Happy International Year of Chemistry. We hope things go well with your effort to increase public appreciation of chemistry and increase the interest of young people in chemistry and generate enthusiasm for the creative future of chemistry.

Fat chance that’s going to get us to relax, though. Sure we know that chemistry has produced some pretty cool stuff, like DVDs and DNA, and when you mix vinegar and baking soda you can make a volcano, which is really cool. But let’s face it. Maybe when you hear "chemicals", you think of the Periodic Table or how hydrogen bonds work. When we hear "chemicals" we think death, harm, cancer, birth defects, danger, pain, poison, pollution, hazardous waste, Love Canal, Bhopal. Oh, joy!

So, happy IYC and all. But forgive us if hearing a word like "chemicals" doesn’t get us in the mood to celebrate or appreciate or enthuse. We know everything is made of chemicals and that without chemicals, life would be impossible. But just keep that stuff away from us, okay? It’s dangerous.


The Public

It’s not hard to understand why the world’s academic and industrial chemists would have asked UNESCO to give its official imprimatur to the International Year of Chemistry. Chemistry has taken its lumps over the past few decades. Well, maybe not the science itself. But certainly chemicals, and the chemical industry, which have produced wondrous benefits to be sure, but have also given us so many things to worry about that they have engendered their own place in the lexicon of fear: chemophobia. And their own body of law: toxic torts. And their own form of agriculture: organic (which initially simply meant chemical - as in pesticide - free). In fact the whole modern environmental movement was initially, and largely remains, a response to fear of chemicals.

It is hardly in the spirit of the International Year of Chemistry to say this, but such fear makes sense. Not, certainly, in terms of the actual physical risk from chemicals which, while real and in some cases severe, is often not commensurate with how worried people are. But the fear does makes sense in the context of the psychology of how humans perceive and respond to risk. And those academics and chemists and scientists who scorn these fears as irrational, are themselves guilty of the same thing, selectively and irrationally denying what the sciences of risk perception tell us to see things not as they are, but how they would like to see them.

While neuroscience and psychology and sociology may not be among the sciences in which chemists are trained, these fields have studied the psychology of risk perception, rigorously, for decades. Work from those disciplines, supported by the overwhelming reality of evidence from the real world (Exhibit A –Chemophobia), establishes beyond any question that while there may be some basic facts about "risk" that we can know, the perception of risk by individuals is subjective: an affective mix of the facts and how those facts feel.

The findings from this rich body of research make incontrovertible that risk perception is not, and can never be, a purely fact-based process. And no flag-waving International Year of Chemistry will make it so. Here are just a few of those findings, pertinent to Chemophobia:

- Risks that are human-made are scarier than those which are natural.

- Risks we can’t detect with our own senses, or that we can’t understand, are scarier.

- Risks that lead to particular painful results - cancer - are scarier.

- Risks imposed on us - by industrial chemicals in our air and water and food – are scarier than risks we take voluntarily.

- Risks created by industries whose behaviors have taught us not to trust them, are scarier.

In addition to these emotional inputs, people use several heuristics and biases – mental shortcuts – to make judgments about things under conditions which Hebert Simon called "bounded rationality"; the real life limitations of not having all the facts, or all the time to get all the facts, or all the intellect and training necessary to understand the facts, before we have to decide, quickly, moment-to-moment. These largely subconscious information processing tools also contribute to feelings that sometimes don’t match the hard cold facts.

- ‘Representativeness’ helps us make sense of partial information by comparing the clues against patterns of what we already know (we assess the first few hints about some new chemical risk against what we already know about chemical risk…dangerous, cancer, birth defects, untrustworthy industry, etc.).

- Loss Aversion. Humans are inherently precautionary, so in a choice between benefits and risks, the risks carry more weight. (Which seems to carry more weight to you: flexible plastic bottles or reduced sperm count, spotless apples or liver cancer?)

- ‘Availability’ – the more readily and powerfully something comes to mind, the more powerfully it fuels our self-protective fears. (Bhopal, Love Canal, Seveso, Times Beach, DDT, thalidomide, DES babies…need I go on?)

And finally, for the rationalists who still dismiss the mountains of evidence about the instinctive subconscious tools that shape our decisions and judgments, here’s the topper. Neuroscience (a "hard" science) has found that the wiring and chemistry of the brain guarantees that we react to potential risks with instinct and feelings first, and cognitive reasoning second. And after the initial stimulus, in the ongoing dynamic of how the brain figures out what to be afraid of, feelings carry more influence than rational conscious thought. It is inescapable neural reality that we can not divorce our subconscious affective instincts from conscious reason, and that between the two, feelings can more easily overcome reason than the other way around.

What all this evidence means is that it is no more rational to call people irrational for this risk response than it is to call them irrational for not having eyes in the back of their head or four legs. This is the intrinsic reality of how we have evolved to perceive and respond to danger. It may not be the sharpest knife in the drawer for cutting through complicated modern risks with all their tradeoffs and messy but important details. But at this point in our evolution, it’s how we do it.

So rather than ignoring this reality, and dissing it as dumb, and trying to change people’s minds by recognizing only the benefits of modern chemistry, perhaps the International Year of Chemistry might also be a good time for chemists to show a little respect for the other sciences which have revealed a lot about why "chemicals" = "scary".

That, in turn, might produce a bit more respect for people’s fears, as irrational as they seem. And that, in the end, might make for a more open and honest consideration of the real risks that come along with modern chemistry’s fabulous benefits…which can help make the conversation about risks more of a conversation and less of a battle…which in the end might do far more to help people keep their understandable worries about modern chemistry in perspective.

About the Author: David Ropeik is an Instructor at the Harvard Extension School and author of How Risky Is It, Really? Why Our Fears Don't Always Match the Facts.


The views expressed are those of the author and are not necessarily those of Scientific American.