Sick Building Syndrome (SBS) Among Workers of Two Buildings and Exposure to Indoor Fungal Allergens in Rio De Janeiro, Brazil

Background: Indoor air quality is important for workplace environment. The internal environment may be affected in sealed and non sealed buildings by its occupants through the work activities undertaken, the presence of equipment, plants, type of furniture, ventilation systems, the pollution of the outside air and the development of microorganisms The SBS has symptoms of cough, irritation of the nose or throat, headache, fatigue and difficulty concentrating. This study aims to determine the prevalence of SBS in workers of two buildings and its relationship with fungal exposure in the workplace.

Methods: One hundred and sixty of 210 more than 1 year full-time workers of a sealed building, and 164 of 186 employers from a naturally ventilated building in Rio de Janeiro downtown, were evaluated in a cross sectional study. The SBS diagnosis relied on medical examination and a score questionnaire. Three or more affirmative answers to the symptoms in the questionnaire were considered positive to SBS. Standardized international methodologies were used to investigate the indoor concentration of fungi, mites and endotoxin.

Results: The prevalence of SBS in the sealed building was 44.8%, and in the non sealed 48.6% (p=0.48). There was no significant exposure to fungi in the indoor environment of the sealed building, while in the ventilated one 35.4% of the workers were exposed. In the multivariate regression considering endotoxin, mite and fungi exposure, there were no associations with SBS in the sealed building. In the non-sealed building, fungi exposure was the unique significant risk factor for SBS (OR 3.11 CI 95% 1.29-7.48 p 0.01).

 Conclusions: SBS is related with personal and ambiental risk factors. Exposure to chemical products, mites, endotoxin and fungi are included in this last group. In the non-sealed building we found a clear association between fungi exposure and SBS, problably due to a higher relative humidity in this  environment and fungi growth.