Effects of liquid nicotine concentration and flavour on the acceptability of electronic nicotine delivery systems (ENDS) among people who smoke participating in a randomised controlled trial to reduce cigarette consumption.

BACKGROUND: Research is needed to understand the acceptability of electronic nicotine delivery systems (ENDS) as a smoking reduction aid. This study examines the acceptability of ENDS by liquid nicotine concentration and flavour among people who smoke using ENDS to reduce their smoking. METHODS: People who smoke cigarettes but were naïve to ENDS participated in a double-blind randomised controlled trial to reduce conventional cigarette smoking. Participants were randomised to either a control cigarette substitute (CS) or one of three ENDS groups; 0 mg/mL, 8 mg/mL or 36 mg/mL nicotine concentration. ENDS flavour was chosen by the participant (tobacco or menthol). Participants reported their CS, ENDS and cigarettes per day (CPD) from the past 7 days at 1-month, 3-month and 6-month follow-up visits. Participants also reported side effects and measures of satisfaction, psychological reward, aversion and craving relief. Outcome variables were modelled using linear mixed effects by the following groups: liquid nicotine concentration, flavour and a flavour-nicotine concentration interaction. RESULTS: Participants (n=520) were 41.2% male, 67.3% white, had a mean age of 46.2 years and smoked a mean of 18.6 CPD (SD=7.74) at baseline. All flavour and concentration groups decreased CPD from baseline to all follow-up visits with the 36 mg/mL experiencing the greatest reduction, compared with the 0 mg/mL and 8 mg/mL groups. All groups except the 36 mg/mL group decreased their product use over time. The use of menthol flavour was associated with fewer side effects at 3 months (p=0.02) and lesser aversion at 1 month (p=0.03) compared with tobacco-flavoured ENDS. The 36 mg/mL group experienced the greatest craving relief and greatest aversion compared with other groups. CONCLUSIONS: Both nicotine concentration and flavour appear to have independent, as well as interactive, effects that influence ENDS acceptability among people who use cigarettes.

Nicotine and Cardiovascular Health: When Poison is Addictive - a WHF Policy Brief.

Nicotine is universally recognized as the primary addictive substance fuelling the continued use of tobacco products, which are responsible for over 8 million deaths annually. In recent years, the popularity of newer recreational nicotine products has surged drastically in many countries, raising health and safety concerns. For decades, the tobacco industry has promoted the myth that nicotine is as harmless as caffeine. Nonetheless, evidence shows that nicotine is far from innocuous, even on its own. In fact, numerous studies have demonstrated that nicotine can harm multiple organs, including the respiratory and cardiovascular systems. Tobacco and recreational nicotine products are commercialized in various types and forms, delivering varying levels of nicotine along with other toxic compounds. These products deliver nicotine in profiles that can initiate and perpetuate addiction, especially in young populations. Notably, some electronic nicotine delivery systems (ENDS) and heated tobacco products (HTP) can deliver concentrations of nicotine that are comparable to those of traditional cigarettes. Despite being regularly advertised as such, ENDS and HTP have demonstrated limited effectiveness as tobacco cessation aids in real-world settings. Furthermore, ENDS have also been associated with an increased risk of cardiovascular disease. In contrast, nicotine replacement therapies (NRT) are proven to be safe and effective medications for tobacco cessation. NRTs are designed to release nicotine in a slow and controlled manner, thereby minimizing the potential for abuse. Moreover, the long-term safety of NRTs has been extensively studied and documented. The vast majority of tobacco and nicotine products available in the market currently contain nicotine derived from tobacco leaves. However, advancements in the chemical synthesis of nicotine have introduced an economically viable alternative source. The tobacco industry has been exploiting synthetic nicotine to circumvent existing tobacco control laws and regulations. The emergence of newer tobacco and recreational nicotine products, along with synthetic nicotine, pose a tangible threat to established tobacco control policies. Nicotine regulations need to be responsive to address these evolving challenges. As such, governments should regulate all tobacco and non-medical nicotine products through a global, comprehensive, and consistent approach in order to safeguard tobacco control progress in past decades.

Building consensus on a set of ENDS-specific pictorial health warnings: a Delphi study among a tobacco control expert panel.

