Puff Interval Research Articles

Exposure to Electronic Waterpipes Increases the Risk of Occlusive Cardiovascular Disease in C57BL/6J Mice.

It is well documented that cardiovascular disease (CVD) is the leading cause of death in the US and worldwide, with smoking being the most preventable cause. Additionally, most smokers die from thrombotic-based diseases, in which platelets play a major role. To this end, because of the proven harm of smoking, several novel tobacco products such as electronic(e)-waterpipe have been gaining popularity among different sectors of the population, partly due to their "false" safety claims. While many investigators have focused on the negative health effects of traditional cigarettes and e-cigarettes on the cardiovascular system, virtually little or nothing is known about e-waterpipes, which we investigated herein. To investigate their occlusive CVD effects, we employed a whole-body mouse exposure model of e-waterpipe vape/smoke and exposed C57BL/6J male mice (starting at 7 weeks of age) for 1 month, with the controls exposed to clean air. Exposures took place seven times a week, according to the well-known Beirut protocol, which has been employed in many studies, as it mimics real-life waterpipe exposure scenarios; specifically, 171 puffs of 530 ml volume of the e-liquid at 2.6 s puff duration and 17 s puff interval. The e-waterpipe exposed mice had shortened bleeding and occlusion times, when compared to the clean air controls, indicating a prothrombotic phenotype. As for the mechanism underlying this phenotype, we found that e-waterpipe exposed platelets exhibited enhanced agonist-triggered aggregation and dense granule secretion. Also, flow cytometry analysis of surface markers of platelet activation showed that both P-selectin and integrin GPIIb-IIIa activation were enhanced in the e-waterpipe exposed platelets, relative to the controls. Finally, platelet spreading and Akt phosphorylation were also more pronounced in the exposed mice. We document that e-waterpipe exposure does exert untoward effects in the context of thrombosis-based CVD, in part, via promoting platelet hyperreactivity.

Mechanism of cytotoxicity induced by the cigarette smoke extract (CSE) of heated tobacco products in vascular smooth muscle cells: A comparative study of the cytotoxic effects of CSE and the ferroptosis inducer, erastin

Heated tobacco products (HTPs) are marketed worldwide as less harmful alternatives to combustible cigarettes; however, their cytotoxic mechanisms in vascular smooth muscle cells are poorly understood. Ferroptosis is defined as iron-dependent cell death caused by the accumulation of lipid peroxidation products. In this study, the cytotoxic effects of nicotine- and tar-free cigarette smoke extracts (CSE) derived from three types of HTPs and the ferroptosis inducer, erastin, on vascular smooth muscle A7r5 cells were compared. Cigarette smoke from all HTPs was generated according to the following puffing regime: 55 mL, puff volume; 30 s, puff interval; 2 s, puff duration; bell-shaped, puff profile; and no blocking of the ventilation holes. Erastin and CSE decreased mitochondrial metabolic activity and increased lactate dehydrogenase leakage. The cytotoxic effects of erastin were almost completely inhibited by the radical-trapping antioxidant, UAMC-3203; iron chelator, deferoxamine mesylate (DFO); 12/15-lipoxygenase (12/15-LOX) inhibitor, baicalein; and selective 15-LOX inhibitor, ML351. In contrast, CSE-induced cell damage was partially attenuated by UAMC-3203, baicalein, and ML351 but not by DFO. These results suggest that erastin induces ferroptosis via 15-LOX-mediated iron-dependent lipid peroxidation, whereas CSE causes iron-independent cell damage via 15-LOX-mediated lipid peroxidation-dependent and -independent mechanisms.

