Hey Doc – what in the world is the Precautionary Principle? Seems I’m hearing about it all the time when people talk about all sorts of things – biotech, new medications, radiation, nuclear energy, and all that. And when I look up what it’s supposed to mean it seems different than how the term’s used a lot of the time. Help!
Yeah – it can get confusing, can’t it? What the Precautionary Principle comes down to is admonishing us to be careful, especially when we’re confronted with something novel and potentially hazardous that we don’t know much about. Take a new medication for example – the Precautionary Principle tells us that we shouldn’t give it to millions of people unless it’s been tested and found to be safe.
Well…that makes sense…and that’s what we do; brand-new medications are tested on laboratory animals and, if they seem to be safe (or safe enough) then they can be tested on small numbers of people, then on larger numbers of people, and then on still more people. Only when those tests show the drug to be safe (or to be less dangerous than the condition the drug is treating) is the drug approved to be prescribed by physicians. Over time, after increased use has given us more years of experience and millions (or billions) more people using it and the medication continues to look safe then it might finally be approved to be sold over-the-counter.
And look at all the times the Precautionary Principle is exercised in this process! Trying a drug on rats protects any person from taking a compound that might end up being toxic, mutagenic, or otherwise dangerous. Trying a drug on a small number of people to see what it does gives us valuable information about its safety without putting more than a relative handful of people at risk. And so forth, at every step of the way – the final precautionary step is requiring that physicians exercise their judgement before a person lacking scientific training and medical knowledge before a patient is permitted to take the drug because, once it’s available to be sold over the counter, anyone can take it for any reason. Of course we want to make sure we understand the drug, its interactions with other medications, its side effects, its efficacy, allergies, and everything else we can know about before we let that happen.
Here’s the thing: There’s nothing in the Precautionary Principle that requires something be 100% safe – that it work every single time and that it have absolutely zero negative side effects – before it can be used. If that was the case chemotherapy drugs, would never have made it past clinical trials – nor would multivitamins, for that matter. Don’t believe me on that last one? Take a look at what they include – selenium is toxic and causes birth defects, cobalt is toxic…for that matter, Vitamins A and D are toxic in high doses. So’s aspirin, for that matter, as well as acetaminophen. If the Precautionary Principle was interpreted as requiring that nothing new be adopted unless it could be shown to have zero risk, we’d be living very different lives in a very different world, with a very different quality of life. And that’s with decisions that are relatively easy – just looking at the risks from a new technology or medication. What about something more nuanced?
I think I’ve mentioned in the past a time when my younger son was having trouble breathing due to an allergic reaction. The Emergency Room doc prescribed an x-ray and the radiology tech started to explain to me the risks my son might face from the radiation he was about to receive.
Let’s pause the story for a moment. We know that radiation can cause cancer and that the reigning paradigm tells us that there’s risk associated with any level of radiation exposure. Wouldn’t the Precautionary Principle tell us to avoid exposing my son to any level of radiation? How could an informed physician recommend exposing my son to this radiation; and for that matter, why in the world would I, a radiation safety professional, let it happen?
When the technician was explaining this to me, she wasn’t covering anything I wasn’t already aware of (not casting any aspersions at all – if the typical person knew about radiation this blog wouldn’t exist!). So I interrupted and asked how long a person could survive without breathing and pointed out that it’d be nice to keep my son alive long enough to find out if there were any long-term health effects in the decades to come. And that’s why both the attending physician and I felt comfortable with a toddler (my toddler!) being exposed to radiation – breathing problems pose a significant risk in the short term while low-level radiation exposure poses only a very, very low (hypothetical) risk a few to several decades in the future. But, then, when it comes to radiation we know a lot about the health effects of radiation exposure – enough to give permission for my son to be x-rayed.
That brings up two things about the Precautionary Principle that many proponents don’t seem to realize:
- We don’t need to know everything there is to know about something in order to know enough to make a decision
- And we can decide to use something, even if it causes some risk.
Something else to keep in mind is the risk of failing to take action, even if there’s a risk that’s slightly less-understood. Consider the famine in Zimbabwe and Zambia in 2003. With nearly 3 million of his citizens facing starvation, the President of Zambia, Levy Mwanawasa informed BBC reporters that “We would rather starve than get something toxic.” With that, thousands of tons of grain were locked away in warehouses, out of reach of the starving. The “toxin” to which Mwanawasa referred was genetically modified grain—grain that was being served in the United State and Europe with no apparent health effects and, in fact, grain that was available at stores in Zambia as grain imported from South Africa.
Whether motivated by political factors or by a genuine fear of the grain, Mwanawasa’s decision to spurn freely offered food did nothing to help combat famine. It also infuriated those trying to help his country. The United States ambassador to the UN food agencies, Tony Hall, angrily attacked this decision, saying “People that deny food to their people, that are in fact starving people to death, should be helped responsible…for the highest crimes against humanity, in the highest courts in the world.” Mwanawasa was adamant—his people should go hungry and even starve to death rather than to be exposed to the potential dangers of genetically modified food. And I simply have to ask myself, does it make sense to let people starve to death today to prevent the hypothetical risk of adverse health effects at an indeterminate time in the future? Or, as with my son, might it make sense to feed them and to keep them alive long enough to find out if the biotech grain causes long-term issues?
So let’s think about radiation with regards to the Precautionary Principle; do we know everything there is to know about the health effects of radiation? Well – no – we went over that already. Among many things, we don’t know exactly what risk one might face from a dose from a single medical x-ray. But I would argue that we don’t need to know everything in order to know enough to make medical decisions – is the risk from the radiation greater or less than the risk from not having the diagnostic information the radiation exposure will reveal? And what poses the greatest risk today and in the near future? We might not know everything – but we do know enough, which is why there are so few complaints about using medical radiation.
Well (I hear…someone…say) that’s medical radiation, but we know that medical radiation saves lives every year – millions upon millions of them. What about nuclear energy? To which I’d point out that energy – rather, access to energy – saves lives too. Energy is so important to medicine that it’s pretty standard for hospitals to have an emergency electrical generator. Street lights and stop lights save lives that would otherwise be lost in traffic accidents; radars help keep planes from colliding; computers run an increasing number and variety of our safety systems; air conditioning and heating keep people alive in extreme temperatures; communications networks make it possible for those in need to call for help, and on and on and on. By and large, people in places with reliable energy have longer, healthier, more productive lives than those without. We must consider not only the risk from using a technology, but also the risk of denying ourselves that technology – the lives that won’t be saved or enriched. If I choose, for example, to power my home by burning coal to run a small electrical generator then I’m accepting the risk of my home burning down, the risk of carbon monoxide seeping into my home, the risk of inhaling coal dust and fly ash, the added cost and effort of running and maintaining my own power system, and so forth.
There’s been ten of thousands of pages written to add up the pros and cons of nuclear energy versus other forms – comparing the deaths, the radiation exposure, the tons of CO2 emitted, and scads of other metrics per TW-hr of energy produced – and I can neither add to nor meaningfully summarize all of that here. What I would suggest, however, is that the next time you hear someone refer to the Precautionary Principle, to ask yourself – to ask them if you can – how many things there are in the world about which we have perfect knowledge…and since that number is zero (if only due to Heisenberg’s Uncertainty Principle), how much knowledge do they feel is required before they feel the Precautionary Principle has been satisfied. Then, perhaps, ask them if, when applying the principle, they also consider the risks from denying ourselves the benefits of…whatever it is they’re concerned about. You might not change their mind – but at least you’ll have an idea of the amount of thought they’ve put into their rejection. And then, decide for yourself the amount of credence you give their ideas.