TORONTO - Offices are rife with bacteria, and not just in the washrooms, a new study suggests.
Scientists who set out to see how much and what kinds of bacteria are found in offices discovered there are plenty.
Men's offices contained more than women's, the researchers found. The arm rests of chairs and hand sets of phones had higher bacterial counts than desk tops or computer components — keyboards and mice.
But germaphobes should relax. The findings, published in the journal PLoS One, are no surprise.
Humans play host to swarms of bacteria all the time — on our skin, in our nostrils and mouths, and particularly in our digestive tracts. Where we are, they are.
"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," said senior author Scott Kelley, a microbiologist and professor of biology at San Diego State University.
Finding out what types are found in the average office environment was the impetus to do the study. There is no suggestion our microscopic companions put us at any risk.
"These are all yours — you brought these in. They're yours and they're not making you sick. You're fine," said Kelley.
Dr. Michael Gardam, head of infection control at Toronto's University Health Network, also stressed that people shouldn't freak out about these findings.
"I don't want people to look at this study and go 'Oh my God, my office is filthy,'" said Gardam, who was not involved in the research.
"No, your office is covered in bacteria — like every other surface you're ever going to touch. They're everywhere. And that's normal."
Gardam said the work is "kind of neat, in a geeky sort of way" but probably doesn't have any public health significance.
"It's kind of a state of the union of bacteria in our offices," he said.
Still, Kelley said that given how much time many people spend in an office, it's useful to get a picture of the microbial landscape of the modern work space. Knowing what is normal could allow researchers to figure out what's going on in cases of "sick building" syndrome, he suggested.
"I think it's worth studying because ... we're spending more and more time indoors. Something like 90 per cent (of the work day). Sometimes you just never go outside all day," he said.
He and his colleagues compared offices in three U.S. cities — New York, San Francisco and Tucson, Ariz. They took samples — swabbing surfaces — in 90 offices, 30 per city.
People working in the offices weren't given any warning, so they didn't have time to dive for the anti-bacterial wipes. "What we did is we just literally wandered down hallways. So they didn't really have any advance notice."
Testing revealed bacteria normally found on skin, in soil, and from the digestive tract. That latter type gave Kelley pause; it suggests hand hygiene may not be ideal in some offices.
The paper published in the journal suggests the difference between men and women might be related to hygiene too.
"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," the article said.
But in an interview, Kelley stressed a second theory. Men are generally bigger than women, and therefore have more surface space on which to carry bacteria.
"I favour the size hypothesis," he said in an interview.
"I don't think there's anything special about men. I don't think they have a special type of bacteria that women don't have. That they're spreading more or they're growing more. I think it's more to do with surface area."
The types of bacteria found in New York and San Francisco were indistinguishable, though the counts were much lower in San Francisco. Bacterial counts in Tucson were closer to those found in New York, but the types of bacteria were different, which Kelley put down to climactic variations.
But Gardam noted the geographic differences could be due to the ventilation systems in the buildings tested. "It may have nothing to do with Tucson, it's just the office building they picked," he said.
The Clorox Corporation was one of three funders of the work — Kelley's university and the Alfred P. Sloan Foundation were the other two. The article said the Clorox Corporation had no hand in the study and the scientists have no patents, products in development or other marketed products to declare.