Sensory appeal and puffing intensity of e-cigarette use: Influence of nicotine salts versus free-base nicotine in e-liquids

BackgroundIn the US, nicotine salts (with protonated nicotine instead of free-based nicotine) have been reported to lower the harshness and bitterness of e-cigarette aerosols, making it easier to inhale high levels of nicotine. This study aimed to determine whether nicotine salts also increase sensory appeal at lower concentrations (< 20mg/mL). Moreover, and novel, inhalation intensity of both types of e-liquids was compared. MethodsIn a randomized, double-blinded, within-participants design, healthy adults who use e-cigarettes (n=68) vaped tobacco-flavored e-liquids containing 12mg/mL of free-based nicotine or nicotine salt ad libitum, using their own device, during two online sessions (June-July 2021, Utrecht, The Netherlands). The sensory parameters perceived liking, nicotine intensity, harshness, and pleasantness were rated on a 100-unit visual analog scale. The intensity of use was determined by the recorded puff number, duration and interval. ResultsTest scores on appeal, harshness and puffing behavior parameters showed no significant differences between the nicotine salt and the free-base condition. The average inhalation time was 2.5seconds. Additional analyses found no significant effect of liquid order, age, gender, smoking status, vaping frequency and familiarity with nicotine salts. Significant positive correlations were found between the sensory parameters except for harshness. ConclusionsContrary to a previous study that used higher nicotine concentrations and standardized puffing conditions in a laboratory setting, we did not observe the effects of nicotine salts on sensory appeal in our real-life study paradigm. Moreover, we did not see effects on study parameters related to puffing intensity.

Effects of device settings and e-liquid characteristics on mouth-throat losses of nicotine delivered with electronic nicotine delivery systems (ENDS)

Currently it is not fully understood how the device settings and electronic liquid (e-liquid) composition, including their form of nicotine content, impact mouth and throat losses, and potentially lead to the variations in total nicotine delivery to the human lungs. An in situ size assessment method was developed for real-time measurements at the mouthpiece and outlet of a biorelevant mouth-throat to account for the dynamic nature of the aerosol. The aerosol size, temperature, and delivery through the mouth-throat replica and the exhaled aerosol between the puff intervals were measured at different wattages using various e-liquid compositions. The effects of body temperature and humidity on aerosol size and nicotine delivery were also explored to evaluate the importance of considering realistic in vivo conditions in in vitro measurements. Notably, in vitro tests with body temperature and humidity in mouth-throat model vs room conditions, resulted in larger aerosol size at the end of the throat (Dv50 = 5.83 ± 0.33 μm vs 3.05 ± 0.15 μm), significantly higher thoracic nicotine delivery (>90% vs 50–85%) potentially due to the lower exhaled amount (<10% vs 15–50%). Besides, higher VG/PG ratios resulted in significantly lower exhaled amount and higher mouth-throat nicotine deposition. One of the main outcomes of the study was finding significantly lower exhaled amount and higher thoracic nicotine delivery with nicotine salt form vs free-base. Considering body temperature and humidity also showed significant enhancement in nicotine delivery, so it is essential to account for biorelevant experimental conditions in benchtop testing.

Puffing topography and mouth level exposure of two closed-system Vype e-cigarettes

&lt;p&gt;E-cigarettes have the potential to reduce the harm caused by cigarette smoking; however, product likeability and product satisfaction are important in encouraging smokers to switch to less harmful products. Actual use studies play a key part in evaluating the reduced risk potential of tobacco and nicotine products. User’s puffing behaviour, including puff duration and sensory effects were evaluated for two types of e-cigarette device: a coil-and-wick ‘pen-type’ device (Vype ePen3), and a ceramic block-and-plate ‘pod-type’ device (Vype ePod) with 18 mg/ml nicotine e-liquid. Puffing topography was recorded for these devices with two groups (n=52 each) of adult regular vapers (age 21-64 years) following a fixed 10 puffs protocol where subjects vaped through a special holder attached to a puffing analyser. The sensory characteristics of the aerosol were evaluated using a questionnaire. Mean puff volume was significantly greater (p≤0.0001) for ePen3 than for ePod (79.8 vs 49.4 ml), while puff duration and puff interval were similar (2.13 vs 2.29 s and 8.9 vs 10.3 s, respectively). Notably, MLE to aerosol and nicotine from ePen3 and ePod were similar (3.89 vs 4.80 mg and 0.06 vs 0.07 mg respectively) despite of very different designs of the devices. Participants reported similar overall likeability and other sensory scores for ePen3 and ePod. In summary, the puffing topography attributes support the CORESTA recommended method no. 81, (CRM81) puffing regime, used for &lt;em&gt;in vitro&lt;/em&gt; and chemical analysis. The MLE to nicotine per session from both the products were lower than a typical 6 mg cigarette.&lt;/p&gt;

