Abstract
Bioaerosols play a significant role in indoor air quality (IAQ) as they can be the cause of several health problems, including acute allergies and infectious diseases. This study aimed to characterize and compare the microbial air quality of air-conditioned (AC) and naturally ventilated (NV) office rooms in the Upper Silesia region of Poland. The bacterial samples were collected during the late spring season. Culturable bacteria were deposited on the nutrient media on Petri dishes to investigate the viable-culturable count (VCC) of bacteria and bacterial community structure using a Biolog GEN III system. In total, 12 species of bacteria were identified, with the most isolated Macrococcus equipercicus, Micrococcus luteus D, Staphylococcus xylosus (indoor), and Bacillus species (outdoor). The indoor mean concentrations of bacterial aerosol ranged from 102 to 103 CFU m−3, below Polish proposals for threshold limit standards in office buildings. The indoor-to-outdoor (I/O) ratios indicated that studied air pollutants in the office rooms originated from the indoor air. These results, together with community composition of bacteria, indicate that most of the bacteria present in the studied office building were relatively fresh and of human origin. Multi-antibiotic resistance (MAR) tests showed that the most antibiotic-resistant features were present in Macrococcus species. The office building exposure dose (OBED) and mass median aerodynamic diameter (MMAD) of bacteria aerosol were estimated. The highest value of OBED over the study period was obtained for staff working in offices with natural ventilation (141 CFU kg−1), in contrast to the value for staff working in offices equipped with air conditioning (about 100 CFU kg−1). The MMAD of viable airborne bacteria was higher in AC offices (2.4 μm) than in NV offices (2.2 μm).
Highlights
People spend more than an average of around 87% of the day indoors (Lee and Chang 2000; Tringe et al 2008; Ashmore and Dimitroulopoulou 2009; Wichmann et al 2010)
The second observation is that the mean average concentration of the bacterial aerosol in the naturally ventilated office rooms was about 1.5 times higher (1360 CFU m−3) than mean concentration of bacteria obtained in air-conditioned office rooms (540 CFU m−3), which indicates that the type of ventilation can be a very important element in shaping of microbiological Indoor air quality (IAQ)
Viable-culturable count (VCC) of the bacterial aerosol was evaluated in two types of offices air-conditioned (AC) or naturally ventilated (NV) in an office building in Gliwice, Poland
Summary
People spend more than an average of around 87% of the day indoors (Lee and Chang 2000; Tringe et al 2008; Ashmore and Dimitroulopoulou 2009; Wichmann et al 2010). According to studies conducted in the last 20 years by the United States Environmental Protection Agency, indoor air is often more polluted than outdoor air, and indoor air Bioaerosol particles are one of the pollutants that can cause a reduction in IAQ in office buildings. They account for 5– 34% of indoor air pollution (Gizaw et al 2016).
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
