The European Tissue Symposium has developed a Position Paper and additional documents which compare the different Hand Drying Systems.
This Position Paper is a short but comprehensive summary of a number of extremely important studies which have compared the hygiene aspects of using Paper Towels or Electric Hand Dryers.
Some of these studies have been sponsored by ETS, some are totally independent. 
The Position Paper below is a useful reference for those who need to decide about the Hands Drying system to be adopted in their facilities.

Position on the hygiene of electric air dryers versus paper hand towels – November 2022