Tobacco Filler Research Articles

Analysis of volatile compound metabolic profiles during the fermentation of filler tobacco leaves through integrated E-nose, GC–MS, GC-IMS, and sensory evaluation

Tobacco is an agricultural commodity with great economic significance. Producers recognize that the flavor characteristics of filler tobacco clear-out (FTLs) affect the quality of cigar tobacco items. To identify the major volatile organic compounds (VOCs) responsible for differences in FTLs, E-nose, HS-SPME-GC–MS, and HS-GC-IMS were employed for multi-dimensional analysis of nine groups of FTLs at various fermentation stages. The E-nose results indicated a progressive increase in nitrogen-oxygen compounds during fermentation. Coupled with these findings, HS-SPME-GC–MS identified 56 VOCs, and HS-GC-IMS revealed 55 VOCs in the FTLs. Principal component analysis (PCA) suggested that FTLs from various fermentation stages of the Yunxue No 39 tobacco plant exhibit significant differences. Partial least squares discriminant analysis (PLS-DA), along with the variable importance in projection (VIP) method for feature selection, pinpointed 12 VOCs as the essential unmistakable metabolites embroiled within the agrarian fermenting prepare of matured FTLs. During the fermentation process, these crucial metabolites are predominantly enriched in pathways including pyruvate metabolism, phenylalanine metabolism, as well as nicotinate and nicotinamide metabolism. The study provides insights into the differences and diversity of FTLs at agricultural fermentation stages. It offers valuable information for optimizing the quality of agricultural fermentation and guiding the directional fermentation of tobacco leaves.

Numerical Study on Heat Transfer and Release Characteristics of Key Components in Electrically Heated Tobacco Products

Electrically heated tobacco products (EHTPs) could release effective aerosol components from tobacco materials at relatively low temperatures without a burning phenomenon. It is essential to grasp the temperature distribution and release mechanism of key components in heated tobacco materials. The existing experimental studies have provided initial insights into the thermodynamic behavior of tobacco materials under various conditions. However, current numerical models are still in their early stages of development, with the majority failing to correlate heat transfer with component release. Based on this, a coupled numerical model of gas flow, heat transfer, and the release of key components in the electrically heated tobacco product is established in this study, which exhibits improvements in revealing the internal heat and mass transfer characteristics in the porous media of tobacco and is capable of evaluating the influence of component contents and product design parameters. The release rates of water, glycerol, and nicotine components are quantitatively described by the first-order Arrhenius formula, and the transport of heat and gas flow is simulated using the Navier-Stokes equation. The accuracy of the model is validated through experiments, including temperature monitoring at multiple measurement points and determination of residual contents in the tobacco substrate after each puff. The simulation results suggest that an appropriate component ratio and tobacco filler mass can enhance both the release amount and release efficiency of key components, and reducing either the diameter or length of the tobacco section can help to improve the heat transfer performance. A slower heating rate matched with longer preheating times enables the complementary release of water and glycerol components, which helps to regulate the uniformity of component content in the aerosol to some extent. This study helps to provide suggestions for the design and optimization of electrically heated tobacco products.

Nicotine, Humectants, and Tobacco-Specific Nitrosamines (TSNAs) in IQOS Heated Tobacco Products (HTPs): A Cross-Country Study.

