Quantitative and qualitative assessment of microbial aerosols in different indoor environments of a dental school clinic

In the indoor environment of dental clinics, dental staff and patients are exposed to various types of infectious agents transported by aerosols and particles, generated during dental procedures, promoting an increased risk of cross-infection. The aim of this study was to determine the levels and diversity of microbial aerosol in relation to particle load in five different departments of a dental school clinic. The air samples were collected by an active single-stage Andersen sampler during the treatment procedure. The mean concentrations of airborne bacteria were in the range of 52–1030 and 8–844 CFU/m(3) at the distances of 0.5 and 2 m, respectively. Bacterial aerosols in pediatric, endodontics, and restorative wards and fungal aerosols in all the sampling wards were significantly higher at the distances of 0.5 m. The dominant bacteria and fungi were identified as Micrococcus, Bacillus, Streptococcus, Staphylococcus, Penicillium, Cladosporium, Aspergillus, Rhizopus, and Alternaria. The positive associations were also obtained between bacteria and fungi levels and particulate matter (PM) concentrations.