Flavourings significantly affect inhalation toxicity of aerosol generated from electronic nicotine delivery systems (ENDS).
ABSTRACT: E-cigarettes or electronic nicotine delivery systems (ENDS) are designed to deliver nicotine-containing aerosol via inhalation. Little is known about the health effects of flavoured ENDS aerosol when inhaled.Aerosol from ENDS was generated using a smoking machine. Various types of ENDS devices or a tank system prefilled with liquids of different flavours, nicotine carrier, variable nicotine concentrations and with modified battery output voltage were tested. A convenience sample of commercial fluids with flavour names of tobacco, piña colada, menthol, coffee and strawberry were used. Flavouring chemicals were identified using gas chromatography/mass spectrometry. H292 human bronchial epithelial cells were directly exposed to 55 puffs of freshly generated ENDS aerosol, tobacco smoke or air (controls) using an air-liquid interface system and the Health Canada intense smoking protocol. The following in vitro toxicological effects were assessed: (1) cell viability, (2) metabolic activity and (3) release of inflammatory mediators (cytokines).Exposure to ENDS aerosol resulted in decreased metabolic activity and cell viability and increased release of interleukin (IL)-1?, IL-6, IL-10, CXCL1, CXCL2 and CXCL10 compared to air controls. Cell viability and metabolic activity were more adversely affected by conventional cigarettes than most tested ENDS products. Product type, battery output voltage and flavours significantly affected toxicity of ENDS aerosol, with a strawberry-flavoured product being the most cytotoxic.Our data suggest that characteristics of ENDS products, including flavours, may induce inhalation toxicity. Therefore, ENDS users should use the products with caution until more comprehensive studies are performed.
Project description:INTRODUCTION:In the USA, Food and Drug Administration regulations prohibit the sale of flavoured cigarettes, with menthol being the exception. However, the manufacture, advertisement and sale of flavoured cigar products are permitted. Such flavourings influence positive perceptions of tobacco products and are linked to increased use. Flavourings may mask the taste of tobacco and enhance smoke inhalation, influencing toxicant exposure and abuse liability among novice tobacco users. Using clinical laboratory methods, this study investigates how flavour availability affects measures of abuse liability in young adult cigarette smokers. The specific aims are to evaluate the effect of cigar flavours on nicotine exposure, and behavioural and subjective measures of abuse liability. METHODS AND ANALYSES:Participants (projected n=25) are healthy smokers of five or more cigarettes per day over the past 3?months, 18-25 years old, naive to cigar use (lifetime use of 50 or fewer cigar products and no more than 10 cigars smoked in the past 30 days) and without a desire to quit cigarette smoking in the next 30 days. Participants complete five laboratory sessions in a Latin square design with either their own brand cigarette or a session-specific Black & Mild cigar differing in flavour (apple, cream, original and wine). Participants are single-blinded to cigar flavours. Each session consists of two 10-puff smoking bouts (30?s interpuff interval) separated by 1?hour. Primary outcomes include saliva nicotine concentration, behavioural economic task performance and response to various questionnaire items assessing subjective effects predictive of abuse liability. Differences in outcomes across own brand cigarette and flavoured cigar conditions will be tested using linear mixed models. ETHICS AND DISSEMINATION:The Virginia Commonwealth University Institutional Review Board approved the study (VCU IRB: HM20007848). Dissemination channels for study findings include scientific journals, scientific meetings, and policy briefs. TRIAL REGISTRATION NUMBER:NCT02937051.
Project description:BACKGROUD:JUUL, an electronic nicotine delivery system (ENDS), which first appeared on the US market in 2015, controled more than 75% of the US ENDS sales in 2018. JUUL-type devices are currently the most commonly used form of ENDS among youth in the US. In contrast to free-base nicotine contained in cigarettes and other ENDS, JUUL contains high levels of nicotine salt (35 or 59 mg/mL), whose cellular and molecular effects on lung cells are largely unknown. In the present study, we evaluated the in vitro toxicity of JUUL crème brûlée-flavored aerosols on 2 types of human bronchial epithelial cell lines (BEAS-2B, H292) and a murine macrophage cell line (RAW 264.7). METHODS:Human lung epithelial cells and murine macrophages were exposed to JUUL crème brûlée-flavored aerosols at the air-liquid interface (ALI) for 1-h followed by a 24-h recovery period. Membrane integrity, cytotoxicity, extracellular release of nitrogen species and reactive oxygen species, cellular morphology and gene expression were assessed. RESULTS:Crème brûlée-flavored aerosol contained elevated concentrations of benzoic acid (86.9 ?g/puff), a well-established respiratory irritant. In BEAS-2B cells, crème brûlée-flavored aerosol decreased cell viability (??50%) and increased nitric oxide (NO) production (??30%), as well as iNOS gene expression. Crème brûlée-flavored aerosol did not affect the viability of either H292 cells or RAW macrophages, but increased the production of reactive oxygen species (ROS) by ??20% in both cell types. While crème brûlée-flavored aerosol did not alter NO levels in H292 cells, RAW macrophages exposed to crème brûlée-flavored aerosol displayed decreased NO (??50%) and down-regulation of the iNOS gene, possibly due to increased ROS. Additionally, crème brûlée-flavored aerosol dysregulated the expression of several genes related to biotransformation, inflammation and airway remodeling, including CYP1A1, IL-6, and MMP12 in all 3 cell lines. CONCLUSION:Our results indicate that crème brûlée-flavored aerosol causes cell-specific toxicity to lung cells. This study contributes to providing scientific evidence towards regulation of nicotine salt-based products.
