Biological aerosol transmission characteristics and exposure risk assessment in a typical biosafety laboratory

• CFD - simulated bioaerosol in BSL - 2 lab, verified experimentally. • Airflow key to bioaerosol removal, varies by area. • Bioaerosol deposition rates around 70 % at different sources. • BSC front window has risk, but shows good protection. • Infection risk varies with release source locations. Biosecurity issues have attracted widespread global attention. Biosafety laboratories are important sites for medical testing and scientific research. However, there is a high incidence of laboratory-acquired infections due to improper laboratory personnel practices. There is therefore an urgent need to study the exposure risks of laboratory personnel exposed to biosafety laboratories. In this study, Computational Fluid Dynamics (CFD) was used to simulate biological aerosols generated by improper experimenter handling under three typical scenarios and validated experimentally. The spatial and temporal distribution of biological aerosols was analysed in relation to the flow field and isosurface concentrations. Statistics on deposition rates and contamination levels on different surfaces. Through the flow field of a biological safety cabinet (BSC) and the concentration of biological aerosols within it. Analysed the protective properties of BSCs. Finally, using SARS-CoV-2 as a case study, infection risks in different regions were evaluated. The results show that airflow distribution is a key factor influencing the removal of biological aerosols. No significant difference in biological aerosol deposition rates between release source locations. Nearly 70 per cent of all biological aerosols are deposited on surfaces such as walls, equipment and humans. At the same time a significant portion of the biological aerosols will enter the BSC operating area through the front window opening. This can lead to a potential risk of cross-infection. This study provides guidance for priority disinfection locations in biosafety laboratories and for laboratory personnel to reduce exposure to high-risk areas.