The global spread of coronavirus disease 2019 poses a significant threat to human health. In this study, recent research on the characteristics of expiratory particles and flow is reviewed, with a special focus on different respiratory activities, to provide guidance for reducing the viral infection risk in the built environment. Furthermore, environmental influence on particle evaporation, dispersion, and virus viability after exhalation and the current methods for infection risk assessment are reviewed. Finally, we summarize promising control strategies against infectious expiratory particles. The results show that airborne transmission is a significant viral transmission route, both in short and long ranges, from infected individuals. Relative humidity affects the evaporation and trajectories of middle-sized droplets most, and temperature accelerates the inactivation of SARS-CoV-2 both on surfaces and in aerosols. Future research is needed to improve infection risk models to better predict the infection potential of different transmission routes. Moreover, further quantitative studies on the expiratory flow features after wearing a mask are needed. Systematic investigations and the design of advanced air distribution methods, portable air cleaners, and ultraviolet germicidal irradiation systems, which have shown high efficacy in removing contaminants, are required to better control indoor viral infection.

2019年冠状病毒病在全球蔓延，对人类健康构成重大威胁。本研究回顾了近期关于呼气颗粒物和流量特征的研究，特别关注不同的呼吸活动，为降低建筑环境中的病毒感染风险提供指导。此外，还回顾了环境对呼气后颗粒蒸发、扩散和病毒活力的影响以及当前感染风险评估的方法。最后，我们总结了针对传染性呼出颗粒的有前景的控制策略。结果表明，空气传播是感染者的一种重要的病毒传播途径，无论是短距离还是长距离。相对湿度对中等大小液滴的蒸发和轨迹影响最大，温度会加速表面和气溶胶中 SARS-CoV-2 的失活。未来的研究需要改进感染风险模型，以更好地预测不同传播途径的感染潜力。此外，还需要对佩戴口罩后的呼气流量特征进行进一步的定量研究。为了更好地控制室内病毒感染，需要系统地研究和设计先进的空气分配方法、便携式空气净化器和紫外线杀菌照射系统，这些系统在去除污染物方面表现出高效能。