Comparing identity, attitudes, and indicators of effectiveness in people who smoke, vape or use heated tobacco products: A cross-sectional study

BACKGROUND

There is limited long-term and independent research on heated tobacco products (HTPs). We compared people who used HTPs with those who used nicotine vaping products (NVP) or cigarettes on smoker identity, indicators of effectiveness and, among NVP/HTP users, perceptions of these products.

METHODS

Adults exclusive cigarette smokers (N = 45) and ex-smokers with medium/long-term (>3months) NVP (N = 46) or HTP use (N = 45) were recruited in London, UK. Participants completed a questionnaire assessing socio-demographics, smoking characteristics, smoker identity, dependence, intention to stop and attitudes towards HTP/NVP.

RESULTS

In adjusted analysis, people who used cigarettes (Mean Difference (MD) = 1.4, 95%Confidence Intervals (CI) 0.7,2.0) and HTPs (MD = 0.8, 95%CI 0.1, 1.5) reported stronger smoker identities than those who used NVPs. Compared with smokers, HTP/NVP users had lower cravings for cigarettes (MD = 3.0, 95%CI 1.6, 4.3; MD = 3.1, 95%CI 1.9, 4.3, respectively), and higher intention to stop product use (MD = -0.8, 95%CI -1.7,-0.01; MD = -1.2, 95%CI -2.0, -0.3, respectively). People using HTPs or NVPs reported similar perceived product satisfaction (HTP:M = 3.4, 95%CI 2.8, 3.9; NVP:M = 3.0, 95%CI 2.5, 3.5), efficacy for smoking cessation (HTP:M = 4.5, 95%CI 4.2, 4.9; NVP:M = 4.6, 95%CI 4.3, 4.9) and safety (HTP:M = 2.1, 95%CI 2.0, 2.2; NVP:M = 2.0, 95%CI 1.8, 2.1). HTP users reported greater perceived addictiveness than NVPs (MD = 0.3, 95%CI 0.2, 0.6).

CONCLUSIONS

HTP and NVP users perceived products to be similarly acceptable and effective suggesting that HTPs, like NVPs, may support smoking cessation. However, since HTP use appears to maintain a stronger smoker identity and perceived addiction, this may suggest a more limited role of HTP for a permanent transition away from cigarettes.

Integrating a Systematic, Comprehensive E-Cigarette and Vaping Assessment Tool into the Electronic Health Record

BACKGROUND

Recently, the use of electronic cigarettes increased sharply, leading to increased e-cigarette, or Vaping Product Use-Associated Lung Injury (EVALI), and other acute pulmonary conditions. There is an urgent need for clinical information about e-cigarette users to identify factors that contribute to EVALI. We developed an e-cigarette/vaping assessment tool (EVAT) that was integrated into the Electronic Health Record (EHR) of a large state-wide medical system and initiated a system-wide dissemination and education to support its use.

METHODS

EVAT documented current vaping status, history, and e-cigarette content (nicotine, cannabinoids, and/or flavoring). Educational materials and presentations were developed via a comprehensive literature review. EVAT utilization in the EHR was assessed quarterly. Patients' demographic data and clinical site name were also collected.

RESULTS

The EVAT was built, validated, and integrated with the EHR in July 2020. Live and virtual seminars were conducted for prescribing providers and clinical staff. Asynchronous training was offered using podcasts, e-mails, and Epic tip sheets. Participants were informed about vaping harm and EVALI and instructed on the use of EVAT. As of December 31, 2022, EVAT was used 988,181 times, with 376,559 unique patients evaluated. Overall, 1,063 hospital units and affiliated ambulatory clinics used EVAT, including 64 Primary Care, 95 Pediatrics, and 874 Specialty sites.

CONCLUSIONS

EVAT was successfully implemented. Continued outreach efforts are needed to further increase its usage. Education materials should be enhanced to help providers to reach youth and vulnerable populations and connect patients to the tobacco treatment resources.

