Imagine someone you live with might have been exposed to the coronavirus. What would you do? Rob Roy Britt found himself in that situation. In Elemental, he writes about several tactics to reduce the risk of infection should someone bring the pandemic home. Before you plunk down big bucks for specialized air filters or a high-tech device, know this: Air circulation, including fresh air, matters a great deal. Opening the windows, when practical, is a very effective way to reduce or eliminate coronavirus aerosols, just as a good breeze can clear cigarette smoke.