Machine Vaping of Electronic Cigarettes - A Comparison of Puffing Regimes#

Summary Several machine-based puffing regimes for collection of e-cigarette aerosol were evaluated with the objective of recommending one regime for standardization. The study involved a comparison of several candidate regimes for which puff volume, duration, interval, profile shape, and puff number were defined and varied. Testing was conducted at four laboratories using seven e-cigarette test products. Each participating laboratory generated and analyzed aerosol from the test products for glycerin, propylene glycol, water, and nicotine using the candidate regimes. Results were compared within each product’s data set to understand the impact of the regimes on product yield, consistency of results, and reliability of the testing equipment. Each of the regimes evaluated was determined to be fit for purpose for the range of products tested. Based on specific selection criteria, the recommended collection parameters are a square-shaped 55-mL puff of 3 s duration with a puff frequency of one puff every 30 s. Standardized reporting parameters include aerosol collected mass (ACM), puff count, and e-cigarette weight loss along with analyte yield on a per-puff basis and total-puffs basis.

The JUUL E-Cigarette Elevates the Risk of Thrombosis and Potentiates Platelet Activation.

Background:Smoking is the main preventable cause of death in the United States and worldwide and is associated with serious cardiovascular health consequences, including thrombotic diseases. Recently, electronic cigarettes (e-cigarettes) and, in particular JUUL, have attained wide popularity among smokers, nonsmokers, pregnant females, and even the youth, which is alarming. Interestingly, there is/are no information/studies regarding the effect of JUUL on cardiovascular diseases, specifically in the context of modulation of platelet activation. Thus, it is important to discern the cardiovascular disease health risks associated with JUUL.Methods and Results:We used a passive e-vape vapor inhalation system where C57BL/6J mice (10-12 weeks old) were exposed to JUUL e-cigarette vape. Menthol flavored JUUL pods containing 5% nicotine by weight were used as the e-liquid. Mice were exposed to a total of 70 puffs daily for 2 weeks; 3-second puff duration, and 25-second puff interval. The effects of JUUL relative to clean air were analyzed, on mouse platelet function in vitro (eg, aggregation) and in vivo (eg, FeCl3-induced carotid artery injury thrombosis model). Our results indicate that short-term exposure to JUUL e-cigarette causes hyperactivation of platelets and shortens the thrombus occlusion as well as hemostasis/bleeding times, relative to clean air (medians of 14 vs. 200 seconds, P < .01 and 35 vs. 295 seconds, P < .001, respectively).Conclusion:Our findings document—for the first time—that short-term exposure to the JUUL e-cigarette increases the risk of thrombotic events, in part by modulating platelet function, such as aggregation and secretion, in mice.

A Proposed Waterpipe Emissions Topography Protocol Reflecting Natural Environment User Behaviour.

Usage of waterpipes is growing in popularity around the world. Limited waterpipe natural environment topography data reduces the ability of the research community to accurately assess emissions and user exposure to toxicants. A portable ergonomic waterpipe monitor was provided to study participants to use every time they smoked their own waterpipe during a one-week monitoring period in conjunction with their own choice shisha tobacco. Users provided demographic information and logged their product use to supplement electronic monitor data. A total of 44 prospective study participants were invited to an intake appointment following an on-line pre-screening survey. Of these, 34 individuals were invited to participate in the study and data for 24 individuals who completed all aspects of the 1-week monitoring protocol is presented. 7493 puffs were observed during 74 waterpipe sessions accumulating over 48 h of waterpipe usage. The 95% CI on mean puff flow rate, duration, volume and interval are presented, yielding grand means of 243 [mL/s], 3.5 [s], 850 [mL], and 28 [s] respectively. The middle 95% of puff flow rates ranged between 62 to 408 [mL/s], durations from 0.8 to 6.8 [s], and puff volumes from 87 to 1762 [mL]. A waterpipe emissions topography protocol consisting of 13 flow conditions is proposed to reflect 93% of the observed range of puff flow rate, puff duration and puff volume with representative inter-puff interval, cumulative session time and aerosol volumes.