Differential impact of JUUL flavors on pulmonary immune modulation and oxidative stress responses in male and female mice

JUUL is a popular e-cigarette brand that manufactures e-liquids in a variety of flavors, such as mango and mint. Despite their popularity, the pulmonary effects of flavored JUUL e-liquids that are aerosolized and subsequently inhaled are not known. Therefore, the purpose of this study was to evaluate if acute exposure to JUUL e-cigarette aerosols in three popular flavors elicits an immunomodulatory or oxidative stress response in mice. We first developed a preclinical model that mimics human use patterns of e-cigarettes using 1 puff/min or 4 puffs/min exposure regimes. Based on cotinine levels, these exposures were representative of light/occasional and moderate JUUL users. We then exposed C57BL/6 mice to JUUL e-cigarette aerosols in mango, mint, and Virginia tobacco flavors containing 5% nicotine for 3 days, and assessed the inflammatory and oxidative stress response in the lungs and blood. In response to the 1 puff/min regime (light/occasional user), there were minimal changes in BAL cell composition or lung mRNA expression. However, at 4 puffs/min (moderate user), mint-flavored JUUL significantly increased lung neutrophils, while mango-flavored JUUL significantly increased Tnfα and Il13 mRNA in the lungs. Both the 1- and 4 puffs/min regimes significantly increased oxidative stress markers in the blood, indicating systemic effects. Thus, JUUL products are not inert; even short-term inhalation of flavored JUUL e-cigarette aerosols differentially causes immune modulation and oxidative stress responses.

The effect of emerging tobacco related products and their toxic constituents on thrombosis

Although conventional cigarette smoking is declining, emerging tobacco related products (ETRPs) are currently gaining ground, especially among the youth. These products include electronic cigarettes, waterpipes/hookah, cigars/cigarillo, smokeless tobacco, and heat-not-burn cigarettes. The observed increase in the use of ETRPs is multifactorial and complex but appears to be mainly driven by efforts from the major tobacco companies to reinvent themselves, and present more appealing and allegedly safe(r) tobacco products. However, it is becoming apparent that these products produce substantial amounts of toxic chemicals, many of which have been shown to exert negative health effects, including in the context of the cardiovascular system. Thus, there has been research efforts, albeit limited in general, to characterize the health impact of these products on occlusive/thrombotic cardiovascular diseases (CVD). In this review, we will discuss the potential impact of ETRPs on thrombosis-based CVD. Specifically, we will review how these products and the major chemicals they produce and/or emit can trigger key players in the process of thrombosis, namely inflammation, oxidative stress, platelets, coagulation, and the vascular endothelium, and the relationship between these effects.

Effects of α-pyrrolidino-phenone cathinone stimulants on locomotor behavior in female rats

The α-pyrrolidino-phenone cathinone stimulants first came to widespread attention because of bizarre behavior consequent to the use of α-pyrrolidinopentiophenone (α-PVP, "flakka") reported in popular press. As with other designer drugs, diversification of cathinones has been driven by desirable subjective effects, but also by attempts to stay ahead of legal controls of specific molecules. The α-pyrrolidinohexiophenone (α-PHP) and α-pyrrolidinopropiophenone (α-PPP) compounds have been relatively under-investigated relative to α-PVP and provide a key opportunity to also investigate structure-activity relationships, i.e., how the extension of the alpha carbon chain may affect potency or efficacy. Female rats were used to contrast the effects of α-PHP and α-PPP with those of α-PVP in altering wheel activity and effects on spontaneous locomotion, temperature and intracranial self-stimulation reward. The α-PPP, α-PHP and α-PVP compounds (5, 10 mg/kg, i.p.) suppressed wheel activity. Inhalation of α-PHP or α-PVP also suppressed wheel activity, but for an abbreviated duration compared with the injection route. Spontaneous activity was increased, and brain reward thresholds decreased, in a dose-dependent manner by all three compounds; only small decrements in body temperature were observed. These data show that all three of the α-pyrrolidino-phenone cathinones exhibit significant stimulant-like activity in female rats. Differences were minor and abuse liability is therefore likely to be equivalent for all three α-pyrrolidino-phenones.

A randomized controlled study in healthy participants to explore the exposure continuum when smokers switch to a tobacco heating product or an E-cigarette relative to cessation

Background

Cigarette smoking is associated with a number of diseases, such as cancer and cardiovascular diseases. Recently, there has been an increase in the use of electronic cigarettes (ECs) and tobacco-heating products (THPs) as an alternative to cigarettes, which may reduce the health burden associated with smoking. However, an exposure continuum when smokers switch to ECs or THPs compared to complete smoking cessation is not well established.

