Potential deaths averted in USA by replacing cigarettes with e-cigarettes

Composition of e-cigarette aerosols: A review and risk assessment of selected compounds

The potential harms and benefits of e-cigarettes, or electronic nicotine delivery systems (ENDS), have received significant attention from public health and regulatory communities. Such products may provide a reduced risk means of nicotine delivery for combustible cigarette smokers while being inappropriately appealing to nicotine naive youth. Numerous authors have examined the chemical complexity of aerosols from various open- and closed-system ENDS. This body of literature is reviewed here, with the risks of ENDS aerosol exposure among users evaluated with a margin of exposure (MoE) approach for two non-carcinogens (methylglyoxal, butyraldehyde) and a cancer risk analysis for the carcinogen N-nitrosonornicotine (NNN). We identified 96 relevant papers, including 17, 13, and 5 reporting data for methylglyoxal, butyraldehyde, and NNN, respectively. Using low-end (minimum aerosol concentration, low ENDS use) and high-end (maximum aerosol concentration, high ENDS use) assumptions, estimated doses for methylglyoxal (1.78 × 10-3-135 μg/kg-bw/day) and butyraldehyde (1.9 × 10-4-66.54 μg/kg-bw/day) corresponded to MoEs of 227-17,200,000 and 271-280,000,000, respectively, using identified points of departure (PoDs). Doses of 9.90 × 10-6-1.99 × 10-4 μg/kg-bw/day NNN corresponded to 1.4-28 surplus cancers per 100,000 ENDS users, relative to a NNN-attributable surplus of 7440 per 100,000 cigarette smokers. It was concluded that methylglyoxal and butyraldehyde in ENDS aerosols, while not innocuous, did not present a significant risk of irritant effects among ENDS users. The carcinogenic risks of NNN in ENDS aerosols were reduced, but not eliminated, relative to concentrations reported in combustible cigarette smoke.

Modeling the population health impact of accurate and inaccurate perceptions of harm from nicotine

BACKGROUND

Scientific evidence clearly demonstrates that inhaling the smoke from the combustion of cigarettes is responsible for most of the harm caused by smoking, and not the nicotine. However, a majority of U.S. adults who smoke inaccurately believe that nicotine causes cancer which may be a significant barrier, preventing switching to potentially reduced risk, non-combustible products like electronic nicotine delivery systems (ENDS) and smokeless tobacco (ST). We assessed the population health impact associated with nicotine perceptions.

METHODS

Using a previously validated agent-based model to the U.S. population, we analyzed nationally representative data from the Population Assessment of Tobacco and Health (PATH) study to estimate base case rates of sustained (maintained over four waves) cessation and switching to non-combustible product use, by sex. Nicotine perception scenarios were determined from PATH data. The overall switch rate from smoking in Wave 4 to non-combustible product use in Wave 5 (3.94%) was stratified based on responses to the nicotine perception question "Do you believe nicotine is the chemical that causes most of the cancer caused by smoking cigarettes?", (four-item scale from "Definitely not" to "Definitely yes"). The relative percent change between the overall and stratified rates, corresponding to each item, was used to adjust the base case rates of switching, to determine the impact, if all adults who smoke exhibited switching behaviors based on responses to the nicotine perceptions question. The public health impact of nicotine perceptions was estimated as the difference in all-cause mortality between the base case and the four nicotine perception scenarios.

RESULTS

Switch rates associated with those who responded, "Definitely not" (8.39%) resulted in a net benefit of preventing nearly 800,000 premature deaths over an 85-year period. Conversely switch rates reflective of those who responded, "Definitely yes" (2.59%) resulted in a net harm of nearly 300,000 additional premature deaths over the same period.

CONCLUSIONS

Accurate knowledge regarding the role of nicotine is associated with higher switch rates and prevention of premature deaths. Our findings suggest that promoting public education to correct perceptions of harm from nicotine has the potential to benefit public health.

A systematic review of the modelling and economic evaluation studies assessing regulatory options for e-cigarette use

BACKGROUND

Governments around the world are considering regulating access to nicotine e-cigarettes to prevent uptake among youth however people that smoke tobacco may use them to assist with smoking cessation. The health and cost implications of regulating e-cigarette use among populations are unknown but have been explored in modelling studies. We reviewed health economic evaluation and simulation modelling studies that assessed long-term consequences and interpret their potential usefulness for decision-makers.

METHODS

A systematic review with a narrative synthesis was undertaken. Six databases were searched for modelling studies evaluating population-level e-cigarette control policies or interventions restricting e-cigarette use versus more liberalized use. Studies were required to report the outcomes of life years, quality-adjusted life years (QALYs) and/or healthcare costs. The quality of the studies was assessed using two quality assessment tools.

RESULTS

In total, 15 studies were included with nine for the United States and one each for the United Kingdom, Italy, Australia, Singapore, Canada, and New Zealand. Three studies included cost-utility analyses. Most studies involved health state transition (or Markov) closed cohort models. Many studies had limitations with their model structures, data input quality and transparency, and insufficient analyses handling model uncertainty. Findings were mixed with 11 studies concluding that policies permitting e-cigarette use lead to net benefits and 4 studies concluding net losses in life-years or QALYs and/or healthcare costs.Five studies had industry conflicts of interest.

CONCLUSIONS

While authors did conclude net benefit than net harm in more of the studies so far conducted, the significant limitations that we identified with many of the studies in this review, make it uncertain whether or not countries can expect net population harms or benefits of restrictive versus unrestrictive e-cigarette policies. The generalizability of the findings is limited for decision-makers. In light of the deep uncertainty around the health and economic outcomes of e-cigarettes, simulation modelling methods and uncertainty analyses should be strengthened.

The effect of e-cigarettes on cognitive function: a scoping review

AIM

Much research has been conducted on the acute effects of nicotine on human cognitive performance, demonstrating both enhancing and impairing cognitive effects. With the relatively recent introduction of electronic cigarettes ('e-cigarettes') as a smoking cessation device, little is known about the cognitive effects of e-cigarettes specifically, either as a nicotine replacement device or in the absence of nicotine. The purpose of this review was to present an overview of evidence from empirical studies on the effect of e-cigarettes on cognitive function.

APPROACH

Guided by Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews guidelines (PRISMA-ScR), SCOPUS, PubMed, and EBSCOhost were searched from 2006, the year e-cigarettes were introduced, to June 2023 for relevant papers, along with reference lists checked for additional papers.

KEY FINDINGS

Seven experimental and four cross-sectional survey studies were identified and included. The majority of the studies only include regular and current cigarette smokers and primarily assessed the acute cognitive effect of e-cigarettes relative to nicotine. While the findings primarily suggest either no or positive effect of e-cigarettes on cognition in cigarette smokers, associations between e-cigarettes and cognitive impairments in memory, concentration and decision making were reported in both cigarette smokers and never-smokers.

IMPLICATIONS AND CONCLUSIONS

The acute cognitive effect of e-cigarettes on regular cigarette smokers appears minimal. However, long-term cognitive effect and their effects on never-smokers are unclear. Given that the increased numbers of e-cigarette users are non-smokers and/or adolescents, research with those naïve to nicotine and a developmentally vulnerable adolescent population on its long-term effect is needed.

Associations between vaping and daily cigarette consumption among individuals with psychological distress

INTRODUCTION

Individuals with behavioral health conditions smoke at significantly higher rates and have been resistant to existing smoking cessation efforts. A clearer understanding of associations between vaping and daily cigarette consumption in this vulnerable population is warranted.

METHODS

We analyzed data from the 2014-2018 National Health Interview Survey (NHIS) to examine whether vaping was associated with differences in number of cigarettes smoked per day (CPD) among adults who smoke daily and have varying levels of psychological distress.

RESULTS

After adjustment for sociodemographic covariates, individuals who vaped every day smoked on average 1.48 fewer cigarettes per day than individuals who never vaped (p<0.01), while individuals who vaped some days and individuals who ever but no longer vaped smoked 0.77 and 1.48 more CPD, respectively, than individuals who never vaped. Differences between those who vaped every day and those who never vaped were even greater among those with moderate psychological distress (-2.21 CPD, p<0.01).

CONCLUSIONS

Our findings suggest that use of vaping devices may be associated with lower daily cigarette use among individuals with psychological distress, potentially supporting smoking harm reduction efforts.

Correlates of using E-cigarettes with high nicotine concentrations among U.S. adults who exclusively vape E-cigarettes or dual use with cigarettes

BACKGROUND

Identifying the correlates of using e-cigarettes with high nicotine concentrations in exclusive and dual-using vapers can elucidate which subpopulations might be most impacted by e-cigarette regulatory activities related to nicotine concentration.

METHODS

Data are drawn from Wave 5 (December 2018-November 2019) of the Population Assessment of Tobacco and Health (PATH) study. Self-reported nicotine concentration was grouped as high (5.0 %+), moderate (1.8-4.9 %), low (0.1-1.7 %), 0 %, and "I don't know." Multivariable logistic regressions estimated associations of sociodemographic factors, tobacco use status, and e-cigarette use patterns of high nicotine concentration vs. other nicotine levels, stratified by current exclusive e-cigarette use and dual use of e-cigarettes and cigarettes.

RESULTS

In the study samples (exclusive e-cigarette use [n = 1,755], dual-use [n = 1,200]), higher proportions of exclusive e-cigarette users reported using high nicotine concentrations than dual users (18.3 % vs. 8.6 %). Among exclusive e-cigarette users, never vs. former smokers and daily (vs. someday) e-cigarette users were more likely to use high vs. low nicotine. In both exclusive and dual users, younger (vs. older) adults were more likely to report using high nicotine concentration e-cigarettes than most other nicotine levels. Current dual users who did vs. did not report using e-cigarettes to quit smoking had higher odds of using high vs. 0 % nicotine concentrations.

