The indoor environment is central to public health because we spend so much time there. Concentrations of most pollutants are higher indoors, often as much as ten or more times higher than in outdoor air. A person is generally 1000 times more likely to inhale a chemical molecule if it is emitted indoors rather than outdoors. The potential importance of the http://desdes.net78.net indoor environment is further enhanced by the fact that pollutants emitted indoors have greater source strengths than outdoors on the basis of area. But efforts to address indoor pollutants and provide healthful and productive indoor environments often conflict with efforts to protect the larger environment from the adverse effects of our building technologies. “Sustainability” has been defined variously, as was clearly illustrated at the recent United Nations Earth Summit in Johannesburg.