Consumer Preferences for E-cigarette Flavor, Nicotine Strength, and Type: Evidence from Nielsen Scanner Data.

INTRODUCTION: Many countries regulate e-cigarette attributes such as flavors and nicotine strength. Despite a large literature on consumer preferences for e-cigarette attributes, none used consumer-level longitudinal purchase data. We therefore use a unique large dataset on U.S. adults' e-cigarette purchases as to gain insight into real-world consumer choices and purchasing patterns. METHODS: A total of 7098 purchase transactions, made by 1239 households on e-cigarette from various retail outlets for 2013 through 2017, were collected from Nielsen scanner data. We then apply an innovative multinomial logit model to examine which factors affected adult choices over 23 e-cigarettes products broken down by eight brands, three flavors, three nicotine strength levels, and two types. RESULTS: We found that tobacco flavor, medium nicotine strength (12< mg/ml ≤18), or disposables lead to higher adult purchases and such preference can vary over cigarette smoking status, purchase frequency, gender, race, and age. Specifically, smokers tend to purchase tobacco flavor, non-smokers or female vapers tend to purchase medium strength, and infrequent vapers tend to purchase disposables. Vapers are quite responsive to e-cigarette prices and also display loyalty (inertia) to e-cigarette brands, flavor, and nicotine strength. CONCLUSIONS: When modeled together, e-cigarette flavors, strength, type, price, and previous choice were all found to influence vapers' current purchase decision in the actual retail environment. IMPLICATIONS: The evidence presented here indicates that the impacts of certain restrictions on e-cigarette attributes, such as a flavor ban or maximum level of nicotine content, might have heterogeneous impacts on adults.

Vapes, E-cigs, and Mods: What Do Young Adults Call E-cigarettes?

INTRODUCTION: A diverse class of products, "e-cigarettes" present surveillance and regulatory challenges because of nonstandard terminology used to describe subtypes, especially among young adults, where occasional e-cig use is most prevalent. METHODS: Young adults (n = 3364) in wave 9 (Spring 2016) of the Truth Initiative Young Adult Cohort were randomized to see two of five photos of common e-cig products (three varieties of first-generation e-cigs and one variety each of second- and third-generation e-cigs). Qualitative responses were coded into nine classifications: "e-cigarette, e-hookah, vape-related, mod, other or more than one kind of e-cig, marijuana-related, non-e-cig tobacco product, misidentified, and don't know." We characterized the sample and survey responses and conducted multivariable logistic regression to identify participant characteristics associated with correctly identifying the devices as e-cigs. Data were weighted to represent the young adult population in the United States in 2016. RESULTS: The majority of participants identified the pictured devices as some type of e-cig (57.7%-83.6%). The white first-generation e-cig, as well as the second- and third-generation e-cigs caused the greatest confusion, with a large proportion of individuals responding "don't know" (12.2%-25.1%, depending on device) or misidentifying the e-cig as a non-nicotine product (3.4%-16.1%, depending on device) or non-e-cig tobacco product (1.4%-14.6%, depending on device). CONCLUSIONS: Accurate surveillance and analyses of the effect of e-cigs on health behavior and outcomes depend on accurate data collection on users' subtype of e-cig. Carefully chosen images in surveys may improve reporting of e-cig use in population studies. IMPLICATIONS: Survey researchers using images to cue respondents, especially young adult respondents, should consider avoiding use of white or colorful first-generation e-cigs, which were commonly misidentified in this research, in preference for black or dark colored first-generation e-cigs, such as the blu brand e-cig. Given the sizable proportion of respondents who classified second- and third-generation e-cigs with terminology related to vaping, surveys specifically aimed at assessing use of these types of e-cigs should include the term "vape" when describing this subclass of devices.

Adolescents' Use of Basic, Intermediate, and Advanced Device Types for Vaping.

