Estimation of Health Risks Caused by Metals Contained in E-Cigarette Aerosol through Passive Vaping.

It is expected that secondary exposure to e-cigarette aerosol (passive vaping) will soon become an issue of public health. Passive vaping inhales e-cigarette aerosol containing similar harmful substances as active vaping. However, parallel studies on passive vaping are minimal. Therefore, there is a need for passive vaping-related health risk studies to assess the impact of vaping on public health. This research conducted a series of experiments in a room using a puffing machine and the Mobile Aerosol Lung Deposition Apparatus (MALDA) to study e-cigarette aerosol respiratory deposition through passive vaping. The experimental data acquired were applied to estimate the deposited mass and health risks caused by toxic metals contained in e-cigarette aerosol. Five popular e-cigarette products were used in this study to generate e-cigarette aerosol for deposition experiments. In addition, size-segregated e-cigarette aerosol samples were collected, and metal compositions in the e-cigarette aerosol were analyzed. Results obtained showed that estimated non-cancer risks were all acceptable, with hazard quotient and hazard index all less than 1.0. The calculated cancer risks were also found acceptable, with lifetime excess cancer risk generally less than 1E-6. Therefore, the e-cigarettes tested and the passive vaping exposure scenarios studied do not seem to induce any potential for metal-related respiratory health effects.

An Exploratory Study on Strategies Adopted by Parents Who Use E-Cigarettes to Negotiate Risk Perceptions of Their Children's Secondhand Exposure and Parental Role Modeling.

Existing health messages mainly targeted youth susceptible to vaping or parents who do not have much knowledge about e-cigarettes. This study makes a unique contribution by conducting the first in-depth investigation of e-cigarette-using parents' risk perceptions and parental role modeling and how these two factors affect their vaping behaviors at home or implementation of any strategies to reduce their children's risk. Fifteen parents who used e-cigarettes participated in a semi-structured interview. Interview transcripts were coded and analyzed through a deductive approach of thematic analysis. This study demonstrates the need to develop and disseminate future health messages for e-cigarette-using parents who may have low-risk perceptions of secondhand exposure or who have adopted ineffective strategies to reduce their children's exposure. This study also identifies some possible targets for future intervention efforts through these parents including increasing their knowledge about the health risk of secondhand exposure to e-cigarettes, emphasizing the caregiver role, and effective communications with children about the consequences of vaping.

Estimation of the dose of electronic cigarette chemicals deposited in human airways through passive vaping.

BACKGROUND: Existing studies on the health effects of e-cigarettes focused on e-cigarette users themselves. To study the corresponding effects on passive vapers, it is crucial to quantify e-cigarette chemicals deposited in their airways. OBJECTIVE: This study proposed an innovative approach to estimate the deposited dose of e-cigarette chemicals in the passive vapers' airways. The effect of the distance between active and passive vapers on the deposited dose was also examined. METHODS: The chemical constituent analysis was conducted to detect Nicotine and flavoring agents in e-cigarette aerosol. The Mobile Aerosol Lung Deposition Apparatus (MALDA) was employed to conduct aerosol respiratory deposition experiments in real-life settings to generate real-time data. RESULTS: For e-cigarette aerosol in the ultrafine particle regime, the deposited doses in the alveolar region were on average 3.2 times higher than those in the head-to-TB airways, and the deposited dose in the passive vaper's airways increased when being closer to the active vaper. SIGNIFICANCE: With prolonged exposure and close proximity to active vapers, passive vapers may be at risk for potential health effects of harmful e-cigarette chemicals. The methodology developed in this study has laid the groundwork for future research on exposure assessment and health risk analysis for passive vaping.

Social media and E-cigarette use among US youth: Longitudinal evidence on the role of online advertisement exposure and risk perception.

OBJECTIVES: Previous studies revealed a link between social media use and e-cigarette use among U.S. youth, but less is known about the mechanisms through which they interconnect. This study examined how social media and e-cigarette use are connected through online advertisement exposure and risk perception of e-cigarettes among U.S. youth. METHODS: Youth aged 12-17 from the Public Assessment of Tobacco and Health (PATH) Study Waves 2-4 (2014-2018) were included (N = 6,208). This study integrated the incidental exposure framework and the risk perception framework to guide study conceptualization and variable selection. Generalized structural equation modeling was performed to investigate the sequential mediation relationship between social media and e-cigarette use through online e-cigarette advertisement exposure and risk perception of e-cigarette use. RESULTS: Youth respondents with more social media use were more likely to be exposed to e-cigarette advertisement at Wave 2 (OR = 1.13, p < 0.001), which led to lower e-cigarette risk perception at Wave 3 (ß = -0.07, p < 0.001). Higher e-cigarette risk perception at Wave 3 resulted in lower likelihood of e-cigarette use at Wave 4 (OR = 0.57, p < 0.001). High social media use at Wave 2 was directly associated with high likelihood of e-cigarette use at Wave 4 (OR = 1.11, p < 0.001). CONCLUSIONS: The results indicate that social media use is associated with increased e-cigarette use through online e-cigarette advertisement exposure and subsequently decreased e-cigarette risk perception among U.S. youth. Our findings underscore the importance of regulating online e-cigarette advertisement, with the emphasis of avoiding information that could twist youth's risk perception of e-cigarettes, which may in turn curtail youth e-cigarette use.

