If you watch advertisements, or cruise the supermarket shelves, you can’t fail to notice that everything is anti-bacterial now, as if common household bacteria have suddenly become as exotic and deadly and Ebola.

It’s a great marketing coup, but potentially a dangerous one. In our enthusiasm for all things anti-bacterial we are, thanks to the law of natural selection, breeding even more deadly forms of bacteria that laugh at our anti-bacterial handsoap. Just as with the overuse of pesticides and antibiotics, the overuse of anti-bacterial products assures that only the fittest bacteria survive, thereby selecting out ever more virulent strains with each new generation.

For this reason, in 2000, the American Medical Association recommended that the practice of common antimicrobials to household products be discontinued. Of course, no one listened to them.

And in our quest for antiseptic environments we lose the low-key exposures to both friendly and not-so-friendly bacteria that keep our immune systems in good working order. This is not to say we should wallow in filth, but it may well be healthier to wallow in a mud hole than in a vat of antiseptic gel.