Heated Tobacco Products (HTPs) purport to reduce exposure to tobacco-related toxicants compared to combustible cigarettes. This cross-sectional study examined the content of nicotine, two humectants (propylene glycol (PG) and vegetable glycerin (VG)), and four tobacco-specific nitrosamines (TSNAs: NNN, NNK, NAT, and NAB) in the tobacco filler of a popular HTP brand (IQOS). Non-menthol and menthol IQOS sticks were purchased from nine countries between 2017 and 2020 and were classified into two versions ("Bold" and "Light") using Philip Morris's flavor descriptors. The average nicotine concentration was 4.7 ± 0.5 mg/stick, and the highest nicotine concentration was found in products from Japan (5.1 ± 0.2 mg/stick). VG was the dominant humectant found in all sticks, with an average concentration of (31.5 ± 2.3 mg/stick). NNN, NNK, and NAT were substantially higher in the "Bold" sticks than the "Light" sticks. Significant differences between countries for TSNAs were also observed: the NAT and NAB contents were the highest in the "Light" products from Canada (192.5 ± 24.1 and 22.9 ± 1.0 ng/stick, respectively); the NNK concentration was the highest in the "Bold" products from Poland (64.8 ± 7.9 ng/stick); and the highest NNN concentrations were observed in the "Bold" products from South Africa (488.9 ± 26.7 ng/stick). As NNN and NNK are known human carcinogens, and as humectants like PG and VG can degrade into toxic carbonyl compounds upon heating, monitoring the concentration of these chemicals in HTPs is important for protecting users' health and ensuring compliance with regulations.

Integrated characterization of filler tobacco leaves: HS–SPME–GC–MS, E-nose, and microbiome analysis across different origins

This study delves into the aroma characteristics and microbial composition of filler tobacco leaves (FTLs) sourced from six distinct cigar-growing regions within Yunnan, China, following standardized fermentation. An integrated approach using gas chromatography-mass spectrometry (GC–MS), electronic nose (E-nose), and microbiome analysis was employed for comprehensive profiling. Results derived from Linear Discriminant Analysis (LDA) using E-nose data confirmed the presence of notable variability in flavor substance profiles among the FTLs from six regions. Additionally, GC–MS was used to discern disparities in volatile organic compound (VOC) distribution across FTLs from these regions, identifying 92, 81, 79, 58, 69, and 92 VOCs within each respective sample set. Significantly, 24 VOCs emerged as pivotal determinants contributing to the heterogeneity of flavor profiles among FTLs from diverse origins, as indicated by Variable Importance for the Projection (VIP) analysis. Furthermore, distinctions in free amino acid content and chemical constituents were observed across FTLs. Of noteworthy significance, solanone, isophorone, durene, (-)-alpha-terpineol, and 2,3'-bipyridine exhibited the strongest correlations with microbiome data, with fungal microorganisms exerting a more pronounced influence on metabolites, as elucidated through two-way orthogonal partial least-squares (O2PLS) modeling. These findings provide a theoretical and technical basis for accurately evaluating the synchronization of FTLs in aromas and fermentation processes, and they will enhance the quality of fermented FTLs and foster the growth of the domestic cigar tobacco industry ultimately.Graphical

Impact of More Intense Smoking Parameters and Flavor Variety on Toxicant Levels in Emissions of a Heated Tobacco Product.

IQOS HEETS are promoted as reduced-risk alternatives to cigarettes. Although some studies have investigated the chemical composition of HEETS emissions, little is known on whether toxicant levels in such emissions are affected by different puffing parameters and flavor varieties. This has important implications when assessing actual human exposure, since IQOS users develop a specific and personalized puffing behavior and may use different HEETS variants. This study measured the levels of nicotine, total particulate matter, carbonyl compounds, and tobacco-specific nitrosamines (TSNAs) in the emissions of nine differently flavored HEETS and two cigarettes (1R6F and Marlboro Red, MR). Emissions from Yellow HEETS, 1R6F, and MR were collected using the World Health Organization Intense smoking regime and four more intense smoking regimes. Yellow HEETS aerosol contained lower levels of toxicants compared to 1R6F and MR smoke. More intense smoking regimes increased carbonyl release in cigarette smoke, whereas only higher puff frequency led to lower levels of toxicants in Yellow HEETS aerosol. Some HEETS varieties exhibited higher levels of formaldehyde and TSNAs in their aerosols compared to Yellow HEETS. Puff frequency was identified as the only smoking parameter that significantly lowered the release of almost all toxicants in Yellow HEETS, whereas a combination of higher puff volume and puff duration led to increased levels of some carbonyls. Differences in toxicant levels between various commercially available HEETS have important implications when assessing their health impact, as their consumption might induce different toxicant exposure and health effects. HEETS release about half as much nicotine and substantially lower levels of toxicants compared to cigarettes. Literature data showed that puffing intensity is increased in cigarette smokers switching to HEETS, maybe in reaction to these lower nicotine levels. Our results show a differential impact of increased puff frequency, puff duration, and puff volume in the release of toxicants from HEETS. Thus, industry-independent studies on puff topography are critical to make choices for the most relevant puffing regime for heated tobacco product regulation. Regulators should consider evaluating the health impact of multiple HEETS varieties, as the tobacco filler composition significantly affects the release of certain toxicants.

