Map of life expectancy at birth from Global Education Project.

Wednesday, August 20, 2008

Ewwww, germs!

My mother once scolded me for telling my younger sister that she had millions of microscopic animals living on her skin. But of course I was just telling the truth, more or less -- technically the term "animals" is currently reserved for one of the two kingdoms of the eukaryotes, and my sister's inhabitants are mostly (though not exclusively) prokaryotes, but still . . .

In fact, inside and outside, we have about 10 bacteria and archaea for every one of our own 50 trillion human cells. So we aren't just organisms, we are each of us entire ecosystems. Recent analyses -- discussed by Robert Dorit in American Scientist (I'm starting you on page three so you can skip the mystical BS at the beginning) -- find that each of our body parts, from the crook of the elbow to the crack of the ass, the stomach to the nostril, constitutes a unique habitat with its own, specific ecosystem and particular complex of microorganisms.

The fact is that 99.99% of the microbes on and in our bodies, and in our environments, are not just harmless, not just beneficial, but essential. In innumerable ways, they make our own lives possible. That's why I am more and more annoyed -- nay outraged -- by the ever growing barrage of advertising for products intended to sterilize our homes, our clothing, and our children. Spraying bactericides all over your bathroom and your kitchen will not, repeat not, protect you from disease.

If anything, such practices will increase your chances of getting sick. One of the most common adverse effects of taking antibiotics is, get this, opportunistic infection. Take amoxycillin for your earache,wipe out the natural flora in your throat, and you get thrush. I'm inclined to think that something comparable can happen with topical bactericides on your skin or in your house. Pathogenic organisms are continually reintroduced from contaminated food, and infected people (whether or not they have a clinically observable illness). A healthy microbiotic environment crowds them out. We control them specifically by the way we handle food -- washing the knife and cutting board, and our hands, after handling raw meat, for example. If we try sterilize the rest of the environment, we just give them room to move in.

I wish we could put a stop to the shameless promotion of these useless and even harmful products, but you know, it's a free country. Anyway, you read it here: wash with soap and water, and leave it at that. Germs are your friends.

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