Effects of Model, Method of Collection, and Topography on Chemical Elements and Metals in the Aerosol of Tank-Style Electronic Cigarettes

Our purpose was to examine the effect of model, puffing topography (voltage, air-flow, puff interval), and method of collection on 19 elements/metals in aerosols from six tank-style electronic cigarettes (EC). Aerosols were collected from six brands using a cold trap or impinger and various puffing topographies. 19 elements were quantified using inductively coupled plasma optical emission spectroscopy. 16 elements/metals were present and quantified in the aerosols. The total concentrations of elements/metals ranged from 43 to 3,138 µg/L with the impinger method of collection and 226 to 6,767 µg/L with the cold trap method. The concentrations of individual elements were often similar across brands and across topographies. Some elements (e.g., zinc) were present in most aerosols, while others (e.g., cadmium, titanium, vanadium) were rarely found. Concentrations of some elements (e.g., lead) increased in aerosols as voltage/power increased. The model with fewest metal parts in the atomizer had the fewest metals in its aerosols. Most elements/metals in the aerosols have been found previously in the atomizers of EC. All tank-style aerosols had elements/metals that appeared to originate in the atomizers, and concentrations increased with increasing power. Concentrations of some elements were high enough to be a health concern.

Analysis of chemical constituents in mainstream bidi smoke

Bidi, an indigenous form of cigarette in South Asian countries, is popular because of its low cost and multi-flavored variants. Although recent studies have shown that bidi smokers suffer from various adverse health effects including cancer, research on bidi smoke composition and exposure levels is still very limited. In this research, the vapor and particulate phases of bidi were characterized using gas chromatography coupled with mass spectrometry (GC–MS) and Fourier-transform infrared spectrometry (FTIR). The amounts of nicotine, cotinine, indole, substituted phenols, substituted pyridines, and phytol found in different size fractions of the particulate matter collected using a cascade impactor were reported. Due to the low combustibility of the tendu leaf in bidi, a six-second puff interval was used to sample the smoke constituents for analysis. Significant levels of carbon monoxide, hydrogen cyanide, and hydrocarbons like ethylene, methane and 1, 3-butadiene were detected in the mainstream bidi smoke. In addition, 3-methylpyridine, cotinine, α-amyrin, and β-amyrin were also present at high levels in bidi smoke. Despite having less tobacco compared to conventional cigarette, bidi smokers are potentially exposed to significantly higher concentrations of nicotine due to the greater puffing frequency. The non-porous nature and higher moisture content of tendu leaf in bidis compared to cigarette wrapping paper led to higher levels of carbon monoxide and tar in bidi smoke compared to regular cigarette smoke. Results of this study indicate the presence of harmful and carcinogenic chemicals in the mainstream bidi smoke that could be harmful to human health.

Novel instrument to generate representative e-cigarette vapors for physicochemical particle characterization and in-vitro toxicity

The use of “electronic cigarettes” (e-cigs) has exponentially increased during the last decade. This drastic growth has been observed in smokers and never smokers, women and teenagers, with indicators for adverse effects related to nicotine, but also to e-liquid and vapor components. The aerosol characteristics depend on the e-cig features. Therefore, the introduction of many different e-cig types on the market leads to concerns regarding their potential health effects. Our study aims to develop an instrument to generate representative vapors from e-cigarette devices, characterize the physicochemical properties of the aerosols and elucidate the adverse effects of inhaled vapors on normal human airway epithelia. E-cig vapors were produced using a specially developed aerosol generation instrument mimicking user puffing behavior. Aerosol particle size distribution and concentration were characterized with a Scanning Mobility Particle Sizer. Air-liquid interface cultures of differentiated human bronchial epithelial cells were exposed to 1 puff topography, i.e. to 21 puffs of 3 s with 22-second puff intervals using the Nano-Aerosol Chamber for In-Vitro Toxicity, which simulates particle deposition in the respiratory tract. Cell morphology was evaluated by light microcopy and induction of cell death by release of lactate dehydrogenase at 4 and 24 h after aerosol exposure. Particle size in e-cig generated aerosols ranged from 20 to 430 nm and concentrations exceeded 1 × 106 particles/cm3. Deposited particle doses were 0.9–3 μg/cm2, depending on e-device type and number of puffs. A single exposure to e-cig vapors caused changes in epithelial cell shape but no massive cell death. We successfully developed an aerosol generation system to produce and deposit realistic vapors from e-cigs. The results obtained indicate that a single exposure to e-cig aerosols affects epithelial morphology and slightly increases cell death. Our interdisciplinary approach combining aerosol technology and biology allows identifying adverse effects of e-cigs to the respiratory tract in vitro.

