Saturday, October 10, 2009

The Precautionary Principle Is Not The Answer




“Better safe than sorry,” is a well known aphorism because it contains a lot of sense. The precautionary principle allures us with words that sound similar to common-sense precaution. 
Unfortunately, the principle is a both a shape shifter and a chameleon. The term can shift in meaning to support whatever side one wishes to take on an issue. Worse, the principle appears to—but does not—provide us guidance in dealing with uncertain risk. The principle appears effective only because it compares uncertain risk against implicit zero risk for the status quo. 
In the real world, difficult questions of uncertain risk are problems of benefits versus risks, risks versus risks, and benefits and risks versus alternative benefits and risks. The principle is at its worst in guiding us with risk versus risk situations. The precautionary principle advises us to avoid both risks—but how do both take action and inaction at the same time? Or as Michael Crichton said, “The precautionary principle properly applied forbids the precautionary principle. It is self-contradictory.”
Ronald L. Doering has written a pithy essay, “The Precautionary Principle Is Not The Answer,” that uses excellent examples to illustrate the fundamental flaw with the using the precautionary principle as an approach to deal with risk versus risk:
If the hazard of DDT, for example, were a possible threat to the environment, then the application of the precautionary principle would be to ban the product until the science is clearer. If the hazard is malaria causing mosquitoes and the million persons killed (and the 300 million made seriously ill) by malaria each year then wouldn’t the principle support taking action to continue to use the product until the science is more certain? A principle that is this malleable cannot be a reliable guide to decision making, but it is still often used as a justification for a decision taken for other reasons.
Or consider the fortification of enriched flour with folic acid. The risk of neural tube defects (major birth defects of the brain and spine, such as spina bifida) can be reduced by 50-70 percent if women receive folic acid supplementation starting three months before becoming pregnant. An estimated 1,000 more babies are born healthy each year because of mandatory fortification of foods with folic acid in the US. 
On the other hand, there are unknown risks of folate fortification for the majority of consumers who receive no benefit from increased folate. A recent study showed there might be a link between high intakes of folic acid and possible increased risk for colon cancer.
The precautionary principle supports mandatory fortification with folate. Rather than take the risk of inaction while the science is uncertain about the risks of fortification, it is better to be safe and prevent a thousand newborns a year from major birth defects. Accordingly, the US in 1994 and Canada in 1998 mandated fortification of certain flours and breads. “Applying the same principle, Britain and Ireland declined to require mandatory fortification.”

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