One of my pet peeves as a microbiologist: stories in the media that consist of “OMG we found bacteria on your keyboard/dishwasher/cellphone/toys/books/doorknobs/vacuum cleaner/gas pump handle.” Bonus points if the study isn't actually published anywhere, and double bonus points if the “research” was funded by a company that makes cleaning products.
There are three major problems with this kind of story:
First, bacteria are everywhere. It’s no shocker that anyone with a Q-tip and a Petri dish can find them on your cellphone. Sure, cellphones are covered in bacteria … because every inch of our bodies is also covered in bacteria. Especially our hands.
Second, most of these stories focus on “dangerous” bacteria without actually measuring any such thing. For example, most E.coli are perfectly fine. In fact, some are essential to have a healthy digestive tract. True, some strains (such as O157:H7) are bad news. But simply saying “E.coli” doesn't provide very useful information. It’s akin to describing a burglar as “human.”
Third, even if there are genuine pathogens (which by the way represent only a tiny, tiny fraction of bacteria in the world) on some of these household items, that doesn’t equate to an actual health risk.
Recently I came across a perfect example of how bacteria are misrepresented in an article entitled, “Smartphones and Tablets Harbour More Germs Than Toilet Seats.”
Which leads perfectly into another pet peeve and the motivation behind this piece.
Contrary to popular belief, toilet seats are quite clean! They are of no use as a metric of how many bacteria you might find on a surface. Why is that, you might ask? Two reasons. One is that there just aren’t as many microbes on the part of your body that actually sits on the toilet seat: Your thighs have many fewer bacteria than, say, your hands. Additionally, we clean toilet seats. Often. With bleach.
So I’m just going to say it: I would lick a toilet seat before I would lick a cellphone. Though neither one is very likely to cause any harm.