Evaluation of electronic cigarette liquids and aerosol for the presence of selected inhalation toxins

An update on controversies in e-cigarettes

E-cigarettes are electronic nicotine delivery systems (ENDS) which mimic tobacco smoking without the combustion of tobacco. These devices have been misleadingly marketed as "less harmful" alternatives to conventional smoking tobacco products. The e-liquid in e-cigarettes include nicotine, a humectant and other additives including flavourings, colourants, or adulterants such as bacterial and fungal products. In this review, we discuss the contrasting views of the tobacco lobby and most professional societies. We describe the epidemiology of the use of these devices, with a widespread and significant rise in youth e-cigarette use seen in both the USA and Europe. We also describe what is known about the toxicity and mechanisms of EVALI (e-cigarette or vaping associated lung injury). This characterised by respiratory failure with an intense inflammatory response. The presentations are diverse and clinicians should consider vaping as a possible cause of any unusual respiratory illness in patients who have a history of vaping or other use of e-cigarette-related products. Second hand exposure to e-cigarettes is also harmful through respiration and transdermal absorption. E-cigarettes have a worse acute toxicity than tobacco and their long-term toxicity is unknown, and we advocate for the immediate, most vigorous anti-vaping legislation possible.

People smoke for nicotine, but lose sexual and reproductive health for tar: a narrative review on the effect of cigarette smoking on male sexuality and reproduction

PURPOSE

To systematically review the impact of smoking habits on cardiovascular (CV) as well as on male sexual and reproductive function and to provide updated evidence on the role of electronic cigarettes (e-Cig) on the same topics.

METHODS

A comprehensive Medline, Embase, and Cochrane search was performed including the following words: smoking, CV system, CV risk, erectile dysfunction (ED), and male fertility. Publications from January 1, 1969 up to February 29, 2020 were included.

RESULTS

Smoking has a tremendous negative impact on CV mortality and morbidity. Current smoking behavior is also negatively associated with erectile dysfunction (ED) and impaired sperm parameters. E-Cig can release significantly lower concentrations of harmful substances when compared to regular combustible cigarettes. Whether or not the latter can result in positive CV, sexual, and fertility outcomes is still under study. Preliminary studies showed that exposure to e-Cig leads to lower vascular damage when compared to the traditional cigarette use. However, data on the long-term effects of e-Cig are lacking. Similarly, preliminary data, obtained in animal models, have suggested a milder effect of e-Cig on erectile function and sperm parameters.

CONCLUSION

Available evidence showed that e-Cig are much less dangerous when compared to the traditional tobacco use. However, it should be recognized that the risk related to e-Cig is still higher when compared to that observed in non-smoking patients. Hence, e-Cig should be considered as a potential tool, in the logic of harm reduction, to reduce the CV, sexual and fertility risk in patients refractory to the fundamental, healthy choice to definitively quit smoking.

Smoking and Endothelial Dysfunction

Cigarette smoking is one of the most important health concerns worldwide. Even though the rate of smoking is declining in developed countries, it is still experiencing growth in developing regions. Many studies have examined the relationship between smoking, as an established risk factor, and cardiovascular diseases. We provide an updated review of the underlying mechanisms of smokinginduced cardiovascular diseases, with a focus on the relationship between smoking and oxidative stress, particularly from the perspective of endothelial cell dysfunction. We review smoking-induced oxidative stress as a trigger for a generalized vascular inflammation associated with cytokine release, adhesion of inflammatory cells and, ultimately, disruption of endothelial integrity as a protective barrier layer. We also briefly discuss the harms related to the vaping of electronic cigarettes, which many erroneously consider as a safe alternative to smoking. We conclude that even though e-cigarette could be a helpful device during the transition period of cigarette quitting, it is by no means a safe substitute.

Are In Silico Approaches Applicable As a First Step for the Prediction of e-Liquid Toxicity in e-Cigarettes?

Recent studies have raised concerns about e-cigarette liquid inhalation toxicity by reporting the presence of chemicals with European Union CLP toxicity classification. In this scenario, the regulatory context is still developing and is not yet up to date with vaping current reality. Due to the paucity of toxicological studies, robust data regarding which components in e-liquids exhibit potential toxicities, are still inconsistent. In this study we applied computational methods for estimating the toxicity of poorly studied chemicals as a useful tool for predicting the acute toxicity of chemicals contained in e-liquids. The purpose of this study was 3-fold: (a) to provide a lower tier assessment of the potential health concerns associated with e-liquid ingredients, (b) to prioritize e-liquid ingredients by calculating the e-tox index, and (c) to estimate acute toxicity of e-liquid mixtures. QSAR models were generated using QSARINS software to fill the acute toxicity data gap of 264 e-liquid ingredients. As a second step, the potential acute toxicity of e-liquids mixtures was evaluated. Our preliminary data suggest that a computational approach may serve as a roadmap to enable regulatory bodies to better regulate e-liquid composition and to contribute to consumer health protection.

The flavoring and not the nicotine content is a decisive factor for the effects of refill liquids of electronic cigarette on the redox status of endothelial cells

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The pattern of the effect on Ea.hy926 redox status differs among flavored e-liquids.

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Tobacco flavored e-liquids increase ROS generation with concomitant increase in TBARS.

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Vanilla flavored e-liquids profile depends on the nicotine content.

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Apple/mint flavored e-liquids activate the cellular antioxidant defense.

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Flavorings and not the nicotine content play a key role in free radical generation.

Electronic cigarettes are constantly gaining ground as they are considered less harmful than conventional cigarettes, and there is also the perception that they may serve as a potential smoking cessation tool. Although the acute effects of electronic cigarette use have been extensively studied, the long-term potential adverse effects on human health remain largely unknown. It has been well-established that oxidative stress is involved in the development of various pathological conditions. So far, most studies on e-cigarettes concern the effects on the respiratory system while fewer have focused on the vascular system. In the present study, we attempted to reveal the effects of electronic cigarette refill liquids on the redox state of human endothelial cells (EA.hy926 cell line). For this purpose, the cytotoxic effect of three e-liquids with different flavors (tobacco, vanilla, apple/mint) and nicotine concentrations (0, 6, 12, 18 mg/ml) were initially examined for their impact on cell viability of EA.hy926 cells. Then, five redox biomarkers [reduced form of glutathione (GSH), reactive oxygen species (ROS), total antioxidant capacity (TAC), thiobarbituric acid reactive substances (TBARS) and protein carbonyls (CARBS)] were measured. The results showed a disturbance in the redox balance in favor of free radicals in tobacco flavored e-liquids while vanilla flavored e-liquids exhibited a more complex profile depending on the nicotine content. The most interesting finding of the present study concerns the apple/mint flavored e-liquids that seemed to activate the cellular antioxidant defense and, thus, to protect the cells from the adverse effects of free radicals. Conclusively, it appears that the flavorings and not the nicotine content play a key role in the oxidative stress-induced toxicity of the e-liquids.

Breath analysis of smokers, non-smokers, and e-cigarette users

Solid phase micro extraction-Gas Chromatography/Mass Spectrometry (SPME-GC/MS) analysis was performed in exhaled breath samples of 48 healthy volunteers: 20 non-smokers, 10 smokers and 18 e-cigarette (EC, vape) users. Each volunteer provided 1 L of exhaled breath in a pre-cleaned Tedlar bag, in which an SPME fiber was exposed to absorb the emitted breath volatile organic compounds (VOCs). The acquired data were processed using multivariate data analysis (MDA) methods in order to identify the characteristic chemicals of the three groups. The results revealed that the breath of non-smokers demonstrated inverse correlation with a variety of molecules related to the breath from smokers including furan, toluene, 2-butanone and other organic substances. Vapers were distinguished from smokers by the chemical speciation of the e-liquids, such as that of esters (e.g. ethyl acetate), terpenes (e.g. α-pinene, β-pinene, d-limonene, p-cymene, etc.) and oxygenated compounds (e.g. 3-hexen-1-ol, benzaldehyde, hexanal, decanal, etc). Two classification models were developed (a) using principal component analysis (PCA) with hierarchical cluster analysis (HCA) and (b) using partial least squares-discriminant analysis (PLS-DA). Both models were validated using 8 new samples (4 vapers and 4 smokers), collected in addition to the 48 samples of the calibration set. The combination of GC/MS breath analysis and MDA contributed successfully in classifying the volunteers into their respective groups and highlighted the relevant characteristic VOCs. The respective dynamic combination (SPME-GC/MS and MDA) provides a means for long term non-invasive monitoring of the population's health status for early detection purposes.

