Sick building syndrome: The term "sick building syndrome" (SBS) is used to describe situations in which building occupants experience acute health and comfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified. The complaints may be localized in a particular room or zone, or may be widespread throughout the building.
A 1984 World Health Organization Committee report suggested that up to 30 percent of new and remodeled buildings worldwide may be the subject of excessive complaints related to indoor air quality (IAQ). Often this condition is temporary, but some buildings have long-term problems. Frequently, problems result when a building is operated or maintained in a manner that is inconsistent with its original design or prescribed operating procedures. Sometimes indoor air problems are a result of poor building design or occupant activities.
Building occupants complain of symptoms associated with acute discomfort, including headache, eye, nose, or throat irritation, dry cough, dry or itchy skin, dizziness and nausea, difficulty in concentrating, fatigue, and sensitivity to odors. The cause of the symptoms is not known. Most of the complainants report relief soon after leaving the building.
Some of the causes of SBS are inadequate ventilation, chemical contaminants from indoor sources - carpeting, upholstery, manufactured wood products, copy machines, chemical contaminants from outdoor sources - motor vehicle exhaust, poorly located intake vents, biological contaminants - mold, pollen, and from materials that may have become wet through a leaky roof or air cooling system. These elements may act in combination, and may supplement other complaints such as inadequate temperature, humidity, or lighting. Even after a building investigation, however, the specific causes of the complaints may remain unknown.
This information is from Indoor Air Facts No. 4 (revised) Sick Building Syndrome from the US EPA, last updated 9/2010.