Methods

148 healthy smokers were randomized to either continue smoking cigarettes, switch to using the glo THP or a prototype EC, or completely quit any nicotine or tobacco product use for 5 days, after a 2-day baseline period. During this study breath and 24-h urine samples were collected for Biomarker of Exposure (BoE) analysis.

Results

After a 5-day switching period BoE levels showed a substantial significant decrease in levels from baseline in the groups using the glo THP, the prototype EC, and having quit all nicotine and tobacco use. On an exposure continuum, smokers who completely quit nicotine had the lowest levels of assessed BoEs, followed by those who switched to the EC and then those who switched to glo THP use. Participants who continued to smoke had the highest levels of BoEs.

Conclusions

THP or EC use over a 5-day period resulted in significant reductions in exposure to smoke toxicants, in some cases to levels similar to those for nicotine cessation. These results show that on an exposure continuum, nicotine cessation gives the greatest reduction in exposure to tobacco smoke toxicants, closely followed by the EC and the glo THP. These significant reductions in exposure to toxicants suggest that the glo THP and EC have the potential to be Reduced Risk Products.

Study Registration

ISRCTN80651909.

Comparison of the chemical composition of aerosols from heated tobacco products, electronic cigarettes and tobacco cigarettes and their toxic impacts on the human bronchial epithelial BEAS-2B cells

The electronic cigarettes (e-cigs) and more recently the heated tobacco products (HTP) provide alternatives for smokers as they are generally perceived to be less harmful than conventional cigarettes. However, it is crucial to compare the health risks of these different emergent devices, in order to determine which product should be preferred to substitute cigarette. The present study aimed to compare the composition of emissions from HTP, e-cigs and conventional cigarettes, regarding selected harmful or potentially harmful compounds, and their toxic impacts on the human bronchial epithelial BEAS-2B cells. The HTP emitted less polycyclic aromatic hydrocarbons and carbonyls than the conventional cigarette. However, amounts of these compounds in HTP aerosols were still higher than in e-cig vapours. Concordantly, HTP aerosol showed reduced cytotoxicity compared to cigarette smoke but higher than e-cig vapours. HTP and e-cig had the potential to increase oxidative stress and inflammatory response, in a manner similar to that of cigarette smoke, but after more intensive exposures. In addition, increasing e-cig power impacted levels of certain toxic compounds and related oxidative stress. This study provides important data necessary for risk assessment by demonstrating that HTP might be less harmful than tobacco cigarette but considerably more harmful than e-cig.

A vapor exposure method for delivering heroin alters nociception, body temperature and spontaneous activity in female and male rats

BACKGROUND

The ongoing crisis related to non-medical use of opioids makes it of continued importance to understand the risk factors for opioid addiction, the behavioral and neurobiological consequences of opioid exposure and to seek potential avenues for therapy. Pre-clinical rodent models have been critical to advancing understanding of opioid consequences for decades, but have been mostly limited to drug delivery by injection or by oral dosing. Inhalation, a significant route for many human users, has not been as well-established.

METHOD

We adapted an e-cigarette based exposure system, previously shown efficacious for delivery of other drugs to rats, to deliver heroin vapor. Effectsin vivo were assessed in male and female Sprague-Dawley rats using a warm-water assay for anti-nociception and an implanted radiotelemetry system for evaluating changes in body temperature and spontaneous activity rate.

RESULTS

Inhalation of vapor created by heroin 100 mg/mL in the propylene glycol (PG) vehicle significantly slowed tail-withdrawal from a 52 °C water bath, bi-phasically altered activity, and increased temperature in male and female rats. Inhalation of heroin 50 mg/mL for 15 min produced significant effects, as the lower bound on efficacy, whereas inhalation of heroin 100 mg/mL for 30 min produced robust effects across all endpoints and groups.

CONCLUSIONS

This work shows that e-cigarette devices deliver psychoactive doses of heroin to rats, using concentrations of ∼50-100 mg/mL and inhalation durations of 15-30 min. This technique may be useful to assess the health consequences of inhaled heroin and other opioid drugs.

