Fresh air feels so good. My dog, Trystan, loves when I put his window down. His whole head hangs out and he breathes in all the scents and air. We may have smog in LA but I have it under good authority that the air outside in LA is healthier than the air inside. Everything in our homes emits toxins into the air. Our cleaning agents, dish soap, varnishes, plastics, non-organic cotton clothes, sheets, blankets, shoes, soles, pens, pencils, carpets and the list goes on.
One of the healthiest things you can do daily is to open all the doors and windows in your house for an hour. Just an hour helps cleanse the air. If it is completely impossible to open your home or office, turn on fans (clean the blades monthly) and get the air moving.