 6.5 to 7.4 from third to last puff, and cigar smoke pH increased from 6.5 at the third puff to 8.0 at the last (Brunnemann and Hoffmann, 1974; NCI, 1998). As described, these changes are important because tobacco smoke above pH 6.0, as is generally observed in cigars, contains greater proportions of unprotonated nicotine, which affects puffing topography (the pattern of inhalation by a user) and increases oropharyngeal nicotine absorption (Henningfield et al., 1999; NCI, 1998).

risk of oral cavity cancer in users of large cigars (see Chapter 5 for more information).

Ng and colleagues (2001) developed a GC-MS method to characterize nonvolatile organic acids in cigar tobacco, quantifying them in aqueous tobacco extracts by capture on strong anion exchange disks, followed by silylation and analysis. This method was applied to analyze 18 cigars from Cuba and 31 from other countries. Their identity as premium cigars was not specified. Principal component analysis of the acid profiles of all cigars showed separation of the two groups, indicating that acid profiles, including nicotinic, succinic, malic, citric, and pyroglutamic acids, are potentially useful in authenticating Cuban cigars.

In another study of cigar tobacco constituents, levels of free plus conjugated phytosterols in (unspecified) cigar tobacco were compared to flue-cured, Oriental, Burley, and Maryland tobacco. Phytosterols are potential precursors to PAH in smoke. Total phytosterols, the sum of stigmasterol, campesterol, and β-sitotsterol and their conjugates, were similar in Burley, Maryland, and cigar tobaccos, with higher levels in flue-cured and Oriental tobaccos (Liu et al., 2008).

Pappas and colleagues (2015) developed a new analytical method to determine concentrations of 10 toxic metals in little cigar tobacco using triple quadrupole inductively coupled plasma mass spectrometry: arsenic, beryllium, cadmium, chromium, cobalt, lead, manganese, nickel, selenium, and uranium. The results indicated no significant differences in analyte levels in little cigar versus cigarette tobacco, with the exception of nickel, which was lower in little cigar tobacco.

Fresquez and colleagues (2015) developed a validated method for the high-throughput determination of mercury in tobacco and mainstream smoke from little cigars. The method used a platinum trap and direct release for analysis by heating the trap in a mercury analyzer. The tobacco mercury levels were 17.9–24.9 nanogram per gram (ng/g) tobacco.

Limited data are available on the pH of premium cigar tobacco. As described above, Lawler and colleagues (2017) compared pH values and levels of nicotine in cigarette and cigar filler, including in cigars determined by the committee to be premium cigars. The range of mean pH of the large cigar filler in aqueous solution was 5.40–6.83; the range of mean filler pH of large cigars determined to be premium was 6.12–6.83. In this analysis, 73 percent (55 out of 75 brands) of the products had filler pH levels lower than 6.0. Of the 20 cigar tobacco products with the highest filler pH levels (mean pH >6), 85 percent (17) were large cigars, and 15 were determined to be premium cigars. In fact, all premium cigars had mean filler pH levels greater than 6.0. As described earlier in this chapter, alkaline pH results in more unprotonated nicotine and greater oral absorption of nicotine. However, the relationship between tobacco pH, which is more

easily measured, and smoke pH, which is more difficult to measure, is unclear (Henningfield et al., 1999; NCI, 1998). The authors found large cigars and cigarillos to have the highest mean nicotine concentrations when compared to little cigars, pipe tobacco cigars, and mini-cigarillos. The range of mean nicotine values in large cigars was 9.2–24.8 milligram per gram (mg/g) tobacco; the range of mean nicotine in those determined by the committee to be premium was 13.2–24.8 mg/g tobacco (Lawler et al., 2017). The nicotine values can be compared to the value given in the 1998 NCI monograph, 6.0–17.0 mg/g—in the same general range and extending beyond (NCI, 1998).

