The sick building syndrome: prevalence studies.

Random samples or the entire workforce in nine offices in which similar clerical work was being performed were studied using a doctor administered questionnaire that inquired into symptoms that have been linked with the "sick building syndrome." Five of the offices were fully air conditioned, one had recirculation of air and mechanical ventilation, and three were naturally ventilated. Workers in three air conditioned and three naturally ventilated buildings were interviewed blind. Seven of the buildings were studied at our request in the absence of any known problem. Comparison of prevalences of symptoms between the naturally ventilated and the other buildings showed a repeated pattern of nasal, eye, and mucous membrane symptoms with lethargy, dry skin, and headaches. There were highly significant excesses of these six symptoms in the air conditioned buildings when compared by chi 2 tests with the naturally ventilated buildings. It is suggested that these six symptoms represent the sick building syndrome and that the size of the problem is probably greater than is currently recognised. Possible causes are discussed.