Men's offices have ''significantly more bacteria'' than women's, new US research suggests.
Citing a study published in the journal PloS One on Thursday, Australia's Fairfax media wrote that an examination of 90 offices in New York, San Francisco and Tucson, Arizona, also found that office chairs and phones were the most bacteria-heavy surfaces, rather than keyboards and mice.
And the bacteria mostly came from human bodies — mainly skin, oral cavities and nasal cavities. They also noted a ''surprising number of bacterial genera'' associated with the digestive tract.
The researchers also found that San Francisco was cleaner than New York or Tucson, LiveScience reported. However, there was a corresponding difference in the soil-associated bacteria in Tucson, probably because of the different climate, researchers said.
The scientists suggested the difference between the sexes was due to bad male hygiene.
''Men are known to wash their hands and brush their teeth less frequently than women and are commonly perceived to have a more slovenly nature,'' they said.
However, larger body mass was also named as a possible cause for the difference between sexes.
"Humans are spending an increasing amount of time indoors, yet we know little about the diversity of bacteria and viruses where we live, work and play,'' Fairfax quoted lead researcher Scott Kelley, a microbiologist from San Diego State University, as saying.
Canadian Press quoted Kelley as discounting any suggestion that such bacteria put office users at risk.
"These are all yours — you brought these in. They're yours and they're not making you sick. You're fine," he said.
"We've long known that bacteria are everywhere. We're surrounded by them on all surfaces. We can culture them. But we really don't know who they are for the most part, and where they come from," he added.
Dr. Michael Gardam, head of infection control at Toronto's University Health Network, said that office workers shouldn't freak out.
"I don't want people to look at this study and go 'Oh my God, my office is filthy,"' said Gardam. "No, your office is covered in bacteria — like every other surface you're ever going to touch. They're everywhere. And that's normal."
The researchers said the study could be the first step in further research, such as analyzing so-called ''sick buildings.''