BACKGROUND: This study reports on the development of pictorial health warning labels for electronic nicotine delivery system (ENDS) using the Delphi approach with a panel of tobacco control experts. Twenty-four evidence-based ENDS-specific warnings corresponding to three themes (toxicity, health risks and specific harm) were developed and used in the Delphi study. METHODS: We conducted a three-round online Delphi study among 60 experts (55% female) between June 2022 and April 2023. We balanced the panel in areas of expertise and positions relevant to ENDS (risks, benefits). In round 1, participants rated the warnings on attention, relevance to evidence and perceived effectiveness (harm perception, motivation to quit) and provided suggestions for improvement. In rounds 2 and 3, participants ranked the revised warnings based on importance in each theme. We assessed levels of agreement between participants using interquartile deviations and medians. RESULTS: Warnings in theme 1, toxicity, received the highest ratings for perceived effectiveness on harm perception and encouraging quitting ENDS (p<0.05). Experts recommended using clear and affirmative text paired with emotion-provoking pictures and avoiding the rare side effects of ENDS. Most of the top-ranked warnings were from theme 3, ENDS-specific harm, pertained to lung damage, dual use of ENDS and cigarettes, nicotine addiction among youth, anti-ENDS industry sentiment and toxicity. DISCUSSION: This study developed 24 evidence-based ENDS health warning labels using a systematic process that included several rounds of expert panel feedback. These warnings can be used to advance ENDS prevention and tobacco control policies and further target different populations.

PMI-funded foundation for a smoke-free world: application of criteria to assess funding models that include financial support from the tobacco industry.

Recent changes to the leadership and the terms of tobacco industry financing of the Foundation for a Smoke-Free World (FSFW) have called for a revisiting of a paper published in 2009 where we proposed criteria and other considerations to assess possible funding models for research that include financial support from the tobacco industry. This paper reviews and attempts to apply the elements laid out in 2009 to the current state of FSFW. After discussing each criterion and consideration we conclude that, at this point in time, conducting a thorough assessment using our 2009 paper is not possible because critical details related to FSFW governance, decision-making and process have not been announced. Nonetheless, we hope this paper will remind the tobacco control community that the 2009 criteria exist and highlight the information needed and questions that might be asked of FSFW to help form judgements about this new iteration of the foundation. We further hope this will put the FSFW on notice that they need to address each of these criteria and speak publicly about their plans regarding the specific issues raised in the 2009 paper.

E-Cigarette Dependence and Depressive Symptoms Among Youth.

INTRODUCTION: Although the relationship between smoking and depression has been well-established, little is known about the association between use of e-cigarette and depression, particularly among youth and young adults. This study proposes that e-cigarette dependence, rather than simply use, serves as a potential stressor and may interact with pre-existing vulnerabilities to contribute to depression in youth, consistent with the diathesis-stress theory. This study examines the longitudinal association of vaping dependence and vaping frequency on depression symptoms among youth and young adults who have never smoked cigarettes. METHODS: People who used e-cigarettes in the past month who reported never smoking a cigarette (N=1,226) aged between 16 and 25 years were followed longitudinally every 3 months for up to 1 year beginning in 2020. The Penn State E-Cigarette Dependence Index at time t was used to predict depression symptoms assessed using the Center for Epidemiologic Studies Depression Scale at time t+1. RESULTS: A total of 32.1% reported vaping in the past month with the Penn State E-Cigarette Dependence Index score (M=8.5) and a Center for Epidemiologic Studies Depression Scale score (M=15.8). Higher vaping dependence scores were significantly associated with increased depression symptoms scores at follow-up among youth and adults (ß=0.08; 95% CI=0.01, 0.15), controlling for baseline depression symptom scores and covariates. Although vaping dependence was highly associated with vaping frequency level, no significant association between the frequency of vaping and depression was found (ß= -0.33; 95% CI= 1.21, 0.54). CONCLUSIONS: These results are consistent with the diathesis-stress model of the relationship between substance use and depression. Vaping dependence but not vaping frequency was associated with increased depressive symptoms among people who never smoked cigarettes.

Influence of nicotine form and nicotine flux on puffing behavior and mouth-level exposure to nicotine from electronic nicotine delivery systems.

BACKGROUND: Nicotine form (freebase/protonated) and nicotine flux (rate at which nicotine is emitted) are two factors that can affect the dose of nicotine inhaled by individuals using electronic nicotine delivery systems (ENDS) because they can influence puffing behavior. The nicotine dose for each puff also is directly proportional to nicotine flux (i.e., dose/puff=nicotine flux*puff duration). This study examines the effect of nicotine form and flux on puffing parameters and mouth-level nicotine exposure. METHODS: Thirty-two dual ENDS and combustible cigarette participants completed five visits that differed by nicotine form (freebase or protonated) and nicotine flux (14 or 35µg/sec); a zero-nicotine condition was a negative control. Participants used a Subox Mini C ENDS, powered at 20W, during a 10-puff directed bout (B1) followed by a one-hour ad libitum bout (B2). Puffing parameters and mouth-level nicotine exposure were assessed using the American University of Beirut REALTIME instrument. RESULTS: Relative to protonated nicotine, freebase nicotine was associated with lower total puff duration (puff duration*number of puffs), lower flow rate in B1, lower liquid consumption, and lower mouth-level nicotine exposure. Increasing nicotine flux from 14 to 35µg/sec was associated with lower total puff duration in both bouts, as well as lower liquid consumption. Increasing nicotine flux was associated with higher mouth-level nicotine exposure in B1 only. CONCLUSION: ENDS with protonated nicotine may enhance nicotine exposure by promoting longer puffing and thus greater dose delivered. This work highlights the importance of accounting for interactions between nicotine form and flux when considering nicotine regulation for ENDS.

