There are several potential sources that can contaminate your indoor air. Poor ventilation is one of them. If the building doesn’t have a proper ventilation system, the polluted outdoor air enters the building with no way of exiting. Not keeping the HVAC system clean and up-to-date is another reason. If there is moisture damage in the environment due to high humidity, that can also lead to poor indoor air; moisture allows mold and mildew to grow. If remodeling or construction activities are going on around you, it could impact the quality of indoor air. If the air both outdoors and indoors is already contaminated, your IAQ is bound to suffer. Indoor Doctor can conduct air quality testing to let you know what’s going on with the air inside your home/building and recommend ways to rectify it.