Methods: A cross-sectional study involving 324 of 396 full-time office workers of two office buildings in Rio de Janeiro downtown. The diagnosis of asthma relied on medical examination and positive answer to the European Community Respiratory Health Survey (ECRHS) asthma questionnaire, spirometry and positive skin prick test for aeroallergens (mites, fungi and cockroach). Standardized international methodologies were used to investigate the indoor concentration of TVOC, formaldehyde, mites and fungi in six floors of each building.
Results: There were 160 workers exposed to high TVOC concentrations, 111 to formaldehyde, 176 to mites and 58 to fungi. Allergic asthma was observed in 6.17% of the workers and non-allergic asthma in 9.26%. In the multivariate regression considering gender, age and exposure to TVOC, formaldehyde, mites and fungi, the unique significant risk factor was fungi exposure, for allergic asthma (OR 8.63 CI 95% 1.42-52.4 p 0.02) and non-allergic asthma (OR 4.76 CI 95% 1.39-16.9 p 0.01). There were no associations between asthma or allergic asthma and exposition to the others indoor pollutants.
Conclusions: Exposure to fungal allergen was an important risk factor for allergic and non-allergic asthma in office workers, but exposure to chemical indoor pollutants in offices seems not to be associated with asthma prevalence in this environment.