Project description:INTRODUCTION:IQOS is an emerging heated tobacco product marketed by Philip Morris International (PMI). Because the tobacco in IQOS is electrically heated and not combusted, PMI claims that it generates significantly lower toxicant levels than combustible cigarettes. To date, a few independent studies have addressed IQOS toxicant emissions, and none have reported reactive oxygen species (ROS), and the form of the nicotine emitted by the device. METHODS:In this study, IQOS aerosol was generated using a custom-made puffing machine. Two puffing regimens were used: Health Canada Intense and ISO. ROS, carbonyl compounds (CCs), and total nicotine and its partitioning between free-base and protonated forms were quantified in the IQOS aerosol by fluorescence, high-performance liquid chromatography, and gas chromatography, respectively. The same toxicants were also quantified in combustible cigarette aerosols for comparison. In addition, propylene glycol and vegetable glycerin were also measured in the IQOS tobacco and aerosol. RESULTS:IQOS and combustible cigarettes were found to emit similar quantities of total and free-base nicotine. IQOS total ROS (6.26 ± 2.72 nmol H2O2/session) and CC emissions (472 ± 19 µg/session) were significant, but 85% and 77% lower than levels emitted by combustible cigarettes. CONCLUSIONS:IQOS emits harmful constituents that are linked to cancer, pulmonary disease, and addiction in cigarette smokers. For a given nicotine intake, inhalation exposure to ROS and CCs from IQOS is likely to be significantly less than that for combustible cigarettes. IMPLICATIONS:IQOS is PMI's new heated tobacco product. PMI claims that because IQOS heats and does not burn tobacco it generates low toxicant yields. We found that one IQOS stick can emit similar free-base and total nicotine yields as a combustible cigarette. A pack-a-day equivalent user of IQOS may experience significant inhalation exposure of ROS and CCs compared to background air. However, substituting IQOS for combustible cigarettes will likely result in far lower ROS and carbonyl inhalation exposure for a given daily nicotine intake.
Project description:OBJECTIVES:Given the exponential increase in the use of e-cigarettes among younger age groups and in the growth in research on e-cigarette flavours, we conducted a systematic review examining the impact of non-menthol flavoured e-cigarettes on e-cigarette perceptions and use among youth and adults. DESIGN:PubMed, Embase, PyscINFO and CINAHL were systematically searched for studies published and indexed through March 2018. ELIGIBILITY CRITERIA:Quantitative observational and experimental studies that assessed the effect of non-menthol flavours in e-cigarettes on perceptions and use behaviours were included. Specific outcome measures assessed are appeal, reasons for use, risk perceptions, susceptibility, intention to try, initiation, preference, current use, quit intentions and cessation. DATA EXTRACTION AND SYNTHESIS:Three authors independently extracted data related to the impact of flavours in tobacco products. Data from a previous review were then combined with those from the updated review for final analysis. Results were then grouped and analysed by outcome measure. RESULTS:The review included 51 articles for synthesis, including 17 published up to 2016 and an additional 34 published between 2016 and 2018. Results indicate that non-menthol flavours in e-cigarettes decrease harm perceptions (five studies) and increase willingness to try and initiation of e-cigarettes (six studies). Among adults, e-cigarette flavours increase product appeal (seven studies) and are a primary reason many adults use the product (five studies). The role of flavoured e-cigarettes on smoking cessation remains unclear (six studies). CONCLUSION:This review provides summary data on the role of non-menthol flavours in e-cigarette perceptions and use. Consistent evidence shows that flavours attract both youth and adults to use e-cigarettes. Given the clear findings that such flavours increase product appeal, willingness to try and initiation among youth, banning non-menthol flavours in e-cigarettes may reduce youth e-cigarette use. Longitudinal research is needed to examine any role flavours may play in quit behaviours among adults.
