So, for most people, poor indoor air quality poses a greater risk than polluted outdoor air.
Many office buildings have significant air pollution sources.
In addition, these buildings may be inadequately ventilated. Mechanical ventilation systems, for example, may not be designed or operated to provide adequate amounts of outside air. And people generally have less control over their office environments than their homes. In recent years, however, there has been an increase in the incidence of immediate health problems related to indoor air pollutants in office environments. A number of well-identified illnesses, such as Legionnaires' disease, asthma, hypersensitivity, pneumonitis and humidifier fever, have been directly traced to specific building problems.