If you were recently standing on a polluted corner of a busy city sidewalk, well, maybe you did stop to wonder about what sorts of dirt and dust molecules were seeping into your body. But for most of us, especially when weíre in our own homes, the quality of the air weíre breathing is not a big consideration–or not even a consideration at all.

The truth of the matter is, the quality of air indoors (even in seemingly clean homes) can actually be far poorer than that of even the biggest, most industrialized, and dirtiest urban centers! To put that in plainer language: the air in your home could be worse for your health than the air you breathe walking through New York City or Beijing or San Francisco.

What causes such potent and potentially harmful indoor pollution? For starters, the indoor usage of substances like cigarettes and cigars, paint, coal, furniture polish, cleaning fluids, asbestos, space heaters, and so on, can create a build-up of hazardous particles. One should be familiar with Asbestos legislation too. The degree of severity often depends on whether or not there is adequate ventilation–how much outdoor air can get into the house, and vice versa.

A home with very poor ventilation will pose a much worse health threat to its inhabitants than a home with lots of open windows and excellent ventilation. Thatís not to say that homes with good ventilation canít still be polluted–in fact, they certainly can be.