CONCLUSIONS

High-nicotine e-cigarette use might be elevated in subpopulations that face greater risks for vaping (e.g., never smokers, young adults) than groups who benefit from the potential harm reduction. Regulatory restrictions on high-nicotine products may selectively affect some subgroups adversely impacted by vaping.

Association of cigarette and electronic cigarette use patterns with all-cause mortality: A national cohort study of 145,390 US adults

OBJECTIVE

While e-cigarette use is associated with adverse cardiopulmonary health effects, the mortality risks associated with e-cigarette use alone and combined with smoking remain unexamined.

METHODS

Data between 2014 and 2018 were obtained from the National Health Interview Survey (NHIS), an annual cross-sectional survey of US adults. All-cause mortality and date of death were obtained via linkage of the NHIS to the National Death Index through December 31, 2019. A 6-category composite cigarette (never, former, current) and e-cigarette (current, non-current) exposure variable was created. We examined the association of cigarette and e-cigarette use patterns with all-cause mortality using adjusted Cox models.

RESULTS

Among 145,390 participants (79,294 women [51.5%]; 60,560 aged 18-44 [47.4%]), 5220 deaths were observed over a median follow-up of 3.5 years (508,545 total person-years). Dual use of cigarettes and e-cigarettes was associated with higher mortality risk compared with non-current e-cigarette use in combination with never smoking (hazard ratio [HR] 2.44; 95% CI, 1.90-3.13) and had a risk that did not differ from current exclusive smoking (HR, 1.06; 95% CI, 0.83-1.37). Current e-cigarette use in combination with former smoking was associated with a lower mortality risk than current exclusive cigarette smoking (HR 0.64; 95% CI, 0.41-0.99).

CONCLUSIONS

The addition of e-cigarette use to smoking does not reduce mortality risk compared with exclusive smoking. However, transitioning completely from cigarettes to e-cigarettes may be associated with mortality risk reduction. Further research is needed to verify these findings in larger cohorts and over longer periods of follow-up.

Insomnia and parasomnia induced by validated smoking cessation pharmacotherapies and electronic cigarettes: a network meta-analysis

We aim to assess the relationship between validated smoking cessation pharmacotherapies and electronic cigarettes (e-cigarettes) and insomnia and parasomnia using a systematic review and a network meta-analysis. A systematic search was performed until August 2022 in the following databases: PUBMED, COCHRANE, CLINICALTRIAL. Randomized controlled studies against placebo or validated therapeutic smoking cessation methods and e-cigarettes in adult smokers without unstable or psychiatric comorbidity were included. The primary outcome was the presence of "insomnia" and "parasomnia." A total of 1261 studies were selected. Thirty-seven studies were included in the quantitative analysis (34 for insomnia and 23 for parasomnia). The reported interventions were varenicline (23 studies), nicotine replacement therapy (NRT, 10 studies), bupropion (15 studies). No studies on e-cigarettes were included. Bayesian analyses found that insomnia and parasomnia are more frequent with smoking cessation therapies than placebo except for bupropion. Insomnia was less frequent with nicotine substitutes but more frequent with bupropion than the over pharmacotherapies. Parasomnia are less frequent with bupropion but more frequent with varenicline than the over pharmacotherapies. Validated smoking cessation pharmacotherapies can induce sleep disturbances with different degrees of frequency. Our network meta-analysis shows a more favorable profile of nicotine substitutes for insomnia and bupropion for parasomnia. It seems essential to systematize the assessment of sleep disturbances in the initiation of smoking cessation treatment. This could help professionals to personalize the choice of treatment according to sleep parameters of each patient. Considering co-addictions, broadening the populations studied and standardizing the measurement are additional avenues for future research.

Managing a policy paradox? Responses to textual warning labels on E-cigarette advertisements among U.S. national samples of youth overall and adults who smoke or vape

CONTEXT

Current use and potential future uptake of e-cigarettes among youth remain public health concerns in the U.S., even as people who smoke combustible cigarettes could benefit from switching completely to e-cigarettes. The U.S. Food and Drug Administration (FDA) is considering alternative warning messages, but warnings that discourage youth from use may also deter people who smoke from switching. This study tests ten pre-registered hypotheses on effects of warning messages with national samples of youth overall and adults who smoke and/or vape.

METHODS

NORC recruited 1639 adults (ages 18+) who smoke, vape, or use both products, from their probability-sampled AmeriSpeak Panel and augmented their AmeriSpeak Teen Panel with Lucid's nonprobability opt-in panel to recruit 1217 youth (ages 14-17) to participate in a web-based survey experiment. We randomly assigned respondents to view one of five warning label conditions and respond to measures of their e-cigarette risk beliefs, willingness to use e-cigarettes, and (among people who smoke or vape) considerations to quit these products.

FINDINGS

Relative to the current FDA warning about nicotine, warning messages about the harms of e-cigarette use for youth brain development did not influence risk beliefs or reduce willingness to use these products among youth. Brain development warning messages did increase beliefs about these harms among adults but did not increase quit considerations among people who vape, relative to the FDA warning. Warning messages with information about chemical constituents of vaping products and the harm of these chemicals produced higher e-cigarette quit considerations than did the FDA warning among adults who vape.

CONCLUSION

Potential alternative warning label messages were largely ineffective relative to the current FDA warning about nicotine, though limited evidence suggests some potential for chemical + harm messaging to encourage people who use both e-cigarettes and cigarettes to consider quitting both.

Examining Perceptions of Uncertain Language in Potential E-Cigarette Warning Labels: Results from 16 Focus Groups with Adult Tobacco Users and Youth

E-cigarette use among youth presents a public health risk. Yet, cigarette smokers who substantially reduce their smoking or switch completely from traditional combustible cigarettes could benefit. As science about e-cigarettes is continually emerging, any potential warnings are likely to contain uncertain language. Hedged verbiage may impact decision making. To assess reactions, we conducted 16 online focus groups; 8 with youth (n = 32, grouped by gender and by vaping experience) and 8 with adult tobacco users (n = 37, grouped by smokers, dual users of e-cigarettes and cigarettes, and former smokers who switched to e-cigarettes). Each focus group viewed and discussed 8 potential warnings messages. We conducted an inductive thematic analysis of the reactions to warning messages that contain uncertain language. Respondents' reactions were often negative, but varied based on specific usages of uncertainty, existing beliefs about uncertainty in law and science, and smoking/vaping use patterns that supported the use of uncertainty related to e-cigarettes. Many youth (and some adults) believed that uncertain language enabled audiences to minimize the likelihood of harm or interpreted it as meaning there are both healthy and unhealthy e-cigarettes. This qualitative study provides evidence that the use of types of uncertain language, the frequency of that use, and/or the selection of particular words in warnings, might not achieve the intended public health aims of increasing understanding of risk, deterring youth uptake, and/or facilitating a substantial switch from cigarettes. The use of certain types of uncertain language appears to have significant potential to bring unintended consequences. Suggestions for research and policy are included.

Harm perceptions of vaping nicotine relative to cigarette smoking among sexual and gender minority young adults

INTRODUCTION

To address gaps in existing research, the current study used a mixed-methods approach to describe, contextualise and understand harm perceptions of vaping nicotine relative to cigarette smoking and associations with nicotine and tobacco (NT) use among young adults who identify their genders and sexualities in ways that classify them as sexual and gender minorities (SGM).

METHODS

Results are based on cross-sectional surveys and online qualitative interviews with 98 SGM young adults (18-25 years old) in California's San Francisco Bay Area who currently or formerly used combustible tobacco. We generated a measure assessing participants' relative harm perceptions of e-cigarette use versus cigarette smoking and identified those who perceived cigarette smoking as more harmful than e-cigarette use compared to those who perceived it to be equally or less harmful.

RESULTS

We found that relative harm perceptions of cigarette smoking versus e-cigarette use are likely related to much uncertainty and confusion about the harms of e-cigarette use. Moreover, findings illustrate that public health messages regarding the risks of e-cigarette use may have unintended consequences of increasing cigarette use to replace e-cigarette use for some SGM young adults, a practice that is incongruent with scientific evidence demonstrating that cigarettes and other combustible tobacco products are riskier than e-cigarettes and other forms of NT use.

DISCUSSION AND CONCLUSIONS

Results suggest the need for evidence-based, clear, and direct messaging about the relative harms of cigarettes versus e-cigarettes to reduce NT-related inequities in SGM populations.

Context matters: Neural processing of food-flavored e-cigarettes and the influence of smoking

E-cigarettes are harmful, addictive, and popular. In e-cigarettes, nicotine is often paired with food-flavors. How this pairing of nicotine and food cues influences neural processing warrants investigation, as in smokers, both types of cues activate similar brain regions. Additionally, while most e-cigarettes are sweet, savory e-cigarettes are seemingly absent, although savory flavors are commonly liked in food. To understand how smoking status and type of flavor modulate reactions to food-flavored e-cigarettes, in comparison to actual food, neural and subjective responses to food odors were measured in a 2 (sweet vs. savory odor) x2 (food vs. e-cigarette context) x2 (smokers vs. non-smokers) design in 22 occasional/light smokers and 25 non-smokers. During fMRI scanning, participants were exposed to sweet and savory odors and pictures creating the two contexts. Liking and wanting were repeatedly measured on a 100-unit visual-analogue-scale. Results show that sweet e-cigarettes were liked (Δ = 14.2 ± 1.7) and wanted (Δ = 39.5 ± 3.1) more than savory e-cigarettes, and their cues activated the anterior cingulate more (cluster-level qFDR = 0.003). Further, we observed context-dependent variations in insula response to odors (cluster-level qFDR = 0.023, and = 0.030). Savory odors in an e-cigarette context were wanted less than the same odors in a food-context (Δ = 32.8 ± 3.1). Smokers and non-smokers reacted similarly to flavored product cues. Our results indicate that the principles of flavor preference in food cannot directly be applied to e-cigarettes and that it is challenging to design sweet and savory e-cigarettes to appeal to smokers only.

