Hand jet dryers create an "aerosol that contaminates the toilet room."
A new international study carried out by the European Tissue Symposium has found that the quick-blast hand dyers found in public loos spread bacteria and viruses around the room if people haven't washed their mitts properly before using the gadget.
Mark Wilcox, professor of medical microbiology at the University of Leeds, told Sky News: "The dryer creates an aerosol that contaminates the toilet room."
Staphylococcus aureus, which causes a range of conditions such as MRSA, was found three times more often on the surfaces of air dryers compared to towels.
The location in which the hand dryer has been installed also played a huge part in how much bacteria was spread around as, according to the research published in the Journal of Hospital Infection, the sinks, mirror and floors can all be covered.
Wilcox added: "If people touch those surfaces, they risk becoming contaminated."
The study also found that paper towels "absorb the water and microbes left on the hands and if they are disposed properly, there is less potential for cross-contamination."
Three hospitals in the UK, France and Italy were used in the experiment and it found that bacteria counts were significantly higher on the days when the air dryers were used.
Wilcox explained: "We found multiple examples of greater bacterial contamination on surfaces, including by faecal and antibiotic-resistant bacteria, when jet air dryers rather than paper towels were in use. Choice of hand drying method affects how likely microbes can spread, and so possibly the risk of infection."