Circadian Puffing Behavior and Topography Among E-cigarette Users.

The aim of this study was to examine puffing behavior and topography over 24 hours among regular electronic cigarette (e-cigarette) users. Twenty-four adult e-cigarette users (15 male) vaped their personal e-cigarettes ad-lib over the course of 24 hours. Participants took each puff via calibrated CReSS pocket topography monitors. We analyzed: number of puffs per day per session, mean puff volume, mean puff flow rate, mean duration of puff, and mean interval between puffs. Over 24 hours participants took on average 156.2±10.3 puffs, clustered in 10.2±7.9 puffs per puffing session with an average puff interval of 15.4±22.0 sec. A single puff lasted on average 3.0±1.2 sec, had a volume of 73.4±51.5 ml, and was taken with the average flow rate of 24.7±10.2 ml/sec. There is substantial variability among e-cigarette users in the way they puff on these devices. When e-cigarette aerosol is generated for laboratory studies, there is a need for validated puffing protocols that not only reflects the most-common pattern but also intensive puffing behaviors observed among some e-cigarette users.

Cigarette Filter Ventilation and Smoking Protocol Influence Aldehyde Smoke Yields.

The WHO study group on tobacco product regulation (TobReg) advised regulating and lowering toxicant levels in cigarette smoke. Aldehydes are one of the chemical classes on the TobReg smoke toxicants priority list. To provide insight in factors determining aldehyde yields, the levels of 12 aldehydes in mainstream cigarette smoke of 11 Dutch brands were quantified. Variations in smoking behavior and cigarette design affecting human exposure to aldehydes were studied by using four different machine testing protocols. Machine smoking was based on the International Standardization Organization (ISO) and Health Canada Intense (HCI) regime, both with and without taping the filter vents. The 11 cigarette brands differed in (i) design and blend characteristics; (ii) tar, nicotine, and carbon monoxide (TNCO) levels; (iii) popularity; and (iv) manufacturer. Cigarette smoke was trapped on a Cambridge filter pad and carboxen cartridge. After being dissolved in methanol/CS2 and derivatization with DNPH, the aldehyde yields were determined using HPLC-DAD. Using an intense smoking regime (increased puff volume, shorter puff interval) significantly increased aldehyde yields, following the pattern: ISO < ISO-taped < HCI-untaped < HCI. For all of the regimes, acetaldehyde and acrolein yields were strongly correlated (r = 0.804). The difference in TNCO and aldehyde levels between regular and highly ventilated low-TNCO cigarettes (as measured using ISO) diminished when smoking intensely; this effect is stronger when combined with taping filter vents. The highly ventilated low-TNCO brands showed six times more aldehyde production per mg nicotine for the intense smoking regimes. In conclusion, acetaldehyde and acrolein can be used as representatives for the class of volatile aldehydes for the different brands and smoking regimes. The aldehyde-to-nicotine ratio increased when highly ventilated cigarettes were smoked intensely, similar to real smokers. Thus, a smoker of highly ventilated low-TNCO cigarettes has an increased potential for higher aldehyde exposures compared to a smoker of regular cigarettes.

Effect of e-liquid flavor on electronic cigarette topography and consumption behavior in a 2-week natural environment switching study.

Electronic Nicotine Delivery Systems (ENDS) offer an alternate means to consume nicotine in a variety of flavored aerosols. Data are needed to better understand the impact of flavors on use behavior. A natural environment observational study was conducted on experienced ENDS users to measure the effect of e-liquid flavor on topography and consumption behavior. The RIT wPUMTM monitor was used to record to record the date and time and puff topography (flow rate, volume, duration) for every puff taken by N = 34 participants over the course of two weeks. All participants used tobacco flavor for one week, and either berry or menthol flavor for one week. Results provide strong evidence that flavor affects the topography behaviors of mean puff flow rate and mean puff volume, and there is insufficient evidence to support an influence of flavor on mean puff duration and mean puff interval. There was insufficient evidence, due to the low power associated with the limited number of observation days, to establish a relationship between flavor and cumulative consumption behavior. While the results indicate that an effect may be evident, additional observation days are required to establish significance.