The Impact of Device Settings, Use Patterns, and Flavorings on Carbonyl Emissions from Electronic Cigarettes

Health impacts of electronic cigarette (e-cigarette) vaping are associated with the harmful chemicals emitted from e-cigarettes such as carbonyls. However, the levels of various carbonyl compounds under real-world vaping conditions have been understudied. This study evaluated the levels of carbonyl compounds (e.g., formaldehyde, acetaldehyde, glyoxal, and diacetyl, etc.) under various device settings (i.e., power output), vaping topographies, and e-liquid compositions (i.e., base liquid, flavor types). The results showed that e-vapor carbonyl levels were the highest under higher power outputs. The propylene glycol (PG)-based e-liquids generated higher formaldehyde and acetaldehyde than vegetable glycerin (VG)-based e-liquids. In addition, fruit flavored e-liquids (i.e., strawberry and dragon fruit) generated higher formaldehyde emissions than mint/menthol and creamy/sweet flavored e-liquids. While single-top coils formed 3.5-fold more formaldehyde per puff than conventional cigarette smoking, bottom coils generated 10-10,000 times less formaldehyde per puff. In general, increases in puff volume and longer puff durations generated significantly higher amounts of formaldehyde. While e-cigarettes emitted much lower levels of carbonyl compounds compared to conventional cigarettes, the presence of several toxic carbonyl compounds in e-cigarette vapor may still pose potential health risks for users without smoking history, including youth. Therefore, the public health administrations need to consider the vaping conditions which generated higher carbonyls, such as higher power output with PG e-liquid, when developing e-cigarette product standards.

Knowledge, Attitudes, and Perceptions of Young Adults About Electronic Nicotine Delivery Systems in the United States: An Integrative Review

BACKGROUND

The causal link between cigarettes and cardiovascular disease is well known. The long-term effects of e-cigarettes are yet unknown, although early studies show biomarkers indicating inflammation and damage to endothelial cells associated with later development of cardiovascular disease. With the rapid rise in e-cigarette use, especially in young adults, it is imperative that health professionals understand the knowledge, perceptions, and motivations for use among young adults.

OBJECTIVES

The purpose of this integrative review is to explore existing literature on young adults' knowledge, attitudes, values, and perceptions about e-cigarettes, as well as the social norms they experience.

METHODS

The Whittemore and Knafl model for integrative review guided the methodology. Three databases were searched from January 2010 through December 2018. The study selection process followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Inclusion and exclusion criteria were applied. Studies were evaluated for quality and strength. Key themes were extracted, coded, and synthesized.

RESULTS

Seventy-one full-text studies were assessed for inclusion criteria; 15 articles were included, coded, and analyzed for quality and thematic content. Current e-cigarette users represented just 3% to 35% of study participants. Three themes arose from a synthesis of the literature: "Is it bad for me?," "I just like it," and "Is it cool or not?"

CONCLUSIONS

Young adults are not armed with the accurate knowledge to make informed choices about using e-cigarettes. E-cigarette users are understudied and tend to value appearance and physical sensation over health. Social norms related to e-cigarette use are linked to perception of identity and the current technology-focused culture.

A review of toxic effects of electronic cigarettes/vaping in adolescents and young adults

In this review, we examine the known and suspected toxicity of electronic cigarettes (e-cigarettes) in adolescents and young adults, to improve awareness of risks and identification of complications of their use. The use of e-cigarettes, or "vaping," is exploding among the pediatric population. E-cigarettes heat a solution containing a psychoactive compound, most commonly nicotine or tetrahydrocannabinol (THC), along with flavorings and other additives to a vapor, which users inhale. Since their introduction in the early 2000s, e-cigarette use is now prolific among youth, per the Monitoring the Future survey, with over 40% of high school seniors reporting use within the past year. Adolescents are vulnerable to the risks of e-cigarettes, as they are targeted as new consumers with advertisements and flavoring compounds, and are not utilizing them as a means to smoking cessation. The pulmonary risks of vaping are rapidly emerging, with the most immediately alarming being the condition electronic-cigarette/vaping associated lung injury (EVALI). Additionally, there have been more recent studies showing extrapulmonary effects including cardiovascular, immunologic and neuro-developmental effects. Many of these effects are likely dose-dependent. Public health efforts are urgently needed to decrease or eliminate new e-cigarette initiation, and support should be established to assist current e-cigarette users with cessation. We strongly advocate for the elimination of e-cigarette flavorings and advertising directed at adolescents, and call for physicians to be cognizant of this expanding epidemic.

Formation of Diacetyl and Other α-Dicarbonyl Compounds during the Generation of E-Vapor Product Aerosols

Exposure to diacetyl (DA) has been linked to the respiratory condition bronchiolitis obliterans. Previous research has demonstrated that DA and other α-dicarbonyl compounds can be detected in both the e-liquids and aerosols of e-vapor products (EVPs). While some EVP manufacturers may add these compounds as flavor ingredients, the primary objective of this work was to determine the potential for the formation of α-dicarbonyl compounds during the generation of aerosols from EVPs where no DA or other α-dicarbonyl compounds are added to the e-liquid. A novel ultraperformance liquid chromatography-mass spectrometry-based analytical method for the determination of DA, acetyl propionyl, glyoxal, and methylglyoxal was developed and validated. Next, eight commercially available cig-a-like-type EVPs were evaluated for α-dicarbonyl formation. Increased levels of α-dicarbonyls were observed in the aerosols of all evaluated EVPs compared to their respective e-liquids. Mechanistic studies were conducted using a model microwave reaction system to identify key reaction precursors for DA generated from propylene glycol (PG) and carbon-13-labeled glycerin (GLY). These studies, along with the corresponding retrosynthetic analysis, resulted in the proposed formation pathway where hydroxyacetone is generated from PG and/or GLY. Hydroxyacetone then participates in an aldol condensation with formaldehyde where formaldehyde can also be generated from PG and/or GLY; the resultant product then dehydrates to form DA. This proposed pathway was further investigated through in situ synthetic organic experiments within the model microwave reaction system. This work establishes that DA is formed in the aerosol generation process of the EVPs tested though at levels below toxicological concern.

A case of vaping-induced acute respiratory distress syndrome requiring extracorporeal life support

INTRODUCTION

An upsurge of e-cigarette, or vaping, product use-associated lung injury has been reported in the United States. The potential role of extracorporeal life support in e-cigarette, or vaping, product use-associated lung injury merits consideration.

CASE REPORT

We present a case of vaping-induced severe acute respiratory distress syndrome that was salvaged with extracorporeal life support and had excellent recovery.

DISCUSSION

The mechanistic reasons for the sudden outbreak of e-cigarette, or vaping, product use-associated lung injury are under active investigation. A predominantly diffuse, bilateral pattern of lung injury has been reported, with some cases meeting the criteria for severe acute respiratory distress syndrome. To date, 68 deaths from e-cigarette, or vaping, product use-associated lung injury have been confirmed by the centers of disease control. However, resolution of lung injury has been reported in most cases, thereby justifying candidacy for extracorporeal life support, if required.

CONCLUSION

Extracorporeal life support can be successfully utilized as a bridge to recovery in vaping-induced severe acute respiratory distress syndrome.

Method Validation Approaches for Analysis of Constituents in ENDS

OBJECTIVE

We assessed how many peer-reviewed publications reporting chemical quantities and/or yields from electronic nicotine delivery systems (ENDS) have included adequate method validation characteristics in the publication for appropriate interpretation of data quality for informing tobacco regulatory science.