Nicotine flux as a powerful tool for regulating nicotine delivery from e-cigarettes: Protocol of two complimentary randomized crossover clinical trials.

INTRODUCTION: Electronic cigarette (EC) use has increased rapidly in the last decade, especially among youth. Regulating nicotine delivery from ECs could help curb youth uptake and leverage EC use in harm reduction yet is complicated by varying device and liquid variables that affect nicotine delivery. Nicotine flux, the nicotine emission rate, is a parameter that incorporates these variables and focuses on the performance rather than the design of an EC. Nicotine flux therefore could be a powerful regulatory tool if it is shown empirically to predict nicotine delivery and subjective effects related to dependence. METHODS AND ANALYSIS: This project consists of two complementary clinical trials. In Trial I, we will examine the relationship between nicotine flux and the rate and dose of nicotine delivery from ECs, hence, impacting abuse liability. It will also examine the extent to which this relationship is mediated by nicotine form (i.e., freebase versus protonated). At Yale School of Medicine (YSM), study participants will puff EC devices under conditions that differ by flux and form, while arterial blood is sampled in high time resolution. In Trial II, we will assess the relationship between nicotine flux, form, and subjective effects. At the American University of Beirut (AUB), participants will use EC devices with varying nicotine fluxes and forms, while dependency measures, such as the urge to use ECs, nicotine craving, and withdrawal symptoms, will be assessed. We will also monitor puffing intensity and real-time exposure to toxicants. ETHICS AND DISSEMINATION: The protocol of Trial I and Trial II was approved by YSM and AUB IRBs, respectively. We will disseminate study results through peer-reviewed publications and conference presentations. TRIAL REGISTRATION: NCT05706701 for Trial I and NCT05430334 for Trial II.

Interventions for waterpipe smoking cessation.