Introduction: Advanced vaping devices likely pose a greater risk to adolescent health than basic or intermediate devices because advanced devices deliver nicotine more effectively and heat e-liquid to higher temperatures, producing more harmful chemical emissions. However, little is known about adolescents' risk factors for using different device types. Methods: We used social media to recruit an online sample of 1508 US adolescents aged 15-17 who reported past 30-day use of electronic vaping products (EVPs) in September 2016. We assessed tobacco use, beliefs, and knowledge about EVPs and EVP use behavior, including the device type participants use most frequently. We used multinomial logistic regression to examine differences between adolescents who usually use intermediate versus basic and advanced versus basic devices. Results: Most respondents usually used modifiable advanced devices (56.8%) rather than basic "cigalike" (14.5%) or pen-style intermediate (28.7%) devices. Use of multiple device types was common, particularly among those who primarily used basic devices. Younger age and less frequent vaping were associated with mainly using basic devices. Adolescents who were older, male, personally bought their main device, and had ever mixed e-liquids were at elevated risk for usually using advanced devices. Conclusions: Adolescents who primarily use basic devices may be newer users who are experimenting with multiple devices. Future research should examine which adolescents are most likely to transition to advanced devices in order to develop targeted interventions. Regulators should consider strategies to reduce access to all types of EVPs, such as better enforcement of the current ban on sales to minors. Implications: This research addresses two gaps in research on adolescent electronic vaping product use: (1) characterizing use of advanced devices as distinct from intermediate devices rather than grouping them together and (2) examining factors associated with use of specific device types. This study suggests that there are distinct profiles of adolescents who use primarily basic, intermediate, or advanced devices. Adolescents who most often use basic devices may be new users experimenting with vaping, whereas adolescents who most often use advanced devices appear to be buying devices for themselves and engaging in risky behaviors such as mixing their own e-liquid.

Toxicity classification of e-cigarette flavouring compounds based on European Union regulation: analysis of findings from a recent study.

INTRODUCTION: A recent study raised concerns about e-cigarette liquids toxicity by reporting the presence of 14 flavouring chemicals with toxicity classification. However, the relevant toxicity classification was not estimated according to the measured concentrations. The purpose of this study was to calculate the toxicity classification for different health hazards for all the flavouring chemicals at the maximum concentrations reported. METHODS: The analysis was based on the European Union Classification Labelling and Packaging regulation. The concentration of each flavouring chemical was compared with the minimum concentration needed to classify it as toxic. Additionally, toxicity classification was examined for a theoretical e-cigarette liquid containing all flavouring chemicals at the maximum concentrations reported. RESULTS: There was at least one toxicity classification for all the flavouring chemicals, with the most prevalent classifications related to skin, oral, eye and respiratory toxicities. One chemical (methyl cyclopentenolone) was found at a maximum concentration 150.7% higher than that needed to be classified as toxic. For the rest, the maximum reported concentrations were 71.6 to > 99.9% lower than toxicity concentrations. A liquid containing all flavouring compounds at the maximum concentrations would be classified as toxic for one category only due to the presence of methyl cyclopentenolone; a liquid without methyl cyclopentenolone would have 66.7 to > 99.9% lower concentrations of flavourings than those needed to be classified as toxic. CONCLUSIONS: The vast majority of flavouring compounds in e-cigarette liquids as reported in a recent study were present at levels far lower than needed to classify them as toxic. Since exceptions exist, regulatory monitoring of liquid composition is warranted.

Type of E-Cigarette Device Used Among Adolescents and Young Adults: Findings From a Pooled Analysis of Eight Studies of 2166 Vapers.

