Evaluation of bioaerosol exposures during hospital bronchoscopy examinations

During hospital bronchoscopy examinations, aerosols emitted from the patient's during coughing can be found suspended in the ambient air. The aerosols can contain pathogenic microorganisms. Depending on their size, these microorganisms can remain in the air for a long time. The objective of this study was to measure the sizes and concentrations of the biological and non-biological particles produced during bronchoscopy examinations, and to propose preventive or corrective measures. Two bronchoscopy rooms were studied. An aerodynamic particle sizer (UV-APS) was used to establish the concentrations of the particles present and their size distributions. This instrument determines the aerodynamic diameter of the aerosols and can distinguish fluorescent (bioaerosols) and non-fluorescent particles. Reference concentrations were measured before the start of the examinations (morning background concentrations). They were used as comparison levels for the concentrations measured during and at the end of the bronchoscopies. In parallel, computational fluid dynamics (CFD) made it possible to isolate and understand different factors that can affect the concentration levels in bronchoscopy rooms. The concentrations of the non-fluorescent and fluorescent particles (bioaerosols) were significantly higher (p ≤ 0.05) during the bronchoscopy examinations than the reference concentrations. For the investigated factors, the bioaerosol concentrations were significantly higher during bronchoscope insertion tasks. The time required at the end of the day for the bioaerosols to reach the morning reference concentrations was about fifteen minutes. The average particle sizes were 2.9 μm for the fluorescent particles (bioaerosols) and 0.9 μm for the non-fluorescent particles. Our models based on computational fluid dynamics (CFD) enabled us to observe the behaviour of aerosols for the different rooms.