If you're like most people in North America, you probably spend most of your time indoors. Leave home in the morning, drive to work, stay in your cube all day, head home again. Ninety percent of our lives are spent inside a built environment of some kind – ones that we share with millions of invisible microbes.
Scientists increasingly recognize that rooms and buildings have their own microbiomes, and that those microbial roommates may affect the health of human inhabitants. Those microbes vary depending on what city you're in, according to a study published Tuesday.