Spatiotemporal characteristics of aerosols dispersion and the exposure risk of dental staff in a dental clinic with different ventilation strategies

• A dental clinic was investigated with different ventilation strategies. • Four indicators were proposed to assess the spatiotemporal characteristics of aerosols. • Spatiotemporal characteristics of aerosols dispersion were analyzed. • Exposure risks of dental staff were quantitatively analyzed. • The MV with air supplying downward and exhausting upward has the best performance. Dental staff are exposed to occupational risks due to the unique diagnosis and treatment processes in dental clinics. It is crucial to implement appropriate ventilation strategies and airflow distribution techniques for the reduction of exposure risks. Based on the full-scale experiments and numerical simulation, this study conducted a comparative analysis of airflow distribution, aerosols diffusion and spatiotemporal distribution characteristics of aerosols in a typical dental clinic with three different ventilation strategies and seven different airflow distribution modes (displacement ventilation, stratum ventilation, and five different modes of mixing ventilation) in Wuhan, China. To assess the spatiotemporal characteristics of aerosols accurately, it proposed four indicators including suspension rate, deposition rate, exclusion rate, and inhalation exposure. The results demonstrated that the aerosol exclusion rate exhibited the highest value (64.3%), while the suspension rate displayed the lowest value (1.8%). In the dental clinic, employing a mixing ventilation strategy with air supplied and exhausted from the ceiling resulted in the lowest non-dimensional concentration of pollutants in the breathing area. The position of the air exhaust louvre has a significant impact on airflow distribution. The aerosol exclusion rate is higher when the exhaust vent is located on the upper side compared to when it is on the lower side. The maximum aerosol deposition rates are located at the ceiling, floor, and walls, in addition, the deposition rates on the doctor and assistant side is also higher, with the highest being 23.8 pcs/m 2 and 20.2 pcs/m 2 respectively. Inhalation exposure risk for dental staff generally peaked at t = 60-80 s. Specifically, under stratum ventilation conditions, the doctor experienced their highest exposure risk of 70.2 × 10 -10 μg/kg at t = 60 s, whereas for assistants it occurred at t = 120 s with an exposure risk of 31.9 × 10 -10 μg/kg. Furthermore, peak inhalation exposure risks varied depending on airflow paths in each ventilation strategy employed by dental staff. These research findings provide a theoretical foundation for controlling pollutants in dental clinics and safeguarding occupational health among dental staff.