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The Daily Wildcat

The Daily Wildcat


Prof. talks dirty on germ research

Alex Kulpinski
Grad students test bacteria and germs in a lab in the Veterinary Science and Microbiology Building. Lydia Stern/ Arizona Daily Wildcat

It turns out that phones, desktops and keyboards harbor the most germs in an office setting, far exceeding the amount of bacteria found on the average toilet seat, according to research led by a UA professor.

Charles Gerba, a professor in soil, water and environmental science department, tested various offices in New York, Chicago, San Francisco and Tucson and found that a desktop contains about 400 times more bacteria than a toilet seat.

“Women’s desks have more bacteria and mold than men’s, because 70 percent of women from what we found store food in their desk, where only about half that number of men do that,” Gerba said.

Toilet seats were among the cleanest surfaces found in offices as well as restrooms, with taps and sinks containing the most fecal bacteria.

“If there’s ever an epidemic of anything, you should run into the bathroom, drop your pants and sit on the toilet because it’s the safest place,” Gerba said.

While public restrooms are cleaned on a daily basis, some of the most touched areas in an office are overlooked when cleaning, causing germs to spread rapidly in just one workday.

“When you think of stuff to clean in the office, the phone is not the first thing that’s going to come to mind, but a toilet is going to get cleaned two, three times a day because that’s what people think of as germy and disgusting,” said Ben Rosenfield, a pre-business freshman.

Gerba said he has been testing germs on indoor surfaces and objects for 15 years. Gerardo Lopez, a soil, water and environmental science graduate student focusing on the spread of infectious disease in the environment, has worked with Gerba in testing different surfaces to see which transferred the highest level of germs. Lopez would put non-pathogenic bacteria on a certain surface and wait 30 minutes. He would then touch the surface, swab his finger and take the results back to the lab for testing. The nature of the test itself sometimes made it difficult to obtain samples, according to Jonathan Sexton, a soil, water and environmental science graduate student.

“A lot of times, especially when you’re dealing with businesses … they don’t want you to find anything so you’re not always allowed to (obtain samples). So a lot of times you have go undercover and do it,” Sexton said. “It is not uncommon to be kicked out of places.”

Consumer product companies, such as Clorox and other disinfectant product companies, fund this research. The college-age generation is the “touch generation,” Gerba said, because students spend about 80 percent of their time indoors and are constantly touching things.

The spread of germs lead to the common cold and flu, something that can be prevented if people wash their hands more often, Gerba said.

Dirty facts

70 percent of people wash their hands in public restrooms.

60 percent of people don’t know how to properly wash their hands.

College students bring their hands to their face 16 times an hour.

Researchers found that they reduced absenteeism by 50 percent when disinfecting school desks.

Source: Charles Gerba,
UA professor of soil, water and environmental science

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