Characteristic Human Individual Puffing Profiles Can Generate More TNCO than ISO and Health Canada Regimes on Smoking Machine When the Same Brand Is Smoked

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

INTRODUCTION

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

IMPLICATIONS

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.

Nicotine Delivery of a Menthol-Flavored Heat-not-Burn Tobacco Product During Directed Use

INTRODUCTION

IQOS was authorized by the U.S. Food and Drug Administration (FDA) as a modified-risk tobacco product. We conducted a pharmacokinetic study evaluating the nicotine delivery and subjective effects of IQOS use among current menthol cigarette smokers to better understand if IQOS is an acceptable cigarette alternative in light of the proposed menthol cigarette ban.

AIMS AND METHODS

Participants were adult smokers of >4 menthol cigarettes per day. After 14-hour nicotine abstinence, participants were provided an IQOS device and menthol heatstick to puff every 20 seconds for a total of 14 puffs. Blood samples were collected at baseline and during active use to calculate nicotine boost from baseline to peak concentration. Nicotine withdrawal symptoms were collected before and after IQOS use. In addition, a modified Product Evaluation Scale for IQOS was collected after use.

RESULTS

Participants (n = 8) were a mean age of 43.9 years, 63% were female, 88% identified as White, and they smoked a mean of 17.1 menthol cigarettes per day. After IQOS use, the mean nicotine boost obtained was 15.96 ng/mL (SD = 6.91) (range 9.31 to 30.55 ng/mL). Most (75%) participants reported enjoying use of the product "a lot" or greater and more than half (62.5%) reported reduced cigarette cravings. Most participants reported no side effects after use; however, two experienced dry mouth, three experienced dizziness, one experienced throat irritation, and one experienced headache.

CONCLUSION

We found that directed use (14 puffs) of menthol IQOS delivered a mean nicotine boost of 15.96 ng/mL which reduced craving for a cigarette. The majority of participants enjoyed use of IQOS and reported mild side effects.

IMPLICATIONS

Menthol IQOS delivered a sufficient dose of nicotine perceived as satisfying by menthol cigarette smokers and it reduced craving with mild side effects. Menthol IQOS has potential to serve as a less harmful alternative for menthol cigarette smokers. The availability of modified risk products like IQOS should be considered by FDA's Comprehensive Plan for Tobacco and Nicotine Regulation.

Aerosol Emissions from Heated Tobacco Products: A Review Focusing on Carbonyls, Analytical Methods, and Experimental Quality

We provide an extensive review of 17 independent and industry-funded studies targeting carbonyls in aerosol emissions of Heated Tobacco Products (HTPs), focusing on quality criteria based on the reproducibility of experiments, appropriate analytic methods, and puffing regimes. Most revised studies complied with these requirements, but some were unreproducible, while others failed to consider analytical variables that may have affected the results and/or produced unrealistic comparisons. We also provide a review of the literature on the physicochemical properties of heated tobacco and HTP aerosols, as well as the evaluation of HTPs by regulatory agencies, addressing various critiques of their relative safety profile. The outcomes from the revised studies and regulatory evaluations tend to agree with and converge to a general consensus that HTP aerosols expose users to significantly lower levels of toxicity than tobacco smoke.

Protecting public health and the environment: towards a general ban on cellulose acetate cigarette filters in the European Union

After the establishment of a causal relationship between tobacco use and cancer in the 1950s, cellulose acetate filters were introduced with the claim to reduce the adverse health impact of unfiltered cigarettes. Often perceived to be more pleasant and healthy, filters encouraged smoking. However, filtered cigarettes are more deeply inhaled to obtain the same nicotine demand while altered combustion releases more tobacco-specific nitrosamines. The increasing use of cigarette filter ventilation is associated with a sharp rise in lung adenocarcinomas in recent decades. While not preventing adverse health effects, a global environmental problem has been created due to the non-biodegradable filter litter, causing ecotoxicological effects and the spread of microplastics. Recently, the Belgian Superior Health Council advised policymakers to ban cigarette filters as single-use plastics at both national and European levels. This article outlines the arguments used to justify this plea (human health and environment), the expected effects of a filter ban, as well as the public reception and reactions of the tobacco industry. The specific context of the European Union is discussed including the revision of the Single-Use Plastics Directive, affording a new opportunity to ban plastic filters. This perspective article aims to fuel the momentum and cooperation among member states for this purpose.

E-cigarette puffing topography: The importance of assessing user behaviour to inform emissions testing

Analysis of the chemical composition of e-cigarette emissions is an important step in determining whether e-cigarettes offer both individual and population-level harm reduction potential. Commonly, e-cigarette emissions for chemical analysis are collected when using e-cigarettes according to standardised puffing regimens, such as those recommended by the International Organization for Standardization (ISO) or the Cooperation Centre for Scientific Research Relative to Tobacco (CORESTA). While the use of such standard puffing regimens affords a degree of uniformity between studies and are also recommended by regulatory authorities who require the submission of e-cigarette emissions data to make decisions regarding allowing a product to be commercially marketed, the standardised regimens do not necessarily reflect human puffing behaviour. This can lead to under- or over-estimating real-world emissions from e-cigarettes and inaccuracy in determining their harm reduction potential. In this review, we describe how human puffing behaviour (topography) information can be collected both in the clinical laboratory and in the real world using a variety of different methodologies. We further discuss how this information can be used to dictate e-cigarette puffing regimens for collecting emissions for chemical analyses and how this may lead to better predictions both of human yields of e-cigarette emissions constituents and of risk assessments to predict e-cigarette tobacco harm reduction potential.

