Office work is also no less dirty than toilet

The offices are home to more than 500 types of bacteria, equivalent to the amount of bacteria in toilets and airplanes. But not all offices are the same, because men's workplace contains more bacteria than women.

According to a new study, in developed countries, millions of people spend more than 90% of their time on indoor activities, mostly working from 8 hours or more without going out.

People are the main source of bacteria in offices. (Source: National Geographic)

Biologist Scott Kelley of San Diego State University and colleagues chose TP. New York, TP. San Francisco, Tucson State and Arizonza State, and check about 30 offices in each city.

The investigation team found that the microbial community in New York and San Francisco was 'indistinguishable' , since it is largely due to bacteria originating from common species that rely on humans.

Bacteria often fall from the skin and exist on the surface of the office. Tucson has a number of different types of bacteria than in New York and San Francisco, probably because the bacteria adapt to the type of desert land in this area.

Bacteria are most concentrated in phones and seats. People often keep their mouths close to the phone when talking, so the phone concentrates a lot of bacteria. But scientists find it hard to explain why seats are also rich in bacteria, probably because scientists are more likely to collect bacteria on the chairs than other surfaces, such as computer keyboards.

Scientists come up with two hypotheses that explain why men's workplaces are more bacteria than women. The first hypothesis is that men are not as clean as women, for example, they brush their teeth and wash their hands less often.

The second hypothesis suggests that male hands and mouths are larger than women, so there is more surface area for bacteria to thrive.

Although offices contain a lot of bacteria, researchers say the problem is not so serious that people don't need to panic but stay away from the office.