The committee commissioned an analysis of tobacco nicotine content in a convenience sample of premium cigars (see Appendix F). Nicotine in tobacco was analyzed using gas chromatography with nitrogen-phosphorous detector, using a modification of the CORESTA 62 method for determination of nicotine in tobacco and tobacco products by gas chromatographic analysis (CORESTA, 2020). A summary of findings is presented in Table 2-2.⁷ Overall, the analysis reveals that the average nicotine concentration was 19.91 mg/g of tobacco and varied from 8.51 to 33.26 milligrams (Yassin et al., 2021). Total nicotine content in the sample of premium cigars was 297.89 milligrams per cigar (varying from 98.62 to 629.26) (Yassin et al., 2021).

Finally, researchers quantified the levels of the tobacco-specific nitrosamines NNN and NNK in the tobacco of 60 commercial brands of little cigars (Edwards et al., 2021). The values were 1,440–12,100 ng/g tobacco for NNN and 26–2,950 ng/g tobacco for NNK. The NNN values are in the same range as that given in the 1998 NIH monograph, 2,940 ng/g. The relatively high levels of NNN and NNK are consistent with the high concentrations found in Burley tobacco, which is used in these products (Ding et al., 2008).

Although premium cigars were not the main focus of most of these studies, there is no reason to believe that the chemical profile of premium cigars would differ in important ways from those of other cigar types. They are all made from cigar tobacco (with the exception of little cigars, which can include tobacco blends [Delnevo and Hrywna, 2007]); the main concern is the tobacco and the resulting combustion, not the design of the cigar.

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⁷ A complete summary of the methods and analysis is available in the project’s public access file and upon request from the National Academies Public Access Records Office at PARO@nas.edu.

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⁸ Two smoking conditions/methods are used by studies in this chapter. The Canadian Intense Regimen (CIR) includes 2-second puff duration, 55 milliliter (mL) puff volume, and 30-second interval (Minister of Justice, 2019), while the ISO/FTC regimen includes 2-second puff duration, 35 mL puff volume, and 60-second interval (ISO, 2012).

more of all toxicants compared to little cigars; both product types delivered substantial levels of the measured toxicants.

Goel and colleagues (2018) quantified nicotine yields in the smoke of little cigars and filtered cigars (collectively called “small cigars” because of the lack of standard definitions and inconsistent classification of both products) and compared them to cigarettes. Nicotine yields in small cigars were higher under both ISO/FTC and CIR regimens than in cigarettes, but yields per puff were similar. The two types of small cigars did not differ.

In another study of carbonyls, levels of formaldehyde, acetaldehyde, acrolein, and crotonaldehyde delivery from 12 mass-market cigars were compared to those from 3R4F cigarettes (Jablonski et al., 2019). Per product, levels of acetaldehyde, acrolein, and crotonaldehyde were greater from cigar smoke than from mainstream cigarette smoke, but levels of formaldehyde were similar from both products.

Vu and colleagues (2021) determined the mainstream smoke yields of five volatile organic compounds—1,3-butadiene, acrylonitrile, benzene, isoprene, and toluene—in 60 commercial U.S. little cigars under the ISO/FTC and CIR smoking conditions. Higher yields were found under the CIR conditions. Little cigars produced higher mainstream smoke yields than cigarettes under both smoking regimens, and little cigar smoke contained higher amounts of these compounds than cigarette smoke when amounts were adjusted for the mass of tobacco.

Edwards and colleagues (2021) quantified levels of the tobacco-specific nitrosamines NNK and NNN in the smoke of 60 commercial little cigars using the ISO/FTC and CIR smoking conditions. NNK and NNN by the ISO nonintense smoking regimen were 89–879 and 200–1,540 ng/cigar, respectively, and 138–1570 and 445–2,780 ng/cigar under the CIR regimen. The average transfer of NNN from tobacco filler to mainstream smoke of little cigars was 10–18 percent, depending on the regimen, while that of NNK was 37–51 percent. Mainstream smoke yields of NNK and NNN from little cigars were 3–5 times higher than in commercial cigarettes.

