GIGO

Natural Chemicals

Q. When is a chemical not a chemical?
A. When it's "natural".

This seems to be a common perception, and one that is hard to address. I was recently pleased to hear a radio correspondance school science segment run a short skit on this perception and how it can be misleading.

In it, a news announcer was outlining all the dreadful things that had happened in the past week -- a chemical leak, chemical residues found in fruit, and so forth. He was interrupted by a rather indignant gentleman objecting to the use of the term "chemical" as if it automatically meant something environmentally unfriendly and potentially dangerous.

They went on to discuss what a "chemical" actually was and touched briefly on the distinction, if such there is, between natural substances and chemicals.

The distinction I've encountered most commonly seems to rest on the rather tenuous idea that if it's something produced artificially, then it's a chemical, whereas something produced without human intervention is not. Thus a friend of mine sprinkles kelp on her vegetables in the firm belief that the "natural" iodine contained in the dried, ground seaweed is somehow better than the "chemical" iodine artificially introduced in iodised salt.

It is obvious to a chemist that the two are exactly the same. However, we're not dealing with chemistry here, but the worries and concerns of a world where increasing stress is being laid, albeit somewhat shakily, on the value of the natural over the artificial.

In response to consumer demands for pesticide-free produce, fruit and vegetable researchers are producing new varieties that have a built-in "natural" range of pesticides, fungicides and other toxins. Occasionally they run into the problem that their breeding programmes are so successful, the plants can no longer be eaten because the "natural" poisons exist at dangerous levels. Unlike the often intense scrutiny that "artificial" chemicals get, these "natural" toxins, poisons and, yes, chemicals, tend to be unmonitored and uncontrolled.

There are many implications in the natural versus chemical debate. I have often wondered how much the resistance to 1080 poisoning would drop were scientists to stress its "natural" origin in Australian plants and to call it by a less chemical-sounding name.

A soil scientist I know maintains that the practice of automatically equating "natural" with "good" because Nature is always benign is a charming legend, on a par with Santa Claus. While that may be so, it is a legend which is having an increasingly important effect on everyone from producer boards to manufacturers, as they strive for the "natural", clean image so desirable these days.

They should be encouraged to make sure that their enthusiasm for this form of marketing does not compound the erroneous impression that a natural product, of necessity, means a chemical-free product.

Vicki Hyde is the editor of New Zealand Science Monthly.