The California Healthy Building Study assessed risk factors for building-related symptoms among office workers in 12 representative public office buildings in northern California, using a worker questionnaire, building inspections, and environmental measurements. No environmental contaminants measured were above existing health standards. Mechanical ventilation, either without air-conditioning (MECH) or with air-conditioning (AC), was associated with increased odds ratios (ORs), relative to natural ventilation, for a number of building-related symptoms, after adjustment for personal, job, and workplace factors in logistic regression models. Adjusted ORs [and 95% 'confidence intervals (CI)] for symptoms in MECH and in AC respectively included: eye symptoms, 1.7 [0.9-3.4] and 2.1 [1.1-4.0]; upper respiratory symptoms, 1.8 [1.0-3.2], and 1.9 [1.1-3.2]; multiple respiratory symptoms, 2.9 [1.0-8.0] and 2.8 [1.1-7.6]; multiple mucus membrane symptoms, 3.3 [1.2-9.5] and 3.4 [1.3-9.1]; and skin symptoms, 6.0 [1.6-22] and 6.0 [1.7- 21]. A set of symptoms (toothache, earache, and shoulder pain) hypothesized to be unrelated to indoor air quality was, as predicted, not associated with MECH or AC: 1.0 [0.5-2.1], and 1.1 [0.6-2.0], suggesting that reporting bias does not explain the findings. Exploratory adjustment for correlated occupant responses within study spaces, using generalized estimating equations, produced little change in most ORs or CIs. These findings corroborate European studies reporting that mechanical ventilation and air-conditioning are associated with increased risk of building-related symptoms. One potential explanation for these findings, supported by other research, is that building ventilation systems can produce or disseminate air contaminants.
Air-conditioning; Air-filters; Air-flow; Air-quality; Air-quality-control; Air-quality-measurement; Air-quality-monitoring; Biological-effects; Biological-monitoring; Breathing-atmospheres; Epidemiology; Exposure-assessment; Eye-irritants; Mucous-membranes; Occupational-exposure; Occupational-hazards; Occupational-health; Respiratory-irritants; Risk-factors; Skin-irritants; Statistical-analysis; Ventilation; Ventilation-equipment; Ventilation-systems; Work-environment; Worker-health; Work-organization; Workplace-studies
National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, DSHEFS, 4676 Columbia Parkway, Cincinnati, OH 45226
American Journal of Epidemiology. Abstracts of the 28th Annual Meeting of the Society for Epidemiologic Research, Snowbird, Utah, June 21-24, 1995