BACKGROUND: Electronic cigarettes (e-cigarettes) are often advertised as a safer alternative to traditional smoking. However, recent data suggest they may not be as safe as previously believed. This study aims to evaluate the genotoxicity and mutagenicity of e-cigarette liquids.
METHODS: We randomly selected eight varieties of e-cigarette liquids from the local market in Jeddah, Saudi Arabia. We evaluated their genotoxicity using the Genotoxicity SOS-Chromo Test™ Kit. In this investigation, a rat liver S9 fraction was utilized to emulate liver metabolic function to measure any chemical substance\'s mutagenic potential. The SOS-Chromo Test was performed by recording the β-galactosidase and alkaline phosphatase activity with and without the metabolic activation enzyme (S-9).
RESULTS: All samples, except for the first two dilutions of sample 2, were nongenotoxic in the absence of the S9 activation enzyme, according to the genotoxicity analysis. However, when tested in the presence of the S9 enzyme, samples 2, 4, and 7 exhibited mutagenic activity at varying concentrations.
CONCLUSIONS: Contrary to common belief, e-cigarettes are not safe. The present investigation confirms the presence of both toxicants and carcinogens in some e-cigarette liquids. This exposure could increase users\' risk of various health complications.

BACKGROUND: Electronic nicotine delivery systems (ENDS) offer a promising approach to tobacco harm reduction, but many people use both ENDS and combustible cigarettes (\"dual use\"), which undermines potential risk reduction. To explore the role of ENDS nicotine delivery in promoting switching to ENDS, we conducted a study in which people who smoked cigarettes were offered an ENDS that had previously been shown to replicate the rapid nicotine pharmacokinetics of combustible cigarettes (BIDI® Stick).
METHODS: Twenty-five cigarette smoking adults, not seeking smoking cessation treatment, but open to using ENDS as a cigarette substitute, were provided with a 12-week supply of BIDI® Stick in tobacco or menthol flavors, during a study that included seven biweekly sessions and a 6-month follow-up. Daily diaries assessed ENDS and cigarette use, and exhaled carbon monoxide (eCO) served as an objective marker of smoke intake. Subjective ratings were collected to assess the rewarding properties of ENDS and combustible cigarettes, and indices of nicotine dependence.
RESULTS: Over 12 weeks, ENDS use increased to an average of 15.8 occasions per day (SD = 20.2) and self-reported cigarette consumption decreased by 82% from 16.7 cigarettes/day (SD = 6.0) at baseline to 3.0 cigarettes/day (SD = 4.1) at week 12. The eCO level decreased by 27% from an average of 20.0 ppm (SD = 9.8) at baseline to 14.5 ppm (SD = 9.9) at week 12. Four of 25 participants completely switched to ENDS and were smoking abstinent during weeks 9-12. At 6 months one participant was confirmed to be abstinent. Ratings of subjective reward for the ENDS were very similar to those of participants\' usual brands of cigarettes. Dependence level was lower for the ENDS than for combustible cigarettes.
CONCLUSIONS: In this study, the ENDS effectively replicated the subjective rewarding effects of participants\' usual brands of cigarettes and led to a substantial reduction in reported cigarettes/day. Exhaled CO showed less of a decrease, possibly due to compensatory smoking behavior and/or the timing of eCO measurements that might not have reflected smoke intake throughout the day. The relatively low rate of sustained smoking abstinence at 6 months suggests that additional approaches continue to be needed for achieving higher rates of complete switching.
BACKGROUND: ClinicalTrials.gov identifier NCT05855343.

UNASSIGNED: E-cigarettes are the most-used nicotine product among adolescents, but limited psychometrically-sound, e-cigarette-relevant measures exist for adolescents. We examined psychometric properties of the Self-Report Habit Index (SRHI) for assessing adolescents\' habitual e-cigarette use.
UNASSIGNED: During Fall 2022, 4855 students from eight Connecticut high schools completed an anonymous survey. The analytic sample comprised 491 students who reported past-month e-cigarette use and completed the SRHI (Age M=15.94, SD=1.24 years, 56 % female, 37.1 % Hispanic, 57.6 % White). We examined the SRHI\'s latent factor structure; internal reliability; measurement invariance and between-groups differences (e.g., nicotine vs. nicotine-free vaping); and associations with total e-cigarette flavors used in the past month, past-30-day vaping frequency, and e-cigarette dependence.
UNASSIGNED: The SRHI\'s 6-item, 1-factor structure was confirmed. Internal reliability was excellent. The SRHI was scalar invariant for all subgroups tested. Nicotine (vs. nicotine-free) and daily (vs. non-daily) e-cigarette use were associated with greater habitual e-cigarette use behavior. In adjusted models, habitual e-cigarette use was associated with using more e-cigarette flavors, vaping more frequently, and greater e-cigarette dependence. Habitual e-cigarette use incrementally accounted for variance in past-month flavors used and vaping frequency beyond dependence.
UNASSIGNED: The SRHI evidenced solid psychometric properties for assessing habitual e-cigarette use behavior among high school students. Relationships between habitual use and frequency of use, e-cigarette flavors, and dependence might be expected as these constructs are associated with the three characterizing features of habitual behaviors: frequent repetition, cue-driven elicitation, and automaticity. Future prospective research can clarify the temporal ordering of habitual e-cigarette use and dependence in adolescents.