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

BACKGROUND

In 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.

METHODS

In 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.

RESULTS

Test 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.

CONCLUSIONS

Contrary 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.

Electronic Cigarette Nicotine Flux, Nicotine Yield, and Particulate Matter Emissions: Impact of Device and Liquid Heterogeneity

INTRODUCTION

Electronic cigarettes (ECIGs) heat a nicotine-containing liquid to produce an inhalable aerosol. ECIG power (wattage) and liquid nicotine concentration are two factors that predict nicotine emission rate ("flux"). These factors can vary greatly across devices and users.

AIMS AND METHODS

The purpose of this study was to examine ECIG device and liquid heterogeneity in "real world" settings and the association with predicted nicotine flux, nicotine yield, and total particulate matter (TPM) emissions. Past 30-day ECIG users (n = 84; mean age = 23.8 years [SD = 9.6]) reported device and liquid characteristics. Device power was measured via multimeter, device display screens, or obtained via labeling. Liquid nicotine concentration was obtained via labeling or through chemical analysis. Predicted nicotine flux, nicotine yield, and TPM associated with 10 4-second puffs were calculated for participants' primary devices.

RESULTS

Participants' primary devices were box mods (42.9%), disposable vapes (20.2%), and pod mods (36.9%). Most participants (65.5%) reported not knowing their primary device wattage. Rebuildable/box mods had the greatest power range (11.1-120.0 W); pod mod power also varied considerably (4.1-21.7 W). Unlike device wattage, most participants (95.2%) reported knowing their liquid nicotine concentration, which ranged from 3.0 to 86.9 mg/ml (M = 36.0, SD = 29.3). Predicted nicotine flux varied greatly across products (range =12.0-160.1 μg/s, M = 85.6 μg/s, SD = 34.3). Box mods had the greatest variability in wattage and predicted nicotine flux, nicotine yield, and TPM yield.

CONCLUSIONS

ECIG device and liquid heterogeneity influence nicotine and other toxicant emissions. Better measurement of ECIG device and liquid characteristics is needed to understand nicotine and toxicant emissions and to inform regulatory policy.

IMPLICATIONS

ECIG device and liquid heterogeneity cause great variability in nicotine flux and toxicants emitted. These data demonstrate the need to examine device and liquid characteristics to develop empirically informed, health-promoting regulatory policies. Policies may include setting product standards such that ECIG products cannot (1) have nicotine fluxes much greater than that of a cigarette to decrease the risk of dependence, (2) have nicotine fluxes that are very low and thus would have minimal appeal to cigarette smokers and may serve as starter products for youth or nontobacco users, and (3) emit large amounts of particulate matter and other toxicants.

Disruption of the Molecular Regulation of Mitochondrial Metabolism in Airway and Lung Epithelial Cells by Cigarette Smoke: Are Aldehydes the Culprit?

Chronic obstructive pulmonary disease (COPD) is a devastating lung disease for which cigarette smoking is the main risk factor. Acetaldehyde, acrolein, and formaldehyde are short-chain aldehydes known to be formed during pyrolysis and combustion of tobacco and have been linked to respiratory toxicity. Mitochondrial dysfunction is suggested to be mechanistically and causally involved in the pathogenesis of smoking-associated lung diseases such as COPD. Cigarette smoke (CS) has been shown to impair the molecular regulation of mitochondrial metabolism and content in epithelial cells of the airways and lungs. Although it is unknown which specific chemicals present in CS are responsible for this, it has been suggested that aldehydes may be involved. Therefore, it has been proposed by the World Health Organization to regulate aldehydes in commercially-available cigarettes. In this review, we comprehensively describe and discuss the impact of acetaldehyde, acrolein, and formaldehyde on mitochondrial function and content and the molecular pathways controlling this (biogenesis versus mitophagy) in epithelial cells of the airways and lungs. In addition, potential therapeutic applications targeting (aldehyde-induced) mitochondrial dysfunction, as well as regulatory implications, and the necessary required future studies to provide scientific support for this regulation, have been covered in this review.