METHODS

We searched 5 databases (Web of Knowledge, PubMed, SciFinder, Embase, EBSCOhost) for ENDS publications between January 2007 and September 2018. Of the 283 publications screened, 173 publications were relevant for analysis. We identified the publications that report a certain degree of control in data quality, ie, the publications that report marginally validated methods (MVMs). MVMs refer to the methods that: (1) report 3 or more International Conference on Harmonisation (ICH) method validation characteristics, (2) state the method was validated, (3) cite their own previous publication(s) that report MVMs, or (4) use a method within the accreditation scope of an accredited laboratory.

RESULTS

Overall, 97 publications (56%) report MVMs in their studies. This percentage also reflects the publication distribution for the majority of the 28 chemicals measured by MVMs.

CONCLUSIONS

This study highlights the need for reporting sufficient validation characteristics following appropriate guidance to ensure the accuracy and reliability of the published analytical data for proper data interpretations that may support policy.

A Social Media Study on the Associations of Flavored Electronic Cigarettes With Health Symptoms: Observational Study

Background

In recent years, flavored electronic cigarettes (e-cigarettes) have become popular among teenagers and young adults. Discussions about e-cigarettes and e-cigarette use (vaping) experiences are prevalent online, making social media an ideal resource for understanding the health risks associated with e-cigarette flavors from the users’ perspective.

Objective

This study aimed to investigate the potential associations between electronic cigarette liquid (e-liquid) flavors and the reporting of health symptoms using social media data.

Methods

A dataset consisting of 2.8 million e-cigarette–related posts was collected using keyword filtering from Reddit, a social media platform, from January 2013 to April 2019. Temporal analysis for nine major health symptom categories was used to understand the trend of public concerns related to e-cigarettes. Sentiment analysis was conducted to obtain the proportions of positive and negative sentiment scores for all reported health symptom categories. Topic modeling was applied to reveal the topics related to e-cigarettes and health symptoms. Furthermore, generalized estimating equation (GEE) models were used to quantitatively measure potential associations between e-liquid flavors and the reporting of health symptoms.

Results

Temporal analysis showed that the Respiratory category was consistently the most discussed health symptom category among all categories related to e-cigarettes on Reddit, followed by the Throat category. Sentiment analysis showed higher proportions of positive sentiment scores for all reported health symptom categories, except for the Cancer category. Topic modeling conducted on all health-related posts showed that 17 of the top 100 topics were flavor related. GEE models showed different associations between the reporting of health symptoms and e-liquid flavor categories, for example, lower association of the Beverage flavors with Respiratory compared with other flavors and higher association of the Fruit flavors with Cardiovascular than other flavors.

Conclusions

This study identified different potential associations between e-liquid flavors and the reporting of health symptoms using social media data. The results of this study provide valuable information for further investigation of the health effects associated with different e-liquid flavors.

Electronic cigarettes disrupt lung lipid homeostasis and innate immunity independent of nicotine

Electronic nicotine delivery systems (ENDS) or e-cigarettes have emerged as a popular recreational tool among adolescents and adults. Although the use of ENDS is often promoted as a safer alternative to conventional cigarettes, few comprehensive studies have assessed the long-term effects of vaporized nicotine and its associated solvents, propylene glycol (PG) and vegetable glycerin (VG). Here, we show that compared with smoke exposure, mice receiving ENDS vapor for 4 months failed to develop pulmonary inflammation or emphysema. However, ENDS exposure, independent of nicotine, altered lung lipid homeostasis in alveolar macrophages and epithelial cells. Comprehensive lipidomic and structural analyses of the lungs revealed aberrant phospholipids in alveolar macrophages and increased surfactant-associated phospholipids in the airway. In addition to ENDS-induced lipid deposition, chronic ENDS vapor exposure downregulated innate immunity against viral pathogens in resident macrophages. Moreover, independent of nicotine, ENDS-exposed mice infected with influenza demonstrated enhanced lung inflammation and tissue damage. Together, our findings reveal that chronic e-cigarette vapor aberrantly alters the physiology of lung epithelial cells and resident immune cells and promotes poor response to infectious challenge. Notably, alterations in lipid homeostasis and immune impairment are independent of nicotine, thereby warranting more extensive investigations of the vehicle solvents used in e-cigarettes.

Electronic nicotine delivery system design and aerosol toxicants: A systematic review

BACKGROUND

Electronic nicotine delivery systems (ENDS; e-cigarettes), consisting of a battery, heating element and e-liquid, have evolved significantly with wide variation in design, components, operating powers, and chemical constituents. Generated aerosols have been reported to contain potentially toxic substances. We conducted a systematic review to assess what is known about the presence of toxicants in ENDS aerosols in order to inform how system design could mitigate risk.

METHODS

Articles reporting on or evaluating design characteristics of ENDS and aerosol constituents were included and summarized.

RESULTS

The search identified 2,305 articles, of which 92 were included after full-text review. Findings were grouped into 6 major categories of potentially harmful chemicals: carbonyls, volatile organic chemicals, trace elements, reactive oxygen species and free radicals, polycyclic aromatic hydrocarbons, and tobacco-specific nitrosamines. In general, higher concentrations of aerosol toxicants are associated with increased power or voltage. Aerosol toxicants are also associated with e-liquid flavoring agents existing as primary ingredients or as products of thermal degradation.

CONCLUSIONS

Improved ENDS design can reduce toxicant levels. Additional research is needed to develop a framework for optimizing system characteristics to minimize exposure, especially with respect to heating power and e-liquids. Both manufacturers and regulatory agencies have roles in reducing toxicants and potential health risks from ENDS.

E-Cigarette Liquid Provokes Significant Embryotoxicity and Inhibits Angiogenesis

E-cigarette smoking (ECS) is a new method of tobacco smoking that is gaining popularity as it is thought to be a “healthy method” of tobacco consumption. The adverse outcomes of ECS on the respiratory and cardiovascular systems in humans have been recently demonstrated. Nevertheless, the effect of e-cigarette liquid (ECL) on the early stage of embryogenesis and angiogenesis has not been explored yet. Chicken embryo at 3 days of incubation and its chorioallantoic membrane (CAM) of 5 days were used to explore the outcome of ECL on the embryo. Real-time PCR was also employed to study the regulation of a set of key controller genes of embryogenesis as well as angiogenesis. Our study revealed that ECL exposure is associated with a high rate of mortality in embryos as around 70% of treated embryos, at 3 days of incubation, die after 5 days of exposure. Additionally, ECL inhibits angiogenesis of the CAM of 5 days of incubation by more than 30%. These effects could be explained by the upregulation of ATF-3, FOXA2, INHBA, MAPRE-2, and RIPK-1, as well as the downregulation of SERPINA-4 and VEGF-C genes, which are important key controller genes of embryogenesis as well as angiogenesis. Our data suggest clearly that ECS can have dramatic toxic outcomes on the early stage of embryogenesis as well as angiogenesis. Accordingly, we believe that further studies to assess the effects of ECS on human health are essential.

[E-cigarettes: toxicological fiasco or better than not giving up smoking?]

E‑cigarettes are increasingly used to replace tobacco cigarettes and to stop smoking, but mainly in the sense of dual use. There is lively debate about the assessment of the health risks of e‑cigarettes, but so far there are no comprehensive data for direct comparison with tobacco cigarettes. Other points of controversy include the potential for smoking cessation and the risk of moving from e‑cigarettes to tobacco cigarettes (gateway hypothesis). The present overview comes to the conclusion that, in accordance with the health policy already largely implemented in Great Britain, e‑cigarettes represent a greatly reduced health risk compared with tobacco cigarettes and are certainly suitable for giving up smoking.

Exposure to the Tobacco Power Wall Increases Adolescents' Willingness to Use E-cigarettes in the Future

INTRODUCTION

Adolescents' e-cigarette use is now more prevalent than their combustible cigarette use. Youth are exposed to e-cigarette advertising at retail point-of-sale (POS) locations via the tobacco power wall (TPW), but no studies have assessed whether exposure to the TPW influences susceptibility to future e-cigarette use.