Optimal Taxation of Cigarettes and E-Cigarettes: Principles for Taxing Reduced-Harm Tobacco Products

As the tax base for traditional tobacco excise taxes continues to erode, policymakers have growing interest to expand taxation to novel and reduced-risk tobacco products. Chief among the latter are electronic nicotine delivery systems (ENDS; commonly known as e-cigarettes), although other reduced-risk tobacco products such as heated tobacco and smokeless tobacco products are also being considered for taxation. There are many possible rationales for taxing such products: to raise revenue, to correct for health externalities, to improve public health, to correct for internalities caused by irrationality or misinformation, and to redistribute income. Although each rationale leads to a different objective function, the conclusions regarding relative tax rates are largely the same. The relatively higher price elasticity of demand for e-cigarettes (compared to cigarettes) and the lower marginal harms from use imply in each case that taxes on e-cigarettes and other harm-reduced products should be relatively lower, and likely much lower, than those on cigarettes. Additional considerations concerning the policy goal of discouraging use of any tobacco product by youth are discussed as well.

Influence of Disclosed and Undisclosed Funding Sources in Tobacco Harm Reduction Discourse: A Social Network Analysis

INTRODUCTION

Tobacco harm reduction (THR) discourse has been divisive for the tobacco control community, partially because it sometimes aligns public health and tobacco industry interests. Industry funding is contentious as it influences study outcomes, and is not always disclosed in scientific publications. This study examines the role of disclosed and undisclosed industry support on THR publications via social network analysis.

METHODS

We reviewed 826 English-language manuscripts (1992-2016) to determine disclosed and undisclosed industry (pharmaceutical, tobacco, and e-cigarette) and non-industry (including government) support received by 1405 authors. We used social network analysis to identify the most influential authors in THR discourse by assessing the number of their collaborators on publications, the frequency of connecting other authors in the network, and tendency to form groups based on the presence of sponsorship disclosures, sources of funding, and THR stance.

RESULTS

About 284 (20%) out of 1405 authors were supported by industry. Industry-sponsored authors were more central and influential in the network: with twice as many publications (Median = 4), 1.25 as many collaborators on publications (Median = 5), and higher likelihood of connecting other authors and thus having more influence in the network, compared to non-industry-sponsored authors. E-cigarette industry-sponsored authors had the strongest association with undisclosed industry support.

CONCLUSIONS

Authors with industry support exerted a stronger influence on the THR scientific discourse than non-industry-supported authors. Journals should continue adhering to strict policies requiring conflicts of interest disclosures. An increase in public health spending on tobacco control research may be necessary to achieve funding parity.

The smoking and vaping model, A user-friendly model for examining the country-specific impact of nicotine VAPING product use: application to Germany

BACKGROUND

Simulation models play an increasingly important role in tobacco control. Models examining the impact of nicotine vaping products (NVPs) and smoking tend to be highly specialized and inaccessible. We present the Smoking and Vaping Model (SAVM),a user-friendly cohort-based simulation model, adaptable to any country, that projects the public health impact of smokers switching to NVPs.

METHODS

SAVM compares two scenarios. The No-NVP scenario projects smoking rates in the absence of NVPs using population projections, deaths rates, life expectancy, and smoking prevalence. The NVP scenario models vaping prevalence and its impact on smoking once NVPs became popular. NVP use impact is estimated as the difference in smoking- and vaping-attributable deaths (SVADs) and life-years lost (LYLs) between the No-NVP and NVP scenarios. We illustrate SAVM's adaptation to the German adult ages 18+ population, the Germany-SAVM by adjusting the model using population, mortality, smoking and NVP use data.

RESULTS

Assuming that the excess NVP mortality risk is 5% that of smoking, Germany-SAVM projected 4.7 million LYLs and almost 300,000 SVADs averted associated with NVP use from 2012 to 2060. Increasing the excess NVP mortality risk to 40% with other rates constant resulted in averted 2.8 million LYLs and 200,000 SVADs during the same period.

CONCLUSIONS

SAVM enables non-modelers, policymakers, and other stakeholders to analyze the potential population health effects of NVP use and public health interventions.

Racial and ethnic disparities in biomarkers of exposure and potential harm among U.S. adult exclusive e-cigarette users: 2013-2019

OBJECTIVE

Provide evidence on racial and ethnic differences in biomarkers of exposure from rising e-cigarette use among U.S. adults.

METHODS

Data were drawn from Waves 1-5 of the Population Assessment of Tobacco and Health study (September 2013-November 2019). Differences in biomarkers of exposure and potential harm (BOE/BoPH) across non-Hispanic (NH)-Whites, NH Blacks, Hispanic/Latinos, and NH others were examined using generalized estimation equations.

RESULTS

Among exclusive e-cigarette users, mean concentrations of BOEs/BoPHs were not significantly different across NH Blacks (n=97), NH others (n=122), and NH Whites (n=1062), after adjustment by wave, age, sex, education, exposure to the secondhand smoke, and the number of recent puffs. Compared to NH Whites, Hispanics (n=151) had lower concentrations of nicotine equivalents (0.5[0.2-1.7] vs. 15.5 [12.5-19.1] nmol/mg creatinine, p<.0001), cotinine (33.4[9.7-114.7] vs. 1008.3 [808.3-1257.9] ng/mg creatinine, p<.0001), and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) (2.6[1.5-4.4] vs. 5.7 [4.9-6.6] pg/mg creatinine, p=.004), but similar concentrations of BOEs for heavy metals, polycyclic aromatic hydrocarbons, volatile organic compounds, and oxidative stress. Differences between Hispanics and NH Whites are expected, given different e-cigarette use profiles. Specifically, Hispanics were less likely to be daily vapers (49.4[35.1-63.8]% vs 81.3[77.7-84.5]%, p<.0001) and nicotine e-cigarette users (72.7 [64.0-79.9]% vs. 89.2 [86.4-91.5]%, p=.0002] and reported a lower number of recent puffs (mean[standard error]=16.7[3.6] vs. 28.6[2.0], p=.02] than their NH-White counterparts. Hispanic vapers were also less likely than NH Whites to have previously smoked cigarettes (49.7 [37.2-62.3]% vs. 88.5 [84.7-91.5]%, p<.0001]).

CONCLUSIONS

Hispanic vapers exhibited lower exposure to nicotine metabolites and carcinogens than their non-Hispanic White counterparts. The harm reduction potential from e-cigarette use are likely to be realized across diverse racial and ethnic groups.

Examination of the impact of myblu electronic nicotine delivery system e-liquid nicotine strength on self-reported measures of dependence

BACKGROUND

Greater nicotine delivery is associated with higher nicotine concentrations in electronic nicotine delivery system (ENDS) liquids. However, there is a current debate as to whether this leads to increased dependence and mitigates ENDS public health potential.

METHODS

Self-reported dependence among users of myblu ENDS containing different nicotine concentrations was examined with data from a multiwave cross-sectional survey of US young adults and adults. Questions examined responses related to dependence measures and participants' most often used myblu ENDS nicotine concentration (low: 0%, 1% and 1.2%; medium: 2%, 2.4% and 2.5%; or high: 3.6% and 4%).

RESULTS

A global general linear model using nicotine concentration, age and days myblu that was used in the past 30 revealed a significant difference in PROMIS scores among nicotine concentration groups (F = 4.07, p = 0.02). However, pairwise comparisons to examine which specific groups differed significantly from others showed no significant differences. Logistic regression demonstrated that strong past 30-day cravings to use myblu among participants using high or medium nicotine concentrations were not significantly different from those using a low concentration (ORs 0.66 [0.42, 1.03], p = 0.07 and 0.95 [0.49, 1.82], p = 0.98, respectively). Time to daily first use for high or medium nicotine concentration users was not significantly different from those using a low concentration (ORs 0.89 [0.70, 1.14], p = 0.35 and 0.84 [0.57, 1.25], p = 0.40, respectively).

CONCLUSIONS

Use of myblu ENDS with different nicotine concentrations is not associated with differing levels of dependence. Our findings contradict the notion that high ENDS e-liquid nicotine levels generate increased dependence.

Implications of nicotine vaping products for tobacco control in ASEAN low-income and middle-income countries: in-depth interviews with experts from the region

OBJECTIVES

The use of nicotine vaping products (NVPs) has increased in low-income and middle-income countries (LMICs) in the Association of Southeast Asian Nations (ASEAN) region; however, it is uncertain what implications the presence and use of NVPs have for tobacco control.

DESIGN

In-depth interviews were conducted to explore ASEAN tobacco control experts' (n=11) views on the rise of NVP use in ASEAN LMICs, current NVP policies, the potential harm reduction and smoking cessation utilities of these devices, and what implications they may have for tobacco control. Data were analysed using inductive, reflexive thematic analysis.

RESULTS

Five themes emerged: (1) NVPs threaten tobacco control in ASEAN LMICs; (2) commercial factors influence youth appeal and access: product attributes, marketing, supply chains; (3) opposition to the smoking cessation and harm reduction utilities of NVPs; (4) policies are inconsistent and fragmented in the region; and (5) tobacco industry power and tactics have been used to capture NVP markets.