Project description:While flavoured cigarettes were prohibited in the USA in 2009, flavoured little cigars and cigarillos (LCCs) remain on the market. We describe the evolving strategies used by tobacco companies to encourage uptake of flavoured LCCs and industry research findings on consumer perceptions of flavoured LCC products.Analysis of internal tobacco industry documents was triangulated with data from tobacco advertisement archives, national newspapers, trade press and the internet.Flavoured LCC products were associated with young and inexperienced tobacco users, women and African-Americans. Internal industry studies confirmed that menthol and candy-like flavours (eg, vanilla and cherry) increased LCC appeal to starters by masking the heavy cigar taste, reducing throat irritation and making LCC smoke easier to inhale. To appeal to new users, manufacturers also reduced the size of cigars to make them more cigarette-like, introduced filters and flavoured filter tips, emphasised mildness and ease of draw in advertising, and featured actors using little cigars in television commercials. RJ Reynolds tried to capitalise on the popularity of menthol cigarettes among African-Americans and marketed a menthol little cigar to African-Americans.Tobacco companies engaged in a calculated effort to blur the line between LCCs to increase the appeal to cigarette smokers, and the use of flavours facilitated these efforts. Bans on flavoured cigarettes should be expanded to include flavoured LCCs, and tobacco use prevention initiatives should include LCCs.
Project description:Introduction: Although electronic cigarettes (e-cigarettes) were originally developed to deliver aerosolized nicotine to lungs, recent data have shown that consumers also use them for inhalation of other drugs, including cannabidiol (CBD). The aim of this study was to test the acute inhalation toxicity of flavored CBD-containing aerosols emitted from e-cigarettes. Methods: Bronchial epithelial cells (H292) cells were exposed to aerosol generated from e-cigarettes refilled either with (1) propylene glycol solvent only (PG, control), (2) commercially purchased unflavored solution with CBD, or (3) commercially purchased solutions with and without CBD and with different flavors. The in vitro toxicological effects were assessed using the following methods: (1) trypan blue exclusion assay (cell viability), (2) neutral red uptake assay (metabolic activity), and (3) ELISA (concentrations of inflammatory mediators). Results: Most flavored products with or without CBD were cytotoxic as compared to the air control. Overall, aerosols with CBD were more cytotoxic than aerosols without CBD irrelevant of the flavoring used in the product. Although, unflavored aerosols containing CBD in PG were significantly more cytotoxic than aerosols containing only PG, not all flavored products containing CBD were significantly more toxic than the same flavored products without CBD. Most CBD containing products significantly increase the concentration of cytokines released as compared to the same flavored products without CBD. Conclusion: Different flavors show different cytotoxic effects in CBD-containing e-cigarettes. Aerosols emitted from CBD containing e-cigarettes were more cytotoxic than those emitted from CBD-free e-cigarettes.
Project description:Non-menthol characterising flavours (eg, fruit, candy) are banned in cigarettes, yet are still permitted in non-cigarette tobacco (NCT) products. This study examined associations between first use and current use of flavoured tobacco products, and current flavoured tobacco use and quit behaviours.A nationally representative, telephone-based survey completed in 2012 by 1443 US adult tobacco users asked about use of 9 tobacco products: cigarettes, e-cigarettes, cigars, cigarillos, little filtered cigars, pipes, hookah, smokeless tobacco and snus. Ever users reported first use of flavoured products, while current users also reported current flavoured product use. Current users reported quit attempts made in the past year. Data were weighted to reflect the US adult tobacco user population. Logistic regression models were used to examine associations between first/current flavour use and quit behaviours.Over 70% of respondents reported first use of a flavoured tobacco product, while 54% reported current use of at least one flavoured product. Odds of current flavoured product use were greater among those who reported first use of a flavoured product (OR 14.82, 95% CI 9.96 to 22.06). First use of a flavoured product was associated with being a current tobacco user (OR 1.55, 95% CI 1.08 to 2.22). Compared to single product users, polytobacco users exhibited greater odds of reporting current use of flavoured products (OR 2.09, 95% CI 1.47 to 2.97). Forty-four percent of current tobacco users reported a past-year quit attempt. Adjusted analyses among current NCT users of at least one flavoured tobacco product showed reduced odds of reporting a quit attempt.First use of a flavoured tobacco product was associated with current flavoured tobacco use and polytobacco use. Users of only flavoured NCT products exhibited reduced odds of reporting a quit attempt. Findings from this study reinforce the importance of flavoured product availability in the USA, which may have significant implications for efforts to reduce tobacco initiation and use at a population level. The relationship between characterising flavours and quit behaviours merits further exploration in longitudinal, population-based samples.