METHODS

The study was conducted in the RAND Store Lab (RSL), a life-sized replica of a convenience store developed to experimentally evaluate how POS advertising influences tobacco use risk under simulated shopping conditions. In a between-subjects experiment, 160 adolescents (M age = 13.82; 53% female, 56% white) were randomized to shop in the RSL under one of two conditions: (1) TPW located behind the cashier (n = 80); or (2) TPW hidden behind an opaque wall (n = 80). Youths rated willingness to use e-cigarettes ("If one of your best friends were to offer you an e-cigarette, would you try it?"; 1 = definitely not, 10 = definitely yes) before and after exposure. Linear regression assessed differences in pre-post changes in willingness to use across conditions.

RESULTS

Ever-use of e-cigarettes was 5%; use of cigarettes was 8%; use of both e-cigarettes and cigarettes was 4%. There were no differences between TPW conditions on these or other baseline variables (eg, age, gender). Compared to the hidden condition, TPW exposure was associated with greater increases in willingness to use e-cigarettes in the future (B = 1.15, standard error [SE] = 0.50, p = .02).

CONCLUSIONS

Efforts to regulate visibility of the TPW at POS may help to reduce youths' susceptibility to initiating e-cigarettes as well as conventional tobacco products like cigarettes.

IMPLICATIONS

Past work suggests that exposure to the TPW in common retail settings, like convenience stores, may increase adolescents' susceptibility to smoking cigarettes. This experimental study builds upon prior research to show that exposure to the TPW at retail POS similarly increases adolescents' willingness to use e-cigarettes in the future. Efforts to regulate the visibility of the TPW in retail settings may help to reduce youths' susceptibility to initiating nicotine and tobacco products, including e-cigarettes.

Disentangling Within- and Between-Person Effects of Shared Risk Factors on E-cigarette and Cigarette Use Trajectories From Late Adolescence to Young Adulthood

BACKGROUND

Longitudinal studies report associations between use of electronic cigarettes (ECs) and cigarettes over time among young people, but do not distinguish within- from between-person effects, which complicates interpretation of findings. Further, the role of shared risk factors, such as substance use and mental health, in explaining longitudinal associations between EC and cigarette use remains unclear. This study used within- and between-person analyses to assess longitudinal associations between youths' EC and cigarette use and shared risk factors.

METHODS

Between 2015 and 2017, 2039 youths completed three Web-based surveys, allowing us to model EC and cigarette use from ages 16 to 20. Auto-regressive latent growth models with structured residuals (ALT-SR) examined both between-person and within-person associations between past-month frequency of EC use, cigarette use, and third variables (alcohol and marijuana use, mental health symptoms) over time.

RESULTS

Models revealed robust reciprocal associations between EC and cigarette use, such that more frequent EC use at one time predicted more frequent cigarette use at the subsequent time, and vice versa. Between-person analyses showed associations between shared risk factors and both EC and cigarette use. However, shared risk factors did not predict frequency of subsequent EC and cigarette use in within-person analyses.

CONCLUSIONS

Findings add to a growing body of research suggesting that EC use among youth is prospectively associated with progression toward greater cigarette use. Shared risk factors may help explain differences in EC and cigarette use patterns between young people, but do not appear to influence longitudinal trajectories of EC and cigarette use within individuals.

IMPLICATIONS

This study examined within- and between-person associations between e-cigarette use, cigarette use, and shared risk factors (alcohol use, marijuana use, mental health symptoms) in a longitudinal cohort of youths. Within- and between-person analyses revealed reciprocal prospective associations between e-cigarette and cigarette use, suggesting a progression toward more frequent use of both products over time. The shared risk factors examined here did not affect escalations in e-cigarette or cigarette use over time within individuals, but likely influence which youths use these products. Findings add to a growing body of evidence suggesting that e-cigarette use increases subsequent cigarette use in young people.

Application of High-Resolution Mass Spectrometry and a Theoretical Model to the Quantification of Multifunctional Carbonyls and Organic Acids in e-Cigarette Aerosol

Electronic (e-) cigarette aerosol (particle and gas) is a complex mixture of chemicals, of which the profile is highly dependent on device operating parameters and e-liquid flavor formulation. The thermal degradation of the e-liquid solvents propylene glycol and glycerol often generates multifunctional carbonyls that are challenging to quantify because of unavailability of standards. We developed a theoretical method to calculate the relative electrospray ionization sensitivities of hydrazones of organic acids and carbonyls with 2,4-dinitrophenylhydrazine based on their gas-phase basicities (ΔG_{deprotonation}). This method enabled quantification by high-performance liquid chromatography-high-resolution mass spectrometry HPLC-HRMS in the absence of chemical standards. Accurate mass and tandem multistage MS (MSⁿ) were used for structure identification of vaping products. We quantified five simple carbonyls, six hydroxycarbonyls, four dicarbonyls, three acids, and one phenolic carbonyl in the e-cigarette aerosol with Classic Tobacco flavor. Our results suggest that hydroxycarbonyls, such as hydroxyacetone, lactaldehyde, and dihydroxyacetone can be significant components in e-cigarette aerosols but have received less attention in the literature and have poorly understood health effects. The data support the radical-mediated e-liquid thermal degradation scheme that has been previously proposed and emphasize the need for more research on the chemistry and toxicology of the complex product formation in e-cigarette aerosols.

Arsenic species in electronic cigarettes: Determination and potential health risk

Human exposure to contaminants from electronic cigarettes (e-cigarettes) and the associated health effects are poorly understood. There has been no report on the speciation of arsenic in e-liquid (solution used for e-cigarettes) and aerosols. We report here determination of arsenic species in e-liquids and aerosols generated from vaping the e-liquid. Seventeen e-liquid samples of major brands, purchased from local and online stores in Canada and China, were analyzed for arsenic species using high-performance liquid chromatography and inductively coupled plasma mass spectrometry. Aerosols condensed from vaping the e-liquids were also analyzed and compared for arsenic species. Six arsenic species were detected, including inorganic arsenate (iAs^V), arsenite (iAs^III), monomethylarsonic acid (MMA), and three new arsenic species not reported previously. In e-liquids, iAs^III was detected in 59%, iAs^V in 94%, and MMA in 47% of the samples. In the condensate of aerosols from vaping the e-liquids, iAs^III was detected in 100%, iAs^V in 88%, and MMA in 13% of the samples. Inorganic arsenic species were predominant in e-liquids and aerosols of e-cigarettes. The concentration of iAs^III in the condensate of aerosols (median 3.27 μg/kg) was significantly higher than that in the e-liquid (median 1.08 μg/kg) samples. The concentration of inorganic arsenic in the vaping air was approximately 3.4 μg/m³, which approaches to the permissible exposure limit (10 μg/m³) set by the United States Occupational Safety and Health Administration (OSHA). According to the Environmental Protection Agency's unit risk factor (4.3 × 10^-3 per μg/m³) for inhalation exposure to inorganic arsenic in the air, the estimated excess lung cancer risk from lifetime exposure to inorganic arsenic in the e-cigarette vaping air (3.4 μg/m³), assuming e-cigarette vaping at 1% of the time, is as high as 1.5 × 10^-4. These results raise health concerns over the exposure to arsenic from electronic cigarettes.

Carbonyls and Carbon Monoxide Emissions from Electronic Cigarettes Affected by Device Type and Use Patterns

Dangerous levels of harmful chemicals in electronic cigarette (e-cigarette) aerosols were reported by several studies, but variability in e-cigarette design and use patterns, and a rapid development of new devices, such as JUUL, hamper efforts to develop standardized testing protocols and understand health risks associated with e-cigarette use. In this study, we investigated the relative importance of e-cigarette design, power output, liquid composition, puff topography on e-cigarette emissions of carbonyl compounds, carbon monoxide (CO), and nicotine. Four popular e-cigarette devices representing the most common e-cigarette types (e.g., cig-a-like, top-coil, 'mod', and 'pod') were tested. Under the tested vaping conditions, a top-coil device generated the highest amounts of formaldehyde and CO. A 'pod' type device (i.e., JUUL) emitted the highest amounts of nicotine, while generating the lowest levels of carbonyl and CO as compared to other tested e-cigarettes. Emissions increased nearly linearly with puff duration, while puff flow had a relatively small effect. Flavored e-liquids generated more carbonyls and CO than unflavored liquids. Carbonyl concentrations and CO in e-cigarette aerosols were found to be well correlated. While e-cigarettes emitted generally less CO and carbonyls than conventional cigarettes, daily carbonyl exposures from e-cigarette use could still exceed acute exposure limits, with the top-coil device potentially posing more harm than conventional cigarettes.