Background: A recent study of adult smokers who vape found that disposable/cigalike electronic (e-) cigarette devices were more commonly used than later generation devices. However, whether these trends reflect patterns among adolescents and young adults, many of whom have limited or no history of combustible cigarette use, has not been studied. Methods: Participants were drawn from eight locally, regionally, and US nationally representative studies. Surveys took place between Fall 2014 and Spring 2016; participants were residents of California (3 studies), Texas (2 studies), Connecticut (1 study), or randomly selected from the US population (2 studies). Data were collected from middle and high school students (4 studies), young adults under 30 (3 studies), or a mixture (1 study) to assess type of e-cigarette device used among past-30 day e-cigarette users: disposable/cigalike, or later generation e-cigarette device. Results: Fewer than 15% of participants in each study reported primarily using a disposable/cigalike device in the past month (across all studies: 7.5%; 95%CI: 4.9%, 10.5%). The proportion using later generation devices ranged from 58% to 86% across studies; overall, 77.0% (95%CI: 70.5%, 82.9%) reported primary use of a later generation device. Combined, 13.2% (95%CI: 5.9%, 22.8%) reported "don't know" or were missing data. Conclusions: Among adolescent and young adult e-cigarette users, primary use of disposable/cigalike devices was rare. Future research should continue to evaluate the type of device used by adolescents and young adults, as these data may be relevant to regulatory oversight of e-cigarettes recently acquired by the Food and Drug Administration Center for Tobacco Products. Implications: In this pooled analysis of adolescent and young adult vapers, primary use of later generation e-cigarette devices was substantially more common than use of disposable/cigalike devices. The type of device predominantly used by adolescents and young adults has regulatory implications for policy to reduce adolescent use of e-cigarettes.

Trends in Unit Sales of Flavored and Menthol Electronic Cigarettes in the United States, 2012-2016.

INTRODUCTION: The use of flavored tobacco products, including electronic cigarettes (e-cigarettes), is common in the United States, and flavored products are particularly appealing to young people. The objective of this study was to describe national and state trends in flavored and menthol e-cigarette unit sales. METHODS: We examined data on 4 types of e-cigarette products (rechargeables, disposables, prefilled cartridges, and e-liquid refills). We used Universal Product Code retail scanner data from 2 sources: 1) convenience stores and 2) all other outlets combined, including supermarkets, drug stores, mass merchandisers (including Walmart), dollar stores, club stores, and US Department of Defense commissaries. We aggregated data in 4-week periods for the 48 contiguous states and the District of Columbia for the 5-year period from 2012 through 2016. Data from vape shops and internet sales were not available. We used Joinpoint regression to assess trends. RESULTS: From 2012 through 2016, flavored e-cigarette sales as a percentage of all e-cigarette sales increased nationally (from 2.4% to 19.8%) and in all but 4 states (North Dakota, South Dakota, Utah, and Vermont). Nationally, flavored disposable and prefilled cartridge sales increased. Menthol e-cigarette sales were stable nationally at 35% to 40%, while the percentage of menthol disposable, prefilled cartridge, and e-liquid refill sales decreased. By state, menthol e-cigarette sales increased in 2 states (Idaho and Nebraska) and decreased in 7 states. During 2015-2016, the percentage of flavored sales decreased in one state (Rhode Island) and increased in 29 states. CONCLUSION: These findings demonstrate that sales of flavored e-cigarette products have increased dramatically since 2012, with variations by product type and state. Continued monitoring of sales trends at all retail outlets can inform federal, state, and local efforts to address flavored tobacco product use, including e-cigarettes, in the United States.

National and State-Specific Unit Sales and Prices for Electronic Cigarettes, United States, 2012-2016.

INTRODUCTION: Few studies have explored patterns of electronic cigarette (e-cigarette) sales and prices by product type over time. We used US retail scanner data to assess national and state-specific trends in e-cigarette unit sales and prices for 4 product types sold from 2012 through 2016. METHODS: Using retail scanner data from the 48 contiguous states and Washington, DC, for convenience stores; supermarkets; mass merchandisers; drug, dollar, and club stores; and military commissaries, we assessed data on monthly unit sales and inflation-adjusted prices by 4 products (rechargeables, disposables, prefilled cartridges, and e-liquids) sold during the 5-year study period. We evaluated national and state trends by using Joinpoint regression (P < .05). RESULTS: From 2012 through 2016, average national monthly unit sales significantly increased for all products, while average monthly prices of rechargeables, disposables, and prefilled cartridges significantly decreased. In 2016, prefilled cartridges had the highest average sales (766 units per 100,000 people) and the lowest average price ($14.36 per unit). By state, average monthly sales significantly increased for at least 1 of 4 e-cigarette products in all 48 states and Washington, DC. However, during the same period, average monthly prices significantly decreased in 39 states for rechargeables, in 31 states for disposables, in 20 states for prefilled cartridges, and in 8 states for e-liquids. CONCLUSION: Overall, US e-cigarette unit sales generally increased as product prices decreased. These findings demonstrate the rapidly evolving landscape of US e-cigarette retail marketplace. Ongoing surveillance of e-cigarette unit sales and price is critical for informing and evaluating evidence-based tobacco control strategies.

