E-Cigarettes, Harm Reduction, and Tobacco Control: A Path Forward?

Longitudinal Assessment of Association Between Tobacco Use and Tobacco Dependence Among Adults: Latent Class Analysis of the Population Assessment of Tobacco and Health Study Waves 1-4

INTRODUCTION

With increasing tobacco product varieties, understanding tobacco use (TU) profiles and their associations with tobacco dependence (TD) has also become increasingly challenging.

AIMS AND METHODS

We aimed to identify TU profiles and their associations with TD over time, and to identify subgroups with high risk of TD. We included 3463 adult recent tobacco users who had complete TU and TD data across waves 1-4 of the Population Assessment of Tobacco and Health (PATH) study. We used a composite index of TD and a summed TD score from an established 16-item TD measure. We applied a latent class analysis to identify TU profiles based on participants' usage of eight common tobacco product groups at each survey wave and to check the stability of the TU profiles over time. We then used generalized estimating equations regressions to evaluate the longitudinal TU-TD association, adjusting for potential confounders.

RESULTS

We identified three distinct TU profiles that remained consistent across four survey waves: Dominant cigarette users (62%-68%), poly users with high propensity of using traditional cigarettes, e-cigarettes, and cigars (24%-31%), and dominant smokeless product users (7%-9%). Covariate-adjusted models showed that TD was significantly lower among the poly users and the dominant smokeless users, compared to that among the dominant cigarette users.

CONCLUSIONS

Both TU profiles and their associations with TD were stable over time at the population level. Poly users and smokeless product users were consistently associated with lower TD than cigarette-dominant users, suggesting the need for tailored tobacco cessation interventions for users with different TU profiles.

IMPLICATIONS

The finding of consistent TU profiles across four survey waves extends the current literature in capturing TU patterns in an evolving tobacco product landscape. The finding of the overall higher level of TD among the cigarette-dominant users compared to the other TU latent profiles (the Cig+eCig+Cigar dominant poly users and the dominant smokeless product users) can help identify high-risk groups for potential interventions. Our application of innovative statistical methods to high-quality longitudinal data from the PATH study helps improve the understanding of the dynamic TU-TD relationship over time.

Perceiving E-Cigarettes as Safe and Safer Alternative to Cigarettes Among Young Adults

BACKGROUND

Young adults are using e-cigarettes at high rates. While the literature on the health risks associated with e-cigarettes is extensive and growing, little is known about young adults' thoughts and perceptions of the safety and harms of e-cigarettes.

METHODS

We conducted one-on-one interviews with young adults aged 18 to 25 years in Los Angeles, California between June 2018 and June 2019. We interviewed and audio-recorded young adults (N = 62) who consented to the study and self-reported to have used e-cigarettes on a weekly basis or more for at least 5 months prior to study enrollment. Interviews examined participants' thoughts, feelings, and experiences related to e-cigarette use. We audio-recorded, transcribed, and coded the interviews using grounded theory analysis methods.

RESULTS

Young adults often believed that e-cigarettes were safer than cigarettes and were safe to use, especially following positive vaping experiences. Young adults were skeptical of the available science on e-cigarette use and felt there was not conclusive data on the harms of e-cigarettes. In their selection of e-cigarettes over cigarettes, young adults felt they were making a conscious and healthier choice. Because young adults viewed e-cigarettes to be better for them based on their personal experiences with vaping, they felt e-cigarettes were a superior alternative to combustible tobacco.

CONCLUSIONS

Young adults in our study believed that the long-term health effects of e-cigarette use are not clearly understood and were generally skeptical of the research on e-cigarette harms. Policy, education, and anti-smoking campaigns need to clarify the negative health-related consequences of e-cigarette use for young people.

