According to a 2008 study at University of Westminster, hand dryers increase the presence of bacteria on the finger pads and palms after using them compared to paper towels that reduce bacterial presence by almost 80% on the finger pads and palms.
The credibility of the study, however, is a little off. The study was paid for by the European Tissue Symposium. Some supporters of the hand dryer's effectiveness say the study's results were questionable.
Instead of asking which of the hand drying methods kill more bacteria, why don't you ask whether most people know how to correctly wash their hands. Getting rid of bacteria starts with hand washing, and not with hand drying.
A separate study proved that people wash their hands infrequently after using the toilet. If they do wash their hands, they make a botched job out of it. Too few bacteria are eliminated from flowing water. Washing one's hands correcttly is teh only way to stop the germs from spreading sickness. The following describes the steps in correctly washing the hands.
Lather up your palms and fingers and scrub your skin with your nails. Scrub lightly around your palms, the back of your hands, the sides, the underside of your fingers, and then around your fingers. Take care to scrub the webbing of skin in between the fingers. Scrub down for at least 20 seconds with an anti-bacterial soap. This is the same span of time as singing 'Happy Birthday To You' twice.