Single-Celled Office Mates, by the Thousands - New York Times

Men’s offices have more bacteria than women’s offices.

Not only that: Offices in New York City house more bacteria than those in San Francisco.

These are among the findings of a new study in the journal PLoS One that looks at bacteria in more than 90 offices in three cities â€" San Francisco, New York and Tucson â€" and on five types of surfaces: chairs, desktops, phones, computer mice and keyboards.

The bacteria count in men’s offices was 10 to 20 percent greater than in women’s.

“It could be men are just bigger â€" they have bigger mouths and more surface area â€" but it could also be that men are less hygienic,” said an author of the study, Scott Kelley, a microbiologist at San Diego State University.

By sequencing a gene that has the same function in all of the bacteria, the researchers also determined that their diversity appeared to be the same across the three cities, and in men’s and women’s offices.

“It was fairly uniform across all of the samples,” Dr. Kelley said.

Most of the bacteria can be traced back to soil and to the human mouth and skin. “You’re constantly probably shedding these bacteria in this environment,” Dr. Kelley said. “The people in the offices are the main source of these organisms.”

He emphasized that the findings were not a cause for alarm â€" just a glimpse into the day-to-day environment that most of us live in.

“It’s a baseline of what a healthy, normal situation is like,” he said. “These were just regular office buildings, where we have no evidence that people are getting sick.

“But if we do have a sick building, we can now look at what’s going on there.”