Good hand hygiene is essential to stop the spread of bacteria, however just as important is how you dry your hands afterwards. Now a new study has found that modern hand dryers in public toilets spread more germs than paper towels.

Scientists from the University of Leeds in the UK looked at high powered ‘jet air' hand dryers, as well as warm air dryers, and found that they actually spread germs into the air, onto the person using the dryer and onto anyone standing close by.

The scientists carried out their research by contaminating hands with Lactobacillus, a harmless type of bacteria that is not usually found in public bathrooms.

They then collected air samples from around the hand dryers and from distances of up to two metres away. If Lactobacillus was detected, it was known that it had come from the contaminated hands.

The study found that the air bacterial count next to ‘jet air' hand dryers was 4.5 times higher than the count around warm air dryers. It was also a huge 27 times higher than the count around paper hand towel dispensers.

The study also found that bacteria persisted in the air long after the 15 seconds of hand-drying time. In fact, around half of the bacteria was collected at least five minutes after drying had been completed and there were still traces in the air 15 minutes later.

"Next time you dry your hands in a public toilet using an electric hand dryer, you may be spreading bacteria without knowing it. You may also be splattered with bugs from other people's hands. These findings are important for understanding the ways in which bacteria spread, with the potential to transmit illness and disease," commented the study's lead scientist, Prof Mark Wilcox.

Details of these findings are published in the Journal of Hospital Infection.