Environmental Health Officer here... I had a classmate who did a study on this, specifically the Dyson-type where you stick your hands in downwards.

Next time, take a look at what's there in the 2mm gap on the bottom inside where the water, etc. collects, and where the forced air blows all that material. Remember to not breathe.

There's a reason why we direct food businesses to use paper towels in the kitchen, not hand dryers. Also, because ain't nobody got time to properly wash their hands for 30 seconds and then stand there completely drying their hands when they have 20+ chits on the go.

Edit: Forgot to mention, the majority of people don't know how to wash their hands properly, especially under the nails (both men and women). They've just used the hand dryer. Now you use the hand dryer. Multiply that by how many days it is before these things actually get cleaned and sanitised only to be contaminated again by the first user until the next clean and sanitise, if ever. Humans are filthy. 💀