Studies have shown that for every cubic meter of air in an office building, there are about a billion bacteria swarming about. Yet very little is actually known about these bacteria, how they get in and where they are most likely to be found.
"While we have long known that bacteria can be found everywhere we look, this study shows that we are only beginning to understand the diversity (of bacteria) found in human environments," said Scott Kelley, a biologist at San Diego State University and lead author on the study.
"This study provides detailed baseline information about the rich bacterial communities in typical office settings and insight into the sources of these organisms," he said.
The research, conducted by microbiologists and environmental scientists at SDSU and the University of Arizona, appears in this week's journal of the Public Library of Science.
To get a handle on the makeup of indoor office air, the researchers tested rooms and buildings in San Francisco, New York and Tucson, Ariz.
They swabbed chairs, desks, keyboards and phones. And they made a point to test an equal number of men's and women's offices.
They found that San Francisco offices were the cleanest, but the types of bacteria didn't differ all that much from those found in New York. Tucson, however, had different germs entirely, and the researchers suspect the desert environment is likely the cause.
Researchers also found that chairs and phones were the most contaminated items in an office – home to several different kinds of oral, nasal and intestinal bacteria. Keyboards, desktops and computer mouses were cleaner.
The big surprise was the difference between men's and women's offices: Men's were crawling with bacteria. Kelley said men's offices generally had 10 to 20 percent more than women's offices. He said this could likely be explained by two factors.
"Men are known to wash their hands and brush their teeth less frequently than women," wrote the authors, "and are commonly perceived to have a more slovenly nature."
They also say that because men are generally larger than women, they have more bacteria to shed.
"Thus, in addition to being less hygienic, it is possible that men may also shed more bacteria into their surrounding environment," they wrote.
Kelley said future research will examine seasonal variations and include a broader range of climates. But the bottom line, he said, is that it is human bacteria – brought in by workers and spread around – that make up the vast majority of the germs found in office environments.
Story courtesy of our media partners at California Watch (A Project of the Center for Investigative Reporting)