Sick-building syndrome.

The sick-building syndrome (SBS) is defined as the occurrence of an excessive number of subjective complaints by the occupants of a building. These complaints include headache, irritation of the eyes, nose, and throat, lethargy, inability to concentrate, objectionable odors, and less frequently, nausea, dizziness, chest tightness, etc. These complaints will always be reported by a fraction of the occupants of any building if a questionnaire is administered that asks the respondent to recall any subjective symptoms they remember having had in the last 2 weeks or or over some period of time. It is often considered that SBS symptom reports have a minimum prevalence of about 15 to 20% for a 2-week recall period. SBS symptoms reported by 30% or more of occupants are indicative of conditions in the building environment that warrant attention. It is not often that a clear, single cause is responsible for the excess symptom reports. The following factors, often in combinations, are seen to contribute to SBS: outdoor air supply that is inadequate, ventilation distribution or effectiveness that is inadequate, the presence of temporary or long-term sources of contaminants such as tobacco smoke, adhesives, composite materials such as chipboard, and the growth of microorganisms in the HVAC equipment or in carpets or other furnishings. Depending on which causes contribute, the condition may be intermittent or even temporary. Psychosocial factors such as labor-management relations and satisfaction or dissatisfaction with other factors in the work environment can have a profound influence on the level of response of the occupants to their environment. Although hard data are difficult to collect, it is likely that productivity in the office environment is sensitive to conditions causing SBS.