Characterization of moisture migration and diffusion in two types of tobacco biomass during the dehydration process by the TG-NMR analysis

The tobacco waste generated from the tobacco agriculture and industry, including the discarded stem and leaf, often needs dehydration pretreatment before thermal conversion utilization. In order to study the water activity and migration of tobacco waste during the pretreatment process, TG-NMR (Thermogravimetric Nuclear Magnetic Resonance) was used to obtain the drying curves and LF-NMR (Low Field Nuclear Magnetic Resonance) T2 inversion spectrum at each stage of tobacco drying. Meanwhile, the variation pattern of pore distribution during the dehydration process of two types of tobacco waste has been obtained. Combined with the pore distribution changes, a possible spatial migration mode of water was proposed. The change of adsorption energy of water during tobacco drying was calculated, and verified the above hypothesis. This study results provide reference for the optimization of dehydration pretreatment process for different tobacco waste in order to reduce energy consumption during recycling of tobacco biomass.

Harm perceptions of vaping nicotine relative to cigarette smoking among sexual and gender minority young adults

INTRODUCTION

To address gaps in existing research, the current study used a mixed-methods approach to describe, contextualise and understand harm perceptions of vaping nicotine relative to cigarette smoking and associations with nicotine and tobacco (NT) use among young adults who identify their genders and sexualities in ways that classify them as sexual and gender minorities (SGM).

METHODS

Results are based on cross-sectional surveys and online qualitative interviews with 98 SGM young adults (18-25 years old) in California's San Francisco Bay Area who currently or formerly used combustible tobacco. We generated a measure assessing participants' relative harm perceptions of e-cigarette use versus cigarette smoking and identified those who perceived cigarette smoking as more harmful than e-cigarette use compared to those who perceived it to be equally or less harmful.

RESULTS

We found that relative harm perceptions of cigarette smoking versus e-cigarette use are likely related to much uncertainty and confusion about the harms of e-cigarette use. Moreover, findings illustrate that public health messages regarding the risks of e-cigarette use may have unintended consequences of increasing cigarette use to replace e-cigarette use for some SGM young adults, a practice that is incongruent with scientific evidence demonstrating that cigarettes and other combustible tobacco products are riskier than e-cigarettes and other forms of NT use.

DISCUSSION AND CONCLUSIONS

Results suggest the need for evidence-based, clear, and direct messaging about the relative harms of cigarettes versus e-cigarettes to reduce NT-related inequities in SGM populations.

E-cigarette Price Impacts legal and Black-Market Cigarette Purchasing Under a Hypothetical Reduced-Nicotine Cigarette Standard

INTRODUCTION

The Tobacco Control Act gives the U.S. Food and Drug Administration authority to establish a reduced-nicotine content standard in combusted cigarettes. This future potential regulation may pose a significant public health benefit; however, black markets may arise to meet demand for normal-nicotine content cigarettes among smokers unwilling to transition to or use an alternative product.

AIMS AND METHODS

We determined the behavioral-economic substitutability of illicit normal-nicotine content cigarettes and e-cigarettes for reduced-nicotine content cigarettes in a hypothetical reduced-nicotine regulatory market. Adult cigarette smokers were recruited online to complete hypothetical cigarette purchasing tasks for usual-brand cigarettes, reduced-nicotine content cigarettes, and illicit normal-nicotine content cigarettes, as well as a cross-commodity task in which reduced-nicotine content cigarettes were available across multiple prices and illicit cigarettes were concurrently available for $12/pack. Participants completed two three-item cross-commodity purchasing tasks in which e-cigarettes were available for $4/pod or $12/pod alongside reduced-nicotine content cigarettes and illicit cigarettes.

RESULTS

Usual-brand cigarette purchasing was greater than illicit normal-nicotine content cigarettes and less than reduced-nicotine content cigarettes. In the cross-commodity purchasing tasks, illicit cigarettes and e-cigarettes both served as economic substitutes for reduced-nicotine content cigarettes; however, when e-cigarettes were available for $4/pod, they were purchased at greater levels than illicit cigarettes and resulted in greater reductions in reduced-nicotine content cigarettes purchasing than when available for $12/pod.

CONCLUSIONS

These data suggest that some smokers are willing to engage in illicit cigarette purchasing in a reduced-nicotine regulatory environment, but e-cigarette availability at lower prices may reduce black-market engagement and shift behavior away from combusted cigarette use.