Summary and Conclusions

In summary, vast amounts of data, much of it recent, exist on toxic and carcinogenic constituents of cigar tobacco and smoke demonstrating that all analyzed toxicant levels are similar or higher than those found in cigarette tobacco and smoke, when compared per unit of tobacco. These data clearly demonstrate that cigars could be as dangerous as or more dangerous than cigarettes, with respect to toxicant and carcinogen exposure per unit consumed. Despite only limited data on premium cigars, it is reasonable to expect that the results of analyses of tobacco and smoke

would not substantially differ from those of the products presented here because premium cigars’ tobacco and pyrolysis conditions are similar to those of other cigars. Thus, based on laboratory studies using validated analytical methods and a variety of smoking conditions, including human smoking topography conditions, the available data demonstrate that exposure of premium cigar users to toxic and carcinogenic constituents of smoke will be qualitatively similar to the exposure of users to constituents of other combustible tobacco products. The relationship between tobacco pH and smoke pH remains unclear, and smoke analysis in general can be challenging. However, two laboratory studies have shown cigar smoke pH becoming more alkaline from early to last puffs, which would result in more unprotonated nicotine and therefore more oral nicotine absorption.

Conclusion 2-1: There is conclusive evidence that the addictive, toxic, and carcinogenic constituents of cigar tobacco in general are the same as those present in cigarette tobacco. There is strongly suggestive evidence that constituents of premium cigar tobacco are similar to constituents of other cigars because all tobacco contains nicotine, carcinogenic tobacco-specific nitrosamines, metals, and precursors to toxic and carcinogenic compounds formed during the combustion process.

Conclusion 2-2: There is conclusive evidence that the toxicants and carcinogens in cigar smoke in general are qualitatively the same as those in cigarette smoke. There is no reason to believe that toxicants and carcinogens in premium cigar smoke are any different from those in other types of cigars. Additionally, it is likely that the total toxic and carcinogenic constituent yields will increase with the mass of tobacco filler in the cigar.

Conclusion 2-3: There is strongly suggestive evidence that there is a wide variety of pH levels of tobacco used in cigars overall; however, higher pH has been noted in premium cigar tobacco than for other cigar types. While there is insufficient evidence on the pH of premium cigar smoke, the pH of large cigar smoke is generally higher than cigarette smoke, which can decrease depth of inhalation and increase nicotine absorption through the oral mucosa. There is insufficient evidence on the relationship between the pH of premium cigar tobacco and smoke.

BIOMARKERS

The previous section reviewed recent studies on potentially toxic and carcinogenic substances in cigar tobacco filler and smoke. The smoke concentrations were determined by machine measurements, which can be technically difficult, particularly for large cigars. Biomarkers of exposure,

substances detected in the urine, blood, saliva, and other body fluids, can potentially provide important information on human uptake and exposure under realistic conditions of product use. The following studies quantified various biomarkers in cigar users.

The tobacco alkaloids nicotine, anabasine, anatabine, nornicotine, and cotinine were quantified in the urine of subjects who smoked small cigars (Jacob et al., 1999). Levels were compared to those in the urine of users of cigarettes, smokeless tobacco, and pipes. The eight cigar users in the study used an average of five small cigars daily and excreted the lowest levels of all alkaloids except nornicotine. This was apparently the first report of systemic nicotine intake from regular cigar smoking. Cotinine levels were 1,740 µg/24 hour (h) in the cigar users compared to 3,360 µg/24 h in cigarette and 2,050 µg/24 h in smokeless tobacco users.