BACKGROUND: While cigarette smoking has declined globally, waterpipe smoking is rising, especially among youth. The impact of this rise is amplified by mounting evidence of its addictive and harmful nature. Waterpipe smoking is influenced by multiple factors, including appealing flavors, marketing, use in social settings, and misperceptions that waterpipe is less harmful or addictive than cigarettes. People who use waterpipes are interested in quitting, but are often unsuccessful at doing so on their own. Therefore, developing and testing waterpipe cessation interventions to help people quit was identified as a priority for global tobacco control efforts.  OBJECTIVES: To evaluate the effectiveness of tobacco cessation interventions for people who smoke waterpipes. SEARCH METHODS: We searched the Cochrane Tobacco Addiction Review Group Specialized Register from database inception to 29 July 2022, using variant terms and spellings ('waterpipe' or 'narghile' or 'arghile' or 'shisha' or 'goza' or 'narkeela' or 'hookah' or 'hubble bubble'). We searched for trials, published or unpublished, in any language. SELECTION CRITERIA: We sought randomized controlled trials (RCTs), quasi-RCTs, or cluster-RCTs of any smoking cessation interventions for people who use waterpipes, of any age or gender. In order to be included, studies had to measure waterpipe abstinence at a three-month follow-up or longer. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcome was abstinence from waterpipe use at least three months after baseline. We also collected data on adverse events. Individual study effects and pooled effects were summarized as risk ratios (RR) and 95% confidence intervals (95% CI), using Mantel-Haenszel random-effects models to combine studies, where appropriate. We assessed statistical heterogeneity with the I2 statistic. We summarized secondary outcomes narratively. We used the five GRADE considerations (risk of bias, inconsistency of effect, imprecision, indirectness, and publication bias) to assess the certainty of the body of evidence for our primary outcome in four categories high, moderate, low, or very low. MAIN RESULTS: This review included nine studies, involving 2841 participants. All studies were conducted in adults, and were carried out in Iran, Vietnam, Syria, Lebanon, Egypt, Pakistan, and the USA. Studies were conducted in several settings, including colleges/universities, community healthcare centers, tuberculosis hospitals, and cancer treatment centers, while two studies tested e-health interventions (online web-based educational intervention, text message intervention). Overall, we judged three studies to be at low risk of bias, and six studies at high risk of bias. We pooled data from five studies (1030 participants) that tested intensive face-to-face behavioral interventions compared with brief behavioral intervention (e.g. one behavioral counseling session), usual care (e.g. self-help materials), or no intervention. In our meta-analysis, we included people who used waterpipe exclusively, or with another form of tobacco. Overall, we found low-certainty evidence of a benefit of behavioral support for waterpipe abstinence (RR 3.19 95% CI 2.17 to 4.69; I2 = 41%; 5 studies, N = 1030). We downgraded the evidence because of imprecision and risk of bias. We pooled data from two studies (N = 662 participants) that tested varenicline combined with behavioral intervention compared with placebo combined with behavioral intervention. Although the point estimate favored varenicline, 95% CIs were imprecise, and incorporated the potential for no difference and lower quit rates in the varenicline groups, as well as a benefit as large as that found in cigarette smoking cessation (RR 1.24, 95% CI 0.69 to 2.24; I2 = 0%; 2 studies, N = 662; low-certainty evidence). We downgraded the evidence because of imprecision. We found no clear evidence of a difference in the number of participants experiencing adverse events (RR 0.98, 95% CI 0.67 to 1.44; I2 = 31%; 2 studies, N = 662). The studies did not report serious adverse events.   One study tested the efficacy of seven weeks of bupropion therapy combined with behavioral intervention. There was no clear evidence of benefit for waterpipe cessation when compared with behavioral support alone (RR 0.77, 95% CI 0.42 to 1.41; 1 study, N = 121; very low-certainty evidence), or with self-help (RR 1.94, 95% CI 0.94 to 4.00; 1 study, N = 86; very low-certainty evidence).  Two studies tested e-health interventions. One study reported higher waterpipe quit rates among participants randomized to either a tailored mobile phone or untailored mobile phone intervention compared with those randomized to no intervention (RR 1.48, 95% CI 1.07 to 2.05; 2 studies, N = 319; very low-certainty evidence). Another study reported higher waterpipe abstinence rates following an intensive online educational intervention compared with a brief online educational intervention (RR 1.86, 95% CI 1.08 to 3.21; 1 study, N = 70; very low-certainty evidence).  AUTHORS' CONCLUSIONS: We found low-certainty evidence that behavioral waterpipe cessation interventions can increase waterpipe quit rates among waterpipe smokers. We found insufficient evidence to assess whether varenicline or bupropion increased waterpipe abstinence; available evidence is compatible with effect sizes similar to those seen for cigarette smoking cessation.  Given e-health interventions' potential reach and effectiveness for waterpipe cessation, trials with large samples and long follow-up periods are needed. Future studies should use biochemical validation of abstinence to prevent the risk of detection bias. Finally, there has been limited attention given to high-risk groups for waterpipe smoking, such as youth, young adults, pregnant women, and dual or poly tobacco users. These groups would benefit from targeted studies.

Electronic Nicotine Delivery System flavor use over time by age group in the US: A longitudinal analysis.

INTRODUCTION: The prevalence of flavor use in Electronic Nicotine Delivery Systems (ENDS) has been assessed in numerous studies, but limited research has focused on flavor use trends and maintenance of flavor preference over time. This study investigated the general trends and maintenance of ENDS flavor use for youth (aged 12-17 years), young adults (aged 18-24 years), and older adults (aged ≥25 years) between 2014 and 2019. METHODS: Population Assessment of Tobacco and Health (PATH) Study Wave 2 (2014-2015), Wave 3 (2015-2016), Wave 4 (2016-2017), and Wave 5 (2018-2019) youth and adult data were used. Cross-sectional flavor use prevalence (trends) and flavor maintenance (using the same flavor category in at least three consecutive waves) were assessed. RESULTS: The most reported primary flavor category was fruit among all age groups in all waves. Candy/desserts in waves two, three, four, and menthol/mint in wave five were the second most reported flavor in all age groups. The highest increase was observed for menthol/mint use among youth between wave two (21.9%) and five (58.1%) (OR=5.33; 95% CI: 3.58-7.96). Overall, 37.6% of fruit flavor users, 25.3% of candy/desserts users, 32.0% of menthol/mint users, and 33.4% of tobacco flavor users, maintained use of the same flavor in at least three consecutive waves. CONCLUSIONS: Fruit flavor had the highest percentages of use and maintenance between 2014 and 2019. While the maintenance of fruit and candy/desserts flavors were higher among youth, adults had substantially higher maintenance percentages for menthol/mint and tobacco flavor. There was a substantial increase in menthol/mint use in wave five among youth, which may affect ENDS flavor maintenance patterns in the future. Understanding maintenance of flavors over time can inform regulation of ENDS flavors.

