Whose Offices Are Germier? Men vs. Women

If you're reading this at work, brace yourself. A new study shows that typical offices have hundreds of types of bacteria in them, and men's offices have the most.

Researchers report finding more than 500 different types of bacteria on common surfaces in offices in three major U.S. cities. And, perhaps less surprisingly to some people, they found that men's offices are more contaminated than women's.

"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," says lead researcher Scott Kelley, PhD.

The San Diego State University biologist and his team swabbed five common office surfaces -- chairs, phones, desks, computer mice, and keyboards -- in 90 different offices, 30 each in San Francisco, New York, and Tucson.

The research team, which was partially funded by the Clorox Corporation, found bacteria on nearly every surface they tested. Most of it came from the office workers themselves. Coughing and sneezing accounted for a good deal of the bacteria, as did shedding from the skin. However, a substantial amount came from deeper inside the body.

"We also found a surprising number of bacterial genera associated with the human digestive tract," the researchers write in the study, which appears today in the online journal PLoS ONE.

If all this sounds rather alarming -- or simply gross -- the researchers point out that there is likely little cause for concern for the vast majority of people who spend eight hours a day in an office: "[M]ost of the human-associated bacteria we found ... would only be a potential problem with severely immune compromised individuals."

On top of that, the researchers say that the dry, cool atmospheres of most offices do not lend themselves to bacterial growth.

Men Are Greater Source of Bacteria Than Women
As for the main suppliers of the bacteria, Kelley and colleagues say that men are responsible for a higher germ count than their female co-workers. Part of that may be explained by the fact that men are, in general, larger than women, which means they have more surface skin to provide a breeding ground for bacteria. However, the researchers cite previous scientific literature to offer another possible explanation.

"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 researchers write.

And the Germiest Spots Are ...
Office co-workers are not the only source of bacteria. Dirt is another main supplier of contamination. And the most common surfaces on which bacteria were found? Telephones and chairs.

The researchers also found that the San Francisco offices they tested were less contaminated than those in New York and Tucson. They were not sure why this should be the case.

The researchers hope that these types of bacterial profiles of office spaces will help public health officials get to the bottom of disease outbreaks that can occur in office settings.

By: Matt McMillen
Reviewed by: Michael W. Smith, MD

Men's desks are germier than women's

You'd probably rather not think about it, but there are hundreds of species of bacteria on your desk, according researchers who sampled offices in three U.S. cities.

The study identified at least 500 species of bacteria in the offices, and found that men's offices tended to be germier than women's.

And although offices in New York City and San Francisco had similar types of bacteria, those in the Golden State were less contaminated than those in the Big Apple, the researchers said.

But don't go running for the hand sanitizer just yet although the findings have an "ick" factor, bacteria in your office are not necessarily something to worry about, the researchers said. After all, many bacteria are harmless, and actually helpmaintain human health.

"You shouldn't be worried in your own office it's you; it's just a reflection of who you are," said study researcher Scott Kelley, an associate professor of biology at San Diego State University, referring to the bacteria you find on your typical desk or keyboard. These bacteria are "with us all the time, and they don’t make us sick," he said.

Rather, the researchers said they hope that by documenting the various bacteria present in buildings with generally healthy people, scientists will be able to spot out-of-the norm bacteria that cause health problems, Kelley said. Such bacteria might turn up when something in the building changes, such as the air vents, he said.

Although we spend about 90 percent of our lives indoors, surprisingly little is known about the diversity of bacteria in environments such as offices, Kelley said, including how much is there and where it comes from.

Kelley and colleagues sampled a total of 90 offices from buildings in New York City, San Francisco and Tucson, Ariz. The researchers swabbed employees' chairs, phones, desktops, computer mice and keyboards. They analyzed the bacterial DNA to identify the types and amounts of bacteria present.

Most of the bacteria they found came from human skin or the nasal, oral or intestinal cavities, the researchers said. Bacteria from soils were also common, Kelley said.

Although you might expect the computer to be a germ magnet, more bacteria were found on office chairs and phones than on keyboards and computer mice, the researchers said.

Men had about 10 to 20 percent more bacteria in their offices, on average, compared with women.
This may be because men, research finds, tend to be less hygienic. "Men are known to wash their hands and brush their teeth less frequently than women, and are commonly perceived to have more slovenly nature," the researchers wrote in the May 30 issue of the journal PLoS ONE.

In addition, men are typically larger than women, and thus have a greater surface area for bacteria to live in and shed from, the researchers said.

New York City offices were the germiest, and those in San Francisco were the cleanest in terms of bacteria quantities. However, more buildings would need to be sampled before conclusions could be drawn about whether this is a typical pattern for offices in these regions, and what might be causing these differences, Kelley said.

While similar types of bacteria were found in New York and San Francisco, samples from Tucson looked different, possibility because the southern city has a different climate. Samples from Tucson tended to have fewer bacteria from the groups called Bacteroidetes and Cyanobacteria compared with the other two cities.

The researchers next plan to look at the types of molds present in offices, Kelley said.
The study was funded in part by Clorox Corporation; the cleaning product manufacturer had no role in study design, data collection or analysis.

By: Rachel Rettner