More than we eat, more than we drink, more than anything else we do in our lives, we breathe. It’s the one thing, other than maybe our heartbeat, that continues to happen even when we aren’t thinking about it. But even if breathing is something we do subconsciously, we should not ignore issues of air quality. Pollutants in the air are too small for us to see, yet poor air quality has been linked to multiple health problems from cardiovascular disease, cystic fibrosis, lung disease or the rather unknown sick building syndrome. Knowing what’s in our air and keeping it healthy is as essential as knowing what’s in the food we eat or water we drink.