EFFECT OF A NEW VENTILATION SYSTEM ON HEALTH AND WELL-BEING OF OFFICEWORKERS

Sick building syndrome is the term given to a heterogeneous constellat ion of symptoms that affects workers in modern mechanically ventilated office buildings. Although the cause is unknown, there is evidence th at the local environment of the work station is an important determina nt of symptoms. In this study, investigators examined the effect of a new, individually controlled ventilation system on workers' symptoms. Investigators studied two groups of workers in one mechanically ventil ated office building: (1) a control group at whose worksite no interve ntion was made and (2) an intervention group. The intervention consist ed of installation of a device that allowed each worker control over t he ventilation supplied to his or her worksite. Just before, and 4 and 16 mo after installation of this device, workers completed self-admin istered questionnaires regarding occurrence of symptoms. The new venti lation system resulted in higher air velocities, more variable tempera tures, and higher concentrations of airborne dust and fungal spores. F our months after installation, workers with the new ventilation system reported fewer symptoms that were (a) work-related (p < .05) and that were work-related and frequent (p < .05); in addition, they reported fewer symptoms that reduced their capacity to work (p < .01). Sixteen months after installation, workers with the new device reported fewer symptoms than at baseline (although not as significantly), and they in dicated that the indoor air quality improved their productivity by 11% , compared with a 4% reduction of productivity among the control group of workers (p < .001). Investigators concluded that the new ventilati on system, which provided the workers with individual control over ven tilation, was associated with important and sustained reduction in sym ptoms.