Comparison of design characteristics and toxicant emissions from Vuse Solo and Alto electronic nicotine delivery systems.

INTRODUCTION: Vuse Solo is the first electronic nicotine delivery system (ENDS) authorised by the US Food and Drug Administration for marketing in the USA. Salient features of the Vuse Solo product such as nicotine form, draw resistance, power regulation and electrical characteristics have not been reported previously, and few studies have examined the nicotine and other toxicant emissions of this product. We investigated the design characteristics and toxicant emissions of the Solo as well as Alto, another Vuse product with a greater market share than Solo. METHODS: Total/freebase nicotine, propylene glycol to vegetable glycerin ratio, carbonyl compounds (CC) and reactive oxygen species (ROS) were quantified by gas chromatography, high-performance liquid chromatography and fluorescence from aerosol emissions generated in 15 puffs of 4 s duration. The electric power control system was also analysed. RESULTS: The average power delivered was 2.1 W and 3.9 W for Solo and Alto; neither system was temperature-controlled. Vuse Solo and Alto, respectively, emitted nicotine at a rate of 38 µg/s and 115 µg/s, predominantly in the protonated form (>90%). Alto's ROS yield was similar to a combustible cigarette and one order of magnitude greater than that of Solo. Total carbonyls from both products were two orders of magnitude lower than combustible cigarettes. CONCLUSION: Vuse Solo is an above-Ohm ENDS that emits approximately one-third the nicotine flux of a Marlboro Red cigarette (129 µg/s) and considerably lower CC and ROS yields than a combustible cigarette. With its higher power, the nicotine flux and ROS yield from Alto are similar to Marlboro Red levels; Alto may thus present greater abuse liability than the lower sales-volume Solo.

The Vaping and Patterns of e-Cigarette Use Research Study: Protocol for a Web-Based Cohort Study.

BACKGROUND: In total, 3.2% of American adults report using e-cigarettes every day or some days. The Vaping and Patterns of E-cigarette Use Research (VAPER) Study is a web-based longitudinal survey designed to observe patterns in device and liquid use that suggest the benefits and unintended consequences of potential e-cigarette regulations. The heterogeneity of the e-cigarette devices and liquids on the market, the customizability of the devices and liquids, and the lack of standardized reporting requirements result in unique measurement challenges. Furthermore, bots and survey takers who submit falsified responses are threats to data integrity that require mitigation strategies. OBJECTIVE: This paper aims to describe the protocols for 3 waves of the VAPER Study and discuss recruitment and data processing experiences and lessons learned, including the benefits and limitations of bot- and fraudulent survey taker-related strategies. METHODS: American adults (aged ≥21 years) who use e-cigarettes ≥5 days per week are recruited from up to 404 Craigslist catchment areas covering all 50 states. The questionnaire measures and skip logic are designed to accommodate marketplace heterogeneity and user customization (eg, different skip logic pathways for different device types and customizations). To reduce reliance on self-report data, we also require participants to submit a photo of their device. All data are collected using REDCap (Research Electronic Data Capture; Vanderbilt University). Incentives are US $10 Amazon gift codes delivered by mail to new participants and electronically to returning participants. Those lost to follow-up are replaced. Several strategies are applied to maximize the odds that participants who receive incentives are not bots and are likely to possess an e-cigarette (eg, required identity check and photo of a device). RESULTS: In total, 3 waves of data were collected between 2020 and 2021 (wave 1: n=1209; wave 2: n=1218; wave 3: n=1254). Retention from waves 1 to 2 was 51.94% (628/1209), and 37.55% (454/1209) of the wave 1 sample completed all 3 waves. These data were mostly generalizable to daily e-cigarette users in the United States, and poststratification weights were generated for future analyses. Our data offer a detailed examination of users' device features and specifications, liquid characteristics, and key behaviors, which can provide more insights into the benefits and unintended consequences of potential regulations. CONCLUSIONS: Relative to existing e-cigarette cohort studies, this study methodology has some advantages, including efficient recruitment of a lower-prevalence population and collection of detailed data relevant to tobacco regulatory science (eg, device wattage). The web-based nature of the study requires several bot- and fraudulent survey taker-related risk-mitigation strategies, which can be time-intensive. When these risks are addressed, web-based cohort studies can be successful. We will continue to explore methods for maximizing recruitment efficiency, data quality, and participant retention in subsequent waves. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/38732.

Nicotine Dependence among Current Cigarette Smokers Who Use E-Cigarettes and Cannabis.

