Don’t Judge a Hand Dryer by a Petri Dish
This awesome, I mean disgusting Petri dish is covered in germs collected inside the Dyson hand dryer. The photo has garnered a lot of people on Facebook, but that doesn’t mean hand dryers should be banned.
Nicole Ward told The New York Times that she did this experiment for her microbiology class. (I reached out to Ward for more details, but she didn’t respond until posting.) This is a pretty classic laboratory experiment: Open a petri dish almost anywhere in the world and you have some kind of germs that will grow when you incubate them. at high temperatures in the laboratory.
But that doesn’t mean there is something wrong with the hand dryer. “Your skin is covered with germs, but that doesn’t stop you from holding hands,” says Mark O. Martin , a microbiologist at Puget Sound University. “I can’t tell you how much you have in your mouth, but you still kiss people. We swim in a sea of germs all the time, and that’s okay. “
The species on Ward’s plate look like they might be mushrooms, which Martin says makes sense because many fungal microbes produce spores that survive in dry air. Ward says she used SabDex agar plates, which are listed on one supplier’s website as “for growing yeast and mold.” Different types of plates show different microbes, and some microbes do not grow on the plate at all.
If you really want to understand if hand dryers expose harmful germs, you will need to identify those germs and compare what you find with what you find on paper towels and their dispensers and what is simply in the air. … bathroom. After all, when flushing, toilets spray germs, and we kick dust off the floor as we walk. Wherever we go, we are all surrounded by a cloud of germs , so if you want to avoid germs, you will have to avoid people as well.
But don’t. Not all germs spread disease. “Pathogens are kind of juvenile offenders in the microbial world,” Martin says. “There are very few of them, but they get all the press.”