Not just water vapour

This is likely to be baseless. Unlike vapourised water, electronic nicotine delivery system (ENDS) emissions comprise nicotine, carbonyls, metals, organic volatile compounds, besides particulate matter,4 and putative carcinogenic polycyclic aromatic hydrocarbon.5 ,6 Moreover, the high concentrations of nanoparticles in vape, despite their small mass, may have significant toxicological impact.7 This is likely due to their increased ability for deep penetration into the pulmonary and cardiovascular systems.5

Importantly, the short time span since the advent of ENDS and the latency of candidate respiratory and cardiovascular diseases that may be caused or exacerbated by ambient exposure to ENDS emissions preclude definitive risk inference.7 Taking the current immature evidence as a proof of safety and using it to advocate for policy that allows ENDS indoors could prove reckless.

Recent reports of rapid-onset changes in aortic stiffness after exposure to vape,8 of mice exposed to vape with nicotine developing features of chronic obstructive pulmonary disease9 and a 2014 report of increases in fractional exhaled nitric monoxide (FeNo),5 a marker of eosinophilic airway inflammation, following vaping are examples of possibly vanguard research findings that may prove important.

Vaping on aircraft presents catastrophic risk because of the risk of explosions and fires.10 The unregulated vaping gear industry, with amateurs also modifying equipment, remains an ongoing risk in this respect. Many combustible products have long been prohibited on aircraft in carry-on and checked baggage.

Real world exposures

While documented indoor concentrations of exhaled vape constituents are often lower than those arising from cigarettes,9 real world scenarios can involve significant exposure. Scenes from ‘vapecons’ abound on YouTube,11 where large numbers of ENDS users participate in ‘clouding’ contests, show worst case scenarios (eg, http://www.youtube.com/watch?v=4NPe3rAYG_Q&t=0m46s). The air in such settings is visibly and constantly thick with vape. In a recent study,12 PM_2.5 counts were measured in a 4023 m³ room at a vapecon over six occasions when between 59 and 86 active ENDS users were present. Median PM_2.5 concentrations in the room increased from a baseline of 1.92–3.20 µg/m³ to concentrations ranging from 311.68 to 818.88 µg/m³; 125–330 times higher than in the same room when empty and higher than PM_2.5 concentrations recorded in bars where cigarette or waterpipe smoking were allowed.13

Vaping advocates acknowledge wide variations in public vaping practices, asserting that while some ‘take joy in producing huge clouds of vapour’ others ‘wish to produce as little fog as possible’ and ‘produce so little visible fog that they vape freely in public–at work, in meetings, in restaurants, and in planes, trains and buses.’ And it is even seriously claimed that ‘nobody even notices’.14

Public policy needs to deal with this diversity and assume more than the most discreet, low-key scenarios. If vaping were allowed indoors, would any restrictions apply? Would bar staff be required to limit the number of people vaping, or request or order them to be discreet or ‘considerate’ with their exhalations as with the ineffective approaches that were once made for smokers?15 Will arguments occur about whether a plume is excessive? Should and how might ‘clouding’ be forbidden? Will airlines allow a maximum of five passengers to vape but not 50? How will those charged with enforcing smoke-free measures, whether in public places or locations such as cars and buses where children can be heavily exposed, distinguish between smokers and vapers? Good luck with all of that.

The history of smoke-free policy saw early ludicrously ineffective and discredited efforts to accommodate continuing smoking indoors such as ‘magic line’ divisions between smoking and non-smoking sections;16 courtesy campaigns17 and ventilation.18 The folly of these efforts should not be repeated with exposure to vaping.

Helping smokers quit versus triggering relapse in former smokers?

By allowing vaping in all currently smoke-free indoor public and workplace areas, it is also asserted that many smokers not yet vaping may see this as an attractive benefit and take it up. This is a factor cited by some youth for trying ENDS.19 While some smokers would quit smoking with ENDS, many more would engage in dual use.20 Given that smoke-free policies have been important drivers of smoking reduction and cessation,21 it is plausible that being able to vape in public places may in fact dampen decisions to quit or lead to relapse for many. Indeed, experimental evidence suggests that exposure to ENDS advertising22 ,23 and imagery24 may stimulate smokers and ex-smokers to try ENDS, smoke more cigarettes or relapse to smoking.16 ,17

Another argument used by indoor vaping advocates is that indoor vaping bans will cause former smokers who now vape to go outside, where exposure to sensory cues from exiled cigarette smokers will trigger their relapse back to smoking. This would be all the fault of non-smokers selfishly putting their own health and comfort ahead of vapers and contributing to their stigmatisation.25 By this argument non-smokers should be happy to be exposed to ambient vape in aircraft, workplaces, restaurants and bars (or even sustained clouding sessions) to make ENDS users feel more ‘included’ and in the hope that they might quit smoking.

Renormalisation of the smoking performance

The ENDS industry's business model involves promoting vaping as an alternative to smoking. But only the most disingenuous or naïve could deny that the prospect of attracting the far more numerous non-smokers, particularly youth, to vaping would be their only long-term sustainable business model.26 Policies which maximise public exposure to vaping will likely be essential to recruiting new consumers of various tobacco/nicotine products.

A collateral beneficial effect of smoke-free policy has been the denormalisation of smoking. This has seriously eroded the tobacco industry goal of allowing smoking to occur without restriction, and portraying smoking as a normal, highly desirable behaviour. All major tobacco companies have invested heavily in ENDS but have not desisted from aggressive tobacco marketing, targeting disadvantaged groups or opposing effective tobacco control measures. They want people to smoke or smoke and vape, not vape instead of smoke. With the vaping performance or ‘act’ sharing much with the smoking act, the tobacco industry would hold high hopes of renormalising the use of its traditional and immensely profitable products. This is likely to cue interest in vaping in non-smokers and ex-smokers, an outcome far removed from the ostensible putative benefits of having only smokers switch.27 It will also erode the benefits achieved by non-smoking policies over many years in ensuring that children do not see smoking behaviour as normal and acceptable.

If ENDS emissions were really benign, indoor vaping advocates should take courage and call for it to be allowed in classrooms, crèches, hospitals and neonatal wards. That they do not rather suggests that they know well that such a position would be irresponsible.

Finally, and with delightful irony, the 2016 Global Forum on Nicotine, (focused on ENDS and including leading ENDS advocates) banned ENDS use by delegates in conference areas. The organisers' plea that delegates in public areas “please be discreet and considerate. Use low powered devices as it helps to keep the amount of vapour created to a minimum” could not be more revealing.28