Chemical Characterization of Electronic Cigarette (e-cigs) Refill Liquids Prior to EU Tobacco Product Directive Adoption: Evaluation of BTEX Contamination by HS-SPME-GC-MS and Identification of Flavoring Additives by GC-MS-O

The present study focused on the determination of benzene, toluene, ethylbenzene and xylenes (BTEX) concentration levels in 97 refill liquids for e-cigs selected by the Italian National Institute of Health as representative of the EU market between 2013 and 2015 prior to the implementation of the European Union (EU) Tobacco Product Directive (TPD). Most of the e-liquids investigated (85/97) were affected by BTEX contamination, with few exceptions observed (levels below the limit of quantification (LOQ) of headspace-solid phase micro extraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) methodology). Across brands, concentration levels ranged from 2.7 to 30,200.0 µg/L for benzene, from 1.9 to 447.8 µg/L for ethylbenzene, from 1.9 to 1,648.4 µg/L for toluene and from 1.7 to 574.2 µg/L for m,p,o-xylenes. The variability observed in BTEX levels is likely to be related to the variability in contamination level of both propylene glycol and glycerol and flavoring additives included. No correlation was found with nicotine content. Moreover, on a limited number of e-liquids, gas chromatography-mass spectrometry-olfactometry (GC-MS-O) analysis was performed, allowing the identification of key flavoring additives responsible of specific flavor notes. Among them, diacetyl is a flavoring additive of concern for potential toxicity when directly inhaled into human airways. The data reported are eligible to be included in the pre-TPD database and may represent a reference for the ongoing evaluation on e-liquids safety and quality under the current EU Legislation.

Neurotoxicity of e-cigarettes

It appears that electronic cigarettes (EC) are a less harmful alternative to conventional cigarette (CC) smoking, as they generate substantially lower levels of harmful carcinogens and other toxic compounds. Thus, switching from CC to EC may be beneficial for smokers. However, recent accounts of EC- or vaping-associated lung injury (EVALI) has raised concerns regarding their adverse health effects. Additionally, the increasing popularity of EC among vulnerable populations, such as adolescents and pregnant women, calls for further EC safety evaluation. In this state-of-the-art review, we provide an update on recent findings regarding the neurological effects induced by EC exposure. Moreover, we discuss possible neurotoxic effects of nicotine and numerous other chemicals which are inherent both to e-liquids and EC aerosols. We conclude that in recognizing pertinent issues associated with EC usage, both government and scientific researchers must address this public health issue with utmost urgency.

E-cigarettes and their impact on health: from pharmacology to clinical implications

Worldwide, cigarette smoking is the major cause of premature mortality and diseases that can be prevented. Given that people continue smoking despite associated health risks, delivering nicotine without combustion should be considered a valuable and much less harmful way to reduce the public health burden caused by smoking. E‑cigarettes could play such a role if they were proven to be less harmful than combustible cigarettes. Although the number of clinical trials and human studies assessing the safety of e‑cigarettes is limited, numerous in vitro and in vivo studies reported on the potential harmful effects of the aerosol generated from e‑cigarettes. This article reviews the results of major clinical trials and laboratory studies with regard to cancer as well as cardiovascular and respiratory risk associated with the use of e‑cigarettes. Additionally, it also discusses the potential application of e‑cigarettes as smoking cessation tools. Most studies have indicated so far that e‑cigarettes are less harmful, but this applies only to smokers who completely switched to e‑cigarettes. In the opinion of the authors, good-quality research is crucial to establish the tolerance, safety, efficacy, and harm reduction potential of new technologies. Considering a significant role that physicians and other health providers play in helping smokers, there is an urgent need for evidence‑based guidelines and recommendations for clinical practitioners on potential benefits and risks of e‑cigarette use.

Effect of e-cigarette flavors on nicotine delivery and puffing topography: results from a randomized clinical trial of daily smokers

RATIONALE

There is limited understanding regarding how various e-cigarette flavorings may influence the behavior of non-regular e-cigarette users who are regular cigarette smokers.

OBJECTIVES

To assess differences in nicotine delivery, puffing topography, subjective effects, and user satisfaction from different flavored e-liquids.

METHODS

Eighteen daily smokers (average age, 44.1 ± 7.0; 9 males; average CPD, 13.0 ± 5.8) smoked their tobacco cigarettes during an initial visit and returned five times to try an e-cigarette (eGo type) refilled with a nicotine solution (24 mg/ml) of five different flavors: cherry, tobacco, espresso, menthol, and vanilla (randomized order). Assessments at each visit included puffing topography, blood samples for nicotine analysis, and subjective reports of nicotine effects and flavor satisfaction.

RESULTS

Vaping different flavors resulted in different levels of plasma nicotine. The flavor producing the highest plasma nicotine concentration (C_max) was cherry (median 21.2 ng/ml), which was not significantly different than nicotine delivery from a combustible cigarette (29.2 ng/ml, p > .05). Vanilla e-liquid produced the lowest C_max (9.7 ng/ml), and participants tended to puff less frequently on vanilla compared to tobacco flavor (p = .013). Flavors did not differ significantly in the speed of nicotine delivery (T_max). During controlled use, puff duration for all flavors was significantly longer than a combustible cigarette (p < 0.05). After controlling for nicotine delivery, significant differences in flavor enjoyment were detected. Menthol flavored e-liquid was rated as more enjoyable than vanilla and tobacco flavored e-liquids (p < 0.05).

CONCLUSIONS

Flavors tested in this study yielded different patterns of nicotine delivery and led to differences in reduction in smoking urges.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: #NCT02575885.

Association of E-Cigarette Use With Respiratory Disease Among Adults: A Longitudinal Analysis

INTRODUCTION

E-cigarettes deliver an aerosol of nicotine by heating a liquid and are promoted as an alternative to combustible tobacco. This study determines the longitudinal associations between e-cigarette use and respiratory disease controlling for combustible tobacco use.

METHODS

This was a longitudinal analysis of the adult Population Assessment of Tobacco and Health Waves 1, 2, and 3. Multivariable logistic regression was performed to determine the associations between e-cigarette use and respiratory disease, controlling for combustible tobacco smoking, demographic, and clinical variables. Data were collected in 2013-2016 and analyzed in 2018-2019.

RESULTS

Among people who did not report respiratory disease (chronic obstructive pulmonary disease, chronic bronchitis, emphysema, or asthma) at Wave 1, the longitudinal analysis revealed statistically significant associations between former e-cigarette use (AOR=1.31, 95% CI=1.07, 1.60) and current e-cigarette use (AOR=1.29, 95% CI=1.03, 1.61) at Wave 1 and having incident respiratory disease at Waves 2 or 3, controlling for combustible tobacco smoking, demographic, and clinical variables. Current combustible tobacco smoking (AOR=2.56, 95% CI=1.92, 3.41) was also significantly associated with having respiratory disease at Waves 2 or 3. Odds of developing respiratory disease for a current dual user (e-cigarette and all combustible tobacco) were 3.30 compared with a never smoker who never used e-cigarettes. Analysis controlling for cigarette smoking alone yielded similar results.

CONCLUSIONS

Use of e-cigarettes is an independent risk factor for respiratory disease in addition to combustible tobacco smoking. Dual use, the most common use pattern, is riskier than using either product alone.