McDonald and colleagues (2002) measured inhalation of smoke from a “standard-sized” cigar using ^99mTc-labeled sulfur colloid particles. There were 24 male volunteers; all had smoked cigars previously, and half were current or past regular cigarette users, while the other half had no history of cigarette smoking. Researchers devised a cigar holder allowing the smoke drawn from a standard-sized cigar to mix with the ^99mTc-sulfur colloid aerosol particles along a plastic tube. A designed mouthpiece allowed each participant to inhale the mixed aerosol and smoke; imaging was performed after each subject smoked in the usual way for approximately 2 minutes in conjunction with the aerosol. Lung ventilation scanning was performed to assess inhalation. All subjects inhaled the cigar smoke to varying degrees, independent of whether they were also current or past cigarette users or exclusive cigar users.

The 1999–2012 National Health and Nutrition Examination Survey (NHANES) reported biomarkers of exposure among U.S. cigar users (Chen et al., 2014). After adjustment for age, sex, race and ethnicity, education, and body mass index, primary cigar users (those who smoked less than 100 cigarettes in their lives) had 138 times higher serum cotinine concentrations (6.2 ng/mL versus 0.045 ng/mL) and 18.9 times higher urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) concentrations (19.1 picogram [pg]/mg creatinine versus 1.01 pg/mg creatinine) than nontobacco users. Cotinine is the main metabolite of nicotine, and NNAL is a metabolite of the tobacco-specific lung carcinogen NNK. This group also had higher blood cadmium and lead concentrations than nontobacco users. Similar results for serum cotinine, urinary NNAL, and blood cadmium and lead concentrations were observed in comparing secondary cigar users (who had smoked more than 100 cigarettes in their lifetime but were not currently doing so) to nontobacco users. Primary and secondary cigar users had significantly lower serum cotinine (geometric mean cotinine concentrations: 6.2 ng/mL and 24.2 ng/mL for

primary and secondary cigar users and 131.4 ng/mL for current cigarette-only users) and urinary NNAL concentrations than current cigarette-only users (19.1 pg/mg creatinine, 78.6 pg/mg creatinine, and 215.4 pg/mg creatinine, respectively).

Rosenberry and colleagues (2018) examined levels of plasma nicotine and exhaled CO in dual users who were randomized to smoke their own brand of cigarettes or a study-provided large cigar (Phillies Blunt; not a premium cigar). Both products significantly increased plasma nicotine and exhaled CO and significantly reduced the reported urge to smoke. They concluded that such dual users alter their smoking patterns so that they are exposed to similar levels of nicotine from both products and that the results challenge the idea that cigar smoking is less toxic than cigarette smoking.

Pickworth and colleagues (2017b) examined smoking topography and toxicant exposure (plasma nicotine and exhaled CO) in three groups of study participants who smoked both cigarettes and filtered little cigars, cigarillos, or large cigars (Phillies Blunt). All products resulted in similar plasma nicotine boost, but cigarillos and large cigars resulted in greater exhaled CO. These results indicate that biomarker data from cigar types can be quite different.

Koszowski and colleagues (2017) studied biomarkers in two groups of dual users who smoked their usual brand of cigarette and an unflavored little cigar or a cigarillo. The authors found significant differences in measures of puff topography, plasma nicotine, and exhaled CO after all three. Smoke deliveries, as determined by machine smoking under conditions that replicate human smoking, were similar for all three.

Pickworth and colleagues (2017a) studied smoking patterns and toxicant exposure after smoking a little cigar and a cigarette in dual users of these products. Plasma nicotine and exhaled CO increases were essentially identical after cigarette or little cigar smoking.

Claus and colleagues (2018) examined factors related to cigar smoking, including biomarkers of exposure in current exclusive cigar users. Adult exclusive cigar users (N = 77, aged 22–77 years, 16 female) were recruited and smoked their own brand product ad libitum for up to 1 hour; biomarkers of exposure, dependence symptoms, and smoking topography were assessed. The study design separated the groups into small (3 grams) and large (>3 grams) cigar users. The first group was subdivided into small cigars and cigarillos. Exclusive cigar users who smoked at least one cigar per week had measurable and variable urinary cotinine and total NNAL concentrations (see Table 2-3). Upon smoking a single cigar, plasma nicotine levels increased significantly overall and within each group (see Figure 2-4). Exhaled CO levels significantly increased following cigar smoking in all groups, including self-reporting noninhalers.

ated with cigar smoke increases with frequency and intensity of smoking and the extent of inhalation (see Chapter 5).

