Participants reported the appeal of electronic vaporisers for nicotine and marijuana

Nationally, young adults have the highest rates of current marijuana use, with 18.9% aged 18–25 years using in 2013, compared to 7.1% aged 12–17 years and 5.5% aged ≥26 years.According to 2014 data, almost 30% of young adults in Colorado reported current marijuana use.Young adults also have the highest current rates of tobacco smoking .More young adults have ever tried e-cigarettes compared to other age groups.Rates of dual and poly use are also high: in 2013, among US young adults who smoked cigarettes in the past 30 days , 47% were current marijuana users.Given high rates of co-use of tobacco and marijuana among young adults,as well as transformations in the realm of policy and technology, tobacco, marijuana and vaporisers are most effectively studied in relationship to one another.Referred to as ‘the triangulum’ , this approach reflects interest in the intersection of tobacco, marijuana and electronic vaporiser use, with implications for surveillance , policy and treatment .Several quantitative studies examined some aspects of the triangulum, including co-use of combustible tobacco and marijuana,perceptions of comparative harm of tobacco and marijuana,prevalence of vaporiser use among marijuana users and reasons for use of marijuana vaporisers.Two qualitative studies examined the intersection of tobacco and marijuana by interviewing youth in Scotland.The data in the studies, however,rolling hydro tables were collected over a decade ago and do not reflect changing legal and normative environments around marijuana or the proliferation of vaporising devices.

Several quantitative studies have addressed marijuana vaporisers use by adults, including Lee et al and Etter,but neither was designed to explore in depth why users choose to vaporise marijuana, or the social or policy contexts shaping vaporiser use. To the best of our knowledge, this is the first in-depth, qualitative investigation of the triangulum in the ‘natural laboratory’ of Colorado. We interviewed young adults in Colorado to understand how they use, perceive and ascribe meaning to various tobacco, marijuana and vaporiser products.As part of the State and Community Tobacco Control research initiative , this project was developed in strategic partnership with Denver Public Health and Jefferson County Public Health departments in Colorado. Beginning in early 2014, we worked with local agencies to identify research questions that would advance policy solutions and practice. These questions were further refined iteratively throughout the data collection period. Local agencies provided staff to recruit participants, assisted with interviewing, provided space for interviews and engaged key stakeholders in reviewing early findings.Participants were recruited using flyers placed in marijuana dispensaries, vape shops, cafes, stores and on bulletin boards at community colleges in the Denver Metro area. Online recruitment was conducted through Craigslist and posting on Facebook. Inclusion criteria included being 18–26 years old and current use of at least one of the three products . Prospective participants were screened and enrolled in the study via telephone by trained research staff. We attempted to interview all 32 enrolled participants twice, in order to allow conversations to develop more deeply. Twenty-four completed both interviews. Participants were compensated $35 for the first interview and $65 for the second.

Each participant gave written consent. All study protocols were approved by the Committee on Human Research at the University of California, San Francisco.Semi-structured interviews were conducted between January and August 2015 by six trained interviewers , following a standard interview guide. Interviews were conducted individually in public places or in meeting rooms in local health departments. Before each interview, participants completed brief questionnaires with demographic information and past tobacco and marijuana use history. Discussion topics included definitions of smoking, experiences with tobacco, e-cigarettes, marijuana, marijuana vaporisers and other products, perceived benefits and risks of products and experiences with marijuana legalisation in Denver. Interviews lasted between 60 and 90 min, and were audio recorded.Audio recordings were professionally transcribed. Data were coded using Dedoose software. Researchers McDonald and Popova independently blind-coded a subset of transcripts, which were then compared to develop coding guidelines. Researchers created code definitions and developed a consistent coding scheme to ensure that codes were applied consistently. The larger set of transcripts was divided and coded independently. Themes were generated iteratively during review of coded transcripts. Memos summarising each theme with illustrative quotes were reviewed by authors and discussed iteratively to reach consensus and theme saturation. Pseudonyms are used for all participants quoted in this article and no real names have been used.Participants highlighted fluidity between use of tobacco, marijuana and vaporisers. Reflecting this fluidity, the terms ‘smoke’ and to be a ‘smoker’ were used to describe either tobacco or marijuana use in ways that left unclear which substance was referred to.

While dual and poly use was our primary focus, some participants also reported co-use through merging products, including use of tobacco wraps or little cigars/ cigarillos to smoke marijuana and the use of tobacco cigarettes to ‘extend’ the effects of marijuana. Vaporising devices were used to consume either nicotine or marijuana concentrates, with such devices nearly indistinguishable in appearance. Participants remarked upon the increasing popularity of ‘vaping’, expanded interest in vaporisers for nicotine and marijuana products and the convenience of vaporisers for use in public spaces. In some contexts, participants clearly distinguished between tobacco, marijuana and vaping, as they did when discussing the risks of secondhand smoke. Participants viewed secondhand tobacco smoke as potentially dangerous, often limiting or prohibiting use of combustible tobacco in homes or cars. Marijuana secondhand smoke, in sharp contrast, was widely considered safer and more pleasant smelling than tobacco smoke, with few participants restricting combustible marijuana indoors.Our question ‘Do you smoke?’ was frequently met with the question: ‘smoke what?’ The term ‘smoking’ was used interchangeably to refer to the use of marijuana or tobacco, with this ambiguity only uncovered through conversation: when a researcher asked ‘Ethan’, ‘In terms of your social circle in Colorado, do many people smoke?’ ‘Ethan’ responded, ‘[e] veryone that I work with under the age of 30 smokes. I have five roommates and they all smoke. Just about everyone I know in Denver smokes. I have one friend that doesn’t, just because he gets panic attacks’. When the researcher asked whether these friends were regular or occasional smokers, ‘Ethan’ responded, ‘Much more regular marijuana smokers…[pause] are we still talking about tobacco smoking? When I hear “smoking” now, I associate it more with marijuana than tobacco smoking’. ‘Ethan’ clarified that among his friends,vertical horticulture only five were regular tobacco smokers, whereas the majority smoke marijuana. In Colorado, he elaborated, the term ‘smoke’ primarily indicates use of marijuana, but added, ‘If I go back to Texas, and somebody says, “I’m going to go for a smoke,” I know [they mean] cigarettes— tobacco’. When asked if he ever smoked while drinking, ‘Owen’, 20, commented, ‘Yeah… if I have one drink I’ll probably be smoking before, you know?’ When the researcher asked him to clarify whether he meant smoking marijuana or tobacco, he responded, ‘Marijuana. I don’t really smoke tobacco products like that. The only reason why I put 20 times [of tobacco use per month on the questionnaire] is because [of ] Swisher Sweets[cigarillos]. I’d have to get a Swisher Sweet to roll up the marijuana, you know?’. He added that he would not smoke cigarillos ‘straight’, but only as a wrap for marijuana.