A Summary of In Vitro and In Vivo Studies Evaluating the Impact of E-Cigarette Exposure on Living Organisms and the Environment

Worldwide use of electronic cigarettes has been rapidly expanding over recent years, but the long-term effect of e-cigarette vapor exposure on human health and environment is not well established; however, its mechanism of action entails the production of reactive oxygen species and trace metals, and the exacerbation of inflammation, which are associated with potential cytotoxicity and genotoxicity. The present study examines the effects of selected liquid chemicals used in e-cigarettes, such as propylene glycol/vegetable glycerin, nicotine and flavorings, on living organisms; the data collected indicates that exposure to e-cigarette liquid has potentially detrimental effects on cells in vitro, and on animals and humans in vivo. While e-liquid exposure can adversely influence the physiology of living organisms, vaping is recommended as an alternative for tobacco smoking. The study also compares the impact of e-cigarette liquid exposure and traditional cigarette smoke on organisms and the environmental impact. The environmental influence of e-cigarette use is closely connected with the emission of airborne particulate matter, suggesting the possibility of passive smoking. The obtained data provides an insight into the impact of nicotine delivery systems on living organisms and the environment.

Health Effects Associated With Electronic Cigarette Use: Automated Mining of Online Forums

Background

Our previous infodemiological study was performed by manually mining health-effect data associated with electronic cigarettes (ECs) from online forums. Manual mining is time consuming and limits the number of posts that can be retrieved.

Objective

Our goal in this study was to automatically extract and analyze a large number (>41,000) of online forum posts related to the health effects associated with EC use between 2008 and 2015.

Methods

Data were annotated with medical concepts from the Unified Medical Language System using a modified version of the MetaMap tool. Of over 1.4 million posts, 41,216 were used to analyze symptoms (undiagnosed conditions) and disorders (physician-diagnosed terminology) associated with EC use. For each post, sentiment (positive, negative, and neutral) was also assigned.

Results

Symptom and disorder data were categorized into 12 organ systems or anatomical regions. Most posts on symptoms and disorders contained negative sentiment, and affected systems were similar across all years. Health effects were reported most often in the neurological, mouth and throat, and respiratory systems. The most frequently reported symptoms and disorders were headache (n=939), coughing (n=852), malaise (n=468), asthma (n=916), dehydration (n=803), and pharyngitis (n=565). In addition, users often reported linked symptoms (eg, coughing and headache).

Conclusions

Online forums are a valuable repository of data that can be used to identify positive and negative health effects associated with EC use. By automating extraction of online information, we obtained more data than in our prior study, identified new symptoms and disorders associated with EC use, determined which systems are most frequently adversely affected, identified specific symptoms and disorders most commonly reported, and tracked health effects over 7 years.

Persistent Severe Fixed Airways Obstruction in a High-Dosing E-cigarette User

Electronic Nicotine Delivery Systems (ENDS), commonly referred to as "e-cigs," were first introduced in the United States in 2007. Since then, their use has grown substantially, with the largest market among adolescents and young adults. ENDS are often perceived by the public as safe alternatives to traditional cigarettes and as aids in smoking cessation. Little is known about inhalational hazards of e-cigs. We describe the case of a 45-year-old man who developed acute respiratory symptoms associated with onset of severe fixed airways obstruction 9 months after he quit traditional cigarettes and began high-dose vaping. Lung biopsy showed respiratory bronchiolitis. Analysis of his heated e-cigarette solution identified a mixture containing vanillin, aldehydes, alcohols and other chemicals, the inhalation effects of which have not been well-studied. This case report adds to the growing literature describing potentially severe lung health effects of vaping and provides a framework for taking a clinical vaping history so that the health consequences of e-cigarettes may be better understood.

Selected Harmful and Potentially Harmful Constituents Levels in Commercial e-Cigarettes

A broad range of commercially available electronic cigarette (e-cigarette) systems were tested for levels of emissions of harmful and potentially harmful constituents (HPHC), with a particular focus on the carbonyls: acetaldehyde, acrolein, and formaldehyde. The tobacco-specific nitrosamines N'-nitrosonornicotine and 4-(methylnitrosamino)-1-(3-bipyridyl)-1-butanone; the elements arsenic, cadmium, chromium, lead, and nickel; benzene; 1,3-butadiene; and benzo(a)pyrene were also quantified. The results show that except for the levels of carbonyls, all types of e-cigarettes performed in a similar manner, and emission levels for HPHCs were generally not quantifiable. However, levels of carbonyls, especially formaldehyde, were highly variable. Overall, the lowest levels of formaldehyde were observed in cartridge systems, which generally achieved substantial reductions in yields in comparison with cigarette smoke. Formaldehyde levels in open tank systems were variable; however, the median formaldehyde levels across different brands were substantially lower than the formaldehyde levels in cigarette smoke. The results for variable-power devices operated at the highest voltage confirmed existing literature data regardless of orientation and differences in puffing regimes. Furthermore, our results show that many products deliver consistent HPHC yields over a broad range of testing conditions (with minimal variability from one device to another, under a range of puffing conditions). However, some products exhibit high variability in emissions of HPHCs. The use of air blanks is further highlighted to assess nonproduct-related contributions to HPHC levels to avoid misrepresentation of the data. Overall, our results highlight that some but not all electronic cigarettes deliver low levels of carbonyls consistently across the full e-liquid depletion cycle under different test conditions. The need for further research and standardization work on assessment of variable-voltage electronic cigarettes is emphasized.

Life-threatening bronchiolitis related to electronic cigarette use in a Canadian youth

BACKGROUND

Although electronic cigarettes (e-cigarettes) were initially marketed as a potential smoking-cessation aid and a safer alternative to smoking, the long-term health effect of e-cigarette use ("vaping") is unknown. Vaping e-liquids expose the user to several potentially harmful chemicals, including diacetyl, a flavouring compound known to cause bronchiolitis obliterans with inhalational exposure ("popcorn worker's lung").

CASE DESCRIPTION

We report the case of a 17-year-old male who presented with intractable cough, progressive dyspnea and malaise after vaping flavoured e-liquids and tetrahydrocannabinol intensively. Initial physical examination showed fever, tachycardia, hypoxemia, and bibasilar inspiratory crackles on lung auscultation. Computed tomography of the chest showed diffuse centrilobular "tree-inbud" nodularity, consistent with acute bronchiolitis. Multiple cultures, including from 2 bronchoalveolar lavage samples, and biopsy stains, were negative for infection. He required intubation, invasive mechanical ventilation and venovenous extracorporeal membrane oxygenation (ECMO) for refractory hypercapnia. The patient's condition improved with high-dose corticosteroids. He was weaned off ECMO and mechanical ventilation, and discharged home after 47 days in hospital. Several months after hospital discharge, his exercise tolerance remained limited and pulmonary function tests showed persistent, fixed airflow obstruction with gas trapping. The patient's clinical picture was suggestive of possible bronchiolitis obliterans, thought to be secondary to inhalation of flavouring agents in the e-liquids, although the exact mechanism of injury and causative agent are unknown.

INTERPRETATION

This case of severe acute bronchiolitis, causing near-fatal hypercapnic respiratory failure and chronic airflow obstruction in a previously healthy Canadian youth, may represent vaping-associated bronchiolitis obliterans. This novel pattern of pulmonary disease associated with vaping appears distinct from the type of alveolar injury predominantly reported in the recent outbreak of cases of vaping-associated pulmonary illness in the United States, underscoring the need for further research into all potentially toxic components of e-liquids and tighter regulation of e-cigarettes.

Electronic cigarettes: where to from here?

Although the usage of electronic (e)-cigarettes (EC) and similar devices has gained in popularity as an apparent smoking cessation strategy, serious concerns are emerging in relation to both the efficacy of this strategy, as well as the inappropriate use of these devices. While the comparative safety of e-cigarettes is based on the reasonable contention that the levels of inhaled toxicants present in the aerosols generated by these devices are considerably lower than those present in tobacco smoke, the perception that they are indeed relatively risk-free is being challenged on several fronts. Notwithstanding lack of convincing evidence of efficacy as a superior smoking cessation strategy, foremost among emerging concerns is the increasing use of electronic nicotine-delivery devices by young never-smokers. Other concerns include increasing levels of sophistication in the design and capacity of these devices in relation to nicotine content and delivery, the potential threat of manipulation of the contents of e-liquids, as well as other additives such as illicit drugs and other potentially toxic agents that can be vaporised. These issues, together with the potential risks to respiratory health, specifically "e-cigarette or vaping product use-associated lung injury" represent the major thrusts of this review.

