Air quality refers to the “purity” of the air we breathe, whether indoors or outdoors. We often hear about the impact of outdoor air pollution on our overall health and most of us have seen images of large or industrialized cities with smokestacks and dark clouds of toxic chemicals being released into the atmosphere. They are alarming images. But what about the toxic chemicals that we cannot see in the air we breathe indoors? Recent research has shown that our indoor environments can be more detrimental to our health than outdoor environments.