Increased JUUL Emissions from Initial Puffs after Removing and Reinserting Pod

Standard laboratory electronic cigarette (ECIG) puffing protocols that do not consider user behaviors, such as removing and resinserting a pod, may underestimate emissions. This study compared JUUL emissions from four 10-puff bout procedures. We generated ECIG aerosol in a chamber using a JUUL device and measured concentrations of particulate matter ≤2.5 μm in diameter (PM_2.5). The JUUL pod was removed and reinserted 0 times, 1 time, 4 times, and 9 times in experiments 1-4, respectively. Mean real-time PM_2.5 concentration was 65.06 μg/m³ (SD = 99.53) for experiment 1, 375.50 μg/m³ (SD = 346.45) for experiment 2, 501.94 μg/m³ (SD = 450.00) for experiment 3, and 834.69 μg/m³ (SD = 578.34) for experiment 4. In this study, removing and reinserting a JUUL pod resulted in greater PM_2.5 concentrations compared to puffing protocols in which the JUUL pod was not removed and reinserted. ECIGs should be examined and evaluated based on ECIG users' real-world behaviors.

Risk assessment of components in tobacco smoke and e-cigarette aerosols: a pragmatic choice of dose metrics

BACKGROUND

Risk assessment of individual tobacco smoke components is important for the purpose of prioritization or selecting chemicals for monitoring products. Smoking is characterized by a highly varying, intermittent exposure and the challenge is to choose the most appropriate dose metric.

METHODS

Generally, average daily exposure estimates are used as dose metric, without considering temporal determinants. The applicability hereof is discussed in the context of choosing dose metrics for local respiratory tract effects and for systemic effects in a smoking scenario or for the use of e-cigarettes.

RESULTS

Using average daily exposure estimates for the smoking scenario can lead to erroneous risk evaluations for several reasons. Inhaled peak air concentrations during a puff can be two to three orders of magnitude higher than the calculated average daily inhaled concentration, which may impact the assessment of both systemic and local health effects. A pragmatic risk assessment is proposed, based on the Margin of Exposure (MoE) approach. The choice of an appropriate dose metric, such as inhaled concentration, inhaled dose or absorbed dose, depends on the type of effect. Temporal characteristics should be considered in the final step of the MoE approach, as is illustrated by two cases, glycerol and benzene.

CONCLUSION

The choice of an appropriate dose metric and inclusion of temporal determinants are important aspects in the risk assessment of individual smoke components. The proposed MoE approach provides the opportunity to weigh smoking-related exposure characteristics during the final step of the risk evaluation.

Smoking regular and low-nicotine cigarettes results in comparable levels of volatile organic compounds in blood and exhaled breath

Smokers are exposed to more than 6000 (toxic) smoke components including volatile organic compounds (VOCs). In this study VOCs levels in headspace of blood and exhaled breath, in the mainstream smoke of three types of cigarettes of one brand varying in declared tar, nicotine and carbon monoxide (TNCO) yields are investigated. The objective was to identify whether VOC levels correlate with TNCO yields of cigarettes smoked according to ISO 3308. Our data show that smoking regular and low-TNCO cigarettes result in comparable levels of VOCs in blood and exhaled breath. Hence, declared TNCO-yields as determined with the ISO 3308 machine smoking protocol are irrelevant for predicting VOC exposure upon human smoking. Venous blood and exhaled breath were sampled from 12 male volunteers directly before and 10 min after smoking cigarettes on 3 d (day 1 Marlboro Red (regular), day 2 Marlboro Prime (highly ventilated, low-TNCO), day 3 Marlboro Prime with blocked filter ventilation (taped)). Upon smoking, the levels of toluene, ethylbenzene, m/p-xylene, o-xylene, and 2,5-dimethylfuran in both headspace of venous blood and exhaled breath increase within the same range for all three cigarette types smoked. However, no strong correlation was found between VOC levels in exhaled breath and VOC levels in headspace of blood because of variations between the individual smoking volunteers. More research is required in order to use exhaled breath sampling as a non-invasive quantitative marker for volatile toxicants from cigarette smoke exposure of different brands.

Pesticides residues in tobacco smoke: risk assessment study

Pesticides are not only used on food but also on non-food crops, such as tobacco, to control a range of unwanted animal, plant, and microbial, fungal pests. The residue levels in tobacco leaves are expected to decline up to harvest, during drying, and when the leaves are further processed. Additional pesticides may also be applied to the finished product and residue levels may remain present even when the tobacco is burned. Human exposure to pesticide residues on tobacco occurs when residues remaining in cigarette smoke are inhaled. Based on this assumption, the objectives of this research were (i) to determine the level of pesticides residues in harvested tobacco leaves and (ii) to assess the risk of human exposure to these residues in tobacco smoke. Pesticide residues were detected in all analysed tobacco samples. These detected residues represent ten different active ingredients (AI), three of these AIs (thiodicarb, alachlor, and endosulfan) are no longer allowed in Europe. A 54.7% of these residues were quantifiable. Furthermore, it was found that with the use of solid-phase extraction sorbent (SPE) as adsorbent and n-hexane as solvent, higher recoveries of the pesticide residues in the tobacco smoke from the amount spiked can be obtained. It was also found that cigarette filters help to reduce the intake of residues of pesticides that may be present in cigarettes. Finally, the study concluded that both active smoking and passive smoking populations are exposed to pesticide residues in the tobacco smoke.