BACKGROUND: Co-use of tobacco and cannabis and dual use of cigarettes and e-cigarettes are very common among young adults. However, it is unclear whether co-use of cigarettes, e-cigarettes, and/or cannabis is associated with higher levels of nicotine dependence than cigarette-only use. We investigated the relationship between cigarette/nicotine dependence and co-use of tobacco and cannabis among 4 groups of cigarette smokers aged 18-35: cigarette-only smokers, cigarette-e-cigarette (CIG-ECIG) co-users, cigarette-cannabis (CIG-CAN) co-users, and cigarette-e-cigarette-cannabis (CIG-ECIG-CAN) co-users. METHODS: Data were from a 2018 cross-sectional survey based on a national convenience sample of smokers aged 18-35 (n = 315). Cigarette/nicotine dependence was measured by the Fagerstrom Test of Nicotine Dependence (FTND) and e-cigarette dependence was measured by the Penn State E-cigarette Dependence Index. Bivariate analyses examined sociodemographic and tobacco/other substance use characteristics by co-use status and multivariable linear regression assessed the relationship between co-use and nicotine dependence. RESULTS: In the sample, 27.6% were cigarette-only smokers, 24.8% were CIG-ECIG, 27.6% were CIG-CAN, and 20.0% were CIG-ECIG-CAN co-users. Significant differences were observed in sociodemographic and tobacco/other substance use characteristics by co-use status. E-cigarette co-users had low e-cigarette dependence, but moderate FTND scores. In adjusted analyses, only CIG-ECIG co-use was associated with higher FTND scores compared to cigarette-only smoking. However, CIG-ECIG and CIG-ECIG-CAN co-use were associated with higher FTND scores compared to CIG-CAN co-use. CONCLUSIONS: Co-use of cigarettes and e-cigarettes was associated with greater nicotine dependence among smokers aged 18-35. Additional research is needed to understand the underlying mechanisms of these relationships and inform prevention efforts.

Smoking, e-cigarettes and the effect on respiratory symptoms among a population sample of youth: Retrospective cohort study.

INTRODUCTION: E-cigarettes have been steadily increasing in popularity, both as cessation methods for smoking and for recreational and social reasons. This increase in vaping may pose cardiovascular and respiratory risks. We aimed to assess respiratory symptoms in youth users of e-cigarettes and cigarettes. METHODS: A retrospective survey design was utilized to assess Canadian youth aged 16-25 years. Participants were recruited from the Ontario Tobacco Research Unit Youth and Young Adult Research Registration Panel November 2020 to March 2021. A total of 3082 subjects completed the baseline survey. Of these, 2660 individuals who did not have asthma were included in the analysis. The exposure of interest was pack-equivalent years, a novel measure of vaping exposure equivalent conceptually to cigarette pack years incorporating number of puffs per day, number of days vaped per month, and number of years vaped. Respiratory symptoms were measured using the five-item Canadian Lung Health Test. Poisson regression analyses were performed while adjusting for demographic confounders, stratified by smoking status. A non-stratified model tested the interaction of status and vaping dose and the effect of vaping device used was assessed among ever vapers. Analyses controlled for demographic characteristics, use of cannabis and alcohol, and survey date. RESULTS: Each additional puff year increased the rate ratio (RR) of respiratory symptoms by a factor of 11.36 (95% CI: 4.61-28.00; p<0.001) for never smokers, but among current daily smokers higher pack-equivalent years were not associated with more respiratory symptoms (RR=0.83; 95% CI: 0.23-3.11). Among current vapers, those using pod-style devices were more likely to have more respiratory symptoms (RR=1.25; 95% CI: 1.08-1.45) after adjusting for dose. CONCLUSIONS: Vaping is associated with an increased risk of reporting respiratory symptoms among never smoking youth and non-daily ever cigarette smokers. Use of e-cigarettes among non-smokers should be discouraged.

Impact of smoking intensity and device cleaning on IQOS emissions: comparison with an array of cigarettes.