Examining the Psychometric Properties of the CEAC (Comparing e-Cigarette and Cigarette) Questionnaire and Its Usefulness as a Predictor of e-Cigarette Use

Background: Electronic cigarette (e-cigarette) use continues to rise, while there is conflicting evidence about the health effects of its use. As such, research is needed to better determine risks factors for e-cigarette use. Accumulating evidence suggests that attitudes toward e-cigarette use could be a potential risk factor for e-cigarette use. Objectives: This study sought to examine the psychometric properties of the Comparing E-cigarette And Cigarette questionnaire (CEAC), and to replicate a structural model of the relationship between impulsive-related personality traits and e-cigarette use mediated by positive attitudes toward e-cigarettes. Methods: Participants were 525 adults (mean age = 33.42, SD = 11.27) who completed the CEAC and UPPS-P (trait impulsivity) questionnaires online. Results: Confirmatory factor analysis of the CEAC replicated the a priori factor structure of the questionnaire reasonably well (χ²(df = 32) =172.85, CFI = 0.94, TLI = 0.91, RMSEA = 0.09 (0.08-0.11, 90% Confidence Interval, SRMR = 0.06). Structural path analysis showed that deficits in conscientiousness was significantly negatively related to e-cigarette attitudes (β = -0.20, p = .01), while urgency (β = 0.19, p = .018) showed a significant positive relationship to e-cigarette attitudes. E-cigarette users showed significantly more positive attitudes toward e-cigarettes than nonusers (β = 0.59, p < .001). No significant direct effects were found between impulsivity-related traits and e-cigarette use. Conclusions: The present study suggests that impulsivity-related traits and attitudes toward e-cigarettes are likely to be important risk factors for e-cigarette use. Future prospective and experimental studies should test if the causal model described in this study predicts risk for e-cigarette use, and whether this model could therefore be used to guide strategies for reducing risk for e-cigarette use.

Development and validation of a method for quantification of two tobacco-specific nitrosamines in indoor air

A sensitive and accurate method for the quantification of 1'-Demethyl-1'-nitrosonicotine (NNN) and 4-(methylnitrosamino)-1-(3-Pyridyl)-1-butanone (NNK) in indoor air was developed and validated. To this aim, a novel approach for the collection of two tobacco-specific nitrosamines, using silica sorbent cartridges followed by simplified sample preparation and isotope dilution liquid chromatography/electrospray ionization tandem mass spectrometry, was applied. This procedure led to a substantial improvement in terms of sensitivity and sample throughput as compared with methods using conventional trapping. For the validation, a matrix-based approach using an accuracy profile procedure was selected. The evaluated matrices were background air samples, environmental aerosols of a heat-not-burn tobacco product (Tobacco Heating System [THS] 2.2, commercialized under the brand IQOS®), a rechargeable electronic cigarette (Solaris®), and the environmental tobacco smoke (ETS) of a conventional cigarette (Marlboro Gold®). The method showed excellent recoveries, sensitivity, and precision. The limits of detection of the method for NNN and NNK were 0.0108 ng/m3 and 0.0136 ng/m3, respectively. The calibration range of the instrument spanned 0.2-60 ng/mL. The calculated lower working range limit (LWRL) of the method for NNN was 0.126 ng/m3, and the LWRL for NNK was 0.195 ng/m3. The method was applied to evaluate surrogate environmental aerosols generated using smoking machines. This model is reliable but gives a large overestimation of the possible impact of THS 2.2 and e-cigarettes on indoor air, because the retention of NNN and NNK in the body of the consumers is not taken into account. As a consequence, the values reported do not reflect a real-life setting. The contents of the two target compounds in the surrogate environmental aerosols were 0.0830 ± 0.0153 ng/m3 of NNN and 0.0653 ± 0.0138 ng/m3 of NNK for THS 2.2, 0.0561 ± 0.0296 ng/m3 of NNN for e-cigarettes, and 0.816 ± 0.109 ng/m3 of NNN and 4.13 ± 1.04 ng/m3 NNK for cigarettes. These values correspond to 10% of the measured ETS concentration for NNN in environmental aerosols of THS 2.2 and 7% for those of e-cigarettes. For NNK, the value for the environmental aerosol of THS 2.2 was 2% of the ETS value.

