There are several solutions to the problem of sick – building syndrome; the most important of these is cleaning the building. First, of course, experts must determine the specific cause in any one building. Then workers probably need to take out carpets, wallpaper, and ceiling tiles in order to remove mold and bacteria. Also, they need to clean out the air conditioning system and completely rebuild the system of ventilation. They should remove synthetic products and bring in natural products, instead, if they are available.