Studies have shown that small cigars are often smoked and inhaled similarly to cigarettes (Pickworth et al., 2017a,b). However, determining how users puff on premium cigars and how deeply they inhale is challenging for many reasons. Unlike cigarette consumption, in which users typically light, puff rather consistently, and finish a cigarette in a single session, cigar users puff differently, take much longer to consume the product, and may not smoke the entire cigar in a single session. If so, the cigar is relit, and more of it is consumed. Another important challenge in measuring the puffing behavior of premium cigar users is the lack of commercially available instruments that can be used in research studies (Watson, 2021). Optimally, puffing behavior would be captured in natural settings that premium cigar smokers usually frequent. Puffing topography monitors would also be portable and ideally would not change the way a smoker usually uses a premium cigar. Most off-the-shelf commercial smoking topography instrumentation and hardware are designed for conventional cigarette research and need to be modified to accommodate cigars (Koszowski et al., 2017). The physical characteristics of cigarettes are consistent, unlike large cigars, which vary markedly in size and thus make standardization of measurements difficult (see the section at the beginning of this chapter and Appendix F for more information on variation in characteristics). Finally, alternative approaches to studying puffing topography, including direct observation by trained observers and video recordings, have not been commonly used to analyze inhalation patterns of premium cigar users. Although these methods minimize external influence on smoking characteristics, they cannot measure puff volume, an important index of smoke constituent intake (Blank et al., 2009).

Common measures of puffing topography include the number of puffs; the puff volume, duration, and velocity; interpuff interval; and time to smoke. Puffing topography is an index of toxicant exposure in cigarette smoking (Lee et al., 2003), making it an important measurement to understand the use behaviors of and toxicant exposure from large cigar smoking. A limited number of studies examine the smoking topography of large cigar users and the toxicant delivery from mainstream cigar smoke. The results of two clinical trials presented to the committee by Dr. Bartosz Koszowski are discussed next (Koszowski, 2021).

The first study was a published paper comparing large cigar and cigarette smoking use patterns, smoking topography, and toxicant exposure (Rosenberry et al., 2018). Dual users (n = 17, the majority of whom were men [n = 16] and African American [n = 13]) who smoked any brand of large cigar (≥1 per week) and cigarettes (≥10/day) were recruited.

In two laboratory sessions, they smoked ad libitum either their usual cigarette brand or a study-provided large cigar (Phillies Blunt). The order of tobacco products was randomized. The authors measured smoking topography in each session and collected plasma nicotine and exhaled CO before and after smoking.

Large cigars were smoked differently than cigarettes (Rosenberry et al., 2018). Participants smoked on average 1.49 grams of cigar, which was about 23 percent of the total weight. Interpuff interval was significantly shorter in large cigar smoking, while the number of puffs, puff volume, puff velocity, and time to smoke were significantly larger. According to the authors, these differences were in part due to the greater size of the large cigar than the cigarette (Rosenberry et al., 2018). However, cigar smoking had significant differences even among variables not reliant on product size (e.g., individual puff volume, puff velocity, and interpuff intervals), suggesting that the large cigars were smoked more vigorously (see Table 2-5).

Figure 2-5 illustrates an assessment of the temporal pattern of topography. The average of the first three and last three puffs found puff duration was significantly longer and interpuff interval was significantly shorter in the first three puffs for both products. Puff volume was greater

in the first three puffs for large cigars but similar for cigarettes (Rosenberry et al., 2018).

The study also found that both products significantly increased plasma nicotine and CO (see Table 2-6) (Rosenberry et al., 2018); the immediate increase implies significant large cigar smoke inhalation.