Effect of glycerol concentration on levels of toxicants emissions from water-pipe tobacco smoking (WTS)

Glycerol, flavorings and sweeteners constitute approximately 70% of water-pipe tobacco smoking (WTS) mixtures. Tobacco mixture combustion produces smoke toxins (e.g. carbonyl compounds), of which the type and amount are highly dependable on tobacco mixture formula. While glycerol in tobacco mixture contribute to enhanced smoking experience, its’ combustion produces toxicants such as acrolein. According to WHO, there are no approved international upper limits regulations on WTS ingredients. This study aims to assess toxicant emission levels corresponding to increasing glycerol concentration in WTS mixtures, which may aid in developing tobacco regulations towards harm reduction.MethodsLaboratory experimental study. Using laboratory water-pipe smoking machine, levels of toxicant emissions in the smoke from WTS mixture samples containing varying glycerol concentrations were measured using High-performance Liquid Chromatography (HPLC). Smoke from 5 consecutive smoking cycles with 35 puffs each (ISO 22486 standard) was led through a trapping system as described in the Cooperation Centre for Scientific Research Relative to Tobacco (CORESTA) recommended method No. 74 (Determination of selected carbonyls in mainstream cigarette smoke by HPLC). Trapped carbonyls were then analysed by HPLC with a DAD detector.ResultsAcrolein emission is associated with glycerol addition in WTS mixture indicated by lab-made samples throughout all glycerol concentrations (10%, 20%, 40% and 60%), and brand samples with glycerol concentrations 10% to 20%. However, brand samples showed no increase in acrolein emission corresponding to the increase in glycerol concentrations from 20% to 60%.ConclusionThe effect of glycerol addition in waterpipe tobacco on acrolein emission varies between products. Tobacco fillers, additives and contents quality and other factors may affect toxicant emission levels. Therefore, regulatory recommendations towards defining upper limits of content concentrations require further investigations regarding potential confounders in acrolein emissions and health effects of market-available glycerol concentrations in waterpipe tobacco smoking.

Dosimetry in the lungs of α-particles (210Po) and β-particles (210Pb) present in the tobacco smoke of conventional cigarettes and heated tobacco products

Tobacco products contain radioactive 210Pb and 210Po which can be transferred from the filler to the mainstream smoke. When inhaled, they can contribute to the radioactive dose to the lungs and are suspected to significantly contribute to lung cancer from smoking. Currently, no data are available on the radioactive risk of the heated tobacco products (HTP). However, due to the relatively high heat involved in some of these devices, there are concerns about the volatility of polonium particles.Here we used data on the 210Po and 210Pb content in tobacco smoke along with biokinetic and dosimetric models to compute the effective dose induced by conventional smoking and by using an HTP device (PMI IQOS system). Results show that conventional smoking of one pack per day induces a dose to the lung of about 0.3 mSv/year. This dose decreases by a factor of ten (0.03 mSv/year) for the IQOS system. However, this dose reduction is not obtained by specific countermeasures but by the fact that the IQOS system heats only 15% of the tobacco filler to the target temperature of 330 °C. When heated homogeneously to 300 °C, both conventional and Heets (IQOS) cigarettes release about 80% of the 210Po from the tobacco, leading to similar doses to lungs.

