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.
For non-critical situations, or situations involving electronic devices, stethoscopes, blood pressure cuffs, beds, monitors and other general hospital equipment, intermediate level disinfection is required. "Clean all equipment between patients with alcohol, use protective covering for non-critical surfaces that are difficult to clean, and hydrogen peroxide gas. . .for reusable items that are difficult to clean." Sterilization
Sterilization is a process intended to kill all microorganisms and is the highest level of microbial kill that is possible.Sterilization, if performed properly, is an effective way of preventing Infections from spreading. It should be used for the cleaning of  medical instruments and any type of medical item that comes into contact with the blood stream and sterile tissues.There are four main ways in which such items are usually sterilized: autoclave (by using high-pressure steam), dry heat (in an oven), by using chemical sterilants such as glutaraldehydes or formaldehyde solutions or by exposure to ionizing radiation. The first two are the most widely used methods of sterilization mainly because of their accessibility and availability. Steam sterilization is one of the most effective types of sterilizations, if done correctly which is often hard to achieve. Instruments that are used in health care facilities are usually sterilized with this method. The general rule in this case is that in order to perform an effective sterilization, the steam must get into contact with all the surfaces that are meant to be disinfected.