"Mobile phones are frequently-used devices with clean or dirty hands in daily practice, including in hospitals," Dr. Ahmet Dilek of the Ondokuz Mayis University team told ABCNews.com. "[W]e found that most of the medical professionals do not clean their own cell phones, and most of the [unclean] phones carried important hospital pathogens."
Dr. Charles Gerba, a microbiologist and germ expert at the University of Arizona in Tucson, has performed similar studies on cell phones. He said that his past research, too, has found that cell phones harbor a variety of microbes -- some of which are pretty nasty.
"We have found [the superbug] MRSA on several cell phones," he said. "So we certainly find a lot of stuff on them -- particularly the flip kind, since they have surfaces that do not dry out."
The solution to this problem may be decidedly low tech -- disinfectant spray and a paper towel.
"They should be doing that at least once a day, if not maybe twice a day," Gerba said.
While the radiation that emanates from cell phones may not be enough to affect our brains, the conversations themselves might.
Specifically, researchers at Carnegie Mellon University studied the brain waves of drivers using cell phones -- and they found that even just listening to a conversation reduced the amount of brain activity devoted to driving by 37 percent. The quality of driving showed a "significant deterioration," according to the 2008 study.
"The science tells [us] when [we're] on the phone while driving, it is a high-risk activity -- very, very risky," Janet Froetscher, president and CEO of the National Safety Council, told ABC News correspondent Lisa Stark in a "World News" report in January. "But most people don't understand that."
Still, 80 percent of drivers admit to having had a cell phone conversation while driving, according to a May 2008 Nationwide Insurance poll -- even though more than 40 percent of those surveyed said they'd been hit or almost hit by another driver who was talking on a cell phone.
Even hands-free phones appear to contribute to unsafe driving. A 2005 study by the Insurance Institute for Highway Safety found that drivers using cell phones -- even hands-free -- were four times as likely to have an accident involving an injury, according to Ann McCartt, senior vice president for research at the Insurance Institute.
"I think there is still a big misconception among drivers and policymakers, intuitively, that a hands-free phone would be safer," she said. "And there may be a margin of safety there, but it is still unsafe."
Those behind the wheel may not be the only ones at risk of a cell phone-related auto accident. So suggests a study published in January in the journal Pediatrics that shows that children are more distracted while crossing the street if they happen to be talking on a cell phone.
Using a virtual reality setting, researchers studied 77 children ages 10 and 11 to see what effect cell phone conversations had on their ability to make it across the street safety.
What they found was that when children were on the cell phones, their attention to traffic -- the number of times a participant looked right or left -- went down 20 percent. The risk of getting hit by a car, or the number of close calls, went up 43 percent.