Researchers led by Jordan Peccia conducted the study in a single ground floor classroom at the university over a period of eight days. The researchers analyzed the air content with the room being periodically occupied for the first four days and remaining empty for the next four days. The researchers also made sure that the windows of the classroom were shut throughout the study period.
The researchers found that more than 37 million bacteria were stirred up every time someone entered the room. Majority of the bacteria were already present in the room, left by previous occupants and had settled on the floor.
"We live in this microbial soup, and a big ingredient is our own microorganisms. Mostly people are re-suspending what's been deposited before. The floor dust turns out to be the major source of the bacteria that we breathe", Jordan Peccia said.