CONCLUSIONS

ASEAN tobacco control experts believe that NVPs pose a threat to youth and non-smokers in LMICs in the region, largely because of tobacco industry NVP marketing activities. They do not support the use of NVPs for smoking cessation or harm reduction and call for more restrictions and consistent policy enforcement across the region to protect young people, while also cautiously recognising that use of NVPs may have some benefits for smokers.

How cigarette excise tax pass-through to prices responds to the uptake and evolution of e-cigarettes (ECs)

BACKGROUND

How excise taxes are passed through to prices determines whether tax policies will be effective in changing smoking behaviours. Though previous literature has documented that cigarette taxes are overly shifted to prices, there is limited evidence on how cigarette tax pass-through to prices is affected by the uptake and evolution of e-cigarettes (ECs) in the US market.

OBJECTIVE

This study investigates how cigarette excise tax pass-through rate varied by price levels (the 25th, 50th, and 75th percentile prices) and the uptake and evolution of ECs.

METHODS

Tax pass-through rates were assessed using ordinary least squares regressions while controlling for state, year and month fixed effects. Different trends were then tested for the pre-EC uptake era (2006-2011), EC uptake era (2012-2016) and the evolution of nicotine salt-based ECs era (2017 and later).

FINDINGS

Cigarette excise taxes were fully shifted to the 25th and 50th percentile prices and overly shifted to the 75th percentile prices at a 1:1.1 rate. While cigarette excise taxes had a continuous impact on raising prices, the tax pass-through rates were lower for lower priced cigarettes, and states imposed lower taxes.

CONCLUSIONS

Continuing to raise cigarette taxes may be needed to create financial incentives to encourage people who smoke to switch to ECs. In addition, continuing to raise cigarette taxes and additional pricing policies such as price promotion restrictions are needed to increase retail prices and reduce price minimisation opportunities.

Assessing the impact of protonating acid combinations in e-cigarette liquids: a randomised, crossover study on nicotine pharmacokinetics

The addition of protonating acids to e-cigarette liquid formulations (e-liquids) enhances nicotine bioavailability in e-cigarette use. However, little is known about the impact of different combinations of protonating acid on nicotine pharmacokinetics. The objectives of this study were to compare pharmacokinetics of nicotine absorption following use of a closed-system e-cigarette, containing e-liquids with two different nicotine levels and with different ratios of three common protonating acids-lactic, benzoic and levulinic. In a randomised, controlled, crossover study, nicotine pharmacokinetics and product liking were assessed for prototype e-liquids used in a Vuse e-cigarette containing either 3.5% or 5% nicotine and varying ratios of lactic, benzoic and/or levulinic acid. During an 8-day confinement period, 32 healthy adult current cigarette smokers/e-cigarette dual users used a single study e-liquid each day during 10-min fixed and ad libitum use periods after overnight nicotine abstinence. For most comparisons, Cmax and AUC0-60 following both fixed and ad libitum puffing were significantly higher for e-liquids containing 5% nicotine compared with 3.5% nicotine. However, Cmax and AUC0-60 were not statistically different for 5% nicotine e-liquids containing varying ratios of lactic, levulinic and benzoic acid when compared to an e-liquid containing lactic acid only. Mean scores for product liking were similar for all e-liquid formulations assessed, regardless of nicotine concentration, acid content, and whether the product was used in a fixed or ad libitum puffing regimen. While e-liquid nicotine concentration significantly affected users' nicotine uptake, the different combinations of benzoic, levulinic and lactic acid in the e-liquids assessed had limited impact on nicotine pharmacokinetics and product liking scores.

Predicting the long-term effects of electronic cigarette use on population health: a systematic review of modelling studies

OBJECTIVE

To systematically review and synthesise the findings of modelling studies on the population impacts of e-cigarette use and to identify potential gaps requiring future investigation.

DATA SOURCE AND STUDY SELECTION

Four databases were searched for modelling studies of e-cigarette use on population health published between 2010 and 2023. A total of 32 studies were included.

DATA EXTRACTION

Data on study characteristics, model attributes and estimates of population impacts including health outcomes and smoking prevalence were extracted from each article. The findings were synthesised narratively.

DATA SYNTHESIS

The introduction of e-cigarettes was predicted to lead to decreased smoking-related mortality, increased quality-adjusted life-years and reduced health system costs in 29 studies. Seventeen studies predicted a lower prevalence of cigarette smoking. Models that predicted negative population impacts assumed very high e-cigarette initiation rates among non-smokers and that e-cigarette use would discourage smoking cessation by a large margin. The majority of the studies were based on US population data and few studies included factors other than smoking status, such as jurisdictional tobacco control policies or social influence.

CONCLUSIONS

A population increase in e-cigarette use may result in lower smoking prevalence and reduced burden of disease in the long run, especially if their use can be restricted to assisting smoking cessation. Given the assumption-dependent nature of modelling outcomes, future modelling studies should consider incorporating different policy options in their projection exercises, using shorter time horizons and expanding their modelling to low-income and middle-income countries where smoking rates remain relatively high.

Vaping and socioeconomic inequalities in smoking cessation and relapse: a longitudinal analysis of the UK Household Longitudinal Study

BACKGROUND

Smoking is a key cause of socioeconomic health inequalities. Vaping is considered less harmful than smoking and has become a popular smoking cessation aid, and therefore has potential to reduce inequalities in smoking.

METHODS

We used longitudinal data from 25 102 participants in waves 8-10 (2016 to early 2020) of the UK Household Longitudinal Study to examine how vaping affects socioeconomic inequalities in smoking cessation and relapse. Marginal structural models were used to investigate whether vaping mediates or moderates associations between educational attainment and smoking cessation and relapse over time. Multiple imputation and weights were used to adjust for missing data.

RESULTS

Respondents without degrees were less likely to stop smoking than those with a degree (OR: 0.65; 95% CI 0.54-0.77), and more likely to relapse (OR: 1.74; 95% CI 1.37-2.22), but this inequality in smoking cessation was not present among regular vapers (OR: 0.99; 95% CI 0.54-1.82). Sensitivity analyses suggested that this finding did not hold when comparing those with or without any qualifications. Inequalities in smoking relapse did not clearly differ by vaping status.

CONCLUSIONS

Vaping may be especially helpful as a cessation aid for smokers without degree level education and therefore may help reduce inequalities in smoking. Nevertheless, other supports or aids may be needed to reach the most disadvantaged (ie, those with no qualifications) and to help people avoid relapse after cessation, though we did not find clear evidence suggesting that vaping would increase inequalities in relapse.

Using the Past to Understand the Future of U.S. and Global Smoking Disparities: A Birth Cohort Perspective

U.S. smoking-related disparities persist, but data evaluating how smoking patterns across diverse populations have changed by birth cohort are lacking. Worldwide, smoking continues to exact harm, especially to low- and middle-income nations with less historical data for smoking analyses. The Cancer Intervention and Surveillance Modeling Network (CISNET) Lung Working Group previously generated smoking histories for the whole U.S. population using an age, period, and birth cohort (APC) methodological framework. These inputs have been used in numerous models to simulate future patterns of smoking and to evaluate the potential impact of policies. However, the absence of detailed model-ready inputs on smoking behaviors for diverse U.S. populations has been a barrier to research evaluating future trends in smoking-related disparities or the projected impacts of policies across sociodemographic groups. This supplement issue provides new estimates of smoking behaviors with detailed historical data by race/ethnicity, educational attainment, family income, and for each of the 50 U.S. states and Washington, DC. All-cause mortality relative risks associated with smoking by race/ethnicity and educational attainment are also available for the first time. Finally, the supplement issue presents comprehensive smoking histories for Brazil, demonstrating the application of this methodology to resource-limited settings. Collectively, these data aim to offer insight into future U.S. and global smoking disparities and accelerate research on tobacco control policies that advance health equity. This effort will allow tobacco simulation models to account comprehensively for population diversity, thereby enabling researchers to develop more sophisticated analyses of tobacco use and control interventions.

Exploring the gateway hypothesis of e-cigarettes and tobacco: a prospective replication study among adolescents in the Netherlands and Flanders

BACKGROUND

Studies demonstrated that adolescent e-cigarette use is associated with subsequent tobacco smoking, commonly referred to as the gateway effect. However, most studies only investigated gateways from e-cigarettes to tobacco smoking. This study replicates a cornerstone study revealing a positive association between both adolescent e-cigarette use and subsequent tobacco use; and tobacco and subsequent e-cigarette use in the Netherlands and Flanders.

DESIGN

The longitudinal design included baseline (n=2839) and 6-month (n=1276) and 12-month (n=1025) follow-up surveys among a school-based cohort (mean age: 13.62). Ten high schools were recruited as a convenience sample. The analyses involved (1) associations of baseline e-cigarette use and subsequent tobacco smoking among never smokers; (2) associations of e-cigarette use frequency at baseline and tobacco smoking frequency at follow-up; and (3) the association of baseline tobacco smoking and subsequent e-cigarette use among non-users of e-cigarettes.

FINDINGS

Consistent with prior findings, baseline e-cigarette use was associated with higher odds of tobacco smoking at 6-month (OR=1.89; 95% CI 1.05 to 3.37) and 12-month (OR=5.63; 95% CI 3.04 to 10.42) follow-ups. More frequent use of e-cigarettes at baseline was associated with more frequent smoking at follow-ups. Baseline tobacco smoking was associated with subsequent e-cigarette use (OR=3.10; 95% CI 1.58 to 6.06 at both follow-ups).

CONCLUSION

Our study replicated the positive relation between e-cigarette use and tobacco smoking in both directions for adolescents. This may mean that the gateway works in two directions, that e-cigarette and tobacco use share common risk factors, or that both mechanisms apply.