Modulation of neural regulators of energy homeostasis, and of inflammation, in the pups of mice exposed to e-cigarettes

BACKGROUND

Maternal smoking can lead to perturbations in central metabolic regulators such as neuropeptide Y (NPY) and pro-opiomelanocortin (POMC) signalling components in offspring. With the growing interest in e-cigarettes as a tobacco replacement, this short report assessed central metabolic regulation in offspring of mouse dams exposed to e-cigarettes. We examined the impact of continuous use of e-cigarettes, and e-cigarette replacement of tobacco cigarettes during pregnancy. Supplementation of an antioxidant l-carnitine was also co-used with tobacco cigarette in the mother to determine whether the impact of maternal tobacco smoking was oxidative stress driven.

METHODS

Balb/c mice were exposed to either nicotine-containing (E-cig18) or nicotine-free (E-cig0) e-cigarette aerosols or tobacco smoke (SE) prior to mating and until their pups were weaned. After mating, two SE sub-groups were changed to E-cig18 exposure (Replacement), or supplementation l-carnitine while SE was continued. Male offspring were studied at weaning age.

RESULTS

The offspring of E-cig0 dams were the heaviest with the most body fat. Replacing SE with E-cig18 during pregnancy resulted in offspring with significantly less body fat. E-cig0 offspring had significantly increased mRNA expression of brain NPY and iNOS. Maternal SE upregulated mRNA expression of NPY, NPY Y1 receptor, POMC downstream components, and iNOS expression, which were normalised in Replacement offspring, but only partially normalised with maternal L-carnitine supplementation during gestation and lactation.

CONCLUSIONS

Maternal exposure to either tobacco and nicotine-free e-cigarettes lead to disturbances in the level of central homeostatic control markers in offspring, suggesting that maternal exposure to e-cigarettes is not without risks.

Documentation of e-cigarette use and associations with smoking from 2012 to 2015 in an integrated healthcare delivery system

It is unclear whether use of electronic nicotine delivery systems (ENDS) precedes cigarette smoking initiation, relapse, and/or quitting. Healthcare systems with electronic health records (EHRs) provide unique data to examine ENDS use and changes in smoking. We examined the incidence of ENDS use (2012-2015) based on clinician documentation and tested whether EHR documented ENDS use is associated with twelve-month changes in patient smoking status using a matched retrospective cohort design. The sample was Kaiser Permanente Northern California (KPNC) patients aged ≥12 with documented ENDS use (N = 7926); 57% were current smokers, 35% former smokers, and 8% never-smokers. ENDS documentation incidence peaked in 2014 for current and former smokers and in 2015 for never-smokers. We matched patients with documented ENDS use to KPNC patients without documented ENDS use (N = 7926) on age, sex, race/ethnicity, and smoking status. Documented ENDS use predicted the likelihood of smoking in the following year. Among current smokers, ENDS use was associated with greater odds of quitting smoking (OR = 1.17, 95%CI = 1.05-1.31). Among former smokers, ENDS use was associated with greater odds of smoking relapse (OR = 1.53, 95%CI = 1.22-1.92). Among never-smokers, ENDS use was associated with greater odds of initiating smoking (OR = 7.41, 95%CI = 3.14-17.5). The overall number of current smokers at 12 months was slightly higher among patients with (N = 3931) versus without (N = 3850) documented ENDS use. Results support both potential harm reduction of ENDS use (quitting combustibles among current smokers) and potential for harm (relapse to combustibles among former smokers, initiation for never-smokers).

Nicotine delivery efficiency of first- and second-generation e-cigarettes and its impact on relief of craving during the acute phase of use

Knowledge about the change in blood nicotine concentrations during the first five minutes (acute phase) of e-cigarette vaping is important to determine whether the used product has a dependence potential or may be an efficient nicotine replacement product. To address this issue, we monitored blood nicotine levels during the acute phase in volunteers using disposable cigalikes (CLs) and a tank model (TM) and compared them with blood nicotine levels in subjects using a tobacco cigarette (TC). In parallel, heart rate changes were continually measured and withdrawal symptoms and craving were assessed with the Questionnaire on Smoking Urges before and immediately after the vaping/smoking sessions. Additionally, at the end of each session negative health effects were rated on a visual analog scale. After five minutes of e-cigarette or TC use, the mean nicotine plasma concentrations were as follows: CLs, 5.5ng/ml; TM, 9.3ng/ml; TC, 17.1ng/ml. Nicotine levels increased significantly faster in the first 4min of consuming a TC than with the CLs and the TM. The highest rate of increase in nicotine concentration was found with the TC (6.8ng/ml) and TM (2.3ng/ml) between the 1st and 2nd minute, whereas the CLs showed comparatively small changes in the amount delivered over the five minutes. Withdrawal and craving for smoking decreased with the TM by the same amount as with the TC, even though less nicotine was delivered to the blood and considerably fewer side effects occurred. The heart rate of TM users was also markedly lower than that of the TC users. Unlike CLs, TM e-cigarettes represent an effective source of nicotine and might be used as an alternative nicotine replacement product to aid smoking cessation. However, nicotine plasma levels observed in TM users after short-time vaping have also the potential to produce and sustain nicotine addiction.