Assessment of novel tobacco heating product THP1.0. Part 3: Comprehensive chemical characterisation of harmful and potentially harmful aerosol emissions

For a tobacco heating product (THP), which heats rather than burns tobacco, the emissions of toxicants in the aerosol were compared with those in cigarette smoke under a machine-puffing regimen of puff volume 55 ml, puff duration 2 s and puff interval 30 s. The list of toxicants included those proposed by Health Canada, the World Health Organization Study Group on Tobacco Product Regulation (TobReg), the US Food and Drug Administration and possible thermal breakdown products. In comparison to the University of Kentucky 3R4F reference cigarette the toxicant levels in the THP1.0 emissions were significantly reduced across all chemical classes. For the nine toxicants proposed by TobReg for mandated reduction in cigarette emissions, the mean reductions in THP1.0 aerosol were 90.6–99.9% per consumable with an overall average reduction of 97.1%. For the abbreviated list of harmful and potentially harmful constituents of smoke specified by the US Food and Drug Administration Tobacco Products Scientific Advisory Committee for reporting in cigarette smoke (excluding nicotine), reductions in the aerosol of THP1.0 were 84.6–99.9% per consumable with an overall average reduction of 97.5%.

Effects of Switching to the Tobacco Heating System 2.2 Menthol, Smoking Abstinence, or Continued Cigarette Smoking on Biomarkers of Exposure: A Randomized, Controlled, Open-Label, Multicenter Study in Sequential Confinement and Ambulatory Settings (Part 1).

IntroductionThe menthol Tobacco Heating System 2.2 (mTHS) is a newly developed candidate modified-risk tobacco product intended to reduce exposure to the harmful and potentially harmful constituents (HPHCs) of conventional cigarette (CC) smoke. This study examined the impact of switching to mTHS on biomarkers of exposure to HPHCs relative to menthol CCs (mCCs) and smoking abstinence (SA).MethodsIn this three-arm, parallel-group study, 160 Japanese adult smokers (23–65 years; smoking ≥10 mCCs per day) were randomized to mTHS (n = 78), mCC (n = 42), or SA (n = 40) for 5 days in confinement and 85 days in ambulatory settings. Endpoints included biomarkers of exposure to HPHCs, human puffing topography, safety, and subjective effects of smoking measures.ResultsAfter 5 days of product use, the concentrations of carboxyhemoglobin, 3-hydroxypropylmercapturic acid, monohydroxybutenyl mercapturic acid, and S-phenylmercapturic acid were 55%, 49%, 87%, and 89% lower (p < .001), respectively, in the mTHS group than in the mCC group. Other biomarkers of exposure (measured as secondary endpoints) were 50%–94% lower in the mTHS group than in the mCC group on day 5. These reductions in the mTHS group were maintained at day 90, similar to the SA group. Switching to mTHS was associated with changes in human puffing topography (shorter puff intervals and more frequent puffs). The urge-to-smoke and smoking satisfaction levels on day 90 were similar in the mTHS and the mCC groups.ConclusionSwitching from mCCs to mTHS significantly reduced exposure to HPHCs relative to continuing smoking mCCs with concentrations similar to those observed following SA in Japanese adult smokers.ImplicationsThis randomized study compared the impact of switching to a modified-risk tobacco product candidate mTHS on biomarkers of exposure to HPHCs of cigarette smoke relative to continuing smoking cigarettes or abstaining from smoking in sequential confinement and ambulatory settings. The study showed that switching to mTHS was associated with significant biomarker reductions within 5 days in confinement, these reductions being maintained throughout the ambulatory setting up to day 90. The results provide evidence that switching to mTHS reduces real-life exposure to HPHCs in adult smokers.