A Pandemic Treaty: Learning From the Framework Convention on Tobacco Control

The World Health Organization recently began developing a "pandemic treaty" in response to the perceived failures of the global COVID-19 response. The Framework Convention on Tobacco Control, which obligates members to certain global standards in tobacco control, is an example of a global public health agreement that may be used as a model for the pandemic treaty. Several challenges related to the convention, many from the tobacco industry itself, must be addressed if it is to be used as a prototype for a pandemic agreement. These include harm reduction policies, private-sector involvement, and its impact in low- and middle-income countries. A pandemic treaty may encounter similar challenges faced by the Framework Convention on Tobacco Control, particularly from industry groups with financial interests related to infectious disease control and prevention. Addressing challenges at the outset may facilitate the development and implementation of a more robust international instrument.

The effectiveness of a motivational text-messaging program for smoking cessation after coronary angioplasty: a quasi-experimental study

OBJECTIVE

Smoking is an important risk factor of coronary artery stenosis after angioplasty. Therefore, this investigation aimed to determine the effectiveness of a motivational text-messaging program for smoking cessation after coronary angioplasty. This quasi-experimental study was conducted on 100 patients after angioplasty. The patients were divided randomly into two intervention and control groups. The intervention group received 32 text messages about smoking cessation for 2 months. The control group received only routine training. The primary and secondary outcomes were success and self-efficacy in quitting smoking cigarettes, respectively. Both groups filled out the related questionnaires before and after the intervention. The data were analyzed using SPSS software version 22 and Chi-square tests, independent t-test, and paired t-test. P < 0.05 was considered significant.

RESULTS

Success in quitting cigarette smoking was significantly higher in the intervention group (n = 29, 61.7%) compared to the control group (n = 2, 4.3%) (p < 0.001). Moreover, after the intervention, the mean score of self-efficacy in the intervention group (11.01 ± 44.75) was significantly higher than the control group (6.51 ± 3.11) and also higher than before the intervention (5.51 ± 2.44) (P˂0.001). The motivational text-messaging program can improve self-efficacy and success in smoking cessation in patients after coronary angioplasty.

The Australia Smoking and Vaping Model: The Potential Impact of Increasing Access to Nicotine Vaping Products

BACKGROUND

We model the potential impact of relaxing current nicotine vaping product (NVP) restrictions on public health in Australia.

AIMS AND METHODS

A Restricted NVP Scenario was first developed to project current smoking and vaping rates, where a U.S. smoking model was calibrated to recent Australian trends. To model less restrictive NVP policies, a Permissive NVP Scenario applied rates of switching from smoking to vaping, initiation into NVP and cigarette use, and cessation from smoking and vaping based on U.S. trends. The model measures vaping risk relative to the excess mortality rate of smoking. The public health impacts are measured as the difference between smoking- and vaping-attributable deaths (SVADs) and life years lost (LYLs) in the Restricted and Permissive NVP Scenarios. Sensitivity analysis is conducted regarding the NVP excess risk and other factors.

RESULTS

Assuming an NVP excess risk of 5% that of smoking, 104.2 thousand SVADs (7.7% reduction) and 2.05 million LYLs (17.3% reduction) are averted during 2017-2080 in the Permissive NVP Scenario compared to the Restricted NVP Scenario. Assuming 40% NVP excess risk, 70 thousand SVADs and 1.2 million LYLs are averted. The impact is sensitive to the rate at which smokers switch to NVPs and quit smoking, and relatively insensitive to the smoking initiation and NVP initiation and cessation rates.

CONCLUSIONS

The model suggests the potential for public health gains to be achieved by relaxing NVP access regulations. However, the model would benefit from better information regarding the impact of NVPs on smoking under a relaxation of current restrictions.

IMPLICATIONS

Australia has implemented a strong array of cigarette-oriented policies, but has restricted access to NVPs. The Smoking and Vaping Model offers a framework for modeling hypothetical policy scenarios. The Australian model shows the potential for public health gains by maintaining cigarette-oriented policies while relaxing the current restrictive NVP policy. Modeling results under a permissive NVP policy are particularly sensitive to the estimated rates of smoking cessation and switching to vaping, which are not well established and will likely depend on past and future cigarette-oriented policies and the specific NVP policies implemented in Australia.

Using Regulatory Stances to See All the Commercial Determinants of Health

Policy Points The commercial determinants of health (CDoH) concept, which currently focuses on markets that harm health, should be expanded to refer to the interface between commerce and health, which can sometimes have positive public health consequences. The regulatory stances framework helps us classify public health preferences for regulating specific markets related to CDoH, based on the intended effects of regulations on market size. The regulatory stances a jurisdiction can adopt can be classified as ranging from prohibitionist through contractionist, permissive, and expansionist, to universalist. The regulatory stances framework increases the usefulness of the CDoH concept by expanding the conversation beyond negative determinants of health and providing a fuller view of the tools at the disposal of society to alter markets and improve health.

CONTEXT

The effects of commerce on the public health are omnipresent. The commercial determinants of health (CDoH) represent a burgeoning area of scholarly debate and activist policymaking to redress markets that adversely affect public health. The CDoH debate is a logical extension of the tobacco control movement, but, to its detriment, the CDoH conversation remains primarily focused policies and proposals that are analogous to historical tobacco control strategies.

METHODS

This paper argues that for the CDoH to develop further and broaden its appeal, it should expand to cover markets with conditional and positive impacts on health. To explain and order this conversation, a comparative framework for regulatory policy is introduced: the regulatory stances. The regulatory stances classify a regulatory policy based on the intended effect of policy on the size of a market in the future relative to the present.

FINDINGS

Some markets that interface between commerce and health do not inherently harm health. Regulatory policy toward these markets should be different in intent than regulatory policy for markets with negative health effects.

CONCLUSIONS

By using the regulatory stances framework to encompass markets that have positive or conditional effects on health as well as those that have adverse health effects, the CDoH conversation can shift away from the exclusive focus on strategies to shrink markets with adverse health impacts to consider a wider array of policy options.

E-Cigarette Markets and Policy Responses in Southeast Asia: A Scoping Review

BACKGROUND

The global e-cigarette market has proliferated and is increasingly dominated by transnational tobacco companies. While Southeast Asian countries have received relatively little attention in e-cigarette research, the region represents an area of potentially untapped growth for the industry. We review the e-cigarette situation in Southeast Asia in terms of the e-cigarette markets, advertising and promotion of e-cigarettes, reported health impacts of e-cigarette use, and policy responses in the region.

METHODS

We examined e-cigarette market data from the Euromonitor Global Market Information Database (GMID) Passport database, searched in the academic literature, grey literature and news archives for any reports or studies of e-cigarette related diseases or injuries, e-cigarette marketing, and e-cigarette policy responses in Southeast Asian countries, and browsed the websites of online e-cigarette retailers catering to the region's active e-cigarette markets.

RESULTS

In 2019, e-cigarettes were sold in six Southeast Asian markets with a total market value of $595 million, projected to grow to $766 million by 2023. E-commerce is a significant and growing sales channel in the region, with most of the popular or featured brands in online shops originating from China. Southeast Asian youth are targeted with a wide variety of flavours, trendy designs and point of sale promotions, and several e-cigarette related injuries and diseases have been reported in the region. Policy responses vary considerably between countries, ranging from strict bans to no or partial regulations.

CONCLUSION

Although Southeast Asia's e-cigarette market is relatively nascent, this is likely to change if transnationals invest more heavily in the region. Populous countries with weak e-cigarette regulations, notably Indonesia, Malaysia, Vietnam and the Philippines, are desirable targets for the transnationals. Regulatory action is needed to prevent e-cigarette use from becoming entrenched into these societies, especially among young people.

Association between the implementation of tobacco control policies and adolescent vaping in 44 lower-middle, upper-middle, and high-income countries

AIM

To (i) estimate the prevalence of adolescent vaping in 47 lower-middle, upper-middle and high-income countries, and (ii) test the association between implementation of World Health Organisation (WHO) tobacco control policies and adolescent e-cigarette use (also known as vaping) in 44 countries where implementation data were available.

DESIGN

Cross-sectional surveys.

SETTINGS

A total of 47 lower-middle, upper-middle and high-income countries.

PARTICIPANTS

A total of 151 960 adolescents (typically ages 13-15) who participated in WHO's Global Youth Tobacco Survey between 2015 and 2018.

MEASUREMENTS

Prevalence of past-30-day vaping and past 30-day frequent vaping (≥10 days) were estimated from the surveys. Data on the implementation of six tobacco control measures including monitoring, smoke-free policies, cessation programs, warning about the dangers of tobacco, advertising bans and taxation were taken from WHO's report on global tobacco epidemic.

FINDINGS

The overall weighted prevalence of adolescent vaping and frequent vaping in the past 30 days was 8.6% (95% CI, 8.3-8.9) and 1.7% (95% CI, 1.6-1.8), respectively. For five of WHO's policies (monitoring, smoking-free environment, cessation programs, health warning and advertising bans), their association with adolescent vaping was inconclusive because of large variation of their effects across countries. Higher tax on combustible tobacco products was associated with higher adolescent vaping (> = 75% tax vs < 25% tax; odds ratio = 2.58; 95% CI, 1.25-5.21).

CONCLUSION

In 47 lower-middle, upper-middle and high-income countries from 2015 to 2018, ~1 in 12 (8.6%) adolescents reported vaping in the past 30 days, but prevalence of frequent vaping was low (1 in 60; 1.7%). A higher tobacco tax was associated with higher adolescent vaping.

