Bathroom air can contain bacteria and viruses. These harmful particles can be thrown into the air from the toilet bowl as you flush. Some originate from fecal matter and can cause sickness, vomiting and diarrhea.
 
Ian Eames, Professor of Fluid Mechanics at the University College London, says: “Fecal matter and droplets of urine can be found in washroom air. These small particles can stay in the air and can be transported around the washroom area. Most hand dryers draw in contaminated air and direct it straight onto your hands. If a hand dryer with a HEPA filter is used, cleaner air is directed onto hands and expelled into the room. Both of these effects are beneficial to washroom users, especially in hospital environments.”
 
Research published in the American Journal of Infection Control shows that toilets can cause bacteria and viruses to be thrown into washroom air. At the point of flushing a toilet a plume of air is produced. This allows microorganisms from within the toilet to be dispersed into the air around you. A study in The Journal of Hospital Infection shows that bacteria found in fecal matter can become suspended in washroom air after the toilet is flushed. These microorganisms can stay suspended in the air for over an hour.
 
According to Dyson, conventional hand dryers can draw in this contaminated air, blowing bacteria directly onto washed hands. Hands are a major vector for harmful microorganisms, with more than 80 percent of infectious diseases being transmitted by touch. Damp hands can spread 1000 times more bacteria than dry hands. Therefore drying your hands is just as important as washing them properly.