Systems toxicology assessment of a representative e-liquid formulation using human primary bronchial epithelial cells

The development of reduced-risk products aims to provide alternatives to cigarettes that present less risk of harm for adult smokers. Responsible use of flavoring substances in these products may fulfill an important role in product acceptance. While most flavoring substances used in such products are also used by the food industry and are considered safe when ingested, their impact when inhaled may require further assessment. To aid in such an assessment, a three-step approach combining real-time cellular analysis, phenotypic high-content screening assays, and gene expression analysis was developed and tested in normal human bronchial epithelial cells with 28 flavoring substances commonly used in e-liquid formulations, dissolved individually or as a mixture in a base solution composed of propylene glycol, vegetable glycerin, and 0.6% nicotine. By employing this approach, we identified individual flavoring substances that potentially contribute greatly to the overall mixture effect (citronellol and alpha-pinene). By assessing modified mixtures, we showed that, although cytotoxic effects were found when assessed individually, alpha-pinene did not contribute to the overall mixture cytotoxicity. Most of the cytotoxic effect appeared to be attributable to citronellol, with the remaining substances contributing due to synergistic effects. We developed and used different scoring methods (Tox-Score, Phenotypic Score, and Biological Impact Factor/Network Perturbation Amplitude), ultimately enabling a ranking based on cytotoxicity, phenotypic outcome, and molecular network perturbations. This case study highlights the benefits of testing both individual flavoring substances and mixtures for e-liquid flavor assessment and emphasized the importance of data sharing for the benefit of consumer safety.

E-cigarette use as a potential cardiovascular disease risk behavior

Electronic cigarette (e-cigarette) use is rapidly increasing among youth and adults despite limited information regarding the long-term risks or benefits. The potential impact of e-cigarette use on public health is complex. E-cigarettes are sometimes considered as smoking cessation aids and, to the extent that they are successful in this regard, could have a net population benefit for adult smokers. However, limited knowledge exists about the long-term health effects of e-cigarette use, and research has suggested these novel tobacco products may lead to initiation and continued use among vulnerable populations, including youth. The current review aimed to summarize trends and available scientific information about e-cigarette use, focusing on the potential cardiovascular health risks and benefits, characteristics associated with e-cigarette use, and critical areas for future investigation to inform the research and clinical work of psychologists. Psychologists have a leadership role in mitigating health risks from smoking behavior, and there is a need for rigorous research assessing the impact of e-cigarette use on population health. In addition, psychologists are uniquely qualified to understand the underlying processes regarding decision-making and behaviors around e-cigarette use. Collectively, the research of psychologists in this area can have a substantial impact on patient education, policies, and the development of prevention and intervention programs to promote public health. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Electronic cigarettes and narghile users in Brazil: Do they differ from cigarettes smokers?

BACKGROUND

Cigarette smoking prevalence is declining, however, other tobacco products have emerged recently, such as electronic cigarettes (e-cigarettes) and narghile (hookah/shisha/waterpipe). Narghile sales are not prohibited in Brazil, but e-cigarettes are. Accurate estimates of such products are key for proper monitoring and control.

OBJECTIVE

To describe the prevalence of e-cigarettes and narghile use and to investigate whether sociodemographic characteristics of individuals who are using these products differ from those who are using manufactured cigarettes.

METHODS

Using a nationally representative sample survey of Brazilians aged 12-65 years in 2015, we estimated the prevalence rates of each tobacco products within the last 12-months, stratified by macro-region, municipality size, sex-at-birth, sexual orientation, color/race, age-group, and monthly income. Multivariable logistic models were fitted to understand determinants of each tobacco product use, considering the complex sample design.

RESULTS

E-cigarette, narghile, and cigarette prevalence rates were estimated at 0.43%, 1.65% and 15.35%, respectively, corresponding to around 0.6million e-cigarette users, 2.5 million narghile users and 23.5 million cigarette users. Non-heterosexual individuals were a most-at-risk group for both e-cigarette/narghile and cigarette use. Despite similarities, e-cigarette/narghile users were younger and had higher socioeconomic status than cigarette users. Additional analyses showed that recent cigarette use seems to be more associated with e-cigarette/narghile use among youth than among adults.

CONCLUSIONS

Our findings may provide valuable information about e-cigarette/narghile use in Brazil. Prevention strategies targeted to youth to both narghile and e-cigarettes use should be implemented together, which might be one strategy to prevent the emergency of a new generation of smokers in Brazil.

Public Health Policies on E-Cigarettes

Abstract

Tobacco continues to kill about 0.48 million Americans per year and there are currently 34.3 million smokers in the USA. As a consequence of the First Surgeon General’s Report on Tobacco in 1964, tobacco control interventions on part of the government led to a significant decline in conventional tobacco product usage over the last few decades. However, more recently, a new entity in the form of electronic cigarettes has risen rapidly and has exposed a younger population to a plethora of dangerous consequences. Looking at e-cigarettes from the perspective of tobacco control however raises a lot of challenges. There is little doubt that existing smokers of combustible cigarettes who switch to e-cigarettes will be switching to a less harmful product. However, if the younger generation begins using e-cigarettes as a result of targeted marketing, appealing flavors and ‘safer alternative’ perception, decades of progress made in conventional tobacco control will be negated. Governments at the federal, state, and local levels have a mandate to once again implement new public health policies to ensure that non-conventional tobacco products like e-cigarettes are available as smoking cessation tools for existing smokers but at the same time do not play a role in ruining the health of future generations through addiction and disease.

Purpose of Review

To review the present scenario of regulations and policies impacting public health with respect to electronic nicotine delivery systems (ENDS) with the objective of providing a meaningful and balanced view of the challenges at hand with plausible recommendations.

Recent Findings

Nicotine in tobacco is known to cause addiction and dependence. It is particularly potent in children and young adults. E-cigarettes can deliver high concentrations of nicotine, and these concentrations can vary depending on the numerous constituents within the e-cigarette which vary greatly from one another. Use of e-cigarettes is implicated as a risk factor for future cigarette use in young adults. Moreover, e-cigarette usage patterns also depend on several sociodemographic factors. Banning tobacco products has shown to reduce smoking risk in youth and as such, strong e-cigarette regulation measures are needed for prevention.

Summary

Effective regulation of ENDS faces a multitude of challenges. One such challenge is to prevent youth and non-smokers from getting habituated to nicotine through e-cigarettes. The intention of tobacco companies to sustain sales through harmful marketing strategies that tone down the risks and highlight e-cigarettes as a “much safer alternative” while promoting flavors appealing to children should be immediately prohibited. Another hazard is the endorsement of ENDS as devices meant for enhancing social interaction which opens a path for youth to make erroneous choices under peer pressure. On the other hand, several studies have reported that e-cigarettes significantly reduce an existing smoker’s risk of being exposed to toxic tobacco smoke constituents that are normally present in cigarette smoke. This leads to the conclusions that e-cigarettes can be a tool for smoking cessation for current smokers. Public policy must take a multi-dimensional approach to balance these two extremes.

