I know plenty of germophobes. By contrast to, say, twenty years ago, it's now common to find disposable toilet seat covers, hands free taps, soap and towel dispensers at the (recently) doorless airport washrooms. In one of my one man shows, I polled the audience as to how many of them pressed the lever to flush the toilet in a public washroom with something other than their bare hand. About half of them consistently said they did, every performance, everywhere I went.

Well, good luck, germophobes.

According to Dr. Charles P. Gerba of the University of Arizona, your toilet seat is likely to be the cleanest surface in your house, since it's wiped down with disinfectant more often than anything else is. Although if you leave the lid up when you flush, billions of microbes spew into the air each time. As Bill Bryson describes it in his book At Home: "Many stay in the air, floating like tiny soap bubbles, waiting to be inhaled, for up to two hours; others settle on things like your toothbrush."

Your house's filthiest surface: the kitchen sink. If you cook with commercially processed ground beef there's more fecal bacteria in your sink than in your toilet. Quoted in Fast Food Nation, Gerba said "You'd be better off eating a carrot stick that fell in your toilet than one that fell in your sink."

The dirtiest object your house: the kitchen washcloth. Says Bryson: "Most kitchen cloths are drenched in bacteria, and using them to wipe counters (or plates or breadboards or greasy chins or any other surface) merely transfers microbes from one place to another, affording them new chances to breed and proliferate." Barbara Ehrenreich found out the cleaning service ("The Maids") she worked for to research minimum wage jobs for her book Nickel and Dimed: On (Not) Getting By in America, performed a similar microbe spreading service. They were instructed to "spray a white rag with Windex and place it in the left pocket of your green apron. Another rag, sprayed with disinfectant, goes into the middle pocket, and a yellow rag bearing wood polish in the right-hand pocket. A dry rag, for buffing surfaces, occupies the right-hand pocket of your slacks. Shiny surfaces get Windexed, wood gets wood polish, and everything else is wiped dust-free with disinfectant." Ehrenreich later related this technique to two cleaning experts who let her know that her disinfectant soaked rag would have lost its efficacy with each wipe. All she and the other cleaners were really doing was spreading the dirt around.

Donald Trump is famously germophobic, preferring a staid Japanese bow as a greeting to a handshake. In an episode of Penn & Teller: Bullshit!, the two magician/comedian/debunkers found more filth on their test subjects' hands than on their behinds, leading them to conclude it'd be more sanitary if our standard greeting was to rub bare asses.

Ever fly? In his book The Commitment, sex columnist Dan Savage, refers to the "filth that coats absolutely everything inside an airplane's cabin," saying: "One study of airline cleanliness found fecal matter on every single surface tested; every seatback, doorknob, blanket, pillow, and overhead compartment latch had human excrement on it. Think about that the next time you unlatch your tray table or contemplate hitting on a cute flight attendant."

Ever go out to eat? Don't, if you're worried about cleanliness. In Fast Food Nation, Eric Schlosser describes how undercover investigations by an LA TV station videotaped restaurant workers "sneezing into their hands while preparing food, licking salad dressing off their fingers, picking their noses, and flicking their cigarettes into meals about to be served." It gets far worse if you look into fast food joints.

In May of 2000, three teenage employees at a Burger King in Scottsville, New York, were arrested for putting spit, urine, and cleaning products such as Easy-Off Oven Cleaner and Comet with Bleach into the food. They had allegedly tampered with Burger King food for eight months and it was served to thousands of customers, until a fellow employee informed the management.

The teenage fast food workers I met in Colorado Springs, Colorado, told me other horror stories. The safety of the food seemed to be determined more by the personality of the manager on duty than by the written policies of the chain. Many workers would not eat anything at their restaurant unless they'd made it themselves. A Taco Bell employee said that food dropped on the floor was often picked up and served. An Arby's employee told me that one kitchen worker never washed his hands at work after doing engine repairs on his car. And several employees at the same McDonald's restaurant in Colorado Springs independently provided details about a cockroach infestation in the milk-shake machine and about armies of mice that urinated and defecated on hamburger rolls left out to thaw in the kitchen every night.

Bryson adds a story of a Florida middle school student who measured water quality in her local fast food restaurants' soft drink ice vs their toilet water. In a whopping 70 percent of cases, the toilet water was cleaner.

Ever been a dinner guest at a couple's home? What do you think the odds are they've had sex on the couch where you're sitting. Or the chair. Or on the table, or against the counters. Do you think they sprayed it with disinfectant right afterward?

But your body is no stranger to microbes and bacteria. Bryson says "Your skin alone is home to about a trillion bacteria. Inside you are many thousands of trillions more, many of them engaged in necessary and helpful tasks like breaking down food in the gut. Altogether you hold about a hundred quadrillion bacterial cells in your body. If you took them out and put them in a pile, they would weigh about four pounds." The National Geographic episode The Invisible World points out that at any given moment, there are about as many creatures living on you as there are people on the earth, no matter how often and how thoroughly you wash.

So what can you do? Embrace germs, according to George Carlin:

What do you think you have an immune system for? It's for killing germs. But it needs practice. It needs germs to practice on. So if you kill all the germs around you and live a completely sterile life, then when germs do come along, you're not going to be prepared.

Let me tell you a true story about immunization. when I was a little boy in New York City in the 1940s, we swam in the Hudson River. And it was filled with raw sewage. Okay? We swam in raw sewage! You know, to cool off.

At that time the big fear was polio; thousands of kids died from polio every year. But you know somethin'? In my neighbourhood no one ever got polio. No one. Ever! You know why? Because we swam in raw sewage! It strengthened our immune systems. The polio never had a prayer; we were tempered in raw shit!

So personally, I never take any special precautions against germs. I don't shy away from people who sneeze and cough, I don't wipe off the telephone, I don't cover the toilet seat, and if I drop food on the floor, I pick it up and eat it. Even if I'm at a sidewalk cafe. In Calcutta. The poor section. On New Year's morning during a soccer riot.

Of course, Carlin died at 70 of an infection he got from eating a carrot that had fallen into his kitchen sink. No. Heart failure.

But have I eaten from the loaf of delicious home-made bread that fell on the kitchen floor the other day? I asked the great Greek chorus of Facebook what I should do, and twenty or so people chimed in, vociferously mocking my porcelain princess nature in hesitating at all, telling me to eat it.

Hey, what happened to all the germophobes?