I hate to be the bearer of bad news but I recently reviewed some interesting facts about those hand drying machines at airports and the ones in church and restaurant bathrooms. It appears that drying with these devices, after you have washed, may be contaminating your hands with poop. Yes you read that right. Your wet hands could be exposed to fecal material from what is known as “toilet plume.”
An article in Applied and Environmental Microbiology showed that exposing sterile plates or petri dishes for just 30 seconds to the blowing hot air from those hand dryers caused the growth of bacteria, bacteria that is usually found in your intestines, in your poop. While the plates that were exposed to normal bathroom air had about one bacterial colony present, the samples that were exposed to 30 seconds of hand dryer air had 18 to 60 bacterial colonies per plate. Most of the bacteria that grew on those dishes were not harmful. However some of them were dangerous and could cause severe illness.
Now, Don’t Freak Out.
Bacteria are everywhere. You would be amazed as to how much bacteria, fungus, viruses and spores you come in contact with on a daily basis. The research here seems to indicate that in the bathroom there is a higher concentration of these organisms.
Now you may be asking how did this happen? Well we know that fecal material containing bacteria shoots into the air when a lidless toilet flushes. This phenomenon is known as “toilet plume.” Studies have shown that when someone flushes an open toilet, little bits of poop and bacteria can be thrown as high as 15 feet into the air. The hand dryer then sucks up the contaminated air, warms it, and when you dry your hands under the machine, your hands now become contaminated.
What was not resolved was the question of whether the blowing of air on your hands provided more exposure to the already contaminated air or that the blowers themselves were the “reservoir “ for bacteria.
Wash Your Hands, Of Course, But Dry Differently
You may now be in agreement that there is a lot of bacteria in bathrooms. Knowing this I have decided to officially not use any of those blowing devices again. People who have weakened immune systems, like seniors, should follow my example and avoid them also. Paper towels are a a good alternative. I am even trying to hold my breath for as long as I can when entering and exiting any bathroom.
Some good news was forthcoming at the end of the article. The researchers showed that retrofitting hand dryers with HEPA air filters reduced bacterial colonies four times over.
So there you have it. If you see me waving my hands in the air outside of a bathroom, it is because I’m drying them. There was a hand dryer in the bathroom but no paper towels.