Vaping will be banned in smoke-free areas, although 'this is a precautionary measure' as there is no robust evidence of harm from second-hand vapour.Welcome to the carefully considered decision of New Zealand's public health gauleiters. Yes folks, they're going to ban something they know isn't harmful because, y'know, precaution. Just let's be clear about this - every single drug introduced onto the market would need banning under this principle. No clinical trial, no epidemiological analysis, no Cochrane Review, no metanalysis and no research appraisal can eliminate the possibility that, in some way, there might be harm.
So what is it with these public health people? Why do they continue to ignore the self-evident reductions of harm from a liberal attitude to vaping and focus instead on something without evidence of harm - sidestream vapour?
For all its problems, the precautionary principle makes some sense. But its purpose is not to ban everything that has even the slightest prospect of causing harm. The problem is that the way risk managers might make use of precaution is very different from the idea of "better safe than sorry" because the latter is a recipe for preventing innovation and invention on the basis of risk.
The purpose of the Precautionary Principle is to create an impetus to take a decision notwithstanding scientific uncertainty about the nature and extent of the risk, i.e. to avoid 'paralysis by analysis' by removing excuses for inaction on the grounds of scientific uncertainty.That seems clear enough - we act with caution (I'm a conservative why wouldn't I support that idea) but we still act. And we don't let the lack of scientific certainty - proof as us laymen might put it - prevent that action. This is, to the annoyance of some, the driving principle behind many environmental interventions - we're confident that greenhouse gas emissions contribute to changes in climate but we know precious little about the when, why or where of this impact or even how great or small it might be. But because the worst case downside risk - human extinction - is big enough we choose to act on that climate risk.
The problem here is that, while we want action, we don't know what policy choices are effective and what aren't effective resulting in a mish-mash of essentially virtue-driven policies rather than a clear, simple intervention. So, if the reason for climate change is greenhouse gas emission (at least in part), the simple response is a carbon tax but instead we get a bewildering collection of subsidy, sub-optimal investment and bans that don't get to the heart of the problem.
All this is probably fine until we start to apply the idea to areas where the worst case downside risk is not so bad. Obesity is a problem but it's downside risk is a shorter and less comfortable life for the obese and a marginal increase in healthcare costs for society - neither of these are existential. The same goes for most of what passes for public health these days and it results in stupid, "gotta be seen to do something" policies like banning adverts for burgers on bus stops. Worse there's a whole industry of pseudo-science developed to provide succour to these policies - a steady trickle of poorly-framed, badly conducted research studies designed with the ideological purpose of justifying bans, controls and limits in the interests of health.
So focus on the simple - for smoking the two things that worked well to reduce consumption of tobacco, public information and price, have run their course because everyone knows smoking is unhealthy and the price has reached the point where the biggest criminal growth industry is smuggling tobacco. So what's left - especially given further evidence that 'stop smoking service' interventions are expensive and pretty ineffective? We're either got drugs like varencline or vaping. And varencline, for all is effectiveness, carries an actual and demonstrated risk. In contrast vaping really isn't harmful - at least if Public Health England's most recent evidence review is a guide (it would be asking to much, I guess, for PHE to show the same degree of robust review when it comes to alcohol harm or obesity).
So to apply the precautionary principle to policies on vaping in public spaces - "we don't have any evidence it's harmful but, you never know, so we'll ban it" - is to completely misuse that principle. And, in doing this, the idea that vaping is harmful gets set in people's minds - and if a smoker thinks vaping is just as bad and the government bans it in public space then those smokers will carry on with much more harmful smoking. The consequence of precaution isn't safety, it's more harm.