Background: The use of electronic cigarettes has become increasingly popular in recent years. However, the impact that electronic cigarettes have on the ocular surface is not well known. Therefore, the aim of this review is to explore the current literature on the acute and chronic sequelae of electronic cigarettes on the ocular surface. Methods: A systematic review of the literature was undertaken by keyword searching on the Embase, Medline, and Web of Science databases. Articles identified through the search underwent title/abstract screening, full-text screening, and data extraction. Results: A total of 18 studies were included in this review. Non-intended ocular surface exposures and intended exposures on the ocular surface were found to be associated with the use of electronic cigarettes. Conclusions: The impact of vaping on the ocular surface is not benign. There are significant risks that vaping can pose to the ocular surface. Hence, it is necessary to develop appropriate risk communication tools given the increasing popularity of this activity. Additionally, future long-term studies are needed to better understand the long-term impacts of vaping on the ocular surface given the lack of current data.

In recent years, the use of electronic vaping products (also named e-cigarettes) has increased due to their appealing flavors and nicotine delivery without the combustion of tobacco. Although the hazardous substances emitted by e-cigarettes are largely found to be much lower than combustible cigarettes, second-hand exposure to e-cigarette aerosols is not completely benign for bystanders. This work reviewed and synthesized findings on the second-hand exposure of aerosols from e-cigarettes and compared the results with those of the combustible cigarettes. In this review, different results were integrated based upon sampling locations such as residences, vehicles, offices, public places, and experimental exposure chambers. In addition, the factors that influence the second-hand exposure levels were identified by objectively reviewing and integrating the impacts of combustible cigarettes and e-cigarettes on the environment. It is a challenge to compare the literature data directly to assess the effect of smoking/vaping on the indoor environment. The room volume, indoor air exchange rate, puffing duration, and puffing numbers should be considered, which are important factors in determining the degree of pollution. Therefore, it is necessary to calculate the \"emission rate\" to normalize the concentration of pollutants emitted under various experimental conditions and make the results comparable. This review aims to increase the awareness regarding the harmful effects of the second-hand exposure to aerosols coming from the use of cigarettes and e-cigarettes, identify knowledge gaps, and provide a scientific basis for future policy interventions with regard to the regulation of smoking and vaping.

E-cigarettes have rapidly gained popularity among youth in recent years. This scoping review identifies opportunities for school nurses to incorporate e-cigarette prevention strategies into their practice and identifies gaps for future research in school nursing evidence-based practice. Using the methodological framework developed by Arksey and O\'Malley and advanced by Levac et al., a literature review was conducted using PubMed, Cumulative Index to Nursing and Allied Health (CINAHL), and Education Resources Information Center (ERIC) databases. A total of 15 articles were included in the final review. Articles for inclusion addressed interventions aimed at reducing e-cigarette use in K-12 schools. The results highlight two general types of school-based interventions: (1) universal e-cigarette prevention education and (2) targeted e-cigarette use-cessation programs. Each of these types of interventions presents a leadership opportunity for school nurses to engage within all domains of their scope of practice.

Tobacco harm reduction is a public health approach to reduce the impact of cigarette smoking on individuals. Non-combustible alternatives to cigarettes, such as electronic cigarettes (e-cigarettes), deliver nicotine to the user in the absence of combustion. The absence of combustion in e-cigarettes reduces the level of harmful or potentially harmful chemicals in the aerosol generated. This narrative review examines the published literature that studied the chemistry of e-cigarette aerosols, the related toxicology in cell culture and animal models, as well as clinical studies that investigated short- and long-term changes in biomarkers of smoke exposure after switching to e-cigarettes. In the context of the literature reviewed, the evidence supports the harm reduction potential for adult smokers who switch to e-cigarettes.