Long-Term Storage Study of the Certified 1R6F Reference Cigarette.

The first certified reference cigarette, 1R6F, was produced by the Center for Tobacco Reference Products at the University of Kentucky in 2015 and certified in 2016. 1R6F reference cigarettes have been stored at -20 °C since they were manufactured. 1R6F has been widely used as a control cigarette or a monitor for nonclinical investigational purposes in tobacco product analysis and scientific research. However, there is little published data to demonstrate the stability of the 1R6F cigarette. In this paper, we report the results of a long-term storage study of the 1R6F cigarette tobacco filler and the resulting mainstream smoke. 1R6F cigarettes were stored under different conditions (room temperature, refrigerator (4 °C), and freezer (-20 °C)) for 3 years since April 2017. The constituents in the cigarette tobacco filler (oven volatiles, nicotine, N'-nitrosornicotine (NNN), and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)) and the mainstream smoke (nicotine, NNN, NNK, benzo[α]pyrene, carbon monoxide, total particulate matter) were analyzed. Some physical parameters (resistance to draw and ventilation) were also measured. Analysis of our data showed that no significant differences in these major constituents were detected after storage of the 1R6F cigarette at -20 °C for 3 years.

Identification of key volatile flavor compounds in cigar filler tobacco leaves via GC-IMS

Identification of key volatile flavor compounds in cigar filler tobacco leaves via GC-IMS

Effects of fermentation medium on cigar filler.

The addition of medium during industrial fermentation can improve the quality of cigar tobacco leaves after agricultural fermentation. In this study, the cigar filler tobacco "Brazilian Frogstrips YA14" was used as the test material to determine the contents of main chemical components in cigar tobacco leaves after fermentations with the additions of water (control group) and a medium (test group), and the changes in the community structure and abundances of bacteria on tobacco leaves during the fermentation process were analyzed. The results of the study were as follows: 1) During the fermentation process, the protein content of tobacco leaves fluctuated slightly, basically stabilized at 19%-20%. 2) Under the impact of the medium, the total content of main amino acids in tobacco leaves showed a downward trend, and the difference of which between the control group and the test group was the most obvious on the fourth day of fermentation. 3) The change trend of the content of petroleum ether extract in cigar leaves for the control group was not obvious, and the content of petroleum ether extract in the tobacco leaves for the test group decreased by 12.4% under the impact of the medium. 4) After fermentation, the relative content of saturated fatty acids for the control group and the test group all increased, while the relative content of unsaturated fatty acids all decreased. 5) After the addition of the medium, the diversity of bacteria on tobacco leaves changed significantly, the number of OTUs in tobacco leaves increased, and the bacterial community structure changed. This research indicates that after adding the medium to ferment cigar filler, the changes of bacterial community and dominant bacterial group on cigar tobacco leaves have impacts on the contents of chemical components in tobacco leaves, and the fermentation with the addition of medium has a positive effect on improving the quality of tobacco leaves.

A comparative study on the physicochemical properties of tobacco ash from lit bright cigarettes with different cut tobacco fillers