Overall, the study suggests that dual users of large cigars and cigarettes adapt their puffing behavior so that they are exposed to similar levels of nicotine from both products (Rosenberry et al., 2018). A similar smoking pattern and exposure profile was also found in another study of dual users of cigarillos and cigarettes who inhaled smoke from both in the same way, thus subjecting themselves to considerable amounts of nicotine and other smoke components (Koszowski et al., 2015). The authors concluded that, among dual users of large cigars and conventional cigarettes, exposure to smoke from large cigars may lead to or sustain nicotine addiction and produce health risks similar to those of cigarette smoking (Rosenberry et al., 2018). Lung cancer studies have elaborated on arguments about the effects of inhalation intensity and pattern on cancer development (see Chapter 5) (Doll and Peto, 1976; IARC, 2004).

The second study presented to the committee (unpublished) was a single-center, randomized, single-blinded, crossover trial that included 36 adult users of small (n = 18) and large (n = 18) cigars (Koszowski, 2021). It was designed to evaluate the relationship between tobacco pH, salivary

pH, and nicotine exposure in noninhaling cigar smokers. Assignment into study groups was based on participant report of the type of cigars they smoked and confirmation of the cigar size when participants brought their product to the laboratory for the in-person screening visit. An important methodological consideration was to limit cigar smoke exposure to buccal tissue—largely the mouth and upper pharynx—so participants complied with specific instructions given before and during the directed smoking sessions not to inhale. Two brands of large cigars were used: Dutch Master’s Palma (pH = 6.30) and White Owl NY Ranger (pH = 6.72). All participants in the large cigar group were male; the mean age was 46.1 years (range 22–64 years). Fifty percent of participants in the large cigar group identified as white. Large cigar participants reported using their products for a mean of 8.3 years and smoked an average of 16.5 cigars in the past 30 days. Only a few participants had measurable post-smoking nicotine concentrations in plasma. Most of the nicotine concentrations were undetectable by methods used in the study, but even when plasma nicotine could be quantified, the measured increases were small. Overall, this study suggests that exposure to nicotine among cigar users who smoked large cigars with acidic pH (<7.0) and did not inhale was minimal. This finding is consistent with a study by Gori and colleagues (1986), which found virtually no intake of nicotine through the buccal mucosa from cigarette smoke if it is kept in the mouth only and is not inhaled. It should be emphasized that the Koszowski (2021) study cited above did not include any large cigars with alkaline pH (>7.0). Since increased pH of smokeless tobacco has been shown to enhance nicotine absorption through buccal mucosa (Tomar and Henningfield, 1997), it is reasonably expected that increased alkalinity of a premium cigar could also promote oral nicotine absorption, even if emitted smoke is not inhaled.

The observation that dual users of cigars and cigarettes may be more likely to inhale deeply than exclusive users of cigars is also seen in differences in perceived level of inhalation reported by participants in the Cancer Prevention Study I of the American Cancer Society, conducted between 1959 and 1972. This was a prospective cohort study that followed more than 1 million individuals for 12 years (NCI, 1985, 1998). All users who participated self-reported levels of inhalation, using this subjective scale: none, slightly, moderately, or deeply. Figure 2-6 shows that individuals who inhale slightly or not at all made up the biggest portions of primary (never-cigarette user) and secondary cigar user rates. However, the study also revealed that secondary cigar users were more likely to report deep inhalation than primary cigar users (NCI, 1998).

Taken together, findings from these studies suggest that, compared to those who only smoke cigars, dual users of cigars and cigarettes are more prone to smoking cigars with a greater intensity, and therefore, inhaling

the smoke more deeply (Koszowski et al., 2015; NCI, 1998; Rosenberry et al., 2018; Rostron et al., 2016). Because of this tendency, dual use represents an especially harmful practice (Chang et al., 2015; Lee et al., 2012). This observation has important implications for a large group of premium cigar users. For example, in PATH Wave 4, only about one-third (33.7 percent) of current premium cigar users were never-cigarette users; 25.7 and 40.6 percent were current or former cigarette users, respectively (Jeon and Mok, 2022). See Chapter 3 for more information on co-use of premium cigars.

