Biometrics poses no hygienic risks

device surface after 5, 20, 40, and 60 minutes to measure how many of the bacteria were still alive and could be transferred. Testers first touched the device surface, then a sterile plate or Petri dish containing growth media to allow any bacteria present to be more easily examined. The solution on the plate was allowed to grow for 24 hours at 37 degrees Celsius (approximately 99 degrees Fahrenheit). To test for bacterial transfer from the biometric device, the devices were sterilized, then testers wearing sterilized gloves touched the device surface and a sterile plate to measure how many bacteria were present before it was contaminated. Next, the device surfaces were contaminated with one species of bacteria at a time, and testers wearing sterilized gloves touched the device surface, then touched a sterile plate containing growth media fifty times. Just as in the other test, the solution was allowed to grow overnight to quantify the number of live cells recovered from touching the contaminated device.

Researchers found that E. coli survived on the devices slightly longer than staph bacteria, but within twenty minutes, nearly all of the bacteria had died on all three devices. Finally, a metal doorknob was tested with the same methods. Researchers found that the transfer of bacteria from the doorknob to another surface was nearly identical to that of the biometric devices. Blomeke said that on the doorknob, as well as on the three biometric devices, the majority of bacteria was transferred within the first ten touches.

Blomeke said that since naturally occurring organisms live on our skin at all times, as well as on frequently touched common surfaces, the fact that some bacteria live on biometric devices shouldn’t deter people from using them. “Biometric devices are the way of the future, and their use is growing rapidly,” she said. “In years to come, nearly everyone may be required to use the devices to enter buildings, pay for services or even clock in and out at work. Since there is the perception that these devices may cause illness, our study is important in that it at least establishes that a person is not any more likely to become ill from a biometric device that from a plain, old-fashioned doorknob.”

Blomeke said hygienic concerns - whether on high-tech or low-tech surfaces or devices - can easily be alleviated. “It’s always a good idea to get in the practice of washing your hands with soap and water or keeping antibacterial solution handy,” she said.