The physicochemical properties of tobacco ash under different combustion pyrolysis simulation conditions and in different areas of lit cigarettes rolling from various cut tobacco fillers were investigated using optical image, cigarette ash integrity (CAI), chromatic aberration (CA), scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDS), fourier transform infrared spectrometer (FTIR) and microscale combustion calorimeter (MCC), respectively. The study of ash appearance showed that lit cigarettes rolling from expanded cut stem (ECS) and reconstituted tobacco (RT) had lighter grey for the outer cigarette paper ash and darker color for the inner cut tobacco ash than those rolling from flue-cured tobacco (FCT) and expanded cut tobacco (ECT), respectively. Further study of CA and combustion rate indicated cigarette with ECS showed a highest burning rate and ΔL, followed in order by RT, ECT and FCT. SEM results displayed that various tobacco’s microstructures were still preserved at 450 °C, but fully broken at 750 °C and in the ash area of lit cigarettes, and then replaced by thin surface set with many particles for FCT, many connected lines coated with tiny particles for ECT, surface embedded with many rods for ECS and particle-containing surface for RT at 900 °C. EDX results illustrated that the above newly formed microstructures at 900 °C are mainly composed of O, C, Ca, Mg, K Cl, S and P, with a small amount of Fe, Al, Si, Mn and Co, of which some elements like K, S, P and Cl showed a migration into the gas phase. It can also obtained from EDX results that ECS left maximum C/O, K and Cl in the burning cone and tobacco ash area, followed in order by RT, FCT and ECT. FTIR study showed that carbonates have been produced substantially in the combustion cone for ECS, but just generated a little for FCT, ECT and RT. MCC analysis demonstrated that RT’s coke had the lowest thermal stability, while ECS’s coke began to release heat at lower temperature and ended at higher temperature in comparison with FCT and ECT. The correlation analysis showed that the ash appearance of burning cigarettes can be enhanced via a rise of K/Cl, K/S and K/(Cl+S) and a reduction of nicotine and ratio of sugar to nicotine.

A comparison of nicotine content methods to produce a UPC2-MS2 method for the analysis of nicotine and minor alkaloids in SPECTRUM nicotine research cigarettes.

Nicotine is the principal alkaloid in tobacco and has been the primary subject of scientific investigation for its pharmacological effects contributing to tobacco use, dependence, withdrawal, and physical harm. Related minor alkaloids, accounting for less than 6% of alkaloid content in tobacco leaves, may also mirror some of the same pharmacological effects. To detect such low concentrations of the minor alkaloids, tobacco product methods produced by the Cooperation Centre for Scientific Research Relative to Tobacco (CORESTA) using gas chromatography and flame ionization detection (GC-FID) have been adapted for use with gas chromatography-mass spectrometry (GC-MS). Nicotine and minor alkaloid content in SPECTRUM Nicotine Research Cigarettes (NRC) have previously been determined using GC-FID; however, the minor alkaloids were unable to be detected or quantitated. This study employed UltraPerformance Convergence Chromatography (UPC2) system coupled with tandem mass spectrometry (MS2) to determine the nicotine and minor alkaloid content in NRC tobacco products. CORESTA Recommended Methods (CRMs) were adapted for their sample preparative procedures for optimal extraction followed by detection with UPC2-MS2. These results were compared to two separate CRMs that used GC-FID and GC-MS2 as well as an alternative method with GC-MS2 detection. The GC-FID and GC-MS2 CRM preparations along with the alternative GC-MS2 were unable to detect the analytes in every NRC formulation, whereas the UPC2-MS2 extraction and detection method was able to quantify every analyte in every NRC formulation. This increased sensitivity demonstrates the utility of the UPC2-MS2 analytical method in accurately detecting and quantifying nicotine and minor alkaloids in tobacco filler.

The importance of cigarillo product characteristics among young adult cigarillo users: Differences by demographics, cigarillo use and other tobacco/substance use behaviors.