When assessing the emissions of various chemicals from premium cigars, it is important to understand how consumers are using them in natural settings (real-life conditions). In principle, mouth-level exposure to toxicants from premium cigars can be measured in laboratory settings. Tobacco smoke could be generated from a machine that closely mimics the puffing behavior of a human smoker. Replicated human puffing measures can be used to drive machine smoking of premium cigars for post hoc analyses of mainstream smoke components. Many commercially available smoking machines can be fully programmable to closely replicate users’ behavior such that cigar smoke can be generated in a laboratory setting.

The practical consequence of the wide variations in smoking behavior among cigar users renders standardized machine smoking paradigms (e.g., ISO/FTC or CIR) potentially inappropriate for the replication of cigar smoke for analysis of mainstream smoke constituents (Koszowski et al., 2017). Cigar testing puffing conditions developed originally in 1973 by the industry-formed International Committee for Cigar Smoke Studies and currently recommended by CORESTA require that large cigars be smoked for analytical purposes using a puff volume of 20 mL (adjusted for large cigars with diameter above 12 mm to achieve a constant airflow through cigar of 11.8 cm/second), a puff duration of 1.5 seconds, and frequency of puffing every 40 seconds (CORESTA, 2018). Those standardized protocols with fixed puff volumes, constant interpuff interval, and constant velocity may not be reflective of actual human smoking.

As highlighted, a major factor that may influence cigar puffing behavior appears to be a concurrent use of other combustible tobacco products, particularly cigarettes. However, other factors could also potentially influence depth of inhalation. For example, product size, density of tobacco filler, moisture of the product, and tip cutting technique may all influence airflow through the product (Watson, 2021). Restricting airflow could result in puffing harder. An increase or decrease in the cigar smoke pH may also lead to more changes in the sensory experience (Henningfield et al., 1999). Smoke that is perceived as harsh may be difficult to inhale,

while smoke that is smooth and pleasant tasting could be easily inhaled. Finally, flavorings and sweeteners may also make cigar smoke more palatable; see the next section in this chapter for more information.

As discussed in Chapter 5, low intensity of puffing and restricted inhalation of smoke during use of premium cigars have important implications for health risks observed in these users. Some users may think of cigars as less harmful than cigarettes because of the difference in the amount smoked and the inhalation style, including perceived “no inhalation,” of cigar smoke (Majeed et al., 2018). Several studies have found that beliefs that cigar users do not inhale appear to drive perceptions of less risk compared to conventional cigarettes (Bascombe et al., 2016; Cornacchione et al., 2016; Jarman et al., 2017; Jolly, 2008; Nyman et al., 2016). When asked about health risks, most participants in those studies indicated that they believed that cigars are not as risky as cigarettes. See Chapter 4 for more information on perceived risk.

In summary, inhalation patterns and the resulting exposure to nicotine and harmful and potentially harmful smoke constituents have not been studied directly in premium cigar users. However, based on the measurement of inhalation patterns among users of large cigars and studies that examined the effect of inhalation patterns on exposure to nicotine and toxicants from conventional cigarettes (Burling et al., 1985; Clark et al., 1998; Gori et al., 1986; Ingebrethsen, 2006; Tobin et al., 1982), the available data strongly suggest that inhalation patterns will be important determinants of exposure in premium cigar users, too. In particular, studies that examined the effect of inhalation patterns on exposure to nicotine and toxicants from conventional cigarettes suggest the significant effect of the depth of smoke inhalation. Although data from experimental studies that objectively measured puffing patterns in large cigar users who also smoke conventional cigarettes (dual users) are limited, they are consistent with self-reported inhalation patterns of cigar smokers who used to smoke cigarettes. Taken together, findings from these studies suggest that, compared to those who only smoke cigars, dual users of cigars and cigarettes are more prone to smoking cigars with a greater intensity and therefore inhaling the smoke more deeply.