E-cigarettes as a source of toxic and potentially carcinogenic metals.

BACKGROUND AND AIMS: The popularity of electronic cigarette devices is growing worldwide. The health impact of e-cigarette use, however, remains unclear. E-cigarettes are marketed as a safer alternative to cigarettes. The aim of this research was the characterization and quantification of toxic metal concentrations in five, nationally popular brands of cig-a-like e-cigarettes. METHODS: We analyzed the cartomizer liquid in 10 cartomizer refills for each of five brands by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). RESULTS: All of the tested metals (cadmium, chromium, lead, manganese and nickel) were found in the e-liquids analyzed. Across all analyzed brands, mean (SD) concentrations ranged from 4.89 (0.893) to 1970 (1540) µg/L for lead, 53.9 (6.95) to 2110 (5220) µg/L for chromium and 58.7 (22.4) to 22,600 (24,400) µg/L for nickel. Manganese concentrations ranged from 28.7 (9.79) to 6910.2 (12,200) µg/L. We found marked variability in nickel and chromium concentration within and between brands, which may come from heating elements. CONCLUSION: Additional research is needed to evaluate whether e-cigarettes represent a relevant exposure pathway for toxic metals in users.

The importance of product definitions in US e-cigarette laws and regulations.

BACKGROUND: How electronic cigarettes and similar products (e-cigarettes) are defined affects how they are regulated, particularly whether existing laws for cigarettes apply, including sales and marketing, youth access, smoke-free and taxation laws. METHODS: We examined the text of 46 bills that define e-cigarettes enacted in 40 states and characterised how e-cigarettes and similar products were defined. RESULTS: States enact laws creating new product categories for e-cigarettes separate from the 'tobacco product' category (eg, 'alternative nicotine product,' 'vapour product,' 'electronic nicotine device'), with four states explicitly excluding e-cigarettes from 'tobacco products.' Twenty-eight states do not include e-cigarettes in their definitions of 'tobacco products' or 'smoking,' eight include e-cigarettes as 'tobacco products,' three include e-cigarettes in 'smoking.' Sixteen states' definitions of e-cigarettes require nicotine, and five states pre-empt more stringent local laws. Tobacco and e-cigarette industry representatives tried to shape laws that benefit their interests. CONCLUSIONS: Definitions separating e-cigarettes from other tobacco products are common. Similar to past 'Trojan horse' policies, e-cigarette policies that initially appear to restrict sales (eg, limit youth access) may actually undermine regulation if they establish local pre-emption or create definitions that divide e-cigarettes from other tobacco products. Comparable issues are raised by the European Union Tobacco Products Directive and e-cigarette regulations in other countries. Policymakers should carefully draft legislation with definitions of e-cigarettes that broadly define the products, do not require nicotine or tobacco, do not pre-empt stronger regulations and explicitly include e-cigarettes in smoke-free and taxation laws.

Who is JUULing and Why? An Examination of Young Adult Electronic Nicotine Delivery Systems Users.

PURPOSE: The purpose of this study was to compare characteristics of usual JUUL users versus other electronic nicotine delivery systems (ENDS) users, examine differences in reasons for use and perceptions across ENDS user groups, and identify significant correlates of usual JUUL use. METHODS: This study used data from 510 young adult ENDS users (ages 18-29 years) from Wave 7 (Spring 2018) of the Marketing and Promotions Across Colleges in Texas Project (Project M-PACT). Chi-Square analyses, independent t-tests, and mixed-effects logistic regression analyses were conducted to identify factors associated with usual JUUL use. Four separate regression analyses were conducted based on independent variables of interest; all models included demographics and ENDS/other tobacco use behaviors as covariates. RESULTS: Compared with other ENDS users, usual JUUL users were more likely to be male, younger, smoke cigarettes, reported a higher socioeconomic status (SES), used ENDS on more days in the past 30 days, and reported nicotine "hit" as a reason for use. Usual JUUL users had a higher prevalence of perceiving JUUL/pod vapes as addictive compared with other ENDS users, although perceived addictiveness was not significant in the multivariable models nor were the cessation and dependence measures different between ENDS user groups. CONCLUSIONS: Results highlight concerns about the dual use of JUUL and cigarettes and raise additional concerns about the high nicotine concentration of JUUL. Future longitudinal research is needed to determine if usual JUUL users are more likely to develop symptoms of nicotine dependence compared with other ENDS users.