Regulating Gambling-Like Video Game Loot Boxes: a Public Health Framework Comparing Industry Self-Regulation, Existing National Legal Approaches, and Other Potential Approaches

Purpose of Review

Loot boxes are gambling-like monetisation mechanics in video games that are purchased for opportunities to obtain randomised in-game rewards. Gambling regulation is increasingly being informed by insights from public health. Despite conceptual similarities between loot boxes and gambling, there is much less international consensus on loot box regulation. Various approaches to regulating loot boxes are reviewed via a public health framework that highlights various trade-offs between individual liberties and harm prevention.

Recent Findings

Many countries have considered regulation, but as yet only a few countries have taken tangible actions. Existing regulatory approaches vary greatly. More restrictively, Belgium has effectively ‘banned’ paid loot boxes and prohibits their sale to both children and adults. In contrast, more liberally, China only requires disclosure of the probabilities of obtaining potential rewards to provide transparency and perhaps help players to make more informed purchasing decisions. Most other countries (e.g., the UK) have adopted a ‘wait-and-watch’ approach by neither regulating loot box sales nor providing any dedicated consumer protection response. Industry self-regulation has also been adopted, although this appears to elicit lower rates of compliance than comparable national legal regulation.

Summary

Many potential public health approaches to loot box regulation, such as expenditure limits or harm-reducing modifications to loot box design (e.g., fairer reward structures), deserve further attention. The compliance and clinical benefits of existing interventions (including varying degrees of regulation, as adopted by different countries, and industry self-regulation) should be further assessed. The current international variation in loot box regulation presents opportunities to compare the merits of different approaches over time.

TOBACCO USE DISORDER AND DUAL DISORDERS Joint statement by the Spanish Psychiatry Society and the Spanish Dual Disorders Society

Tobacco Use Disorder (TUD) is a health problem of the first order in the world population, affecting a vulnerable population, such as people with other mental disorders, whose morbidity and mortality are increased as a result.

A targeted approach to using e-cigarettes for harm reduction in adults

Smoking remains the leading preventable cause of death and disease in the US. While e-cigarettes (EC) are undeniably harmful when used by adolescents and nonsmokers, the perpetuation of the increasing negative perceptions of EC and widespread false belief that EC are equal or more harmful than combustible cigarettes (CC) represents a significant missed public health opportunity. EC have great potential to serve as a mechanism for smoking harm reduction among hard-to-treat populations of smokers who have failed to quit with currently available treatments. In this paper, we outline why we need to overcome the hostile EC research environment to explore the potential use of EC as a harm-reduction strategy in hard-to-treat populations.

Closing the gaps in tobacco endgame evidence: a scoping review

OBJECTIVE

Tobacco endgame policies aim to rapidly and permanently reduce smoking to minimal levels. We reviewed evidence syntheses for: (1) endgame policies, (2) evidence gaps, and (3) future research priorities.

DATA SOURCES

Guided by JBI scoping review methodology, we searched five databases (PubMed, CINAHL, Scopus, Embase and Web of Science) for evidence syntheses published in English since 1990 on 12 policies, and Google for publications from key national and international organisations. Reference lists of included publications were hand searched.

STUDY SELECTION

Two reviewers independently screened titles and abstracts. Inclusion criteria were broad to capture policy impacts (including unintended), feasibility, public and stakeholder acceptability and other aspects of policy implementation.

DATA EXTRACTION

We report the results according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews checklist.

DATA SYNTHESIS

Eight policies have progressed to evidence synthesis stage (49 publications): mandatory very low nicotine content (VLNC) standard (n=26); product standards to substantially reduce consumer appeal or remove the most toxic products from the market (n=1); moving consumers to reduced risk products (n=8); tobacco-free generation (n=4); ending sales (n=2); sinking lid (n=2); tax increases (n=7); and restrictions on tobacco retailers (n=10). Based on published evidence syntheses, the evidence base was most developed for a VLNC standard, with a wide range of evidence synthesised.

CONCLUSIONS

VLNC cigarettes have attracted the most attention, in terms of synthesised evidence. Additional focus on policies that reduce the availability of tobacco is warranted given these measures are being implemented in some jurisdictions.

Electronic cigarettes as a harm reduction strategy among patients with COPD: protocol for an open-label two arm randomized controlled pilot trial

BACKGROUND

Smoking cessation is the most effective means of slowing the decline of lung function associated with chronic obstructive pulmonary disease (COPD). While effective smoking cessation treatments are available, they are underutilized and nearly half of people with COPD continue to smoke. By addressing both nicotine and behavioral dependence, electronic cigarettes (EC) could help people with COPD reduce the harm of combustible cigarettes (CC) through reductions in number of Cigarettes per Day (CPD) or quitting CC completely. The purpose of this pilot study is to identify barriers and facilitators to the use of and assess the preliminary effectiveness of EC as a harm reduction strategy among people with COPD.

METHODS

In an open-label two-arm randomized controlled trial pilot study, 60 patients identified as smokers with a COPD diagnosis via electronic health records from a large urban health center are randomized in a 1:1 ratio to either standard care [counseling + nicotine replacement therapy (NRT)] or counseling + EC. The NRT arm will receive nicotine patches and nicotine lozenges for 12 weeks. The EC arm will receive EC for 12 weeks. Both cohorts will receive counseling from a licensed mental health counselor. Using ecological momentary assessment, participants will report their use of CC in both arms and EC use in the EC arm daily via text message. Primary outcomes will be feasibility and acceptability of intervention, and secondary outcomes will be reduction in CPD and change in COPD symptoms as measured by COPD Assessment Tool (CAT) score at 12-weeks. EC displacement of CC. To explore attitudes towards the use of EC as a harm-reduction strategy for patients with COPD, interviews will be performed with a sample of participants from both study arms.

DISCUSSION

Despite decades of availability of smoking cessation medications, nearly half of people with COPD still smoke. This study aims to address the unmet need for feasible and effective strategies for reducing CC use among those with COPD, which has the potential to significantly improve the health of people with COPD who smoke. Trial Registration ClinicalTrials.gov Identifier: NCT04465318.

Young Adults May Be Engaging in Risky Behaviors with their E-Cigarettes

E-cigarette use has significantly escalated among young adults in recent years. The purpose of the current study was to better understand alternative ways in which young adults use their e-cigarettes in situations where ad-lib use is prohibited. The current study is a secondary analysis to a parent study assessing facilitators and barriers for tobacco use among young adult military personnel. Ten focus groups were conducted with 83 Airmen at the end of their Technical (advanced) Training. Focus group discussions were transcribed and thematic analysis was used to determine trends related to risky e-cigarette use. Participants described using liquids with extremely high nicotine contents or using the e-cigarette so quickly and intensely that they could not stand up or became ill. Results highlight the ease by which individuals can make alterations to their e-cigarettes or their use behaviors, which could potentially increase their risk of nicotine poisoning.

Estimating the reduction in US mortality if cigarettes were largely replaced by e-cigarettes

BACKGROUND

Recent estimates indicated substantially replacing cigarettes by e-cigarettes would, during 2016-2100, reduce US deaths and life-years lost (millions) by 6.6 and 86.7 (Optimistic Scenario) and 1.6 and 20.8 (Pessimistic). To provide additional insight we use alternative modelling based on a shorter period (1991-2040), four main smoking-associated diseases, deaths aged 30-79 years, and a full product history. We consider variations in: assumed effective dose of e-cigarettes versus cigarettes (F); their relative quitting rate (Q); proportions smoking after 10 years (X); and initiation rate (I) of vaping, relative to smoking.

METHODS

We set F = 0.05, X = 5%, Q = 1.0 and I = 1.0 (Main Scenario) and F = 0.4, X = 10%, Q = 0.5 and I = 1.5 (Pessimistic Scenario). Sensitivity Analyses varied Main Scenario parameters singly; F from 0 to 0.4, X 0.01% to 15%, and Q and I 0.5 to 1.5. To allow comparison with prior work, individuals cannot be dual users, re-initiate, or switch except from cigarettes to e-cigarettes.

RESULTS

Main Scenario reductions were 2.52 and 26.23 million deaths and life-years lost; Pessimistic Scenario reductions were 0.76 and 8.31 million. These were less than previously, due to the more limited age-range and follow-up, and restriction to four diseases. Reductions in deaths (millions) varied most for X, from 3.22 (X = 0.01%) to 1.31 (X = 15%), and F, 2.74 (F = 0) to 1.35 (F = 0.4). Varying Q or I had little effect.

CONCLUSIONS

Substantial reductions in deaths and life-years lost were observed even under pessimistic assumptions. Estimates varied most for X and F. These findings supplement literature indicating e-cigarettes can importantly impact health challenges from smoking.

Study protocol: evaluation of the addictive potential of e-cigarettes (EVAPE): neurobiological, sociological, and epidemiological perspectives

BACKGROUND

Tobacco use is the largest preventable cause of diseases and deaths; reducing tobacco intake is, therefore, an urgent public health goal. In recent years, e-cigarettes have been marketed as a 'healthier' alternative to tobacco smoking, whilst product features have evolved tremendously in the meantime. A lively scientific debate has developed regarding the potential benefits and risks of e-cigarettes although, surprisingly, there are few studies investigating the addictive potential of nicotine-containing e-cigarettes. The present work comprises three work packages investigating the addictive potential of e-cigarettes from different perspectives: (1) the neurobiological addictive potential of e-cigarettes; (2) the experience and perception of dependence symptoms among users of e-cigarettes in a social context; and (3) the epidemiological perspective regarding factors influencing the potential for dependence.

METHODS

Work package I: the neurobiological study will investigate the key elements of addiction in e-cigarettes compared to tobacco cigarettes using neurobiological and neuropsychological correlates associated with craving, incentive motivation, cue reactivity and attentional bias. Work package II: the sociological study part examines self-reports on the experience and perception of dependence symptoms in a social context, using focus group interviews and the analysis of posts in online discussion forums on e-cigarettes. Work package III: the epidemiological study part focuses on tolerance development and the role of psychosocial and product factors by analyzing longitudinal data from the International Tobacco Control Policy Evaluation Project (ITC).

