Indoor air humidity and sensation of dryness as risk indicators of SBS.

Questionnaire reports on symptoms and sensations from 4943 office workers, measurements of indoor climate from 540 office rooms in 160 buildings, and measurements of TVOC in 85 rooms were used in an analysis of the role of indoor air humidity and the sensation of dryness as risk indicators of SES (Sick Building Syndrome) symptoms. The sensation of dryness was strongly associated with the prevalence of SBS symptom reports. There were no associations between measured indoor air humidity and the prevalence of SBS symptoms or the sensation of dryness. A number of significa1u associations were demonstrated between the sensation of dryness and technical, air quality, psychosocial and personal variables. The frequency of reports of perceived "dry air" is an important indicator of the "sickness" of a building; indoor air humidity is not an indicator.