Validating E-Cigarette Dependence Scales Based on Dynamic Patterns of Vaping Behaviors.

INTRODUCTION: Existing e-cigarette dependence scales are mainly validated based on retrospective overall consumption or perception. Further, given that the majority of adult e-cigarette users also use combustible cigarettes, it is important to determine whether e-cigarette dependence scales capture the product-specific dependence. This study fills in the current knowledge gaps by validating e-cigarette dependence scales using novel indices of dynamic patterns of e-cigarette use behaviors and examining the association between dynamic patterns of smoking and e-cigarette dependence among dual users. METHODS: Secondary analysis was conducted on the 2-week ecological momentary assessment data from 116 dual users. The Smoothly Clipped Absolute Deviation penalty (SCAD) was adopted to select important indices for dynamic patterns of consumption or craving and estimate their associations with e-cigarette dependence scales. RESULTS: The fitted linear regression models support the hypothesis that higher e-cigarette dependence is associated with higher levels of e-cigarette consumption and craving as well as lower instability of e-cigarette consumption. Controlling for dynamic patterns of vaping, dual users with lower e-cigarette dependence tend to report higher day-to-day dramatic changes in combustible cigarette consumption but not higher average levels of smoking. CONCLUSIONS: We found that more stable use patterns are related to higher levels of dependence, which has been demonstrated in combustible cigarettes and we have now illustrated in e-cigarettes. Furthermore, the e-cigarette dependence scales may capture the product-specific average consumption but not product-specific instability of consumption. IMPLICATIONS: This study provides empirical support for three e-cigarette dependence measures: PS-ECDI, e-FTCD, and e-WISDM, based on dynamic patterns of e-cigarette consumption and craving revealed by EMA data that have great ecological validity. This is the first study that introduces novel indices of dynamic patterns and demonstrates their potential applications in vaping research.

The association between union membership and perceptions of safety climate among US adult workers.

OBJECTIVES: An individual's perceptions of their workplace safety climate can influence their health and safety outcomes in the workplace. Even though union membership has been declining in the US, union members still comprise 10% of the working population and have higher-than-industry average non-fatal illness and injury rates. Due to limited research focused in this area, this study examined whether union membership was associated with worker perceptions of safety climate. METHODS: This was a secondary data analysis study utilizing data from the Quality Work Life module from the General Social Survey centered on US workers aged 18 and above. Propensity-score matching was implemented to reduce potential selection bias between unionized and non-unionized workers. Linear regression explored the association between union membership and perceptions of safety climate, controlling for age, sex, education, industry, resource adequacy, supervisor support, co-worker support, and workload. RESULTS: For perceived safety climate (on a 0-16 scale, the higher the more positive), those in union had a lower mean of perceived safety climate (12.44) compared to those not in a union (13.20). Based on the regression results, those who were in a union reported more negative perceptions of their workplace safety climate in a 12-month period (ß = -0.61, p < .001). CONCLUSIONS: By demonstrating a commitment to proactive injury prevention and bolstering the business's overall safety performance indicators, businesses who are open to collaborations with unions may see some long-term benefits (e.g. return on investment, increased job satisfaction) and enhance union workers' perceptions of safety climate.

The association between short-term emotion dynamics and cigarette dependence: A comprehensive examination of dynamic measures.

BACKGROUND: The association between short-term emotion dynamics and long-term psychopathology has been well established in the psychology literature. Yet, dynamic measures for inertia and instability of negative and positive affect have not been studied in terms of their association with cigarette dependence. This study builds an important bridge between the psychology and substance use literatures by introducing these novel measures and conducting a comprehensive examination of such association with intervention implications. METHODS: This study conducted secondary analysis on the data from a community sample of 136 dual users (e-cigarette + cigarette) and 101 exclusive smokers who completed both the two-week ecological momentary assessment (EMA) and cigarette dependence assessments in a recent study. RESULTS: Among dual users, a higher average level of negative affect, lower inertia of negative affect (i.e., less sustained negative affect), and higher instability of positive affect (i.e., greater magnitude of changes in positive affect) were associated with higher cigarette dependence. The patterns of associations among exclusive smokers were, however, different. Higher inertia of negative affect, lower instability of positive affect, and higher variability of negative affect were associated with higher dependence. CONCLUSIONS: The results illustrate the importance of examining not only negative affect but also positive affect in order to fully understand the association between emotion dynamics and cigarette dependence. The different patterns of association between emotion dynamics and cigarette dependence across the two groups of cigarette users also call for future research that is designed to compare cigarettes and e-cigarettes in terms of their effects on emotion regulation.

