How sanitary is money?

Dear Matt:

How sanitary is the money that passes through our hands every day? I recently got some change back at the store, and one bill appeared to be spattered with blood. I was reminded of Frank Herbert's novel The White Plague, in which a deadly epidemic is spread via the circulation of money. Are there any government safeguards against such a scenario?

-- Mark Schimming, Oceanside

Guess the feds haven't read that book yet. But real-live terrorists usually aren't so patient; they have quicker ways of getting us than waiting for a dollar bill to make its way across the country. In fact money is pretty filthy, according to a bunch of recent studies. Bacteria, fungi, yeasts...worse than the proverbial toilet seat, in most cases, though not all of them will make you sick. And unless you lick lots of cash or rub it on an open wound or cram it up your nose, even the harmful ones probably won't get past the barrier of your skin. Also, since cash is usually dry, many microbes can't live very long in the desert of a ten-dollar bill. Many of the tests on cash did grow junk in petri dishes, but in such small quantities that a single bill doesn't contain enough bits to make you sick. All in all, money is funky but generally non-lethal.

The FBI says your cash is much more likely to be full of cocaine than E. coli. Their chemists have tested bills all over the place and claim to have found dope embedded in the paper fibers of most, especially ones. When dope-contaminated bills are sent through banks' counting machines, cocaine gets in the mechanism and spreads the crystals to neighboring bills. The quantities found are even too small for drug-sniffing dogs to detect, so there's reason number two not to shove a twenty up your nose.