Of those three methods, only paper towels reduced the total number of bacteria on hands, with "through-air dried" towels the most effective.The presenters also carried out tests to establish whether there was the potential for cross-contamination of other washroom users and the washroom environment as a result of each type of drying method. They found that:
the jet air dryer, which blows air out of the unit at claimed speeds of 400 mph, was capable of blowing micro-organisms from the hands and the unit and potentially contaminating other washroom users and the washroom environment up to 2 metres away
use of a warm air hand dryer spread micro-organisms up to 0.25 metres from the dryer
paper towels showed no significant spread of micro-organisms.In 2005, in a study conducted by TUV Produkt und Umwelt, different hand drying methods were evaluated. The following changes in the bacterial count after drying the hands were observed:

Cleaning, Disinfection, Sterilization
The field of infection prevention describes a hierarchy of removal of microorganisms from surfaces including medical equipment and instruments. Cleaning is the lowest level, accomplishing substantial removal. Disinfection involves the removal of all pathogens other than bacterial spores. Sterilization is defined as the removal or destruction of ALL microorganisms including bacterial spores. Cleaning
Cleaning is the first and simplest step in preventing the spread of infection via surfaces and fomites.
Drug Information Portal. U.S. National Library of Medicine. "Umbralisib". NCI Drug Dictionary. National Cancer Institute.