Deposition of E-cigarette aerosol in human airways through passive vaping.

Secondary exposure to e-cigarette aerosol (passive vaping) will soon become a pressing public health issue in the world. Yet, the current knowledge about respiratory depositions of e-cigarette aerosol through passive vaping in human airways is limited due to critical weaknesses of traditional experimental methods. To fill in this important knowledge gap, this study proposed a special approach involving an upgraded Mobile Aerosol Lung Deposition Apparatus (MALDA) that consists of a set of human airway replicas including a head airway, tracheobronchial airways down to the 11th lung generation, and a representative alveolar section. In addition to the comprehensive coverage of human airways, the MALDA is easily transportable for providing efficient estimations of aerosol respiratory deposition. In this study, the MALDA was first evaluated in the laboratory and then applied to estimate the respiratory deposition associated with passive vaping in an indoor real-life setting. The results showed that the respiratory deposition data aligned closely with the conventional respiratory deposition curves not only in the head-to-TB region but also in the alveolar region. The strengths of MALDA demonstrate great promise for a wide variety of applications in real-life settings that could provide crucial information for future public health and indoor air quality studies.

State Medical Marijuana Laws and Associated Marijuana Use, Attitudes, and Perceived Social Norms among Adolescents in the U.S.

Statewide medical marijuana laws (MMLs) in the U.S. may be associated with adolescent marijuana use behavior, attitudes toward marijuana use, and social norms. This study used data from the National Study on Drug Use and Health (2013-2016) to examine the associations of state MML with marijuana use, use frequency, and attitudes and perceived peer and parental social norms toward using marijuana. Propensity-score matching was used to reduce selection bias between states with and without MML (matched N = 50,000). Results showed that adolescents residing in states with MML had higher odds of using marijuana in the past month and past year (OR = 1.45 and 1.49; ps < .001), higher marijuana use frequencies in the past month (ß = 0.12, p < .001), relatively more neutral attitudes toward marijuana use (ß = - 0.06, p < .001), and weaker perception of peer and parental disapproval of marijuana use (ß = - 0.04 and -0.02, ps < .001). Our findings suggested that for the states that have implemented MML, special efforts should be strengthened to prevent and reduce adolescent marijuana use. For the states that have not yet implemented MML, the associations between MML and adolescent marijuana use attitudes and perceived norms should be taken into account when legislating medical marijuana and designing prevention and intervention efforts.

Is E-cigarette use a gateway to marijuana use? Longitudinal examinations of initiation, reinitiation, and persistence of e-cigarette and marijuana use.

BACKGROUND: Concerns have been raised regarding e-cigarette use as a potential stepping-stone to marijuana use. Based on Kandel's gateway hypothesis, this study investigated if e-cigarette use could lead to marijuana use by testing two hypotheses with a longitudinal national U.S. adult sample, including (1) primary hypothesis: e-cigarette use is a gateway to marijuana use; and (2) falsification hypothesis: marijuana use is not a gateway to e-cigarette use. METHODS: Adults were extracted from the Population Assessment of Tobacco and Health Study Waves 1-3 (2013-2016). For primary hypotheses, based on baseline e-cigarette use statuses, three study groups were defined, and three logistic regressions were conducted to examine associations between baseline e-cigarette use and follow-up marijuana use initiation, reinitiation, and persistence, respectively. Similarly, for falsification hypotheses, three additional study groups were defined, and three logistic regressions were conducted to examine associations between baseline marijuana use and follow-up e-cigarette use behaviors. RESULTS: Baseline e-cigarette use was associated with marijuana use initiation and reinitiation (ORs = 2.08, 1.37, respectively, both ps < .05) but not persistence at follow-up. Additionally, baseline marijuana use was associated with only e-cigarette use initiation (OR = 2.23, p < .01) but not reinitiation or persistence at follow-up. CONCLUSIONS: Findings partially support the gateway hypothesis that e-cigarette use could be a steppingstone to marijuana use reinitiation among the U.S. adults. The mechanisms and behavioral characteristics, such as etiological and psychosocial factors, that may pertain to the progression from e-cigarette use to reinitiation of other substance use should be further investigated to inform effective behavioral, educational, and policy interventions.