Could E-cigarette vaping contribute to heart disease?

INTRODUCTION: E-cigarettes have become a controversial topic. While their benefits are questioned by the scientific community, a part of the medical profession is still supporting them as an effective harm reduction tool for smoking cessation. The impact of E-cigarettes on the cardiovascular system is still elusive. AREAS COVERED: We assessed results from animal, pre(clinical), and epidemiological studies to critically evaluate and synthesize evidence relevant to the cardiovascular effects of E-cigarettes. Animal studies have demonstrated that E-cigarette vapor exposure can cause endothelial and cardiac dysfunction. However, there have also been reports on the less harmful effects of E-cigarette vapor exposure in comparison to classical tobacco cigarettes. Measurements of flow-mediated dilation in acute human exposure settings have mostly demonstrated that E-cigarettes cause vascular endothelial dysfunction. Epidemiological studies have shown that E-cigarette use is associated with an increased risk for cardiovascular disease, although switching from classical tobacco cigarettes to E-cigarettes can have beneficial cardiovascular effects. Misinterpretation of scientific data by activists on either side is another problem. EXPERT OPINION: In conclusion, we need more and better (pre)clinical data comparing the health effects of E-cigarette vaping as compared with tobacco cigarette smoking, in order to counsel the legislation for better health policies.

Tobacco and electronic cigarette cues for smoking and vaping: an online experimental study.

OBJECTIVE: This study examined whether exposure to smoking and vaping cues the urge to smoke or vape. It extends previous studies on first-generation cigalikes (visually similar to cigarettes) and second-generation devices (visually similar to pens) by including third-generation tank system devices (larger bulky units). In an online experiment, participants were randomly assigned to view one of four videos, which included smoking, vaping (cigalike or tank system), or neutral cues. The primary outcome was urge to smoke. Secondary outcomes were urge to vape, desire to smoke and vape, and intention to quit or remain abstinent from smoking. RESULTS: UK adults varying in smoking (current or former) and vaping (user or non-user) status (n = 1120) completed the study: 184 (16%) failed study attention checks meaning 936 were included in the final analysis. Urges to smoke were similar across cue groups. Urges to vape were higher following exposure to vaping compared to neutral cues. There was no clear evidence of an interaction between cue group and smoking or vaping status. The lack of cueing effects on smoking urges is inconsistent with previous research, raising questions about the ability to assess craving in online settings.

Association between preference for using alcohol beverage-named e-liquids and alcohol use among high school youth.

BACKGROUND: There are thousands of e-liquid flavors available, and some are named after alcohol beverages (e.g., "pina colada"). It is unclear whether use of e-liquids with alcohol beverage names is associated with adolescent alcohol use. E-cigarettes and alcohol are co-used in adolescents; therefore, it is important to investigate these associations. METHODS: Eight Southeastern Connecticut high schools were surveyed in Spring 2015 (N = 7045). We examined the association between preference for using e-liquid flavors and alcohol drinking status (i.e., no past month alcohol use, past month alcohol use but no binge drinking, and past month binge drinking) in ever e-cigarette users (N = 1311). RESULTS: Among ever e-cigarette users who preferred using e-liquids with alcohol beverage names (N = 111), 30.6 % had no past month alcohol use, 19.8 % had past month alcohol use but did not binge drink in the past month, and 49.5 % binge drank in the past month. Multinomial logistic regression (controlling for demographics and including other e-cigarette flavors that were highly endorsed, i.e., fruit and candy) revealed that the preferences of alcohol beverage-named-e-liquid (OR: 2.84, CI: 1.70-4.75) and fruit flavored e-liquids (OR: 1.55, CI: 1.14-2.11), but not candy flavored e-liquids was associated with past-month binge drinking compared to no past-month alcohol use. CONCLUSION: This evidence suggests that the preference for using alcohol beverage- and fruit-named e-liquid flavors is associated with past-month binge drinking among adolescents. Understanding the associations between alcohol beverage-named e-liquids and alcohol use in adolescents may help inform tobacco regulatory strategies that aim to decrease the use/appeal of e-cigarettes.