DISCUSSION

The present study offers a chosen mix of three methodological approaches, thereby comprehensively examining core symptoms of positive and negative reinforcement in addiction. Whether e-cigarettes are as reinforcing and addictive as combustible tobacco cigarettes is an important public health issue with implications for prevention and treatment programs.

TRIAL REGISTRATION

Work package I: Registered at clinicaltrials.gov/ct2/show/NCT04772014. Work package II: Registered at OSF Registries: https://osf.io/dxgya (2021, January 14).

Improving on estimates of the potential relative harm to health from using modern ENDS (vaping) compared to tobacco smoking

BACKGROUND

Although the harm to health from electronic nicotine delivery systems (ENDS) compared to smoked tobacco remains highly uncertain, society and governments still need to know the likely range of the relative harm to inform regulatory policies for ENDS and smoking.

METHODS

We identified biomarkers with specificity of association with different disease groupings e.g., volatile organic compound (VOCs) for chronic obstructive pulmonary disease; and tobacco-specific N´-nitrosamines (TSNAs) and polycyclic aromatic hydrocarbons (PAHs) for all cancers. We conducted a review of recent studies (post January 2017) that compared these biomarkers between people exclusively using ENDS and those exclusively smoking tobacco. The percentage differences in these biomarkers, weighted by study size and adjusted for acrolein from other sources, were used as a proxy for the assumed percentage difference in disease harm between ENDS and smoking. These relative differences were applied to previously modelled estimates of smoking-related health loss (in health-adjusted life-years; HALYs).

RESULTS

The respective relative biomarker levels (ENDS vs smoking) were: 28% for respiratory diseases (five results, three studies); 42% for cancers (five results, four studies); and 35% for cardiovascular (seven results, four studies). When integrated with the HALY impacts by disease, the overall harm to health from ENDS was estimated to be 33% that of smoking.

CONCLUSIONS

This analysis, suggests that the use of modern ENDS devices (vaping) could be a third as harmful to health as smoking in a high-income country setting. But this estimate is based on a limited number of biomarker studies and is best be considered a likely upper level of ENDS risk given potential biases in our method (i.e., the biomarkers used being correlated with more unaccounted for toxicants in smoking compared to with using ENDS).

Conceptual model for the evaluation of attractiveness, addictiveness and toxicity of tobacco and related products: The example of JUUL e-cigarettes

Many new tobacco and related products (nTRP) have emerged on the market, with unknown health risks. Here, we present a conceptual model containing the factors and relations between them that contribute to the nTRP's health effects. Factors that determine attractiveness, addictiveness and toxicity of nTRP were defined based on previous assessments, literature, and expert discussions. Our model will aid in identifying key risk factors contributing to increased risk of adverse health effects for a product in a qualitative manner. Additionally, it can gauge attractiveness for specific user groups, as a determinant for population prevalence of use. Our model can be used to identify aspects of nTRP that require attention for public information or product regulation. As an example, we applied this to JUUL, a popular e-cigarette in the US. Aspects of concern for JUUL are its attractive and discrete shape, user-friendly prefilled pods, flavors, high aerosol nicotine levels, and liquids containing nicotine salts instead of free-based nicotine. The addictiveness and especially attractiveness are sufficiently high to have a large potential impact on population health due to its contribution to use and hence exposure. Products and their use can change over time; therefore market research and monitoring are crucial.

Balancing Consideration of the Risks and Benefits of E-Cigarettes

The topic of e-cigarettes is controversial. Opponents focus on e-cigarettes' risks for young people, while supporters emphasize the potential for e-cigarettes to assist smokers in quitting smoking. Most US health organizations, media coverage, and policymakers have focused primarily on risks to youths. Because of their messaging, much of the public-including most smokers-now consider e-cigarette use as dangerous as or more dangerous than smoking. By contrast, the National Academies of Science, Engineering, and Medicine concluded that e-cigarette use is likely far less hazardous than smoking. Policies intended to reduce adolescent vaping may also reduce adult smokers' use of e-cigarettes in quit attempts. Because evidence indicates that e-cigarette use can increase the odds of quitting smoking, many scientists, including this essay's authors, encourage the health community, media, and policymakers to more carefully weigh vaping's potential to reduce adult smoking-attributable mortality. We review the health risks of e-cigarette use, the likelihood that vaping increases smoking cessation, concerns about youth vaping, and the need to balance valid concerns about risks to youths with the potential benefits of increasing adult smoking cessation.

Analytical methods for the identification of micro/nano metals in e-cigarette emission samples: a review

In this review, numerous analytical methods to quantify the heavy and trace elements emitted from electronic cigarettes, cigarettes liquid and atomizer. The selection of a method was dependent upon the purpose, e.g., quantification or identification of elements only. The introductory part of this review focuses on describing the importance of setting up an electronic cigarettes- associated safety profile. The review dealt with studies that assessed elements in sizes ranging from nano to micro. The formation of different degradation chemical substances as well as impurity trends can be indicated through chemical investigation of metals in electronic cigarettes. Some studies have been covered that show the uses and benefits of. It is noticeable from all the collected sources that the minerals emitted from the smoke of e- cigs do not constitute any significant damage, as the percentage is very small, with the exception of minerals that may be emitted from the components of the device after heating it if the components of the e- cig are of poor specifications, except in the case of long-term accumulation. For this reason, an electronic cigarette can help smokers to quit smoking tobacco and replace it with electronic cigarettes smoke with distinctive flavors.

A systematic review of randomized controlled trials and network meta-analysis of e-cigarettes for smoking cessation

AIM

E-cigarettes, or nicotine vaping products, are potential smoking cessation aids that provide both nicotine and behavioural substitution for combustible cigarette smoking. This review aims to compare the effectiveness of nicotine e-cigarettes for smoking cessation with licensed nicotine replacement therapies (NRT) and nicotine-free based control conditions by using network meta-analysis (NMA).

METHODS

We searched PubMed, Web of Science and PsycINFO for randomised controlled trials (RCTs) that allocated individuals to use nicotine e-cigarettes, compared to those that used licensed NRT (e.g., nicotine patches, nicotine gums, etc), or a nicotine-free control condition such as receiving placebo (nicotine-free) e-cigarettes or usual care. We only included studies of healthy individuals who smoked. Furthermore, we identified the latest Cochrane review on NRT and searched NRT trials that were published in similar periods as the e-cigarette trials we identified. NMA was conducted to compare the effect of e-cigarettes on cessation relative to NRT and control condition. Cochrane risk-of-bias tool for randomized trials Version 2 was used to access study bias.

RESULTS

For the e-cigarette trials, our initial search identified 4,717 studies and we included 7 trials for NMA after removal of duplicates, record screening and assessment of eligibility (Total N = 5,674). For NRT trials, our initial search identified 1,014 studies and we included 9 trials that satisfied our inclusion criteria (Total N = 6,080). Results from NMA indicated that participants assigned to use nicotine e-cigarettes were more likely to remain abstinent from smoking than those in the control condition (pooled Risk Ratio (RR) = 2.08, 97.5% CI = [1.39, 3.15]) and those who were assigned to use NRT (pooled RR = 1.49, 97.5% CI = [1.04, 2.14]. There was a moderate heterogeneity between studies (I2 = 42%). Most of the e-cigarette trials has moderate or high risk of bias.

CONCLUSION

Smokers assigned to use nicotine e-cigarettes were more likely to remain abstinent from smoking than those assigned to use licensed NRT, and both were more effective than usual care or placebo conditions. More high quality studies are required to ascertain the effect of e-cigarette on smoking cessation due to risk of bias in the included studies.

Thirteen-week nose-only inhalation exposures of propylene glycol aerosols in Sprague Dawley rats with a lung systems toxicology analysis

The objectives of this study were to increase PG exposure above concentrations tested by Suber et al. and use systems toxicology analysis of lung tissue to understand molecular events. Sprague Dawley rats were exposed to filtered air (sham), propylene glycol/water (PG/W; 90:10) or a propylene glycol/vegetable glycerin/water (PG/VG/W; 50:40:10) reference. The reference group was added at the high dose to observe any changes that might be associated with a carrier more in line with e-vapor products. Macroscopic examinations and terminal organ weights revealed no observations associated with exposure to PG/W or reference. Food consumption and body weights were unaffected by PG/W or reference when compared to sham. No exposure related alterations were observed in serum chemistry, hematology, coagulation, urinalysis or BALF cytology and clinical chemistry. Although clinical observations of dried red material around the nose in the high dose PG/W group were reported, histopathology showed no nasal hemorrhaging which was previously reported by Suber et al. Non-adverse PG/W and reference related findings of minimal mucous cell hyperplasia were noted in nasal cavity section II. No other exposure-related findings were noted in the primary or recovery necropsies. A systems toxicology analysis on lung tissue showed no statistically significant differentially expressed transcripts or proteins compared to the sham group. The endpoints measured from the PG/W high dose group did not differ significantly from those in the more common carrier PG/VG/W. As anticipated, exposure to PG aerosols was slightly irritating but well tolerated. Accordingly, the highest PG exposure (5 mg/L, 6 hrs/day) was regarded as the NOAEC, corresponding to a PG delivered dose of 1,152 mg/kg/day in rats.

Patterns of E-cigarette Use and Subsequent Cigarette Smoking Cessation Over 2 Years (2013/2014-2015/2016) in the Population Assessment of Tobacco and Health Study

INTRODUCTION

Understanding the population impact of e-cigarettes requires determining their effect on cigarette smoking cessation.

