Eric K. Soule

Electronic cigarettes: what are they and what do they do?

Electronic cigarettes (ECIGs) use electricity to power a heating element that aerosolizes a liquid containing solvents, flavorants, and the dependence‐producing drug nicotine for user inhalation. ECIGs have evolved rapidly in the past 8 years, and the changes in product design and liquid constituents affect the resulting toxicant yield in the aerosol and delivery to the user. This rapid evolution has been accompanied by dramatic increases in ECIG use prevalence in many countries among adults and, especially, adolescents in the United States. The increased prevalence of ECIGs that deliver nicotine and other toxicants to users’ lungs drives a rapidly growing research effort. This review highlights the most recent information regarding the design of ECIGs and their liquid and aerosol constituents, the epidemiology of ECIG use among adolescents and adults (including correlates of ECIG use), and preclinical and clinical research regarding ECIG effects. The current literature suggests a strong rationale for an empirical regulatory approach toward ECIGs that balances any potential ECIG‐mediated decreases in health risks for smokers who use them as substitutes for tobacco cigarettes against any increased risks for nonsmokers who may be attracted to them.

Electronic cigarette use and indoor air quality in a natural setting

Introduction Secondhand smoke (SHS) from combustible cigarettes causes numerous diseases. Policies have been developed to prevent SHS exposure from indoor cigarette use to reduce health risks to non-smokers. However, fewer policies have been implemented to deter electronic cigarette (ECIG) use indoors, and limited research has examined the impact of secondhand exposure to ECIG aerosol. Methods Indoor air quality was measured at a 2-day ECIG event held in a large room at a hotel. Fine particulate matter (PM) was measured using 2 devices that measured concentrations of PM 2.5 μm aerodynamic diameter or smaller (PM2.5). Measurements were taken before the event, over 2 days when the event was ongoing, and the day after the event. PM2.5 measurements were also taken from the restaurant at the hotel hosting the event and a restaurant at a nearby hotel. Results During 6 time points when the event was ongoing, between 59 and 86 active ECIG users were present in the event room (room volume=4023 m3). While the event was ongoing, median PM2.5 concentrations in the event room increased from a baseline of 1.92–3.20 μg/m3 to concentrations that ranged from 311.68 μg/m3 (IQR 253.44–411.84 μg/m3) to 818.88 μg/m3 (IQR 760.64–975.04 μg/m3). Conclusions PM2.5 concentrations observed at the ECIG event were higher than concentrations reported previously in hookah cafés and bars that allow cigarette smoking. This study indicates that indoor ECIG use exposes non-users to secondhand ECIG aerosol. Regulatory bodies should consider establishing policies that prohibit ECIG use anywhere combustible cigarette use is prohibited.

Waterpipe tobacco smoking: A new smoking epidemic among the young?

Waterpipe (hookah, narghile) tobacco smoking (WTS) is becoming prevalent worldwide and is one of the most popular forms of tobacco use among youth. WTS prevalence has increased dramatically among youth in the USA within the past decade. Misperceived as less harmful than cigarette smoking, WTS is associated with many of the same chronic health effects such as lung cancer, chronic obstructive pulmonary disease, cardiovascular disease, bronchitis, and asthma. Much of this risk is due to the fact that a single WTS session exposes users to large volumes of smoke that contain toxic chemicals such as carbon monoxide, cancer-causing polycyclic aromatic hydrocarbons, and volatile aldehydes. Unlike cigarette smoking, WTS poses unique risks of acute negative health outcomes including carbon monoxide poisoning and the spread of communicable diseases such as herpes and tuberculosis. Because waterpipe tobacco smoke contains the addictive chemical nicotine, youth who smoke tobacco from a waterpipe may be at risk for dependence. As a result, many youth may initiate WTS and continue to use despite negative health effects. Considering many of the potential negative health effects associated with WTS affect the pulmonary system, pulmonologists and primary care providers may treat patients who are waterpipe tobacco smokers and should be aware of the risk associated with WTS. The purpose of this review is to describe a waterpipe, the prevalence and correlates of WTS, the toxicants found in waterpipe tobacco smoke, the health effects of WTS, and implications for pulmonologists and other clinicians.

User identified positive outcome expectancies of electronic cigarette use: A concept mapping study.

