Humans in the developed world spend more than 90 percent of their lives indoors, where they breathe in and come into contact with trillions of life forms invisible to the naked eye: microorganisms.

Source: "Are We Filtering the Wrong Microbes?" TEDGlobal 2011. Jul. 2011. Conference Presentation. Additional Information: This quote by ecologist and TED Fellow Jessica Green presents the fact that humans in industrialized countries spend the vast majority of their time indoors, where they breathe in trillions of microorganisms. The quote is from Green's 2011 TED Talk on indoor vs. outdoor microbes. Following this quote in her talk, Green goes on to say that while we also encounter microorganisms outdoors, the type of microorganisms found indoors are more harmful. According to Green, in mechanically ventilated air, you have a higher probability of encountering potential pathogens (disease-causing "germs") than you do outdoors. Watch the full TED Talk here: Jessica Green - Are We Filtering the Wrong Microbes?

“Are We Filtering the Wrong Microbes?” TEDGlobal 2011. Jul. 2011. Conference Presentation.