Droplet Generation due to Two Health Care Procedures: A Preliminary Study

Respiratory infections could be spread via exposure to droplets not only from expiratory activities such as talking, coughing and sneezing, and but also from aerosol-generating health care procedures. Droplet sizes predominately determine the times they could remain airborne, the possibility of spread of infectious diseases by large droplets, and thus the strategies for controlling the infections. There has not been any data on the number and sizes of droplets generated in aerosol-generating health care procedures. Experiments were thus carried out to characterize droplets generated in two aerosol-generating health care procedures, i.e. taking nasopharyngeal aspirates and nebulizer therapy. It was found that taking nasopharyngeal aspirates could stimulate coughing and generate large droplets. Nebulizers could generate a large volume of fine droplets ranging from 0.3-20 μm which could escape from the holes in the nebulizer’s facemask.