IntroductionCigar products, including cigarillos, have increased in popularity in the U.S. and are disproportionately used by young adults. Cigarillo product characteristics can influence consumer perceptions and the appeal of these characteristics can vary by subgroup. The goal of this study was to examine a) product characteristics important to young adult cigarillo users and b) differences based on demographics and cigarillo and other tobacco/substance use behaviors.MethodsIn 2016, a convenience sample of 628 past-year cigarillo users rated the importance of the following cigarillo product characteristics when choosing a cigarillo to smoke tobacco: brand, tobacco filler quality, tobacco wrap quality, flavors, price, package graphic design, and number of cigars in the pack. Differences in mean importance by demographic, cigarillo use and other tobacco/substance use characteristics were analyzed using t-tests and ANOVA tests.ResultsThe most important cigarillo product characteristics were price, quality of tobacco wrap, and flavors. The least important was graphic design of packaging. There were differences in importance by demographics and/or cigar and other tobacco/substance use behaviors for all product characteristics. In particular, pack size was rated as more important among current cigarillo users, users of foil pouches (2–3 cigarillos) or cardboard/paper boxes or other packaging styles, and current users of cigarettes, blunts and marijuana. Price was rated as more important among Hispanic/Latino and lower income smokers, and current cigarette and blunt smokers.ConclusionsFindings suggest cigarillo users prioritize different product characteristics depending on their demographics or smoking behavior. Further research is needed to examine whether various cigar-related policies, such as those that ban flavors or set minimum pack sizes, could impact sub-populations of cigarillo users differently.

Assessment of different heavy metals in cigarette filler and ash from multiple brands retailed in Saudi Arabia

Tobacco smoking is considered one of the major global health concerns due to its known carcinogenic effects on the human body. In this study, 36 samples of tobacco products were evaluated for the approximation of the heavy metal content, including chromium (Cr), cadmium (Cd), copper (Cu), iron (Fe), lead (Pb), manganese (Mn) and zinc (Zn) using the inductively coupled plasma - optical emission spectrometry (ICP-OES). The heavy metal content was evaluated in the tobacco filler, ash, and tobacco products (with and without filters). The average concentrations in filler tobacco products were 0.66 mg/kg, 0.09 mg/kg, 2.61 mg/kg, 245.55 mg/kg, 0.38 mg/kg, 3.985 mg/kg, and 1.64 mg/kg, for Cr, Cd, Cu, Fe, Pb, Mn, and Zn, respectively. Ash obtained from the combustion of different tobacco products had various toxic metals in different concentrations. Furthermore, the concentration of heavy metals in tobacco products (with and without filters) was also analyzed to evaluate the effect of filters. The results of the study showed that the number of heavy metals present, and their concentrations vary in different brands of tobacco products. Moreover, the concentrations for both Pb and Cd, the potent human carcinogens, were greater than the recommended threshold set forth by WHO and FAO.

Effect of artificial fermentation temperature and humidity on chemical composition and aroma quality of cigar filler tobacco

Effect of artificial fermentation temperature and humidity on chemical composition and aroma quality of cigar filler tobacco

Tobacco-Specific Nitrosamines in the Tobacco and Mainstream Smoke of Commercial Little Cigars

Cigars are among the broad variety of tobacco products that have not been as extensively studied and characterized as cigarettes. Small cigars wrapped in a tobacco-containing sheet, commonly referred to as little cigars, are a subcategory that are similar to conventional cigarettes with respect to dimensions, filters, and overall appearance. Tobacco-specific nitrosamines (TSNAs) are carcinogens in the tobacco used in both little cigars and cigarettes. This study uses a validated high-performance liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS) method to measure the TSNAs 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN) in the tobacco filler and the nonintense International Organization for Standardization smoking regimen, ISO 3308, and the newer ISO 20778 Cigarette Intensive (CI) smoking regimen mainstream smoke of 60 commercial little cigars. Tobacco filler NNK and NNN quantities ranged from 26 to 2950 and 1440 to 12 100 ng/g tobacco, respectively. NNK and NNN by the ISO nonintense smoking regimen ranged from 89 to 879 and 200 to 1540 ng/cigar, respectively; by the CI regimen, NNK and NNN ranged from 138 to 1570 and 445 to 2780 ng/cigar, respectively. The average transfer (%) for NNK and NNN from tobacco filler to mainstream smoke was 24% and 36% by the ISO nonintense and CI smoking regimens, respectively. By the ISO nonintense and CI smoking regimens, mainstream smoke NNK and NNN yields showed a moderate to strong correlation (ISO nonintense, R2 = 0.60-0.68, p < 0.0001; CI, R2 = 0.78-0.81, p < 0.0001) with tobacco filler NNK and NNN quantities. In addition, the mainstream smoke NNK and NNN yields of little cigars were determined to be 3- to 5-fold higher compared to previously tested commercial cigarettes. The mainstream smoke NNK and NNN yields have wide variation among commercial little cigars and suggest that, despite design similarities to cigarettes, machine-smoke yields of carcinogenic TSNAs are higher in little cigars.