Developmental toxicity of e-cigarette aerosols

Maternal smoking during pregnancy represents a major public health concern increasing the risk for low birth weight, congenital anomalies, preterm birth, fetal mortality, and morbidity. In an effort to diminish adverse developmental effects of exposure to cigarette smoking, pregnant women, and women of reproductive age, are increasingly turning to electronic nicotine delivery systems (ENDS), such as e-cigarettes, as an alternative. Given that health risks associated with ENDS use during pregnancy are largely unknown, there is an acute need to determine risks vs. benefits of e-cigarette use by pregnant women. While the most recent Surgeon General's Report on the "Health Consequences of Smoking" states that "the evidence is sufficient to infer that nicotine adversely affects maternal and fetal health during pregnancy, contributing to multiple adverse outcomes," it remains unclear whether use of ENDS represents a "safer alternative" to tobacco smoking during pregnancy. This is due, in part, to the lack of sufficient and conclusive evidence concerning whether or not maternal e-cigarette use adversely affects embryonic/fetal development. While several recent developmental studies have challenged the safety of nicotine inhalation via ENDS, the true risks of smoking e-cigarettes during the first trimester of pregnancy-the period of organogenesis-are largely unknown. Moreover, evidence is emerging that even nicotine-free e-cigarette aerosols may harm the developing conceptus, suggesting that components of e-cigarette liquid, including flavorings, may be developmentally toxicity. Focused human epidemiological analyses, and carefully designed animal studies are critically needed to address the question of the safety of ENDS use during pregnancy.

The effect of e-cigarette aerosol emissions on respiratory health: a narrative review

Introduction: Due to the uptake in the use of e-cigarettes (ECs), evidence on their health effects is needed to inform health care and policy. Some regulators and health professionals have raised concerns that the respirable aerosols generated by ECs contain several constituents of potential toxicological and biological relevance to respiratory health. Areas covered: We critically assess published research on the respiratory system investigating the effects of ECs in preclinical models, clinical studies of people who switched to ECs from tobacco cigarettes, and population surveys. We assess the studies for the quality of their methodology and accuracy of their interpretation. To adequately assess the impact of EC use on human health, addressing common mistakes and developing robust and realistic methodological recommendations is an urgent priority. The findings of this review indicate that ECs under normal conditions of use demonstrate far fewer respiratory risks than combustible tobacco cigarettes. EC users and smokers considering ECs have the right to be informed about the relative risks of EC use, and to be made aware that findings of studies published by the media are not always reliable. Expert opinion: Growing evidence supports the relative safety of EC emission aerosols for the respiratory tract compared to tobacco smoke.

Should psychiatrists support the availability of nicotine e-cigarettes in Australia?

OBJECTIVE

To examine the position statement of the Royal Australian and New Zealand College of Psychiatrists (RANZCP) regarding the availability of electronic cigarettes in Australia.

CONCLUSION

There is limited evidence supporting the efficacy of nicotine e-cigarettes as an effective tobacco harm-reduction or cessation strategy for people with mental illness. The recommendations to increase their availability under regulation must be balanced with the physical and mental health risks of vapour inhalation and nicotine use, particularly for youth. Future recommendations by the RANZCP in relation to e-cigarettes must consider both the available evidence for harm reduction and the potential risks associated with youth e-cigarette use.

A proibição dos cigarros eletrônicos no Brasil: sucesso ou fracasso?

Resumo O Brasil foi um dos primeiros países do mundo a proibir os Dispositivos Eletrônicos de Fumar (DEFs), tal proibição foi motivada pela inexistência de evidências relativas às alegadas propriedades terapêuticas e da inocuidade destes produtos. Por conta de tal proibição, A Anvisa foi criticada, especialmente de grupos de usuários. Estes grupos argumentam que tal ação proibiu um produto que auxiliaria a cessação ao tabagismo e seria menos tóxico que os cigarros comuns. Assim sendo, surge o questionamento se esta decisão foi acertada ou não. Os dados disponíveis mostram que os DEFs possuem formulações diversas e algumas substâncias tóxicas são liberadas durante sua utilização em níveis significativos. Estudos em animais e em humanos demonstraram potencial efeito tóxico. Os DEFs também demostraram que podem afetar a saúde de fumantes passivos. Quanto a seu uso como ferramenta de cessação, os estudos ainda não são conclusivos. Observou-se também um alto grau de uso entre adolescentes em países que seu uso foi autorizado. Desta forma o Brasil ao proibir estes produtos, impediu que a população consumisse um produto sem comprovação que auxiliasse no tratamento do tabagismo, com indícios de significativa toxidade e altamente atrativo aos jovens.

Danger in the vapor? ECMO for adolescents with status asthmaticus after vaping

Introduction: Electronic nicotine delivery systems (ENDS) use is on the rise in the adolescent and young adult populations, especially in the wake of sweet flavored ENDS solutions and youth-targeted marketing. While the extent of effect of ENDS use and aerosolized flavorings on airway epithelium is not known, there remains significant concern that use of ENDS adversely affects airway epithelial function, particularly in populations with asthma.Case Study: In this case series, we review two cases of adolescents with history of recent and past ENDS use and asthma who required veno-venous extracorporeal membrane oxygenation (VV-ECMO) for status asthmaticus in the year 2018.Results: Both patients experienced hypercarbic respiratory failure requiring VV-ECMO secondary to their status asthmaticus, with slow recovery on extensive bronchodilator and steroid regimens. They both recovered back to respiratory baseline and were counseled extensively on cessation of ENDS use.Conclusion: While direct causation by exposure to ENDS cannot be determined, exposure likely contributed to symptoms. Based on the severity of these cases and their potential relationship with ENDS use, we advocate for increased physician screening of adolescents for ENDS use, patient and parent education on the risks of use, and family cessation counseling.

The relationship between family history of tobacco use and progression to tobacco use among young adult e-cigarette users

Family history of tobacco use and use of e-cigarettes have both been associated with increased tobacco use among young adults. However, to our knowledge, these variables have not been considered simultaneously. This study was designed to evaluate the hypothesis that family history of tobacco use would predict tobacco product use over time among young adult e-cigarette users with limited combustible tobacco use experience. A sample of 124 participants were recruited online from across the United States, completed five surveys over 12 months, and reported use of nicotine and tobacco products over the previous two weeks at each survey. Family history of nicotine and tobacco use was reported at the 6-month assessment, and data were collected in 2017 and 2018. Regression models indicated that family history was associated with likelihood of cigarette use (odds ratio = 1.02 [95% confidence interval = [1.00, 1.04]). Significant interactions between family history and linear (OR = 1.05 [1.01, 1.10]) and quadratic (OR = 0.99 (0.98, 1.00)] time terms indicated that the association between family history and likelihood of combustible product use shifted over time. In both cases, more extensive family histories predicted greater use frequency, and follow-up analyses showed that more extensive family history was associated with greater combustible tobacco product use 3, 6, and 9 months following baseline. Family history of nicotine/tobacco use may promote initiation of tobacco use among e-cigarette users. These results suggest family history of tobacco use may comprise a risk factor for combustible tobacco use within the evolving tobacco product landscape.

Electronic cigarettes in the indoor environment

The use of electronic cigarettes (e-cigarettes or "vaping") has seen an unprecedented increase worldwide. Vaping has been promoted as a beneficial smoking cessation tool and an alternative nicotine delivery device that contains no combustion by-products. However, nicotine is highly addictive, and the increased use of nicotine-containing e-cigarettes among teens and individuals who are not in need of smoking cessation may lead to overall greater nicotine dependence in the population. Furthermore, available research indicates that vaping solutions and their emissions may contain much more than just nicotine, including aerosolized flavorings, propylene glycol (PG), and other intentional and unintentional contaminants. These materials could present undefined potential health hazards to both e-cigarette users and bystanders, the full extent of which is not well understood at this time. Whereas e-cigarette usage and exposures may lower some or most of the risks associated with conventional cigarette use, the health effects of nicotine and aerosol exposures from e-cigarettes are not well understood. Research indicates that vaping aerosols are not benign, especially for nearby people in areas with limited ventilation and people with compromised health conditions. In addition, e-juice liquids have already been responsible for an increase in accidental poisonings in children. Because the magnitude of health and safety hazards that vaping may present to nonusers remains unclear, it is prudent to manage and control vaping in indoor locations where smoking is currently restricted. Based on a review of current scientific information, the American Industrial Hygiene Association (AIHA) recommends that e-cigarettes should be considered a source of aerosols, volatile organic compounds (VOCs), and particulates in the indoor environment that have not been thoroughly characterized or evaluated for health risk or safety.