Project description:INTRODUCTION:Limited data exist on flavoured non-cigarette tobacco product (NCTP) use among US adults. METHODS:Data from the 2013 to 2014 National Adult Tobacco Survey (N=75?233), a landline and cellular telephone survey of US adults aged ?18, were assessed to estimate past 30-day NCTP use, flavoured NCTP use and flavour types using bivariate analyses. RESULTS:During 2013-2014, 14.4% of US adults were past 30-day NCTP users. Nationally, an estimated 10.2 million e-cigarette users (68.2%), 6.1 million hookah users (82.3%), 4.1 million cigar smokers (36.2%) and 4.0 million smokeless tobacco users (50.6%) used flavoured products in the past 30?days. The most prevalent flavours reported were menthol/mint (76.9%) for smokeless tobacco; fruit (74.0%) for hookah; fruit (52.4%), candy/chocolate/other sweet flavours (22.0%) and alcohol (14.5%) for cigars/cigarillos/filtered little cigars; fruit (44.9%), menthol/mint (43.9%) and candy/chocolate/other sweet flavours (25.7%) for e-cigarettes and fruit (56.6%), candy/chocolate/other sweet flavours (26.5%) and menthol/mint (24.8%) for pipes. Except for hookah and pipes, past 30-day flavoured product use was highest among 18-24-year olds. By cigarette smoking, never smoking e-cigarette users (84.8%) were more likely to report flavoured e-cigarette use, followed by recent former smokers (78.1%), long-term former smokers (70.4%) and current smokers (63.2%). CONCLUSIONS:Flavoured NCTP use is prominent among US adult tobacco users, particularly among e-cigarette, hookah and cigar users. Flavoured product use, especially fruit and sweet-flavoured products, was higher among younger adults. It is important for tobacco prevention and control strategies to address all forms of tobacco use, including flavoured tobacco products.
Project description:RATIONALE:Electronic nicotine delivery systems (ENDS or e-cigarettes) share salient features of combustible smoking, such as inhalation and exhalation behaviors, and evidence indicates that first- and second-generation ENDS generalize as smoking cues. The present study examined whether newer, tank-based third-generation ENDS ("mods") also evoke smoking urges, and whether enhancing the visibility of exhaled aerosol clouds-by increasing the e-liquid vegetable glycerin (VG) content-strengthens the cue salience of ENDS. OBJECTIVES:The objective was to assess the role of exhaled aerosol clouds on ENDS cue potency using a standardized laboratory paradigm designed to mimic real-world exposures. METHODS:Using a mixed design, young adult smokers (n?=?50; mean age 26.5 years; ??5 cigarettes/day) observed a study confederate drinking bottled water (control cue) and vaping an ENDS mod containing e-liquid with either high (73%) or low (0%) VG. Participants completed the Brief Questionnaire on Smoking Urges (BQSU) and visual analog scales (VAS) assessing cigarette and e-cigarette desire pre- and post-cue exposure. RESULTS:Increasing the e-liquid content of VG enhanced the size and visibility of the exhaled aerosol clouds and evoked a greater increase in smoking desire and a more sustained increase in e-cigarette desire relative to the low VG cue. Both cues elicited increases in smoking urges. These results remained after controlling for sex, prior ENDS experience, recent smoking behavior, and menthol preference. CONCLUSIONS:Observation of tank-based ENDS use generalizes as a smoking cue and its cue salience is strengthened by increasing the e-liquid content of VG to enhance the visibility of the exhaled aerosol cloud.
Project description:INTRODUCTION:JUUL is an electronic cigarette (ECIG) with a compact form factor. It is prefilled with a liquid that is advertised to contain a high concentration of nicotine salt. JUUL commands 50% of the US ECIG market share, and its wide popularity with underage users has triggered unprecedented actions by the US FDA. Apart from its nicotine salt-containing liquid and compact form, a salient advertised design feature is a control circuit that limits the heating coil temperature, presumably reducing unwanted toxicants. In this study, several tobacco-flavoured JUUL devices were reverse engineered, and their aerosol emissions were studied. METHODS:Total nicotine and its partitioning (freebase and protonated), propylene glycol/vegetable glycerin (PG/VG) ratio, and carbonyls were quantified by gas chromatography (GC) and high performance liquid chromatography (HPLC). The temperature control functionality of JUUL was investigated using a temperature-controlled bath in which the coil was submerged. RESULTS:The liquid nicotine concentration was found to be 69?mg/mL, and the liquid and aerosol PG/VG ratio was found to be 30/70. In 15 puffs, JUUL emitted 2.05 (0.08) mg of nicotine, overwhelmingly in the protonated form. Carbonyl yields were significantly lower than those reported for combustible cigarettes, but similar to other closed-system ECIG devices. The heating coil resistance was 1.6 (0.66) Ohm, while the maximum power delivered by the JUUL device was 8.1 W. The control circuit limited the peak operating temperature to approximately 215C. CONCLUSIONS:JUUL emits a high-nicotine concentration aerosol predominantly in the protonated form. JUUL's nicotine-normalised formaldehyde and total aldehyde yields are lower than other previously studied ECIGs and combustible cigarettes.