Distinctive role of opinion leaders in the social networks of school adolescents: an investigation of e-cigarette use

OBJECTIVES

This study examines a diverse set of social motives (e.g. peer support, peer pressure, social loneliness) for e-cigarette use, through the mediating effects of opinion leadership, among both male and female adolescents.

STUDY DESIGN

Prospective cohort study.

METHODS

The data were obtained from a survey conducted among 666 adolescents across 14 school classes, namely, students at three urban schools, public and private, in Lille, France. The proposed integrative model includes social motives, opinion leadership and e-cigarette use in a trilateral relationship; gender is proposed and tested as a potential moderator in a structural equation model.

RESULTS

More positive peer support is negatively associated with opinion leadership and e-cigarette use. Both loneliness and susceptibility to peer influence are positively related to opinion leadership and e-cigarette use. Moreover, social support from peers and opinion leadership shape e-cigarette use differently across genders.

CONCLUSIONS

Policy makers should account for the various (positive and negative) roles of peers and consider the gender of their audience when designing anti-e-cigarette policies.

Effects of sweet flavorings and nicotine on the appeal and sensory properties of e-cigarettes among young adult vapers: Application of a novel methodology

INTRODUCTION

Product characteristics that impact e-cigarette appeal by altering the sensory experience of vaping need to be identified to formulate evidence-based regulatory policies. While products that contain sweet flavorings and produce a "throat hit" (i.e., desirable airway irritation putatively caused by nicotine) are anecdotally cited as desirable reasons for vaping among young adults, experimental evidence of their impact on user appeal is lacking. This experiment applied a novel laboratory protocol to assess whether: (1) sweet flavorings and nicotine affect e-cigarette appeal; (2) sweet flavorings increase perceived sweetness; (3) nicotine increases throat hit; and (4) perceived sweetness and throat hit are associated with appeal.

METHODS

Young adult vapers (N=20; age 19-34) self-administered 20 standardized doses of aerosolized e-cigarette solutions varied according to a 3 flavor (sweet [e.g., cotton candy] vs. non-sweet [e.g., tobacco-flavored] vs. flavorless)×2 nicotine (6mg/mL nicotine vs. 0mg/mL [placebo]) double-blind, cross-over design. Participants rated appeal (liking, willingness to use again and perceived monetary value), perceived sweetness and throat hit strength after each administration.

RESULTS

Sweet-flavored (vs. non-sweet and flavorless) solutions produced greater appeal and perceived sweetness ratings. Nicotine produced greater throat hit ratings than placebo, but did not significantly increase appeal nor interact with flavor effects on appeal. Controlling for flavor and nicotine, perceived sweetness was positively associated with appeal ratings; throat hit was not positively associated with appeal.

CONCLUSIONS

Further identification of compounds in e-cigarette solutions that enhance sensory perceptions of sweetness, appeal, and utilization of e-cigarettes are warranted to inform evidence-based regulatory policies.

Perceptions of e-cigarettes: a comparison of adult smokers and non-smokers in a Mechanical Turk sample

BACKGROUND

Given plans to extend its regulatory authority to e-cigarettes, the Food and Drug Administration (FDA) urgently needs to understand how e-cigarettes are perceived by the public.

OBJECTIVES

To examine how smoking status impacts adult perceptions and expectations of e-cigarettes.

METHODS

We used Mechanical Turk (MTurk), a "crowdsourcing" platform, to rapidly survey a large (n = 796; female = 381; male = 415), diverse sample of adult ever (44%) and never smokers (56%), including ever (28%) and never (72%) users of e-cigarettes.