BACKGROUND: Electronic cigarettes (ECs) have been promoted as alternatives to traditional cigarettes.
OBJECTIVE: To investigate ECs\' effects on respiratory system, especially in patients with respiratory diseases.
METHODS: We randomly selected 25 smokers with stable moderate asthma and matched them with 25 healthy smokers. All were subjucted to pulmonary function tests (PFTs), impulse oscillometry (IOS), fraction exhaled Nitric Oxide (FeNO), exhaled breathe condensate (EBC) and biomarker measurements before and after vaping one nicotine-containing EC.
RESULTS: The increase in FeNO 30 minutes after EC, reflecting airway inflammation, significantly correlated with increase of residual volume (RV), total lung capacity, respiratory impedance at 5 Hz (Z5Hz) and respiratory resistance at 5 and 20 Hz (R5Hz and R20Hz). No significant correlations were found between EBC biomarkers\' changes and respiratory mechanics.
CONCLUSIONS: This is the first study demonstrating that the changes in airway inflammation caused by EC have direct effects in respiratory mechanics of asthmatic patients.

The emerging concern about chemicals in electronic cigarettes, even those without nicotine, demands the development of advanced criteria for their exposure and risk assessment. This study aims to highlight the sensitivity of lung nuclear receptors (NRs) to electronic cigarette e-liquids, independent of nicotine presence, and the influence of the sex variable on these effects. Adult male and female C57BL/6J mice were exposed to electronic cigarettes with 0%, 3%, and 6% nicotine daily (70 mL, 3.3 s, 1 puff per min/30 min) for 14 days, using the inExpose full body chamber (SCIREQ). Following exposure, lung tissues were harvested, and RNA extracted. The expression of 84 NRs was determined using the RT2 profiler mRNA array (Qiagen). Results exhibit a high sensitivity to e-liquid exposure irrespective of the presence of nicotine, with differential expression of NRs, including one (females) and twenty-four (males) in 0% nicotine groups compared to non-exposed control mice. However, nicotine-dependent results were also significant with seven NRs (females), fifty-three NRs (males) in 3% and twenty-three NRs (female) twenty-nine NRs (male) in 6% nicotine groups, compared to 0% nicotine mice. Sex-specific changes were significant, but sex-related differences were not observed. The study provides a strong rationale for further investigation.

OBJECTIVE: The primary objective of this in vitro experiment was an assessment of proliferative capacity, metabolic activity, and potential cellular detriment of human periodontal ligament cells (hPDL) exposed to cigarette smoke (CS), electronic cigarette vapor (eCV), and heated tobacco product aerosol (HTP), or air (control).
METHODS: Using a CAD/CAM-designed exposition chamber, hPDL were exposed to CS, eCV, HTP, or air (control) based on the Health Canada Intense Smoking Regime. Cell proliferation, metabolic activity, and cellular detriment were assessed at various time points.
RESULTS: Compared to the control, hPDL exposed to CS exhibited significantly decreased cell numbers at all time points. HTP exposure led to reduced cell numbers 48 h and 72 h post-exposure, while eCV-exposed cells showed no significant decrease. The metabolic activity of eCV-treated hPDL was slightly reduced at 7 h but recovered at 24 h and 48 h. In contrast, CS-treated cells exhibited significantly decreased metabolic activity at 24 h and 48 h, and HTP-exposed cells showed a significant decrease after 48 h. Flow cytometry indicated both apoptotic and necrotic cell death following CS exposure, with necrotic cell death being more pronounced.
CONCLUSIONS: eCV and HTP demonstrated comparatively reduced detrimental effects on hPDL compared to CS.
CONCLUSIONS: The findings suggest that conventional cigarette smoke poses a substantial risk to periodontal health by significantly impairing cell proliferation and metabolic activity. However, alternatives such as eCV and HTP may offer a comparatively reduced risk.

