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A precautionary tale

Posted by on March 28, 2014

Ahead of the Society of Biology’s next Policy Lates event on the precautionary principle, Tracey Brown of Sense About Science gives her view on some of the issues surrounding the principle and its application.

What would you say if I suggested farmers start using a compound that could mess with your hormones in order to improve crop yields? I’ve conducted some pretty strict testing which indicates that it is safe but I can’t be sure; I haven’t got evidence that shows it is completely safe for you to be exposed to it over many years – I may never have evidence to put any hypothetical harm beyond doubt.

But that doesn’t matter, because the answer’s no anyway, right? We’re not going to take the chance. Now, how about if I told you that this compound would replace one that is persistent in waterways and which is being sprayed with increasing frequency because its effectiveness has dropped as the fungus it kills has evolved resistance? (All that extra spraying demonstrably harming ladybirds and other beneficial insects.) And, by the way, when I say mess with your hormones, I mean in doses that you’ll never be exposed to. In fact if you want to go into the detail a bit, what I really mean is that it has been shown to interact with the endocrine system, as many things you encounter on a daily basis do – including much of your food – and there’s no evidence that this particular interaction is harmful.

If you’re still not sure, you might also want to consider that if you don’t want my compound, you’ll be obliged to turn down two others that work in similar ways. The fungus’ resistance to the old compounds in use is developing quickly and will continue to do so with none of these new compounds available to rotate. The resulting stress on the plants from intensive use, and the increasing frequency of fungus damage to the crop, means the price of the produce will increase by half as much again. People on low incomes won’t be able to afford it, unless cheaper imports can be found.

Well you might still tell me to take my compound elsewhere (which I’ll do and which might, as it happens, still lead to small amounts of it being present in your diet as the produce grown with it is imported into your market to address the lower yielding and less affordable local growing you’re stuck with – although that might just be a humbug argument from me as a sore innovator). You would be able to declare that you’ve done a good thing by shutting off the hypothetical potential for harm from a new compound. Job done. But whether or not you still conclude my compound’s a non-starter – which you must be free to do – you see the point here.

As we move out from the narrow presentation we started with to look at the context, to consider the relative risks of different options and the unintended consequences of closing down some of them, to take in the overall picture of different kinds of risks – resistance, food poverty, continuing with current practices … we are faced with a more complex decision and one that invites greater responsibility. Responsibility for problems now and problems that might arise in the future. It is the effect of the precautionary principle in limiting that responsibility which we must discuss.

Tracey Brown is managing director of Sense About Science.

3 Responses to A precautionary tale

  1. Rick Stafford

    I’d agree with all of this, but these examples are trade offs. If there was a risk of using a chemical, but no real need for it, you shouldn’t use it. Alternatively, perhaps we should reduce the amount of fish we catch, even though the science isn’t perfect in predicting stock size. The precautionary principle is sound, just that in the real world, the question can be more complex…

  2. Drew Rae

    The trouble is overstatement of the precautionary principle so that it merges with the Delany principle. If you hadn’t done some testing, you couldn’t use the absence of evidence of danger as evidence of safety. Having done reasonable attempts to assess the risk the precautionary principle no longer applies.

    Now the question is purely whether the remaining risk (some of which comes from scientific uncertainty) is acceptable. Rejecting an option because there is any risk whatsoever is not what the precautionary principle is about at all.

  3. John Elder

    The biggest problem I see with such “precautionary principle” approaches is that when they are applied by the general public decisions are largely not made on the basis if reasonable precaution. In the public, hence policy making , sphere decisions are typically made in fear and hysteria based on ignorance of valid facts and principles, false correlations, misrepresented and false research, vested interest propaganda and public media hype. Simply taking a precautionary approach to potential risk(as in imagined in the absence of real knowledge ) usually results in a chicken little outcome. “When in danger, when in doubt, run in circles, scream and shout”? But lets call it “Precaution”. Human masses want simple answers that result in security. There simply aren’t any available for complex problems.