IMPLICATIONS

E-cigarettes available at low, but not high, prices were stronger substitutes for legal, reduced-nicotine content cigarettes than illegal, normal-nicotine content cigarettes in a hypothetical reduced-nicotine tobacco market. Our findings suggest the availability of relatively inexpensive e-cigarettes may reduce illicit cigarette purchasing and combusted cigarette use under a reduced-nicotine cigarette standard.

Assessment of inhalation toxicity of cigarette smoke and aerosols from flavor mixtures: 5-week study in A/J mice

Most flavors used in e-liquids are generally recognized as safe for oral consumption, but their potential effects when inhaled are not well characterized. In vivo inhalation studies of flavor ingredients in e-liquids are scarce. A structure-based grouping approach was used to select 38 flavor group representatives (FGR) on the basis of known and in silico-predicted toxicological data. These FGRs were combined to create prototype e-liquid formulations and tested against cigarette smoke (CS) in a 5-week inhalation study. Female A/J mice were whole-body exposed for 6 h/day, 5 days/week, for 5 weeks to air, mainstream CS, or aerosols from (1) test formulations containing propylene glycol (PG), vegetable glycerol (VG), nicotine (N; 2% w/w), and flavor (F) mixtures at low (4.6% w/w), medium (9.3% w/w), or high (18.6% w/w) concentration or (2) base formulation (PG/VG/N). Male A/J mice were exposed to air, PG/VG/N, or PG/VG/N/F-high under the same exposure regimen. There were no significant mortality or in-life clinical findings in the treatment groups, with only transient weight loss during the early exposure adaptation period. While exposure to flavor aerosols did not cause notable lung inflammation, it caused only minimal adaptive changes in the larynx and nasal epithelia. In contrast, exposure to CS resulted in lung inflammation and moderate-to-severe changes in the epithelia of the nose, larynx, and trachea. In summary, the study evaluates an approach for assessing the inhalation toxicity potential of flavor mixtures, thereby informing the selection of flavor exposure concentrations (up to 18.6%) for a future chronic inhalation study.

Smokeless tobacco and cigarette smoking: chemical mechanisms and cancer prevention

Tobacco products present a deadly combination of nicotine addiction and carcinogen exposure resulting in millions of cancer deaths per year worldwide. A plethora of smokeless tobacco products lead to unacceptable exposure to multiple carcinogens, including the tobacco-specific nitrosamine N'-nitrosonornicotine, a likely cause of the commonly occurring oral cavity cancers observed particularly in South-East Asian countries. Cigarettes continue to deliver a large number of carcinogens, including tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons and volatile organic compounds. The multiple carcinogens in cigarette smoke are responsible for the complex mutations observed in critical cancer genes. The exposure of smokeless tobacco users and smokers to carcinogens and toxicants can now be monitored by urinary and DNA adduct biomarkers that may be able to identify those individuals at highest risk of cancer so that effective cancer prevention interventions can be initiated. Regulation of the levels of carcinogens, toxicants and nicotine in tobacco products and evidence-based tobacco control efforts are now recognized as established pathways to preventing tobacco related cancer.

Tobacco Harm Reduction as a Path to Restore Trust in Tobacco Control

The controversy of tobacco harm reduction in the United States persists despite evidence that an important audience of tobacco prevention and control, i.e., the people who use or are likely to use nicotine and tobacco products, are engaging in practices that may be considered harm reduction. Despite this, a significant proportion of the US tobacco control and prevention field continues to be guided by a precept that there is "no safe tobacco," therefore failing to acknowledge practices that may be used to reduce the harms associated with consuming combustible forms of nicotine and tobacco. In this commentary, we argue that ignoring the potential benefits of harm reduction strategies may unintentionally lead to an erosion of trust in tobacco control among some members of the public. Trust in tobacco control as an institution is crucial for the success of tobacco control efforts. To ensure trust, we must return to our basic principles of doing no harm, developing programs that are responsive to people's experiences, and providing resources in assisting people to reduce the harms that may be associated with practices, such as smoking, which adversely affect health. Only by respecting an individual's priorities can we cultivate trust and develop tobacco prevention efforts that are grounded in the realities of people's lives and responsive to their needs.