Electronic cigarette (ECIG) use is growing in popularity, but little is known about the perceived positive outcomes of ECIG use. This study used concept mapping (CM) to examine positive ECIG outcome expectancies. Sixty-three past 30-day ECIG users (38.1% female) between the ages of 18 and 64 (M = 37.8, SD = 13.3) completed a CM module. In an online program, participants provided statements that completed a prompt: “A specific positive, enjoyable, or exciting effect (i.e., physical or psychological) that I have experienced WHILE USING or IMMEDIATELY AFTER USING an electronic cigarette/electronic vaping device is. . . .” Participants (n = 35) sorted 123 statements into “piles” of similar content and rated (n = 43) each statement on a 7-point scale (1 = Definitely NOT a positive effect to 7 = Definitely a positive effect). A cluster map was created using data from the sorting task, and analysis indicated a 7 cluster model of positive ECIG use outcome expectancies: Therapeutic/Affect Regulation, High/Euphoria, Sensation Enjoyment, Perceived Health Effects, Benefits of Decreased Cigarette Use, Convenience, and Social Impacts. The Perceived Health Effects cluster was rated highest, although all mean ratings were greater than 4.69. Mean cluster ratings were compared, and females, younger adults, past 30-day cigarette smokers, users of more “advanced” ECIG devices, and nonlifetime (less than 100 lifetime cigarettes) participants rated certain clusters higher than comparison groups (ps < 0.05). ECIG users associate positive outcomes with ECIG use. ECIG outcome expectancies may affect product appeal and tobacco use behaviors and should be examined further to inform regulatory policies.

Implications and challenges for implementation of the FDA’s final deeming rule for waterpipe tobacco

For the first time, the Food and Drug Administration’s (FDAs) Center for Tobacco Products now has regulatory authority over all tobacco products, including waterpipe tobacco. In the rule expanding its authority to cover all tobacco products, the FDA uses largely a one-size-fits-all approach. However, several aspects of waterpipe tobacco smoking make it unique from other tobacco products, which may require more specific, tailored rules. This paper describes the distinct features of waterpipe tobacco products and accessories, and identifies unique challenges to the current regulation posed by this form of tobacco use. Additionally, we highlight the need for further research-generated evidence to support additional rulemaking.

Hookah tobacco smoking in a large urban sample of adult cigarette smokers: Links with alcohol and poly-tobacco use

Hookah tobacco smoking (HTS) has been increasing, particularly among young adults and has similar health effects compared to cigarette smoking. The link between HTS and poly-tobacco use is well documented, but fewer show an association between HTS and alcohol use. It is essential to identify factors that increase the risk for or addictiveness and consequences of HTS, given its growing prevalence. This study examined whether the association between HTS and poly-tobacco use differed as a function of age and alcohol consumption within in a sample of 1223 adult cigarette smokers. Approximately 20% of participants reported HTS. Compared to non-users, hookah users were more likely to be male, highly educated, and to report drug and alcohol use, binge drinking, and poly-tobacco use but were less likely to be heavy smokers (≥10 cigarettes per day). Regression analyses predicting number of tobacco products used (excluding cigarettes and HTS) indicated a three-way interaction of HTS, frequency of alcohol use, and age such that the association between HTS and number of tobacco products used was strongest for younger respondents who consumed alcohol more frequently. As observed in previous studies, alcohol is an important risk factor in the relationship between HTS and poly-tobacco use, particularly among younger cigarette smokers. The links between alcohol, HTS, and poly-tobacco use should be considered when developing HTS education and prevention materials directed toward younger cigarette smokers. Findings provide information relevant to FDAs interest in the addiction potential of HTS and its link to poly-tobacco use.

Differences in puff topography, toxicant exposure, and subjective response between waterpipe tobacco smoking men and women.

Waterpipe tobacco smoking (WTS) exposes users to toxicants in much greater amounts than a cigarette. Little is known about how gender affects WTS toxicant exposure and subjective response. Data from three WTS clinical laboratory studies were combined for analysis. Participants (N = 99; 38 women) completed a 45-min WTS session where they smoked a waterpipe ad libitum. Puff topography was measured throughout, and plasma nicotine concentration, expired air carbon monoxide (CO), and subjective responses were measured pre- and post-WTS. There was a gender effect for total puff volume with men inhaling a greater smoke volume, on average (M = 59.9 L, SD = 40.7), compared with women (M = 38.8 L, SD = 27.8; p < .01). Men had greater post-WTS mean plasma nicotine concentrations (M = 10.0 ng/ml, SD = 7.1) compared with women (M = 6.9 ng/ml, SD = 5.2; p < .05). Post-WTS expired air CO was not associated with gender (men M = 27.6 ppm, SD = 18.9; women M = 22.7 ppm, SD = 17.0, ns). Relative to men, women had higher post-WTS scores for subjective measures of “nauseous,” “dizzy,” “nervous,” “headache,” and “heart pounding.” Men and women are exposed to toxicants during WTS, and men may achieve higher nicotine exposure than women, likely resulting from differences in smoke inhaled. However, similar post-WTS expired air CO between men and women and higher ratings of negative subjective responses among women may indicate that factors beyond puff topography may impact toxicant exposure and subjective response to WTS.

