A nice little article in National Geographic about green & healthy homes

That influence stems from a startling stat: Americans spend an average of nearly 90 percent of their time indoors, according to the Environmental Protection Agency. Yet what we breathe indoors is on average two to five times more toxic than what is typically outside, the agency warns, because of poor ventilation and off-gassing of toxic chemicals from a host of products, from carpeting to furniture.

 

http://www.nationalgeographic.com/environment/urban-expeditions/green-buildings/surprising-ways-green-buildings-improve-health-sustainability/