by Carl V Phillips
A funny thing appeared in the abstracts for the upcoming meeting of the Society for Research on Nicotine and Tobacco (SRNT). Buried amidst the few dozen abstracts about e-cigarettes from the “public health” people is some actual public health research (i.e., research that could inform messages and regulation that would help people be healthier).
Most of the abstracts on e-cigarettes are just dumb make-work projects, presumably by people trying to justify their employment. There are numerous surveys of attitudes, which mostly just reflect how the questions were asked and are changing by the month, and other variations on how to provide no useful information other than perhaps a historical record about the social dynamics of THR adoption (I will probably try to mine them for that).
Not surprisingly, many of the supposed social science projects violate the ethical norms of social science by using the concocted term “ENDS” rather than using the population’s preferred terminology for e-cigarettes. This offers absolutely no scientific benefit (e.g., it does not more precisely define the behavior) and was clearly designed to be somewhat derogatory, but most of all it is designed to assert researcher primacy over a population’s own self-identity. Some types of scientists can make up words when they are helpful, and political actors can have some fun with it when describing the powerful (e.g., “ANTZ”); people doing sociological research are ethically obliged to respect the populations they are studying. Imagine researchers making up a patronizing name to refer to a self-identifying ethnic/cultural group; their writing would generate serious deserved backlash and be refused by any respectable journal or research organization. This alone says a lot about these “researchers” and SRNT.
Most of the abstracts contain disinformation and, indeed, the one that I am highlighting has disinformation built into it (see below) despite its possible value. It is by Alan L. Shihadeh and Thomas Eissenberg, who unlike their SRNT colleagues seem to be trying to do useful work and have some inkling of what useful science looks like.
(However, in spite of his increasingly valuable contributions, I believe the latter still owes the world an apology and/or retraction for his widely-cited publication that claimed that e-cigarettes do not deliver nicotine. Politicians and activists make errors like that all the time and then pretend it never happened; scientists who make the mistake of epistemic immodesty need to rise to a higher ethical standard. In science, the phrase “our one-off limited empirical study found something contrary to what all the previous evidence suggests” should always be followed by “so we probably did something wrong, so please ignore this result until we do additional research” rather than by “and therefore what everyone knew before was wrong” (or, better still, they should do the additional research to explain the discrepancy before publishing). He does however get credit for trapping the ANTZ into starkly illustrating that science is just window-dressing to them and they do not really care what it shows: When they were foolish enough to believe his claim, they condemned e-cigarettes as failures because they do not provide nicotine. After it became clear that his claim was wrong, they condemned e-cigarettes because they effectively deliver evil evil nicotine.)
The abstract (or just skip down to my observations about it if you are in a hurry – there is really just one important point in it):
Background: “Electronic cigarettes” (ECIGs) heat a nicotine-containing solution to produce a vapor for inhalation. There is considerable variability in device characteristics and puff topography and each of these factors may be related to vapor toxicant content.
Method: We investigated the role of device voltage and puff duration on vapor toxicant content. We examined total particulate matter, nicotine, and volatile aldehyde emissions from 15 consecutive puffs of V4L™ ECIG cartridges (18 mg/ml nicotine) while varying device voltage (3.7 vs 5.2 volts) and machine-produced puff duration (1.8 vs 3.6 s). We used a puff velocity of 38.8 ml/s and 10 s interpuff interval (Goniewicz et al., 2012). In another study, we investigated a non-cartridge ECIG use method that involves dripping nicotine containing liquid directly onto a heating element and inhaling the resulting vapors. We measured aldehyde emissions from dripping 3 drops of e-liquid (16 microL, similar to the amount of e-liquid consumed in 15 e-cig puffs) onto a 300 C heater surface.
Results: The higher voltage tripled vapor nicotine content, and doubling puff duration doubled nicotine content. We also found that longer puffs resulted in greater cartridge temperatures, and that, for a given puff duration, higher puff velocities resulted in lower temperatures. Dripping liquid onto a heater surface produced more than 200 micrograms of formaldehyde, compared to 0.03 micrograms for 15 puffs of an ECIG cartridge (V4L™cartridge, topography of Goniewicz et al., 2012). We also measured 2-20 fold greater emissions of other aldehydes (9 species in total).
Conclusions: Overall, these results demonstrate that device characteristics (e.g., voltage), puff topography, and use behavior (i.e.,“dripping”) can influence vapor toxicant content. Indeed, these findings suggest that ECIG aficionados who take longer duration, slower puffs (Hua et al., 2011) are working to obtain higher nicotine doses and that those who drip liquid directlyon the heater (McQueen et al., 2011) risk significant exposure to formaldehyde that is a human carcinogen and is associated with COPD in conventional tobacco product users.
Most of the results fall into the “incredibly obvious” category: Faster puffs result in lower temperatures (because more cool liquid moves across the atomizer, cooling it faster than it can heat). Longer puffs extracted more nicotine, approximately proportional to the length of the puff (anyone surprised by that?).
It was interesting to see how much delivery (reported as nicotine quantities, but that is obviously just a measure of how much total liquid was aerosolized) increased with the increase in voltage. This, of course, is not some universal finding for the ages, like something that might be discovered about the behavior of a molecule (though undoubtedly countless naive readers will interpret it as such). Every result in this research depends heavily on the exact variables of the equipment and other methods they were using, and every device and every user is different. But the authors get credit for actually varying a few of the variables a bit. Reading most of the research on e-cigarettes would give the impression that there are no such variables, so actually the authors get a lot of credit for starting to correct that error.
The result that is potentially real health-affecting knowledge (unlike, as far as I can tell, every other bit of research on e-cigarettes in the SRNT abstracts) is the result of dripping e-cigarette liquid onto a heater at 300C. This result is, unfortunately, also the germ of more disinformation because this is far hotter than what actually occurs (except, perhaps, with a seriously ill-advised novelty mod). This presumably explains why the concentration of formaldehyde they found is enormously higher than that observed in analyses of real e-cigarette vapor. Even if you preheat an atomizer to that temperature before dripping on it, it will rapidly cool toward an equilibrium temperature. I am guessing that the “heater surface” they used was a piece of lab equipment that has a much larger mass than an atomizer filament, and thus maintained close to the original temperature rather than rapidly cooling when the first bit of liquid touched it.
We can safely assume that some people will spin this result as showing that e-cigarettes generate this quantity of formaldehyde, and thus the way the information was presented is a gift to the liars. (Perhaps such an offering to the liars is the price of admission to SRNT.) Still, this might offer a genuine contribution to health. It does suggest that using very-high-temperature mods or a high preheating of the atomizer (by holding the switch on for too long before starting to draw) might increases vapors’ health risks. Even if most of the liquid would not be heated to 300C, a bit of it might. That is intuitive if you think about it: higher peak temperature = more pyrolysis = more nasty chemicals. But it is not clear there has been much thinking about it.
There should be more. Good scientists who have more knowledge than I about the chemistry should really think this through — a little bit of theory and existing general knowledge would be worth for more than a series of one-off experiments on particular equipment. If there is going to be any actual health-improving research about e-cigarettes, it obviously will not be the attempts to demonize them out of existence, but it also cannot be the attempts to claim everything about them is always just fine. Real public health researchers do not behave like “public health” people who just look for an excuse to say “never do this, no matter how much you want to”; they figure out how to advise “if you are going to do this, you are better off doing it this way….” This is, of course, the reasoning behind THR in the first place, and also describes what real health research about nicotine inhaler technologies should look like. I suspect that most of this public health learning will have to wait until the tobacco companies report what they are doing, but it is good that at least one independent research team is headed in that direction.