Toxicant inhalation among singleton waterpipe tobacco users in natural settings

Background Studies that assess waterpipe tobacco smoking behaviour and toxicant exposure generally use controlled laboratory environments with small samples that may not fully capture real-world variability in human behaviour and waterpipe products. This study aimed to conduct real-time sampling of waterpipe tobacco use in natural environments using an in situ device. Methods We used the REALTIME sampling instrument: a validated, portable, self-powered device designed to sample automatically a fixed percentage of the aerosol flowing through the waterpipe mouthpiece during every puff. We recruited participants at café and home settings in Jordan and measured puffing behaviour in addition to inhalation exposure of total particulate matter (TPM), carbon monoxide (CO), nicotine, polycyclic aromatic hydrocarbons and volatile aldehydes. We correlated total inhaled volume with five selected toxicants and calculated the regression line of this relationship. Results Averaged across 79 singleton sessions (52% male, mean age 27.0, 95% home sessions), sessions lasted 46.9 min and participants drew 290 puffs and inhaled 214 L per session. Mean quantities of inhaled toxicants per session were 1910 mg TPM, 259 mg CO, 5.0 mg nicotine, 117 ng benzo[a]pyrene and 198 ng formaldehyde. We found positive correlations between total inhaled volume and TPM (r=0.472; p<0.001), CO (r=0.751; p<0.001), nicotine (r=0.301, p=0.035) and formaldehyde (r=0.526; p<0.001), but a non-significant correlation for benzo[a]pyrene (r=0.289; p=0.056). Conclusions In the natural environment, waterpipe tobacco users inhale large quantities of toxicants that induce tobacco-related disease, including cancer. Toxicant content per waterpipe session is at least equal, but for many toxicants several magnitudes of order higher, than that of a cigarette. Health warnings based on early controlled laboratory studies were well founded; if anything our findings suggest a greater exposure risk.

Electronic cigarette explosion and burn injuries, US Emergency Departments 2015-2017.

Background Electronic cigarette (e-cigarette) battery failure can result in explosions and burn injuries. Previous attempts to quantify these events has been limited to compilations of case studies, federal agency reports and media reports. Although e-cigarette explosions and burn injuries are thought to be rare, current surveillance methods likely underestimate actual occurrences. Methods Analyses were conducted on cross-sectional data from the US Consumer Product Safety Commission’s (CPSC) National Electronic Injury Surveillance System (NEISS). A keyword search of case narrative text was used to identify e-cigarette-related explosion and burn injuries presenting to US emergency departments from 2015 to 2017. Sampling weights were applied to make conservative national incidence estimates. Results From 2015 to 2017, there were an estimated 2035 e-cigarette explosion and burn injuries presenting to US hospital emergency departments (95% CI 1107 to 2964). Conclusions There are more e-cigarette explosion and burn injuries in the USA than estimated in the past reports. Improved surveillance of e-cigarette injuries and regulation of e-cigarette devices is urgently needed. NEISS could be a valuable resource for e-cigarette injury surveillance.

Patterns and Correlates of Tobacco and Cannabis co-use by Tobacco Product Type: Findings from the Virginia Youth Survey

ABSTRACT Background: Cannabis use is more common among tobacco users than nonusers, and co-use (i.e., use of both substances individually) may be increasing. Better understanding of patterns and correlates of co-use is needed. The current study aimed to compare rates and correlates of tobacco and cannabis co-use by tobacco product among youth. Methods: High school students who completed the 2013 Virginia Youth Survey and reported past 30-day tobacco use (cigarette, smokeless tobacco, cigar) were included (n = 1390). Prevalence of past 30-day tobacco-only and cannabis co-use was calculated. Demographic, tobacco, and other substance use characteristics were compared by co-use status. Multivariate logistic regression models examined correlates of co-use overall and by tobacco product. Results: Over half of tobacco users were co-users. Poly-tobacco use, particularly combusted tobacco, was more prevalent among co-users. Past 30-day alcohol use and lifetime other illegal drug use/prescription drug misuse were common correlates of co-use. Black Non-Hispanic (NH) race/ethnicity was associated with co-use when restricted to cigarette users. “Other” race/ethnicity was associated with co-use in the overall model and when restricted to cigar users. Past 30-day cigarette smoking was associated with co-use in all models except among cigar smoking co-users. Conclusions/Importance: Rates and correlates of tobacco and cannabis co-use were not uniform and differed by tobacco product type. Tobacco and cannabis co-users may be at greater risk for negative health effects associated with inhaled tobacco and other risky substance use. The efficacy of prevention efforts may be improved if risk factors associated with product-specific co-use are considered.