Prediction of transmission routes of respiratory infectious diseases in indoor environment: Based on droplet evaporation and sedimentation analysis

Many respiratory infectious diseases are believed to be transmitted from person to person through droplet nuclei in the air or contact with droplet-contaminated surfaces. Most studies related to droplet evaporation only focus on the evaporation process, without dividing the transmission routes of diseases caused by droplet evaporation. In this paper, the actual size of droplet nuclei was analyzed, and droplet evaporation and the changes in component content were predicted. Especially considering the dynamic effect of evaporation on droplets size change, a more realistic sedimentation model was established, and the probability of pathogen transmission through different routes and the corresponding droplet size distribution range were analyzed. The results showed that the size of droplet nuclei and the rate of the evaporation process together determined the time required for droplet evaporation. The number of droplets still suspended in the air after the end of evaporation is much higher than the number of droplets settling on the ground. In addition, the differences in component content during the evaporation process may affect the inactivation of pathogens in droplets. This study provided a reference for the prevention and control strategies of respiratory infectious diseases in indoor environments.