SIGNIFICANCE: IQOS is a heated tobacco product that has been widely advertised by Philip Morris International (PMI) as a reduced-exposure product compared with cigarettes. Reduced exposure results from reduced emission of toxicants which could be influenced by product constituents and user behaviour. This study aims to assess the influence of user behaviour, including device cleaning and puffing parameters, on toxicant emissions from IQOS. METHODS: IQOS aerosols were generated by a smoking machine using the combination of two cleaning protocols (after 1 stick vs 20 sticks) and five puffing regimes (including standard cigarette puffing regimes and IQOS-tailored regimes). The generated aerosols were analysed by targeted methods for phenol and carbonyl quantification, and by chemical screening for the identification of unknown compounds. RESULTS: Puffing parameters significantly affected phenol and carbonyl emissions while device cleaning had no effect. Harsher puffing conditions like more, longer, and larger puffs yielded higher levels for most toxicant emissions. Comparing the obtained data with data reported by PMI on 50 cigarette brands smoked under different puffing regimes showed various trends for phenol and carbonyl emissions, with IQOS emissions sometimes higher than cigarettes. Also, the chemical screening resulted in the tentative identification of ~100 compounds in the IQOS aerosols (most of limited toxicity data). CONCLUSION: This study showed that puffing parameters, but not device cleaning, have significant effects on carbonyl, phenol and other emissions. Data analysis highlighted the importance of comparing IQOS emissions with an array of commercial cigarettes tested under different puffing regimes before accepting reduced exposure claims.

Acute effects of flavored Black and mild cigars among young adult cigarette smokers.

The U.S. Food and Drug Administration proposed new product standards that would ban characterizing flavors (other than tobacco) in cigars. To inform this regulatory action, we compared physiological effects, use behavior, and subjective effects of four popular cigar flavors in cigar-naïve young adult cigarette smokers. Across five laboratory visits, participants (n = 25) used and evaluated own brand (OB) cigarettes or Black & Mild cigars (original, wine, apple, and cream flavors). Linear mixed models tested differences in saliva nicotine, exhaled carbon monoxide (CO), heart rate (HR), blood pressure (BP), puff topography, and subjective effects (p < .05). Compared to all cigars, OB resulted in higher nicotine boost (953 vs. < 300 ng/ml) and lower CO boost (4 vs. 8-9 ppm). Nicotine boost for original cigars (283 ng/ml) was significantly higher than wine (190 ng/ml). All products significantly increased HR/BP relative to baseline, but across time wine and apple cigars were associated with significantly lower HR than OB and BP effects varied. Relative to OB, participants took approximately 0.5 s longer puffs for all cigars and took significantly larger puffs (+ 21%-24%) of original, wine, and apple cigars. OB was rated more positively than all cigars, which had similar subjective effects. Wine cigars were disliked most and were less effective in reducing tobacco abstinence symptoms than OB; cream cigars were harsher and had stronger flavor intensity than original. The consistency in toxicant exposure, use behavior, and subjective effects across cigar flavors, including original, highlights the need for product standards to interpret characterizing flavors subject to prohibition broadly. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Impact of Canada's menthol cigarette ban on quitting among menthol smokers: pooled analysis of pre-post evaluation from the ITC Project and the Ontario Menthol Ban Study and projections of impact in the USA.

INTRODUCTION: Between 2015 and 2018, Canada banned menthol cigarettes. This study pooled data from two pre-post cohort studies (the Ontario Menthol Ban Study, and the International Tobacco Control Policy Evaluation (ITC) Canada Survey, conducted in seven provinces) to derive more precise estimates of the impact of Canada's menthol ban on quitting and to apply these estimates to project the impact of a menthol ban in the USA. METHODS: Weighted multivariable logistic analyses compared post-ban quit success of menthol smokers with non-menthol smokers (for daily smokers and for all (daily + non-daily) smokers), controlling for sex, age, ethnicity, education, baseline smoking status, baseline cigarettes per day and study regions. Projections to the USA were created by multiplying the effect size of the Canadian menthol ban on quitting (percentage of increased quitting among menthol smokers) by the number of menthol smokers overall and among African Americans, from the 2019 National Survey on Drug Use and Health. RESULTS: After the menthol cigarette ban, menthol smokers were more likely than non-menthol smokers to have quit smoking among daily smokers (difference=8.0%; 95% CI: 2.4% to 13.7%,p=0.005) and all (daily+non-daily) smokers (difference=7.3%; 95% CI: 2.1% to 12.5%,p=0.006). The projected number of smokers who would quit after a US menthol ban would be 789 724 daily smokers (including 199 732 African Americans) and 1 337 988 daily+non-daily smokers (including 381 272 African Americans). CONCLUSIONS: This pooled analysis of Canada's menthol cigarette ban provides the foundation for estimating the impact of menthol bans in the USA and other countries. Projections suggest that a US menthol cigarette ban would have a substantial impact on increasing quitting.

Effectiveness of ENDS, NRT and medication for smoking cessation among cigarette-only users: a longitudinal analysis of PATH Study wave 3 (2015-2016) and 4 (2016-2017), adult data.

