Hand dryers worse than paper towels for spreading germs
Researchers have discovered that when hands are poorly washed airborne germ counts are 27 times higher around air dryers in comparison with the air around paper towel dispensers. This shows that both jet and warm air hand dryers spread bacteria into the air and onto users and those nearby. "These findings are important for understanding the ways in which bacteria spread, with the potential to transmit illness and disease," said Professor Mark Wilcox, who led the study.
Researchers collected air samples around the hand dryers and also at distances of one and two meters away. They found that air bacterial counts close to jet air dryers were 4.5 times higher than around warm air dryers and 27 times higher compared with the air when using paper towels. Next to the dryers, bacteria persisted in the air well beyond the 15 second hand-drying time, with approximately half (48 percent) collected more than five minutes after drying ended and still detected in the air 15 minutes after hand drying.
Researchers collected air samples around the hand dryers and also at distances of one and two meters away. They found that air bacterial counts close to jet air dryers were 4.5 times higher than around warm air dryers and 27 times higher compared with the air when using paper towels. Next to the dryers, bacteria persisted in the air well beyond the 15 second hand-drying time, with approximately half (48 percent) collected more than five minutes after drying ended and still detected in the air 15 minutes after hand drying.
I'm fairly sure I saw this particular study, about hand dryers, back in the mid- to late-1990s, but it showed that several minutes after drying your hands left you with the same levels, regardless of which method you used.
Ultimately, this is only useful for modelling the spread of disease, as most people will not change their hand washing methods anyway.