How do restroom hand dryers end up filled with bacteria that is blown onto your clean hands?

Question

I don’t understand how the machines collect bacteria. Is it because of the humidity? Confined air in the space?

In: Biology

Answer 1

A mix of what mentioned and the fact that your assuming you’re hands are perfectly free of bacteria and clean when you wash them.

First, any surface is going to have some kind of bacteria on it unless it is regularly sterilized, so unless that’s happening the hand dryer isn’t perfectly clean itself.

Next is yea that some room conditions (like humidity) can be good for bacteria growth.

But really the big one is that unless you do a super deep long clean, you hands arent perfectly bacteria free. And the bacteria that’s left on your hands can be blown off you hands and circulated around the room, possibly to another person.

Studies done for hospitals found that air dryers spread bacteria way more than paper hand towels, which is why hospitals typically use paper towels and not air dryers.