Emissions of Toxic Carbonyls in an Electronic Cigarette

Summary Electronic cigarettes (e-cigs) provide a smoke-free alternative for inhalation of nicotine without the vast array of toxic and carcinogenic combustion products produced by tobacco smoke. Elevated levels of toxic carbonyls may be generated during vaporisation; however, it is unclear whether that is indicative of a fault with the device or is due to the applied conditions of the test. A device, designed and built at this facility, was tested to determine the levels of selected toxic carbonyls. The reservoir was filled with approximately 960 mg of an e-liquid formulation containing 1.8% (w/v) nicotine. Devices were puffed 200 times in blocks of 40 using a standardised regime consisting of a 55 mL puff volume; 3 s puff duration; 30 s puff interval; square wave puff profile. Confirmatory testing for nicotine and total aerosol delivery resulted in mean (n = 8) values of 10 mg (RSD 12.3%) and 716 mg (RSD 11.2%), respectively. Emissions of toxic carbonyls were highly variable yet were between &lt; 0.1% and 22.9% of expected levels from a Kentucky Reference Cigarette (K3R4F) puffed 200 times under Health Canada Intense smoking conditions. It has been shown that a device built to a high specification with relatively consistent nicotine and aerosol delivery emits inconsistent levels of carbonyls. The exposure is greatly reduced when compared with lit tobacco products. However, it was observed that as the reservoirs neared depletion then emission levels were significantly higher

Electronic cigarette nicotine delivery can exceed that of combustible cigarettes: a preliminary report

IntroductionElectronic cigarettes (ECIGs) aerosolise a liquid that usually contains propylene glycol and/or vegetable glycerine, flavourants and the dependence-producing drug, nicotine, in various concentrations. This laboratory study examined the relationship between...

Relationship Between Mainstream Cigarette Smoke “Tar” and Nicotine Yields

Abstract The purpose of this research was to examine the relationship between mainstream “tar” and nicotine yields and refine the commonly used linear model with a positive intercept to incorporate non-linearity and product-toproduct differences in filler nicotine content. “Tar” and nicotine yields are examined for a wide range of cigarettes (U.S. and international) using the Cambridge filter (CF), ISO, and the more intense MDPH, and HC smoking methods. Particularly at very low machine yields, a nonlinearity is observed that can be more accurately modeled by a power law relationship, and can be further improved by incorporating the concentration of nicotine in the cigarette filler into the equation. The resultant power law relationship is the better statistical fit to the available data, avoids the physical implausibility of positive nicotine yield at zero “tar” yield and lack of dependence on filler nicotine that are inherent in the simple linear model relating nicotine yield to “tar” yield alone, and explains the nonconstancy of the “tar”-to-nicotine ratio. The relationship between “tar” and nicotine can be affected by the use of very long or very short puff intervals, and, with the same tobacco blend and the same “tar” yield, longer cigarettes tend to have a slightly higher nicotine yield than shorter cigarettes.

What Reaches the Antenna? How to Calibrate Odor Flux and Ligand-Receptor Affinities

Physiological studies on olfaction frequently ignore the airborne quantities of stimuli reaching the sensory organ. We used a gas chromatography-calibrated photoionization detector to estimate quantities released from standard Pasteur pipette stimulus cartridges during repeated puffing of 27 compounds and verified how lack of quantification could obscure olfactory sensory neuron (OSN) affinities. Chemical structure of the stimulus, solvent, dose, storage condition, puff interval, and puff number all influenced airborne quantities. A model including boiling point and lipophilicity, but excluding vapor pressure, predicted airborne quantities from stimuli in paraffin oil on filter paper. We recorded OSN responses of Drosophila melanogaster, Ips typographus, and Culex quinquefasciatus, to known quantities of airborne stimuli. These demonstrate that inferred OSN tuning width, ligand affinity, and classification can be confounded and require stimulus quantification. Additionally, proper dose-response analysis shows that Drosophila AB3A OSNs are not promiscuous, but highly specific for ethyl hexanoate, with other earlier proposed ligands 10- to 10 000-fold less potent. Finally, we reanalyzed published Drosophila OSN data (DoOR) and demonstrate substantial shifts in affinities after compensation for quantity and puff number. We conclude that consistent experimental protocols are necessary for correct OSN classification and present some simple rules that make calibration, even retroactively, readily possible.