METHODS

Using the US Population Assessment of Tobacco and Health cohort, we examined smoking cessation among adult current cigarette smokers at Wave 1 with follow-up data at Waves 2 and 3 (n = 9724).

RESULTS

By Wave 3 (2015/2016), 17.3% of smokers had quit smoking. Smokers using e-cigarettes daily or who increased to daily use over the three waves were two to four times more likely to have quit in the short term (<1 year) and long term (1+ years) compared with never e-cigarette users (p < .001). E-cigarette use in the last quit attempt was associated with a higher likelihood of short-term (<1 year) quitting at Wave 3 (adjusted relative risk ratio: 1.33; 95% confidence interval: 1.04, 1.71) compared with smokers who did not use an e-cigarette in their last quit attempt. Noncurrent (no use in any wave) e-cigarette users and users who were unstable in use frequency were 33% and 47% less likely to quit in the short-term, respectively (p < .001). Flavored (vs nonflavored) and using a rechargeable (vs disposable) e-cigarette device was associated with an increased likelihood of both short- and long-term quitting.

CONCLUSION

Smoking cessation was more likely among frequent e-cigarette users, users of e-cigarettes in last quit attempt, and users of flavored and rechargeable devices. Less frequent, unstable, past, or never e-cigarette users were less likely to quit smoking. Monitoring the relationship between patterns of e-cigarette and cigarette use is complex but critical for gauging the potential of e-cigarettes as a harm reduction tool.

IMPLICATIONS

This study suggests that consistent and frequent e-cigarette use over time is associated with cigarette smoking cessation among adults in the United States. In addition, findings suggest that flavored e-cigarette use and use of rechargeable e-cigarette devices can facilitate smoking cessation. These results underscore the importance of carefully defining and characterizing e-cigarette exposure patterns, potential confounders, and use of e-cigarettes to quit smoking, as well as variations in length of the smoking cessation.

Estimating the Population Health Impact of Recently Introduced Modified Risk Tobacco Products: A Comparison of Different Approaches

Introduction

Various approaches have been used to estimate the population health impact of introducing a Modified Risk Tobacco Product (MRTP).

Aims and Methods

We aimed to compare and contrast aspects of models considering effects on mortality that were known to experts attending a meeting on models in 2018.

Results

Thirteen models are described, some focussing on e-cigarettes, others more general. Most models are cohort-based, comparing results with or without MRTP introduction. They typically start with a population with known smoking habits and then use transition probabilities either to update smoking habits in the “null scenario” or joint smoking and MRTP habits in an “alternative scenario”. The models vary in the tobacco groups and transition probabilities considered. Based on aspects of the tobacco history developed, the models compare mortality risks, and sometimes life-years lost and health costs, between scenarios. Estimating effects on population health depends on frequency of use of the MRTP and smoking, and the extent to which the products expose users to harmful constituents. Strengths and weaknesses of the approaches are summarized.

Conclusions

Despite methodological differences, most modellers have assumed the increase in risk of mortality from MRTP use, relative to that from cigarette smoking, to be very low and have concluded that MRTP introduction is likely to have a beneficial impact. Further model development, supplemented by preliminary results from well-designed epidemiological studies, should enable more precise prediction of the anticipated effects of MRTP introduction.

Implications

There is a need to estimate the population health impact of introducing modified risk nicotine-containing products for smokers unwilling or unable to quit. This paper reviews a variety of modeling methodologies proposed to do this, and discusses the implications of the different approaches. It should assist modelers in refining and improving their models, and help toward providing authorities with more reliable estimates.

Public health implications of vaping in the USA: the smoking and vaping simulation model

Background

Nicotine vaping products (NVPs) are increasingly popular worldwide. They may provide public health benefits if used as a substitute for smoking, but may create public health harms if used as a gateway to smoking or to discourage smoking cessation. This paper presents the Smoking and Vaping Model (SAVM), a user-friendly model which estimates the public health implications of NVPs in the USA.

Methods

SAVM adopts a cohort approach. We derive public health implications by comparing smoking- and NVP-attributable deaths and life-years lost under a No-NVP and an NVP Scenario. The No-NVP Scenario projects current, former, and never smoking rates via smoking initiation and cessation rates, with their respective mortality rates. The NVP Scenario allows for smoking- and NVP-specific mortality rates, switching from cigarette to NVP use, separate NVP and smoking initiation rates, and separate NVP and smoking cessation rates. After validating the model against recent US survey data, we present the base model with extensive sensitivity analyses.

Results

The SAVM projects that under current patterns of US NVP use and substitution, NVP use will translate into 1.8 million premature smoking- and vaping-attributable deaths avoided and 38.9 million life-years gained between 2013 and 2060. When the NVP relative risk is set to 5%, the results are sensitive to the level of switching and smoking cessation rates and to a lesser extent smoking initiation rates. When the NVP relative risk is raised to 40%, the public health gains in terms of averted deaths and LYL are reduced by 42% in the base case, and the results become much more sensitive to variations in the base case parameters.

Discussion

Policymakers, researchers, and other public health stakeholders can apply the SAVM to estimate the potential public health impact of NVPs in their country or region using their own data sources. In developing new simulation models involving NVPs, it will be important to conduct extensive sensitivity analysis and continually update and validate with new data.

Conclusion

The SAVM indicates the potential benefits of NVP use. However, given the uncertainty surrounding model parameters, extensive sensitivity analysis becomes particularly important.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12963-021-00250-7.

Rating the Valence of Media Content about Electronic Cigarettes Using Crowdsourcing: Testing Rater Instructions and Estimating the Optimal Number of Raters

Electronic cigarettes (e-cigarettes) are a controversial public health topic due to their increasing popularity among youth and the uncertainty about their risks and benefits. Researchers have started to assess the valence of media content about e-cigarette use, mostly using expert coding. The current study aims to offer a methodological framework and guideline when using crowdsourcing to rate the valence of e-cigarette media content. Specifically, we present (1) an experiment to determine rating instructions that would result in reliable valence ratings and (2) an analysis to identify the optimal number of raters needed to replicate these ratings. Specifically, we compared ratings produced by crowdsourced raters instructed to rate from several different perspectives (e.g., objective vs. subjective) and determined the instructions that led to reliable ratings. We then used bootstrapping methods and a set of criteria to identify the minimum number of raters needed to replicate these ratings. Results suggested that when rating e-cigarette valence, instructing raters to rate from their own subjective perspective produced reliable results, and nine raters were deemed the optimal number of raters. We expect these findings to inform future content analyses of e-cigarette valence. The study procedures can be applied to crowdsourced content analyses of other health-related media content to determine appropriate rating instructions and the number of raters.

A Magic Bullet? The Potential Impact of E-Cigarettes on the Toll of Cigarette Smoking

INTRODUCTION

We examine the proportion of US smoking-produced mortality that e-cigarettes might eliminate under assumptions regarding vaping's ability to increase smoking cessation, vaping's health risks, and the possibility that vaping will increase smoking among young people.

METHODS

We employ a dynamic population simulation model that tracks individuals from ages 0 to 110, differentiated by gender and smoking status. Using data from the US Census, the National Vital Statistics Reports, Cancer Prevention Study II, and the National Health Interview Survey, we estimate the number of smoking-related life-years lost (LYL) from 2018 to 2100 in a no-vaping scenario. We then compare results for model runs that assess the impact of vaping under a variety of assumptions.

RESULTS

The combination of assumptions produces 360 possible scenarios. 357 (99%) yield positive estimates of life-years saved (LYS) due to vaping by 2100, from 143 000 to 65 million. Most scenarios result in millions of individuals quitting smoking due to vaping. On average, vaping-induced quitters gain an extra 1.2-2.0 years of life compared to smokers who quit without vaping. The impact of vaping is greatest when it most helps smokers who otherwise have the greatest difficulty quitting smoking. While the numbers of LYS are generally large across all scenarios, they often represent a small fraction of the toll of smoking.

CONCLUSIONS

Vaping is highly likely to reduce smoking-produced mortality. Still, vaping is not "the" answer to the public health crisis created by smoking. Rather, it may well be a tool to add to the armamentarium of effective tobacco control measures.

IMPLICATIONS

E-cigarettes hold the potential to reduce cigarette smoking's enormous toll. By itself, however, tobacco harm reduction, as embodied in vaping, is no magic bullet. Going forward, tobacco control will require vigilant application of the evidence-based measures that have brought us so much success in combatting smoking. It will require, as well, the search for and adoption of novel means of attacking the remaining problem. Harm reduction can, and many would say should, be a part of the complex formula that will eventually bring about the demise of smoking.

Deposition of E-cigarette aerosol in human airways through passive vaping

Secondary exposure to e-cigarette aerosol (passive vaping) will soon become a pressing public health issue in the world. Yet, the current knowledge about respiratory depositions of e-cigarette aerosol through passive vaping in human airways is limited due to critical weaknesses of traditional experimental methods. To fill in this important knowledge gap, this study proposed a special approach involving an upgraded Mobile Aerosol Lung Deposition Apparatus (MALDA) that consists of a set of human airway replicas including a head airway, tracheobronchial airways down to the 11th lung generation, and a representative alveolar section. In addition to the comprehensive coverage of human airways, the MALDA is easily transportable for providing efficient estimations of aerosol respiratory deposition. In this study, the MALDA was first evaluated in the laboratory and then applied to estimate the respiratory deposition associated with passive vaping in an indoor real-life setting. The results showed that the respiratory deposition data aligned closely with the conventional respiratory deposition curves not only in the head-to-TB region but also in the alveolar region. The strengths of MALDA demonstrate great promise for a wide variety of applications in real-life settings that could provide crucial information for future public health and indoor air quality studies.