Who would have ever thought that using a high powered hot air hand dryer would add bacteria? Especially one of those new versions that give you the sensation they’re about to remove your wedding ring (and your digit with it) or could do a very proficient job of removing any residual house paint through skin exfoliating - not to mention providing the same ear-piercing sound of a jet engine passing overhead.
Researchers recently tested the amount of bacteria left on the skin after hands were dried using a hot air hand dryer versus the humble, but very effective (as it turns out) paper towel method; yes there are people that are paid to test such thing. The results were jaw dropping!
Washing your hands and then using paper towels or continuous-loop cotton towels, reduced the bacterial count by 45-60 per cent, not perfect I’ll give you, BUT…using a warm air dryer in fact increased the bacterial count by an average of 255%.
"It turned out the bacteria were already inside the warm air dryers thanks to the moist environment," Dr. Karl Kruszelnicki (yes, he's a real doctor) wrote in his book Curious and Curiouser.
"Every single warm air dryer had high bacterial counts on the air inlet, while 97 per cent had them on the outlet nozzle surface, too."
Like a good ol’ sneeze, it would appear that air-based hand dryers actually spread bacteria and other germs via tiny droplets - like a really disgusting aerosol.
In fairness, good Dr Kruszelnicki did point out that our bodies are resilient enough to keep most of these bacteria at bay, but suggests you reach for towels (preferably recyclable) over driers, as they dry your hands quicker, providing the friction needed to shift bacteria that you don't get from a hot gust of warm air.