Analysis of Pyrolysis Characteristics and Kinetics of Cigar Tobacco and Flue-Cured Tobacco by TG-FTIR

Summary Investigation of the detailed pyrolysis characteristics of tobacco raw materials is important for the understanding of product design and consumption. In this work, pyrolysis characteristics and kinetic models of cigar filler tobacco (CFT), cigar wrapper tobacco (CWT), and flue-cured tobacco (FCT) were investigated by using a thermogravimetric analyzer coupled with Fourier-transform infrared spectroscopy (TG-FTIR). The pyrolysis of different tobacco samples could be divided into four stages based on the derivative thermogravimetric analysis (DTG) curves. Flue-cured tobacco underwent a marked decomposition process at lower temperatures (about 200 °C), while the thermal decomposition of cigar tobacco occurs at higher temperatures. During the pyrolysis process, evolved gases including H2O, CO2, CH4, CO, carbonyls, alcohols, phenols and aromatic compounds were detected by FTIR. CWT released more CO2 than CFT, while the amount of CO2, CH4, CO and aromatic compounds released by flue-cured tobacco was lower than that of cigar tobacco. The pyrolysis kinetics of tobacco leaves were further analyzed and compared through the isoconversional FWO (Flynn-Wall-Ozawa) and KAS (Kissinger-Akahira-Sunose) methods. The activation energy of FCT (from 100.1 kJ mol−1 to 192.1 kJ mol−1) was lower than that of CFT (from 207.36 kJ mol−1 to 319.28 kJ mol−1) and CWT (from 160.40 kJ mol−1 to 260.45 kJ mol−1). The thermal decomposition kinetics of different tobaccos were analyzed by Málek and Coats-Redfern methods.

Levels of Chemical Toxicants in Waterpipe Tobacco and Waterpipe Charcoal Solid Waste.

This work provides insights on waterpipe tobacco and waterpipe charcoal as potential sources of environmental toxicants. Selected harmful and potentially harmful constituents (HPHCs) from ten U.S. commercial waterpipe tobacco filler products (before and after electric heating) and five waterpipe charcoal products (before and after burning) were investigated. The differences in quantities of HPHCs between the evaluated products appear to be affected by raw material properties and/or the manufacturing processes involved in product production. Trace metal quantities in waterpipe tobacco and charcoal products were observed after heating or burning conditions compared to unheated or unburned conditions, which could impact the environment through the generation of toxic tobacco product waste. This study demonstrates that waterpipe tobacco and waterpipe charcoal contain substantial quantities of benzo[a]pyrene (B[a]P) and trace metals (i.e., selenium, arsenic, cadmium, chromium, cobalt, lead, nickel) before use and that extensive and varied changes in trace metal quantities take place as a result of heating, and more studies are needed to estimate the magnitude of the environmental impact of waterpipe tobacco use.

Characterizing the Transport of Aluminum-, Silicon- and Titanium-Containing Particles and Nanoparticles in Mainstream Tobacco Smoke.