To date only a limited number of reviews have focused on how exposure and outcome measures are defined in the existing literature on associations between tobacco retailer density (\'density\') and smoking behaviour (\'smoking\'). Therefore this systematic review classified and summarised how both density and smoking variables are operationalised in the existing literature, and provides several methodological recommendations for future density and smoking research.
Two literature searches between March and April 2018 and April 2022 were conducted across 10 databases. Inclusion and exclusion criteria were developed and keyword database searches were undertaken. Studies were imported into Covidence. Cross-sectional studies that met the inclusion criteria were extracted and a quality assessment was undertaken. Studies were categorised according to the density measure used, and smoking was re-categorised using a modified classification tool.
Large heterogeneity was found in the operationalisation of both measures in the 47 studies included for analysis. Density was most commonly measured directly from geocoded locations using circular buffers at various distances (n = 14). After smoking was reclassified using a smoking classification tool, past-month smoking was the most common smoking type reported (n = 26).
It is recommended that density is measured through length-distance and travel time using the street network and weighted (e.g. by the size of an area), or by using Kernel Density Estimates as these methods provide a more accurate measure of geographical to tobacco and e-cigarette retailer density. The consistent application of a smoking measures classification tool, such as the one developed for this systematic review, would enable better comparisons between studies. Future research should measure exposure and outcome measures in a way that makes them comparable with other studies.
This systematic review provides a strong case for improving data collection and analysis methodologies in studies assessing tobacco retailer density and smoking behaviour to ensure that both exposure and outcome measures are clearly defined and captured. As large heterogeneity was found in the operationalisation of both density and smoking behaviour measures in the studies included for analysis, there is a need for future studies to capture, measure and classify exposure measures accurately, and to define outcome measures in a manner that makes them comparable with other studies.

UNASSIGNED: E-cigarettes have emerged as a popular alternative to traditional tobacco smoking in recent years. Despite their growing popularity, concerns have arisen regarding the cardiovascular implications of e-cigarette use.
UNASSIGNED: This narrative review aims to highlight the latest evidence on the impact of e-cigarettes on cardiovascular health.
UNASSIGNED: Numerous studies have demonstrated that e-cigarette use can lead to acute adverse cardiovascular effects. Inhalation of e-cigarette aerosols exposes users to a wide range of potentially harmful substances that have been implicated in critical pathophysiologic pathways of cardiovascular disease, namely endothelial dysfunction, oxidative stress, inflammation, sympathetic overdrive, and arterial stiffness. While long-term epidemiological studies specifically focusing on the cardiovascular effects of e-cigarettes are still relatively scarce, early evidence suggests a potential association between e-cigarette use and an increased risk of adverse cardiovascular events. However, it is essential to recognize that e-cigarettes are relatively new products, and the full extent of their long-term cardiovascular impact has not been fully elucidated. In the meantime, promoting tobacco cessation strategies that are evidence-based and regulated, along with rigorous monitoring of e-cigarette use patterns and associated health outcomes, are essential steps in safeguarding cardiovascular health in the face of this emerging public health challenge.

Electronic cigarette use has grown exponentially in recent years, and while their popularity has increased, the long-term effects on the heart are yet to be fully studied and understood. Originally designed as devices to assist with those trying to quit traditional combustible cigarette use, their popularity has attracted use by teens and adolescents who traditionally have not smoked combustible cigarettes. Acute effects on the heart have been shown to be similar to traditional combustible cigarettes, including increased heart rate and blood pressure. The main components of electronic cigarettes that contribute to these arrhythmic effects are found in the e-liquid that is aerosolized and inhaled, comprised of nicotine, flavourings, and a combination of vegetable glycerin (VG) and propylene glycol (PG). Nicotine can potentially induce both ventricular and atrial arrhythmogenesis, with both the atrial and ventricular effects resulting from the interactions of nicotine and the catecholamines they release via potassium channels. Atrial arrhythmogenesis, more specifically atrial fibrillation, can also occur due to structural alterations, which happens because of nicotine downregulating microRNAs 133 and 590, both post-transcriptional growth factor repressors. Liquid flavourings and the combination of PG and VG can possibly lead to arrhythmic events by exposing users to acrolein, an aldehyde that stimulates TRPA1 that in turn causes a change towards sympathetic activation and autonomic imbalance. The design of these electronic delivery devices is constantly changing; therefore, it has proven extremely difficult to study the long-term effects on the heart caused by electronic cigarettes but will be important to understand given their rising popularity. The arrhythmic effects of electronic cigarettes appear similar to traditional cigarettes as well; however, a comprehensive review has not been compiled and is the focus of this article.

