Characterization of Indoor Air Bioaerosols in an Electrical Headquarter Building

Abstract

Bioaerosols may produce poor indoor air quality and affect the health of the building occupants. We identified bacteria and fungi from bioaerosols and determined the microbial density values by the impaction method on solid surface in 104 locations distributed in 26 floors from an electrical headquarter building. Indoor contamination was interpreted as follow: >500 CFU m⁻³, indoor microbial density higher than the outdoor microbial density and pathogenic isolate. Results showed bacterial density values from 28 CFU m⁻³ to 522 CFU m⁻³ from which 18 theatres exceeded the non-contaminated density range, overcame the outdoor average density value (198 CFU m⁻³) or depicted the presence of the pathogenic bacteria Staphylococcus aureus and/or Staphylococcus saprophyticus. Other bacterial opportunistic pathogens were isolated. Airborne fungal detection depicted density values from 2 CFU m⁻³ to 800 CFU m⁻³. Fungal density values exceeding the non-contamination range were detected in 12 theatres distributed in 7 floors. No pathogenic fungi were detected. However, opportunistic pathogen or sick building syndrome (SBS)-associated fungal isolates, particularly Penicillum and Aspergillus, were widely distributed in almost all floors. Even though we did not associate our findings with SBS and building-related illness (BRI), we showed that this culture-based analysis proved to be an adequate way to determine the microbiological indoor air quality.