The most commonly observed forms of aluminum, silicon and titanium in tobacco products are aluminum silicates (e.g., kaolin), silica and titanium(IV) oxide. These compounds are neither water soluble nor volatile at cigarette combustion temperatures. Rather, they are transported in mainstream tobacco smoke as particles after being freed by combustion from the tobacco filler and can induce pulmonary inflammation when inhaled. Aluminum silicate particles are the most frequently observed particles in the pulmonary macrophages of smokers and have become known as 'smokers' inclusions'. A relatively new technique, single particle triple quadrupole inductively coupled plasma-mass spectrometry was used to analyze aluminum-, silicon- and titanium-containing particle deliveries in cigarette and little cigar mainstream tobacco smoke, and to collect information on solid inorganic particles. The mass concentration of aluminum-containing particles transmitted in mainstream smoke was low (0.89-0.56 ng/cigarette), which was not surprising because aluminum silicates are not volatile. Although the collective masses (ng/cigarette) of aluminum-, silicon- and titanium-containing particles under 100 nm diameter transported in mainstream smoke were low, an abundance of 'ultrafine' particles (particles < 100 nm or nanoparticles) was observed. Limitations of the particle background equivalent diameter (the smallest detectable particle size (MassHunter 4.5 Software) due to the environmentally ubiquitous silicon background restricted the determination of silica nanoparticles, but silica particles slightly below 200 nm diameter were consistently detected. Aluminum- and titanium-containing nanoparticles were observed in all cigarette and little cigar samples, with titanium(IV) oxide particle deliveries consistently fewer in number and smaller in diameter than the other two types of particles. The highest concentrations of aluminum-containing particles (as kaolin) were in the nanoparticle range with much lower concentrations extending to the larger particle sizes (>100 nm). The number and range of particle sizes determined in mainstream smoke is consistent with pulmonary deposition of aluminum silicates described by other researchers as contributing to the 'smokers' inclusions' observed in pulmonary macrophages.

Research on Behavioral Discrimination of Nicotine May Inform FDA Policy on Setting a Maximum Nicotine Content in Cigarettes.

IntroductionThe Food and Drug Administration may set a maximum nicotine content in cigarettes to minimize smoking’s addictiveness. Our recent research may indirectly support setting levels applicable to the population of dependent smokers below 1 mg/g (mg nicotine/g of tobacco filler).MethodsUsing a within-subjects design in laboratory-based studies totaling 61 nontreatment seeking adult dependent smokers, Spectrum research cigarettes with nicotine contents ranging from 1.3 to 17 mg/g (just one per session) were compared with the lowest content available, 0.4 mg/g. Identified for each participant was the smallest difference in nicotine content, or “threshold,” between cigarettes that still supported behavioral discrimination (ie, ability to objectively distinguish their difference). The next lower nicotine content cigarette, not discriminated (by definition), was labeled their “subthreshold.” Subjective perceptions and choice behavior were also assessed.ResultsThresholds varied widely among all 61 smokers but, importantly, fewer than 7% of smokers could discriminate the two lowest, 1.3 versus 0.4 mg/g nicotine, meaning more than 90% could not do so. Moreover, we found a consistent association between their nicotine discrimination threshold and their subjective perceptions and subsequent reinforcement behavior later in the session. Specifically, a participant’s discrimination threshold cigarette was also more highly rated and preferred (ie, self-administered), whereas their subthreshold cigarette was rated similarly to the 0.4 mg/g and not preferred.ConclusionsCigarette nicotine content below the threshold for perceiving nicotine’s effects (ie, its discriminability) in nearly all smokers from a no nicotine comparison is likely below 1.0 mg/g, or less than or equal to 10% of that in typical commercial cigarettes.ImplicationsCigarettes with nicotine contents able to be discriminated (threshold) are also reinforcing, and those unable to be discriminated are not reinforcing, as anticipated. Yet, research explicitly comparing cigarettes with contents below 1.0 mg/g versus no nicotine (ie, a “placebo”) is needed with larger samples. Results may confirm what nicotine content lower than 1.0 mg/g is below the threshold for discrimination (and self-administration) in the vast majority (>95%) of adult dependent smokers as well as teens beginning to smoke. Identifying that content would strongly support the Food and Drug Administration policy to establish a maximum nicotine content in cigarettes that will not maintain dependence.