BACKGROUND: Research is inconclusive on the effectiveness of electronic nicotine delivery systems (ENDS) as cigarette cessation aids compared with nicotine replacement therapy (NRT) or non-NRT medication. This study compared the cigarette cessation rates for ENDS, NRT and non-NRT medication. METHOD: Population Assessment of Tobacco and Health Study wave 3 cigarette-only users who used ENDS, NRT or non-NRT medication (varenicline and bupropion) to quit smoking between wave 3 and 4 were included. 'Cessation' was defined as being a former cigarette smoker in wave 4. χ2, logistic regression, and a sensitivity analysis with Bayes factor assessed the association between quitting smoking and method used. RESULTS: Among 6794 cigarette-only users, 532 used ENDS (n=75), NRT (n=289), non-NRT medication (n=68), or a combination of NRT and non-NRT medication (n=100) to quit smoking between wave 3 and 4. The percentages of quitting smoking among those who used ENDS, NRT, non-NRT medication, and a combination of NRT and non-NRT medication were 16.2% (n=14), 16.1% (n=47), 17.7% (n=13), and 14.8% (n=12), respectively (p=0.97). None of the cigarette-only users who used ENDS to quit smoking became ENDS-only users in wave 4; 37.6% became dual users of ENDS and cigarettes. CONCLUSION: No differences were found when cessation rates of ENDS, NRT or non-NRT medication were compared. Given uncertainty about the long-term health effect of ENDS and the likelihood of becoming dual users, people who smoke and need assistance quitting should be encouraged to use current Food and Drug Administration-approved cessation methods until more effective methods are developed.

Interactive effects of protonated nicotine concentration and device power on ENDS nicotine delivery, puff topography, and subjective effects.

Electronic nicotine delivery systems (ENDSs) produce an aerosol by heating a liquid that often contains nicotine. The nicotine can be protonated that may make the aerosol easier to inhale than freebase nicotine. This study's purpose is to determine, in cigarette smokers and ENDS users, the effects of three concentrations of protonated nicotine aerosolized at two different power settings. Forty-five participants (22 cigarette smokers and 23 ENDS users) completed some or all of six sessions that varied by liquid nicotine concentration (10, 15, or 30 mg/ml protonated nicotine) and device power (15 or 30 W). Participants took 10 puffs from each product and then used each product for 90 min ad libitum. Plasma nicotine concentration, subjective effects, and puff topography were measured. Results showed increases in plasma nicotine concentration in all conditions, with greater plasma nicotine increases in higher watt, higher nicotine concentration conditions, as well as greater nicotine delivery for ENDS users compared to cigarette smokers. For puff topography, puff duration and volume decreased as nicotine concentration and power increased, and ENDS users took longer and larger puffs than cigarette smokers. Participants rated the higher watt, higher nicotine concentration conditions as harsher and with more throat hit. Overall, these results suggest that device characteristics and liquid constituents interact to influence users' plasma nicotine delivery and should be considered together when regulating ENDS. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Bronchoalveolar Lavage (BAL) and Pathologic Assessment of Electronic Cigarette or Vaping Product Use-associated Lung Injury (EVALI): The EVALI-BAL Study, A Multicenter Cohort.

BACKGROUND: E-cigarette or vaping-use related acute lung injury (EVALI) is a spectrum of radiographic and histologic patterns consistent with acute to subacute lung injury. However, limited data exist characterizing bronchoalveolar lavage (BAL) findings. The goal of this study is to further define the pathologic findings from BAL and biopsy samples of subjects with EVALI across 7 institutions. METHODS: A multicentered registry of patients admitted with EVALI who underwent flexible bronchoscopy with BAL+/-transbronchial biopsy from July 2019 to April 2021 was compiled for retrospective evaluation from 7 academic institutions throughout the United States. Radiographic and cytopathologic findings and frequencies were correlated with the substance vaped. RESULTS: Data from 21 subjects (42.9% women) who were predominantly White (76.2%) with a median age of 25 years (range, 16 to 68) with EVALI were included in this study. Sixteen patients (76.2%) reported use of tetrahydrocannabinol; the remainder used nicotine. BAL was performed in 19 of the 21 subjects, and transbronchial lung biopsy was performed in 7 subjects. BAL findings revealed neutrophilic predominance (median, 59.5%, range, 3.1 to 98) in most cases. Ten BAL samples demonstrated pulmonary eosinophilia ranging from 0.2% to 49.1% with one subject suggesting a diagnosis of acute eosinophilic pneumonia associated with the use of e-cigarettes. Lipid-laden macrophages were noted in 10 of 15 reports (66.7%). Transbronchial biopsy most frequently demonstrated patterns of organizing pneumonia (57.1%). CONCLUSION: EVALI-associated BAL findings typically demonstrate a spectrum of nonspecific inflammatory changes, including neutrophilia, lipid-laden macrophages, and in some cases eosinophilia.

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.