BACKGROUND: Perceptions, personal perspectives, and public awareness of e-cigarette information have a significant impact on e-cigarette smoking behavior, and provide comprehensive information that can help reduce interest in e-cigarette smoking and reduce the number of new smokers. This study aimed to investigate the perceptions towards e-cigarettes related to e-cigarette use and how that information related to people\'s use of them.
METHODS: The data for this cross-sectional study were collected via an online questionnaire. Thai nationals who were aged ≥18 years provided data between June 2021 and January 2022. Multivariable logistic regression and the chi-squared test were used to analyze the data.
RESULTS: There were 340 respondents, 76 e-cigarette users, and 264 non-e-cigarette users. Most of the perceptions of information that differed statistically significantly between e-cigarette users and non-e-cigarette users included information on regulations, products, health effects, and the effectiveness of smoking cessation. The association between factors and e-cigarette smoking behavior revealed that the perception of the product information and male gender were associated with e-cigarette smoking behavior (AOR=13.59; 95% CI: 2.35-78.60, and AOR=5.19; 95% CI: 2.87-9.40, respectively).
CONCLUSIONS: The perception of e-cigarette product information and male gender were associated with e-cigarette smoking behavior.

Electronic cigarettes (e-cigarettes) and vaping have gained popularity in the last two to five years as an alternative way of consuming nicotine, as well as tetrahydrocannabinol (THC), particularly in the younger population. Vaping/e-cigarettes heat nicotine/THC and other chemical components to create the vapor to be inhaled, which increases the risk of mucosal infection and esophagitis. Although tobacco smoking has been extensively studied and known to affect the oral cavity and esophagus, the effect of vaping is yet to be well-studied. We report a case of odynophagia secondary to esophageal candidiasis, herpes simplex virus (HSV) esophagitis, and reflux esophagitis associated with vaping.

UNASSIGNED: Smoking is known to be a major risk factor for several diseases. Recently, electronic cigarettes have been introduced to the market; however, their effect on oral health has not been well studied yet. We aim to compare the effect of different types of smoking on oral health and to evaluate cytomorphological changes in oral mucosa among different types of smokers.
UNASSIGNED: A total of 112 participants were recruited, conventional cigarette smokers (n = 28), electronic cigarettes smokers (n = 26), hookah smokers (n = 29) and non-smokers (n = 29). Oral examination, brush cytology and salivary flow test were performed. Cytological smears were stained and examined for cytomorphological changes. Oral symptoms, type, and frequency of smoking were obtained through questionnaires. SPSS program was used for statistical analysis.
UNASSIGNED: Most of the oral symptoms reported in this study were among conventional and electronic cigarettes smokers. While hookah smokers reported the least oral symptoms. Increase in DMFT and gingival index were observed among all smokers, mainly among conventional cigarettes smokers. Conventional cigarette and hookah smokers were found to have the most significant cellular changes. Electronic cigarette smokers had certain cellular changes as well.
UNASSIGNED: All types of smoking adversely affect oral health and can induce cellular changes in the oral mucosa.

The use of electronic cigarettes (ECs) is a major problem globally. Susceptibility and curiosity are important factors that develop prior to the onset of substance use, such as ECs, and are therefore considered as predictors. Both factors are used to obtain an extended index of susceptibility (ESIe-c), which allows the identification of adolescents who are at risk of starting to use these devices. The aim of this study was to determine the prevalence of EC consumption and to assess the association of possible predictors with susceptibility to use and experimentation with ECs among adolescents. A cross-sectional study was carried out in 377 adolescents (53.0% female). Participants were compared according to their experimentation with ECs. A total of 45.9% had already used electronic cigarettes, and 20.8% were current users. Among those who had not tried electronic cigarettes, 43.3% had a medium-high susceptibility to EC initiation. Consumption among close friends, receiving offers of consumption and alcohol consumption were associated with initiation. There was an inverse association between a medium susceptibility index electronic cigarette score and the consumption of cigarettes and positive affect; on the other hand, the lack of premeditation was associated with a higher susceptibility index score. Intrapersonal factors and social factors seem to influence the ESIe-c and onset of EC use, respectively. The main conclusion in this study is that susceptibility is influenced by intrapersonal factors such as affectivity and impulsivity through the lack of premeditation, and by social factors such as EC consumption by best friends.