ABSTRACT
Over the past 30 years, a new man-made ecosystem has developed-the controlled environment within the sealed exterior shells of modern office buildings. Air pollution may occur in this indoor environment caused by the occupants, their work activities, equipment, plants, furnishings, building materials, and even the ventilation systems themselves. In the vast majority of office buildings in North America, the major mechanism to remove these pollutants and to provide a healthy, comfortable indoor environment is the heating, ventilation, and air-conditioning (HVAC) system. These highly automated systems are often run by only one or two operators. These operators have very little training in health and, in large buildings, have little contact with building occupants. When the sealed exterior shells of modern office buildings are damaged, water incursion through the building envelope can give rise to damp building materials and furnishings, which often support microbial growth.