Conclusion 2-5: There is strongly suggestive evidence that the inhalation patterns of cigar smokers in general significantly affect their exposure to nicotine and harmful and potentially harmful constituents. At present, the extent to which premium cigar users who do not inhale have systemic exposure to nicotine and harmful and potentially harmful constituents remains unknown. It is likely that smokers of premium cigars who concurrently smoke cigarettes or smoked cigarettes in the past inhale more smoke compared to exclusive users of premium cigars.

importance of sensory factors in maintaining behavior (Rose et al., 1985), and a body of work has attempted to dissociate the sensory and drug components of smoking (Rose, 2006; Rose et al., 1985, 1993, 2003; Westman et al., 1996).

Giovenco and colleagues (2017) conducted semistructured telephone interviews with 40 young adult U.S. cigar or cigarillo users to assess perceptions of product features and patterns of use. Most respondents smoked products with flavors infused in the tobacco and the cigarillo’s outer wrap. However, some preferred unflavored products because of the lack of chemical additives. Users were excited by the wide variety of flavors available and commonly reported trying many flavored varieties of their favorite brands. They also highlighted the enjoyable aroma of the smoke and a smoother and easier inhalation as benefits. Some former cigarette users reported that a flavored cigar was their first cigar experience and helped facilitate a shift to regular use.

Flavored little cigar and cigarillo use has been tied to smoking cannabis in a form of blunt⁹ (Delnevo et al., 2015; Giovenco et al., 2017). Sifaneck and colleagues (2005) found that flavors greatly influenced young peoples’ choice of cigars to use as blunts, as a flavored cigar wrapper can be used to mask cannabis odor or could help conceal cannabis smoking in public as a blunt in cigar form (Sifaneck et al., 2005). In the aforementioned study by Giovenco and colleagues (2017), many blunt users reported that flavors enhanced the taste of cannabis and made smoking more enjoyable, although some users disliked flavored cigars, particularly with high-quality cannabis.

See Box 2-1 for information about the regulatory implications of flavored cigars, Chapter 3 for more information on the popularity of flavored cigars, and Chapter 5 for discussion of the potential health effects of adding flavors to cigars.

CONCLUDING OBSERVATIONS

Despite the many different types of cigars in the U.S. market, including premium cigars, all cigar tobaccos contain the highly addictive compound nicotine, as well as toxicants and carcinogenic tobacco-specific nitrosamines. During smoking of all types of cigars, these compounds are transferred to the smoker along with multiple combustion products, many of which are toxic or carcinogenic. While specific data on chemical composition of premium cigar smoke are minimal, it is probable that the mixture of carcinogens and toxicants is qualitatively similar to that of other cigar types. See Chapter 5 for additional information on the health

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⁹ Defined by Delnevo and colleagues (2015) as a cigar with its tobacco filler removed and replaced with cannabis.

effects of these toxicants. The committee has added some new data on premium cigar characteristics, including weight and nicotine content, through commissioned work (see Appendix F).

Although it has been shown that the pH of tobacco products affects nicotine delivery, its effect on inhalation patterns and nicotine absorption in premium cigar users has not been studied systematically. Higher pH (more alkaline) of premium cigar smoke appears to facilitate nicotine absorption even in users who do not inhale. Data on premium cigar smoke inhalation topography are limited; however, past or concurrent users of other combustible tobacco products appear to puff more intensely on cigars compared to those users who only smoke cigars.

Methods are available for the analysis of premium cigar tobacco for hazardous and potentially hazardous compounds, but developing standardized conditions for quantitation of constituents of premium cigar smoke is a research priority; CORESTA may be well placed to develop these reproducible methods. Studies on puffing topography and systemic exposure to nicotine and toxicants from premium cigars also need to be prioritized. See Box 2-2 for more key research and measurement gaps.