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The reactionary principle
A commentary last year in the journal Occupational and Environmental Medicine urged adoption of the well-known “precautionary principle”—that when a substance or technology is suspected of being harmful, “precautionary measures should be taken even if some cause-and-effect relationships are not fully established scientifically.” Instead, said the article, current research operates under the “reactionary principle.” The author explained that under this system, anyone is free to introduce a new hazard into the environment, and governments must wait until an overwhelming body of evidence is accumulated before intervening. Each new regulatory action is challenged with the objective of slowing down or stopping public oversight. We can see the reactionary principle in action in the unconscionable delays in regulating a long list of hazards whose risks were clear long before effective actions were taken to control them: asbestos, benzene, dioxins, and PCBs. While these are “old” hazards, a reactionary approach is evident as well in many current controversies in our field, including the potential health risks from hexavalent chromium, artificial butter flavoring, and the antimicrobial agent triclosan.
Even if, displaying full trust in the safety of antimicrobials, you could manage to eliminate those 99.9 percent of bacteria and viruses from your doorknobs, your computer keyboard, and the change in your pocket, you would still be carrying in and on yourself a community of microorganisms outnumbering—10 times over—the cells in your own body. Almost all of those creatures are either neutral or beneficial to you.
But the modern arsenal of purifying products, including not only disinfectants but also regular detergents, medications, vegetable washes, ozone blowers, ultraviolet gizmos, filtered and bottled drinking water, air-conditioning, and year-round-sealed windows may be reducing contact between people—especially children—and organisms with which we’ve evolved and which our bodies need for healthy development. Not being “smart weapons,” antimicrobial products can wreak collateral damage on harmless and friendly microbes.
The now 30-year-old “hygiene hypothesis” says that skyrocketing rates of allergy and asthma in Western societies may result from human immune systems being driven haywire by excessively sterile home environments. It’s a hard thing to demonstrate, the biological mechanisms are highly complex, and there are still plenty of doubters, but patterns continue to fit fairly well.
“We have to find a healthy balance in hygiene,” says Allison Aiello. “For example, right now on your hands there are millions of beneficial Staphylococcus bacteria that help maintain the health of your skin.” In fact, in her work she has seen disease-conscious people scrub their hands too enthusiastically, creating dry-skin cracks that other, more dangerous bacterial species can infect.
To Dr. Paul Fey, putting antimicrobial chemicals into cleaners and toys is “just crazy—the only reason it’s there is to keep parents from worrying.” But, he thinks, maybe it’s the products themselves they should be worrying about: “This constant search for a totally sterile environment may be hurting our health, and especially