RESULTS

Smokers and non-smokers learned about e-cigarettes primarily through the internet and conversations with others. Ever smokers were more likely than never smokers, and female current smokers were more likely than female former smokers, to have learned about e-cigarettes from point of sale advertising (p's < 0.05) and to believe that e-cigarettes help smokers quit (ps < 0.05). Among never users of e-cigarettes, current smokers were more likely than never smokers and former smokers to report that they would try e-cigarettes in the future (ps < 0.01). Current smokers' top reason for wanting to try e-cigarettes was to quit or reduce smoking (56%), while never and former smokers listed curiosity. In contrast, female current smokers' top reason for not trying e-cigarettes was health and safety concerns (44%) while males were deterred by expense (44%).

CONCLUSIONS

Adult smokers and non-smokers have different perceptions and expectations of e-cigarettes. Public health messages regarding e-cigarettes may need to be tailored separately for persons with and without a history of using conventional cigarettes. Tailoring messages by gender within smoker groups may also improve their impact.

A framework for in vitro systems toxicology assessment of e-liquids

Various electronic nicotine delivery systems (ENDS), of which electronic cigarettes (e-cigs) are the most recognized prototype, have been quickly gaining ground on conventional cigarettes because they are perceived as less harmful. Research assessing the potential effects of ENDS exposure in humans is currently limited and inconclusive. New products are emerging with numerous variations in designs and performance parameters within and across brands. Acknowledging these challenges, we present here a proposed framework for an in vitro systems toxicology assessment of e-liquids and their aerosols, intended to complement the battery of assays for standard toxicity assessments. The proposed framework utilizes high-throughput toxicity assessments of e-liquids and their aerosols, in which the device-to-device variability is minimized, and a systems-level investigation of the cellular mechanisms of toxicity is an integral part. An analytical chemistry investigation is also included as a part of the framework to provide accurate and reliable chemistry data solidifying the toxicological assessment. In its simplest form, the framework comprises of three main layers: (1) high-throughput toxicity screening of e-liquids using primary human cell culture systems; (2) toxicity-related mechanistic assessment of selected e-liquids, and (3) toxicity-related mechanistic assessment of their aerosols using organotypic air-liquid interface airway culture systems. A systems toxicology assessment approach is leveraged to enable in-depth analyses of the toxicity-related cellular mechanisms of e-liquids and their aerosols. We present example use cases to demonstrate the suitability of the framework for a robust in vitro assessment of e-liquids and their aerosols.

Ideology versus evidence: Investigating the claim that the literature on e-cigarettes is undermined by material conflict of interest

A review of the health effects of e-cigarettes (EC) by Pisinger and Dossing concluded that any reassuring the evidence on the contents of e-cigarettes cannot be trusted because 'A substantial number of studies were funded or otherwise supported by manufacturers of ECs' and the relevant literature is influenced by 'severe conflicts of interest' (A). The review also asserts that 'Conflict of interest seems to influence the conclusions of these papers' (BC). These claims have been embraced and magnified by EC opponents. The Pisinger and Dossing review included 76 studies and considered 26 (34%) to be 'funded or otherwise supported' by the industry. As the review identifies the 'conflicted' studies, such a claim can be checked. In summary, only 10 (13%) of articles covered by the review were sponsored by the industry and only 5 are published studies. Claim 'A' is misleading. Regarding claim 'B', it appears to have been conceived independent of any empirical support. Recently, anti-EC activists and media started to use conflict of interest accusations to disparage the validity of empirical evidence showing that vaping is much safer than smoking. Evidence needs to be considered on its merits rather than from the perspective of preconceived ideological positions.

Country-level correlates of e-cigarette use in the European Union

OBJECTIVES

The aim of this study was to assess the relationship between the prevalence of e-cigarette use and country-level factors across 28 European countries.

METHODS

The study objectives were addressed in an ecological design in which both exposures and outcomes were measured at the country level. Data from the Eurobarometer Report, the Eurostat database and the WHO observatory were analyzed. Bivariate and multivariate analyses were performed considering the rates of current and ever smokers of e-cigarettes as dependent variables, and socio-economic factors, health status and policies against tobacco as independent variables.