Comparing American college and noncollege young adults on e-cigarette use patterns including polysubstance use and reasons for using e-cigarettes.

Objective: Existing literature on young adults' e-cigarette and polysubstance use focused on college students. This study examined the differences between college and noncollege groups on prevalence and patterns of e-cigarette and other substance use using data from a national survey. Participants: Adults aged 18-24 from the 2013-2014 Population Assessment of Tobacco and Health Study (n = 6,608). Methods: Independent sample t-tests and Chi-square tests were conducted to examine group differences. Results: Noncollege young adults had higher prevalence of cigarette, e-cigarette, and marijuana use; college students had higher prevalence of alcohol use. Among current e-cigarette users, college students had higher prevalence of polysubstance use of alcohol and marijuana. College students used e-cigarettes for socializing purposes more. Conclusions: Differences in prevalence and patterns of e-cigarette and other substance use between college and noncollege groups exist. Future interventions should target the social context of college life and reach out to noncollege young adults in workplaces.

Measuring characteristics of e-cigarette consumption among college students.

Objective: E-cigarette use among college students has increased drastically in recent years. This study aims to inform development of a comprehensive measure of e-cigarette consumption for this population. Participants and Methods: This mixed-method study collected both quantitative and qualitative data from a sample of 43 experienced e-cigarette users from two college campuses, using a self-reported questionnaire and a semi-structured interview, in March-September of 2017. Results: College student users found some of the consumption questions in national surveys difficult to answer. Switching nicotine levels, mixing flavors, co-using with alcohol and marijuana, using with others who were vaping or drinking, and vaping in a car or indoor space were all common. The participants defined "regular user" based on ownership of a device rather than on quantity/frequency. Conclusions: A comprehensive e-cigarette consumption measure should cover the complex characteristics that are potentially associated with negative health consequences such as flavorings, co-use and social contexts.

Medical marijuana legalization and associated illicit drug use and prescription medication misuse among adolescents in the U.S.

BACKGROUND: Use of illicit drugs and misuse of prescription medications among U.S. adolescents have been major public health issues. As over half of the states have implemented medical marijuana laws (MMLs), it is unclear if MML implementation is associated with use of illicit drugs and misuse of prescription medications among adolescents. METHODS: This study used data from the 2013-2014 National Survey of Drug Use and Health and included adolescents aged 12-18 with a total of 26,826 participants after the propensity-score matching used to reduce selection bias between states that had and had not implemented MML. Seven logistic regressions were conducted to examine MML implementation and associated use of illicit drugs (including cocaine/crack, heroin, hallucinogens, and inhalants) and misuse of prescription medications (including pain relievers, tranquilizers/sedatives, and stimulants), controlling for sociodemographics and use of cigarettes, alcohol, and marijuana. RESULTS: Adolescents residing in the states that had legalized medical marijuana were more likely to use cocaine/crack and heroin in the past 12 months (OR = 1.63, 2.61, respectively; both ps < 0.05). However, MML implementation was not associated with the likelihood of using other illicit drugs or misusing prescription medications. CONCLUSIONS: The study findings suggest that for the states that have implemented MML, policy and educational interventions should as well be implemented to prevent not only marijuana use but also use of other harder drugs such as cocaine/crack and heroin among adolescents. States that have yet implemented MML should consider the possible associations between MML implementation and use of other illicit drugs when legislating MML.

Rapamycin synergizes cisplatin sensitivity in basal-like breast cancer cells through up-regulation of p73.

Recent gene expression profiling studies have identified five breast cancer subtypes, of which the basal-like subtype is the most aggressive. Basal-like breast cancer poses serious clinical challenges as there are currently no targeted therapies available to treat it. Although there is increasing evidence that these tumors possess specific sensitivity to cisplatin, its success is often compromised due to its dose-limiting nephrotoxicity and the development of drug resistance. To overcome this limitation, our goal was to maximize the benefits associated with cisplatin therapy through drug combination strategies. Using a validated kinase inhibitor library, we showed that inhibition of the mTOR, TGFßRI, NFκB, PI3K/AKT, and MAPK pathways sensitized basal-like MDA-MB-468 cells to cisplatin treatment. Further analysis demonstrated that the combination of the mTOR inhibitor rapamycin and cisplatin generated significant drug synergism in basal-like MDA-MB-468, MDA-MB-231, and HCC1937 cells but not in luminal-like T47D or MCF-7 cells. We further showed that the synergistic effect of rapamycin plus cisplatin on basal-like breast cancer cells was mediated through the induction of p73. Depletion of endogenous p73 in basal-like cells abolished these synergistic effects. In conclusion, combination therapy with mTOR inhibitors and cisplatin may be a useful therapeutic strategy in the treatment of basal-like breast cancers.