BACKGROUND: Stroke, as a common cerebrovascular disease, has a high mortality and disability rate. Although many studies have reported that using e-cigarettes was associated with occurrence of stroke, some studies have concluded that e-cigarettes may help smokers stop using combustible cigarettes and reduce the risk of stroke. Therefore, we aimed to validate the hypothesis that e-cigarette use might be an independent risk factor for stroke occurrence by performing a systematic review and meta-analysis of clinical epidemiology studies.
METHODS: The pooled effect was calculated by the random effects model. I2 was used to test for heterogeneity. Sensitivity analysis was performed to evaluate the stability of the overall results. Funnel plot symmetry or Egger\'s regression was used to evaluate publication bias. All p values were two-sided with significance level at 0.05.
RESULTS: Six cross-sectional studies with high quality were finally included in the meta-analysis, which included a total of 1134896 participants. Analysis with random effects model showed that the total pooled odds ratio (OR) of stroke occurrence in e-cigarette users was 1.25 (95% CI: 1.01-1.55) (I2=96.6%, p<0.001). A stable result was revealed by sensitivity analysis. There was no publication bias. Due to high heterogeneity, we performed subgroup analysis. Compared to neither e-cigarette nor combustible cigarette users, pooled OR of stroke occurrence in e-cigarette only users was 1.13 (95% CI: 0.99-1.29) (I2=45.9%, p=0.116). Compared to combustible cigarette only users, pooled OR of stroke occurrence in both of e-cigarette and combustible cigarette users was 1.39 (95% CI: 1.19-1.64) (I2=5.6%, p=0.303). In addition, pooled OR in currently e-cigarette only users who were formerly combustible cigarette only users was 1.59 (95% CI: 1.22-2.07) (I2=0.0%, p=0.989).
CONCLUSIONS: The role of e-cigarette use in the development of stroke is inconclusive, due to the strong effect of prior tobacco use as a risk factor for stroke in the included studies.

BACKGROUND: The purpose of this systematic review study was to determine the national, regional, and global prevalence of electronic cigarettes (e-cigarettes) vaping.
METHODS: The articles were searched in July 2020 without a time limit in Web of Science (ISI), Scopus, PubMed, and Ovid-MEDLINE. At first, the titles and abstracts of the articles were reviewed, and if they were appropriate, they entered the second stage of screening. In the second stage, the whole articles were reviewed and articles that met the inclusion criteria were selected. In this study, search, selection of studies, qualitative evaluation, and data extraction were performed by two authors independently, and any disagreement between the two authors was reviewed and corrected by a third author.
RESULTS: In this study, the lifetime and current prevalence of e-cigarettes vaping globally were 23% and 11%, respectively. Lifetime and current prevalence of e-cigarettes vaping in women were 16% and 8%, respectively. Also, lifetime and current prevalence of e-cigarettes vaping in men were 22% and 12%, respectively. In this study, the current prevalence of e-cigarettes vaping in who had lifetime smoked conventional cigarette was 39%, and in current smokers was 43%. The lifetime prevalence of e-cigarettes vaping in the Continents of America, Europe, Asia, and Oceania were 24%, 26%, 16%, and 25%, respectively. The current prevalence of e-cigarettes vaping in the Continents of America, Europe, Asia, and Oceania were 10%, 14%, 11%, and 6%, respectively.
CONCLUSIONS: Based on the results of this study, it can be concluded that the popularity of e-cigarettes is increasing globally. Therefore, it is necessary for countries to have more control over the consumption and distribution of e-cigarettes, as well as to formulate the laws prohibiting about the e-cigarettes vaping in public places. There is also a need to design and conduct information campaigns to increase community awareness about e-cigarettes vaping.

Electronic cigarettes (ECs) are purported to be tobacco harm-reduction products whose degree of harm has been highly debated. EC use is considered less hazardous than smoking but is not expected to be harmless. Following the banning of e-liquid flavors in countries such as the US, Finland, Ukraine, and Hungary, there are growing concerns regarding the safety profile of e-liquid flavors used in ECs. While these are employed extensively in the food industry and are generally regarded as safe (GRAS) when ingested, GRAS status after inhalation is unclear. The aim of this review was to assess evidence from 38 reports on the adverse effects of flavored e-liquids on the respiratory system in both in vitro and in vivo studies published between 2006 and 2021. Data collected demonstrated greater detrimental effects in vitro with cinnamon (9 articles), strawberry (5 articles), and menthol (10 articles), flavors than other flavors. The most reported effects among these investigations were perturbations of pro-inflammatory biomarkers and enhanced cytotoxicity. There is sufficient evidence to support the toxicological impacts of diacetyl- and cinnamaldehyde-containing e-liquids following human inhalation; however, safety profiles on other flavors are elusive. The latter may result from inconsistencies between experimental approaches and uncertainties due to the contributions from other e-liquid constituents. Further, the relevance of the concentration ranges to human exposure levels is uncertain. Evidence indicates that an adequately controlled and consistent, systematic toxicological investigation of a broad spectrum of e-liquid flavors may be required at biologically relevant concentrations to better inform public health authorities on the risk assessment following exposure to EC flavor ingredients.