The emerging issues uncovered in this qualitative study highlight the need to reconsider the traditional silo-based approach to tobacco control and marijuana research. It is particularly important to consider the triangulum of tobacco, marijuana and vaporisers, and we believe this is the first study to address this intersection in the context of legalised marijuana. We found widespread ambiguity about whether ‘to smoke’ referred to the use of tobacco or marijuana products. While not unique to Colorado, this linguistic equivalence between tobacco and marijuana use may signal increasing normalisation of marijuana. Researchers should be aware of this ambiguity in designing precisely worded research instruments. Additionally, anti-tobacco messaging that focus on ‘smoke’ or ‘smoker’ identity may be diluted in this context, as combustible marijuana moves towards legality and widespread availability. Participants reported the use of tobacco products as part of the consumption of marijuana. This points to several key issues. Tobacco products are used as a delivery method for marijuana because of convenience and/or to facilitate sharing, even when tobacco products are not explicitly desired. Therefore, tobacco consumption may increase and become normalised even in the absence of the desire to use tobacco. Second, as noted previously,participants reported using traditional tobacco cigarettes to extend the ‘high’ of marijuana consumption, particularly because of tobacco’s comparatively lower cost. Third, participants did not uniformly agree whether the use of tobacco products for consuming marijuana ‘counted’ as using tobacco. This may lead to a significant under-reporting of current tobacco use. For example, the participant who reported using tobacco products 3 days of the last 30 on the questionnaire revealed during his interview that he used tobacco wrappers for marijuana 30 days out the past 30 . It was not until specifically asked about his method of marijuana consumption that it became evident he was a daily tobacco user. Tobacco researchers should be aware that tobacco products used to consume marijuana may not be reported as tobacco use, and should specifically ask about the use of blunt wraps and cigarillos for marijuana consumption. While this issue has been raised before,with at least one nationally representative survey asking about cigarillos for marijuana consumption,it has not been widely adopted and will become increasingly critical as marijuana is more widely legalised. Some participants used the same vaporiser for both products , while others reported owning devices for each. Although past studies showed that vaping was less common than smoking marijuana among a convenience sample of adults,given the rapid growth of the marijuana vaporiser industry and the growing popularity ofelectronic vaporisers, especially in states with legalised medical marijuana,it is essential to study perceptions and practices related to electronic vaporisers for marijuana. Reduced odour was frequently mentioned in the appeal of marijuana vaporisers, cited as advantageous when consuming marijuana in public spaces . Those wishing to vaporise marijuana in public may benefit from the broader normalisation of nicotine vaporising , as the similar appearance of the devices may make it difficult for the passers-by or law enforcement to identify which product is being consumed. This was experienced negatively by some participants who exclusively vaporise nicotine, as they felt falsely identified as marijuana users. Communities concerned about the use of marijuana in public spaces should consider including all vaporisers in smoke-free regulations to prevent this confusion. Additionally, there is a concern that growing popularity of vaping, for tobacco and marijuana, might renormalise smoking.Participants clearly differentiated between secondhand tobacco and secondhand marijuana smoke. Many were quick to cite the dangers of tobacco, including secondhand smoke, and enforced rules determining where combustible tobacco could and could not be used in their own spaces. In contrast, marijuana smoke was largely regarded as benign, neutral or even pleasant. Few participants expressed concern about secondhand marijuana smoke, or limited where combustible marijuana could be used. This was, in part, due to the subjective experiences of marijuana smoke being much ‘milder’ than tobacco smoke, and dissipating more quickly. Participants also reported that aerosol produced by vaporisers , whether nicotine or marijuana, smelled less strongly than combustible smoke, and generally allowed its use indoors. This is in contrast to a study in Georgia that found 83% of surveyed college students adopted smoke-free policies for marijuana and 86% for tobacco in their homes.State policies around legal marijuana might affect young adults’ personal smoke-free rules. Our participants reported that smoking combustible marijuana indoors was often the only viable option available. Colorado law prohibits the use of marijuana in public places . Since many of our participants lived in lower income, multi-unit housing, they did not often have private outdoor spaces where they could legally smoke marijuana. Their choice, therefore, was either to break the law and smoke marijuana in an outdoor public space, or, following the law, smoke combustible marijuana in indoor, home spaces. Furthermore, ‘no smoking’ signs in housing units and other spaces were sometimes unclear, with young adults unsure whether prohibitions were limited to tobacco or included marijuana.