Nicotine absorption during electronic cigarette use among regular users.

BACKGROUND: The capability of electronic cigarette devices (e-cigs) to deliver nicotine is key to their potential to replace combustible cigarettes. We compared nicotine delivery and subjective effects associated with the use of two classes of e-cigarettes and cigarettes. METHODS: 14 e-cigarette users were instructed to vape their own e-cigarette device every 20 seconds for 10 minutes while blood was drawn at 1, 2, 4, 6, 8, 10,12, and 15 minutes after initiating vaping. Users rated withdrawal symptoms and side effects before and after vaping. E-cigarette devices were classified as first-generation (same size as cigarette, no activation button) or advanced (larger than cigarette with an activation button). Separately, 10 cigarette smokers completed a similar protocol. Fisher's Exact Test and two-sided t-tests were used as appropriate to determine differences in outcomes between first-generation e-cigarette users, advanced e-cigarette users, and smokers. RESULTS: Compared to first-generation devices, advanced devices were associated with greater serum nicotine Cmax (ng/ml) (11.5 v. 2.8, p = 0.0231) and greater nicotine boost (ng/ml) (10.8 v. 1.8, p = 0.0177). Overall, e-cigarettes users experienced a significant reduction in withdrawal and craving, although there were no significant differences between users of first-generation and advanced devices. Comparing e-cigarettes overall to cigarettes, cigarettes were associated with greater Cmax (25.9 v. 9.0, p = 0.0043) and greater nicotine boost (21.0 v. 8.2, p = 0.0128). CONCLUSIONS: Advanced e-cigarettes delivered significantly more nicotine than first-generation devices but less than combustible cigarettes. Overall, e-cigarette use was associated with a reduction in withdrawal and craving with no reported side effects. The wide variation in nicotine absorption from different e-cigarette devices should be considered in studies of e-cigarettes for smoking cessation.

Electronic nicotine delivery system landscape in licensed tobacco retailers: results of a county-level survey in Oklahoma.

OBJECTIVES: Electronic nicotine delivery systems (ENDS) have recently emerged as a component of the tobacco retail environment. The aims of this study were to describe the availability, types of ENDS and placement of ENDS relative to traditional tobacco products at franchised licensed tobacco retailers and non-franchised licensed tobacco retailers. DESIGN: Observational study. SETTING: Franchised and non-franchised tobacco retailers in Cleveland County, Oklahoma, USA. PRIMARY AND SECONDARY OUTCOME MEASURES: The number of stores selling ENDS, the variability in brands of ENDS sold, the location of the ENDS within the retailers, the quantity of ENDS sold compared with traditional tobacco products, and the presence of outdoor signage. RESULTS: Data from 57 randomly sampled tobacco retailers were used to describe the presence of ENDS at independent non-franchised and franchised tobacco retailers. The overwhelming majority (90%) of licensed tobacco retailers sold ENDS, and differences were observed between franchised and non-franchised stores. 45 of the 51 retailers (88%) selling ENDS had them placed at the point of sale. 2 of the 21 franchised retailers (9.5%) had ENDS placed at ≤3½ feet above floor level compared to none of the 30 non-franchised retailers (0%). CONCLUSIONS: This small study is the first to characterise ENDS within the tobacco retail environment in a county in Oklahoma, USA. The results from this study demonstrate the complexity of the tobacco retail landscape and generate questions for future studies regarding the incorporation and placement of ENDS in tobacco retail environments.

Vapours of US and EU Market Leader Electronic Cigarette Brands and Liquids Are Cytotoxic for Human Vascular Endothelial Cells.

