Biometrics poses no hygienic risks

Here was another potential problem for biometrics: The technology is becoming more popular in a variety of applications, ensuring secure access to buildings and to bank accounts, but industries are finding that many users believe the devices are unsanitary and a potential source of germs which could cause illness. A Purdue University study, however, has found that while the platen glass surfaces of devices which scan fingerprints or hand geometry may look more unsanitary due to visible dirt and prints, they in fact harbor about the same amount of bacteria as a typical doorknob. Christine Blomeke, a researcher and doctoral student in Purdue’s Biometric Standards, Performance and Assurance Laboratory, performed the study along with lab director Stephen Elliott, an associate professor of industrial technology, and Thomas Walter, a continuing lecturer in the Department of Biological Sciences.

Blomeke said the study was conducted because of participant comments made during fingerprint and hand-geometry studies at the lab. She said the subjects, who were required to touch their hands or fingers to the sensors, questioned the cleanliness of the surfaces. “When you look at these devices, finger moisture, dirt and oils cause the surface to appear to be dirty,” Blomeke said. “In a study we did on this last year, more than a quarter of the participants indicated that they thought the devices were somewhat unsanitary. Since the use of biometric devices is rapidly expanding in public spaces, such as airports, stores and banks around the world, we felt it was important to examine whether touching these surfaces would subject users to more germs than they would be exposed to by touching objects such as pens, doorknobs and elevator buttons.” The results of the study were presented this week at the Institute of Electrical and Electronics Engineers International Carnahan Conference on Security Technology in Ottawa, Ontario, Canada.

Blomeke’s Boilermakers team examined the bacterial recovery and transfer from three types of biometric sensors: fingerprint, hand-geometry, and vein-recognition devices. Each sensor was tested separately with two kinds of bacteria: Staphylococcus aureus, a common cause of blood and skin infections, and Escherichia coli, commonly known as E. coli, which can cause diarrhea, urinary tract infections and meningitis. To test how well the bacteria could survive on a biometric device, the surfaces were first sterilized to kill existing bacteria, then coated with a bacteria culture. Testers used sterilized gloves to touch the biometric