Putting aside the notion that trying to prevent people from enjoying a bad health habit that largely hurts only themselves has anything to do with "public health," it is quite perplexing that so many anti-tobacco nannies are stridently against the consumption of nicotine as vapor. Evidence strongly suggests that e-cigarettes are less harmful and can help people quit smoking altogether. (see below)

Folks over at the American Council on Science and Health take note of British supermarket trends that find that as sales of e-cigarettes go up, sales of real cigarettes go down. As ASCH also reports:

It seems highly likely that vaping is slowly but surely replacing smoking. At the same time, the UK's "Smoking Toolkit Study" reported a sudden (over the past 2 years) surge in successful smoking cessation rates there ("quit rates"). In 2011, the quit rate in the UK was 4.6 percent; over the next three years, the rates were 6.2 percent, 6.1 percent, and an amazing 7.5 percent in 2014. As ACSH advisor Dr. Mike Siegel puts it in his well-respected Tobaccoanalysis.Blogspot: Of course, this is merely an ecological analysis. However, the pattern of these trends seems far too striking to be explained alternatively. The working hypothesis, it seems, should be that electronic cigarettes have played a major role in enhancing smoking cessation, both by stimulating quit attempts and improving success in those quit attempts. The irony of this story is that policy makers in the UK wanted a virtual ban on electronic cigarettes, and health groups and many anti-smoking advocates in the U.S. favor policies that would put a huge dent in the growth of the electronic cigarette market (at the expense, of course, of increased tobacco cigarette sales). This is probably the most profound example in my career of public health groups supporting policies that are antithetical to the overall goals of public health.

These insights are bolstered by the findings of many other researchers. For example, based on their review of the evidence comparing the harms of tobacco smoking versus those from vaping e-cigarettes, two University College London epidemiologists in a September, 2014 op-ed in the British Journal of General Practice:

Given that smokers smoke primarily for the nicotine but die primarily from the tar, one might imagine that e-cigarettes would be welcomed as a means to prevent much of the death and suffering caused by cigarettes. For every million smokers who switched to an e-cigarette we could expect a reduction of more than 6000 premature deaths in the UK each year, even in the event that e-cigarette use carries a significant risk of fatal diseases, and users were to continue to use them indefinitely. … Despite alarmist commentaries, studies on the toxicology of the vapour tell us that, while propylene glycol is an irritant and some toxins are present in measurable quantities, the concentrations are in fact very low. Some reviews have bizarrely concluded that we do not know whether e-cigarette use is safer than smoking, ignoring the fact that the vapour contains nothing like the concentrations of carcinogens and toxins as cigarette smoke. In fact, toxin concentrations are almost all well below 1/20th that of cigarette smoke. … This brings us back to the question as to why some individuals and bodies involved in public health are so opposed to e-cigarettes. It may be a concern over how things might turn out in the future given commercial incentives, puritanical ethics, distaste for any industry profiting from a psychoactive drug, inappropriate application of a medical rather than a public health model, or even just a gut feeling that e-cigarettes are bad. Whatever the reasons, it is important that interpretation of the evidence and communication with policy makers and the public is not distorted by a priori judgements.

In the December 9, 2014 issue of the journal BMC Medicine, another researcher from the Wolfson Institute for Preventive Medicine points out:

Although there is no doubt that smokers switching to electronic cigarettes (EC) substantially reduce the risk to their health, some tobacco control activists and health organisations discourage smokers from using EC and lobby policy makers to reduce EC use by draconian regulation. The hostility to EC may be related to a moral belief that nicotine use should be eradicated rather than allowed to morph into a relatively harmless activity. If EC are allowed to compete with cigarettes and develop further, smoking is likely to all but disappear. Discouraging smokers from making the switch and reducing EC competitiveness with cigarettes by unwarranted regulation will delay this opportunity or squander it altogether. In fact, there is now sufficient evidence available for health professionals to recommend to smokers who cannot stop smoking with existing treatments or do not want to do so, to try several types of e-cigarettes to see if they can find one meeting their needs.

By opposing e-cigarettes, anti-tobacco activists are very likely killing the people they claim they want to help.