RESULTS

Both the rate of current smokers and ever smokers of e-cigarette were positively associated to the offer of help to quit tobacco use (P < 0.01; P = 0.04) and to the raise of taxes on tobacco (P = 0.01; P = 0.01). The warn on dangers of tobacco negatively correlated with the rate of e-cigarette current smokers. The rate of current e-cigarette smokers correlated with the rate of current smokers and with national Gross Domestic Product, while the rate of ever e-cigarette smokers did not correlate with any socio-economic factor.

CONCLUSIONS

Our analysis suggests that both policy and non-policy factors are associated with the geographical variability seen in the prevalence of e-cigarette use. Policies against the consumption of conventional tobacco products may lead to an increase of e-cigarette smokers.

Correlation of volatile carbonyl yields emitted by e-cigarettes with the temperature of the heating coil and the perceived sensorial quality of the generated vapours

E-liquids generally contain four main components: nicotine, flavours, water and carrier liquids. The carrier liquid dissolves flavours and nicotine and vaporises at a certain temperature on the atomizer of the e-cigarette. Propylene glycol and glycerol, the principal carriers used in e-liquids, undergo decomposition in contact with the atomizer heating-coil forming volatile carbonyls. Some of these, such as formaldehyde, acetaldehyde and acrolein, are of concern due to their adverse impact on human health when inhaled at sufficient concentrations. The aim of this study was to correlate the yield of volatile carbonyls emitted by e-cigarettes with the temperature of the heating coil. For this purpose, a popular commercial e-liquid was machine-vaped on a third generation e-cigarette which allowed the variation of the output wattage (5-25W) and therefore the heat generated on the atomizer heating-coil. The temperature of the heating-coil was determined by infrared thermography and the vapour generated at each temperature underwent subjective sensorial quality evaluation by an experienced vaper. A steep increase in the generated carbonyls was observed when applying a battery-output of at least 15W corresponding to 200-250°C on the heating coil. However, when considering concentrations in each inhaled puff, the short-term indoor air guideline value for formaldehyde was already exceeded at the lowest wattage of 5W, which is the wattage applied in most 2nd generation e-cigarettes. Concentrations of acetaldehyde in each puff were several times below the short-term irritation threshold value for humans. Acrolein was only detected from 20W upwards. The negative sensorial quality evaluation by the volunteering vaper of the vapour generated at 20W demonstrated the unlikelihood that such a wattage would be realistically set by a vaper. This study highlights the importance to develop standardised testing methods for the assessment of carbonyl-emissions and emissions of other potentially harmful compounds from e-cigarettes. The wide variety and variability of products available on the market make the development of such methods and the associated standardised testing conditions particularly demanding.

Use of electronic cigarettes (e-cigarettes) impairs indoor air quality and increases FeNO levels of e-cigarette consumers

Despite the recent popularity of e-cigarettes, to date only limited data is available on their safety for both users and secondhand smokers. The present study reports a comprehensive inner and outer exposure assessment of e-cigarette emissions in terms of particulate matter (PM), particle number concentrations (PNC), volatile organic compounds (VOC), polycyclic aromatic hydrocarbons (PAH), carbonyls, and metals. In six vaping sessions nine volunteers consumed e-cigarettes with and without nicotine in a thoroughly ventilated room for two hours. We analyzed the levels of e-cigarette pollutants in indoor air and monitored effects on FeNO release and urinary metabolite profile of the subjects. For comparison, the components of the e-cigarette solutions (liquids) were additionally analyzed. During the vaping sessions substantial amounts of 1,2-propanediol, glycerine and nicotine were found in the gas-phase, as well as high concentrations of PM2.5 (mean 197 μg/m(3)). The concentration of putative carcinogenic PAH in indoor air increased by 20% to 147 ng/m(3), and aluminum showed a 2.4-fold increase. PNC ranged from 48,620 to 88,386 particles/cm(3) (median), with peaks at diameters 24-36 nm. FeNO increased in 7 of 9 individuals. The nicotine content of the liquids varied and was 1.2-fold higher than claimed by the manufacturer. Our data confirm that e-cigarettes are not emission-free and their pollutants could be of health concern for users and secondhand smokers. In particular, ultrafine particles formed from supersaturated 1,2-propanediol vapor can be deposited in the lung, and aerosolized nicotine seems capable of increasing the release of the inflammatory signaling molecule NO upon inhalation. In view of consumer safety, e-cigarettes and nicotine liquids should be officially regulated and labeled with appropriate warnings of potential health effects, particularly of toxicity risk in children.