A study by the University of Connecticut sought to discover if hand dryers were helping to disperse germs, or were in fact simply redistributing them.
The paper found that dryers actually spread germs.
Flushing the toilet with the lid open can send faecal particles into the air, where they can linger until the hand dryer is switched on, with the particles heated up in the machine and spat back into the user’s hands.
The hands being wet is a particularly healthy environment for gems to thrive in.
“These results indicate that many kinds of bacteria, including potential pathogens and spores, can be deposited on hands exposed to bathroom hand dryers and that spores could be dispersed throughout buildings and deposited on hands by hand dryers,” the study concluded.
Researchers suggest fitting dryers with HEPA (high efficiency particulate air) filters, which can reduce the bacterial deposition by four times. Alternatively paper towels are found to be more hygienic, but that option is also less environmentally friendly and potentially more costly. The consequence of hand dryers spreading faecal matter is unlikely to have a serious effect on your health, however, as many day-to-day items, such as mugs and desks, are also covered in germs.