The present study was conducted to provide toxicological data on e-cigarette vapours of different e-cigarette brands and liquids from systems viewed as leaders in the e-cigarette market and to compare e-cigarette vapour toxicity to the toxicity of conventional strong high-nicotine cigarette smoke. Using an adapted version of a previously constructed cigarette smoke constituent sampling device, we collected the hydrophilic fraction of e-cigarette vapour and exposed human umbilical vein endothelial cells (HUVECs) to the mixture of compounds present in the vapour of 4 different single-use e-cigarettes, 6 different liquid vapours produced by the same refillable e-cigarette, and one e-cigarette with an exchangeable liquid cartridge. After incubation of cells with various concentrations and for various periods of time we analysed cell death induction, proliferation rates, the occurrence of intra-cellular reactive oxygen species, cell morphology, and we also measured e-cigarette heating coil temperatures. Overall, conventional cigarette smoke extract showed the most severe impact on endothelial cells. However, some e-cigarette vapour extracts showed high cytotoxicity, inhibition of cell proliferation, and alterations in cell morphology, which were comparable to conventional high-nicotine cigarettes. The vapours generated from different liquids using the same e-cigarette show substantial differences, pointing to the liquids as an important source for toxicity. E-cigarette vapour-mediated induction of oxidative stress was significant in one out of the 11 analysed vapours. There is a high variability in the acute cytotoxicity of e-cigarette vapours depending on the liquid and on the e-cigarettes used. Some products showed toxic effects close to a conventional high-nicotine cigarette. Liquid nicotine, menthol content, and the formation of acute intracellular reactive oxygen species do not seem to be the central elements in e-cigarette vapour toxicity.

Secondhand exposure to aerosol from electronic cigarettes: pilot study of assessment of tobacco-specific nitrosamine (NNAL) in urine / Exposición pasiva al aerosol del cigarrillo electrónico: estudio piloto de evaluación de la nitrosamina específica del tabaco (NNAL) en orina

Objective: To assess the levels of a tobacco-specific nitrosamine (NNAL) in non-smokers passively exposed to the second-hand aerosol (SHA) emitted from users of electronic cigarettes (e-cigarettes). Method: We conducted an observational study involving 55 non-smoking volunteers divided into three groups: 25 living at home with conventional smokers, 6 living with e-cigarette users, and 24 in control homes (smoke-free homes). We obtained urine samples from all volunteers to determine NNAL. Results: We detected NNAL in the urine of volunteers exposed to e-cigarettes (median:0.55 pg/mL; interquartile range: 0.26-2.94 pg/mL). The percentage of urine samples with quantifiable NNAL differed significantly among the three groups of homes: 29.2%, 66.7% and 76.0%, respectively (p=0.004). Conclusions: We found NNAL nitrosamine in urine samples from people exposed to SHA from e-cigarettes. However, these results could be confirmed with more studies with larger sample sizes

Objetivo Evaluar los niveles de nitrosamina específica del tabaco (NNAL) en no fumadores expuestos pasivamente al aerosol emitido por usuarios de cigarrillo electrónico. Método: Estudio observacional de una muestra de 55 voluntarios no fumadores divididos en tres grupos: 25 que vivían en una casa con un fumador de tabaco convencional, 6 que vivían en una casa con un usuario de cigarrillo electrónico y 24 que vivían en casas controles (hogares libres de humo). Se obtuvo una muestra de orina de todos los voluntarios para determinar las concentraciones de NNAL. Resultados: Se detectaron valores de NNAL en los voluntarios expuestos al cigarrillo electrónico (mediana: 0,55 pg/ml; rango intercuartílico: 0,26-2,94 pg/ml). El porcentaje de voluntarios con concentraciones cuantificables de NNAL fue estadísticamente diferente entre los tres grupos de casas: 29,2%, 66,7% y 76%, respectivamente (p=0,004). Conclusiones: Se encontraron valores de NNAL en los no fumadores expuestos pasivamente al aerosol del cigarrillo electrónico. Estos resultados tienen que confirmarse con muestras más grandes