New Study: Yale Researchers say findings might help efforts to improve indoor air quality.
A person’s mere presence in a room can add 37 million bacteria to the air every hour — material largely left behind by previous occupants and stirred up from the floor — according to new research by Yale University engineers.
We live in this microbial soup, and a big ingredient is our own microorganisms
said Jordan Peccia, associate professor of environmental engineering at Yale and the principal investigator of a study recently published online in the journal Indoor Air.
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.
Many previous studies have surveyed the variety of germs present in everyday spaces. But this is the first study that quantifies how much a lone human presence affects the level of indoor biological aerosols.
The research team measured and analysed biological particles in a single, ground-floor university classroom over a period of eight days — four days when the room was periodically occupied, and four days when the room was continuously vacant. At all times the windows and doors were kept closed. The HVAC system was operated at normal levels. Researchers sorted the particles by size.
